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| Exhibition Hall | Monday, May 9, 2016: 10:45 - 11:45 |
| 2635 | Computer #1 |
Longitudinal Diffusion MRI for Treatment Response Assessment: Preliminary Experience using an MRI-Guided tri-Cobalt 60 Radiotherapy System |
1Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States, 2Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States |
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Diffusion weighted MRI is promising for early prediction of response to radiotherapy 1, 2, and for adaptive radiotherapy, wherein the treatment plan is adapted during treatment based on patients’ response assessed by imaging. Currently DWI-based adaptive radiotherapy is not widely adopted because of scientific and practical challenges. Most importantly, the timing for DWI imaging is not well studied without longitudinal diffusion MRI data at a finer time interval (every 2-5 days) throughout the course of treatment. A recently commercialized MRI-guided radiotherapy system (ViewRay) may eliminate the current challenges and bring diffusion MRI-guided adaptive radiation therapy closer to clinical utility. |
| 2636 | Computer #2 |
MR T1ρ imaging study on normal-appearing brain in patients with nasopharyngeal carcinoma after radiotherapy |
1Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, China, People's Republic of, 2Philips Healthcare, Guangzhou, China, People's Republic of, 3Philips Healthcare, HongKong, China, People's Republic of |
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Radiation induced encephalopathy is one of the most serious complications of radiotherapy (RT) for treatment of nasopharyngeal carcinoma (NPC). In order to detect early radiation-induced changes in gray matter (GM) and white matter (WM) of NPC patients after RT, we recruited NPC patients before RT and after RT with normal-appearing brain for MR T1ρ examination. We found abnormal microstructure changes of WM had already happened in NPC patients after RT even when routine MRI findings are negative. MR T1ρ imaging can be used to detect early radiation-induced changes of WM following RT for NPC patients. |
| 2637 | Computer #3 |
Targeted MRI contrast guided drug delivery: Magnevist and doxorubicin encapsulated into liposomes for detection and treatment of glioma |
1Radiology, College of Medicine Penn State University, Hershey, PA, United States, 2Neurosurgery, College of Medicine Penn State University, Hershey, PA, United States |
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Glioma in its early stage is hard to detect and treat because MRI contrast agent and chemotoxin are not able to cross the blood brain barrier (BBB). The conventional MRI contrast agent such as Magnevist (GD-DTPA) is limited to the cases where the BBB is significantly compromised by the tumor. Present study reports the development of a novel theranostic tool, interleukin-13-liposomes-Magnevist-doxorubicine (IL-13-lip-magnevist-dox) for detection and treatment of glioma. Our results demonstrated that IL-13-lip-magnevist-dox own the potential to specifically target, concomitantly detect and treat glioma in its early stage when BBB is still intact. |
| 2638 | Computer #4 |
Early Prediction and Evaluation of Breast Cancer Response to Neoadjuvant Chemotherapy Using Quantitative DCE-MRI |
1Oregon Health & Science University, Portland, OR, United States |
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DCE-MRI was performed in 28 breast cancer patients (29 tumors) before, during, and after neoadjuvant chemotherapy (NACT). Several DCE-MRI pharmacokinetic (PK) parameters were found to be good early predictors of pathologic complete response (pCR) vs. non-pCR after only one NACT cycle. In addition, several PK parameters and tumor size were significantly correlated with pathologically measured residual cancer burden (RCB). |
| 2639 | Computer #5 |
The USPIO GEH121333 as a dual R1 and R2 Contrast Agent for Imaging Response to Anti-angiogenic Therapy |
1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway, 2Diagnostics, Imaging and Biomedical Technologies, Niskayuna, NY, United States, 3GE Healthcare AS, Oslo, Norway, 4Department of Medical Imaging, St. Olavs University Hospital, Trondheim, Norway |
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Preclinical-phase iron oxide particles (GEH121333), with a high r1/r2 ratio compared to other iron oxide nanoparticles, were used for monitoring vascular response to bevacizumab treatment in ovarian cancer xenografts. Susceptibility contrast MRI using T2 and T2* mapping revealed a treatment induced decrease in blood volume and vessel density, but not in vessel size. Additionally, DCE-MRI using gadodiamide detected a decrease in perfusion and/or permeability. In combination, these two methods provide a comprehensive assessment of anti-angiogenic treatment effects. Lastly, GEH121333 particles induced a strong signal increase in T1w images, which shows promise for its use also as a positive contrast agent. |
| 2640 | Computer #6 |
Assessment of anti-angiogenic efficacy of targeted ECO/siHIF-1α nanoparticles with DCE-MRI and a biodegradable macromolecular contrast agent |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States |
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To apply DCE-MRI with a biodegradable macromolecular contrast agent in assessment of the efficacy of targeted ECO/siRNA nanoparticles for silencing HIF-1α expression for cancer therapy in a mouse colon cancer model. DCE-MRI non-invasively revealed that the treatment resulted in over 70% reduction in average tumor blood flow (Fp), permeability-surface area product (PS), and plasma volume fraction (Vp) in the treatment group as compared to the saline control group (p < 0.05). The treatment was effective to inhibit tumor angiogenesis and proliferation. |
| 2641 | Computer #7 |
Inhibiting 2-hydroxyglutarate production reverses some, but not all, of the MRS-detectable metabolic markers of mutant IDH1 in glioma |
1Radiology, University of California San Francisco, San Francisco, CA, United States, 2Neurological Surgery, University of California San Francisco, San Francisco, CA, United States |
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Mutations in IDH1 are predominant in low-grade gliomas, and inhibitors of the mutant IDH1 enzyme are under investigation as therapeutic agents. Beyond 2-HG production, the IDH1 mutation also induces a broader pattern of 1H-MRS-detectable metabolic alterations. In this study, we investigated whether inhibiting mutant IDH1 using AGI-5198 reverses the metabolic reprogramming observed in IDH1 mutant glioma cells. Our results indicate that AGI-5198 treatment, while completely inhibiting 2-HG production, nevertheless only partially reverses other metabolic alterations and results in a moderate effect on clonogenicity of IDH1 mutant cells. |
| 2642 | Computer #8 |
Assessment of R1 Relaxation Rate Error in DCE-MRI Using Bookend Measurements |
1CMPE, The Christie NHS Foundation Trust, Manchester, United Kingdom, 2Institute of Cancer Sciences, University Of Manchester, Manchester, United Kingdom |
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Dynamic contrast enhanced MRI (DCE-MRI) allows quantitative assessment of tumour status. The addition of a relaxation rate (R1) measurement following the dynamic acquisition in DCE-MRI studies allows the uncertainty in the conversion from signal intensity (S) to R1 to be assessed. In this work the effect of errors in flip angle and pre-contrast signal estimation on the S(t) to R1(t) conversion were evaluated. Results indicated that uncertainty in the measurement of Spre had greater effect than realistic flip angle variations on the S(t) to R1(t) conversion, and that the error was tissue dependent. |
| 2643 | Computer #9 |
Spatial Overlapping between the Subvolumes with Elevated CBV and with Hypercellularity in Glioblastoma |
1Radiology, University of Michigan, Ann Arbor, MI, United States, 2Radiation Oncology, University of Michigan, Ann Arbor, MI, United States |
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Standard imaging for glioblastoma relies on post-contrast T1 and T2 FLAIR MRI sequences, which do not accurately reflect tumor biology. Advanced MRI techniques can define biologically relevant and prognostic features of glioblastoma including perfusion-based volumes with high cerebral blood volume (VhCBV) and high b-value diffusion-based hypercellular subvolume (HCV). We defined VhCBV and HCV in 24 patients with glioblastoma prior to undergoing chemoradiation. Surprisingly, there was little overlap between VhCBV and HCV within individual patients, which suggests that these volumes represent distinct aspects of tumor biology and may be independently prognostic. Analysis of failure patterns and prognostic relevance is ongoing. |
| 2644 | Computer #10 |
Ultrahigh-field (9.4T and 17.6T) magnetic resonance imaging of retinoblastoma: ex vivo evaluation of microstructural anatomy and disease extent |
1VU University Medical Center, Amsterdam, Netherlands, 2Leiden University Medical Center, Leiden, Netherlands |
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Staging of retinoblastoma – the most common pediatric eye cancer – is currently performed in vivo at 1.5 or 3.0 T and allows for images with voxel sizes <0.5x0.5x2 mm3. We performed ex vivo ultrahigh-resolution MRI at 9.4 and 17.6 T of enucleated retinoblastoma eyes. This method allowed us to generate high-resolution images (voxel size: 59x59x59 to 100x100x100 μm3) of different aspects of retinoblastoma showing the potential of ultrahigh-resolution MRI for staging retinoblastoma and gaining insight in anatomical details. |
| 2645 | Computer #11 |
Improved Detection of Recurrent Hepatocellular Carcinomas in Arterial Phase with Multiple Arterial-Phase Volume-Interpolated Breath-Hold Examination |
1Radiology, Henan Cancer Hospital, Zhengzhou, China, People's Republic of, 2MR Collaboration, Siemens Healthcare, Shanghai, China, People's Republic of, 3Radiology, the affiliated Cancer Hospital of Zhengzhou University, Zhengzhou, China, People's Republic of, 4Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 5MR Pre-development, Siemens Healthcare, Erlangen, Germany |
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Overall, 6 arterial sub-phases TWIST-VIBE showed higher detection of recurrent HCCs compared with the equivalent-to-conventional single arterial phase exams by providing an optimized wide observation window for tumor vascularity evaluation. This is especially valuable in improving the detection of hypervascular recurrent HCCs with diameters of less than 2cm. |
| 2646 | Computer #12 |
Multi-parametric MRI at 3.0 Tesla for the Prediction of Treatment Response in Rectal Cancer |
1Radiation Oncology, Liverpool Hospital, Sydney, Australia, 2Faculty of Medicine, University of New South Wales, Sydney, Australia, 3Ingham Institute for Applied Medical Research, Sydney, Australia, 4Faculty of Physics, University of Sydney, Sydney, Australia, 5Radiology, Prince of Wales Hospital, Sydney, Australia, 6Anatomical Pathology, Liverpool Hospital, Sydney, Australia, 7Faculty of Medicine, Western Sydney University, Sydney, Australia, 8Siemens Healthcare Pty Ltd, Sydney, Australia, 9Faculty of Radiation and Medical Physics, University of Wollongong, Wollongong, Australia, 10University of New South Wales, Sydney, Australia |
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A complete protocol using quantitative diffusion weighted imaging (DWI) and dynamic contrast enhanced (DCE) imaging in combination, and a voxel-by-voxel histogram analysis strategy was successfully developed for multi-parametric MRI prediction of treatment response in rectal cancer. In good responders, the week 3 histograms showed a combined shift in distribution of ADC of voxels to higher values and Ktrans of voxels to lower values compared to the pre-CRT. Multi-parametric histogram analysis of ADC and Ktrans appears to be a promising and feasible method of assessing tumour heterogeneity and its changes in response to CRT in rectal cancer. |
| 2647 | Computer #13 |
The study of vascular disrupting agent A64 combined with bevacizumab in the treatment of NSCLC using Multiple b-value DWI |
1Jinan University, Guangzhou, China, People's Republic of, 2guangzhou, China, People's Republic of, 3Guangzhou, China, People's Republic of, 4GE Healthcare MR Research China, Beijing, Beijing, China, People's Republic of |
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Studies showed that vascular disrupting agents and angiogenesis inhibitors had a synergistic effect for the treatment of cancer. Few previous reports used MRI to assess the combination of anti-angiogenesis drugs in non-small cell lung cancer(NSCLC). MR multi-b value diffusion-weighted imaging can be used to monitor the treatment of tumor by anti-angiogenesis drugs. In our study , the nude mice xenograft model was used to evaluate the role of vascular disrupting agents combing angiogenesis inhibitor in NSCLC by multiple b-value diffusion weighted imaging (DWI). |
| 2648 | Computer #14 |
Characterization of Renal Tumors: Initial Experience Integrating Biomechanical and Morphological Assessment Using 3 Tesla Magnetic Resonance Imaging and Elastography (MRE) |
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 2MR Research Collaborations, Siemens Healthcare, Frimley, United Kingdom, 3Department of Radiology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom, 4Urology Centre, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom, 5Department of Histopathology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom |
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Incidentally detected renal tumors are overtreated surgically, as up to 15% of them are benign, most frequently oncocytomas. We hypothesize that integrating biomechanical with morphological MRI assessment can improve lesion characterization, precluding unnecessary surgery. Initial experience and pathological correlation in four resected renal oncocytomas and renal cell carcinomas (RCC) demonstrate that 30Hz MRE with shear modulus elastography parametric mapping is feasible, correlating spatially with gross pathology, with lower viscosity/elasticity (y) ratios [mean = 0.22] in malignant RCCs compared to oncocytomas [mean = 0.46], showing promise for clinical application. |
| 2649 | Computer #15 |
Integrating dynamic contrast-enhanced magnetic resonance imaging and diffusion kurtosis imaging for neoadjuvant chemotherapy assessment in nasopharyngeal carcinoma |
1Radiology, Fujian Provincial Cancer Hospital, Fuzhou, China, People's Republic of, 2Philips Healthcare, Shanghai, China, People's Republic of, 3Philips Healthcare, Hong Kong, Hong Kong |
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DKI is an emerging technique and shows advantage than traditional DWI. Prior DCE-MRI studies suggested it had utility in early monitoring radiotherapy and chemotherapy sensitivity in anti-tumor treatment. However, there are a few studies investigated whether a combination of multi-modalities functional MRI techniques could improve diagnostic efficacy for prediction of anti-tumor outcome. This study enrolled 53 patients who received both DCE-MRI and DKI exams during NAC courses and suggested there were collaboration between DCE-MRI and DKI to early monitor NAC treatments in NPC. In addition, two NAC cycles is a better time point to non-invasive assess NAC response using fMRI. |
| 2650 | Computer #16 |
Apparent Diffusion Coefficient Features Predict Response to Chemoradiation Treatment of Locally Advanced Cervical Cancer |
1Radiology, Ronald Reagon UCLA Medical Center, Los Angeles, CA, United States, 2Radiation Oncology, Barretos Cancer Hospital, Barretos, Brazil, 3Radiological Sciences, Ronald Reagon UCLA Medical Center, Los Angeles, CA, United States, 4Radiation Oncology, Ronald Reagon UCLA Medical Center, Los Angeles, CA, United States |
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FDG-PET is optimal for evaluating and predicting treatment response in cervical cancer; however, developing countries where cervical cancer remains prevalent are more likely to have access to MR than radiotracer. Our prospective study explores the utility of MR for predicting treatment response. Patients with locally advanced cervical cancer underwent MR at baseline, midway through chemoradiation and after chemoradiation. Patients demonstrated robust tumor volume reduction (>93%) and increase in ADC values after treatment. The discriminatory value of the standard deviation of ADC at baseline suggests that tumor heterogeneity may be predictive of response, supporting MR’s role in identifying more aggressive tumors. |
| 2651 | Computer #17 |
Evaluation of the tCho and β-catenin concentration with different molecular biomarkers in breast cancer patients |
1Department of NMR and MRI Facility, All India Institute of Medical Sciences, Delhi, India, 2Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India, 3Department of Pathology, All India Institute of Medical Sciences, Delhi, India, 4Department of Surgical Disciplines, All India Institute of Medical Sciences, Delhi, India |
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We evaluated the correlation of tCho and β-catenin concentrations were correlated with molecular biomarkers (ER, PR and Her2neu) in breast cancer patients. The nuclear β-catenin expression was significantly higher compared to cytosolic expression. A positive correlation between tCho and β-catenin (cytosolic and nuclear fractions) concentrations was seen. The PR- tumors had significantly higher cytosolic β-catenin compared to PR+ tumors. This may be because progesterone acts as an inhibitor of Wnt pathway and thus its absence may lead to increased cytosolic β-catenin in PR- tumors. Results demonstrated role of tCho, β-catenin and progesterone in breast cancer progression. |
| 2652 | Computer #18 |
MRI/MRS–based assessment of lipid metabolism: a new tool for better detection and characterization of breast tumors? |
1GE Global Research Center, Niskayuna, NY, United States, 2Memorial Sloan Kettering Cancer Center, New York City, NY, United States |
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Differential expression of lipid metabolism genes was recently reported in breast cancer patients. In this pilot study, single voxel MRS data was used to assess the spatial and spectral lipid profile of normal volunteers and subjects undergoing neo-adjuvant chemotherapy. Statistically significant differences in lipid profiles from different voxels in single volunteers and between volunteers were found. Moreover, some lipid peak ratios provided good tumor/normal tissue separation. MRI/MRS-based profiling of lipid metabolism may provide a unique tool for better breast cancer tumor detection and characterization. |
| 2653 | Computer #19 |
Metabolic Imaging Biomarker kio Discriminates Breast Tumor Therapy Time-Courses |
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, 2Knight Cancer Institute, Oregon Health & Science University, Portland, OR, United States, 3Diagnostic Radiology, Oregon Health & Science University, Portland, OR, United States, 4Medical Oncology, Oregon Health & Science University, Portland, OR, United States, 5Pathology, Oregon Health & Science University, Portland, OR, United States, 6Surgical Oncology, Oregon Health & Science University, Portland, OR, United States, 7Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR, United States |
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The new DCE-MRI biomarker kio measures on-going vital metabolic activity. For subjects with biopsy-proven breast IDC, it monitors the course of neoadjuvant therapy. While kio decreases for most tumors, for a sub-set it increases during therapy. |
| 2654 | Computer #20 |
Glioblastoma growth and invasion kinetics correlate with MRI ADC metrics |
1Neurological Surgery, Mayo Clinic, Scottsdale, AZ, United States, 2Mayo Clinic, Rochester, MN, United States, 3Pathology, Columbia University, New York City, NY, United States, 4Diagnostic Imaging and Interventional Radiology, H. Lee Moffitt Cancer Center, Tampa, FL, United States, 5Cancer Imaging and Metabolism, H. Lee Moffitt Cancer Center, Tampa, FL, United States, 6Chicago, IL, United States, 7Radiology, Seattle Cancer Care Alliance, Seattle, WA, United States |
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We hypothesize that tumors with different invasiveness indices (D/ρ), as predicted by the Proliferation-Invasion (PI) mathematical model, will exhibit differences in ADC. Segmented tumor volumes were determined on T1Gd and FLAIR MRIs for six GBM patients. The ROIs were used to mask registered ADC maps and parameterize the PI model for calculating D/ρ. Lower quartile ADC values within the FLAIR and FLAIR penumbra ROIs were positively correlated with D/ρ (p=0.041 and p=0.026, respectively). ADC skewness within the T1Gd ROI negatively correlated with D/ρ (p=0.021). Understanding the relationship between D/ρ and ADC could be important for targeting brain tumor therapies. |
| 2655 | Computer #21 |
Characterization of Myxoid Soft Tissue Tumors as Benign or Malignant Using Texture Analysis of the Apparent Diffusion Coefficient |
1Radiology, Samsung medical center, Seoul, Korea, Republic of |
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Myxoid soft tissue tumors (STTs) are histologically unique group of tumors that have been proven to have significantly higher ADC values than nonmyxoid counterparts. In addition, no significant difference of mean ADC value exists between benign and malignant myxoid STTs. We propose texture of ADC value as a new parameter for differentiating benign and malignant myxoid STTs. The global (mean, standard deviation, skewness and kurtosis), regional (intensity variability and size-zone variability), and local features (energy, entropy, correlation, contrast, homogeneity, variance and maximum probability) were extracted from ADC values of each tumor group for texture analysis and statistical comparisons were performed. |
| 2656 | Computer #22 |
Intravoxel incoherent motion (IVIM) imaging for differential diagnosing hepatocellular carcinoma (HCC), hepatic hemangioma and hepatic metastasis. |
1The First Affiliated Hospital of Dalian Medical University, Dalian, China, People's Republic of, 2GE Healthcare, MR Research China, Beijing, Beijing, China, People's Republic of |
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The diffusion property of tumor tissues largely depends on cell density, which may also be predictive features of malignancy in some types of tumors. Intravoxel incoherent motion (IVIM) imaging is an extension of diffusion weighted imaging (DWI) that can be used to investigate both diffusion and perfusion changes in tissues. Comparing the IVIM parameters between carcinoma (HCC), hepatic hemangioma and hepatic metastasis, we found that IVIM can facilitates understanding of tumor tissue characteristics of perfusion and diffusion, and it may provide more useful information to distinguish hemangiomas from other two malignant tumors. |
| 2657 | Computer #23 |
Pairwise metabolite-metabolite correlation analysis (MMCA) of HR-MAS 1H NMR spectra from 407 human brain tumours |
1Molecular Imaging (MRI & MRS), Cancer Research UK Cambridge Institute, Cambridge, United Kingdom, 2Early Clinical Biometrics, AstraZeneca AB R&D, Molndal, Sweden |
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Human brain tumour tissues from glioblastoma multiforme, astrocytoma, meningioma, oligodendroglioma and metastatic tumours were analyzed by metabolite-metabolite correlation analysis of HRMAS 1H NMR spectra from the eTumour database. The following metabolites were quantified using a modified LC-Model basis set: alanine (Ala), choline (Cho), creatine (Cr), lactate (Lac), glutamine (Gln), glutamate (Glu), glycine (Glyn), N-acetylaspartate (NAA), phosphocholine (PCh), phosphocreatine (PCr), taurine (tau), myo-inositol (Ino) and various lipids/macromolecules. The estimated metabolite concentrations from LCModel fittings were used in the investigation of pairwise metabolite-metabolite correlations. Pairwise metabolite-metabolite correlations can serve as an overview of metabolism and can be helpful in understanding the cellular metabolism. |
| 2658 | Computer #24 |
Imbalanced learning techniques for improved classification of paediatric brain tumours from magnetic resonance spectroscopy |
1Institute of Cancer and Geonomic Sciences, University of Birmingham, Birmingham, United Kingdom, 2Birmingham Children’s Hospital NHS foundation trust, Birmingham, United Kingdom, 3Department of Medical Physics,University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom |
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Classification of paediatric brain tumours from Magnetic-Resonance-Spectroscopy has many desirable characteristics. However the imbalanced nature of the data introduces difficulties in uncovering regularities within the small rare tumour type group and attempts to train learning algorithms without correcting the skewed distribution may be premature. By fusing oversampling and classification techniques together, an improved classification performance across different classes with a good discrimination for minority class can be achieved. The choice of learning algorithm, use of oversampling-technique and classifier input (complete spectra versus metabolite-concentration) depends on the data distribution, required accuracy in discriminating specific groups and degree of post-processing complexity. |
| Exhibition Hall | Monday, May 9, 2016: 10:45 - 11:45 |
| 2659 | Computer #25 |
In vitro Imaging of Alanine: Application of CEST MRI |
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States |
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Alanine is a highly abundant non-essential amino acid which provides an alternate source of TCA cycle intermediates for energy and cell survival. It has been shown that myc-driven tumors utilize alanine as an energy source over lactate. Currently, alanine can be detected in vivo only by 13C NMR spectroscopy. Chemical Exchange Saturation Transfer (CEST) MRI is an imaging technique which exploits the properties of exchangeable protons on the molecule for imaging. In the present study, we have shown the in vitro CEST effect of solution containing alanine. |
| 2660 | Computer #26 |
UTILITY OF PET-MRI IN INITIAL STAGING, TREATMENT PLANNING AND FOLLOW UP OF GYNECOLOGIC CANCERS |
1RADIOLOGY, UNIVERSITY HOSPITALS, CASE WESTERN RESERVE UNIVERSITY, CLEVELAND, OH, United States |
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In this exhibit we share our 3 year experience of sequential design PET-MR (Phillips Ingenuity TF PET/MR) application in staging and follow up of gynecologic cancers. Hybrid PET-MR imaging is a new evolving technique and has a useful role in staging, treatment planning and follow up of gynecologic cancers. Standardization of the imaging protocol and understanding its limitations and pit falls is essential before considering regular clinical application. |
| 2661 | Computer #27 |
Automated Segmentation of Ewing’s Sarcoma using Diffusion Weighted Imaging |
1Center for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi, India, 2Department of Biomedical Engineering, All Indian Institute of Medical Sciences, New Delhi, India, 3Department of Radiology, All India Institute of Medical Sciences, New Delhi, India, 4BRA IRCH, All India Institute of Medical Sciences, New Delhi, India |
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Accurate demarcation of tumors on DWI MRimages could play a crucial role in diagnosis and prognosis when using quantitative image analysis like ADC or IVIM. Manual demarcation of tumour on each slice of a 3D stack is usually not feasible. Automated or semi-automated methods of segmentation are thus desirable specifically for DWimages that can be used to identify the tumor region, optimizing on both speed and accuracy. Our results reveals that semi-automated algorithms based on both Otsu-threshold or Active-Contours based region growing perform tumour segmentation with acceptable level of accuracy in diffusion MRimages and reduce time and manual effort required. |
| 2662 | Computer #28 |
How to make a diagnosis and differential diagnoses for superficial soft-tissue solid masses by magnetic resonance imaging: our experiences and initial results |
1Dept. of Radiology, 1st Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China, People's Republic of, 2Hangzhou, China, People's Republic of |
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Superficial soft-tissue masses are common in clinical practice, and most of them are solid. The radiological imaging is available to provide more detailed information, which is more helpful to make a diagnosis and differential diagnosis. Additionally, analysis of imaging features is useful in distinguishing between benign and malignant lesions, which can help make a strategy for therapy , such as preoperative planning of the extent of surgery and whether adjuvant chemotherapy/radiotherapy. Lesions that are assigned benign can be followed expectantly, whereas indeterminate or malignant lesions can be subjected to histological evaluation.The location of a solid mass within the superficial tissue is best described as cutaneous (epidermis and dermis); subcutaneous (adipose tissue, nerve tissue, fibrous tissue and vascular tissue etc.); or fascial (overlying the muscle). Cutaneous lesions may arise in association with the epidermis or dermis, and subcutaneous lesions may arise in the adipose tissue, or the fascia overlying the muscle. However, some lesions can invade the cutaneous and subcutaneous tissue simultaneously. For purposes of comprehensive understanding and analysis, it is most useful to categorize superficial soft-tissue solid masses by histology as skin appendage tumors, mesenchymal tumors and metastatic tumors. |
| 2663 | Computer #29 |
Physics in Motion: Diffusion Weighted Imaging - An Illustrated Review |
1Changi General Hospital, Singapore, Singapore |
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An educational video which uses simple animations to describe the random thermal molecular motion that is diffusion, and how the diffusion process can be demonstrated with the magnetic resonance signal.
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| Exhibition Hall | Monday, May 9, 2016: 10:45 - 11:45 |
| 2664 | Computer #31 |
The Ability to Detect Intracranial Arterial Calcifications: Evaluation of 3D TOF MRA and SNAP |
1Radiology, University of Washington Medical Center, Seattle, WA, United States |
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Intracranial arterial calcification evaluation has shown increasing importance in the literature based on associations with current and future stroke events, dementia and cognitive decline. We hypothesize that the proton-density image, SNAP Ref, that is generated with Simultaneous Non-contrast Angiography and intraPlaque hemorrhage (SNAP) can more adequately assess calcifications compared to 3D TOF MRA relative to the reference standard, thin slice CTA. |
| 2665 | Computer #32 |
Simultaneous multi-slice carotid vessel wall MRI with DIR-FSE |
1Electrical and Computer Engineering, University of Arizona, Tucson, AZ, United States, 2Siemens Healthcare, Tucson, AZ, United States, 3Medical Imaging, University of Arizona, Tucson, AZ, United States, 4Biomedical Engineering, University of Arizona, Tucson, AZ, United States |
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The DIR-FSE sequence is popularly used to assess plaque build up but is known to be a single slice technique due to a non-selective inversion pulse used in the DIR module. In this work we present a technique to improve the SNR efficiency of DIR-FSE sequences by multi-band excitation. The proposed technique can generate multiple slices at the exact null point of blood and the acquired data can be used to create upto 16 TE images and T2 maps for all the acquired slices. |
| 2666 | Computer #33 |
Post-Contrast T1w Black Blood Images of Atherosclerotic Plaque using 3D DANTE prepared Stack of Stars (3D DANTE-SOS) Sequence and ciné Reconstruction Method using Retrospective Ordering and Compressed Sensing (ciné-ROCS) |
1Department of Radiology, UCAIR, University of Utah, Salt Lake City, UT, United States, 2Siemens Healthcare, Salt Lake City, UT, United States, 3Department of Surgery, University of Utah, Salt Lake City, UT, United States, 4Department of Veterans Affairs, VASLCHCS, Salt Lake City, UT, United States |
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Contrast enhanced T1 imaging has been used to aid in the detection of the fibrous cap overlying the necrotic core. We have implemented 3D SOS with retrospective cardiac cycle gated compressed sensing reconstruction to minimize, characterize artifacts in post-contrast imaging. Radial based k-space trajectory may offer reduced motion sensitivity and more robust ciné-ROCS reconstructions due to its inherent oversampling of central k-space. Ciné-ROCS reconstruction from 3D SOS acquisition demonstrates improved demonstration of fine plaque structures and vessel wall movement due to cardiac motion to the regular reconstruction and may help provide information on symptomatic plaque development and response to treatment. |
| 2667 | Computer #34 |
Motion insensitive high resolution in vivo DWI of Carotid Artery Wall Imaging using 3D Diffusion Weighted Driven Equilibrium Stack of Stars (3D DW-DE SOS) sequence |
1Department of Radiology, UCAIR, University of Utah, Salt Lake City, UT, United States, 2Siemens Healthcare, Salt Lake City, UT, United States, 3Department of Surgery, University of Utah, Salt Lake City, UT, United States, 4Department of Veterans Affairs, VASLCHCS, Salt Lake City, UT, United States |
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DWI might provide a tool for discriminating intraplaque hemorrhage and lipid core from other components. Motion insensitive 3D DW-DE SOS has been developed to acquire high resolution DWI to improve the accuracy of ADC measurements. This technique was able to yield high resolution ADC that could provide clear ROI selection for important plaque components. Increased spatial resolution in motion insensitive 3D DW-DE SOS can improve the sensitivity of ADC maps in plaque component identification. The results obtained indicate that an ADC map may be of substantial value in identifying lipid and hemorrhage within overall plaque burden. |
| 2668 | Computer #35 |
Motion Insensitive 3D technique for simultaneous measurement of in-vivo ADC and T2* in Atherosclerotic plaque using a 3D Multiple Echo Diffusion Weighted Driven Equilibrium Stack of Stars (3D ME-DW-DE SOS) Sequence. |
1Department of Radiology, UCAIR, University of Utah, Salt Lake City, UT, United States, 2Siemens Healthcare, Salt Lake City, UT, United States, 3Department of Surgery, University of Utah, Salt Lake City, UT, United States, 4Department of Veterans Affairs, VASLCHCS, Salt Lake City, UT, United States |
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DWI has the potential to provide complementary information that will allow better discrimination of plaque components such as lipid core. Iron has consistently been found in higher concentrations in atherosclerotic plaque compared to vessel tissue. In previous studies, intraplaque T2* distinguished symptomatic from asymptomatic plaques in patients with carotid atherosclerosis. In this work we introduce simultaneous measurement of ADC and T2* using a motion insensitive high resolution 3D multiple echo diffusion weighted driven equilibrium Stack of Stars sequence. This technique can provide high resolution T2* and ADC values simultaneously, which may provide important clinical information to detect plaque progression. |
| 2669 | Computer #36 |
Characterization of carotid plaque using sampling perfection with application-optimized contrast using different flip angle evolution (SPACE) sequence |
1Showa University School of Medicine, Tokyo, Japan, 2Department of Pathology, Showa University Fujigaoka Hospital, Yokohama-shi, Japan |
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The purpose of this study was to investigate whether 3D turbo spin-echo (TSE) SPACE sequence can evaluate plaque characteristics of the carotid artery. Mann-Whitney test was used to examine differences in the contrast ratio (CR) between soft plaques and fibrous plaques on T1- and T2-weighted images. The mean CR of the soft plaques (1.54 ± 0.25) was significantly higher than that of the fibrous plaques (1.17 ± 0.13) (p < 0.001) on T1-weighted images. In conclusion, T1-weighted TSE SPACE sequence can evaluate main components of plaques in the carotid artery with high sensitivity and specificity. |
| 2670 | Computer #37 |
Selective reacquisition for motion artifact reduction in quantitative T2 mapping of carotid artery vessel wall |
1FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 2Oxford Centre for Clinical Magnetic Resonance Research, Division of Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom, 3Section on Magnetic Resonance Spectroscopy, National Institute of Mental Health, Bethesda, MD, United States |
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Ghosting and blurring artifacts caused by swallowing or coughing can be a significant problem in quantitative T2 mapping of atherosclerotic plaque in the carotid artery. The method is based on a multi-slice multiple spin-echo sequence which acquires k-space lines sequentially with a 2 s gap between lines. A navigator echo was added at the end of the echo-train to identify and reacquire data corrupted by motion. The selective reacquisition reduced ghosting and blurring artifacts in healthy volunteer scans with intentional swallowing motion. |
| 2671 | Computer #38 |
Feasibility of Vessel Wall Imaging of the Superficial Palmar Arch using 7T and 3T MRI |
1Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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Evaluation of atherosclerosis in smaller arteries in the hand may be clinically useful in certain disease conditions such as Diabetes. We sought to demonstrate feasibility of vessel wall imaging of the superficial palmar arch using 7T and 3T MRI in comparison with very high frequency micro ultrasound. Results indicated that 7T imaging of the palmar arch was feasible and subjective image quality analysis was better than 3T and ultrasound. |
| Exhibition Hall | Monday, May 9, 2016: 10:45 - 11:45 |
| 2672
|
Computer #49 |
Four-Dimensional, Multiphase, Steady-State Imaging with Contrast Enhancement (MUSIC) with Improved Functional Assessment |
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States |
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A recent proposed technique called four dimensional, multiphase, steady-state imaging with contrast enhancement (MUSIC) enables detailed anatomical assessment of cardiovascular system. However, limited available cardiac phase prevents accurate functional assessment of the heart. In this study, we compared original MUSIC with an improved MUSIC technique that generates double cardiac phases. Initial results suggest a more accurate left ventricular volume measurement and better appreciation of cardiac wall motion can be achieved with more cardiac phases. |
| 2673 | Computer #50 |
Effect of Gadolinium-Induced Susceptibility on First-Pass Single-echo Dixon CE-MRA and Methods for Correction |
1Radiology, Mayo Clinic, Rochester, MN, United States |
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Single-echo Dixon imaging for contrast-enhanced MR angiography (CE-MRA) can provide the advantages of multi-echo Dixon without the tradeoff of longer acquisitions and reduced temporal resolution. Single-echo Dixon imaging assumes that both the water and fat signals are real and have known initial phase and phase due to field inhomogeneities. However, when a paramagnetic Gadolinium-based contrast agent is injected for CE-MRA, the field may be perturbed and render the a priori phase estimates invalid. The purpose of this study is to demonstrate the effect of Gd-induced field perturbations on first-pass single-echo Dixon CE-MRA and describe strategies to avoid or correct artifacts. |
| 2674 | Computer #51 |
Preliminary evaluation of Respiratory Self Navigated Whole-Heart Angiography in Combination with Ultra-small Super-paramagnetic Iron Oxide Particles |
1Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland, 2Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 3Siemens Healthcare Ltd, Camberley, United Kingdom, 4NHS Lothian & Clinical Research Imaging Centre Queen's Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom, 5Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom, 6Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, United Kingdom |
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Respiratory self-navigated 3D-radial MRA is an efficient and robust method for the depiction of coronary luminal anatomy at 1.5T. Higher magnetic fields are more challenging, due to off-resonance artifacts. Contrast-enhanced imaging is usually beneficial. However, variable contrast during prolonged scans can deteriorate the self-navigation signal. Here we investigate the use of an ultra-small super-paramagnetic iron oxide particles (USPIO) contrast agent with longer half-life in combination with self-navigation at 3T. Systolic and diastolic datasets from 10 volunteers were acquired and analyzed. We show that USPIO contrast-enhanced self-navigated coronary MRA is feasible at 3T with good image quality and reliable motion correction. |
| 2675 | Computer #52 |
Feasibility of Subtractionless Three-Station First-Pass Peripheral MRA at 3 T |
1Philips Research, Hamburg, Germany, 2Philips Healthcare, Hamburg, Germany, 3Philips Healthcare, Best, Netherlands, 4Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 5German Heart Institute Berlin, Berlin, Germany |
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Chemical shift encoding-based water-fat imaging, or Dixon imaging, has recently been demonstrated to permit first-pass peripheral MRA without subtraction. While previous work focused on an evaluation at 1.5 T, this work explores the feasibility of this subtractionless method at 3 T. Results on the first six patients are presented and are compared with the established subtraction method. Substantial improvements in image quality are seen, and the use of three stations is, despite particular challenges at 3 T, preliminarily found to be practicable. |
| 2676 | Computer #53 |
International, Multicenter Phase 3 Blinded Study of the Structural Visualization, Diagnostic Efficacy and Safety of Gadobutrol (Gadavist) Enhanced MRA of the Renal Arteries compared to Time-of-Flight MRA using CTA as the standard of reference (SoR) |
1Radiology, Bayer, Whippany, NJ, United States, 2Radiology, Johns Hopkins, Baltimore, MD, United States, 3Radiology, Massachusetts General Hospital, Boston, MA, United States, 4Statistics, Bayer, Whippany, NJ, United States |
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International, multicenter phase 3 blinded study comparing the performance of CE-MRA with Gadobutrol, a high relaxivity and highly stable macrocyclic contrast agent, to 2D Time-of-flight MRA (ToF) using CTA as the standard of reference (SoR). 317 patients suspected of renal artery disease were enrolled. There was almost no error in the Gadobutrol MRA vessel measurements (0.0mm Gadobutrol vs 0.5mm ToF for stenosis measurements) and superior assessability as well as superior specificity was demonstrated reducing the need for additional imaging studies by 50%. Gadobutrol enhanced MRA of the renal arteries has superior visualization, more accurate measurements and is a valuable alternative to CTA without any ionizing radiation. |
| 2677 | Computer #54 |
Lung Perfusion: MRI vs SPECT for screening in suspected Chronic Thromboembolic Pulmonary Hypertension |
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom, 2Radiology Department, Sheffield Teaching Hospitals, Sheffield, United Kingdom, 3Sheffield Pulmonary Vascular Clinic, Sheffield Teaching Hospitals, Sheffield, United Kingdom, 4Institute of Insilico Medicine, The University of Sheffield, Sheffield, United Kingdom |
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A comparison of perfusion SPECT and MRI in screening for chronic thromboembolic disease. To assess the role of MRI perfusion in the clinical imaging pathway in this patient group. |
| 2678 | Computer #55 |
Estimation of Error in Volume Measurement for 100 Intracranial Aneurysms Imaged Serially with CE-MRA at 1.5T and 3T |
1Department of Radiology, UCSF, San Francisco, CA, United States |
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Intracranial aneurysms are localized dilations in blood vessels occurring in 1-6% of the population which can have devastating consequences in the event of rupture. Many aneurysms are asymptomatic, found incidentally, and fall below the surgical size threshold. For this reason, physicians choose to follow aneurysms with imaging rather than opting for surgical or endo-vascular intervention. Here we further our analysis of a previously presented image processing technique using contrast-enhanced MRA to follow intracranial aneurysms longitudinally. We investigate the measurement error of this post-processing technique in 100 intracranial aneurysms, and evaluate the differential effects of imaging at 1.5T and 3T. |
| 2679 | Computer #56 |
Intra-individual quantitative and qualitative comparison of 4D-MRA- and dynamic CTA-bolus-time-curves of gadopentetate dimeglumine and gadobutrol in minipigs |
1Radiology, University of Bonn, Bonn, Germany, 2MR and CT Contrast Media Research, Bayer Healthcare, Berlin, Germany, 3Innovative Technologies, Research Laboratories, Philips Technologie GmbH, Aachen, Germany, 4Department of Radiology, Neuroradiology, Sonography and Nuclear Medicine, Brüderkrankenhaus Trier, Trier, Germany |
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In an animal model bolus kinetics and image quality after injection of 1M gadobutrol (standard and half-dose) and 0.5M gadopentetate dimeglumine (standard-dose) had been investigated in 4D-MRA at 3T and dynamic CTA. The first pass arterial peak Gd-concentrations (quantified by CTA) were higher for standard-dose compared to half-dose gadobutrol. In 4D-MRA the first pass arterial peak enhancement was comparable for both gadobutrol doses and gadopentetate dimeglumine due to peak cut-off effects at high vascular Gd concentrations. Markedly higher venous bolus peaks were found for standard-dose gadobutrol. Image quality of 4D-MRA was rated significantly higher for both doses of gadobutrol. |
| 2680 | Computer #57 |
Evaluate Relative Helicity of Aortic Flow for Marfan Syndrome by 4D Flow Phase Contrast MRI |
1Institute of Systems Neuroscience, Hsinchu, Taiwan, 2Department of Pediatrics, Taipei, Taiwan, 3Center for Optoelectronic Biomedicine, Taipei, Taiwan, 4Department of Biomedical Engineering and Environmental Sciences, Hsinchu, Taiwan |
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We aim to evaluate relative helicity of aortic flow for patients with Marfan syndrome (MFS) by 4D flow phase-contrast MRI. An individual helicityAED mapping was composed to provide the information of the spatiotemporal distribution of relative helicity. The E sign represents the relative helicity cores shown in the early diastole whereas D sign represents the relative helicity core shown time-delayed and downstream. The A sign represents an additional relative helicity core other than D, E, or the normal single cores. MFS patients showed abnormal relative helicity core in helicityAED mapping, which provided promising approaches for patient managements in the future. |
| 2681
|
Computer #58 |
Evaluation of Dual Agent Relaxation Contrast MR Lymphangiography (DARC-MRL) for Pre-surgical Identification of Lymphatic Channels |
1Department of Radiology, University of Washington Medical Center, Seattle, WA, United States |
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A new method of lymphatic channel mapping was evaluated in a retrospective review of pre-surgical lymphedema MR exams. Dual Agent Relaxation Contrast MR Lymphangiography (DARC-MRL) uses intracutaneous injection of a Gd contrast agent for enhancement of lymphatic channels and concomitant intravenous injection of USPIO (ferumoxytol) for suppression of (otherwise lymphatic-obscuring) veins. 43 MR exams using DARC-MRL were compared to 43 matched exams using conventional (no USPIO) MR lymphangiography. Exams were graded for degree of venous contamination, and DARC-MRL exams exhibited dramatically less obscuring venous contamination than the conventional method. |
| 2682 | Computer #59 |
Cardiac and Respiratory Motion-Resolved Free-Running Whole-Heart Coronary MRA of Patients Using 5D XD-GRASP Reconstruction. |
1University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, 3Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland, 4Division of Cardiology and Cardiac MR Center, University Hospital of Lausanne (CHUV), Lausanne, Switzerland, 5Center for Biomedical Imaging (CIBM), Lausanne, Switzerland |
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Free-running self-navigated techniques have been introduced in order to allow for time resolved three-dimensional whole-heart MR acquisitions. A more recently proposed free-running 5D (x-y-z-cardiac-respiration) XD-GRASP (eXtra-Dimensional Golden-angle RAdial Sparse Parallel MRI) approach enables acquisition and reconstruction of cardiac- and respiratory-motion resolved 3D volumes. In this study, we investigated the potential of 5D XD-GRASP in a clinical setting. |
| 2683 | Computer #60 |
MRI of peripheral vascular calcifications using stack-of-stars 3D FLASH |
1Radiology, NorthShore University HealthSystem, Evanston, IL, United States, 2Siemens Healthcare, Chicago, IL, United States, 3Radiology, University of Chicago Pritzker School of Medicine, Chicago, IL, United States, 4Siemens Healthcare GmbH, Erlangen, Germany, 5Radiology, Feinberg School of Medicine, Northwestern Univesity, Chicago, IL, United States |
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We evaluated a novel approach for visualizing and quantifying peripheral arterial calcifications using a stack-of-stars 3D FLASH pulse sequence. The technique permitted isotropic 1mm3 spatial resolution and displayed dark calcifications against a relatively uniform bright background. Banding artifacts relating to chemical shift were minimized by the use of radial in-plane spatial encoding and an in-phase echo time, while vascular signal was enhanced by the use of a low flip angle near the Ernst angle of blood. In patients with peripheral arterial disease, there was excellent correlation using CT angiography as the standard of reference. |
| 2684 | Computer #61 |
Non-Contrast Gate-Free Aortic MR Angiography with Robust Fat Suppression |
1Kumamoto Chuo Hospital, Kumamoto, Japan, 2Philips Electronics Japan, Tokyo, Japan |
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Non-contrast MR angiography (MRA) is a promising method to diagnose and follow-up of vascular diseases such as dissecting aortic aneurysm. Conventionally, 3D gated balanced steady-state free precession (bSSFP) is used for the aorta, but it has several limitations. To overcome bSSFP’s limitations , we propose a new technique based on gradient echo DIXON sequence with flow-independent relaxation-enhanced non-contrast MRA technique (Relaxation-Enhanced Angiography without Contrast and Triggering: REACT). We showed that REACT could provide more robust and stable MRA without any artifacts and failed fat suppression compared with conventional bSSFP. |
| 2685 | Computer #62 |
Time-of-flight unlimited: Novel self-gated unenhanced peripheral MR angiography with continuous table movement in less than 7 minutes |
1Siemens Healthcare, Malvern, PA, United States, 2Radiology, NYU Langone Medical Center, New York, NY, United States, 3Siemens Healthcare, Erlangen, Germany, 4Erwin L. Hahn Institute for MR Imaging, University Duisburg-Essen, Essen, Germany, 5High Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany |
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Although unenhanced MR angiography eliminates the need for contrast injection, it would use ECG triggering which adds extra time and complexity to patient preparation. In the current work, time-of-flight (TOF) unlimited introduces self-gated rapid, radial MR imaging with continuous table movement for seamless coverage of the peripheral vasculature. In-vivo experiments in five healthy volunteers and two patients were performed. Initial results are more than promising and TOF unlimited demonstrates similar image quality compared to conventional ECG triggered TOF despite sevenfold accelerated data acquisition. Thus, novel TOF unlimited may be a time efficient screening tool for peripheral arterial disease. |
| 2686 | Computer #63 |
Reduction of image artifacts in non-contrast-enhanced velocity-selective peripheral MRA at 3T |
1Diagnostic radioloy and nuclear medicine, University of Maryland, Baltimore, MD, United States, 2Radiology, Johns Hopkins University, Baltimore, MD, United States, 3Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of, 4Center for neuroscience imaging research, Insititute for Basic Science, Suwon, Korea, Republic of, 5Vascular and endovascular surgery, University of Maryland, Baltimore, MD, United States, 6Cardiovascular Medicine, University of Maryland, Baltimore, MD, United States |
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Velocity-selective (VS) magnetization-prepared non-contrast-enhanced MR angiography has advantages of large 3D FOV, arbitrary 3D spatial resolution and need for single acquisition only. Peripheral VS-MRA has shown great potential at 1.5T but might be challenging at 3T due to large B0 and B1 inhomogeneity in the pelvis and legs. In this study, we show that the effects of B0 and B1 offsets are manifested as arterial signal loss, stripe artifact and background signal variation. We develop multiple-refocused VS excitation pulses and propose successive applications of two VS preparation pulses with shifted excitation profiles to suppress these artifacts. |
| 2687 | Computer #64 |
Dual-phase coronary MR angiography using image based respiratory navigation |
1Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom |
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Image-based navigation (iNAV) is a promising respiratory motion correction approach for coronary MR angiography (CMRA). However, for dual-phase CMRA the technique may fail due to the different cardiac motion states of the systolic and diastolic acquisition. Here we propose the use of separate independent systolic and diastolic iNAV acquisitions to address this issue. We compared iNAV to the conventional diaphragmatic one-dimensional navigator (1D NAV) in 8 healthy subjects. The proposed technique achieves similar or improved coronary vessel sharpness compared to 1D NAV while reducing dual-phase CMRA acquisition time. |
| 2688 | Computer #65 |
FSE-based Non-Contrast-enhanced Magnetic Resonance Venography for evaluation of the upper extremity veins compared with Contrast-enhanced MRV and Ultrasound |
1Radiology, Austin Health, Melbourne, Australia, 2Radiology, The University of Melbourne, Melbourne, Australia, 3Surgery, The University of Melbourne, Melbourne, Australia, 4Surgery, Austin Health, Melbourne, Australia, 5Centre for Population Health, Burnet Institute, Melbourne, Australia |
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Venous mapping is important in end stage renal disease patients requiring vascular access for hemodialysis. We compare image quality (IQ) and measured vessel caliber of FSE based non-contrast MRV (NC-MRV) to contrast-enhanced MRV (CE-MRV) and US in available segments in 10 healthy volunteers. Central and arm vein IQ was diagnostic, but forearm vein IQ was suboptimal, inferior to CE-MRV. No difference in vessel caliber between sequences was demonstrated for most segments between NC-MRV and CE-MRV, but both MRV techniques yielded significantly larger caliber measurements than US, raising concern regarding application of MRV-derived measurements to clinical practice. |
| 2689 | Computer #66 |
Imaging Deep Inferior Epigastric Perforators with Phase Contrast Magnetic Resonance Angiography: A Feasibility Demonstration |
1Radiology, The Ohio State University, Columbus, OH, United States, 2Plastic Surgery, The Ohio State University, Columbus, OH, United States |
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Currently, MRA is not considered the optimal technique for preoperative imaging of perforators before flap reconstructive plastic surgeries. In this prospective study, we demonstrate that the quality of perforator MRA can be greatly enhanced by using the phase contrast technique. Perforator imaging with PC-MRA not only generates images with better quality and contrast than X-ray and iodinated contrast based CTA, the current clinical gold-standard, but also offers unique features, such as the capability to visualize venous flow and differentiate perforator arteries and veins, that are highly relevant to the design, planning, and execution of DIEP flap reconstructive surgery. |
| 2690 | Computer #67 |
Vessel-selective time-resolved cerebral angiograms in less than one minute |
1FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom |
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Vessel-encoded pseudo-continuous arterial spin labeling (VEPCASL) can be used to obtain vessel-selective time-resolved angiograms. Here we compare accelerated Cartesian and radial readouts to demonstrate the feasibility of speeding up their acquisition, enabling better prospects for use of the method in a clinical setting. It was possible to acquire 2D vessel-selective angiograms in less than one minute. Accelerated (undersampled) radial acquisition consistently led to angiograms with higher signal-to-noise ratio and better quality peripheral artery imaging versus accelerated Cartesian imaging. |
| 2691 | Computer #68 |
Clinically-Acceptable Non-Contrast Thoracic MRA using 3D Radial k-space Sampling and Compressed Sensing |
1Physics, University of Utah, Salt Lake City, UT, United States, 2Radiology, UCAIR, University of Utah, Salt Lake City, UT, United States |
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As an alternative to contrast-enhanced (CE) MRA, we developed an accelerated non-contrast MRA of thoracic aorta using a combination of T2-prepared and fat saturation preparations, b-SSFP readout, 3D radial stack of stars sampling with tiny golden angles, and compressed sensing. This NC-MRA was compared with standard ECG-gated CE-MRA in 8 patients. Normalized signal difference and aortic diameters were not significantly different between CE- and NC-MRA methods. |
| 2692 | Computer #69 |
Non-Contrast MR Angiography with Arterial Spin Labeling: Initial Experience in Pediatric Patients With a 3D Spiral pCASL and CINEMA Protocol |
1Radiology, Phoenix Children's Hospital, Phoenix, AZ, United States, 2Philips, North America, Cleveland, OH, United States, 3Barrow Neurological Institute, Phoenix, AZ, United States, 4Neurology, Phoenix Children's Hospital, Phoenix, AZ, United States |
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This pilot clinical study evaluates the diagnostic utility of a 3D spiral pCASL approach and a 3D dynamic PASL pulse sequence (i.e., CINEMA) in evaluating the neurovasculature in pediatric patients. With increasing recent concerns over the possible deposition of Gadolinium in the brain, a viable clinical protocol that can supplant traditional contrast-enhanced MR angiography is particularly relevant to the pediatric population. Our clinical results in patients ranging from 1 year of age to adolescents demonstrate that both 3D spiral pCASL and dynamic PASL are robust approaches and yield diagnostically useful information that supports clinical findings from conventional TOF angiography. |
| 2693 | Computer #70 |
Pseudocontinuous spin-labeled quiescent-interval slice-selective (QISS) magnetic resonance angiography |
1Radiology, NorthShore University HealthSystem, Evanston, IL, United States, 2University of Chicago Pritzker School of Medicine, Chicago, IL, United States, 3Northwestern University Feinberg School of Medicine, Chicago, IL, United States, 4Siemens Healthcare, Chicago, IL, United States, 5Medicine, NorthShore University HealthSystem, Evanston, IL, United States |
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To describe a pseudocontinuous arterial spin-labeled quiescent-interval slice-selective (pCASL QISS) pulse sequence for vessel-selective nonenhanced MR angiography. |
| 2694 | Computer #71 |
Clinically-Feasible Non-Contrast Abdominopelvic MRA using 3D Radial Stack-of-Stars k-space Sampling and Compressed Sensing |
1Physics, University of Utah, Salt Lake City, UT, United States, 2Radiology, UCAIR, University of Utah, Salt Lake City, UT, United States |
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Quadruple inversion-recovery (QIR), non-contrast (NC) MRA was developed as an alternative to contrast-enhanced MRA, and it performance was evaluated in patients with peripheral arterial disease. The scan time for QIR with respiratory gating, however, is on the order of 10-15 minutes. We sought to accelerate QIR using a combination of 3D radial stack-of-stars sampling with tiny golden angles and compressed sensing (CS). This study shows that 5.3-fold accelerated QIR with radial k-space sampling and CS produces images that are comparable to those produced by original QIR (e.g., 2.7-fold acceleration using GRAPPA). In 10 human subjects, normalized signal difference and vessel dimensions were not significantly different between original QIR and 5.3-fold accelerated QIR with radial k-space sampling and CS. |
| 2695 | Computer #72 |
Pulmonary Magnetic Resonance Angiography: The direct and indirect findings of pulmonary embolism and their mimics |
1Radiology, UW-Madison, Madison, WI, United States, 2Radiology, University of Hamburg-Eppendorf, Hamburg, Germany, 3Radiology, University of California at San Francisco, San Francisco, CA, United States, 4Radiology, University of California at Los Angeles, Los Angeles, CA, United States |
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The use of pulmonary magnetic resonance angiography (MRA) is playing an increasingly important role for the primary diagnosis of pulmonary embolism (PE) and other causes of acute chest pain. We will define appropriate imaging scenarios for the clinical use of this test. Then, using a pictorial essay approach, we will demonstrate the various imaging features that: (A) directly indicates the presence of PE; (2) indirectly suggests the presence of PE; (3) findings that directly show right heart strain; (4) indirect findings suggesting elevated central venous pressure and most importantly; (5) those findings that can mimic PE. After review of these teaching cases, imaging physicians will be able to confidently make the diagnosis of PE on pulmonary MRA examinations. |
| Exhibition Hall | Monday, May 9, 2016: 10:45 - 11:45 |
| 2696 | Computer #73 |
Performance of Self-Calibrated Phase Contrast Correction in Pediatric and Congenital Cardiovascular MRI |
1GE Global Research, Garching bei Muenchen, Germany, 2Dept of Pediatrics, New York-Presbyterian Morgan Stanley Children's Hospital of New York, New York, NY, United States, 3GE Global Research, Niskayuna, NY, United States |
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Phase contrast (PC) MR flow measurements are affected by multiple sources of error, including background phase offsets. The gold-standard approach to correct these offsets involves repeating PC measurements on a static phantom, prolonging each CMR study and impeding exam workflow. Here, we compared the performance of a self-calibrated correction to static-phantom corrected PC data obtained from a pediatric and congenital heart disease population. Self-calibrated correction results showed strong agreement with phantom-corrected data for all vessel types and differed from static-phantom correction by a mean difference in Qp/Qs values of only 0.069. |
| 2697
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Computer #74 |
Analysis and correction of eddy current induced artifacts in spiral phase contrast MRI using Point RESolved Spectroscopy |
1Department of Radiology, University Hospital of Cologne, Cologne, Germany, 2Philips Healthcare, Hamburg, Germany |
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A novel method based on single-voxel-spectroscopy (PRESS) for the analysis and correction of eddy-current induced artefacts in spiral phase-contrast MRI is presented. It is demonstrated, that 0th and 1st order corrections result in residual background offsets of less than 0.5cm/s, inherently correcting for geometrical misalignments between flow acquisitions as well as 2nd order spatial phase offsets. The method does not require special hardware and can be applied as a pre-scan. |
| 2698
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Computer #75 |
ktv-ARC reconstruction for 4D flow MRI using correlations between velocity encodings |
1Technischen Universität München, Munich, Germany, 2GE Global Research, Munich, Germany, 3GE Healthcare, Menlo Park, CA, United States, 4MRI Research Center, University Children Hospital, Zurich, Switzerland, 5GE Healthcare, Munich, Germany |
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4D flow MRI is a powerful tool for visualization and quantification of blood flow. Repeated acquisition of 4 echoes with different velocity encoding is needed to measure flow in 3D. In this study, we propose a new ktv-ARC reconstruction by incorporating correlations between velocity encoded echoes (v) to the spatiotemporal correlations (kt). The error behavior of the method was analyzed on retrospectively undersampled in vivo cardiac data and resulted in more accurate velocity images with ktv-ARC compared to kt-ARC. |
| 2699 | Computer #76 |
Accuracy of relative pressure measurements from 3D PC-MR data using realistic aortic coarctation phantoms |
1Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Santiago, Chile, 2School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile, 3Electrical Engineering Department, Pontificia Universidad Católica de Chile, Santiago, Chile, 4Radiology Department, Pontificia Universidad Católica de Chile, Santiago, Chile, 5Pediatric Cardiology Unit, Hospital Virgen del Rocio, Seville, Spain, 6Institute of Biomedicine of Seville, Universidad de Sevilla, Seville, Spain |
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The aim of this work was to evaluate the accuracy of relative pressures obtained from 3D PC-MRI in a realistic aortic phantom with different grades of aortic coarctations at rest and stress conditions. We also evaluated the accuracy of the relative pressures when subjected to different aortic segmentation and spatial resolutions. The accuracy of the 3D PC-MRI is excellent compared with catheterization values with mild to moderate AoCo at rest and stress conditions. Also, relative pressures were in excellent accuracy with catheterization values when the aortic segmentation only included laminar flow and with higher spatial resolution at rest and stress conditions. However, its accuracy decreases for severe AoCo cases. |
| 2700 | Computer #77 |
4D flow MRI-derived Wall Shear Stress Correlates with Vessel Wall Thickness: Atlases of the Carotid Bifurcation |
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Biomedical Engineering, Erasmus MC, Rotterdam, Netherlands, 3Epidemiology, Erasmus MC, Rotterdam, Netherlands, 4Radiology, Erasmus MC, Rotterdam, Netherlands |
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The purpose of this study is to investigate if, already in early disease, a correlation exists between wall thickness (WT) and wall shear stress (WSS) in the carotid bifurcation. Eleven subjects with plaques in the left carotid arteries underwent 3D-flow-MRI and proton-density-weighted-EPI for WSS and WT quantification, respectively. Relationships between WT and WSS were investigated on an individual basis and using cohort-averaged maps (atlases). Spearman’s ρ averaged over all subjects was -0.28, which was significantly different from 0 (p<0.001). For the atlases, ρ was -0.66 (p<0.001). The atlas approach facilitates more statistical power to show that wall thickening occurs in low WSS regions. |
| 2701 | Computer #78 |
Flow and Structure with Simultaneous Visualization of Registered 4D Flow and Black Blood MRI |
1Department of Medical Physics, University of Wisconsin, Madison, WI, United States, 2Department of Physics, University of Wisconsin, Madison, WI, United States, 3Department of Radiology, University of Wisconsin, Madison, WI, United States |
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In this work, we examined the feasibility of registering 4D-flow MRI scans with different scan sequences, and demonstrate how the incorporation of complementary, registered data can enhance characterization of hemodynamic information. Black blood (BB) and 4D-flow magnitude images demonstrated excellent registration between the pre- and post-rotation data sets, with high values of correlation and good overlap of the vessels between head rotation. Joint visualization of aneurysm 4D flow and BB shows accurate lesion depiction only after registration and is a promising technique for the comprehensive evaluation of vascular pathology. |
| 2702 | Computer #79 |
A Validation Study of Real-time Phase Contrast MRI with Low-Rank Modeling |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua Universiy, Beijing, China, People's Republic of, 2Martinos Center for Biomedical Imaging, Harvard Medical School, Chalestown, MA, United States, 3Department of Radiology, University of Washington, Seattle, WA, United States |
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Conventional phase-contrast (PC) MRI method relies on ECG-synchronized cine acquisition to acquire data over multiple cardiac cycles. The underlying spatiotemporal averaging limits this method to studying pathological irregularities. Real-time PC-MRI is a promising approach to overcome these limitations. Although several techniques have been developed to real-time PC-MRI, few have been fully validated due to the difficulty of acquiring a reference data set as gold standard. This study aims at validating the accuracy of a novel real-time PC-MRI technique through both flow phantom experiments and in vivo experiments. |
| 2703 | Computer #80 |
Validation of compressed sensing accelerated 2D flow MRI in the common carotid arteries |
1Radiology, Academic Medical Center (AMC), Amsterdam, Netherlands |
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Flow MRI of the carotid arteries has emerged as an important imaging field during the last decade and has been shown valuable for the assessment of hemodynamics in the context of atherosclerosis. In this study a 2D flow acquisition was accelerated using random undersampling and compressed sensing reconstruction. For validation of the reconstructed flow a phantom experiment was performed at different acceleration factors followed by an in vivo scan of the carotid arteries. |
| 2704 | Computer #81 |
Effects of 3D-printing technology on flow measurements in patient-specific models of total cavo-pulmonary connection |
1Radiology, University of Wisconsin - Madison, Madison, WI, United States |
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This study investigated the effects of 3D printing technology on flow rates in patient-specific total cavo-pulmonary connection models. 4D flow MRI was used to quantify flow through the Fontan, Glenn, left pulmonary artery and right pulmonary artery in three models at four different flow rates. No statistically significant differences in flow in any of the regions of interest were observed. |
| 2705 | Computer #82 |
4D flow MR imaging for differentiation of pulmonary arterial hemodynamics in pre-capillary pulmonary hypertension |
1Diagnostic Radiology, Tohoku University Hosipital, Sendai, Japan, 2Cardiovascular Medicine, Tohoku University Hosipital, Sendai, Japan, 3Research&Collaborations, Siemens Japan KK, Tokyo, Japan |
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Etiologies of pre-capillary pulmonary hypertension may be associated with pulmonary arterial hemodynamics. This study included 64 patients (pulmonary arterial hypertension [PAH], 25, chronic thromboembolic pulmonary hypertension [CTEPH], 39) who underwent 4D flow and cardiac MR imaging. Backward flow ratio and forward flow eccentricity in the pulmonary trunk as assessed by 4D flow MR and several cardiac MR parameters were different between two diseases. After controlling for age and mean pulmonary arterial pressure, backward flow ratio was the strongest differentiator of PAH from CTEPH. 4D flow has a potential to visualize different pulmonary arterial hemodynamics according to etiologies in pulmonary hypertension. |
| 2706 | Computer #83 |
4D flow MRI Improves Computational Fluid Dynamics Analysis of Aortic Dissection |
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Mechanical Engineering, University of Wisconsin-Madison, Madison, WI, United States |
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The effects of MRI-derived three-directional velocity profiles implemented at the inlet of aortic dissection (AD) computational fluid dynamics (CFD) simulations were investigated. Two AD models were generated from in vivo MRA data using 3D printing. In vitro 4D Flow MRI was performed on the AD phantoms at two flow rates. Normal and multidirectional blood flow vectors at the AD inlet was measured from 4D Flow MRI data and used in CFD simulations. Significant differences were found in pressure distribution in response to inlet boundary condition definitions. Peak velocity and wall shear stress were also affected by inlet condition definition. |
| 2707 | Computer #84 |
4D flow MRI derived energetic biomarkers are abnormal in repaired tetralogy of Fallot patients and may predict deteriorating hemodynamics |
1Pediatric Cardiology, Ann & Robert H Lurie Children's Hospital, Chicago, IL, United States, 2Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL, United States, 3Medical Imaging, Ann & Robert H Lurie Children's Hospital, Chicago, IL, United States, 4Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States, 5McCormick School of Engineering, Northwestern University, Evanston, IL, United States |
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Tetralogy of Fallot (TOF) is the most common form of cyanotic heart disease. As life expectancy continues to increase, MRI plays a central role in evaluation for post-operative complications and reintervention. Current assessment is based on simplified parameters that measure late expression of underlying physiologic changes, with poor outcome prediction. In this study, we explore quantitative 4D flow metrics which may be important measures of hemodynamic efficiency. We found that energetic metrics are abnormal in TOF compared to healthy controls. While these metrics correlated only modestly with routine measurements of ventricular efficiency, they may represent earlier biomarkers of disease progression. |
| 2708 | Computer #85 |
Highly Accelerated 4D Flow MRI with CIRcular Cartesian UnderSampling (CIRCUS) in Patients with Intracranial Aneurysms |
1University of California San Francisco, San Francisco, CA, United States, 2VA Medical Center, San Francisco, CA, United States |
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A highly accelerated 4D flow MRI method with a high tempospatial resolution has been validated in healthy volunteers by comparing to the conventional method. The proposed method been demonstrated to be very promising for imaging the patients with intracranial aneurysms, by achieving an isotropic resolution of 1.3mm and a temporal resolution of 26ms within a 5-minute scan time (R=12). |
| 2709 | Computer #86 |
Non-Contrast Cardiac 4D Flow with Bright Blood and Improved Robustness Using Multiple Thin Slab Acquisition and Variable Density Radial Sampling |
1Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States, 3Global MR Applications and Workflow, GE Healthcare, Munich, Germany |
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Cardiac 4D Flow suffers from blood signal saturation due to whole-volume imaging and limited accuracy if acquired without contrast agents. This work developed and investigated a new multiple thin slab scheme for non-contrast whole-chest 4D Flow. With in-flow enhancement and bright blood, the new sequence provides higher SNR and motion robustness than conventional 4D Flow. The proposed radial golden angle view order ensures smooth slab merging that is insensitive to cardiac and respiratory variations during the scan. |
| 2710 | Computer #87 |
Using MRI to Observe Increased Venous Flow Collateralization in Subjects with Anomalous Jugular Veins |
1The MRI Institute of Biomedical Research, Detroit, MI, United States, 2Physics, University of Ferrara, Ferrara, Italy, 3Department of Gerontology, Wayne State University, Detroit, MI, United States, 4Biomedical Engineering, Wayne State University, Detroit, MI, United States |
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We have established in previous works that a subset of multiple sclerosis (MS) patients show abnormal structure and flow in the internal jugular veins (IJV) when measured with MRI. In this retrospective analysis, we classified and compared extracranial venous collateral flow in MS and normal control samples using MR venography and Phase-contrast flow quantification with a large, standardized dataset. Over 50% of the MS cohort shows a jugular anomaly. The stenotic-MS group shows reduced Type I venous flow compared to healthy controls and non-stenotic MS, while having elevated Type II and Type III flows. |
| 2711 | Computer #88 |
Design and Validation of a Minimum Time Verse Pulse for 4D Flow MRI |
1Department of Radiological Sciences, University of California, Los Angeles, CA, United States, 2Department of Bioengineering, University of California, Los Angeles, CA, United States, 3Physics and Biology in Medicine IDP, University of California, Los Angeles, CA, United States, 4Siemens Healthcare, Los Angeles, CA, United States |
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4D-flow MRI is used to quantify blood flow in a variety of neurovascular pathologies including intracranial aneurysms [1], but is limited by long scan times as well as moderate spatial and temporal resolution. Conventional RF pulses have poor slab profiles that contribute to low sequence efficiency by increasing the field-of-view needed to avoid aliasing in the slab direction. Our objectives were to design a minimum time, high Time Bandwith Product (TBW) VERSE pulse for 4D flow and to validate the improvement in sequence efficiency, confirm flow accuracy, and evaluate total SAR deposition for VERSE+4D-flow compared to our clinical 4D flow imaging protocol. |
| 2712 | Computer #89 |
Contrast-Enhanced 4D Flow Imaging with Reduced Fat Signal |
1Radiology, Stanford University, Stanford, CA, United States, 2Electrical Engineering, Stanford University, Stanford, CA, United States, 3Electrical Engineering & Computer Sciences, University of California, Berkeley, CA, United States |
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Volumetric time-resolved velocity imaging (4D flow) can be used as a single comprehensive sequence to quantify blood flow, evaluate cardiac function, and assess anatomy. However, fat signal can reduce tissue contrast, introduce high-signal-intensity artifacts from motion, and cause errors in velocity quantification. Two approaches are presented for reducing fat signal in contrast-enhanced 4D flow imaging with minimal time penalty. The first approach is a short spectral-spatial RF pulse that reduces fat signal below the level of contrast-enhanced blood pool. The second approach is the introduction of one additional echo with a different TE to separate fat/water for all flow encoding echoes. The performance of these approaches are evaluated in a static phantom study and in patient volunteer studies. |
| 2713 | Computer #90 |
The Communicating Arteries Redistribute Blood Flow in the Circle of Willis with Hypoplastic Segments: Intracranial 4D flow MRI at 7 Tesla |
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Biomedical Engineering & Physics, Academic Medical Center, Amsterdam, Netherlands, 3Spinoza Center for Neuroimaging, Amsterdam, Netherlands, 4Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
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In this study it was investigated if the communicating arteries redistribute blood flow in the circle of Willis (coW) with hypoplastic arteries. For this purpose, 4D flow MRI at 7 Tesla was used in ten healthy volunteers. 50% of the participants had a full coW, whereas 50% had hypoplastic or missing segments. Significant correlations were found for time-averaged blood flow (mL/s) between the left /right posterior communicating artery and the left/right posterior cerebral artery and between the anterior communicating artery and the right anterior cerebral artery. This finding illustrates that flow is redistributed through the communicating arteries in the coW. |
| 2714 | Computer #91 |
Aortic hemodynamics in pediatric Marfan patients compared to healthy pediatric subjects: heterogeneity in the Marfan population |
1Department of Pediatric Cardiology, Willem-Alexander Children and Youth Center, Leiden University Medical Center, Leiden, Netherlands, 2Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, 3Department of Medical Imaging, Ann & Robert Lurie Children’s Hospital of Chicago, Chicago, IL, United States, 4Department of Radiology, Academic Medical Center, Amsterdam, Netherlands, 5Division of Pediatric Cardiology, Ann & Robert Lurie Children’s Hospital of Chicago, Chicago, IL, United States, 6Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Chicago, IL, United States, 7Department of Pediatrics, Ann & Robert Lurie Children’s Hospital of Chicago, Chicago, IL, United States |
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Marfan syndrome (MFS) is a connective tissue disease with high risk of aortic dissection/rupture. Two-thirds of dissections occur in the ascending aorta, one-third in the descending aorta. Diameter plays an important role in risk stratification. However, recent literature has shown diameter only accounts for 50% of the dissections in the descending aortic region. It is not well known how aortic hemodynamics interact with the altered vascular structure of these aortas and how it may impact dilatation. A cohort of MFS children and an age appropriate control group were evaluated with 4D flow MRI: already distinct abnormalities are present in childhood. |
| 2715 | Computer #92 |
Model-based estimation of arterial pulse wave velocity from MRI velocity data |
1GE Global Research, Niskayuna, NY, United States |
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Pulse wave velocity (PWV) is a commonly used surrogate for arterial stiffness. This abstract describes a new method to estimate arterial PWV by using MRI phase-contrast data to tune a 1D blood flow model describing the hemodynamics and propagation of the arterial pulse wave. Results obtained in a single volunteer indicate that the proposed approach could be used with low time resolution methods such as 4D Flow MRI to obtain PWV in the aorta with much lower variability than the foot-to-foot method. |
| 2716 | Computer #93 |
10 fold accelerated 4D flow in the carotid arteries at high spatiotemporal resolution in 7 minutes using a novel 15 channel coil |
1Radiology, AMC, Amsterdam, Netherlands, 2Biomedical Engineering and Physics, AMC, Amsterdam, Netherlands, 3Radiology, UMCU, Utrecht, Netherlands |
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Using a novel 15 channel coil for carotid artery imaging we could prove that the g-factor loss at higher acceleration factors is limited. This permits the use of higher parallel imaging factors than commonly exploited in carotid MRI. A 4D flow scan at high spatiotemporal resolution was accelerated 10 fold (SENSE 4 x 2.5), resulting in high quality images and consistent flow values acquired in a scantime as short as 7 min. |
| 2717 | Computer #94 |
Lower Wall Shear Stress and Abnormal Hemodynamics within the Saccular Aneurysm in Contrast to Fusiform Aneurysm in the Abdominal Aorta. |
1Radiology, Hamamatsu University School of Medicine, Hamamatsu, Japan, 2Radiology, Hamamatsu University Hospital, Hamamatsu, Japan, 3Department of Radiology, Stanford University School of Medicine, Stanford, CA, United States, 4Applied Science Laboratory Asia Pacific, GE Healthcare Japan, Hino, Japan |
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3D cine PC MRI (4D-flow) study of abdominal aorta was conducted to measure wall shear stress (WSS) and to characterize aortic blood flow dynamics within saccular and fusiform abdominal aortic aneurysm and non-dilated aorta. Peak systolic WSS was significantly lower within saccular aneurysm, and stream line analysis depicted separated vortex flow within the saccular aneurysm. The abnormal vortex flow and consequent low WSS of saccular aneurysmal wall may be reflecting the continuing risk of atherogenic changes of the saccular aneurysm in contrast to fusiform aneurysm. |
| 2718 | Computer #95 |
3D Printed Patient-Specific Model for In Vitro Hemodynamic Studies and Comparison with In Vivo Findings Using 4D Flow MRI |
1Radiology, Northwestern University, Chicago, IL, United States, 2Northwestern University, Chicago, IL, United States, 3Radiology & Biomedical Engineering, Northwestern University, Chicago, IL, United States |
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The advent of 3D printing has opened exciting possibilities for biomedical applications. One of the most intriguing of these possibilities is the ability to use images obtained from radiology scanners (CT or MR) to create 3D models of patient anatomy followed by 3D printing. These models will have all the same geometries of patient anatomy to very high detail. In order to have practical applications, however, these 3D models need to behave similarly to human tissue under standard conditions. Our research utilizes patient-specific 3D printed models in an in vitro fluid dynamic circuit to compare 4D Flow MRI data to that of the patient (in vivo). This direct comparison will allow for validation of the 3D printed model for further biomedical application. |
| 2719 | Computer #96 |
Volumetric assessment of kinetic energy and vorticity in the pulmonary artery: alteration of flow hemodynamics in patients with repaired tetralogy of Fallot using 4D flow MRI |
1Radiology, Northwestern University, Chicago, IL, United States, 2Investigacion en Imagen y Resonancia Magnetica Nuclear, Hospital Infantil de Mexico Federico Gomez, Mexico City, Mexico, 3Physics, Universidad Autonoma Metropolitana, Mexico, Mexico, 4Physics, Universidad Autonoma Metropolitana, Mexico City, Mexico, 5Faculty of Physics and Mathematics, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico, 6Pediatric Cardiology, Hospital Infantil de Mexico Federico Gomez, Mexico City, Mexico |
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Flow alterations in the pulmonary artery (PA) of patients with repaired tetralogy of Fallot (rTOF) may be link with elevated kinetic energy (KE). 4D flow MRI allows for the non-invasive volumetric assessment of flow hemodynamics, vorticity, and KE in patients with rTOF in the pulmonary (PA). Thus, the aim was to investigate the impact of flow alterations in the PA and its association with KE and vorticity. |
| Exhibition Hall | Monday, May 9, 2016: 11:45 - 12:45 |
| 2720 | Computer #1 |
Fat suppression using water excitation for improved spatial resolution compared with 2-point Dixon at 3.0 T for DCE breast MRI |
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 2Global MR Applications and Workflow, GE Healthcare, Madison, WI, United States, 3Radiology, University of Wisconsin-Madison, Madison, WI, United States |
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Fat suppression can be achieved in a variety of ways, including using water-only excitation or using a Dixon method. Each of these methods exhibits strengths and limitations. In this work, we evaluated the characteristics of water excitation compared to a 2-point Dixon fat suppression method used in high spatiotemporal resolution DCE breast MRI. |
| 2721 | Computer #2 |
Diagnostic Performance of Maximum Slope as a Novel Kinetic Parameters in High Resolution Ultrafast Dynamic Contrast Enhanced Breast MRI using KWIC |
1Department of Diagnostic Imaging and Nuclear Medicine, Kyoto Univercity Graduate School of Medicine, Kyoto, Japan, 2Breast Surgery, Kyoto Univercity, Kyoto, Japan, 3Siemens Healthcare GmbH, Erlangen, Germany |
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Maximum slope (MS) is a kinetic parameter obtained from the very early phase of ultrafast DCE MRI. Diagnostic performance of MS in breast lesions were compared to washout index (WI), a conventional semi-quantitative kinetic parameters obtained from standard DCE MRI. Ultrafast DCE MRI was obtained using KWIC and analyzed by TWIST Breast Viewer. MS demonstrated significantly higher AUC (0.91) than WI (0.80, p=0.03) with fewer false positive cases of fibrocystic changes than WI. MS is a promising kinetic parameters that provides information complimentary to WI in diagnosing breast lesions. |
| 2722 | Computer #3 |
Breast Tumor Metabolic Imaging Biomarker kio Correlates with Histopathology Residual Cancer Measures |
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, 2Knight Cancer Institute, Oregon Health & Science University, Portland, OR, United States, 3Diagnostic Radiology, Oregon Health & Science University, Portland, OR, United States, 4Medical Oncology, Oregon Health & Science University, Portland, OR, United States, 5Pathology, Oregon Health & Science University, Portland, OR, United States, 6Surgical Oncology, Oregon Health & Science University, Portland, OR, United States, 7Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR, United States |
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The new DCE-MRI biomarker kio measures on-going vital metabolic activity. Whole breast tumor kio correlates well with pathology determinations of residual cancer burden and tumor invasive cell volume fraction from surgical specimens obtained just a few days later. |
| 2723 | Computer #4 |
Pre-treatment DCE-MRI based tumour heterogeneity is associated with traditional prognostic parameters and provides an insight into early recurrence following neoadjuvant chemotherapy in locally advanced breast cancer |
1Centre for Magnetic Resonance Investigations, Hull York Medical School at University of Hull, Hull, United Kingdom |
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Tumours can have high levels of heterogeneity. Lesions demonstrating high levels of heterogeneity have an ‘aggressive’ phenotype. Assessing heterogeneity might provide superior insights into treatment response than traditional mean/median values. The aims of this study were to determine if histogram analysis of pre-treatment DCE-MRI parameters are associated with traditional prognostic indicators and early breast cancer recurrence. Breast dynamic datasets from 208 individuals underwent histogram analysis. U-tests and survival analysis indicated that DCE-MRI histogram parameters are associated with traditional prognostic indicators, have superior prognostic information than mean/median values and provide independent prognostic information regarding breast cancer recurrence prior to therapy initiation. |
| 2724 | Computer #5 |
Amide proton transfer (APT) imaging of breast cancer at 3T MRI: a pilot study |
1Dept of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan, 2Research & Collaboration Dpt., Siemens Japan K.K., Tokyo, Japan, 3Healthcare Sector, Siemens Ltd, Melbourne, Australia |
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Amide proton transfer (APT) imaging is the representative endogenous chemical exchange saturation transfer (CEST) imaging that has been applied to some clinical cancer studies. However, little is known about the clinical usefulness of APT imaging in breast cancer. In this study, 3T MRI studies including APT imaging were performed for 24 breast cancer lesions, and the possible utility of APT imaging in evaluating biochemical information induced by breast cancer was demonstrated. APT CEST imaging is a potentially useful MRI technique for breast cancer. |
| 2725 | Computer #6 |
Repeatability of Diffusion MRI Measurements |
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, 2Epidemiology and Biostatistics, UCSF, San Francisco, CA, United States |
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The purpose of this study was to assess breast tissue measurements using diffusion MRI techniques in repeated studies to evaluate the variability of ADC and FA measurements within- and between-subjects. |
| 2726 | Computer #7 |
Distinguishing pure ductal carcinoma in situ grade using quantitative DWI biomarkers at 3 Tesla |
1Medical Physics and Research Department, Hong Kong Sanatorium&Hospital, Hong Kong, Hong Kong, 2Department of Diagnostic & Interventional Radiology, Hong Kong Sanatorium&Hospital, Hong Kong, Hong Kong, 3Breast Care Center, Hong Kong Sanatorium&Hospital, Hong Kong, Hong Kong |
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This study aims to explore the use of quantitative breast DWI at 3T to distinguish DCIS pathological grades. In a cohort of 30 pathology confirmed pure DCIS, the mean ADC was 1.26±0.19, 1.51±0.29 and 1.13±0.26 x10-3 mm2/s for low (n=5), intermediate (n=9) and high-grade (n=16) DCIS respectively. The high-grade DCIS could be distinguished by the significantly lower mean ADC from non-high grade DCIS (low and intermediate grades, 1.42±0.28 x10-3 mm2/s, p=0.0057). Quantitative DWI has potentials to aid DCIS risk stratification and management. |
| 2727 | Computer #8 |
MRI Biomarkers of breast cancer complete pathologic response to neoadjuvant chemotherapy |
1Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 2Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 3Radiology, University of Chicago, Chicago, IL, United States |
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Neoadjuvant chemotherapy (NAC) is used in breast cancer and pathologic complete response (pCR) is associated with improved survival. Computer extracted MRI features generate quantitative metrics of treatment response. We used an interactive Grow-Cut method to volumetrically segment breast cancers on multiparametric breast MRI pre and post NAC and then computed Haralick features for each sequence. We found a difference in the MRI tumor texture features pre and post NAC. We also found this difference to be statistically significant between tumors with pCR and no-pCR. These metrics demonstrate changes in tumor microenvironment post NAC and are biomarkers for pCR. |
| 2728 | Computer #9 |
Multi-parametric MRI for predicting disease recurrence or death in breast cancer patients following neo-adjuvant chemotherapy. |
1Cancer Research UK Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, United Kingdom |
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The aim of this pilot study was to explore whether functional MRI metrics from a multi-parametric acquisition can predict for disease recurrence or death in breast cancer following neo-adjuvant chemotherapy. 60 months after commencement of the study, a lower R2* value was found at baseline in the women who are alive and disease free, suggesting that these tumours were less hypoxic and better oxygenated than those who developed metastatic disease or died in the interim |
| 2729 | Computer #10 |
Triexponential Diffusion Analysis in Breast Cancer |
1Kanazawa University Hospital, Kanazawa, Japan, 2Kanazawa University, Kanazawa, Japan |
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To acquire more detailed information on perfusion and diffusion in breast cancer, we analyzed three diffusion components using triexponential function. Perfusion-related diffusion (Dp), fast free diffusion (Df), and slow restricted diffusion coefficients (Ds) were calculated from triexponential function. We compared these parameters between invasive ductal carcinoma (IDC) and ductal carcinoma in situ (DCIS) groups. Ds was significantly lower in the IDC group than those in the DCIS group because of difference in the cellularity. Triexponential analysis makes it possible to noninvasively obtain more detailed information on perfusion and diffusion in breast cancer, thereby assisting in the diagnosis. |
| 2730 | Computer #11 |
Analyzing the Texture of Suspicious Lesions in the Female Breast with ADC-mapping in DWIBS and DWI |
1Radiology, German Cancer Research Center, Heidelberg, Germany, 2Medical Physics, German Cancer Research Center, Heidelberg, Germany, 3Heidelberg, Germany, 4Mannheim, Germany |
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Diffusion-weighted imaging (DWI) can be helpful to differentiate benign and malignant lesions in the female breast. We compared the diagnostic performance of conventional DWI and DWIBS (DWI with background suppression) derived ADC maps with different definitions of the region of interest used to measure the ADC value (1.5T Philips). Texture analysis of suspicious breast lesions was performed utilizing ADC mapping in 59 lesions. Statistical analysis revealed the highest accuracy for lesion differentiation if using the mean ADC-value calculated of three small regions-of interest in the DWIBS derived ADC. |
| 2731 | Computer #12 |
Histogram-metrical DCE-MRI based Quantitative Discrimination of Breast Masses |
1Department of Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, China, People's Republic of |
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To clarify the diagnostic efficiency of histogram and mean in tumor detection, this study aims to compare the efficiency of mean and histogram metrics (i.e. skewness, kurtosis, median, variance, entropy and energy) of Ktrans and kep at transverse slice with tumor biggest diameter in discriminating benign lesion, grade II- and III-invasive ductal carcinomas (IDC). The results indicate that in breast DCE-MRI, both mean and histogram-metrics provide roughly comparable values in identifying malignancy from benignancy. However, histogram-metrics are considerably more informative and enable to discriminate pathological grade of IDCs. kep presented better diagnostic efficiency than Ktrans. |
| 2732 | Computer #13 |
Dixon fat-water imaging based variable flip-angle T1 mapping quantification for breast cancer |
1GE Global Research, Bangalore, India, 2University of Cambridge, Cambridge, United Kingdom, 3GE Global Research, Niskayuna, NY, United States, 4GE Healthcare, Leeds, United Kingdom |
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In DCE-MRI, T1 map is necessary for signal to concentration conversion. In highly fat-water mixed tissue such as breast, contrast uptake primarily changes T1 values of water protons. Therefore, DCE quantification in breast cancer must reliably measure water T1. We evaluated T1 maps obtained using Dixon based fat-water separated VFA method and compared values in fat, fibro-glandular tissue and tumors. We observed that T1 mapping with Dixon based VFA method and non-linear fitting recovers T1 values for tissue in breast by reducing partial volume. We conclude that water only T1 mapping will improve accuracy of PK modeling in breast cancer. |
| 2733
|
Computer #14 |
Removing Silicone Artifacts in Diffusion-Weighted Breast MRI by Means of Shift-Resolved Spatiotemporally Encoding |
1Chemical Physics Department, Weizmann Institute of Science, Rehovot, Israel, 2Biological Regulation Department, Weizmann Institute of Science, Rehovot, Israel, 3Unit of Biological Services, Weizmann Institute of Science, Rehovot, Israel, 4Breast Surgery Unit, Meuhedet Clinic, Ashdod, Israel |
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A new ADC-mapping methodology based on SPatio-temporal ENcoding (SPEN) was applied to augmented breasts, organs possessing multiple spectral components. SPEN provides a robust single-shot alternative to echo-planar-imaging (EPI) in terms of overcoming B0-inhomogeneities, while being able to resolve—and thereby suppress—the contributions of different chemical sites. Diffusion SPEN measurements were carried out at 3T on healthy volunteers with silicone-implant augmentation and compared against SE-EPI counterparts, confirming SPEN’s ability to yield more reliable ADC maps, free from the dominant silicone signal contributions, in a single shot. This opens new screening possibilities for cancer detection in breast augmented patients. |
| 2734 | Computer #15 |
Detecting BOLD vasomotor contrast in healthy breast parenchyma and breast carcinoma |
1Department of Radiology, University of Cambridge, Cambridge, United Kingdom, 2Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom, 3Cancer Research UK Cambridge Institute, Cambridge, United Kingdom, 4Institute of Cancer Sciences, University of Manchester, Manchester, United Kingdom |
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Blood oxygenation level-dependent (BOLD) MRI with hyperoxic/hypercapnic gas stimuli has potential to non-invasively probe vascular function, which could help characterize tumors, predict treatment susceptibility and monitor response. This work evaluates BOLD contrast changes in healthy breast parenchyma in response to air and oxygen interleaved with 2% and 5% carbogen gas mixtures, relative to an all-air control. We found that oxygen vs. 5% carbogen was the most robust stimulus for inducing BOLD contrast in the breast. Measurements may be confounded by physiological fluctuations and menstrual cycle changes. Response in breast carcinoma was variable and may indicate underlying differences in vascular function. |
| 2735 | Computer #16 |
Comparisons of pre- and post-treatment intravoxel incoherent motion (IVIM) biomarkers to clinical response in breast cancer patients undergoing neoadjuvant treatment |
1Department of Radiology, Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, NY, United States, 2Memorial Sloan Kettering Cancer Center, New York, NY, United States, 3The Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY, United States |
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Using the intravoxel incoherent motion (IVIM) effect, one can characterize the tumor microenvironment in terms of vascularity and cellularity. Combined with histogram analysis of these IVIM biomarkers, these metrics are compared to clinical responders and nonresponders of neoadjuvent treatment (NAT) in breast cancer patients. We examine the prognostic capabilities of these IVIM metrics and find that (1) certain IVIM parameters significantly differentiate between responders and nonresponders to NAT and (2) IVIM parameters change between pre- and post-treatment MRI scans. This data shows IVIM MRI to be a potentially powerful prognostic tool in breast cancer. |
| 2736 | Computer #17 |
Quantitative magnetic resonance imaging of lymphatic function before and after manual lymphatic drainage in patients with breast cancer treatment-related lymphedema |
1Physical Medicine and Rehabilitation, Vanderbilt University Medical Center, Nashville, TN, United States, 2Radiology, Vanderbilt University Medical Center, Nashville, TN, United States |
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The overall goal of this work is to develop quantitative biomarkers of lymphatic system structure and function using noninvasive 3T MRI. Here, we focus on breast cancer treatment-related lymphedema (BCRL) where we hypothesize quantitative T2 is elevated in patients relative to controls resulting from greater fluid content in the region of interests, and which reduces following manual lymphatic drainage (a commonly performed therapy intervention). Findings suggest abilities to detect changes consistent with intervention-elicited lymphatic dynamics by using internal measures of tissue composition from MRI otherwise not detected using more common limb volume, bioimpedance spectroscopy and tissue dielectric constant measures. |
| 2737 | Computer #18 |
High Resolution DWI with Readout-segmented EPI and computed DWI as a potential alternative of High Resolution Dynamic Contrast Enhanced MRI in evaluating Breast Cancer |
1Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan, 2Breast Surgery, Kyoto University, Kyoto, Japan |
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Eighteen breast lesions underwent high resolution (HR) diffusion-weighted MRI (DWI) with a resolution of 1.1 x 1.1 x 1.4 mm and b value of 0 and 850 sec/mm2 using readout-segmented echo-planar imaging (rs-EPI). Computed (c) DWI with b value of 1200 sec/mm2 were calculated. Lesion conspicuity and maximum size on these images were compared to those on HR DCE MRI. Masses showed relatively good lesion conspicuity on rs-EPI, slightly deteriorated on cDWI. Size was similar between rs-EPI and HR-DCE, while slightly smaller for cDWI. In contrast, NME is often poorly visualized on rs-EPI and cDWI, resulting in underestimation of NME. |
| 2738 | Computer #19 |
Breast MRI for early prediction of residual disease following neoadjuvant chemotherapy: optimization of response cut-point by tumor subtype |
1Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, United States, 3Surgery, University of California San Francisco, San Francisco, CA, United States |
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This study demonstrated the effect of changing the cut-point of the functional tumor volume measured in breast MRI on the prediction of pathologic complete response (pCR) for breast cancer patients undergoing neoadjuvant chemotherapy. The study was performed using the retrospective data of a multi-center clinical trial as a full cohort and in subsets defined by clinically-relevant breast cancer subtypes. Optimal cut-point was selected by minimizing a penalty equation that considered different relative consequences of false negative and false positive predictions. Results showed that the optimal cut-point chosen in subtype had superior negative predictive value than using the one chosen from the full cohort. |
| 2739 | Computer #20 |
Breast imaging changes of invasive cancers on dynamic contrast-enhanced and diffusion-weighted MR Imaging: correlation with molecular subtypes |
1The 1st affiliated hospital of Dalian Medical University, Da lian, China, People's Republic of, 2GE Healthcare, MR Research China, Beijing, beijing, China, People's Republic of |
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This work has evaluated the breast characteristics of invasive cancers on DCE-MRI and DWI assessed as parameters in comparison with different molecular subtypes, and found that they all could provide novel quantitative information reflecting invasive cancers microenvironment changes, with a potential role in the differentiation of molecular subtypes and to facilitate lesion-specific targeted therapies. |
| 2740 | Computer #21 |
Using MRI to assess changes in distribution and leakage of contrast media in murine mammary ducts after intra-ductal injection: intact ducts vs. ducts with in situ cancer |
1Radiology, University of Chicago, Chicago, IL, United States, 2Medicine, Hematology/Oncology, University of Chicago, Chicago, IL, United States |
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Contrast media injected directly into mammary ducts clearly shows mammary gland structure with 3D-MRI. Development of in situ cancer causes changes in the leakage rates and contrast agent distribution in ductal lumens and surrounding tissue. Differences we describe here between FVB/N mice and the SV40Tag mammary cancer mouse model, indicate that in situ cancer significantly changes the permeability of the ductal epithelium. Information gained from imaging these glands following intra-ductal injection can be used to develop new MRI-detectable biomarkers for early detection of in situ cancer, improve understanding of mammary cancer biology, and guide the design of new therapy. |
| 2741 | Computer #22 |
Restriction Spectrum Imaging in Breast Cancer |
1Radiology, UCSD, San Diego, CA, United States |
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Restriction Spectrum Imaging (RSI) is an advanced diffusion imaging technique that has potential to correct for B0 distortions and non-invasively predict tumor grade. This abstract is an initial evaluation of RSI in breast imaging. We evaluated RSI on 11 patients with biopsy proven cancer. Our results indicate that RSI significantly increases conspicuity of cancer relative to the standard ADC. |
| 2742 | Computer #23 |
Combined strategy of histogram-metrical DCE-MRI and DWI in diagnosis of breast masses |
1Department of Radiology, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China, People's Republic of, 2School of Life Science and Technology, Xi' an Jiaotong University, Department of Biomedical Engineering, China, People's Republic of |
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The combined strategy of DCE-MRI and DWI shows promising diagnosis efficiency in breast cancer. This paper is to explore the diagnostic value of combined DCE- MRI and DWI based on histogram-metrical in discriminating breast masses. The results indicate that combined DWI and DCE-MRI based on histogram-metrical analysis have superior efficacy than either DCE-MRI or DWI alone in discriminating breast masses; moreover, the parameters based on histogram-metrical can offer additional features of tumor heterogeneity. |
| 2743 | Computer #24 |
Automated Breast MRI Segmentation Method for Background Parenchymal Enhancement |
1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Surgery, University of California, San Francisco, San Francisco, CA, United States |
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Automated measurements of whole breast segmentation are becoming an essential process to the development of quantitative and reproducible imaging biomarkers. We have developed a method for automated whole breast tissue segmentation and assess its performance using a test dataset, and found approximately 75% of cases had satisfactory segmentation requiring none to minimal manual modification. The current method can likely provide accurate assessment of mean background parenchymal enhancement, but further refinement of breast-chest wall boundary identification is required for other measurements (e.g. breast density). |
| Exhibition Hall | Monday, May 9, 2016: 11:45 - 12:45 |
| 2744 | Computer #25 |
Diffusion and Perfusion Coefficients of Prostate Cancer: Using Intravoxel Incoherent Motion Bi-exponential model |
1Department of Radiology, Tianjin first center hospital, Tianjin, China, People's Republic of, 2Philips Healthcare, Beijing, China, People's Republic of |
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The purpose of the study was to investigate the diffusion and perfusion coefficients among prostate cancer(PCa), normal peripheral zone (PZ) and benign prostatic hyperplasia (BPH) using the IVIM technique. The IVIM was performed at 11 b values of 0, 10, 20, 30, 50, 75, 100, 250, 500, 750 and 1000s/mm2. The perfusion fractions in prostate cancer were significantly higher than those found in the PZ and lower than BPH, which different with some studies. But our results are more consistent with some DCE-MRI studies in tumors Future work will recruit more volunteers and subjects and combined with DCE-MRI for further validation. |
| 2745 | Computer #26 |
Prostate DWI: comparison of a shorter diagonal acquisition to standard 3-scan-trace acquisition |
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 3Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 4Department of Urology, Icahn School of Medicine at Mount SInai, New York, NY, United States |
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Diagonal single shot EPI (SS-EPI) diffusion-weighted imaging (DWI) potentially allows for reduced acquisition time with preserved image quality. In this study, diagonal DWI was compared to standard SS EPI 3-scan-trace DWI of the prostate in terms of image quality and quantitative ADC. ADC values were similar between the 2 sequences (coefficient of variation <4 %). Significant fewer artifacts were observed in the diagonal acquisition. These results show that diagonal DWI can provide substantial reduction in acquisition time (40%) while maintaining adequate image quality. |
| 2746 | Computer #27 |
Feasibility Study of 3-T diffusion tensor imaging of the prostate transition zone: fractional anisotropy Versus apparent diffusion coefficient |
1Radiology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan,China, China, People's Republic of |
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This study is to investigate the diagnostic utility of fractional anisotropy(FA) and apparent diffusion coefficient(ADC) values of diffusion tensor imaging(DTI) to differentiate and classify abnormal signal nodules in prostate transition zone. Eighty-four patients were included in our study and divided into 5 groups: BPH,Gleason score(GS)≤6,GS＝7,GS＝8,GS≥9,measured FA and ADC of the region of interest, using one-way ANOVA to compare the difference among groups. There was significant statistical difference between the groups of FA and ADC values(F＝20.986,P＝0.000; F＝26.560,P＝0.000).Comparison among five groups: just BPH had significant statistical difference(P＝0.000) with other four groups. The FA and ADC values of DTI had higher value for distinguishing benign and malignant nodules, but no obvious advantages in the further classification. |
| 2747 | Computer #28 |
Comparison of performance of quantitative ADC versus PI-RADS v2 assessment for differentiating high-grade from low-grade prostate cancer |
1Brigham and Women's Hospital, Boston, MA, United States, 2Dana-Farber Cancer Institute, Boston, MA, United States |
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One of the challenges in prostate cancer (PCa) management is the ability to differentiate aggressive tumors that require prompt treatment from indolent tumors that can safely undergo active surveillance. To promote global standardization and diminish variation in the acquisition, interpretation, and reporting of prostate multi-parametric MRI (mpMRI) examinations, Prostate Imaging Reporting and Data System (PI-RADS) has been introduced. The second version of PI-RADS (PI-RADS v2) was released early in 2015, but requires clinical validation. Here, we present the results of a study investigating the performance of PI-RADS v2 compared to quantitative ADC (qADC) values in discriminate high-grade from low-grade PCa. |
| 2748 | Computer #29 |
Prostate tissue microstructure: Complementary assessment using multifrequency MR elastography and diffusion tensor imaging in ex vivo human prostate tissue. |
1Neuroscience Research Australia, Randwick, NSW, Australia, 2Prince of Wales Clinical School, University of New South Wales, Kensington, NSW, Australia, 3School of Medical Sciences, University of New South Wales, Kensington, NSW, Australia, 4Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, Lidcombe, NSW, Australia |
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MR elastography (MRE) and diffusion weighted imaging (DWI) techniques are sensitive to microstructural changes, as reflected in the tissue stiffness and water diffusion properties respectively. These results showed that mechanical and diffusion properties varied between fresh and fixed prostate tissue, but were not highly correlated with each other, suggesting that multifrequency MRE and DWI have the potential to be complementary imaging tools for tracking the alterations in soft tissue microstructure, such as those that occur in cancer and other diseases. |
| 2749 | Computer #30 |
Time-Efficient Reduced-Distortion Prostate Diffusion MRI Using Reduced Field-of-View Readout-Segmented EPI |
1Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States |
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The purpose of this study was to minimize echo planar imaging (EPI)-related distortion artifacts while maintaining the time-efficiency for prostate diffusion-weighted MRI (DWI) using a reduced field of view (rFOV) readout-segmented EPI (RESOLVE) technique. Image distortions in clinical standard DW single-shot (ss) EPI (5:52min) were compared with a matched RESOLVE protocol (seven segments, 7:03min) and rFOV RESOLVE (five segments, 4:59min) using the Dice similarity coefficient (DSC) on forward and reverse phase-encoded images. DSC was significantly higher (0.91±0.05) in rFOV RESOLVE compared with the other protocols, indicating that rFOV RESOLVE can improve DWI quality and visualization in the prostate compared with ss-EPI, with higher time efficiency than regular RESOLVE. |
| 2750 | Computer #31 |
Multimodality multiparametric 18F-Fluciclovine PET/MRI for computer-assisted detection of primary prostate cancer: is there a role for SUV? |
1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway, 2St Olavs Hospital, Trondheim, Norway, 3Department of Radiology, St Olavs Hospital, Trondheim, Norway, 4Department of Pathology, St Olavs Hospital, Trondheim, Norway, 5Department of Urology, St Olavs Hospital, Trondheim, Norway, 6Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway |
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Computer-assisted algorithms have been proposed to support radiological reading of multiparametric MRI (mpMRI) images for detection of localized primary prostate cancer. In this work, we investigated if standardized uptake values (SUV) from combined 18F-Fluciclovine PET/mpMRI can improve automated classification of tumor and non-tumor voxels. We found that a PET/mpMRI model (features: T2W, ADC, Ktrans, Ve and SUV) did not significantly improve the area under the receiver operating curve in comparison with an mpMRI-only model (features: T2W, ADC, Ktrans, Ve), suggesting limited additional value of SUV in voxel classification for computer-assisted detection of primary prostate cancer. |
| 2751 | Computer #32 |
Quantitative susceptibility mapping of prostate cancer xenografts |
1Weill Cornell Medicine, New York, NY, United States |
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Quantitative susceptibility mapping (QSM) is a recently developed technique for quantifying magnetic susceptibility and it may be useful in quantifying super-paramagnetic iron oxide (SPIO) nanoparticles for prostate cancer therapy. Previously, researchers have been hampered in extending the use of this technique to cancers outside the brain because of problems such as chemical shift and a large dynamic susceptibility range. Recently developed algorithms, however, allow us to overcome these problems and we demonstrate their use for quantifying SPIO in a prostate cancer xenograft model for magnetic hyperthermia. |
| 2752 | Computer #33 |
Logistic Regression Models May Predict Gleason Grade of Prostate Cancer in the Peripheral Zone but Not the Transition Zone |
1UCL Centre for Medical Imaging, London, United Kingdom, 2Department of Urology, University College Hospital, London, United Kingdom, 3Cellular Pathology, University College Hospital, London, United Kingdom |
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Quantitative imaging metrics forming multiparametric prostate MRI have been shown to correlate with Gleason grade. We therefore aimed to develop logistic regression models which predict aggressive prostate cancer in focal lesions using quantitative MRI parameters. Models were constructed separately for the transition and peripheral zones, using data from 176 examinations.
In the peripheral zone, a combination of 3 simple parameters were found to predict a Gleason 4/5 component with a similar sensitivity and specificity to experienced radiologists. However, performance was relatively poor in the transition zone. Logistic regression models may therefore prove useful when training radiologists to characterise prostate cancer. |
| 2753 | Computer #34 |
Principal Component Analysis Applied to Magnetic Resonance Fingerprinting Data in Prostate |
1Radiology, Case Western Reserve University, Cleveland, OH, United States, 2School of Medicine, Case Western Reserve University, Cleveland, OH, United States, 3Radiology, University Hospitals, Cleveland, OH, United States, 4Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States |
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MR fingerprinting provides a way to generate quantitative information on tissue parameters, giving a set of multidimensional data at each pixel. Having a method to interpret this multidimensional data will aid in an objective and efficient means for differentiating between normal and healthy tissues, or variations between disease states. We apply principal component analysis (PCA) to MRF data along with the apparent diffusion coefficient (ADC) to differentiate between normal and diseased (prostate cancer, prostatitis) tissue within the prostate. |
| 2754 | Computer #35 |
The efficiency of multiparamatric MRI using PI-RADS version 2 in the diagnosis of clinically significant prostate cancer |
1Peking University First Hospital, Beijing, China, People's Republic of |
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Multiparametric MRI (mpMRI) has been well used for detecting prostate cancer and provides helpful information before biopsy. Prostate Imaging Reporting and Data System (PI-RADS version 2), which is a standard protocol for it, need to be evaluated. In this study, we aims to investigated the efficiency and accuracy of mpMRI using PI-RADS version 2 in the diagnosis of clinically significant prostate cancer. Finally, the diagnostic efficiency for clinically significant cancer of mpMRI using PI-RADS version 2 shows good accuracy using PI-RADS. However the consistency of interobserver should be improved in the future. |
| 2755 | Computer #36 |
Prostate Cancer Detection Using Accelerated 5D EPJRESI - sLASER Combined With DWI |
1Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, 2Urology, University of California Los Angeles, Los Angeles, CA, United States |
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Prostate cancer (PCa) is the second leading cause of cancer related death in Western countries. Conventional 3D MRSI in PCa using weighted encoding and long echo time. One dimensional MRSI suffers from overlapping of metabolites. In this study, a non-uniformly undersampled (NUS) five dimensional (5D) echo planar J-Resolved spectroscopic imaging (EP-JRESI) sequence using semi LASER radio-frequency pulses for optimal refocusing was used to record 2D J-resolved spectra from multiple prostate locations and to quantify changes in prostate metabolites, Cit, Cr, Ch and mI after compressed sensing reconstruction of the NUS 5D EP-JRESI data by minimizing total variation method. Also, we found the prostate metabolites ratios (Ch+Cr/Cit and Ch+Cr/mI) were inversely correlated with ADC values. |
| 2756 | Computer #37 |
Prostate tumor growth in patients on active surveillance: is a change in the apparent diffusion coefficient an indicator of an accelerated growth rate? |
1MRI, Royal Marsden Hospital, Sutton, United Kingdom, 2Clinical Magnetic Resonance Unit, Institute of Cancer Research, London, United Kingdom, 3Urology, Royal Marsden Hospital, Sutton, United Kingdom |
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We evaluated relationship between tumor doubling time and ADC in prostate cancer patients managed by active surveillance. Tumor (defined as a low signal-intensity T2-W region showing restricted diffusion and a Type3 contrast-enhanced curve within a biopsy positive octant) volume was calculated at 3 time-points ~12-24mths apart in 22 patients by drawing regions-of-interest on the T2-W images. Mean tumor ADC was estimated centrally through the tumor. Five of 22 tumors (22.7%) showed growth acceleration after the second time-point. A 10% decrease in ADC identified 3 of 4 tumors and missed 1 of 22 cases with a doubling time of <12 months. |
| 2757 | Computer #38 |
Choline metabolism in prostate cancer: relationship between 1H-MRS measured concentrations and uptake of 18F-Choline on PET-CT in the dominant tumor nodule |
1Radiotherapy and Imaging, CR-UK and EPSRC Cancer Imaging Centre, The Institute of Cancer Research and Royal Marsden Hospital, London, United Kingdom, 2Department of Nuclear Medicine and PET/CT, Royal Marsden Hospital, Sutton, United Kingdom |
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Intracellular choline, a putative marker of prostate cancer, may be measured using 1H-MRS, while uptake of extrinsic radiolabelled choline derivatives (11C-choline and 18F-choline) on PET is used to identify prostate cancer. We compared the steady-state concentrations of total choline (1H-MRS) with the uptake of 18F-Choline on PET in a cohort of 11 prostate cancer patients. The measured choline/water ratio in tumor was 0.09±0.02 x10-3 units; the normalized 18F-Choline uptake was 2.69±1.There was a weak negative correlation between measured MRS and early PET uptake (-0.61, p=0.04) suggesting an increased avidity of prostate tumors for choline when internal concentrations are low. |
| 2758 | Computer #39 |
Consistent T1 Quantification in a Multiscanner Setting using Reference Region Variable Flip Angle B1+ Mapping |
1Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, United States |
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The purpose of this study was to demonstrate improved T1 estimation in the prostate using the Reference Region Variable Flip Angle (RR-VFA) B1+ mapping and correction across multiple MRI scanners with different RF transmission modes. Prostate T1 measurements were compared in four volunteers on three MRI scanners before and after B1+ correction. The results showed that, for each volunteer, T1 variations across scanners decreased by 62% after RR-VFA correction, to an average of 10% among scanners, highlighting the need for B1+ correction and the ability to effectively yield precise T1 estimations in a multi-scanner setting using RR-VFA. |
| 2759 | Computer #40 |
Metabolic dynamics of hyperpolarized [1-13C] pyruvate in human prostate cancer |
1Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 2Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 3Radiochemistry & Imaging Probes (RMIP) Core, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 4Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 5GE Healthcare, Toronto, ON, Canada, 6GE Healthcare, Fremont, CA, United States |
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Hyperpolarized (HP) pyruvate has the potential to improve tumor grading and evaluate response to treatment by probing the metabolism of lesions. Three patients with biopsy-proven prostate cancers have been scanned with a 2D dynamic hyperpolarized pyruvate protocol. Repeatability has been evaluated in 2 patients to date. The data from these first 5 injections confirm that HP prostate imaging is feasible and reproducible, and the 2D dynamics will inform 3D static acquisition timing. |
| 2760 | Computer #41 |
Proposal of a novel co-registration and 3D visualization method for comparing prostate tumors on pre-treatment MRI and ablation cavities on post-treatment DCE as a measure of treatment efficacy |
1Bernard and Irene Schwartz Center for Biomedical Imaging, Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Department of Urology, New York University School of Medicine, New York, NY, United States |
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Strategies for the follow-up of focal ablation of prostate cancer combine serial post-procedural PSA, multiparametric MRI examinations, and biopsy, although the optimal follow-up regimen remains controversial. In this study, we propose a co-registration and 3D visualization method for comparing prostate tumors on pre-treatment T2W-MRI and ablation cavities on post-treatment DCE-MRI as a measure of proper treatment coverage. Our preliminary findings suggest that this co-registration method may be used to help assess treatment efficacy. |
| 2761 | Computer #42 |
Voxel level radiologic-pathologic validation of Restriction Spectrum Imaging cellularity index with Gleason grade in Prostate Cancer |
1UC-San Diego, La Jolla, CA, United States |
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Current multiparametric magnetic resonance imaging techniques for detecting prostate cancer are limited with respect to tumor conspicuity assessment, in vivo characterization and localization. We demonstrate that a novel diffusion-based MRI technique, restriction spectrum imaging (RSI-MRI), differentiates among benign, low-grade and high-grade PCa at voxel-level resolution. Using an RSI-MRI index to differentiate between low- and high-grade categories of tumor PCa aggressiveness may help improve and refine diagnosis and staging of PCa. Additionally, because it can detect intratumor variation, RSI-MRI may have particular relevance for planning targeted therapies such as radiation seed therapy placement, MR-guided focused ultrasound surgery, and MR-guided targeted biopsy. |
| 2762 | Computer #43 |
Response of degarelix treatment in human prostate cancer monitored by HR-MAS 1H NMR spectroscopy |
1Molecular Imaging (MRI & MRS), Cancer Research UK Cambridge Institute, Cambridge, United Kingdom |
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Absolute concentrations of metabolites were measured in samples of Benign Prostate Hypertrophy (BPH) and high grade prostate cancer tissues from intact and castrate patients (Degarelix treated). Lactate, alanine, choline compounds concentrations were significantly elevated in high-grade prostate cancer biopsies when compared to BPH samples. Castration resulted in the significant decrease of lactate and t-choline concentrations in high grade prostate cancer biopsies. The reduced metabolite concentrations of lactate and t-choline observed in this study due to Degarelix shows that there is a potential application of in vivo 1H MRS to monitor non-invasively the effects of castration in prostate cancer . |
| 2763 | Computer #44 |
Early detection of recurrent prostate cancer with 18F-Fluciclovine PET/MRI |
1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway, 2St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway, 3Department of Radiology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway, 4Department of Nuclear Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway, 5Clinic of Oncology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway, 6Department of Urology, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway, 7Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway |
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Prostate cancer patients with biochemical relapse (rising PSA) after initial treatment are a diagnostic challenge. Simultaneous PET/MRI combines the excellent soft-tissue contrast of MRI with the high molecular sensitivity of PET in a single imaging session. The aim of this exploratory study is to evaluate detection rate of simultaneous 18F-Fluciclovine PET/MRI for recurrent prostate cancer. The overall detection rate in an initial cohort of 16 patients was 43.8% for combined 18F-Fluciclovine PET/MR. Combined 18F-Fluciclovine PET/MR can detect areas suspicious for prostate cancer recurrence even in patients with very low PSA levels. |
| 2764 | Computer #45 |
MRI-guided prostate biopsies at 3 T – clinical experience with a navigation option |
1Diagnostic and Interventional Radiology Department, Leipzig University Hospital, Leipzig, Germany, 2Urology Department, Leipzig University Hospital, Leipzig, Germany, 3Institute of Pathology, University of Leipzig, Leipzig, Germany |
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Multiparametric MRI has been shown to improve the detection and localization of prostate cancer and is therefore ideally suited for targeting as well. While biopsy guidance in an MRI system typically requires more efforts and time (30‑120 min) than under ultrasound imaging, MRI provides unparalleled contrast of the prostate substructures. Diagnostic detection rates show large variability between patient groups and sites (about 10-60%). With a custom-made navigation option for a commercial device, any intraprocedural MRI data can be used for stereotactic real-time biopsy targeting. This work presents navigation features, indications and clinical biopsy results for a total of 75 patients. |
| 2765 | Computer #46 |
MRI-guided and Tumor-Targeted Biopsy to Inform Focal Therapy in Prostate Cancer |
1Princess Margaret Cancer Centre, Toronto, ON, Canada, 2CHUM, Montreal, QC, Canada |
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We performed MRI-guided biopsy in patients with known localized prostate cancer to confirm MRI findings and guide focal therapy. We found that MRI-guided biopsy had limited impact on the treatment planning process for dose-painted radiotherapy with dose-escalation to tumor-bearing regions. |
| 2766 | Computer #47 |
Comparison of different population-averaged arterial-input-functions in dynamic contrast-enhanced MRI of the prostate: effects on pharmacokinetic parameters and their diagnostic performance |
1Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen, Germany, 2Department of Urology, University Hospital Tübingen, Tübingen, Germany, 3Siemens Healthcare, Siemens Healthcare, Erlangen, Germany |
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The Choice of arterial input function (AIF) is a potential source of variability in DCE-MRI studies. In clinical practice, it’s not always possible to estimate individual AIFs due to artifacts or difficulties in vessel detection, particularly in transversal slices, which are typically acquired for prostate MRI. Therefore, population averaged AIFs (pAIFs) are often used. In the present study we assessed the effect of different pAIFs on parameter estimates in DCE-MRI of the prostate. We found that choosing various pAIF types causes high variability in pharmacokinetic parameter estimates. Therefore, it is important to keep AIF type selection constant in DCE-MRI studies. |
| 2767 | Computer #48 |
Validation of a diagnostic transition zone prostate cancer model trained in a 1.5T MRI scanner on an independent cohort of patients scanned on a 3T MRI scaner. |
1Centre of Medical Imaging, UCL, London, United Kingdom, 2Department:Research Department of Urology, UCL, London, United Kingdom, 3Div of Surgery & Interventional Sci, UCL, London, United Kingdom, 4Histopathology, UCL, London, United Kingdom, 5Radiology, UCL, London, United Kingdom |
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Diagnostic models for classifying prostate cancer within the transition zone based on multi-parametric magnetic resonance imaging (mp-MRI) have been proposed to improve radiologist’s performance. Such diagnostic models are trained on mp-MRI data acquired at 1.5T or 3T MRI scanners, but to the best of our knowledge no-one has yet examined whether these magnet specific models are interchangeable. This work applied a previously published diagnostic model trained on mp-MRI data acquired at a 1.5T scanner, on an independent cohort of patients with mp-MRI data acquired at a 3T and found that the performance of the model doesn’t drop significantly. |
| Exhibition Hall | Monday, May 9, 2016: 11:45 - 12:45 |
| 2768 | Computer #49 |
Ethanolamine Kinase-1 as a Potential Therapeutic Biomarker in Pancreatic Cancer |
1Radiology, Johns Hopkins University, Baltimore, MD, United States, 2Utrecht, Netherlands |
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In understanding the aberrant choline metabolism of cancer, significant effort has been focused on phosphocholine (PC) but the role of phosphoethanolamine (PE) is relatively underexplored, even though tumors show increased PE as consistently as increased PC. Our previous findings in breast cancer cells have led us to expand our study to understand the role of ethanolamine kinase-1 (EtnK-1) and PE in pancreatic cell lines. We have demonstrated that EtnK-1 is the major contributor to PE levels in these cells and may be a potential therapeutic target. |
| 2769 | Computer #50 |
Pancreatic cancer stromal characterization using diffusion tensor imaging and collagen 1 fibers in xenograft model |
1JHU ICMIC program, Division of Cancer Imaging Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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The dense desmoplastic stroma present in pancreatic ductal adenocarcinoma (PDAC) limits the delivery of diagnostic imaging probes and therapeutic agents leading to poor prognosis of PDAC from a combination of late-stage diagnosis and limited response to chemotherapy. Collagen 1 (Col1) fibers form a major component of this desmoplastic stroma. By combining noninvasive diffusion MRI with optical imaging we characterized the relationship between Col1 fibers and diffusion MRI in PDAC. A good correlation was observed between Col1 fibers and diffusion MRI parameters providing a rationale for detecting PDAC with diffusion MRI, and characterizing the relationship between Col1 fibers and diffusion MRI. |
| 2770 | Computer #51 |
Measurement of Arteriolar Blood Volume in Brain Tumors Using MRI without Exogenous Contrast Agent Administration at 7T |
1Department of Medical Imaging, Nanfang Hospital, Southern Medical University, Guangzhou, China, People's Republic of, 2Neurosection, Div. of MRI Research, Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 4Division of Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 5Department of Radiology, C.J.Gorter Center for High Field MRI, University Medical Center, Leiden, Netherlands |
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The purpose of this study is to evaluate the potential diagnostic value of inflow-based vascular-space-occupancy (iVASO) MRI in brain tumor patients by comparing it with the widely used dynamic-susceptibility-contrast (DSC) MRI. The iVASO approach can measure arteriolar cerebral blood volume (CBVa) without using an exogenous contrast agent. The measured CBVa by iVASO showed a stronger association with tumor grade than DSC CBV. As the total scan times for iVASO and DSC are comparable, iVASO MRI may be a useful alternative for the assessment of tumor perfusion, especially when exogenous contrast agent administration is difficult or contraindicated in certain patient populations. |
| 2771 | Computer #52 |
An Extended Linear Reference Region Model that accounts for plasma volume in Dynamic Contrast Enhanced MRI |
1Medical Physics Unit, McGill University, Montreal, QC, Canada, 2Research Institute of the McGill University Health Centre, Montreal, QC, Canada |
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The reference region model allows quantification of tumour perfusion through DCE-MRI without needing an arterial input function. One limitation is that the model does not account for plasma volume which could be non-negligible in highly vascularized tissues such as tumours. This study introduces a reference region model that accounts for the plasma volume. The performance of this model is evaluated in simulation and invivo data.
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| 2772 | Computer #53 |
Test-retest stability of MTT insensitive CBV leakage correction in DSC-MRI |
1The Intervention Centre, Oslo University Hospital, Oslo, Norway, 2Dept. of Physics, University of Oslo, Oslo, Norway, 3Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States, 4Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States, 5Center for Neuro-Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, United States, 6Siemens Healthcare Health Services, Malvern, MA, United States, 7MGH-HST A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States |
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Contrast agent extravasation is known to be a serious confounder in estimations of cerebral blood volume (CBV) analysis of primary brain tumors using DSC-MRI. We here propose a modified MTT-insensitive method for correction of contrast agent extravasation based on parametric analysis of the tissue impulse response function from a two-compartment kinetic model combined with automated global arterial input function (AIF) approximation. Using DSC-MRI data from 28 patients with recurrent glioblastoma which were scanned twice prior to treatment initiation, we show that the proposed method yields test-retest stability similar to the current reference method, but with the added advantage of reduced MTT sensitivity. |
| 2773 | Computer #54 |
Differential Diagnosis of Giant Cell Tumor and Chordoma in the Spine by Using Morphological Features and Pharmacokinetic Parameters Analyzed from DCE-MRI |
1Department of Radiology, Peking University Third Hospital, Beijing, China, People's Republic of, 2Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, CA, United States |
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26 patients with giant cell tumor in the spine and 12 patients with chordoma received DCE-MRI were analyzed. The morphological features (lesion location, vertebral compression, paraspinal soft tissue mass, bone expansion change, fiber separation, and MR signal on T1W1 and T2W1) and DCE pharmacokinetic parameters were compared. Several typical morphological features could be used for differential diagnosis, but there was a substantial overlap. DCE-MRI may provide very helpful information. Giant cell tumor had a significantly higher Ktrans and kep compared to chordoma, and by using a cut-off value of kep=0.43/min, it could achieve a very high accuracy of 95%. |
| 2774 | Computer #55 |
Characterization of Metastatic Cancer in the Spine by DCE-MRI: Comparison of Heuristic and Pharmacokinetic Parameters Analyzed from DCE Kinetics |
1Department of Radiology, Peking University Third Hospital, Beijing, China, People's Republic of, 2Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, CA, United States |
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A retrospective DCE-MRI of 76 patients with different metastatic cancers in the spine (35 lung, 11 thyroid, 12 breast, 7 prostate, 7 liver and 4 kidney) were studied. Three heuristic parameters: the maximum and steepest wash-in signal enhancement ratio and the wash-out slope were measured. Two-compartmental pharmacokinetic analysis was performed to obtain Ktrans and kep. The maximum and wash-in SE ratio were highly correlated with Ktrans; and the wash-out slope was highly correlated with kep. The lung cancer had the widest variation, the breast cancer had the highest wash-in SE ratio, and the thyroid cancer had the greatest wash-out slope. |
| 2775 | Computer #56 |
DCE-MRI Evidence of Biological Changes in Irradiated Healthy Muscle Following Chemoradiotherapy Treatment of Head and Neck Cancer |
1International School of Beaverton, Beaverton, OR, United States, 2Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, 3Department of Radiation Oncology, U.T. MD Anderson Cancer Center, Houston, TX, United States, 4Department of Imaging Physics, U.T. MD Anderson Cancer Center, Houston, TX, United States, 5Department of Radiation Oncology, Case Western Reserve University, Cleveland, OH, United States, 6Department of Radiation Physics, U.T. MD Anderson Cancer Center, Houston, TX, United States, 7Department of Head and Neck Surgery, U.T. MD Anderson Cancer Center, Houston, TX, United States, 8Harvard Medical School, Boston, MA, United States |
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Head and neck cancer patients are commonly treated with chemoradiotherapy as standard of care. Although the conventional wisdom is that radiation does not cause long-term adverse effects in healthy, well-perfused tissues such as muscle, few studies have evaluated potential biological changes in irradiated muscle tissues longitudinally during the course of treatment. Here, we report preliminary findings of such changes as measured by Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCE-MRI) before, during, and after chemoradiotherapy treatment of a subset of human papilloma positive (HPV+) oropharyngeal cancer (OPC). |
| 2776 | Computer #57 |
Reliability of DCE pharmacokinetic parameter values for quantitative longitudinal assessment of brain tumors |
1Functional Brain Center, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel, 2Functional Brain Centerasky Medical Cente, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel, 3Department of Chemical Physics, Weizmann Institute, Rehovot, Israel, 4Neuro-Oncology Service, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel, 5Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel-Aviv, Israel |
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DCE-MRI parameters have been shown to be useful for therapy response assessment in patient with glioblastoma, yet the estimated parameters may show high variation in their values. This study investigated the reliability of DCE parameters for quantitative longitudinal assessment of brain tumors. 14% standard-deviation in the WM and 12% in the GM, were detected for vp in healthy subjects(n=27). Results from six patients showed mean differences of 3.2%/9.7% in vp for WM/GM in the hemisphere contralateral to the lesion, comparing two longitudinal scans. Parametric-response-maps calculated within lesion areas based on the threshold values from the healthy controls supported radiological assessment. |
| 2777 | Computer #58 |
DWI and DCE-MRI for imaging diagnosis on vasculogenic mimicry and predicting responses to vascular-disrupting therapy on primary liver cancers in rats |
1Theragnostic Laboratory, MoSAIC, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Leuven, Belgium, 2Renji Hospital, Shanghai Jiao Tong University, School of Medicine, Department of Nuclear Medicine, Shanghai, China, People's Republic of, 3Laboratory of Lipid Metabolism and Cancer, Department of Oncology, Faculty of Medicine, KU Leuven, Leuven, Belgium, 4Radiopharmacy, Department of Pharmaceutical and Pharmacological Sciences, Faculty of Medicine, KU Leuven, Leuven, Belgium, 5Biomedical MRI, MoSAIC, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Leuven, Belgium, 6Radiology, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Leuven, Belgium |
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Vasculogenic mimicry (VM) refers to tumor cells mimicking endothelial cells and directly participating in blood vessel formation, which appears in 2 distinctive forms, namely, the tubular type and the patterned matrix type. In liver cancer, VM is associated with tumor aggressiveness and poor clinical outcome. DENA-induced primary liver cancer model in rat appears an optimal VM model with both the 2 VM types. DWI and DCE-MRI were used to characterize and distinguish different VM types, and sensitively predicting diverse therapeutic responses to a vascular-disrupting agent CA4P. |
| 2778 | Computer #59 |
MR prediction of Tumor Burden in Patient-Derived Mouse Xenografts Model of Glioblastoma using an Adaptive Model |
1Henry Ford Hospital, Detroit, MI, United States, 2Oakland University, Rochester, MI, United States, 3Shahid Beheshti University, Tehran, Iran |
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In human glioblastoma multiforme (GBM), infiltrating cells are found in remote locations, even in the hemisphere contralateral to the primary lesion. Although MRI allows approximation of the extent of tumor cell infiltration, the actual extent of infiltration may be greater or less than the edema, and there is no standard MRI practice that can be used to assess the infiltrating tumor burden. This pilot study investigates the feasibility of using a set of MR modalities for the development of an MRI estimate of infiltrating tumor burden in Patient-Derived Mouse Xenografts model of GBM using an adaptive model. |
| 2779 | Computer #60 |
Automatic Segmentation and Classification of Glioblastoma using DCE-MRI |
1Functional Brain Center, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel, 2Functional Brain Centerasky Medical Cente, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel, 3Department of Chemical Physics, Weizmann Institute, Rehovot, Israel, 4Neuro-Oncology Service, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel, 5Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel-Aviv, Israel |
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Segmentation of lesion area in patients with glioblastoma (GB) into active tumor, tissue necrosis, vasogenic edema and infiltrative disease, is highly important for patient monitoring, yet is challenging using standard radiological assessment. The aim of this study was to segment the lesion area into these four tissue types in GB patients. Voxel-wise classification was performed using support-vector-machine based on anatomical and DCE-MRI parameters. Significant differences were detected between the tissue types for FLAIR, vp, and ktrans. Sensitivity and specificity of the training-set were measured based on 2-fold-cross-validation analysis, showing high sensitivities and specificities of 94-100% for the different tissue types. |
| 2780 | Computer #61 |
Can FS-T2/ASL fusion image be an alternative to T1 enhanced imaging in Nasopharyngeal carcinoma? |
1Cancer Hospital, Chinese Academy of Medical Sciences, Beijing, China, People's Republic of, 2GE Healthcare MR research China, Beijing, Beijing, China, People's Republic of |
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Tumor extent assessment of NPC is critical for delineating the radio-therapeutic target region. We aimed to investigate the use of the fusion images of fat suppressed (FS)-T2 with arterial spin labeling (ASL) in measuring the volume of NPC. Two observers measured the volume of 21 untreated NPC using FS-T2, FS-T2/ASL (with PLD=1.0, 1.5 and 2.0s) fusion images and enhanced-T1WI separately. Compared to those obtained using FS-T2 alone, measurements made using FS-T2/ASL were more consistent with those made using enhanced-T1WI. The FS-T2/ASL fusion image has the potential to be an alternative to enhanced-T1WI, when contrast administration can not be performed. |
| 2781 | Computer #62 |
Comparison of DCE-MRI using Gd-EOB-DTPA and Gd-DTPA for tumor vascularity evaluation for hepatoma: preclinical study using rat orthotopic hepatoma model. |
1radiology, Asan medical cencer, Seoul, Korea, Republic of, 2Siemens Healthcare, Seoul, Korea, Republic of |
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For evaluation of tumor vascularity of hepatoma, we aim to compare the DCE-MRI using Gd-EOB-DTPA and Gd-DTPA. When we perform DCE-MRI twice with 24-hours interval: first scan using Gd-DTPA and second scan using Gd-EOB-DTPA, the time-intensity curve patterns were quite different between the two scans. These findings imply that Gd-DTPA distributes between blood vessels and EES, working as a extracellular contrast agent, whereas Gd-EOB-DTPA distribute blood vessels, EES, and intracellular space in the hepatoma, working as a hepatobiliary contrast agent. Therefore, the conventional two-compartment model does not fit DCE-MRI using Gd-EOB-DTPA in subjects with hepatoma which may express OATP receptors. |
| 2782 | Computer #63 |
Similarity of In Vivo Lactate T1 and T2 Relaxation Times in Different Preclinical Cancer Models Facilitates Absolute Quantification of Lactate |
1Memorial Sloan Kettering Cancer Center, New York, NY, United States |
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Aggressive, treatment-resistant tumors have been associated with high tumor lactate. For the absolute quantification of in vivo tumor lactate by the substitution method, it is essential to correct for differences between reference phantom and in vivo lactate T1 and T2 relaxation times (LacT1/T2). The LacT1/T2 acquisition requires specialized MR sequences and is hampered in vivo by long acquisition times and low lactate SNR. Here, we measure LacT1/T2 for various orthotopic breast and subcutaneous prostate cancer models in immune-competent and immune-compromised hosts. Our results indicate that using an average LacT1/T2 correction factor introduces less than 20% error in the lactate quantification. |
| 2783 | Computer #64 |
Multiparametric MRI of a transgenic mouse model of neuroblastoma using an asymmetric high resolution 3-channel/3-animal RF coil on a clinical 3T platform |
1Radiotherapy and Imaging, The Institute of Cancer Research, London, United Kingdom, 2The Institute of Cancer Research/ Royal Marsden NHS Foundation Trust, London, United Kingdom, 3Cancer Therapeutics and Clinical Studies, The Institute of Cancer Research, London, United Kingdom |
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The use of clinical MRI scanners to conduct preclinical research facilitates a more direct or matched comparison with clinical studies. The increased use of orthotopic and transgenic mouse tumour models in cancer research demands non-invasive methods to accurately assess their progression and treatment response in vivo. The purpose of this study was to evaluate the utility and sensitivity of anatomical and functional MRI data/biomarkers acquired from transgenic mouse models of neuroblastoma using a non-bespoke asymmetric high resolution RF coil on a clinical 3T scanner. |
| 2784 | Computer #65 |
Early MRI findings after Near Infrared Photoimmunotherapy in an animal model |
1Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, Bethesda, MD, United States |
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Near infrared photoimmunotherapy (NIR-PIT) is a new cancer treatment that combines the specificity of antibodies for targeting tumors with the toxicity induced by photon absorbers after irradiation with NIR light. The purpose of this study was to determine if MR imaging can detect changes in the MR properties of tumor within several hours of NIR-PIT in an animal model. Prolongation of T2, reductions in apparent diffusion coefficient (ADC) and increased enhancement using gadofosveset are seen within 2 hours of NIR-PIT treatment of tumors. Thus, MRI can be a useful imaging biomarker for detecting early therapeutic changes after NIR-PIT. |
| 2785 | Computer #66 |
Imaging of Nuclear Overhauser Enhancement in Human Brain Tumor at 3 Tesla |
12nd Affilicated Hospital, Shantou University Medical College, Shantou, China, People's Republic of, 2Hanshan Normal University, Chaozhou, China, People's Republic of |
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Our aim was to demonstrate the feasibility of nuclear Overhauser enhancement (NOE) imaging to detect the characteristic of patients with brain tumors. Six healthy volunteers and eleven patients with brain tumors were recruited for undergoing MRI scan at 3T. As a result, we found NOE value was greater in white matter compared to gray matter. However, in human brain tumors, NOE value was slightly hypointense in glioma and little difference in meningioma. NOE imaging may help to distinguish the heterogeneity of benign or malignant tumors, and it is important in diagnosis and treatment planning for patients with brain tumors. |
| 2786 | Computer #67 |
31P and 1H MRS of Androgen-Independent and Androgen-Dependent Prostate Cancer Xenografts: Lonidamine Selectively Decreases Tumor Intracellular pH, Bioenergetics and Increases Lactate |
1University of Pennsylvania, Philadelphia, PA, United States, 2Thomas Jefferson University, Philadelphia, PA, United States |
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Lonidamine (LND) effects were measured in vivo by 31P and 1H MRS in androgen-independent (PC3) and androgen-dependent (LNCaP) prostate cancer xenografts indicating a sustained and tumor-selective decrease in intracellular pH (pHi) and extracellular pH (pHe), and decrease in tumor bioenergetics (βNTP/Pi) by 75.0 % and 79.0 % in PC3 and LNCaP, respectively, relative to the baseline levels. Steady-state levels of tumor lactate were significantly increased ~ 2 fold at 60 min. post-LND. The decline of pHi, pHe, bioenergetics and increase in lactate produced increased therapeutic efficacy when LND was combined with other therapeutic interventions (chemotherapy, radiation, and hyperthermia). |
| 2787 | Computer #68 |
Assessment of radiation damaged mouse lungs using perfluorohexane liquid MRI. |
1Department of Oncology, University of Oxford, Oxford, United Kingdom, 2Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, United Kingdom |
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The imaging of lungs with MRI is difficult owing to low proton density. Imaging with hyperpolarized noble gases has overcome some of these limitations but at great expense and effort. We have investigated damage caused by radiation of mouse lungs using 19F MRI of perfluorohexane – a cheap biocompatible liquid at room temperature. Using lungs filled with perfluorohexane, we were able to obtain high resolution scans with comparable SNRs to hyperpolarized xenon imaging and high resolution. These bright and stable lung images provide a very sensitive tool to monitor the lung damage development. |
| 2788 | Computer #69 |
Monocarboxylate transporter 1 (MCT1) inhibition with AZD3965 leads to MRS-detectable MCT4-dependent blockade of lactate efflux and pyruvate-lactate exchange in human cancer cells providing potential for non-invasive imaging |
1CRUK Cancer Imaging Centre, The Institute of Cancer Research & Royal Marsden NHS Foundation Trust, London, United Kingdom, 2AstraZeneca, Cambridge, United Kingdom |
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The monocarboxylate transporter 1 (MCT1), which mediates the bidirectional movement of molecules such as lactate and pyruvate, is upregulated in cancer and constitutes a promising drug target. Using MRS we investigate the impact of the MCT1 inhibitor AZD3965, currently in phase-I clinical trials, on human cancer cell metabolism to assess potential for pharmacodynamic biomarker discovery. We show that AZD3965 inhibits lactate efflux and blocks hyperpolarised 13C-pyruvate-lactate exchange in human cancer cells in an MCT4-dependent manner. Thus, intracellular lactate and hyperpolarized 13C-pyruvate-lactate exchange are promising metabolic imaging biomarkers for monitoring the action of AZD3965 and potentially other MCT1 inhibitors. |
| 2789 | Computer #70 |
Measuring the effect of CA-IX inhibition on tumor pH in patient-derived xenografts (PDX) of breast cancer. |
1Department of Cancer Imaging and Metabolism, Moffitt Cancer Center, Tampa, FL, United States, 2Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, United States |
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Membrane-bound carbonic anhydrase (CA-IX) plays an important role in maintaining an acidic extracellular pH (pHe) in tumors. We investigate the effect of inhibiting CA-IX on the pHe of patient derived xenografts (PDX) from a triple negative breast cancer using 31P MRS of 3-aminopropylphosphonate (3-APP) as a pH biomarker. Mice were imaged before the injection of the ureido-sulfonamide CA-IX inhibitor (cpd25) and again at 2.5 and 24 hours after injection. There was an increase in pH in 5/6 animals in the first 24 hours. This is first in vivo evidence that CA-IX inhibition disrupts pH in vivo. |
| 2790 | Computer #71 |
Investigation of the mouse colon wall using endoscopic MRI and confocal endomicroscopy |
1CREATIS, Université de Lyon ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Claude Bernard Lyon 1, Villeurbanne, France, 2IGFL, ENS Lyon, Lyon, France, 3LTSI - Inserm U642, Rennes, France, 4CRLCC, Rennes, France, 5Hôpital Régional Universitaire de Tours, Tours, France |
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The purpose of this project is to provide new tools and protocols to evaluate digestive pathologies. To this end, endoscopic MRI, using endoluminal coils, was combined with confocal endomicroscopy (CEM). Both modalities provide complementary information. CEM is well suited to investigate the surface of the colon wall whereas endoscopic MRI can assess deeper structures. It allows characterizing and staging the first steps of cancer development. The study was performed on a mouse model of colitis following 24 animals. This opens perspectives to better understand digestive pathologies such as colorectal cancer and inflammatory bowel disease. |
| 2791 | Computer #72 |
Tissue positional repeatability in head and neck revealed by a dedicated MR simulator: Is positioning verification using bony landmarks adequate in radiotherapy treatment? |
1Medical Physics & Research Department, Hong Kong Sanatorium & Hospital, Hong Kong, China, People's Republic of, 2Department of Radiotherapy, Hong Kong Sanatorium & Hospital, Hong Kong, China, People's Republic of, 3Department of Diagnostic & Interventional Radiology, Hong Kong Sanatorium & Hospital, Hong Kong, China, People's Republic of |
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Current positioning verification in radiotherapy mainly relies on bony structures using X-ray based imaging techniques, where visualization of tumor and soft organ-at-risk is relatively poor. This study aimed to assess the positional repeatability of soft and bony structures, and investigate the correlation between the positional deviations of various head and neck (H&N) tissues. Our results suggested that the current positioning verification practice for radiotherapy relying mainly on bony structure may be inadequate and inefficient in H&N. MR-simulator may play a potential role in improving H&N radiotherapy by enabling positional verification directly on target tissues rather than simply on bony structure. |
| Exhibition Hall | Monday, May 9, 2016: 11:45 - 12:45 |
| 2792 | Computer #73 |
Effects of Temporal Resolution on Quantitative DCE-MRI Prediction of Breast Cancer Therapy Response |
1Oregon Health & Science University, Portland, OR, United States |
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15 breast cancer patients undergoing neoadjuvant chemotherapy (NACT) consented to two DCE-MRI studies at the same time points before, during, and after NACT: one with high temporal resolution (tRes) and the other with low tRes. There were systematic errors in estimated pharmacokinetic (PK) parameters from the low tRes data compared to the high tRes data. However, the abilities of PK parameters for early prediction of pathologic response to NACT were not affected by poorer tRes. |
| 2793 | Computer #74 |
Effect of Neoadjuvant Chemotherapy on in-vivo MRS determined tCho and Membranous and Cytoplasmic b-catenin Expression in Breast Cancer Patients |
1Department of NMR and MRI Facility, All India Institute of Medical Sciences, New Delhi, India, 2Department of Pathology, All India Institute of Medical Sciences, New Delhi, India, 3Department of Surgical Disciplines, All India Institute of Medical Sciences, New Delhi, India |
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We evaluated the changes in tCho levels and β-catenin expression (membrane and cytoplasm) after III neoadjuvant chemotherapy in breast cancer patients. Significant reduction in β-catenin expression (membranous and cytoplasmic) was observed after therapy. Post-therapy, tCho reduced significantly in tumors with Grades 1 and 2 membranous β-catenin expression and also in tumors with IRS 0 and Grade 1 cytoplasmic β-catenin. Prior to therapy, tCho was positively associated with cytoplasmic β-catenin while negatively with membranous protein. However post-therapy tCho was negatively associated with both cytoplasmic and membranous β-catenin. This signifies antiproliferative and apoptosis induction effects of chemotherapy drugs on breast cancer patients. |
| 2794 | Computer #75 |
Correlation of diffusion weighted MR imaging with the prognosis of locally advanced gastric carcinoma to neoadjuvant chemotherapy |
1Radiology, Peking University Cancer Hospital & Institute, Beijing, China, People's Republic of, 2GI surgery, Peking University Cancer Hospital & Institute, Beijing, China, People's Republic of |
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The percentage changes of ADC after neoadjuvant chemotherapy of gastric carcinoma have correlation with long-term prognosis. The significantly increased ADC after chemotherapy is more prone to signify long-term survival, and has potential to be a surrogate imaging biomarker for the prediction of the prognosis. ADCentire for the whole lesion is better than ADCmin for high signal area in the prognosis prediction. |
| 2795
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Computer #76 |
T2*-weighted imaging and DCE-MRI as complementary tools to characterize the continuous process of radionecrosis and neovascularization |
1Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, Sherbrooke, QC, Canada, 2Service of Radiation Oncology, Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada, 3Department of Pharmacology-Physiology, Université de Sherbrooke, Sherbrooke, QC, Canada, 4Department of Pathology, Université de Sherbrooke, Sherbrooke, QC, Canada, 5Department of Diagnostic Radiology, Université de Sherbrooke, Sherbrooke, QC, Canada |
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Radiation dose delivered to healthy tissues during brain tumors radiosurgery can cause important side effects. We imaged an animal model of brain irradiation with DCE-MRI and T2*-weighted imaging at different time points after treatment. DCE-MRI allowed the discrimination of areas with high vessel permeability and necrotic regions. T2*-weighted imaging enabled the visualization of a necrotic core and micro-lesions at its periphery. Micro-lesions were initially co-localized with permeable vessels and later evolved into necrosis. Together, DCE-MRI and T2*-weighted images provided a coherent picture on the phenomena involved in radionecrosis progression, which could help in the management of associated problems. |
| 2796 | Computer #77 |
DIFFUSION-WEIGHTED IMAGING (DWI) AS A TREATMENT RESPONSE BIOMARKER IN PROSTATE CANCER BONE METASTASES |
1The Institute of Cancer Research, Sutton, United Kingdom, 2The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom |
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We hypothesized that changes in the median apparent diffusion coefficient (mADC) and volume of bone metastases (BM), quantified by whole body (WB) diffusion-weighted imaging (DWI), are response biomarkers in metastatic castration-resistant prostate cancer (mCRPC). 21 patients completed WB-DWI at baseline and after 12 weeks of treatment in a sub-study within a clinical trial of olaparib in mCRPC, performed on a 1.5-T Siemens Avanto scanner. Four different segmentation techniques were explored including axial skeleton analyses and simpler methods including 5 target lesions. Changes in mADC and volume of BM associated with response to therapy. The simplified approach also showed promising results, warranting further evaluation. |
| 2797 | Computer #78 |
Response Assessment to Tumor Treating Fields in Patients with Glioblastoma using Physiologic and Metabolic MR Imaging |
1Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States, 2Radiology, University of Miami, Miami, FL, United States, 3Neurosurgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States, 4Neurology, Duke University Medical Center, Durham, NC, United States, 5Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom |
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Tumor treating fields (TTFields) are a novel antimitotic treatment modality for treatment of patients with glioblastoma (GBM). To assess response to TTFields, 4 GBM patients underwent diffusion, perfusion and 3D-echo-planar spectroscopic imaging prior to initiation of TTFields and at one and two month follow-up periods. A trend towards increased MD and a decrease in FA and rCBVmax was noted in most patients at 2-month relative to baseline indicating inhibited tumor growth and vascularity. Cho/Cr values did not exhibit any trend probably due to heterogeneity in response. These preliminary data indicate the potential of advanced MR imaging in assessing response to TTFields. |
| 2798 | Computer #79 |
The value of functional MRI on predicting therapeutic outcome of TACE on hepatocellular carcinoma |
1Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China, People's Republic of |
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The purpose of this study was to explore the efficacy of functional MRI (diffusion-weighted imaging (DWI), IntraVoxel incoherent motion (IVIM) and perfusion-weighted imaging (PWI)) quantitative analysis in predicting therapeutic outcome of TACE on HCC. The Dfast, Ktrans, ΔDfast and ΔKtrans of HCC acquired before and after TACE obviously correlated with PFS and was valuable in the prediction of the clinical outcome of HCC treated with TACE. |
| 2799 | Computer #80 |
Early Assessment of Antiangiogenic Effects of Sorafenib using IVIM in Mouse Model with Hepatocellular Carcinoma |
1GE Healthcare MR Research China, Beijing, China, People's Republic of, 2Radiology, Guangdong General Hospital, Guangzhou, China, People's Republic of |
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Antiangiogenic therapy is efficient to treat hypervascular tumor such as hepatocelluar carcinoma (HCC). Unlike chemotherapy and radiation therapy, tumor dimension doesn’t change in its early phase. Hence traditional reponse criteria based on morphological change fails to early assess the therapeutic response of antiangiogenic treatment. This study used intravoxel incoherent motion (IVIM) theory to separate perfusion and diffusion characteristics in HCC over sereval time points after antiangiogenic Sorafenib administration. It was found that IVIM-derived pure diffusivity and pseudo-diffusivity were able to detect the microvascular collapse and cellular edema in HCC at early phase of antiangiogenic medication. |
| 2800 | Computer #81 |
Lung tumour radiotherapy treatment response assessment using Active Breathing Coordinated (ABC) Diffusion-Weighted Magnetic Resonance Imaging |
1The Institute of Cancer Research and Royal Marsden Hospital, London, United Kingdom, 2The Royal Marsden NHS Foundation Trust, London, United Kingdom, 3Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, London, United Kingdom |
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Imaging with an Active Breathing Coordinator (ABC) modified for MR use was performed on lung cancer patients to acquire spatially matching diffusion-weighted images (DWI) before, during and after Radiotherapy. DWI spatially matched the CT and depicted mediastinal nodal involvement as well as internal tumour heterogeneity. ADC maps provided information about changes in solid and fluid components throughout therapy. Treatment response was evaluated by applying multi-parametric tumour heterogeneity characterisation using Gaussian Mixture Modelling. Differences in ADC and volume behavior of separate cancerous tissue components at various treatment time points may indicate tumour sub-volumes and provide detailed cancer characterisation. |
| 2801 | Computer #82 |
Defining the baseline functional imaging characteristics of retroperitoneal sarcomas |
1MRI, Royal Marsden Hospital, Sutton, United Kingdom, 2Division of Radiotherapy and Imaging, Cancer Research UK Cancer Imaging Centre, Institute of Cancer Research, London, United Kingdom, 3Department of Radiotherapy, Royal Marsden Hospital, London, United Kingdom, 4Department of Surgery, Royal Marsden Hospital, London, United Kingdom, 5Department of Histopathology, Royal Marsden Hospital, London, United Kingdom |
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Soft tissue sarcomas are often highly heterogeneous tumours and post-treatment changes cannot be described by standard size criteria. Functional imaging may provide a non-invasive method of assessing response to treatment. Knowledge of baseline functional imaging characteristics and the repeatability of estimated parameters is essential in development of future studies. In this study, 22 patients with retroperitoneal sarcoma were imaged before treatment. Whole-tumour assessments of apparent diffusion coefficient (ADC), parameters of the intra-voxel incoherent motion model (IVIM: diffusion coefficient D, fraction f, fast exponential component D*), transverse relaxation rate (R2*), fat fraction and enhancing fraction (EF) showed large ranges of median estimates, indicating wide inter-tumour heterogeneity. The large standard deviation of parameters within tumours reflects the intra-tumour heterogeneity. In 21 patients, a second examination was carried out to assess repeatability of ADC, D, f, D* and R2*. Excellent repeatability of fitted parameters, particularly ADC, indicates high sensitivity to treatment-induced changes. |
| 2802 | Computer #83 |
Gaussian mixture modelling of combined functional imaging parameters provides new insight into tumour heterogeneity |
1MRI, Royal Marsden Hospital, Sutton, United Kingdom, 2Division of Radiotherapy and Imaging, Cancer Research UK Cancer Imaging Centre, Institute of Cancer Research, London, United Kingdom, 3Department of Radiotherapy, Royal Marsden Hospital, London, United Kingdom, 4Department of Surgery, Royal Marsden Hospital, London, United Kingdom, 5Department of Histopathology, Royal Marsden Hospital, London, United Kingdom |
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Multi-parametric functional imaging may enable non-invasive assessment of response to treatment in soft tissue sarcomas. Image analysis is complicated, however, by the highly heterogeneous nature of these tumours, which can include regions of cellular tumour, fat, necrosis and cystic change that may respond differently to treatment. In this study, patients with retroperitoneal sarcoma were imaged before and after radiotherapy using DW-MRI, Dixon and pre-/post-contrast T1-w imaging for evaluation of enhancing fraction (EF). Gaussian mixture modelling was applied to classify pixels in the tumour volume according to their functional imaging behaviour, combining ADC, fat fraction and EF to characterise tumour components. This method enabled segmentation of highly heterogeneous tumours and estimation of mean ADC and volume of each tumour component. Heterogeneous changes post-radiotherapy were summarised in tissue classification maps, which combine multiple functional imaging parameters. Combined analysis of functional imaging parameters may provide greater insight into tumour behaviour, for example identification of viable tumour. |
| 2803 | Computer #84 |
Threshold functional imaging maps depict intra-tumour heterogeneity of response to radiotherapy in retroperitoneal sarcomas |
1MRI, Royal Marsden Hospital, Sutton, United Kingdom, 2Division of Radiotherapy and Imaging, Cancer Research UK Cancer Imaging Centre, Institute of Cancer Research, London, United Kingdom, 3Department of Radiotherapy, Royal Marsden Hospital, London, United Kingdom, 4Department of Surgery, Royal Marsden Hospital, London, United Kingdom, 5Department of Histopathology, Royal Marsden Hospital, London, United Kingdom, 6Department of Clinical Oncology, Royal Marsden Hospital, London, United Kingdom |
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Functional imaging provides scope for non-invasive assessment of response to radiotherapy and/or systemic agents in retroperitoneal sarcomas and investigation of heterogeneity of response in this highly heterogeneous tumour type. In this study 9 patients with retroperitoneal sarcoma were imaged before treatment and 2-4 weeks after radiotherapy. Whilst some tumours exhibited large increases in median ADC and enhancing fraction after radiotherapy, the overall changes for the cohort were not significant and there were no clear changes in fat fraction. Thresholded ADC maps and enhancement maps, however, reveal localised post-radiotherapy changes in ADC and enhancement that are not fully characterised by whole-tumour metrics. |
| 2804 | Computer #85 |
Chemical exchange saturation transfer (CEST) and relaxometry as biomarkers for assessing response of brain metastases to stereotactic radiosurgery |
1Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada, 2Medical Biophysics, University of Toronto, Toronto, ON, Canada, 3Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, Canada, 4Radiation Oncology, Odette Cancer Centre, Toronto, ON, Canada |
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Quantitative MRI techniques that probe the metabolic and micro-structural changes in the tumor have the potential to assess response of brain metastases to stereotactic radiosurgery early after treatment. Two techniques were investigated here: a) Chemical Exchange Saturation Transfer (CEST), b) Relaxometry. Among all model parameters, early changes in the intracellular-extracellular water exchange rate in relaxometry, and peak amplitude of nuclear overhauser effect at the ipsilateral normal appearing white matter in CEST provided the strongest correlation with tumor volume change one-month post-treatment. We also demonstrated that these two parameters were highly correlated suggesting they could provide complementary information about treatment effects. |
| 2805 | Computer #86 |
MRI in Assessing Response to Neoadjuvant Chemo-radiation in Locally Advanced Rectal Cancer Using DCE-MR and DWI Data Sets: Before, During and After the Treatment |
1Radiation Oncology, Rutgers-Cancer Institute of New Jersey, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, United States, 2Radiation Oncology, Sir Run Run Shaw Hospital, Zhejiang University of Medicine, Hangzhou, China, People's Republic of, 3Institute of Translational Medicine, Hangzhou, China, People's Republic of, 4Radiology, Sir Run Run Shaw Hospital, Zhejiang University of Medicine, Hangzhou, China, People's Republic of |
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We are one of the first to investigate the predictive value of combined anatomical, DCE-MRI and DWI for good pathological response at different time points during the pre-operative chemo-radiation treatment (CRT) in patients with locally advanced rectal cancer (LARC). The pre-treatment ADC and internal heterogeneity enhancement measured by texture features from DCE-MRI and the relative change of the ADC values during the treatment showed good prognostic value with pathological response. Overall, this study provides new information of the optimal use of MRI in predicting response to the pre-operative CRT, which may further help tailor the treatment into the era of personalized medicine. |
| 2806 | Computer #87 |
Altered lipid metabolism on 1H NMR as response biomarkers in prostate cancer cells and tumors following radiotherapy |
1Medical Imaging and Intervention, Chang Gung Memorial Hospital, Taoyuan, Taiwan, 2Radiation Oncology, Chang Gung Memorial Hospital, Taoyuan, Taiwan |
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The intracellular storage and utilization of lipids are critical for cancer cells to maintain energy homeostasis. In this study, we investigated the changes of lipid metabolites in murine TRAMP-C prostate cancer cells and tumors following radiotherapy. The lipid profile following radiotherapy demonstrated increased levels of fatty acids and triacylglycerols, before the change of tumor size. The increase of lipids signals can potentially serve as early response biomakers in clinical setting for prostate cancer patients following radiotherapy. |
| 2807 | Computer #88 |
Impact of T1 and B1 correction on quantitative DCE-MRI for assessing longitudinal therapy response in breast cancer |
1GE Global Research, Bangalore, India, 2University of Cambridge, Cambridge, United Kingdom, 3GE Global Research, Niskayuna, NY, United States, 4GE Healthcare, Leeds, United Kingdom |
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In this work, we investigated the impact of incorporating T1 and/or B1 maps on PK parameters in breast cancer patients and impact of these PK maps on assessing therapy response in longitudinal data. DCE-MRI PK parameters in six breast cancer patients was investigated with four different processing schemes comprising combinations of T1 and B1 map with DCE and its trend assessed in longitudinal data . We demonstrate that in breast tumor imaging, a DCE protocol incorporating T1 and B1 mapping can be more reliable in reflecting tumor heterogeneity and predicting therapy response longitudinally. |
| 2808 | Computer #89 |
Monitoring Breast Cancer Response to Neoadjuvant Chemotherapy by Diffusion Tensor Imaging |
1Department of Biological Services, The Weizmann Institute of Science, Rehovot, Israel, 2Department of Biological Regulation, The Weizmann Institute of Science, Rehovot, Israel, 3Radiology, Hospital de la Ribera, Alzira, Spain |
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We have evaluated the ability of diffusion tensor imaging (DTI) to assess breast cancer response to neoadjuvant chemotherapy. Changes in lesion size and diffusion parameters in response to therapy were determined. Diameter and volume measurement derived from DTI were compared to those derived from dynamic contrast enhanced (DCE) MRI and to post surgery pathological reports. A high congruence was found between DTI and DCE-MRI for tumor size and response evaluation, with both methods showing a good agreement with pathology results. |
| 2809 | Computer #90 |
Evaluation of neoadjuvant chemotherapy combined with bevacizumab in breast cancer using MR metabolomics |
1Department of Circulation and Medical Imaging, The Norwegian University of Science and Technology, Trondheim, Norway, 2K.G. Jebsen Center for Breast Cancer Research, Institute of Clinical Medicine, University of Oslo, Oslo, Norway, 3Institute for Molecules and Materials, Radboud University Nijmegen, Nijmegen, Netherlands, 4Department of Genetics, Institute for Cancer Research, Oslo University Hospital, The Norwegian Radium Hospital, Oslo, Norway, 5NERC Biomolecular Analysis Facility Metabolomics Node (NBAF-B), School of Biosciences, University of Birmingham, Birmingham, United Kingdom, 6Department of Oncology, Department of Tumor Biology, Oslo University Hospital, Oslo, Norway |
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This study used HR MAS magnetic resonance based metabolic profiles from breast tumor tissue to explore the metabolic changes occurring as an effect of overall neoadjuvant therapy, discriminate therapy responders from nonresponders, and determine metabolic differences between patients receiving or not receiving the antiangiogenic drug bevacizumab. Changes as an effect of chemotherapy were detected and responders were successfully discriminated from nonresponders after treatment, showing potential for assessment of patient benefit to treatment and the understanding of underlying mechanisms affecting response. Although metabolic differences based on bevacizumab administration were not prominent, glutathione was identified to be possibly affected by the drug. |
| 2810 | Computer #91 |
Early detection of changes in phospholipid metabolism during neoadjuvant chemotherapy using phosphorus magnetic resonance spectroscopy at 7 tesla |
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Medical Oncology, Academic Medical Center Amsterdam, Amsterdam, Netherlands |
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Neoadjuvant chemotherapy plays an important role in the treatment of breast cancer patients. During chemotherapy, the phospholipid metabolism changes which can be measured by 31P-MRS at 7 tesla. Eight patients were examined, using the AMESING sequence to receive metabolic signals in the tumor. The 31P-MRS data were analyzed on group level, which enables the detection of changes the levels of phospholipid metabolites in an early stage of the treatment, directly after the first cycle of chemotherapy. |
| 2811 | Computer #92 |
The Role of Heterogeneity Analysis for Differential Diagnosis in Diffusion-Weighted Images of Meningioma Brain Tumors |
1Quantitative MR Imaging and Spectroscopy Group (QMISG), Research Center for Molecular and Cellular Imaging (RCMCI), Tehran University of Medical Sciences, Tehran, Iran, 2Department of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran, 3Radiology Department, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran, 4Department of Mathematics, Islamic Azad University, Qazvin Branch, Qazvin, Iran |
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Meningioma brain tumors constitute the majority of adult primary brain tumors, in which the role of apparent diffusion coefficient (ADC) is controversial. We hypothesize that analysis of the heterogeneity within a tumorous ecological region can reveal biological tissue properties, which could further assist decision making about the optimum patient-specific treatment strategy. In the present work, we propose an automated computer-aided diagnosis method for phenotyping meningioma brain tumors, based on features representing spatial heterogeneity in ADC-maps, with classification accuracy of 85.1%. In conclusion, it is demonstrated that heterogeneity of meningioma brain tumors can be a potential discriminating biomarker of tumor malignancy. |
| 2812 | Computer #93 |
Microvascular Heterogeneity Assessed Using DCE-MRI Predicts Disease-Free Survival in Cancers of the Cervix, Bladder, and Head and Neck |
1Institute of Cancer Sciences, The University of Manchester, Manchester, United Kingdom, 2Christie Medical Physics and Engineering, Christie NHS Foundation Trust, Manchester, United Kingdom, 3Diagnostic Radiology, Christie NHS Foundation Trust, Manchester, United Kingdom, 4Centre for Imaging Sciences, The University of Manchester, Manchester, United Kingdom |
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There is a clinical need for non-invasive imaging biomarkers capable of accurately predicting outcomes in locally advanced cancers. Microvascular heterogeneity measurements obtained from dynamic contrast enhanced-MRI have shown prognostic utility however no attempt has been made to compare the prognostic value of the available methods across disease and identify which type of heterogeneity (statistical or spatial) is important for survival. In this study we identify heterogeneity biomarkers that are universally prognostic across cancers of the cervix, bladder, and head and neck and compare their prognostic value to standard clinicopathologic factors such as disease stage. |
| 2813 | Computer #94 |
Oscillatory shear strain impacts metastatic cancer cell spread |
1Biomedical Engineering, King's College London, London, United Kingdom, 2Imaging Chemistry and Biology, King's College London, London, United Kingdom, 3London, United Kingdom, 4Imaging Chemistry and Biology, King's College London, Lodnon, United Kingdom |
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Major reasons of cancer related deaths are repercussion of the dissemination of cancer cells from the primary tumour site and an outgrowth at the secondary metastatic site. The microenvironment where the cancer cells reside with various signals, are central factors to provide cancer cell spread throughout the body; signals can be (bio)chemical or mechanical nature. Translation of mechanical forces, displacements and deformations into biochemical signals (i.e. mechanotransduction) affects their adhesion, spread and survival. We show here, that focussed shear waves operating at specific frequency and amplitude affects the metastatic behaviour of cancer cells by reducing the invasive behaviour and growth. |
| 2814 | Computer #95 |
Can Diffusion Weighted MRI Assess Early Response of Lymphadenopathy to Induction Chemotherapy in Nasopharyngeal Cancer: A Heterogeneity Analysis Approach |
1, Tehran University of Medical Sciences, Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Institute for Advanced Medical Imaging, Tehran, Iran, 2Tehran University of Medical Sciences, Quantitative MR Imaging and Spectroscopy Group, Research Center for Cellular and Molecular Imaging, Institute for Advanced Medical Imaging, Tehran, Iran, 3Statistics, Shiraz University of Medical Science, Shiraz, Iran, 4Jorjani Radiotherapy Center, Shahid Beheshti of Medical Sciense, Tehran, Iran, 5Shahid Beheshti University of Medical Science, Tehran, Iran, 6Payambaran MRI center, Tehran, Iran |
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Induction chemotherapy is an effective way to control subclinical metastasis in locally-advanced nasopharyngeal cancer patients. Diffusion-weighted MRI is a noninvasive imaging technique allowing some degree of tissue characterization by showing and quantifying molecular diffusion. Histogram analysis on ADC map could be carried out to reveal physiological alterations early after IC. For this purpose, several quantitative metrics from ADC-map were explored to obtain the most accurate feature(s) as potential predictive biomarker for early response of the lymphnode to IC. If the outcome can be predicted at an early stage of the treatment, the patient could be spared from unnecessary treatment toxicity. |
| 2815 | Computer #96 |
Monitoring Changes of the Tumor Microenvironment Following Administration of a Novel Vascular Disrupting Agent OXi6197 Using Multi-parametric MRI |
1Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 2Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, United States, 3Chemistry and Biochemistry, Baylor University, Waco, TX, United States |
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Vascular disrupting agents (VDAs), selectively damage the endothelial cells of tumor blood vessels, inducing ischemia and consequent hypoxia and cell death. We investigated the impact of a novel indole-based VDA (OXi6197) to tumor perfusion and oxygenation using multi-parametric MRI on a lung tumor animal model. DCE MRI showed decreased blood flow after administration of VDA. Oxygen sensitive MRI, BOLD and TOLD, showed progression of hypoxia at 24 hours. Multimodality imaging provides useful information to evaluate the efficacy of VDA. The findings in this study will be important for dose optimization and potential combination therapy in the future. |
| Exhibition Hall | Monday, May 9, 2016: 14:15 - 15:15 |
| 2816 | Computer #1 |
trueFLASH: Model-Based Iterative T1 Mapping using Variable-Flip-Angle Fast Low-Angle Shot |
1Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG, Lausanne, Switzerland, 2Department of Radiology, University Hospital (CHUV), Lausanne, Switzerland, 3LTS5, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 4Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland, 5Department of Biomedical Engineering, University of Basel, Basel, Switzerland, 6Siemens Medical Solutions USA, Inc., Boston, MA, United States |
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Various methods have been published to quantify the longitudinal relaxation T1; amongst others, a variable-flip-angle fast low-angle shot acquisition can be used. Here, we suggest applying an 8-fold undersampling to such an acquisition, subsequently using a model-based iterative optimization to estimate T1 maps. This approach allows the acquisition of whole-brain 1.3mm isotropic T1 maps within 3:20min using 16 different flip angles. Aliasing artifacts due to the undersampling were successfully removed by the iterative reconstruction. However, the T1 maps show a slight overestimation of T1 values and require a B1-field correction as it is typical for variable-flip-angle approaches. |
| 2817 | Computer #2 |
Fast 3D Acquisition for Quantitative Mapping and Synthetic Contrasts Using MIRACLE and trueCISS |
1Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG, Lausanne, Switzerland, 2Department of Radiology, University Hospital (CHUV), Lausanne, Switzerland, 3LTS5, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 4Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland, 5Department of Biomedical Engineering, University of Basel, Basel, Switzerland, 6Siemens Medical Solutions USA, Inc., Boston, MA, United States |
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Quantitative imaging promises to be a good biomarker of disease but requires long acquisition times, especially when 3D acquisition techniques are used. Here we propose to use a highly undersampled 3D phase-cycled balanced steady-state free-precession sequence in combination with the reconstruction methods MIRACLE and trueCISS, providing quantitative maps (T2,T1,M0). Additionally, synthetic contrasts can be generated using the previously calculated quantitative maps and signal models, exemplarily shown for bSSFP, T2- and T1-weighted contrast. In summary, the proposed method provides a set of quantitative maps and various conventional contrasts using a single 3:31min acquisition. |
| 2818 | Computer #3 |
Rapid Multislice T1 Mapping of Contrast-Enhanced Mouse Tumor Using Saturation Recovery Look-Locker Method with Spiral Readout |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, United States, 3Radiology, Case Western Reserve University, Cleveland, OH, United States, 4Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, United States, 5Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States |
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In this study, a rapid multislice saturation-recovery Look-Locker (MSRLL) T1 mapping method with spiral readout was developed for the application on tissues with long T1 value, such as tumor. This method was validated in vitro and evaluated in a dynamic contrast-enhanced MRI (DCE-MRI) study on mouse tumor. The spiral MSRLL method showed a strong agreement with Cartesian method, and achieved temporal resolution of 2 min 40s with a voxel size of 0.23×0.23×1 mm3 in vivo. |
| 2819 | Computer #4 |
Comparison of Signal intensity measures with absolute T1 value quantification in patients undergoing serial follow up imaging in patients with neurocysticercosis |
1Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, India, 2Healthcare, Philips India ltd, Bangalore, India, 3Department of Neurology, KG Medical University, Lucknow, India, 4Healthcare, Philips India ltd, Gurgaon, India |
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Gadolinium based contrast agents are necessary for MRI for disease detection and therapy. Studies reported gadolinium remains in brain for long time after injecting contrast particularly in follow up patients undergoing serial contrast applications. T1 signal intensity increases slowly due to contrast accumulation in brain. Our study quantifies T1 relaxation time as a measure for follow up contrast patients. Results show absolute T1 significantly decreases in Gray Matter regions, putamen, thalamus and globus pallidus. We conclude that absolute T1 quantification can efficiently pick up deposition of gadolinium much earlier than T1 signal intensity changes as observed in Gray matter regions. |
| 2820 | Computer #5 |
NOVIFAST: A fast non-linear least squares method for accurate and precise estimation of T1 from SPGR signals |
1University of Antwerp, Antwerp, Belgium, 2Delft University of Technology, Delft, Netherlands, 3Uppsala University, Uppsala, Sweden |
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The longitudinal relaxation time T1 can be estimated from a set of spoiled gradient recalled echo (SPGR) magnetic resonance images acquired over a range of flip angles with constant repetition time (TR). While linear estimators are widely used because of their low computation time, they are less accurate than their slower nonlinear counterpart1. In this work, we introduce a novel NOn-linear VarIable Flip Angle data baSed T1 (NOVIFAST) estimator that combines the best of both worlds: high accuracy and precision in a low computation time. |
| 2821 | Computer #6 |
The effect of through-plane gradients on 2D gradient-echo acquisitions: are sinc-term corrections appropriate for R2* mapping? |
1Department of Radiology, Boston Children's Hospital, Boston, MA, United States, 2Harvard Medical School, Boston, MA, United States |
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We made slice profile measurements and acquired 2D multi-gradient-echo data on a phantom in the presence of various through-plane gradients. The sinc-term correction for R2* mapping that is commonly used to compensate for the dephasing effects of these gradients was substantially outperformed by a correction based on the measured slice profiles. Our results highlight the importance of incorporating realistic slice profiles into the estimation of “intrinsic” R2* values, which may contain information about tissue structure at microscopic-to-mesoscopic spatial scales. |
| 2822 | Computer #7 |
Molecular Mechanism of Transverse Relaxation in Whole Blood with Plasma Contrast Reagent: Simulations of Bulk Magnetic Susceptibility and Water Exchange |
1University of Washington, Seattle, WA, United States, 2Oregon Health and Science University, Portland, OR, United States, 3Puget Sound VA HCS, Seattle, WA, United States |
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Previously reported T2* values in oxygenated whole blood with gadolinium based contrast reagents are very small. This has important implications for optimization of contrast-enhanced MR angiography and quantification of arterial input functions. To investigate the molecular mechanism of these short T2* values, we have performed Monte Carlo simulations of signal dephasing that predict the reported values remarkably well. Intracellular water signal experiences a frequency shift that is dependent on the orientation of the RBC in the magnetic field. The resulting frequency distribution in combination with trans-membrane water exchange results in rapid dephasing of water signal. |
| 2823 | Computer #8 |
Relaxation Properties of Human Umbilical Cord Blood at 1.5 Tesla |
1Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2Department of Obstetrics and Gynaecology, University of Toronto, Toronto, ON, Canada, 3Institute of Medical Science, University of Toronto, Toronto, ON, Canada, 4Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, Canada, 5Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON, Canada |
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Relaxometry measurements were performed on umbilical cord blood samples (N=88) spanning a broad range of hematocrits (0.19<Hct<0.76) and oxygen saturations (4%<sO2<100%). Simple biophysical models were used to describe variations in T1 and T2 as a function of these blood properties. The data and fitted model parameters presented here can be used for calibration of future MRI investigations of fetal and neonatal blood physiology. |
| 2824 | Computer #9 |
Quantitative T2 mapping using a modified BIR-4 T2 preparation in the presence of large B0 offsets |
1Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, 2Philips Healthcare, Hamburg, Germany, 3Philips Research Laboratory, Hamburg, Germany, 4Section of Neuroradiology, Technische Universität München, Munich, Germany, 5Zentralinstitut für Medizintechnik, Technische Universität München, Garching, Germany |
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T2 mapping has been emerging as a tool to quantitatively assess tissue edema and inflammation. Sequences employing T2 preparation have been suggested for accurate and precise T2 quantification. The use of the modified BIR-4 pulse has been proposed to minimize the sensitivity of T2 mapping to B1 inhomogeneities. However, in the presence of large B0 offsets, part of the magnetization can experience both T1 and T2 relaxation during the BIR-4 pulse leading to T2 quantification errors. The present work proposes a novel methodology to make T2 quantification based on the modified BIR-4 robust to the presence of large B0 offsets. |
| 2825 | Computer #10 |
Contrast optimization using Fast Field Cycling techniques and fast low angle sequences |
1IR4M (Imagerie par Résonance Magnétique Médicale et Multi-modalités), Univ. Paris-Sud, CNRS, UMR8081, Université Paris-Saclay, Orsay, France |
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Fast Field Cycling MRI offers the possibility to explore new contrasts generated from NMR dispersion (NMRD) profiles of tissue or contrast agents. Here, it is shown that dreMR contrast can be generated and optimized in fast low flip angle sequences extending the range of sequences that can be used with this new degree of freedom. The expression of a generalized Ernst angle maximizing signal with dreMR pulses is derived as well as the angle maximizing the dispersive contrast. |
| 2826 | Computer #11 |
Whole brain adiabatic T1rho and Relaxation Along a Fictitious Field imaging in healthy volunteers: feasibility and initial findings |
1University of Turku, Turku, Finland, 2A.I. Virtanen Institute for Molecular Sciences, Kuopio, Finland |
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The adiabatic T1ρ and RAFF measurements, RAFF2 and RAFF4, were performed in 28 healthy volunteers (24-69 years) and four of them had repeated MR scan within 4 weeks to evaluate short term repeatability. The relative differences on the voxel level were below 5% in gray and white matter for all of the relaxation parameters except of TRAFF4 in gray matter which was 7.3%. No statistically significant age related changes in white and gray matter were present as evaluated by adiabatic T1ρ, RAFF2 and RAFF4 imaging. |
| 2827 | Computer #12 |
T1ρ dispersion in human calf muscle |
1Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, 2Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 3Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, United States |
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T1ρ imaging is sensitive to slow macromolecular interactions which may be generally characterized by a correlation time (τc) but also varies with the strength of the locking field used (ω1). At higher fields (3T and beyond) T1ρ is also strongly influenced by chemical exchange processes and the dispersion of the relaxation rate R1ρ (=1/T1ρ) with locking field may be used to quantify exchange processes. We imaged normal muscles from individuals of different ages and found that R1ρ value is negatively correlated with age in normal muscle, and there is a small dispersion of R1ρ that appears to increase with age. |
| 2828 | Computer #13 |
Evaluation of Renal Oxygenation using a Simultaneous Dynamic R2, R2' and R2* Quantification Approach – Under the Influence of Hyperoxic Challenge |
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China, People's Republic of, 2College of Engineering, Peking University, Beijing, China, People's Republic of, 3Philips Healthcare, Suzhou, China, People's Republic of, 4Department of Radiology, Peking University First Hospital, Beijing, China, People's Republic of |
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This study demonstrates the feasibility of dynamic renal R2, R2’ and R2* measurement with the proposed psMASE-ME method. High temporal resolution was achieved by combining psMASE sequence and moving estimation strategy. The superiorities of this method could potentially be used in the renal oxygenation evaluation. |
| 2829 | Computer #14 |
Highly Accelerated, Intravascular T1, T2, and Proton Density Mapping with Linear Algebraic Modeling and Sensitivity Profile Correction at 3T |
1Dept. of Electrical & Computer Engineering, Johns Hopkins University, Baltimore, MD, United States, 2Russell H. Morgan Dept. of Radiology & Radiological Sciences, Johns Hopkins University, Baltimore, MD, United States, 3(currently) Philips Innovation Campus, Bangalore, India |
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Vessel wall MRI with intravascular (IV) detectors can produce superior local signal-to-noise ratios (SNR) and generate high-resolution T1, T2, and proton density (PD) maps that could be used to automatically classify atherosclerotic lesion stage. However, long acquisition times potentially limit multi-parametric mapping. Here, for the first time, spectroscopy with linear algebraic modeling (SLAM) is applied to yield accurate compartment-average T1, T2 and PD measures at least 10 times faster compared to a standard full k-space reconstructed MIX-TSE sequence at 3T. Simple phase and magnitude sensitivity corrections are incorporated into the SLAM reconstruction to compensate for IV detector non-uniformity. |
| 2830 | Computer #15 |
A Pulse Sequence for T1rho Imaging of Liver in Human Subjects |
1Imaging and Interventional Radiology, the Chinese University of Hong Kong, New Territory, Hong Kong, 2Philips Healthcare, New Territory, Hong Kong |
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T1rho is a potential biomarker for evaluation of liver fibrosis. However, the application of T1rho imaging for liver disease in human subjects remains challenging. We propose a pulse sequence based on single shot Turbo (Fast) Spin Echo (SSTSE or SSFSE) acquisitions to address the problems. |
| 2831 | Computer #16 |
Fast Fluid Suppressed T1ρ Imaging of the Human Brain |
1German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany, 2University of Bonn, Department of Physics and Astronomy, Bonn, Germany |
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The longitudinal relaxation time in the rotating frame (T1ρ) is a non-invasive biomarker, which is sensitive to slow macromolecular interactions. It might potentially be useful to detect pathological changes in neurodegenerative diseases such as Alzheimer’sDisease. However, long scan times and high SAR limit the application of this technique in a routine setting. Furthermore, high CSF signal modulates the image intensity at CSF/tissue boundaries leading to an overestimation of T1ρ in these regions. To overcome these issues we developed a fast and robust approach to assess T1ρ in the human brain at high image resolution. |
| 2832 | Computer #17 |
Colloidal Nanoparticles for MRI Contrast Agents |
1UMRAM-National Magnetic Resonance Research Center, Bilkent University, Ankara, Turkey, 2Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey, 3UNAM – Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, Turkey, 4School of Mathematical and Physical Sciences, Nanyang Technological University, Singapore, Singapore, 5Department of Molecular Biology and Genetics, Bilkent University, Ankara, Turkey |
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Magnetic resonance imaging (MRI) contrast agents, employed as image contrast enhancement mechanism, are able to change either negative or positive signal intensity. T2 contrast normally offers magnetic susceptibility artifacts and decreases the resolution. On the other hand, T1 contrast provides high spatial resolution, but it suffers from the deficiency of high contrast-to-noise ratio, which limits their clinical applications. To overcome the aforementioned limitations, we offer cubic shape super-paramagnetic iron oxide nanoparticles (SPIONs) as dual-mode colloidal MRI contrast agents. The in vitro and in vivo T1 and T2 MR images promise the great potential clinical application of SPIO nanocubes as dual-mode MR contrast agent. |
| 2833 | Computer #18 |
Quantifying Chemical Exchange Contributions in Mixtures Using Spin-Lock MRI |
1Physics and Astronomy, Vanderbilt University, Nashville, TN, United States, 2Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 3Radiology, Vanderbilt University, Nashville, TN, United States, 4Biomedical Engineering, Vanderbilt University, Nashville, TN, United States |
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R1ρ dispersion provides insight into the rates of molecular processes that give rise to relaxation, and a technique called Exchange Rate Contrast (ERC) can differentiate proton pools based on chemical exchange rates. Double dispersion phenomena may occur when three exchanging proton pools are present, and parametric images may be calculated in which the image intensity scales with the concentration of the exchanging pools. A theoretical equation was derived for this contrast and shown to align well with Bloch-McConnell simulations. Various applications with exogenous contrast agents present a great deal of potential for utilizing this technique in practice. |
| 2834 | Computer #19 |
Paradoxical Narrowing of the Spectroscopy Water Peak in the Presence of Iron Overload |
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 3Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 4Medicine, University of Wisconsin-Madison, Madison, WI, United States, 5Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States |
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In phantoms with large iron particles, as well as in patients with liver iron overload, a paradoxical relationship was observed where the linewidth measured from MRS was smaller than the linewidth obtained from multi-echo spoiled gradient echo MRI. Assuming a model of “apparent” R2 decay in the presence of iron where single-echo acquisitions are essentially diffusion-weighted by the iron-induced B0 heterogeneities, we speculate that different isochromats within the observed spectra undergo different diffusion weighting related to their location relative to nearby large iron particles. These observations may have implications for the characterization of iron deposition in tissue. |
| 2835 | Computer #20 |
Towards Optimized Experiment Design for Magnetic Resonance Fingerprinting |
1Martinos Center for Biomedical Imaging, Chalestown, MA, United States, 2Signal and Image Processing Institute, University of Southern California, Los Angeles, CA, United States |
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A principled framework is proposed to optimize the experiment design for magnetic resonance fingerprinting (MRF) based on the Cramer-Rao bound. Within this framework, we optimize the acquisition parameters (flip angle, TR, etc.) to maximize the SNR efficiency of quantitative parameter estimation. Preliminary results indicate that the optimized experiments allow for substantially reducing the length of an MRF acquisition and substantially improving estimation performance for the T2 map, while maintaining similar accuracy level for the T1 map. The proposed framework should prove useful for fast quantitative MR imaging with MRF. |
| 2836 | Computer #21 |
Myelin Water Imaging using 3D Radial multi-echo GRE acquisition |
1School of Electrical and Electronic Engineering, Yonsei University, Soeul, Korea, Republic of, 2Department of Radiology, Seoul St. Mary Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea, Republic of |
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Recently, myelin water fraction was investigated using multi-echo GRE data. In case of complex model fitting for MWF, only a small fraction of the total signal is used, small artifacts caused by physiological motion can induce severe noise in MWF. To overcome this problem, radial trajectory which is known to have robustness against object motion can be used. Also, this trajectory has the additional advantage of acquiring the more center of k-space than Cartesian trajectory which is helpful for detecting accurate T2* decay curve, and it may provide higher SNR and improved quantification. In this abstract, we demonstrated that the radial acquisition can reduce artifacts and improve image quality in MWF. |
| 2837 | Computer #22 |
Myelin Water Imaging in Multiple Sclerosis Post-Mortem Spinal Cord |
1Neuroscience and Trauma, Queen Mary University of London, London, United Kingdom, 2University of British Columbia, Division of Neurology, Department of Medicine, Vancouver, BC, Canada, 3Neuroimaging Analysis Centre, Department of Brain Repair and Rehabilitation, London, United Kingdom, 4Clinical Physics, Barts Health Trust, London, United Kingdom, 5Department of Neurology, Barts Health Trust, London, United Kingdom |
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Evidence obtained from post mortem multiple sclerosis (MS) brain suggest that ‘myelin water fraction’ (MWF) acquired using the CPMG sequence is strongly associated with myelin. However, relaxation times differ significantly between brain and spinal cord (SC), a key area of the clinical manifestations of MS. We investigated the histological correlates of MWF in post mortem MSSC. Good separation of the short T2 components, and correlation between MWF and myelin content detected using immunohistochemistry were observed. |
| 2838 | Computer #23 |
Linear models for estimating myelin and iron content in the brain |
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany |
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Quantitative MRI maps are believed to strongly correlate with myelin and and ferritin content. Recently, a model combining prior information from non-MRI quantitative techniques was proposed for the quantification of myelin and ferritin based on relaxometry information $$$R_1$$$ and $$$R_2^*$$$ in post mortem human brain samples. Here, we propose four different simple linear models for tentatively obtaining semi-quantitative information using simultaneous quantitative acquisitions under in vivo conditions. Three of the four model are relatively consistent, but do not agree with previously published measurements. A fourth model, although not validated, is compatible with previous works.
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| 2839 | Computer #24 |
Inter-scanner reproducibility of 4 minute whole brain myelin mapping using FAST-T2 |
1Weill Cornell Medical College, New York, NY, United States |
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The purpose of this study was to measure the inter-scanner reproducibility of fast myelin water fraction (MWF) mapping using a 4 min FAST-T2 sequence on three scanners from two vendors at 1.5T and 3T. Regional MWF measurements obtained in 7 healthy volunteers were highly reproducible with excellent inter-scanner correlation (R>0.95) and small MWF bias of less than 1%. |
| Exhibition Hall | Monday, May 9, 2016: 14:15 - 15:15 |
| 2840 | Computer #25 |
Absolute quantification of white matter lesion iron and myelin using QSM and FAST-T2 at 3 Tesla |
1Weill Cornell Medical College, New York, NY, United States |
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The purpose of this study was to develop a clinically feasible method for quantifying myelin and iron distribution in white matter lesions by integrating absolute myelin water mapping using Fast Acquisition using Spiral Trajectory and T2prep (FAST-T2) sequence with Quantitative Susceptibility Mapping (QSM). Preliminary results from 8 healthy volunteers and 3 MS patients demonstrated the feasibility of the developed method. |
| 2841 | Computer #26 |
Susceptibility Changes in Dentate Nucleus on Quantitative Susceptibility Mapping due to serial GBCAs administration. |
1Radiology, Graduate school of Medicine, Kyoto University, Kyoto, Japan, 2Human Brain Research Center, Graduate school of Mediine, Kyoto University, Kyoto, Japan |
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Gadolinium-based contrast agents (GBCAs) have been widely used for contrast material-enhanced magnetic resonance (MR) imaging. However, gadolinium accumulation in the dentate nucleus (DN) has gained attention due to recent studies. In this study, we retrospectively evaluated the susceptibility values of DN, using quantitative susceptibility mapping. The susceptibility values of the patients with GBCA administration were significantly higher than those of normal controls. |
| 2842 | Computer #27 |
The Absence of Phase Information in the Signal-Deprived Image Background is an Important Source of Error in Susceptibility Mapping |
1Center for In Vivo Microscopy, Duke University, Durham, NC, United States, 2Biomedical Engineering, Duke University, Durham, NC, United States, 3Brain Imaging & Analysis Center, Duke University, Durham, NC, United States, 4Radiology, Duke University, Durham, NC, United States |
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Susceptibility mapping is limited in part due to reconstruction artifacts spawning from errors in tissue frequency data. Through simulations of susceptibility tensor imaging (STI) data, we show that a lack of phase information in the image background (where there is typically no signal) engenders artifacts in reconstructed susceptibility property maps. These errors are most egregious in the boundary regions of the object and affect mean susceptibility, susceptibility anisotropy, and tissue structure orientation measurements. Greater understanding of susceptibility mapping artifacts will aid in developing the tools necessary for accurate and reliable susceptibility imaging techniques. |
| 2843 | Computer #28 |
Improved magnetic dipole kernel for reconstruction methods in quantitative susceptibility mapping |
1Department of Electrical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile, 2Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, Chile, 3German Center for Neurodegenerative Deceases (DZNE), Magdeburg, Germany, 4Institute of Neuroradiology, University Medicine Goettingen, Goettingen, Germany, 5Department of Neurology and Center of Clinical Neuroscience, Charles University in Prague, 1st Faculty of Medicine and General University Hospital in Prague, Praha, Czech Republic, 6Department of Neurology and Center for Stroke Research Berlin (CSB), Charité-Universitaetsmedizin, Berlin, Germany, 7Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine, Berlin, Germany, 8Medical Image Analysis Center, Basel, Switzerland |
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We propose a new magnetic dipole kernel for QSM reconstructions based on the discrete cosine transform and discrete derivative operators. The method minimises aliasing artefacts, reduces noise and improves detection of small objects and tissue interfaces. This is demonstrated numerically with a synthetic phantom and qualitatively with an ultra-high resolution QSM of post-mortem brain tissue. |
| 2844 | Computer #29 |
Simultaneous Quantification of Blood Vessel Caliber and Oxygenation via Multi-Voxel Joint Utilization of Magnitude and Phase (MV-JUMP) |
1Electrical Engineering and Computer Science, MIT, Cambridge, MA, United States, 2Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 3Richard M Lucas Service Center for Imaging, Stanford University, Stanford, CA, United States, 4Health Sciences and Technology, Harvard/MIT, Cambridge, MA, United States |
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Accurate, quantitative determination of blood vessel oxygenation and caliber from GRE data would be useful for assessing local perfusion and oxygen consumption. However, partial-volume effects confound both measurements. Vessel edges are blurred and discretized, hampering assessment of vessel size. Oxygenation can be measured from GRE phase, but partial-volume effects with other tissues often contaminate these measurements. In this work, we present a novel approach that simultaneously obtains accurate measurements of vessel caliber and oxygenation state for vessels nearly parallel to B0. This approach is demonstrated in numerical and in vivo experiments. |
| 2845 | Computer #30 |
Estimating Shared Relaxation and Susceptibility Tensor Eigenvectors Enhances STI Tractography in the Heart, Kidney, and Brain |
1Center for In Vivo Microscopy, Duke University, Durham, NC, United States, 2Biomedical Engineering, Duke University, Durham, NC, United States, 3Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States, 4Brain Imaging & Analysis Center, Duke University, Durham, NC, United States, 5Radiology, Duke University, Durham, NC, United States |
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Conjoint relaxation and susceptibility tensor imaging (CRSTI) uses both magnitude- and phase-derived tensor data to compute susceptibility-based tractography in magnetically anisotropic tissues. CRSTI reduces image artifacts that appear in traditional susceptibility tensor imaging by taking advantage of mutual eigenvector data in relaxation and susceptibility tensors. We present an efficient conjoint tensor estimation algorithm and demonstrate improved susceptibility-based tractography in myofibers, renal tubules, and axon fiber bundles. As susceptibility imaging is sensitive to both microstructure and cellular content, CRSTI is a potential tool for studying disease in tissues throughout the body. |
| 2846 | Computer #31 |
Assessing Response to Hyperoxic Respiratory Challenges with Quantitative Susceptibility Mapping in Primary Malignant Brain Tumors |
1Department of Radiology, University Hospital Zurich, Zurich, Switzerland, 2Institute of Biomedical Engineering, ETH Zurich, Zurich, Switzerland, 3Department of Radio-Oncology, University Hospital Zürich, Zurich, Switzerland |
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Glioblastoma multiforme and anaplastic astrocytoma are aggressive brain tumors which can form large heterogeneous lesions, parts of which respond with varying sensitivity to radiotherapy. The long-term goal of the current study is to characterize the oxygenation state of tumors or parts of heterogeneous large tumors by quantitative-susceptibility-mapping, under hyperoxic respiratory challenge, and yield valuable information, e.g., for an improved dose shaping, which may lead to an improved therapy outcome. The preliminary results suggest that QSM may indeed be capable of differentiating the response of well vascularized tumor-tissue volumes to respiratory-induced hypoxia from the response of likely necrotic and edematous volumes. |
| 2847 | Computer #32 |
High-Resolution Quantitative Susceptibility Mapping of Free-Breathing Human Lung |
1Brain Imaging and Analysis Center, Duke University, Durham, NC, United States, 2Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, Salt Lake City, UT, United States, 3Department of Radiology, School of Medicine, Duke University, Durham, NC, United States |
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In the pulmonary tissue, strong-susceptibility-induced field perturbation is mostly a source of artifact resulting in severe distortion. Breathing artifacts pose further challenges, especially in pediatric populations. These artifacts coupled with the intrinsic low proton SNR make it extremely difficult to perform quantitative susceptibility mapping in the lung. State-of-the-art STAR-QSM method combined with the recently developed locally low rank parallel imaging method could further reduce motion artifacts and allow free-breathing high resolution QSM of the lung. |
| 2848 | Computer #33 |
How to compare SHARP parameters? New definitions in physical rather than numerical space |
1Institute of Biomedical Engineering, ETH Zurich, Zurich, Switzerland, 2Department of Radiology, University Hospital Zurich, Zurich, Switzerland, 3Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany, 4Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States, 5Friedrich Schiller University Jena, Michael Stifel Center for Data-driven and Simulation Science Jena, Jena, Germany, 6MRI Clinical and Translational Research Center, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States |
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Sophisticated Harmonic Artifact Reduction for Phase data (SHARP) is a method widely used for removal of background fields, which is one of the steps of Quantitative susceptibility mapping (QSM). In this work we analyzed SHARP using different radii between 1 and 15mm, with varying regularization parameters in mm-1, determined optimum values and showed two cases that can arise due to wrong interpretation of the original parameters. A direct conversion of the old-parameters-scheme to the new one is presented. Best and extreme cases for parameters are demonstrated for simulated models and an in-vivo case, and the effects on images are discussed. |
| 2849 | Computer #34 |
Automated tissue phase and QSM estimation from multichannel data |
1Martinos Center for Biomedical Imaging, Charlestown, MA, United States |
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An automated method for tissue phase and susceptibility estimation from multichannel data is proposed. Using ESPIRiT with virtual body coil calibration on multichannel data, phase-sensitive coil combination is achieved without an additional reference acquisition. This is shown to perform similarly to SNR-optimal Roemer combination that requires additional reference body and head coil acquisitions. Estimation of the tissue phase from the combined data is posed as a regularized inverse problem using the spherical mean value property. The extension of the technique to single-step Quantitative Susceptibility Mapping is also demonstrated on 2D, 3D and Simultaneous MultiSlice data. |
| 2850 | Computer #35 |
Susceptibility-driven oscillations in Multi-Gradient-Echo MRI reflect axonal microstructures |
1Champalimaud Neuroscience Program, Champalimaud Center for the Unknown, Lisbon, Portugal, 2CFIN/MindLab, Aarhus Universitet, Århus C, Denmark |
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Characterizing white matter (WM) microstructure in terms of axon size and volume fraction remains elusive and typically requires extremely strong gradients to resolve water diffusion in micron-sized axons. Here, we develop and apply a new approach for quantifying WM microstructure using a simple multi-gradient-echo (MGE) sequence. We use rat spinal cord as our experimental system, and show that, at long echo times, oscillations in the signal decay emerge, which can be used to robustly quantify the WM microstructure. The ensuing parameteric maps segment the SC into its underlying microstructures. The simplicity of the approach bodes well for many future applications. |
| 2851 | Computer #36 |
Magnetic Saturation and Field Dependency on Magnetic Susceptibility of Ferumoxytol |
1Radiology, New York University School of Medicine, New York, NY, United States, 2The MRI Institute for Biomedical Research, Waterloo, ON, Canada, 3Radiology, Wayne State University, Detroit, MI, United States |
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The magnetization of diamagnetic and paramagnetic materials is proportional to the strength of the applied magnetic field, with a constant of proportionality (χ) known as the magnetic susceptibility. While the magnetization of ferromagnetic and superparamagnetic materials is much higher than that of diamagnetic and paramagnetic materials, it becomes saturated in strong magnetic fields. We show that the magnetization of USPIO agents such as Ferumoxytol saturates at around 1.5T. This introduces a perceived inverse correlation between apparent susceptibility and field strength. By contrast, the magnetization of GdDTPA is proportional to field strength up to 7T, as expected for a paramagnetic material. |
| 2852 | Computer #37 |
Evaluation of an Iterative Phase Replacement Method for Susceptibility Mapping in Regions with no MRI Signal |
1Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 2Institute of Nuclear Medicine, UCLH-NHS Foundation Trust, London, United Kingdom |
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Magnetic susceptibility mapping has the potential to facilitate segmentation of air and teeth in the head due to their different magnetic susceptibilities, though there is no phase signal in these regions. An iterative phase replacement method to improve the calculation of susceptibility distributions in regions with no phase signal is validated using a numerical phantom consisting of three classes: air, teeth and tissue with the phase image set to zero in the air and teeth to simulate the real case. Calculated susceptibility distributions in regions with no phase signal were not accurate and standard deviations were seen to increase in some regions, though the iterative technique improved a simple segmentation. |
| 2853 | Computer #38 |
Quantitative susceptibility mapping with discrete wavelet transform at 7T & 3T MRI |
1Kwangwoon University, Seoul, Korea, Republic of, 2Korea Basic Science Institute, Ochang, Korea, Republic of |
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A tissue characterization with susceptibility e.g., susceptibility weighted imaging (SWI), quantitative susceptibility mapping (QSM), susceptibility tensor imaging (STI), gets more attention in high field MRI. Using a numerical phantom, various processing elements for QSM are analyzed. We propose a method to remove background phase using a discrete wavelet transform (DWT). The proposed DWT method shows superb performances over exiting techniques including SHARP in the QSM experiments with volunteer subjects at 7.0T and 3.0T MRI, without distortions at the susceptibility maps. |
| 2854 | Computer #39 |
Preserving vessel conspicuity and contrast in local frequency maps by processing channel phase images prior to combination |
1Biomedical Engineering Graduate Program, Western University, London, ON, Canada, 2Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada, 3Department of Medical Biophysics, Western University, London, ON, Canada |
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Local frequency shift (LFS) mapping from multi-channel acquisition is traditionally performed with channel-combined data set prior to background field removal. In this work we utilize inter-echo variance channel combination to evaluate the effect of pre-channel combination (pre-CC) phase image processing on the quality of LFS maps. We compare our results with post-channel combination (post-CC) LFS maps. The results illustrate superior performance in the contrast of LFS maps resulting from pre-CC processing compared to the post-CC LFS maps. Several examples where vessel conspicuity is lost through post–CC processing but preserved through pre-CC processing are presented. |
| 2855 | Computer #40 |
WHOLE-BODY QUANTITATIVE SUSCEPTIBILITY MAPPING IN HEALTHY SUBJECTS AND IN PATIENTS WITH IRON OVERLOAD |
1Radiology, University of Wisconsin - Madison, Madison, WI, United States, 2Experimental Radiology, Greifswald University, Greifswald, Germany, 3Medical Physics, University of Wisconsin-Madison, Madison, WI, United States |
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Magnetic susceptibility is a fundamental property of all tissues. The presence of biomaterials (e.g. iron, gadolinium) changes the susceptibility of the tissue in a direct and well-understood manner, allowing quantification of biomaterial concentration. Quantitative susceptibility mapping (QSM) techniques have been developed, largely to investigate iron and calcium deposits in the brain. The development and application of whole-body QSM may enable improved characterization and quantification of tissue pathophysiology based on a fundamental property of tissue. Thus, the purpose of this work was to develop and demonstrate the feasibility of whole-body QSM in healthy subjects and in patients with suspected iron overload. |
| 2856 | Computer #41 |
Gauging the stability of susceptibility and R2* mapping across ten sites |
1GE healthcare MR Research China, Beijing, China, People's Republic of |
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In this work, the stability of simultaneously obtained R2* and susceptibility are investigated and compared across 10 sites with identical experiment setup and post-processing hardware, as may be the case for a multi-center study.
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| 2857 | Computer #42 |
Investigation of intrascanner reproducibility of quantitative susceptibility mapping (QSM) and R2* at 3T |
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany, 2Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States, 3MRI Molecular and Translational Research Center, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States |
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In the present work, we quatitatively assessed the reproducibility of Quantitative susceptibility mapping (QSM) and effective transverse relaxation rate (R2*) in healthy volunteers at 3T scanner during multiple scanning sessions. We also investigated the QSM normalization based on 2 reference structures, Cerebrospinal fluid (CSF) and frontal White Matter (fWM).Our results indicated that QSM using CSF as reference region reveals increased scan-rescan reliability than referencing with fWM. |
| 2858 | Computer #43 |
Optimising SWI in neonates |
1Perinatal Imaging and Health, King's College London, London, United Kingdom, 2Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom |
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Susceptibility-weighted imaging (SWI) is sensitive to susceptibility changes associated with blood and and shows excellent performance in detecting hemorrhage. Infants born preterm and those with congenital heart disease are at risk of parenchymal, cerebellar or intraventricular/ germinal layer haemorrhage.As such, there is a clinical need for rapid, high resolution SWI to assess brain injury in these infants.In this work a dedicated neonatal SWI protocol is proposed that aims to maximize the obtainable signal while minimizing the expected WM/GM contrast to improve sensibility to local field variations. |
| 2859 | Computer #44 |
Quantification of Liver Iron Concentration using the Apparent Susceptibility of Vessels |
1The MRI Institute for Biomedical Research, Waterloo, ON, Canada, 2School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada, 3Tianjin First Central Hospital, Tianjin, China, People's Republic of, 4Siemens Healthcare, MR Collaborations NE Asia, Beijing, China, People's Republic of, 5Department of radiology, Wayne State University, Detroit, MI, United States |
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Quantification of liver iron concentration (LIC) is critical for the diagnosis of patients with liver iron overload. LIC is conventionally measured using R2/R2* mapping methods which have limited accuracy and precision, partly due to the non-linear relation between relaxation rate and iron concentration. Quantitative susceptibility mapping (QSM) has been shown to be effective in quantifying cerebral iron deposition. For LIC quantification using QSM, the challenges include dealing with air-tissue interface in the abdomen in background field removal and solving the ill-posed inverse problem. Here we show a method which uses the apparent susceptibility of liver vessels for LIC quantification. |
| 2860 | Computer #45 |
Investigating the magnetic susceptibility of skeletal muscle at 7 T |
1Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom |
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There has been longstanding interest in the anisotropic magnetic properties of muscle tissue, but to date there has been little examination of these properties using MRI. Here we describe an initial examination of muscle via field mapping measurements carried out at 7T on phantoms containing small pieces of muscle embedded in agar. The results indicate that the susceptibility of this muscle is diamagnetic (~-100ppb) with respect to agar and only weakly anisotropic (<5 ppb). There was a significant uniform and orientation-independent positive frequency offset inside the muscle of 30 ppb most likely due to chemical exchange effects. |
| 2861 | Computer #46 |
Quantitative susceptibility mapping including a white matter Lorenzian correction |
1CIBM-AIT, EPFL, Lausanne, Switzerland, 2Centre for Cognitive Neuroimaging, Donders Institute, Nijmegen, Netherlands |
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Quantitative susceptibility mapping (QSM) has been shown to provide quantitative measures of iron concentration in deep gray matter structures. In white matter, QSM is affected not only by local susceptibility but also by the local organized microstructure of axons and its myelin coating where reduced water signal exists. Recently, the anisotropic effect of myelin susceptibility was shown to be minor compared to the effect of its compartmentalization. In this work, the Lorentzian correction was, for the first time, implemented in a COSMOS like QSM reconstruction. The correction does not affect deep gray matter structure values, but creates QSM maps of isotropic susceptibility and maps of the susceptibility of cylindrically organized inclusion spaces. |
| 2862 | Computer #47 |
Combining phase information from multi-channel coils using a short TE reference scan (COMPOSER): evaluation with a range of coils and comparison with other approaches at 7T |
1High Field Magnetic Resonance Centre, Medical University of Vienna, Vienna, Austria, 2Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 3Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia, 4Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, 5Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria, 6Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland, 7Department of Biomedical Engineering, University of Basel, Basel, Switzerland |
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A new method for combining phase images from multi-channel radio-frequency coils in the absence of a volume reference coil is presented and tested with calf, breast and head coils at 7 Tesla. This approach, called COMbining Phased array data using Offsets from a Short Echo-time Reference, or COMPOSER, is shown to yield phase matching between channels which is better than a rival, widely adopted reference-free method (MCPC-3D) and comparable with the reference-based Roemer method. COMPOSER can be used with all coil arrays, including the next generation of PTx coils where the transmit array may not be engineered to receive signal. |
| 2863 | Computer #48 |
Quantitative susceptibility mapping (QSM) as a means to monitor cerebral hematoma treatment |
1Brain Imaging and Analysis Center, Duke University, Durham, NC, United States, 2Department of Radiology, Ren Ji Hospital, Shanghai Jiaotong University, Shanghai, China, People's Republic of, 3Department of Radiology, School of Medicine, Duke University, Durham, NC, United States |
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Quantitative susceptibility mapping (QSM) based on GRE phase data can provide an accurate measurement of the hemorrhage volumes by removing blooming artifacts inherent in traditional T2* weighted imaging. It is shown here that new developed STAR-QSM can effctively remove the streaking artifact and provide more reiable measure for hematoma volume and suceptibility quantification, e.g., for evaluating the patients per- and post-treatment. By taking the avantage of high quality susceptibility maps, susceptibility information can help to provide furhter classification of the hemorrhage stage. |
| Exhibition Hall | Monday, May 9, 2016: 14:15 - 15:15 |
| 2864 | Computer #49 |
Magnetic Resonance Perfusion Quantification using QR-based Deconvolution |
1Samsung R & D Institute, Bangalore, India, 2Medical System Lab, Samsung Electronics, Suwon, Korea, Republic of |
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The standard approaches for performing the deconvolution in post-processing of DSC-MRI data is singular value decomposition (SVD) and Frequency-Domain Deconvolution (FDD), which are known to be relatively less accurate and requires a careful choice of threshold to obtain physiologically meaningful results. In this work, a method that utilizes QR decomposition to perform the deconvolution is proposed. The QR method is a well-known dimensionality reduction technique for solving ill-conditioned linear system of equations and known to have better numerical properties in obtaining a regularized solution. It is shown that the proposed method provides superior results compared to the standard deconvolution methods. |
| 2865 | Computer #50 |
Assessment of an automated method for AIF voxel selection for renal filtration rate estimation from DCE-MRI data. |
1Department of Biomedical Imaging, The University of Leeds, Leeds, United Kingdom, 2School of Computing, The University of Leeds, Leeds, United Kingdom, 3Department of Renal Medicine, Salford Royal hospital NHS foundation trust, Salford, United Kingdom |
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In this work we present an automated arterial input function voxel selection method for estimation of glomerular filtration rate (GFR) from renal DCE-MRI data. We assessed the agreement of GFR values estimated using the automated method with values estimated using semi-automatic expert selection and nuclear medicine techniques using 16 acquired data sets. The automated method successfully selected voxels within the aorta in all cases. The agreement between the expert and automated method was in some cases poor. However, the agreement of the automated method with the nuclear medicine results was similar to that of the expert method. |
| 2866 | Computer #51 |
The quantitative research of the vertebral microvascular permeability and fat fraction in alloxan-induced diabetic rabbits |
1Renmin Hospital of Wuhan University, wuhan, China, People's Republic of, 2GE healthcare, wuhan, China, People's Republic of |
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To estimate the effect of diabetes on vertebral bone marrow, twelve young New Zealand White rabbits including alloxan-induced diabetic rabbits (n=6) and the controls (n=6) underwent sagittal magnetic resonance imaging (IDEAL-IQ, DCE-MRI) of lumbar at each time point. At the week of 16, all rabbits were killed. L7 sampling, HE staining and immunoperoxidase CD31 labeling were performed. According to statistical analysis, there were statistically significant differences of the vertebral DCE-MRI parameters and fat fraction (FF) between the diabetic groups and controls at each time point. The variety of vertebral microvascular permeability was strongly associated with the increasing vertebral fat deposition. |
| 2867 | Computer #52 |
Saturation Recovery Fast Spin Echo Method for Rapid T1 Mapping of Mouse Kidney |
1Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, United States, 2Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, United States |
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In this study, a saturation recovery fast spin echo method was developed for fast T1 mapping of mouse kidney at a temporal resolution of ~3 min. The validity of this method was first demonstrated in vitro on a phantom with different concentrations of MnCl2 by comparing to the conventional spin echo T1 mapping method and a previously validated saturation recovery Look-Locker (SRLL) method and then in vivo on mouse kidneys at both pre- and post-MnCl2 infusion by comparing to SRLL. |
| 2868 | Computer #53 |
SPIO-enhanced MRI as a nondestructive in vivo Method to assess Vascularization of a 3D Matricel Collagen Scaffold planted on the Chorioallantoic Membrane of the Chick Embryo in ovo |
1Division of Visceral and Transplantation Surgery, University Hospital Zurich, Zurich, Switzerland, 2Institute for Biomedical Engineering, ETH and University Zurich, Zurich, Switzerland, 3Plastic Surgery and Hand Surgery, University Hospital Zurich, Zurich, Switzerland |
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MRI has been presented as a nondestructive in vivo readout to report perfusion capacity in biomaterials planted on the CAM in the living chick embryo in ovo. Perfusion capacity was assessed through changes in T1 relaxation pre and post injection of a paramagnetic contrast agent, Gd-DOTA (Dotarem®, Guerbet S.A.). Hence local contrast agent concentration was dependent on perfusion, vascular permeability and extravascular compartment size. In the present study we explore intravascular SPIO particles of 30-40 nm size (FeraSpin series M, Viscover™, Miltenyi Biotec, Germany) that stay in the vasculature to deliver a more direct measure of vascularization. |
| 2869 | Computer #54 |
Influence of Linear and Non-linear Conversions of T1-weighted Signal Intensity to Gadolinium Concentration on Contrast Kinetic Model Parameters: A Simulation Study |
1Bernard and Irene Schwartz Center for Biomedical Imaging, Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University School of Medicine, New York, NY, United States |
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The purpose of this study was to assess the effect of linear and non-linear signal-to-concentration conversion methods on the estimation of contrast kinetic parameters in T1-weighted dynamic contrast-enhanced MRI. A simulation study was conducted, using the Generalized Kinetic Model with a population-based arterial input function, to compare the two conversion methods in terms of the uncertainty in contrast kinetic parameter estimation, influence by the error in the pre-contrast T1 value, and the effect of flip angle, one of the important scan parameters. The results provide useful information on how to interpret the results with the linear conversion method. |
| 2870 | Computer #55 |
Measurement of Absolute Cerebral Blood Volume using Velocity-Selective Pulse Trains |
1Radiology, Johns Hopkins University, Baltimore, MD, United States, 2F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States |
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Current MRI techniques for quantification of absolute cerebral blood volume (CBV) are all contrast-based. To reduce associated risks and cost, we proposed a non-contrast-enhanced (NCE) MRI method using a velocity-selective (VS) spin labeling approach for CBV measurement at 3T. Gray matter CBV values across 5 subjects are 2.4±0.2 mL/100g for blood flowing between the encoded cutoff velocities of 0.5cm/s and 3.1cm/s, with a GM/WM ratio of 1.9±0.3. |
| 2871
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Computer #56 |
Pulmonary Perfusion using pseudo-Continuous Arterial Spin Labeling |
1Bioengineering, University of Texas at Dallas, Richardson, TX, United States, 2Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 3Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States |
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Cardiac triggering is regularly used in arterial spin labeled (ASL) pulmonary perfusion imaging to minimize pulsatile flow effects. A cardiac-triggered pseudo-continuous ASL (pCASL) sequence was previously implemented to improve the SNR of lung perfusion, but was found to be sensitive to variations in heart rate due to the prolonged TR, causing the data acquisition to occasionally occur during systole. The purpose of this study was to investigate methods to reduce this cardiac cycle sensitivity in pulmonary perfusion images using pCASL, including cardiac triggering the acquisition and alternative readouts such as a projection acquisition. |
| 2872 | Computer #57 |
Comparison of pseudo-continuous arterial spin labeling with [15O]-water PET at baseline and after Diamox: a simultaneous PET-MRI study |
1Radiology, Stanford University, Stanford, CA, United States, 2Applied Science Lab, GE Healthcare, Menlo Park, CA, United States |
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The ability to noninvasively image cerebral blood flow (CBF) would help with assessment of many cerebrovascular disorders including stroke. We compared simultaneous PET-MRI measurements of CBF by arterial spin labeling MRI and the [15O]-water PET reference standard in healthy volunteers. ASL and PET revealed similar spatial distributions of perfusion in the brain and reliably detected CBF augmentation due to Diamox administration. ASL MRI also demonstrated lower scan-rescan coefficient of variation across the gray matter relative to PET. Going forward, we will perform kinetic modeling of absolute CBF from [15O]-water PET and consider potentially different radiotracer arterial input functions (derived from the PET-MRI images themselves) that occur in different brain perfusion states. |
| 2873 | Computer #58 |
Improving ASL Perfusion MRI-based Functional Connectivity Analysis with Robust Principal Component Analysis |
1Hangzhou Normal University, Hangzhou, China, People's Republic of |
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ASL perfusion fMRI has much less neurovascular effects than BOLD fMRI, but its application in time-series analysis is still depreciated due to the low signal-to-noise-ratio (SNR). Robust principal component analysis (RPCA) decomposing the original data into a smoothly varying low-rank component and a residual component with sparse signal. In this study, we used RPCA to denoise ASL MRI. Our results showed that RPCA can markedly increase the sensitivity of ASL MRI-based functional connectivity analysis. |
| 2874 | Computer #59 |
Reduction of motion artefacts in multi-shot 3D GRASE Arterial Spin Labelling using Autofocus |
1Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom, 2Translational Imaging Group, UCL, London, United Kingdom, 3Developmental Imaging and Biophysics Section, UCL Institute of Child Health, London, United Kingdom, 4Centre for Medical Imaging, UCL, London, United Kingdom, 5Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, United Kingdom |
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Multi-shot 3D acquisition schemes offer an efficient method to obtain ASL data with good SNR and spatial resolution. However, multi-shot techniques are susceptible to motion-induced artefacts that can severely degrade image quality. In this work, we investigate the use of the autofocus algorithm to correct k-space phase inconsistencies caused by inter-shot motion, and demonstrate its effectiveness at improving image sharpness and removing artefacts in motion-corrupted 3-shot 3D GRASE data. As such, autofocus offers a retrospective approach to improve the quality of multi-shot ASL data, with the associated improvements in CBF quantification accuracy and reproducibility. |
| 2875 | Computer #60 |
The potential of arterial spin labeling with full labeling duty cycle (FDC-ASL) to measure blood flow and transit delay simultaneously with substantially improved sensitivity and efficiency |
1Radiology, UC San Diego, La Jolla, CA, United States, 2Psychiatry, UC San Diego, La Jolla, CA, United States |
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Pulsed arterial spin labeling (PASL) has the potential to achieve full labeling duty cycle with almost instant labeling. We explore here a new PASL-based fast labeling and imaging method for measuring blood flow (BF) and transit delay (TD) simultaneously, through a series of simulations. The results show that the BF and the TD can be accurately estimated. This new approach shows promise for substantially improved sensitivity and efficiency compared with conventional methods using PASL or pseudo-continuous ASL. |
| 2876 | Computer #61 |
CBF correction in vessel selective ASL perfusion using vessel selective MRA as a calibration |
1GE healthcare MR Research China, Beijing, China, People's Republic of, 2Department of Precision Instrument, Tsinghua University, Beijing, China, People's Republic of |
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CBF quantification in territorial arterial spin labeling (tASL) is difficult in practice due to unknown labeling efficiency as compared to non-selective ASL perfusion. It is also difficult to derive this labeling efficiency based on perfusion map due to the irregular cerebral region and potential multi-vessel supply. In this work, tASL MRA is used as a reference scan to derive the needed labeling efficiency for correct derivation of the CBF quantification. |
| 2877 | Computer #62 |
ASL in the MriCloud: a platform-independent, installation-free tool for arterial-spin-labeling analysis |
1Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2AnatomyWorks, LLC, Baltimore, MD, United States, 3Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States, 4Center for Imaging Science, Johns Hopkins University, Baltimore, MD, United States, 5Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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There has been a surging interest in using arterial spin labeling (ASL) MRI to measure cerebral perfusion. Current downloadable ASL analysis toolboxes are still primitive compared those for fMRI and DTI, and involves issues of software compatibility and computational burden. Here we describe a cloud-computing-based tool for comprehensive analysis of ASL-MRI. With this tool, the user can obtain CBF maps and ROI-averaged CBF values without having to install any software on the local computer. The maintenance of software upgrades will be performed by the developer. This tool may prove valuable and timely in accommodating the recent surging interest in ASL-MRI. |
| 2878 | Computer #63 |
Partial Volume Effects Correction for QUASAR ASL: A Spatially Regularised Approach |
1Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom, 2Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet Glostrup, Glostrup, Denmark, 3Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet Blegdamsvej, Copenhagen, Denmark |
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The precise quantification of cerebral blood flow (CBF) using ASL MRI is affected by signal contaminations and partial volume (PV) effects. Among the numerous ASL techniques, QUASAR ASL exhibits unique characteristics of separating tissue and arterial blood components, allowing the bias from the arterial blood component being controlled. However, PV effects remain a critical issue that has not been fully addressed for QUASAR ASL. Here, we investigate a spatially regularised method to correct PV effects in QUASAR ASL using a three-component model. The results indicate that the proposed method preserves more spatial variations than the linear regression method. |
| 2879 | Computer #64 |
Time Efficient ASL Imaging with Segmented Multiband-acquisition (TEAISM) |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Siemens Medical Solutions USA Inc., Minneapolis, MN, United States |
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Recent studies have demonstrated the benefits of multi-band (MB) EPI for high-resolution whole brain PCASL imaging. However, the intrinsic nature of spatially interleaved simultaneous slice acquisition of MB-EPI requires a post-labeling delay larger than the longest arterial transit time in the brain, resulting in SNR efficiencies in the inferior or middle-inferior slices only comparable to or lower than those in SB-EPI PCASL imaging. To overcome the limitations of traditional MB-EPI and further improve SNR efficiencies of whole-brain high-resolution PCASL imaging, an alternative imaging acquisition strategy has been proposed and demonstrated: Time Efficient ASL Imaging with Segmented Multiband-acquisition (TEAISM). |
| 2880 | Computer #65 |
SCRUB: A Structural Correlation and Empirical Robust Bayesian Method for ASL Data |
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States |
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We propose SCRUB, a data cleaning technique to improve cerebral blood flow (CBF) estimation based on arterial spin labeling (ASL) data. The method consists of (i) an outlier detection and removal stage and (ii) a subsequent voxel-wise empirical robust Bayesian estimation step. Compared to alternative options, SCRUB provided (i) better retest agreement between CBF values obtained from ASL scans of elderly Controls in ADNI database acquired 3 months apart, and (ii) better discrimination between Controls and patients with Alzheimer’s disease (AD) based on CBF values in several regions of interest which are sensitive to AD related changes. |
| 2881 | Computer #66 |
Time Varying Velocity Labeling Efficiency Correction in Arterial Spin Labeling |
1Biomedical Engineering/ Cardiology, University of Southern California/ Children's Hospital Los Angeles, Los Angeles, CA, United States, 2Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, United States, 3Hematology, Children's Hospital Los Angeles, Los Angeles, CA, United States, 4Children's Hospital Los Angeles, Los Angeles, CA, United States |
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In this study we propose a time varying correction technique for pseudo continuous arterial spin labeling efficiency. We compare this correction method to other correction methods and phase contrast MRI. |
| 2882 | Computer #67 |
A Theoretical Comparison of Multi-Delay Arterial Spin Labeling Methods |
1FMRIB Centre, NDCN, University of Oxford, Oxford, United Kingdom, 2Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom |
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This study aims to investigate the ideal labeling and delay parameters for single-delay, multi-delay and time-encoded pCASL and compare their theoretical performance in cerebral blood flow (CBF) and bolus arrival time (BAT) estimation under realistic noise levels over two BAT ranges: healthy (500ms-1500ms) and disease (500ms-3000ms). |
| 2883 | Computer #68 |
Effect of labeling position on MT effects and Bolus Arrival Time |
1Neurology, University of Pennsylvania, Philadelphia, PA, United States, 2Radiology, University of Pennsylvania, Philadelphia, PA, United States |
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The effects of labeling location were assessed in pseudo-continuous ASL by performing kinetic modeling of data acquired at multiple post-labeling delays and by assessing the ratio of mean ASL intensity to M0. Labeling location differences resulted in significant MT effects on raw ASL data, and produced nonlinear effects on bolus arrival time across vascular distributions. |
| 2884 | Computer #69 |
Pharmacokinetic modeling driven Rapid Adaptive Spatio-Temporal Resolution for Accelerated (RASTRA) DCE-MRI |
1Dayananda Sagar Institutions, Bangalore, India |
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The proposed method combines Compressed Sensing (CS) framework with view sharing to accelerate Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCEMRI). A novel method to combine k-spaces of different regions (Temporal Region (TR) and Spatial Region (SR)) is carried out in this work. View sharing is adapted to combine the kspace, by mapping samples from SR region frames onto corresponding frames in TR region to improve the edge information, achieving better reconstruction with higher acceleration. It is shown that the proposed method provides better Pharmacokinetic(PK) maps at higher acceleration rates than existing methods with minimum error, as qualified by NRMSE values. |
| 2885 | Computer #70 |
A simple and low cost Dynamic contrast enhancement MRI perfusion phantom |
1Medical Imaging Research Centre, Dayananda Sagar Institutions, Bangalore, India |
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DCE MRI technique is widely used in tissue characterization and tissue perfusion. Current work focuses on the design and development of a low cost in vivo DCE phantom for providing a reference standard for quantitative validation and the ability to generate Signal Intensity curves similar to arterial input functions. Poly vinyl Alcohol material was used in the phantom to mimic tissue perfusion characteristics and obtain signal intensity curves for different flow rates. We obtained similar curves compared to Arterial Input Function and were able to control flow rates through different tube and pore sizes. |
| 2886 | Computer #71 |
A Correlation Study between DCE-MRI Quantitative Parameters and Immunohistochemical Labeling Indices in Nasopharyngeal Carcinoma |
1Fujian Provincial Cancer hospital, Fuzhou, China, People's Republic of, 2Fujian Provincial Cancer Hospital, Fuzhou, China, People's Republic of, 3Philips Healthcare, Shanghai, China, People's Republic of, 4Philips Healthcare, Hong Kong, China, People's Republic of |
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We assessed correlations between DCE-MRI quantitative parameters with immunohistochemical labeling indices which reflect tumor hypoxia (HIF-1α), tumor angiogenesis (VEGF, MVD) and tumor proliferation (Ki67) in nasopharyngeal carcinoma(NPC). We found that HIF-1α positive group was significantly correlated with VEGF positive expression and MVD count respectively. Ktrans and Kepwas positively associated with HIF-1α positive expression, VEGF positive expression and MVD respectively .There were significantly positive correlations between vp and the VEGF expression, MVD count respectively. However, there were no significant relationship between the Ki67 expression and any DCE-MRI quantitative parameters in our study. |
| 2887 | Computer #72 |
The effect of blood brain barrier disruption on the cerebral blood flow measurement with dynamic susceptibility contrast MRI: Comparison study between SPION and Gd-DOTA |
1UNIST, Ulsan, Korea, Republic of, 2Ulsan, Korea, Republic of |
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Dynamic susceptibility contrast MRI (DSC MRI) is widely used for cerebral blood flow (CBF) measurement for diseases, such as stroke and cancer.1-2 Fundamental assumption of DSC-MRI based CBF measurement is that contrast agent is non-leaking with intact blood brain barrier (BBB).3 Here, we investigate the effect of BBB disruption on the CBF measurement, especially for stroke model utilizing serial dual acquisitions using DOTAREM and SPION. As SPION remains as intravascular agent, while DOTAREM becomes extravasating agent with BBB disruption, dual CBF acquisitions with both agents provide quantitative way to characterize the effect of BBB disruption on CBF measurements with DSC-MRI. |
| Exhibition Hall | Monday, May 9, 2016: 14:15 - 15:15 |
| 2888 | Computer #73 |
Staging deep vein thrombosis using quantitative Magnetization Transfer |
1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 2Department of Radiology, Guangzhou Panyu Central Hospital, Guangzhou, China, People's Republic of, 3The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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There is an urgent need for a quantitative imaging technique that can stage deep vein thrombosis (DVT) and guide thrombolysis treatment. In the present study, we explored the ability of quantitative Magnetization transfer (qMT) technique as a non-invasive means to stage thrombi based on their macromolecular content. Thrombi in the inferior vena cava were formed using a Mouse Complete Stasis Model. A two-pool MT mathematical model was adapted to fit high-resolution MT data of excised thrombi samples. The results clearly showed that bound proton fraction (BPF) is a useful parameter for distinguishing aged blood clots from freshly formed ones. |
| 2889 | Computer #74 |
Noninvasive Assessment of Renal Fibrosis Using Magnetization Transfer MRI in Murine Renal Artery Stenosis |
1Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, United States, 2Department of Radiology, Mayo Clinic, Rochester, MN, United States, 3Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, United States, 4Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States |
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In this study, magnetization transfer was used to measure renal fibrosis in a murine model of renal artery stenosis. A collagen phantom study was performed to optimize the irradiation-offset frequency of MT pulses. Renal fibrosis by in vivo MT and ex vivo histology or hydroxproline assay showed a good correlation, suggesting that MT could be used to assess renal fibrosis. In addition, MT successfully captured the physiological changes at different stages of renal fibrosis, indicating that MT was capable of monitoring the longitudinal development of functionally significant renal fibrosis. |
| 2890 | Computer #75 |
Increasing the inhomogeneous magnetization transfer (ihMT) signal in vivo with high amplitude, low duty cycle irradiation |
1Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, 2CRMBM-CEMEREM UMR 7339, CNRS-AMU, Aix Marseille Université, Marseille, France |
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High power, off-resonance irradiation as utilized in ihMT/MT can saturate pools of bound magnetization before they exchange in tissues. Observation of such saturation phenomena is limited by power constraints in-vivo and by attenuation of the free pool magnetization. A technique for studying and enhancing saturation effects using relatively short bursts of higher power irradiation is evaluated. The results provided 2-5 fold increases in ihMTR (depending on average power and offset frequency). Such short duration, high power pulses offer a new window to probe exchange kinetics and dipolar order effects, as well as enhancing the quality and feasibility of ihMT imaging. |
| 2891 | Computer #76 |
On-resonance Variable Delay Multi Pulse Scheme for Imaging of Fast-exchanging Protons and semi-solid Macromolecules |
1F. M. Kirby Center, Kennedy Kriger Institute, Baltimore, MD, United States, 2Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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An on-resonance variable delay multi-pulse (onVDMP) scheme was developed for separation and quantification of magnetization transfer contrast (MTC) and total fast-exchanging protons (TFP) contributions. Phantom studies of glucose, bovine serum albumin (BSA) and hair conditioner show the capability of onVDMP to separate out exchangeable protons with different exchange rates by their unique signal buildup curves. Quantitative MTC and TFP maps acquired on healthy mouse brains showed strong gray/white matter contrast for the slowly transferring MTC protons while the TFP map was more uniform across the brain. |
| 2892 | Computer #77 |
Theoretical and Experimental Optimization of a 3D Steady-State Inhomogeneous Magnetization Transfer (ihMT) Gradient Echo Sequence: Boosting the ihMT Sensitivity with Sparse Energy Deposition |
1CRMBM, UMR 7339 CNRS, Aix-Marseille University, Marseille, France, 2Pôle d'Imagerie Médicale, CEMEREM, APHM, Marseille, France, 3Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States |
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Inhomogeneous Magnetization Transfer (ihMT) has shown improved specificity for myelinated tissue as compared to conventional MT. Recently, fundamental developments have led to theoretical modeling of the ihMT effect. In this study forward modeling of a steady-state ihMT gradient echo (GRE) sequence is used to guide experimental optimization for various TRs, power levels and ihMT pulse-train duration. An efficient RF-energy deposition scheme is demonstrated for relatively long TRs, leading to ihMTRs as high as 15-17% and 10-12% in WM at 1.5T and 3T, respectively. This opens new perspectives for patient studies at clinical field strength and ihMT implementation at higher field strength. |
| 2893 | Computer #78 |
Stratification of graded acute stroke metabolic injury with magnetization transfer and relaxation-normalized amide proton transfer (MRAPT) pH-weighted MRI |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, 2Department of Radiology, Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China, People's Republic of, 3Cerebrovascular Diseases Research Institute, Xuanwu Hospital of Capital Medical University, Beijing, China, People's Republic of, 4Neuroprotection Research Laboratory, Department of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States |
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Amide proton transfer (APT) MRI probes amide protons from endogenous proteins/peptides, which has shown promising results in defining tissue acidosis. pH MRI complements perfusion and diffusion MRI for enhanced stratification of heterogeneous ischemic tissue injury. However, the endogenous APT effect depends not only on pH but also on tissue water content, MRI relaxation rates, and experimental conditions. There are also concomitant RF irradiation effects including direct RF saturation, magnetization transfer and nuclear overhauser effects (NOE). Our study evaluated magnetization transfer and relaxation-normalized APT (MRAPT) MRI in an animal model of acute ischemic stroke that enabled semiautomatic segmentation of graded ischemic tissue injury. |
| 2894 | Computer #79 |
CEST-mDixon for Breast Lesion Characterization at 3T |
1Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 2Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 3Philips Research, Hamburg, Germany, 4Philips Medical Systems, Cleveland, OH, United States |
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In this work, the feasibility of mDixon-based CEST-MRI for breast lesions characterization at 3T was explored. The mDixon technique was used to acquire pure water CEST images without fat contamination. The B0 maps derived from mDixon technique were used for field inhomogeneity correction. Human studies demonstrated marked differences in MTRasym between malignant and healthy tissue in hydroxyl range (0.8-1.8 ppm) and amide range (3.1-4.1 ppm). In addition, the width of the Z-spectrum was reduced in malignant vs healthy breast tissue. The results suggest that the CEST-mDixon has the potential as a robust detection and characterization tool of breast malignancy. |
| 2895 | Computer #80 |
Identification of the Origin for Amide Proton Transfer (APT) Imaging Signals in Multiple Pathologies |
1Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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APT imaging can provide endogenous contrast related to the mobile amide proton concentration, amide proton exchange rate (depending on tissue pH), and other tissue and experimental parameters. Here, based on the correlations between quantified APT signals and combined parameter of water proton concentration and water T1 (T1w/[water proton]), we attempted to reveal the origin for APT imaging signals in multiple disease models. The results showed no significant correlations between APT signals and the T1w/[water proton]. Our findings clearly indicated that the APT signals is primarily related to the mobile amide proton concentration and amide proton exchange rate. |
| 2896 | Computer #81 |
B0-calibrated and motion-registered dynamic CEST MRI of muscles undergoing exercise |
1Radiology, University of Illinois, Chicago, IL, United States, 2Bioengineering, University of Illinois, Chicago, IL, United States, 3Center for MR Research, University of Illinois, Chicago, IL, United States |
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Artifacts arising from tissue motion and static field inhomogeneities can heavily impact the measurement of metabolites concentration in CEST-MRI experiments in vivo. We present a correction strategy applied to CEST-MRI of creatine concentration during muscle exercise. Corrections consisted in image registration by means of a demons algorithm and signal calibration over static field offsets map at baseline, without the need of additional scanning. After correction, results are in accord with conventionally corrected data and published results. This method is shown to be effective in dynamic studies, where a high temporal resolution and coverage is required. |
| 2897 | Computer #82 |
Localized, gradient-reversed ultrafast z-spectroscopy in vivo at 7T |
1Department of Radiology, Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, United States |
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Ultrafast z-spectroscopy can be collected by saturating the nuclear spins with an RF pulse in the presence of a gradient, effectively encoding the offset frequency spatially across a voxel and allowing full z-spectra to be collected in a single shot. When asymmetry analysis is applied, frequencies on one physical side of the voxel are compared with those on the other physical side. This can be a problem if there is inhomogeneity or partial voluming. By acquiring an additional z-spectrum with the gradient polarity reversed, mixed z-spectra can be created in which the positive and negative offset frequencies come from the same side of the voxel. This method is more robust to inhomogeneity and partial voluming typically found in vivo as demonstrated here with studies on 7T in human brain. |
| 2898 | Computer #83 |
Can CEST be used as biomarker in Huntington’s disease? |
1Institute of Neurology, University College London, London, United Kingdom, 2Medical Physics, University College London Hospital, London, United Kingdom, 3Center of Medical Imaging, University College London, London, United Kingdom, 4Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada, 5Department of Neurology, University Medical Center, Leiden, United Kingdom, 6Department of Neurology, Ulm University, Ulm, Germany, 7HighQ foundation, CHDI, New York, NY, United States |
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Huntington’s is a hereditary disease caused by the HTT gene, resulting in the aggregation of mutant huntingtin in the cytoplasm. CEST, known to be affected by protein concentration and structure, was considered a potential biomarker for a clinical trial and comparison with MT, T1 and T2 relaxometry. Data were acquired in n=54 HD patients and n=46 healthy individuals. Comparison of CEST revealed significant differences (p<0.05) in the putamen and globus pallidus regions which did not correlate with any changes in relaxometry or MT, suggesting that CEST might be able to provide additional contrast to the already existing methods. |
| 2899 | Computer #84 |
Imaging the pH by means of CEST-responsive iopamidol: normal and AKI model studies |
12nd Affilicated Hospital, Shantou University Medical College, Shantou, China, People's Republic of, 2Hanshan Normal University, Chao zhou, China, People's Republic of, 3Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States |
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The promising imaging technique of chemical exchange saturation transfer (CEST) MRI, which is sensitive to microenvironment properties including pH, metabolites, temperature, metal ions, and enzymatic activities, has been increasingly applied in vivo such as acute ischemia, infection and cancer. The aim of this work was to observe the differentiation between normal and acute kidney injury (AKI) using echo-planar imaging sequence (EPI) as well as the sensitive ratiometric methods under 7T magnetic field. |
| 2900 | Computer #85 |
Comparison of 3D CEST acquisition schemes: steady state versus pseudo-steady state |
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, Nottingham, United Kingdom |
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Chemical Exchange Saturation Transfer (CEST) has gained much popularity due to its unmatched sensitivity to dilute labile protons when compared to other MRI techniques. Of particular interest are two CEST effects: Amide Proton Transfer (APT, CEST of amides) and Nuclear Overhauser Enhancement (NOE). Fast-paced developments for CEST resulted in the design of multiple CEST imaging sequences. This raises the obvious question as to which sequence to use and in what particular applications. Two pulsed volumetric CEST acquisition schemes are currently available in the literature. The first is based on the standard Magnetization Transfer imaging technique: a steady-state (SS) acquisition with alternating brief saturation and image acquisition. The second is based on the preparation of the magnetization before a long readout, where the prolonged saturation reaches a pseudo-steady state (PS) before the image acquisition. In this report, these two CEST acquisition schemes, optimized for maximum sensitivity to APT and NOE effects through Bloch-McConnell simulations, were systematically compared for the same spatial resolution, brain coverage and scan time. |
| 2901 | Computer #86 |
GluCEST imaging of spinal cord in a mouse model of Friedreich ataxia |
1CEA/DSV/I2BM/MIRCen, Fontenay-aux-Roses, France, 2CNRS Université Paris-Saclay UMR 9199, Fontenay-aux-Roses, France, 3Department of Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France, 4INSERM U596, Illkirch, France, 5CNRS UMR7104, Illkirch, France, 6Université de Strasbourg, Strasbourg, France, 7INSERM UMS 27, Fontenay-aux-Roses, France |
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Friedreich Ataxia (FA) is the most common form of recessive inherited ataxia which induces severe neurological disabilities and reduced life expectancy. As glutamate has been shown to be a potential biomarker of neurodegenerative diseases, we used Chemical Exchange Saturation Transfer imaging of glutamate (gluCEST) in order to characterize our mouse model of FA and to monitor glutamate alterations in the spinal cord. GluCEST images revealed decrease of glutamate level in FA mouse model compared to control littermates, especially in the lumbar part. These results demonstrate the potential of gluCEST in providing innovative and relevant biomarkers of FA. |
| 2902 | Computer #87 |
Tissue Characterization with Fast High Resolution Magic Angle Spinning (HRMAS) CEST Spectroscopy |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, 2Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States, 3Department of Mathematics and Statistics, Hanshan Normal University, Chaozhou, China, People's Republic of |
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Z-spectrum is conventionally acquired through multiple experiments with selective saturation at different frequency offsets of interest, leading to extreme long acquisition time. Here, we employ gradient-encoding to substantially accelerate the acquisition of Z-spectrum. This speedup in combination with higher spectral resolution provided by high resolution magic angle spinning (HRMAS) allows rapid quantification of chemical exchange rates of CEST agents, monitoring dynamic processes and fast tissue characterization. The approach was validated in phantom and used for characterization of brain tissues after ischemic stroke. |
| 2903 | Computer #88 |
GluCEST imaging: a relevant biomarker of Huntington’s disease. |
1CEA/DSV/I2BM/MIRCen, Fontenay-aux-Roses, France, 2CNRS Université Paris-Saclay UMR 9199, Fontenay-aux-Roses, France, 3Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany, 4Centre for Rare Diseases, University of Tuebingen, Tuebingen, Germany, 5Paris-Saclay Institute of Neuroscience, Université Paris-Sud, UMR 9197, Orsay, France, 6Centre National de la Recherche Scientifique, Orsay, France, 7INSERM UMS 27, Fontenay-aux-Roses, France |
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Huntington’s disease (HD) is an inherited neurodegenerative disease characterized by motor, cognitive and psychiatric symptoms. As glutamate has been shown to be a potential biomarker of neurodegenerative diseases, we used Chemical Exchange Saturation Transfer imaging of glutamate (gluCEST) to map cerebral glutamate distribution in mouse and rat models of HD. A decrease of [Glu] was measured in the striatum by MRS and gluCEST. In addition, good spatial resolution of gluCEST over MRS allowed identification of other afflicted brain regions such as corpus callosum. These results demonstrate the potential of gluCEST in providing relevant biomarkers of HD in the whole brain. |
| 2904 | Computer #89 |
Accelerating CEST Imaging with Spatial-Temporal Sparse Dictionary Learning |
1Radiology, Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States |
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This work investigates accelerating CEST imaging. The original blind compressive sensing method assumes that a few functions are enough to represent the dynamic behavior, and the coefficient matrix should be sparse. In CEST imaging, z-spectrum shows group sparsity in the same compartment. So not only the coefficients matrix is sparse but also the transformation of the coefficients matrix is sparse, such as total variation and wavelets. The proposed method addresses this prior information and further improves the original BCS method, demonstrating a better estimation of the CEST effect at high reduction factors for both Cartesian and radial sampling patterns. |
| 2905 | Computer #90 |
Use of Yb-HPDO3A probe for CEST-MRI pH mapping in glioblastoma mouse models |
1Dept of Molecular Biotechnologies & Health Sciences, University of TORINO (IT), Torino, Italy, 2CLINATEC-CEA-INSERM UA01 – CHU –UJF Grenoble (FR), Grenoble, France, 3CLINATEC-CEA Grenoble (FR), Grenoble, France |
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MRI maps of extracellular/extravascular pH distribution in glioblastoma mouse model (U87 cells) have been obtained by administrating YbHPDO3A CEST probe. This molecule has potential in a clinical setting as it displays analogue properties (stability and in vivo pharmacokinetic) of its analogue clinically approved Gd-HPDO3A (ProHance). Furthermore, glioblastoma pH maps have been correlated with histology (H/E, Hif-1a and Ki-67 staining). The assessment of glioblastoma pHe could be used to monitor tumor development and to target acidic tumor regions using innovative responsive pH therapies. |
| 2906 | Computer #91 |
Comparison of gagCEST and sodium MRI in evaluating knee cartilage in vivo at 7 Tesla |
1Department of Biomedical Imaging and Image-Guided Therapy, High Field MR Center, Medical University of Vienna, Vienna, Austria, 2CD Laboratory for Clinical Molecular MR Imaging, Vienna, Austria, 3Department of Orthopedic Surgery, Medical University of Vienna, Vienna, Austria, 4Novartis Institutes for Biomedical Research, Basel, Switzerland |
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There are several methodological and data processing issues in gagCEST, which complicate the translation of this method into clinical practice. For assessing performance of the gagCEST protocol optimized in our laboratory, corrected signal intensities from sodium images were used as a reference. The results demonstrate a good correlation between both methods, although the small magnitude of the gagCEST effect and the low resolution in sodium images require carefully optimized methodology and long measurement times. It can be concluded that the gagCEST method can be useful in evaluating early degeneration of articular cartilage at 7 Tesla. |
| 2907
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Computer #92 |
Chemical shift artifact of the third kind: Implications for gradient-echo based contrast enhanced imaging |
1Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA, United States, 2Radiology, Breast Imaging Division, Hospital of the University of Pennsylvania, Philadelphia, PA, United States, 3Radiology, Abdominal Imaging Division, Hospital of the University of Pennsylvania, Philadelphia, PA, United States, 4Radiology, University of Pennsylvania, Philadelphia, PA, United States |
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A common subtraction band artifact in breast MRI was not understood, causing reduced confidence in clinical interpretation. The source of the artifact is shown to be a subtle chemical shift effect between fat and water in the presence of contrast enhancement. The phenomenon is now generalized and characterized at all off-resonance angles. Strong echo-time and fat signal dependence may lead to enhancement errors as a function of scanner hardware, field strength and fat suppression limitations. A time and SNR-equivalent in-phase VIBE sequence eliminates the artifact; gradient-echo based contrast enhanced imaging can be performed in-phase to eliminate these important potential pitfalls. |
| 2908 | Computer #93 |
Fixed Angle Single Rotation CEST (FASR-CEST) sequence for reducing saturation time |
1School of Physics, Peking University, Beijing, China, People's Republic of, 2MR Research Group, GE Healthcare China, Beijing, China, People's Republic of |
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In CEST imaging, when saturation time is not sufficient long (empirically smaller than 0.8s), rotation effect would appear and contaminate with saturation effect, making the signal unavailable for further analysis. Considering the inhomogeneity of $$$B_{0}$$$ and $$$B_{1}$$$ in reality, we propose a novel Fixed Angle Single Rotation CEST(FASR-CEST) sequence to overcome the restriction, successfully reducing the saturation time to about 0.5s while keeping identical effect as CEST sequence with long saturation time, with the help of analytical calibration method in another abstract. Effect of the sequence is verified with vitro and in vivo data. |
| 2909 | Computer #94 |
T1D-w ihMT: Dipolar Relaxation time weighted imaging using inhomogeneous Magnetization Transfer |
1CRMBM / CNRS 7339, Aix Marseille University, Marseille, France, 2Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States |
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The inclusion of a dipolar reservoir in the existing two pool model for MT allowed interpreting the inhomogeneous MT (ihMT) signal as a dipolar order effect -characterized by a relaxation time T1D - within motion restricted molecules. In this study, we demonstrate that an ihMT signal can actually be evidenced in any component with non-trivial T1D value. Adjustment of the dual frequency irradiation efficiency by increase of Δt, the repetition rate of consecutive saturation pulses, filters the signal of shorter T1D components. This provides a means to realize T1D-weighted imaging, a new source of MR contrast between tissues. |
| 2910 | Computer #95 |
Improvement of in vivo glucoCEST imaging in rat brain using inverse z-spectrum analytical scheme at 7.0 T |
1Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, 2Department of Medical Imaging, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan, 3Translational Imaging Research Center, Taipei Medical University, Taipei, Taiwan, 4Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan, 5Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan, 6Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan, 7Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan |
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GlucoCEST have been proposed to assess the discrepant concentrations of glucose in vitro. However, it is still a challenge to obtain accurate signals from glucose in vivo. Our preliminary finding demonstrated that the proposed analytical scheme provides an alternative to extract glucose profile and could be more robust to the field inhomogeneity, which may be helpful in further implementation in disease models. |
| 2911 | Computer #96 |
A fast chemical exchange saturation transfer imaging scheme based on spatiotemporal encoding |
1Department of Electronic Science, Xiamen University, Xiamen, China, People's Republic of, 2Department of Communication Engineering, Xiamen University, Xiamen, China, People's Republic of |
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Chemical exchange saturation transfer (CEST) is widely exploited in magnetic resonance imaging (MRI) because of its special quantitative contrast mechanisms. To overcome the long acquisition time required by fast spin-echo multi-slice imaging and alleviate the sensitivity to field inhomogeneity and chemical shift effects appeared in echo planar imaging, we proposed a CEST imaging scheme based on spatiotemporally encoded magnetic resonance imaging (SPEN MRI). Experimental results validated the feasibility and capability of the new scheme. |
| Exhibition Hall | Monday, May 9, 2016: 15:15 - 16:15 |
| 2912
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Computer #1 |
Ventilation imaging with sulfur hexafluoride in free-breathing mice: initial experience |
1Core Facility Small Animal MRI, Ulm University, Ulm, Germany, 2Target Discovery Research, In-vivo imaging laboratory, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany, 3Department of Internal Medicine II, Ulm University, Ulm, Germany |
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Functional information of the lung is of great importance for staging and monitoring lung disease. Imaging of lung ventilation has been addressed by inhalation of polarized gases like Helium or Xenon. Major limitation of this technique rises from the high costs of equipment and gases. As an efficient alternative to polarized gases, the use of fluorinated gases has been proposed. In pre-clinical application these have always been used in combination with intubation, which does not realistically reflect the ventilation during free breathing. In this contribution the imaging of ventilation in mice with fluorinated gases during free-breathing is addressed. |
| 2913 | Computer #2 |
3D Lung Ventilation 1H Imaging Using a Respiratory Self-Navigated Stack-of-Stars Sequence in Comparison to 2D Fourier Decomposition |
1Institute of Diagnostic and Interventional Radiology, Hanover, Germany, 2German Centre for Lung Research, Hanover, Germany |
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Fourier Decomposition (FD) is a lung function imaging technique with a high clinical potential. Nevertheless the 2D acquisition leads to long acquisition times for complete lung scans and the 3D breathing motion might lead to errors in the ventilation measurements. Self-navigated sequences offer the possibility to reconstruct images in different respiratory states. Using a stack-of-stars sequence, a method for 3D fractional ventilation (FV) imaging is demonstrated for six healthy volunteers and compared with FV calculated by 2D FD. The two methods show a good agreement. Additionally, 3D FV depicts 3D lung motion, which is not adequately detected with 2D FD. |
| 2914 | Computer #3 |
PETRA Lung MRI: Towards Robust Lung Imaging with Patient Comfort and with Improved Contrast |
1Siemens Healthcare, Los Angeles, CA, United States, 2Siemens Healthcare, Erlangen, Germany |
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With recent developments in ultra-short TE (UTE) MRI sequences such as PETRA with the respiratory triggering and the segmented acquisition, MRI has shown a potential of being a viable radiation-free alternative to the incumbent gold standard CT lung imaging. Within a volunteer validation study (n=14), the current work demonstrates a recent progress in the PETRA lung MRI towards its robustness and its applicability to all patient populations. The proposed solution improves patient comfort and image contrast by suppressing the unintended high intensity signals from surrounding tissues. |
| 2915 | Computer #4 |
Histogram based Analysis of Lung Perfusion of Children after Congenital Diaphramatic Hernia Repair |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, 2Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany, 3Department of Pediatric Surgery, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany, 4Department of Neonatology, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany |
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Reported measured lung perfusion data of 2-year old children after congenital diaphragmatic hernia repair was evaluated by regions of interest (ROI) within the acquired 3D volume. In this work a histogram based approach is used to characterize the distribution of perfusion in the whole left and right lung, and suitable quantities to characterize the distribution are extracted.
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| 2916
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Computer #5 |
Balanced SSFP pulmonary signal enhancement after contrast agent injection |
1Radiological Physics, Dep. of Radiology, University of Basel Hospital, Basel, Switzerland, 2Department of Biomedical Engineering, University of Basel, Basel, Switzerland |
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In contrast to the common view that Gd-based contrast agents have only marginal/limited effect on balanced steady state free precession (bSSFP) from its $$$T_2/T_1$$$ signal properties, we will demonstrate that especially for lung imaging single-dose contrast agent administration increases the parenchymal signal nearly up two fold. |
| 2917
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Computer #6 |
Fast 3D quantitative 1H ventilation imaging of the human lung at 1.5T with SSFP |
1Radiological Physics, Dep. of Radiology, University of Basel Hospital, Basel, Switzerland, 2Department of Biomedical Engineering, University of Basel, Basel, Switzerland, 3Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University Hospital Heidelberg, Heidelberg, Germany, 4Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany |
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Monitoring lung ventilation is of great interest to assess pulmonary function and disease progression. Here, a novel, fast, and simple three-dimensional (3D) quantitative in vivo 1H imaging method is introduced, reflecting regional ventilation information. To this end, typically five ultra-fast balanced steady state free precession (ufSSFP) scans are repetitively performed in breath-hold from which a respiratory index map, $$${\gamma}$$$, is derived. The new measure $$${\gamma}$$$ shows high reproducibility in healthy volunteers and high sensitivity to respiratory defects, such as in patients with COPD. |
| 2918
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Computer #7 |
Four-Dimensional Respiratory Motion-Resolved Sparse Lung MRI |
1Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States, 2University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 3Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland, 4Center for Biomedical Imaging (CIBM), Lausanne, Switzerland |
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A four-dimensional (4D) respiratory motion-resolved UTE MRI method is presented for free-breathing lung MRI with isotropic spatial resolution. Center-out radial half-projection k-space data are continuously acquired using a 3D golden-angle UTE sequence. The radial k-space data are retrospectively sorted into distinct respiratory states, resulting in an undersampled 4D dataset (kx-ky-kz-respiration) using a respiratory motion signal extracted from the acquired data. The undersampled 4D data are reconstructed by exploiting sparsity along the new respiratory dimension. The proposed approach enables free-breathing lung MRI with 100% scan efficiency, allowing for assessment of lung tissue in arbitrary orientations at different respiratory states. |
| 2919 | Computer #8 |
Fourier Decomposition MRI using the SENCEFUL Approach for Non-Contrast-Enhanced Ventilation Imaging in Cystic Fibrosis Patients |
1Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany, 2The Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia, 3Department of Pediatrics, University Hospital Würzburg, Würzburg, Germany |
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Fourier Decomposition MRI using the SENCEFUL approach is a recent development in functional lung MRI allowing for site-resolved assessment of lung function. The purpose of the present study is to evaluate its feasibility for ventilation imaging in patients with cystic fibrosis. Seven cystic fibrosis patients and 7 healthy volunteers were examined, lung ventilation maps were reconstructed and quantitative ventilation measurements were performed in tidal and deep breathing. Mean quantitative ventilation was significantly lower for patients with cystic fibrosis when compared to the healthy controls. The ventilation maps indicated increased ventilation inhomogeneity in cystic fibrosis patients. |
| 2920 | Computer #9 |
Tobacco smoke shortens T1 in a mouse model of COPD |
1Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden, 2AstraZeneca R&D, Mölndal, Sweden, 3Medtech West, Chalmers University of Technology, Gothenburg, Sweden, 4Antaros Medical, BioVenture Hub, Mölndal, Sweden, 5Department of Medical Physics, Lund University, Translational Sciences, Malmö, Sweden |
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Tobacco smoking is the main cause of COPD. MRI may improve the characterization of COPD where lung T1 mapping has been used to study lung disease. We investigated whether tobacco smoke exposure affects lung T1 in a mouse model with repeated T1 readouts and biological measurements. Free breathing 3D-UTE T1 maps of the lungs were weekly performed over one month in mice exposed to air or tobacco smoke. The lung T1 was shortened in the tobacco smoke exposed mice, most likely due to early signs of smoking-induced lung pathology. Consequently, T1 is a potential biomarker of lung disease. |
| 2921
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Computer #10 |
Respiratory self-gating in 3D UTE lung acquisition in small animal imaging |
1Core Facility Small Animal MRI, Ulm University, Ulm, Germany, 2Target Discovery Research, In-vivo imaging laboratory, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany, 3Department of Neuroradiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany, 4Department of Internal Medicine II, Ulm University, Ulm, Germany |
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1D (k-space center) and 3D (sliding window 3D reconstruction) have been evaluated for respiratory retrospective self-gating for Quasi Random UTE-3D lung acquisition in freely breathing rats. Low-resolution 3D GRASP reconstruction allowed the extraction of an effective gating signal from changes in lung-liver interface position. The 1D center-of-k-space method did not yield sufficient gating signal fidelity, most likely caused by the only limited changes of the anatomy in the investigated volume, and to a lesser extent intensity modulations introduced by residual eddy-currents. |
| 2922
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Computer #11 |
Longitudinal Assessment of Pulmonary Permeability in a Mouse Model of Lung Fibrosis |
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, United States |
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Idiopathic pulmonary fibrosis is a fatal condition without effective treatment. Given evidence that vascular leak promotes fibrosis, we assessed whether pulmonary leak could be quantified using dynamic MRI and an intravascular tracer. In a mouse model we observed that permeability to albumin rose sharply on day 3 after insult, returned to baseline by day 5 and increased moderately between days 5-13. To our knowledge this is the first report of the time course of vascular leak in pulmonary fibrosis. The proposed method could be useful for studying the role of lung permeability in fibrosis and for monitoring of treatment response. |
| 2923 | Computer #12 |
Imaging of Lung Conductivity Using Ultrashort Echo-Time Imaging |
1Philips Research Europe, Hamburg, Germany |
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Reliable MR imaging of lung tissue could be an important element of diagnosing lung-related diseases. The very short T2 components of lung tissue, one of the main problems of lung imaging, can be visualized using ultrashort echo times (UTE). Furthermore, UTE sequences allow the determination of conductivity of the imaged tissue. This study shows the principle feasibility of UTE to image lung conductivity, examining healthy volunteers. Obtained conductivity was lower for inspiration breath hold than expiration breath hold, which is the expected behaviour due to corresponding fraction of air (with nearly zero conductivity) inside lungs during inspiration and expiration. |
| 2924 | Computer #13 |
Pulmonary Fourier decomposition MRI compared to multiple breath washout and spirometry: A preliminary study in Primary Ciliary Dyskinesia |
1Division of Radiological Physics, Deparment of Radiology, University Hospital of Basel, Basel, Switzerland, 2Department of Biomedical Engineering, University of Basel, Basel, Switzerland, 3Department of Pediatric Pneumology, University Children's Hospital Basel (UKBB), Basel, Switzerland, 4Division of Respiratory Medicine, Department of Pediatrics, University Children's Hospital of Bern, Bern, Switzerland, 5Institute of Diagnostic Radiology, Interventional Radiology and Nuclear Medicine, Ruhr-University of Bochum, Bochum, Germany, 6Department of Pediatric Pneumology, University Children's Hospital of Ruhr University Bochum at St Josef-Hospital, Bochum, Germany |
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In this work, the feasibility of contrast-media-free pulmonary Fourier decomposition (FD) MRI is assessed in patients with primary ciliary dyskinesia (PCD). An automatic evaluation of regional functional defects on fractional ventilation and perfusion FD maps has been developed. Furthermore, the lung function evaluated using FD MRI is compared to the parameters obtained using multiple breath washout technique and spirometry. Statistical analysis was used to find significant correlations between FD MRI and lung function techniques. |
| 2925 | Computer #14 |
Whole Lung Morphometry with Hyperpolarised 3He Gas Diffusion MRI - 3D Multiple b-value Acquisition and Compressed Sensing |
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom |
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Compressed sensing (CS) was implemented to reduce scan time and facilitate acquisition of 3D multiple b-value 3He diffusion-weighted (DW) MRI data for whole lung morphometry. A fully-sampled 3D DW-MRI dataset was retrospectively undersampled using CS simulations to determine optimal k-space undersampling patterns. Whole lung morphometry measurements derived from prospective 3-fold undersampled 3D multiple b-value DW-MRI were compared to 3D and 2D fully-sampled equivalents. Good agreement was obtained between lung morphometry measurements indicating 3D multiple b-value 3He DW-MRI with CS can provide reliable measurements of whole lung morphometry within a single breath-hold. |
| 2926 | Computer #15 |
Single breath washout imaging – regional phase III slope mapping with rapid hyperpolarized gas MRI |
1University of Sheffield, Sheffield, United Kingdom |
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Single breath washout (SBW) is a whole lung pulmonary function test that has been shown to be sensitive to early changes in lung disease. Of particular clinical interest has been the Phase III slope (SIII) as the concentration decay between 25-75% of the exhaled volume. In this work rapid lung imaging of exhaled hyperpolarized gas is used to acquire 2D images of SBW of subjects expiring to residual lung volume. The ability to calculate regional SIII from those time resolved images is demonstrated in healthy volunteers. |
| 2927 | Computer #16 |
Incorporation of prior knowledge of the signal behavior into the compressed sensing framework for accelerated acquisition in hyperpolarized gas diffusion MRI |
1Department of Bioengeering and Aerospace Engineering, Universidad Carlos III de Madrid, Madrid, Spain, 2Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain, 3Centro de Investigación en Red de Salud Mental (CIBERSAM), Madrid, Spain |
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Diffusion MRI measurements using hyperpolarized gases are generally acquired during patient breath hold, which yields a compromise between achievable image resolution, lung coverage and number of b-values. In this work, we propose a novel method that incorporates the knowledge of the signal decay into the reconstruction (SIDER) to accelerate the acquisition of MR diffusion data by undersampling in both spatial and b-value dimensions. SIDER is assessed by restrospectively undersampling diffusion datasets of normal volunteers and COPD patients. Results suggest that accelerations of at least x7 are achievable with negligible effect in the estimates of diffusion parameters. |
| 2928 | Computer #17 |
3D Multi-Parametric Acquisition of 3He Lung Ventilation Images, Lung Diffusion Morphometry and T2* Maps with Compressed Sensing |
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom |
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Whole-lung coverage 3He ventilation images, maps of ADC, alveolar dimension (LmD), and T2* were acquired in a single breath-hold using a multiple-interleaved 3D sequence with compressing sensing (CS). A fully-sampled three-interleaved ADC and T2* dataset was acquired for CS simulations, to determine the optimal k-space undersampling patterns. A prospective, 3-fold undersampled 3D five-interleaved dataset was acquired with CS and parametric maps were compared to those calculated from fully-sampled datasets. CS-derived ADC and LmD values showed good agreement with fully-sampled equivalents. CS-derived T2* values were lower than fully-sampled ones due to the smoothing process of the CS reconstruction. |
| 2929 | Computer #18 |
Improved fitting of 129Xe spectroscopy identifies three dissolved-phase resonances in the human lung |
1Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States, 2Medical Physics Graduate Program, Duke University, Durham, NC, United States, 3Department of Biomedical Engineering, Duke University, Durham, NC, United States, 4Department of Radiology, Duke University Medical Center, Durham, NC, United States |
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Hyperpolarized 129Xe experiences chemical shifts between the lung airspaces, interstitium, and capillary beds, enabling functional information to be directly probed. However, in order to realize the potential of these chemical shifts, the spectrum must be carefully decomposed. Previous methods have assumed only two dissolved-phase resonances exist in the human lung and have used inconsistent 0 ppm reference frequencies. Here we present novel non-linear fitting of complex exponentially decaying FIDs and demonstrate that the dissolved phase signal can be robustly decomposed into three dissolved-phase resonances. We present updated frequencies and widths using and appropriately adjusted 0 ppm reference value. |
| 2930 | Computer #19 |
Improving quantitative Hyperpolarized 129Xe gas exchange MRI in idiopathic pulmonary fibrosis |
1Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States, 2Medical Physics Graduate Program, Duke University, Durham, NC, United States, 3Department of Radiology, Duke University Medical Center, Durham, NC, United Kingdom, 4Department of Biomedical Engineering, Duke University, Durham, NC, United States, 5Department of Radiology, Duke University Medical Center, Durham, NC, United States |
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While gas-exchange imaging with 129Xe holds great potential for enhancing both the diagnosis and followup of IPF, the quantitative ability of these techniques is currently limited by the SNR and spatial resolution afforded by the limited dissolved-phase signal and highly undersampled acquisition. Here we tune our reconstruction for these challenging conditions, and demonstrate improvements in image quality. We then quantify the loss of gas exchange in the apex and base of the lung and show that there is significantly reduced gas exchange in the basal regions of subjects with IPF relative to healthy controls. |
| 2931 | Computer #22 |
Magnetic Resonance Elastography of the Anterior Mediastinal Mass at 3T: a Preliminary Study |
1Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China, People's Republic of, 2GE heathcare MR research China, Beijing, China, People's Republic of |
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Magnetic resonance (MR) elastography depitcs the elastic properties of tissues of interest has been primarily applied in the work-up of diagnosis for hepatic fibrosis. Theoretically, interference fringes could be visualized on the elastogram due to the miscalculation of the interaction between the attenuated propagations of shear wave and the tissue overlying or surrounding to the investigated subject, which might be one of the main concern that limited the clinical potentials of MRE. We propose an investigation on the feasibility of MR elastography in characterizing the mechanical properties of anterior mediastinal masses with the consideration of the relatively superficial location of these entities, therefore few interactions between the shear wave and subject unexpected were produced during the process of elasticity mapping. It was demonstrated in our study that anterior mediastinal mass in various etiology of thymic carcinoma, thymoma, and lymphoma has distinct elastic properties. MR elastography was helpful in distinguishing the thymic carcinoma from lymphoma. |
| 2932 | Computer #20 |
Prediction of Longitudinal FEV1 Decline in Smokers with Hybrid Hyperpolarized 3He MRI |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Bioengineering, University of Pennsylvania, Philadelphia, PA, United States, 3Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, United States, 4Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, United States, 5Johns Hopkins University, Baltimore, MD, United States |
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Aside from the superior diagnostic power that HP gas MRI provides through imaging unique aspects of lung function, it is evident that the underlying mechanisms that lead to subsequently evident global changes in the lung function in future are detectable through regional and functional imaging using HP gas MRI. |
| 2933 | Computer #21 |
Hyperpolarized 129Xe MRI ventilation in pediatric cystic fibrosis lung disease: safety and sensitivity |
1Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 2Department of Physics, Washington University in St. Louis, St. Louis, MO, United States, 3Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States, 4Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 5Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States |
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We demonstrate hyperpolarized 129Xe MRI in healthy pediatric control subjects and cystic fibrosis patients as young as age 7, for the first time. Subjects experienced a transient nadir in SpO2 that quickly returns to baseline with normal breathing. Despite having similarly high lung function (i.e., normal FEV1), CF patients had nearly 4-fold increase in 129Xe ventilation defect volume compared to their healthy peers, with statistical significance. Importantly, ventilation defects were present even in CF patients with FEV1 near or exceeding 100% predicted, suggesting that 129Xe MRI is more sensitive to early CF lung disease than traditional clinical spirometry. |
| 2934 | Computer #23 |
Assessment of Pleural Effusion in Dengue Fever |
1A*STAR-NUS Clinical Imaging Research Centre, Singapore, Singapore, 2Department of Medicine, National University Hospital Singapore, Singapore, Singapore, 3Duke-NUS Graduate Medical School, Singapore, Singapore |
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In this study we assess the feasibility of using MRI for measurement of pleural effusion in Dengue Fever. 30 subjects with confirmed Dengue infection were scanned using T2-weighted HASTE MRI and chest x-rays (CXRs) at baseline and 4-8 days follow-up. Fluid accumulation in the pleural cavity was assessed for both modalities. For MRI, significantly different fluid accumulations were measured between baseline and follow-up (p=0.002). The fluid accumulations were all below the detectability limit of CXR. As such, MRI provides a sensitive measurement of pleural effusion in dengue fever and can be used to track fluid accumulation over time. |
| Exhibition Hall | Monday, May 9, 2016: 15:15 - 16:15 |
| 2935 | Computer #25 |
Quantitative assessment and follow-up of hepatocellular carcinoma in rat livers using clinical 3T MRI. |
1Division of Abdominal and Transplantation Surgery, Hepato-pancreato-biliary Centre, Department of Surgery, Geneva University Hospital and Faculty of Medicine, Geneva, Switzerland, 2Division of Radiology, Geneva University Hospital and Faculty of Medicine, Geneva, Switzerland, 3Institute of Anatomy, Paracelsus Medical University, Salzburg, Austria |
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In vivo liver cancer research commonly uses rodent models of liver tumor growth. One of the limitations of such models is the lack of accurate and reproducible endpoints for dynamic assessment tumor nodules. We used 3T clinical MRI to quantify tumor volume over time and correlate to gold standard histological volumes and blood levels of α-fetoprotein in two rat orthotopic models of hepatocellular carcinoma (HCC). Combination of 3D isotropic gradient echo for accurate volume and T2 for contrast provided appealing correlation. We have developed a 3D volume quantification method that enables follow-up and analysis of complex tumor morphology. |
| 2936 | Computer #26 |
Clinical feasibility of free-breathing gadoxetic acid-enhanced liver MRI using incoherent undersampling in patients with transient dyspnea |
1Radiology, Seoul National University Hospital, Seoul, Korea, Republic of, 2Siemens Healthcare, Erlangen, Germany, 3Siemens Healthcare Korea, Seoul, Korea, Republic of, 4Radiology, NYU School of medicine, New York, NY, United States |
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Acquisition of optimal late arterial phase is essential for focal liver lesion diagnosis and detection at gadoxetic acid-enhanced liver magnetic resonance imaging (MRI). However, it is often challenging to obtain late arterial phase due to short arterial window and frequent involuntary motion during arterial phase. We attempted to characterize the frequency, onset, and duration of the involuntary motion after gadoxetic acid injection and whether acceptable quality of late arterial phase can be obtained using incoherent undersampling technique. |
| 2937 | Computer #27 |
A Retrospective, Multicenter, Intra-individual Study Based on LI-RADS 2014: Unenhanced combined contrast-enhanced MRI Elevates the HCC probability Category Compared with Multiphasic CT in Patients with Cirrhosis Induced by HBV Infection |
1Radiology, Peking University First Hospital, Beijing, China, People's Republic of, 2Beijing, China, People's Republic of |
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This study was to compare the category of unenhanced combined contrast enhanced MR imaging (MR) and Multiphasic CT (CT) in the diagnosis of HCC based on LI-RADS 2014 in patients with cirrhosis induced by HBV infection. We restropectively collected patients who had both undergone CT and MR imaging within 30 days and had pathologically proved HCC. A radiologist using LI-RADS 2014 recored the imaging features and the category of all the lesions. The result showed that MR showed higher LI-RADS category compared with CT, and had better ability for the showing of some imaging features. Thus, we concluded that MRI can elevate the LI-RADS category and is recommended in the initial evaluation of suspected HCC priority to CT. |
| 2938 | Computer #28 |
Assessing Liver Fibrosis in Patients with Chronic Hepatitis B: Comparison of T1 Mapping with Gd-EOB-DTPA-enhanced 1.5T MRI, Aspartate Aminotransferase-to-Platelet Ratio Index and Fibrosis-4 |
1Shanghai Institute of Medical Imging, Zhongshan Hospital of Fudan University, Shanghai, China, People's Republic of, 2Zhongshan Hospital of Fudan University,Shanghai Institute of Medical Imging, Shanghai, China, People's Republic of, 3Zhongshan Hospital of Fudan University, Shanghai, China, People's Republic of |
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Hepatobiliary-phase gadoxetic acid-enhanced MR imaging may reflect liver function and was reported to be able to predict liver fibrosis stage with higher reliability. Aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 (FIB-4) are widely used non-invasive tests that estimate liver fibrosis. We compared the diagnostic performance of T1 mapping on Gd-EOB-DTPA-enhanced 1.5T magnetic resonance imaging (MRI), APRI and FIB-4 for evaluating the severity of liver fibrosis in 118 patients with chronic viral hepatitis B, and the results showed The HBP T1 relaxation time measurement on gadoxetic acid-enhanced appears superior to unenhanced, D% (the reduction rate) of T1 relaxation times, the APRI and FIB-4 index in differentiating advanced liver fibrosis. |
| 2939 | Computer #29 |
Multiparametric functional MR imaging for evaluation of hepatic warm ischemia-reperfusion injury in rabbit models |
1Radiology, Tianjin First Central Hospital, Tianjin, China, People's Republic of, 2Transplantation, Tianjin First Central Hospital, Tianjin, China, People's Republic of, 3MR Collaborations NE Asia, Siemens Healthcare, Beijing, China, People's Republic of, 4Siemens Healthcare GmbH, Erlangen, Germany |
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Hepatic warm ischemia-reperfusion injury (WIRI) is clinically relevant in liver transplantation. We undertook this study to determine the feasibility of using IVIM, DTI, and BOLD MR imaging for the characterization of hepatic WIRI. 20 hepatic WIRI models and control rabbits were examined using a 3T clinical MR scanner, which followed by biochemical and histopathological analysis. There were significant differences of Dfast, Dslow, PF, ADC, and R2* values between the two groups. There were significant correlations between MR parameters and biochemical parameters. This indicated that multiparametric functional MR imaging are noninvasive and valuable techniques for assessing the pathophysiologic changes of hepatic WIRI. |
| 2940 | Computer #30 |
Apparent Relaxivity of Gd-BOPTA in A Mixture of Water, Gd-BOPTA and Fat |
1Radiology and Imaging Science, Indiana University School of Medicine, Indianapolis, IN, United States |
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This paper is to discuss the impact of fat on the Gd-based contrast behavior in a mixture of water based Gd-BOPTA solution and fat. A set of vials, contains such mixtures with various fat fraction and Gd-BOPTA concentration, was constructed and scanned using both Turbo Spin Echo (TSE) with 3 point Dixon, and VIBE-Dixon. With VIBE-Dixon, the slopes of the regression (relaxivity) of R1 vs. [Gd] in water were very close among groups with various fat fraction; while with TSE image, the slopes of R1 vs. [Gd] in whole mixture were close among vial groups. |
| 2941 | Computer #31 |
Usefulness of Short Breath Hold High Resolution Technique (CAIPIRINHA) in Gadoxetic acid-enhanced Liver MRI: To Overcome Degraded Arterial Phase |
1Radiology, Korea University Guro Hospital, Seoul, Korea, Republic of, 2Korea University Guro Hospital, Seoul, Korea, Republic of |
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The short breath-hold high-resolution MR technique showes better HAP image quality with less degraded HAP and lower incidences of breath-hold difficulty and gadoxetic acid related dyspnea than the conventional long breath-hold MR technique. |
| 2942 | Computer #32 |
MRI Characteristics of Primary Liver Malignancies: Common and Uncommon Mimics with Histopathological Correlation - A Practical Approach |
1Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States |
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The liver is an important oncologic organ. Primary liver tumors can arise from a variety of different liver components such as hepatocytes, bile duct epithelium, neuroendocrine cells, and mesenchymal cells. We will discuss imaging and histopathological features of primary liver tumors and their common and uncommon mimics. |
| 2943 | Computer #33 |
The potentiality of MR T1rho as a biomarker for liver fibrosis evaluation |
1Radiology, Tianjin First Center Hospital, Tianjin, China, People's Republic of, 2Philips healthcare, Beijing, China, People's Republic of |
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This study evaluated the potential of T1rho for liver fibrosis evaluation and to explore the best TSL points with good B0 and B1 inhomogeneity. Thirteen healthy control subjects and eight patients with clinically diagnosed liver fibrosis were scanned 3D b-TEF sequence. T1rho map were constructed by using 7-TSLs, 6-TSLs or 3-TSLs and compared between groups. Our results showed both 7-TSLs and 6-TSLs had moderate diagnostic efficacy, and AUC of 7-TSLs was slightly higher than 6-TSLs. We conclude 7-TSLs and 6-TSLs are recommended for the diagnosis of liver fibrosis, and 7-TSLs has slightly higher diagnostic performance. |
| 2944 | Computer #34 |
Measurement of Liver Perfusion using Pseudo-Continuous Arterial Spin Labeling with Background Suppression: Approaches to Separate Portal-Venous and Arterial Perfusion |
1Section on Experimental Radiology, University of Tübingen, Tübingen, Germany, 2Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 3Department of Diagnostic and Interventional Radiology, University Hospital of Tübingen, Tübingen, Germany |
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The separation of portal-venous and hepatic arterial blood supply is important for the evaluation of chronic liver diseases and the characterization of liver lesions. The aim of this study was to investigate the capability of a pseudo-continuous arterial spin labeling sequence, to separate arterial and portal venous perfusion of the liver using a background suppression technique and different tagging plane orientations. It was demonstrated that the presented method provides high quality perfusion images of the liver without application of intravenous contrast agent and offers promising approaches for the separation of arterial and portal-venous perfusion fractions. |
| 2945 | Computer #35 |
A 3D non-rigid registration method for liver in DCE MR images |
1Philips Healthcare, shanghai, China, People's Republic of |
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The shape and position of liver is varied through respiratory movement in DCE MR liver images. A robust 3D deformable registration was employed to define the distortion between them and compensate it. As a result, the liver and vessels will be located at the exact position with the exact shape (include vessels) of the reference image after registration. |
| 2946 | Computer #36 |
MRI-based Estimation of Liver Function by Intravoxel Incoherent Motion Diffusion-weighted Imaging |
1Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, China, People's Republic of, 2School of Biomedical Engineering and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China, People's Republic of, 3Philips Healthcare, Hong Kong, China, People's Republic of, 4Philips Healthcare, Guangzhou, China, People's Republic of |
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The quantitative evaluation of hepatic function is important for monitoring patients and preoperative assessment of the hepatic reserve. This work aims to assess the sensitivity of IVIM in evaluating liver function in patients with chronic liver disease. The results demonstrate that perfusion-related parameters (D* and f) are useful for indicating the severity of liver disease, and may have the potential to become a promising non-invasive tool for monitoring liver function. |
| 2947 | Computer #37 |
Liver IVIM MR imaging: improved reproducibility of pseudo-diffusion coefficient D* via proper signal modeling |
1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, 2Graduate Institute of Oncology, National Taiwan University, Taipei, Taiwan, 3Electrical Engineering, National Taiwan University, Taipei, Taiwan |
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A new scheme was proposed to analyze intravoxel ihcoherent motion MR imaging data of the liver. The method integrated the combined use of single- and bi-exponential signal decaying models to deal with regions with absence of prominent vasculature, and the removal of data obtained at b-values less than 15s/mm2 to avoid contamination from large vessels. Results from ten healthy subjects scanned twice at 3T showed substantially improved reproducibility in the pseudo-diffusion coefficient D*, while those of the true diffusion coefficient and the profusion fraction were unaltered. Using our scheme the estimated D* mostly fall within 38 to 85x10-3 mm2/s. |
| 2948 | Computer #38 |
Value of Whole-Liver Apparent Diffusion Coefficient Histogram Analysis for Quantification of Liver Fibrosis Stages |
1Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China, People's Republic of, 2MR Application Predevelopment, Siemens Healthcare, Erlangen, Germany, 3Application department, Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China, People's Republic of, 4MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China, People's Republic of |
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Histogram analysis of whole-liver ADC maps was applied for patients with liver fibrosis to assess its diagnostic value and correlation with fibrosis stages achieved from liver biopsy. Our study shows that the mean and the 75th percentile ADC were significantly lower with the increasing grade of liver fibrosis. The median, standard deviation (SD), 5th, 10th, 25th, 90th and 95th percentiles also showed statistical differences among pathological fibrosis grades. In conclusion, histogram analysis of whole-liver ADC maps has a potential value for quantifying liver fibrosis grades. |
| 2949 | Computer #39 |
Conspicuity of malignant liver tumors on STIR low b diffusion-weighted imaging with gadolinium ethoxybenzyl dethylenetriaminepentaacetic acid |
1Department of Radiological Technology, Kagoshima University Hospital, Kagoshima, Japan, 2Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan |
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When liver MRI is performed using Gd-EOB-DTPA, DWI is often obtained after Gd-EOB-DTPA injection to shorten examination time in the busy clinical practice. We compared malignant tumor conspicuity on low b-value DWI after contrast between chemical shift selective (CHESS) and short inversion time inversion recovery (STIR) sequences. Malignant liver tumors were more conspicuous with STIR than with CHESS. DWI with STIR is useful for visualizing malignant liver tumors after Gd-EOB-DTPA injection, thus decreasing overall scan time. |
| 2950 | Computer #40 |
Non-uniformity correction of Gd-EOB-DTPA-enhanced magnetic resonance imaging of the liver at 3T |
1Kitasato University School of Medicine, Sagamihara, Japan, 2Kitasato University Hospital, Sagamihara, Japan |
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We evaluated two commercially available methods for non-uniformity correction, an image-based method (SCIC) and a calibration-based method (PURE), in Gd-EOB-DTPA-enhanced MR imaging using a 3T scanner. SCIC improved uniformity for the precontrast images; however, artificial hyperintensity in the liver surface was evident especially in the hepatobiliary-phase images. Quantitative evaluation of contrast effects were severely distorted by SCIC. PURE improved uniformity in the precontrast and hepatobiliary-phase images, and appeared to aid quantitative evaluation of the signal intensity after contrast administration. PURE is indicated to be a useful non-uniformity correction method in Gd-EOB-DTPA-enhanced MR imaging using a 3T scanner. |
| 2951 | Computer #41 |
Noninvasive MR diffusion and perfusion analysis of liver fibrosis using comprehensive parameters |
1Radiology, Tianjin First Center Hospital, Tianjin, China, People's Republic of, 2Philips healthcare, Beijing, China, People's Republic of |
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This study investigated the value of multi-parametric analysis using MR IVIM, BOLD MRI and DKI for the diagnosis of liver fibrosis. Eight patients with clinically diagnosed liver fibrosis and thirteen healthy control subjects were scanned with DKI, IVIM, BOLD. IVIM derived D*, D, f, DKI derived MD, K value and BOLD derived R2* were compared between the two groups. Our results showed D*, D, f, MD decreased, R2* and K value increased in patients with liver fibrosis, but only D* and D demonstrated significant difference (P<0.05). We therefore conclude D* and D could be useful in the diagnosis of liver fibrosis. |
| 2952 | Computer #42 |
Robust free-breathing hepatic MRI using respiratory-gated 3D stack-of-stars sequence |
1radiology, Tokyo metropolitan police hospital, Tokyo, Japan, 2Graduate school of Medicine, Tohoku university, Miyagi, Japan, 3Marketing, Philips Electronics Japan, Tokyo, Japan, 4Division of Diagnostic Image Analysis, Graduate school of Medicine, Tohoku University, Miyagi, Japan |
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A extend of slice direction and high resolution imaging cannot help to increase scan time in hepatic MRI. The hepatic MRI is necessary to hold their breath, and breath holding influenced on image quality. Hence improved image quality on hepatic MRI is a required free breath sequence. Our study using 3D stack-of-stars trajectory with respiratory navigator is objective that perfectly eliminate respiratory motion effect. A sequence combined motion averaging by stack-of-stars and correction by navigator is possible to eliminate respiratory motion. |
| 2953 | Computer #43 |
Liver MR imaging using 3D phase-sensitive inversion recovery (PSIR) sequence |
1Department of Medical Imaging, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan, 2Radiological Center, National Hospital Organization Kumamoto Medical Center, Kumamoto, Japan, 3Department of Radiology, University of Fukui, Fukui, Japan, 4Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, Ibaraki, Japan |
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We applied 3D phase-sensitive inversion recovery (PSIR) sequence to liver MR imaging. Experiments with phantom and healthy subjects revealed that this sequence improved contrast enhancements of Gd-based agents and liver-to-spleen or muscle contrasts while simultaneously providing an accurate T1 map of the liver. Better Gd contrast enhancements and liver contrasts may improve tumor-to-liver contrasts in the hepato-biliary phase with Gd-based hepatocyte-specific contrast agents, and the accurate T1 map may be useful for liver-function assessments. Although a clinical study is required to evaluate its utility, this sequence may have potential to improve liver MR imaging. |
| 2954 | Computer #44 |
Reducing bias due to B0 inhomogeneity in abdominal T2* mapping |
1Radiology Department, New York University School of Medicine, New York, NY, United States |
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T2* measurements in the abdomen are often corrupted by macroscopic magnetic susceptibility effects from air in the lung and bowel. We show that sensitivity to linear B0 variations can be eliminated by tailoring the 2D slice profile appropriately and truncating the echo train where the phase difference between adjacent voxels within or across slices exceeds $$$\pi/2$$$. This improves T2* accuracy without the need for post hoc corrections. When compared with a conventional approach, the proposed technique demonstrates reduced sensitivity to B0 inhomogeneity in the liver caused by magnetic susceptibility differences in the lung. |
| 2955 | Computer #45 |
Comparison of Three Different DiffusionWeighted Imaging Acquisitions for Focal Liver Lesions |
1Department Of Imaging Diagnosis,Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing China, Beijing, China, People's Republic of, 2GE Healthcare, MR Research China, Beijing, Beijing, China, People's Republic of |
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By comparing the breath-hold, respiratory-triggered, and free-breathing techniques in diffusion-weighted magnetic resonance imaging (MRI) for the evaluation of focal liver lesions on a 3.0T system, we found that: The free-breathing DWI is better than others for the patients who want to do the whole liver examination; but for the patients with focal liver lesions who need to do the DWI scan to evaluate the local lesions, the breath-hold DWI was optimal. Generally speaking, the respiratory-triggered DWI of the 3T MRI system had higher SNR and CNR in any case, and it was the best DWI acquisition technique. |
| 2956 | Computer #46 |
Effects of ancillary features of gadoxetic acid-enhanced MRI on the categorization of hepatocellular carcinoma: validation of the Liver Imaging Reporting And Data System v2014 |
1Radiology, Seoul National University Hospital, Seoul, Korea, Republic of, 2Radiology, Chung-Ang University Hospital, Seoul, Korea, Republic of |
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The latest Liver Imaging Reporting And Data System (LI-RADS v2014) incorporates gadoxetic acid-enhanced MRI into the diagnostic algorithm of hepatocellular carcinoma (HCC). In this study, we investigated the effects of ancillary features of gadoxetic acid-enhanced MRI in the determination of LI-RADS categories of HCCs. On gadoxetic acid-enhanced MRI, LI-RADS showed sensitivities of 69.0% and 67.8% in the diagnosis of HCCs (LR-5/5v) in two reviewers, respectively. Ancillary features of HCCs on gadoxetic acid-enhanced MRI including hepatobiliary imaging features frequently resulted in upgrade LR-3 to LR-4. |
| 2957 | Computer #47 |
Use of Intravoxel Incoherent Motion (IVIM) in Evaluation of Histological Differentiation of Hepatocellular Carcinoma (HCC) in Patients with Hepatitis B Virus Infection |
1Department of Radiology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China, People's Republic of, 2GE Healthcare China, Beijing, China, People's Republic of, 3Mayo Clinic, Rochester, MN, United States |
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Among the various causes of hepatocellular carcinoma (HCC), hepatitis B virus (HBV) infection is the most common one in Asian countries including China. We assessed the correlation of ADC and IVIM parameters with the histological differentiation of HBV-related HCCs. Our results showed that ADC, D and f coefficients are significantly correlated with histological differentiation of HBV-related HCC. According to ROC analysis, ADC, D and f were useful parameters for the evaluation of histological differentiation of HCCs. ADC showed better diagnostic performance compared with D and f IVIM is a promising tool for predicting histological differentiation of HBV-related HCC. |
| 2958 | Computer #48 |
Short-Term Reproducibility of Intravoxel Incoherent Motion Parameters and Apparent Diffusion Coefficient of Large Hepatocellular Carcinoma |
1Fudan University, Shanghai, China, People's Republic of |
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More and more studies have been attributed to the evaluation of IVIM analysis for disease characterization or response assessment, but its measurement reproducibility when applied in clinical practice and research still be in controversial. There is only few prior research on repeatability of IVIM-derived parameters of hepatocellular carcinoma (HCC) as well as the choice of free-breathing (FB). In this study we used our own data to explore the reproducibility of IVIM-derived parameters, ADC(0,500) and ADCtotal of HCC. |
| Exhibition Hall | Monday, May 9, 2016: 15:15 - 16:15 |
| 2959 | Computer #49 |
Correlation of Pre –Treatment Volumetric Apparent Diffusion Coefficient Histogram Analysis of Diffusion Weighted MRI in Rectal Cancer with Post ChemoRadiation Treatment Response and Clinical Outcomes. |
1UHN,university of Toronto, Toronto, ON, Canada, 2Royal Liverpool Hospital, Liverpool, United Kingdom, 3Toronto, Canada, 4Mt.Sinai Hospital,University of Toronto, Toronto, Canada |
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Rectal cancer patients treated with preoperative chemoradiation therapy with complete treatment response can be considered for individualised therapies such as ‘wait and watch’ avoiding surgery. However this currently can only be definitely identified by postoperative histopathology. Diffusion weighted-MRI has been well correlated to tumor biology and treatment response. Volumetric ADC histogram analysis eliminates errors resulting from tumor heterogeneity and variable diffusivities by including the tumor volume and could provide promise for prediction of treatment response and clinical outcomes,thereby providing means for individualised therapy. |
| 2960 | Computer #50 |
Correlation between apparent diffusion coefficients and HER2 status in gastric cancers: pilot study |
1Department of Radiology, Drum Tower Hospital, School of Medicine, Nanjing University, Nanjing, China, People's Republic of, 2Philips Healthcare Greater China, Shanghai, China, People's Republic of |
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Forty-five patients with gastric cancer underwent DWI prior to surgery to evaluate whether ADC value correlates with the HER2 status. HER2 status was compared among tumors with various histopathological features. Meanwhile, the ADC values of gastric cancers with positive and negative HER2 were compared. The mean ADC value of HER2-positive gastric cancers was significantly higher than those of HER2-negative tumors. The minimal ADC value of HER2-positive gastric cancers was significantly higher than those of HER2-negative tumors. The ADC values of gastric cancer correlate with the HER2 status. DWI can predict HER2 status and help in tailoring therapy for gastric cancer. |
| 2961 | Computer #51 |
Spatial registration improves parametric mapping of abdominal MRI and may allow assessment of extent of fibrosis in intestinal lesions of patients with Crohn’s Disease |
1Genentech Inc., South San Francisco, CA, United States |
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Parametric mapping may provide estimates of extent of fibrosis in Crohn’s Disease (CD) patients but are subject to respiratory and peristaltic motion. Various image registration strategies and their impact on quality and robustness of parametric maps of gain of enhancement (GE) and magnetization transfer ratio (MTR) were compared. Healthy test-retest and CD image datasets were evaluated. Spatial registration improved quality and test-retest reliability of GE and MTR maps. In a limited cohort, extent of fibrosis estimated with GE and MTR maps were correlated. Cross validation of MR enterography-based fibrosis estimates with histological data will be conducted as data becomes available. |
| 2962 | Computer #52 |
Prospective Comparison of a Contrast-Enhanced MRI Protocol with Contrast-Enhanced CT for the Primary Diagnosis of Acute Appendicitis |
1Emergency Medicine, University of Wisconsin - Madison, Madison, WI, United States, 2Radiology, University of Wisconsin - Madison, Madison, WI, United States, 3Biostatistics and Medical Informatics, University of Wisconsin - Madison, Madison, WI, United States |
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The aim of our study was to determine the test characteristics of an MRI protocol consisting of unenhanced, contrast-enhanced, and DWI to diagnose appendicitis. This was a prospective study including patients ≥12 years old being evaluated for appendicitis. We enrolled 226 patients; all images were interpreted by three fellowship-trained abdominal radiologists. Sensitivity and specificity (95% CI) were 95.2% (86.5-99%) and 89.4% (83.2-94%) for unenhanced MRI with DWI, 96.8% (89-99.6%) and 89.9% (83.7-94.4%) for CE-MRI, and 98.4% (91.6-100%) and 93.7% (88.3-97.1%) for CE-CT. We conclude that this MRI protocol is as accurate as CE-CT to diagnose appendicitis. |
| 2963 | Computer #53 |
Assessment of flow in the human colon in health and constipation using an MR tagging technique |
1Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, 2Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, United Kingdom, 3Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, United Kingdom |
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Assessment of colonic motility may be extremely useful in understanding the symptoms of constipation. Current techniques (manometry, cine-MRI) can only detect wall movements and not the effect this motion may have on mixing of colonic contents. We report the use of an MR tagging technique to assess flow and mixing in the human colon following ingestion of a 500ml macrogol preparation. This technique successfully identified differences in intracolonic mixing between 11 healthy and 11 constipated subjects and shows potential to generate novel insights into the physiology and mechanisms of disease and the environmental pressures on, and effects of, gut microbiota. |
| 2964 | Computer #54 |
Perfusion and Diffusion Weighted Magnetic Resonance Imaging in Rectal cancer: How is the Correlation between Multiple Methods? |
1Department of Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China, People's Republic of, 2MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China, People's Republic of |
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DCE-MRI, IVIM and DKI are emerging as promising tools for tumor diagnositic or therapy-predictive purposes. We performed these three methods in patients with rectal cancer simultaneously to find out their correlations. Our results showed significant correlation between perfusion sensitive parameters of IVIM and DCE-MRI. In addition, DKI parameters were calculated from data with a low (0-1000) and high (200-2000) b-value range, and the parameters from low b-value range showed significant correlation with IVIM parameters, but not for the high b-value range. |
| 2965 | Computer #55 |
Radiomic Features on Diagnostic Magnetic Resonance Enterography Appear to Predict Patient Outcome Following Treatment of Crohn’s Disease: Preliminary Results |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Digestive Health Institute, University Hospital, Case Western Reserve University, Cleveland, OH, United States, 3Dept of Radiology, University Hospital, Case Western Reserve University, Cleveland, OH, United States |
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We present initial results of identifying radiomic features (computer-extracted image features from radiography) from baseline diagnostic Magnetic Resonance Enterography (MRE) scans to discriminate patients who will and will not respond to initial therapy for Crohn’s Disease. Feature selection was employed to identify the most discriminatory features, followed by principal component analysis to identify an optimal combination of these features. In a cohort of 11 patients, the radiomic feature combination was able to successfully distinguish between responders and non-responders with only 1 misclassification. Multi-scale oriented gradient (Gabor) features appeared to best capture subtle inflammation-related imaging characteristics on MRE and hence most predictive of patient outcome. |
| 2966 | Computer #56 |
Application of Magnetic Resonance Fingerprinting (MRF) for assessment of rectal cancer: a feasibility study |
1Radiology, Case Western Reserve University, Cleveland, OH, United States, 2Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 3Hematology and Oncology, University Hospitals Case Medical Center, Cleveland, OH, United States, 4Radiology and Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 5Radiology, University Hospitals Case Medical Center, Cleveland, OH, United States |
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Accurate delineation of tumor extent and early assessment of response to treatment are open challenges in imaging evaluation of colorectal tumors. Quantitative imaging methods as relaxometry have been explored to fulfill this unmet need, but not adopted in clinical practice due to long acquisition time. In this feasibility study, we examined the relaxation time of rectal tumors, mesorectum and rectal wall using magnetic resonance fingerprinting (MRF) |
| 2967 | Computer #57 |
Volumetric dynamic MR-defecography |
1Institute of Diagnostic and Interventional Radiology, Unisversity Hospital Würzburg, Würzburg, Germany, 2Institute of Mathematics, University Würzburg, Würzburg, Germany, 3Department of General-, Visceral-, Vascular- and Pediatric Surgery, Unisversity Hospital Würzburg, Würzburg, Germany |
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Current 2D MR-defecography techniques lack information about lateral localized pathologies. The purpose of this project was to implement a dynamic 3D MR-defecography which covers a larger area and thereby gathers more detailed information on the anatomy during defecation. Therefore we implemented a radial 3D TrueFISP Stack of Stars sequence with density-weighting and view-sharing. The highly undersampled datasets, which we have acquired in 5 patients, were reconstructed using a modified FISTA compressed sensing algorithm. The proposed method allows for a dynamic 3D examination of the fast defecation process. Therefore the detection of lateral localized pathologies is possible as well. |
| 2968 | Computer #58 |
Use of magnetic resonance imaging to assess the effects of corticotrophin releasing factor on fructose malabsorption |
1Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom, 2NIHR Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, United Kingdom, 3University of Nottingham, Nottingham, United Kingdom |
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A link between FODMAP malabsorption and stress has been suggested. Here, the effects of corticotrophin releasing factor (CRF) on fructose malabsorption are investigated in this randomised, placebo-controlled, crossover study in healthy volunteers. |
| 2969 | Computer #59 |
Compressed Sensing and Parallel Imaging (CS-PI) Reconstruction of Prospectively Undersampled Dynamic MRI for Faster Imaging of Bowel Motility |
1Radiology Department, 3T Lab, Academic Medical Center, Amsterdam, Netherlands |
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Motility assessment of the small bowel using dynamic MRI can only be acquired with either a limited coverage of the intestines or relatively low temporal resolution, which obscures details of motion during contraction and relaxation. Compressed sensing and parallel imaging (CS-PI) techniques allow higher temporal resolution imaging by acquiring and reconstructing undersampled acquisitions. In this abstract we show that by using CS-PI, accelerations up to 7X could be achieved, which outperforms conventional approaches based on parallel imaging only. As a consequence, CS-PI provides a valuable tool for improved assessment of small bowel motility. |
| 2970 | Computer #60 |
R2* estimation with CSI: A Pilot and Feasibility Study |
1Biomedical Engineering, University of Southern California, Sierra Madre, CA, United States, 2Philips Healthcare, Cleveland, OH, United States, 3Electrical Engineering, University of Southern California, Los Angeles, CA, United States, 4Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, 5Cardiology, Children's Hospital of Los Angeles, Los Angeles, CA, United States |
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R2 (1/T2) and R2* (1/T2*) are useful metrics related to tissue iron loads. Clinical iron estimation at 3T is limited by the achievable echo times in Cartesian spin echo and gradient echo imaging. We present a modified CSI spectroscopy sequence robust to motion for high SNR liver R2* estimation with the potential for simultaneous R2 estimation. |
| 2971 | Computer #61 |
Correlation between intravoxel incoherent motion (IVIM) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters in rectal cancer |
1Radiology, China-Japan Friendship hospital, Beijing, China, People's Republic of, 2Philips Healthcare China, Beijing, China, People's Republic of |
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Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has been applied in rectal cancer for the purpose of characterizing tumor perfusion[1]. However, DCE-MRI should use intravenous contrast media based gadolinium, which will increase the risk of kidney systemic fibrosis[2]. The bi-exponential analysis in intravoxel incoherent motion (IVIM) model can separate microscopic circulation perfusion with pure water diffusion[3-4]. Correlation has been derived between the IVIM perfusion parameters f and D* and the classical perfusion parameters[5-6]. However, its relationship with DCE-MRI parameters in rectal cancer has not been clarified. |
| 2972 | Computer #62 |
Simple improvement method of uniformity of MR elastography on liver |
1Tokushima University, Tokushima, Japan, 2School of Health Sciences, Tokushima University, Tokushima, Japan, 3MR Applications and Workflow, Asia Pacific GE Healthcare Japan Corporation, Hino, Japan, 4Department of Radiology and Radiation Oncology, Tokushima University, Tokushima, Japan |
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The purpose of this study was to development and evaluate a dual passive driver system to improve non-uniformity of liver MRE. This study was performed using a phantom and a volunteer. The standard deviation on unwrapped phase image (S.D.unwrap) for the dual driver system has shown higher values than that of a single system. Moreover, the shear stiffness value of a system having a high S.D.unwrap showed the highest correlation with actual measurement values (P < .05). In conclusion, MRE with a dual driver system may render it possible to obtain more detailed information for the evaluation of liver conditions. |
| 2973 | Computer #63 |
Contrast-Enhanced Perianal Fistula Imaging with Dixon-Based Fat Suppression |
1Radiology, Mayo Clinic, Rochester, MN, United States |
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Perianal fistula images with high spatial resolution, high SNR, and excellent fat suppression were achieved with a multi-TE interleaved acquisition and a constrained-phase graph cuts-based Dixon fat/water separation. |
| 2974 | Computer #64 |
FDG-PET-MR acquisition in systemic sclerosis for the assessment of gastrointestinal involvement: a pilot study |
1Clinical Imaging Research Centre, NUS, Singapore, Singapore, 2Departement of Rheumatology and Immunology, SGH, Singapore, Singapore, 3Duke-National University, Singapore, Singapore, 4Department of Gastroenterology and Hepatology, SGH, Singapore, Singapore |
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Systemic sclerosis (SSc) is a multi-system disease characterized by immune dysregulation, fibrosis and vascular damage that affects the gastrointestinal tract in most patients. In this study, we investigate simultaneous FDG-PET/MR imaging for the diagnosis of SSc GIT involvement. Our preliminary results show that FDG-PET can detect inflammation in the bowels while T1 MOLLI mapping could be able to distinguish healthy from fibrotic GIT tissue. |
| 2975 | Computer #65 |
Rectal Cancer: Apparent Diffusion Coefficient Value and Clinical-Pathologic Factors Associated with Local Recurrence or Distant Metastases |
1Radiology, Gifu University Hospital, Gifu, Japan, 2Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, United States |
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To determine the ADC value and clinical-pathologic risk factors associated with postoperative local recurrence or distant metastases in patients with rectal cancer. The plasmatic CA19-9 level (P = 0.0027), pathological N stage (P = 0.0018), lymphatic invasion (P < 0.0001), and ADC value (P = 0.0076) were independently associated with postoperative local recurrence or distant metastases in the patients with rectal cancer. Among the several indicators, the tumor ADC values and plasmatic CA19-9 level can be useful for the preoperative prediction of high risk cases for postoperative local recurrence or distant metastases in patients with rectal cancer. |
| 2976 | Computer #66 |
Assessing mucosal inflammation in a DSS-induced colitis mouse model by MR Colonography |
1Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel, 2Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel, 3Biomedical Magnetic Resonance Laboratory, Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO, United States |
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Inflammatory bowel disease (IBD) is characterized by uncontrolled inflammation of the gastrointestinal tract [1]. Determining the inflammatory state of the colon is critical for defining the disease activity. Endoscopy in human IBD allows visualization of mucosal inflammation [2]. However, the technique is based on grading of the entire colon, which is operator dependent. The mucosa is very fragile, therefore endoscopic evolution is problematic. Therefore, the development of an improved, noninvasive, objective MRI technique may provide a non-invasive assessment tool to depict pathologies in the small intestinal mucosa and, more specifically, along the colon, and to assess the bowel wall and surrounding structures. In this study, dextran sodium sulphate (DSS) polymer treatment was used to induce acute colitis in mice that was subsequently characterized by multi-slice MR colonography. |
| 2977 | Computer #67 |
Application of variable refocusing flip angle SSFSE T2 for improved MR Enterography in Pediatric Patients |
1Department of Radiology, University of California San Francisco, San Francisco, CA, United States, 2Global MR Applications and Workflow, GE Healthcare, Rochester, MN, United States, 3Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States, 4Global MR Applications and Workflow, GE Healthcare, Houston, TX, United States |
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MR enterography is the modality of choice for the imaging of inflammatory bowel disease, but presents unique challenges in the pediatric population, particularly with respect to motion degradation. Variable refocusing flip angle single shot fast spin echo (vrfSSFSE), an improvement upon the traditional single shot fast spin echo (SSFSE) sequence, allows for shortened acquisition times and improved contrast and spatial resolution. Clinical use of vrfSSFSE in pediatric MR enterography has led to subjective improvements in image quality and has allowed for improved identification of many imaging findings related to inflammatory bowel disease. |
| 2978 | Computer #68 |
Evaluation of bSSFP for the visualisation of Human fetal esophageal and tracheal obstruction and swallowing |
1Medical Physics, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom, 2Academic Unit of reproductive and developmental medicine, University of Sheffield, Sheffield, United Kingdom |
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A balanced steady-state free precession (bSSFP) sequence gives excellent fluid/tissue contrast and allows rapid repeat acquisition of a single slice, resulting in a cine image dataset. We evaluate the bSSFP sequence to image fetal swallowing action and passage of fluid in the esophagus and airway in 7 human fetuses. Regurgitation of amniotic fluid is observed where major or total obstruction is present. Optimised bSSFP sequences are demonstrated at 1.5T and 3.0T and can be used in assessment of obstruction and swallowing in a wide variety of cases including esophageal atresia, neck masses, CHAOS and cleft palate. |
| 2979 | Computer #69 |
Correcting for the Effect of Motion using Simultaneous Image Registration and Model Estimation (SIR-ME) in Abdominal DW-MRI |
1Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States, 2Nuclear Medicine, Rabin Medical Center, Petah-Tikva, Israel |
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Quantitative diffusion-weighted MRI (DW-MRI) has been increasingly used for the detection and characterization of abdominal abnormalities. However, respiratory, cardiac and peristalsis motion deteriorates robustness and reproducibility of parameter estimation in DW-MRI. Current solutions do not entirely correct for motion and have disadvantages such as increased scan time. In this work, we introduce a simultaneous image registration and model estimation (SIR-ME) framework for motion-compensated parameter estimation. The proposed method improved the goodness-of-fit by more than 50% and estimated model parameters more precisely, resulting in better discrimination between normal and diseased bowel loops, which will potentially impact clinical utilization. |
| 2980 | Computer #70 |
DWIBS Improves the Detection of Extra-Hepatic Colorectal Cancer Metastases. A Prospective Study. |
1Department of Radiology, Aarhus University Hospital, Aarhus, Denmark, 2Department of Oncology, Aarhus University Hospital, Aarhus, Denmark, 3PET-centre, Aarhus University Hospital, Aarhus, Denmark |
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A whole body (WB) MRI protocol added to a dedicated liver MRI in one scan session, could alleviate the need for a PET/CT for staging patients prior to local treatment of colorectal liver metastases. With the aim of developing a disease optimised WB protocol, 30 patients with extra-hepatic metastases from colorectal cancer were prospectively recruited and scanned on a 1.5 T scanner and using a PET/CT scan within an average of 1.33 days as reference. Preliminary results show that combining a traditional whole body MRI protocol with DWIBS produces superior results compared to the traditional protocol alone. |
| 2981 | Computer #71 |
Dynamic multi-echo MRI of rectal cancer: Quantitative tumor R2* analysis predicts lymph node status |
1The Intervention Centre, Oslo University Hospital, Oslo, Norway, 2Department of Physics, University of Oslo, Oslo, Norway, 3Department of Oncology, Akershus University Hospital, Lørenskog, Norway, 4Faculty of Medicine, University of Oslo, Oslo, Norway, 5Department of Radiology, Akershus University Hospital, Lørenskog, Norway, 6Sunnmøre MR klinikk AS, Ålesund, Norway |
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The purpose was to evaluate the association between the dynamic change in R2*, obtained from a multi-echo dynamic contrast-based acquisition, and clinicopathologic data in patients with rectal cancer. Twenty patients were examined using a high temporal resolution multi-echo EPI sequence. Dynamic R2* images were calculated by assuming a mono-exponential dependence of signal change on echo-time, and parametric images representing the maximum peak change in R2*, ΔR2*-peak, were generated. Tumor ΔR2*-peak significantly differentiate between rectal cancer patients with and without nodal metastases (P=0.01), with an area under the ROC curve of 0.94. |
| Exhibition Hall | Monday, May 9, 2016: 15:15 - 16:15 |
| 2982 | Computer #73 |
Spectral analysis enhances the detectability of rotary saturation contrast |
1Center for MRI Research, Peking University, Beijing, China, People's Republic of, 2GE Healthcare MR Research China, Beijing, China, People's Republic of |
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Traditional rotary saturation based methods requires triggered phases to create a robust signal change, which may not be satisfied in practical application. In this work, based on the analysis of magnetization in the double rotating frame, we proposed detecting the signal fluctuations of proposed SLOE method by manipulating TRs, which needs no triggering. Further, a spectral statistical test in the frequency domain was proposed and verified, which featured an enhanced detection sensitivity than that of deviation test. |
| 2983 | Computer #74 |
QUANTITATIVE SUSCEPTIBILITY MAPPING OF THE LIVER AND SPLEEN IN SUBJECTS WITH FERUMOXYTOL INJECTION |
1Radiology, University of Wisconsin - Madison, Madison, WI, United States, 2Radiology, University of Yamanashi, Yamanashi, Japan, 3Medical Physics, University of Wisconsin-Madison, Madison, WI, United States |
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Ferumoxytol is an ultrasmall superparamagnetic iron oxide (USPIO) agent that is taken up by the reticuloendothelial system where it accumulates in organs such as the liver, spleen, and bone marrow. Given the superparamagnetic properties of ferumoxytol, it may be possible for quantitative susceptibility mapping (QSM) techniques to detect and quantify the concentration of ferumoxytol in these organs. Recent technical developments have demonstrated the feasibility of a QSM technique for magnetic susceptibility mapping of the abdomen. Thus, the purpose of this work was to test the feasibility of QSM to assess the longitudinal changes of ferumoxytol in the liver and spleen. |
| 2984 | Computer #75 |
Contrast-Enhanced Susceptibility Weighted Imaging with Ultrasmall Superparamagnetic Iron Oxide Improves the Detection of Tumour Vascularity in A HCC-LM3 Nude Mouse Model |
1Radiology, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai, China, People's Republic of, 2Radiology, Shuguang Hosipital, Shanghai University of Traditional Chinese Medicine, Shanghai, China, People's Republic of, 3Pathology, Shuguang Hosipital, Shanghai University of Traditional Chinese Medicine, Shanghai, China, People's Republic of, 4Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China, People's Republic of |
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Hepatocellular carcinoma (HCC) is a hyper-vascular tumor and knowledge of the intratumoral vascularity is essential. Susceptibility weighted imaging (SWI) uses magnitude and filtered-phase information to provide high sensitivity to susceptibility changes caused by hemorrhage, calcium, iron, and small veins. It has been used to visualize normal or pathologic vascular structures that are not visible on conventional MRI. Ultrasmall superparamagnetic iron oxide (USPIO) is an intravascular blood pool contrast medium. After intravenous administration, it can cause a greater effect on local magnetic field inhomogeneities and results in higher susceptibility differences between all intratumoral vessels and the tumor on SWI. This study showed that USPIO-enhanced SWI could further enhance the demonstration of tumor vascularity inside HCC when compared to unenhanced SWI in an orthotopic xenograft nude mice HCC model. |
| 2985 | Computer #76 |
Using frequency difference mapping to assess white matter microstructure in the human corpus callosum |
1Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom |
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Frequency difference mapping (FDM) is a recently developed phase-based technique that takes advantage of the non-linear temporal evolution of the phase in GE sequences to produce images that are sensitive to white matter microstructure. Images can be produced simply from raw phase data, with minimal post-processing. In this study 10 subjects underwent six repeats of a single-slice, sagittal multi-echo GE scan on the mid-line. Frequency difference maps reproducibly depicted white matter tracts oriented perpendicular to the applied field. Fitting the FD and magnitude data to a three-pool model provided insight into the variation of microstructure along the corpus callosum. |
| 2986 | Computer #77 |
Can myelin protons be directly imaged with the adiabatic inversion recovery prepared ultrashort echo time (IR-UTE) sequence - a validation study based on D2O exchange in sheep brain specimens |
1Radiology, University of California, San Diego, San Diego, CA, United States |
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Directly assessing the integrity of myelin in white matter is important for diagnosis and assessment of prognosis in multiple sclerosis (MS). However, the protons in myelin have extremely short T2s and cannot be directly imaged with conventional clinical MRI sequences. Adiabatic inversion recovery prepared ultrashort echo time (IR-UTE) sequences can detect signal from myelin protons and efficiently suppress the signal from water. In this study we aimed to further validate the IR-UTE technique in sheep brain using a D2O exchange model. |
| 2987 | Computer #78 |
Phase Correction of a Bipolar Gradient-Echo Acquisition for Quantitative Susceptibility Mapping |
1University of Calgary, Calgary, AB, Canada |
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A method to remove phase offsets in bipolar gradient-echo readouts is proposed. Their effects on Quantitative Susceptibility Mapping (QSM) reconstruction are demonstrated by comparing QSM before and after phase offsets removal. |
| 2988 | Computer #79 |
High Resolution Blood Vessel Imaging with USPIOs in the Human Brain: T1 vs T2* contrast. |
1Radiology, Stanford University, Palo Alto, CA, United States, 2Neurosurgery, Stanford University, Stanford, CA, United States |
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In this study, we probed the potential of ultrasmall superparamagnetic iron oxide particles (USPIOs) to provide high-resolution angiographic images of the human brain using T2* and T1 contrasts. 10 paediatric patients suspected of arteriovenous malformations (AVM) were scanned pre and post intravenous USPIOs injection as part of their clinical exam. To test the influence of USPIOs concentration on both T2* and T1 images, a healthy volunteer was scanned before and after injections of 7 incremental doses of the contrast agent. The results suggest that both approaches can provide exquisite details of the neurovascular anatomy while offering complementary information. |
| 2989 | Computer #80 |
Artifacts Affecting Derivative of $$$B_1^+$$$ maps for EPT Reconstructions |
1Center For Image Sciences, UMC Utrecht, Utrecht, Netherlands |
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EPT conductivity reconstruction is affected by difficulties to reliably calculate spatial derivatives on voxelized MRI data. Here, we explore the impact of several numerical approximations. In particular: the different size of finite-difference kernels and the k-space truncation (always present in MR images). We also explore a Fourier-domain alternative, which does not require finite-difference approximation kernels. |
| 2990 | Computer #81 |
Comparison of Multi-transmit Microstrips and Loops for Electrical Properties Tomography (EPT) in the Breast at 3T |
1Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States, 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 3Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN, United States |
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Electrical Properties Tomography (EPT) is a promising technique to provide high specificity in breast cancer diagnosis. Previous studies have demonstrated that multi-transmit coils array enables reconstruction of the electrical properties free of transmit phase and local homogeneity assumptions. In this study, the strengths and drawbacks of a microstrip array and a loop array for EPT reconstruction in the breast at 3T were investigated based on numerical simulations. It has been discovered that with the same driving power, a loop array provides higher signal to noise ratio on the reconstructed image while a microstrip array performs better at delineating tissue boundaries. |
| 2991 | Computer #82 |
Generalized Phase based Electrical Conductivity Imaging |
1Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey |
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In this study, a new formulation for phase based electrical properties tomography (EPT) has been proposed to eliminate the boundary artifact issue and to provide robustness against noise. The feasibility of the proposed method, which is called "generalized phase based EPT", has been demonstrated using simulation, experimental phantom, and in vivo experiments. |
| 2992 | Computer #83 |
Applying „Electric Properties Tomography“ to Low Frequency Conductivity Using Magnetic Particle Imaging |
1Philips Research Europe, Hamburg, Germany |
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MRI-based “Electric Properties Tomography” (MRI-EPT) determines electric conductivity measuring and post-processing the spatial distribution of the TX RF field. Obtained conductivity corresponds to Larmor frequency, reflecting biochemical content of tissue, but not its specific cellular structure. Cellular tissue structure is reflected by conductivity at low frequency (LF, 100-500 kHz), as used for “Magnetic Particle Imaging” (MPI). Similar to MRI, MPI is able to determine the spatial distribution of applied LF field, and thus, a reconstruction of LF conductivity should be possible (“MPI-EPT”) in analogy to MRI-EPT. This study investigated the principle feasibility of MPI-EPT and compared results with MRI-EPT. |
| 2993 | Computer #84 |
Global Maxwell Tomography: a novel technique for electrical properties mapping without symmetry assumptions or edge artifacts |
1Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, United States, 2Center for Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow, Russian Federation, 3Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, 4The Sackler Institute of Graduate Biomedical Science, New York University School of Medicine, New York, NY, United States |
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We introduce Global Maxwell Tomography (GMT), a novel volume integral equation-based technique for the extraction of electric properties from MR data. GMT is framed as an unconstrained optimization problem in which the error between measured and simulated B1+ magnitude maps is minimized. Due to its global nature, GMT is not subjected to edge artifacts. By using exclusively B1+ magnitude, GMT does not rely on symmetry assumptions to estimate B1+ phase. In one numerical example, three tumors were inserted into a head model, and starting from a tumorless initial guess, GMT accurately inferred the electrical properties and locations of these tumors. |
| 2994 | Computer #85 |
Application of Generalized Phase based Electrical Conductivity Imaging in the Subacute Stage of Hemorrhagic and Ischemic Strokes |
1Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey, 2Department of Neurology, Yıldırım Beyazıt University Atatürk Education and Research Hospital, Ankara, Turkey |
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In this study, clinical applicability of the recently proposed generalized phase based EPT method has been investigated for two patients with neurovascular diseases in the subacute phase, i.e. hemorrhagic and ischemic stroke. In the case of ischemia, conductivity was found to be increased in the lesion area. In the case of hematoma, although the conductivity of the surrounding edema region was found to be increased, the conductivity in the hematoma region itself was found to be similar to that of brain tissue. |
| 2995 | Computer #86 |
Investigation and Reduction of the Effects of Gibbs Ringing in SSFP Phase Based MR-EPT |
1Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey |
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Phase based MR-EPT methods mainly make use of the balanced SSFP since it is a fast MRI sequence. As SSFP sequence yields high magnitude contrast variations, Gibbs artifacts occur at tissue boundaries. This artifact manifests itself as phase spikes and oscillations at and near tissue boundaries respectively. The commonly used image enhancement methods, for reducing the ringing artifact, mainly focus on the magnitude images, leaving out the phase images. Throughout simulation and phantom experiment results, we investigate and propose a method for the reduction of the effect of ringing artifact on phase based MR-EPT studies. |
| 2996 | Computer #87 |
Validation study of water-content-assisted electrical properties tomography (wEPT) with an electrolyte protein phantom and B1 inhomogeneity consideration |
1Kyung Hee University, Suwon, Korea, Republic of |
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New MRI-based tissue electrical properties (EPs) mapping techniques had achieved higher accuracy and resolution increasing its chances to be used in several clinical applications. In this work, we describe a validation study for a technique called water-content-assisted electrical properties tomography (wEPT) based on in situ measurements of a brain-tissue-like phantom created by electrolytic protein solutions. The influence of inhomogeneous radiofrequency field distributions and its impact in wEPT reconstructions is also analyzed. Significant consistency between in vivo brain tissue estimations and phantom measurements was found, supporting the formalism and validity of wEPT for EPT studies. |
| 2997 | Computer #88 |
Peripheral Nerve Imaging using 2-point Dixon 3D Fast Spine Echo (CUBE-FLEX) with Flow-Saturation Preparation (FSP): Initial Feasibility Study |
1Hospital for Special Surgery, New York, NY, United States, 2GE Healthcare, Hino, Japan, 3GE Healthcare, New York, NY, United States |
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High-resolution MRI currently plays an important role in diagnostic management of peripheral nerve pathology. Peripheral nerves, however, pose particular imaging challenges that conventional sequences frequently cannot address. Their small size and oblique course between muscles and alongside vessels may inhibit reliable identification. We propose a 2-point Dixon fat/water separation 3D fast spin echo technique to achieve uniform fat suppression, combined with a flow-saturation prep pulse to suppress moving vascular spins to improve nerve visualization. The objective of this study was to assess the technique’s feasibility and potential diagnostic utility in evaluating peripheral nerves throughout the body. |
| 2998 | Computer #89 |
Enforcing a Physical Tissue Model for Partial Volume MR Fingerprinting |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Radiology, Case Western Reserve University, Cleveland, OH, United States |
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We present a method to compute fraction maps of tissue types using a subset of three dictionary entries chosen specifically for each individual, enforcing consistency with a physical tissue model. This approach removes erroneous partial volumes in the fraction maps, and reduces noise and distortions in T1, T2, and M0 maps. |
| 2999 | Computer #90 |
Continuously Adjustable Fat Suppression Image Contrast with one MRI Acquisition |
1Siemens Healthcare USA Inc., Malvern, PA, United States, 2Case Western Reserve Univisity, Cleveland, OH, United States |
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Fat suppression or saturation (FatSat) is widely used in MRI applications, which reduces the fat signal and preserves water signal for clinical diagnosis, enhancing potential pathological changes. Different degree of FatSat yields different image contrast. However, when radiologists read FatSat images, they have different contrast preferences. To provide such variable preferences is not trivial because it typically costs more imaging time to re-acquire another contrast of FatSat image by adjusting imaging parameters. This work presents an alternative approach to provide continuously adjustable image contrast of FatSat images with only one acquisition. |
| 3000 | Computer #91 |
Spin Echo Dynamics as Codes for Quantitative Imaging |
1Diagnostic Radiology, Yale University, New Haven, CT, United States |
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Recent work has highlighted the complicated and distinctive dynamics that shape the signal observed during an irregularly-spaced train of spin echoes. Here, we use those signals as codes that allows us to identify mixtures of molecules that are too similar to distinguish by standard spectroscopy. Extensions to water based systems, where relaxation mechanisms are the primary driver of signal dynamics, will also be presented. |
| 3001 | Computer #92 |
Dual-pathway sequences for MR thermometry: When and where to use them |
1Department of Biomedical Engineering, Akdeniz University, Antalya, Turkey, 2Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States, 3Department of Physics, Soochow University, Taipei, Taiwan |
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Dual-pathway sequences have been proposed to improve the temperature-to-noise-ratio (TNR) in MR thermometry. The present work establishes how much improvement these sequences may bring for various tissue types. Simulation results were validated against analytical equations, phantom and in vivo human results. PSIF-FISP thermometry allowed TNR improvements for kidney, pelvis, spleen or gray matter, and up to 2-3 fold reductions in TR with 20% TNR gains were achievable. Further TNR benefits are expected for heated tissues, due to heating-related changes in relaxation rates. In other tissue types such as liver, muscle or pancreas improvements were observed only for short TR settings. |
| 3002 | Computer #93 |
T2* Based MRI Temperature Contrast |
1UCCS Center for Biofrontiers Institute, University Colorado Colorado Springs, Colorado Springs, CO, United States, 2National Institute of Standards and Technology, Boulder, CO, United States |
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The aim of this study was to develop a novel temperature-sensitive MRI contrast agent based on temperature changes of the magnetic moment of magnetic particles. Gadolinium was used to test the hypothesis that magnetic particles will create a temperature-dependent local dipole magnetic field. This effect was locally visible as a temperature dependent darkening on gradient-echo MRI images. Shades of gray within the images can then be calibrated to map the local temperatures in specific areas of tissue during medical procedures. The estimated accuracy of temperature determination deep in the phantom using MR image intensity is ±1.8oC, at 37oC. |
| 3003 | Computer #94 |
Correlation time mapping of degenerated human and bovine articular cartilage reveals tissue structure and degenerative changes |
1Computer Science and Engineering, University of Oulu, Oulu, Finland, 2Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland, 3Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland, 4Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, 5Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, 6Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland |
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Correlation time ($$$\tau_c$$$) maps were obtained by fitting $$$\tau_c$$$ from $$$T_{1\rho}$$$ dispersion measurements of human articular cartilage specimens and enzymatically digested bovine samples to develop a new MRI contrast which characterizes tissue properties at molecular level. $$$\tau_c$$$ revealed the laminar appearance in control and PG depleted bovine specimens, which was not observable in the collagen-digested specimens. The laminar appearance was also visible in the early OA human specimens, in contrast to the advanced OA group. The results demonstrated that $$$\tau_c$$$ mapping is a potential method for providing information about the articular cartilage structure and associated changes with degeneration. |
| 3004 | Computer #95 |
Cardiac in vivo T1-Mapping with Novel Reactive Oxygen Species Sensing Agent Specifically Detects Cardiac Oxidative Stress in Doxorubicin-treated Rats |
1MRI Research Center, Auburn University, Auburn University, AL, United States, 2Chemistry & Biochemistry, Auburn University, Auburn University, AL, United States, 3Anatomy, Physiology and Pharmacology, Auburn University, Auburn University, AL, United States, 4MR R&D, Siemens Healthcare, Malvern, PA, United States, 5Chemistry and Biochemistry, Auburn University, Auburn University, AL, United States |
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Pathological cardiac oxidative stress causes cardiac dysfunction and possible cardiac failure. We developed a novel reactive oxygen species sensing T1 agent (H4qpt2) and applied it with in vivo cardiac T1 mapping MRI at 7T in a doxorubicin-treated (Dox) rat model. Cardiac T1 mapping with H4qpt2 specifically detected significantly shortened myocardial T1 in Dox rats while no change in T1 occurred in skeletal muscle or control rats with H4qpt2. This new H4qpt2 agent combined with cardiac or non-cardiac T1 mapping may advance the early detection of oxidative stress in multiple pathologies and promote their early treatment. |
| 3005 | Computer #96 |
Heteronuclear Proton MRI - SNR, temperature effects and frequency separation of UTE versus CSI readout |
1Department of Clinical Radiology, University of Münster, Münster, Germany |
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Heteronuclear proton MRI is a recent method for MRI cell tracking and opens up the possibility for Multicolor MRI when using different Ln-DOTMA complexes. Here, we compare UTE and CSI as readout with regard to SNR efficiency, sensitivity towards temperature changes and performance in separating resonance lines from different Ln-DOTMA complexes at 9.4 T. UTE readout provides faster image acquisition and higher SNR efficiency than CSI. CSI on the other hand is insensitive to temperature changes. Multicolor MRI was possible with both readout schemes. Further studies will use these methods for in vivo cell tracking experiments. |
| Exhibition Hall | Monday, May 9, 2016: 16:30 - 17:30 |
| 3006 | Computer #1 |
Imaging Restrictive Pore Geometry with Asymmetrical Chirped Pulses |
1Jordan University of Science and Technology, Irbid, Jordan, 2MGH, Boston, MA, United States, 3Harvard, Cambridge, MA, United States |
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Presents a practical way of recovering the phase of diffusing spins to recover the underlying restrictive geometry through a Fourier transform |
| 3007 | Computer #2 |
Enhanced efficiency and sensitivity in detection of acute ischemic brain injury using fast diffusion kurtosis imaging |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, 2Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Key Laboratory for MRI, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, People's Republic of, 3Department of Radiology, University of Illusions at Chicago, Chicago, IL, United States, 4Department of Radiology, Xiamen 2nd Hospital, Xiamen, China, People's Republic of |
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We systematically compare the diagnostic value of conventional tensor-based DKI and recently proposed fast DKI protocols using an acute stroke rodent model. The measures and volumes of diffusion and kurtosis lesions were in good agreement between the two DKI methods. Importantly, contrast-to-noise ratio (CNR) of mean kurtosis using the fast DKI protocol was significantly higher than that of the routine method with its CNR efficiency approximately doubles. Therefore, our results demonstrated excellent performance of the fast DKI protocol in characterizing acute ischemic tissue injury, which may facilitate translation of the fast DKI approach in the acute stroke setting. |
| 3008
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Computer #3 |
Towards Fast Diffusion-Sensitized MR Imaging of the Eye and Orbit with High Anatomic Fidelity: Combining a Segmented RARE variant with Inner Volume Imaging |
1Berlin Ultrahigh Field Facility (B.U.F.F), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany, 2Department of Ophthalmology, University Medicine Rostock, Rostock, Germany, 3Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany |
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Diffusion-weighted imaging of the eye and orbit is an emerging MRI application to provide guidance during diagnostic assessment and treatment of ophthalmological diseases. It has been shown that RARE based diffusion-sensitized imaging (ms-RARE) provides images free of geometric distortions. Though, artifacts induced by involuntary eye motion remain a concern. Applying inner volume imaging (IVI) offers the possibility to shorten acquisition times by reducing the number of acquired phase encoding lines. This study examines the applicability of IVI in conjunction with ms-RARE with the goal to reduce the propensity to bulk eye motion in diffusion-sensitized ophthalmic imaging. |
| 3009 | Computer #4 |
Impact of sequence parameters on the sensitivity of DDE and DODE sequences to microscopic anisotropy |
1CMIC, University College London, London, United Kingdom, 2Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal |
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In the long mixing time regime, double-diffusion-encoding (DDE) sequences provide contrast capable of reflecting microscopic anisotropy, which may have added value for highly heterogeneous tissues such as the gray matter. Recently, double-oscillating-diffusion-encoding (DODE) sequences, which combine oscillating waveforms and varying gradient orientation, have been proposed to improve sensitivity to microscopic anisotropy. This work investigates the effect of varying different sequence parameters and shows that DODE sequences provide higher sensitivity to pore size for elongated pores, while DDE sequences are more sensitive to pore eccentricity. |
| 3010
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Computer #5 |
A novel iterative approach to reap the benefits of multi-tissue CSD from just single-shell (+b=0) diffusion MRI data |
1The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 2The Florey Department of Neuroscience, University of Melbourne, Melbourne, Australia |
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Constrained spherical deconvolution (CSD) is a robust approach to resolve the fibre orientation distribution (FOD) from diffusion MRI data. However, the FOD from CSD only aims to represent "pure" white matter (WM) and is inappropriate/distorted in regions of (partial voluming with) grey matter (GM) or cerebrospinal fluid (CSF). Multi-shell multi-tissue CSD was proposed to solve this issue by estimating WM/GM/CSF components, but requires multi-shell data to do so. In this work, we provide the first proof that similar results can also be obtained from only simple single-shell (+b=0) data, and propose a novel specialised optimiser that achieves this goal. |
| 3011 | Computer #6 |
Double-Pulsed-Field Gradient MRI in the Long Evans shaker rats' spinal cords |
1School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel, 2Medical Sciences, The University of Wisconsin-Madison, Madison, WI, United States, 3Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel |
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Double pulsed-field gradient (d-PFG) MRI has recently been suggested as an additional methodology for studying microstructure in the CNS. The Long Evans shaker (les) rats’ CNS has been previously studied by q-space diffusion (QSI) and more recently by angular d-PFG MRI. Here, we characterize the microstructure of the les spinal cords by fitting the angular d-PFG MRI data to the multiple correlation function (MCF) and extracting the unique parameter L/R ratio and its fractions. Clearly, the angular d-PFG methodology is capable of distinguishing between the les and their controls, in white matter and even in some gray matter ROIs. |
| 3012 | Computer #7 |
Effects of the Number of Diffusion Directions in Diffusion Kurtosis Imaging: a Structural Connectivity Study using in vivo data |
1Instituto de Biofísica e Engenharia Biomédica, Lisbon, Portugal, 2Cognition and Brain Science Unit, MRC, Cambridge, United Kingdom, 3Centre for Neuropsychopharmacology, London, United Kingdom |
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Diffusion Kurtosis Imaging Tractography Reconstructions (DKI-TR) are often performed using high quality data. In clinical practice, that is often not possible, as only a lower number of b-values and diffusion gradient directions can be acquired. This study assessed the performance of DKI-TR for the two algorithms currently proposed for DKI-TR using variable amounts of data, and looked at their respective structural connectivity metrics. A 64 gradient direction data set was acquired in six healthy subjects, and down-sampled to 21 and 32 directions. Differences were found between gradient sets and also between algorithms, regarding the reconstructions and the connectivity metrics. |
| 3013 | Computer #8 |
Assessment of Diffusion Time Dependence of Diffusion Kurtosis in Rat Spinal Cord |
1Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 2Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 3Radiology and Radiological Sciences, Vanderbilt University School of Medicine, Nashville, TN, United States, 4Electrical Engineering, Vanderbilt University, Nashville, TN, United States |
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Diffusion kurtosis imaging (DKI) is an extension of DTI with the ability to provide additional information about tissue microstructure. To evaluate the diffusion time dependence of diffusion kurtosis, kurtosis is measured perpendicular to white matter tracts in rat spinal cord for diffusion times ranging from 12 to 100 ms. In this study, kurtosis increased as a function of diffusion time in white matter, yet decreased in gray matter. Assessing the change in diffusion kurtosis across diffusion time could potentially inform upon the underlying white matter microstructure. |
| 3014 | Computer #9 |
Time-dependent diffusion on in vivo human brain data from the Connectom scanner |
1Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Institute of Neurology, University College London, London, United Kingdom, 3Department of Computer Science, University College London, London, United Kingdom |
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Diffusion MRI models for brain microstructure do not currently incorporate time-dependent diffusivity. Previous studies with ex vivo tissue (muscle and brain) have observed such dependency. The advent of high diffusion gradient scanners have enabled us to probe the tissue to unprecedented. Here we examine and observe the time dependency of the measured diffusion using data from the live human brain.
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| 3015 | Computer #10 |
Between-Session Variability of Diffusion Kurtosis Metrics in in vivo Brains |
1Institute of Neuroscience and Medicine - 4, Forschungszentrum Jülich GmbH, Jülich, Germany, 2Department of Neurology, Faculty of Medicine, JARA, RWTH Aachen University, Aachen, Germany |
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The knowledge of intra- and inter-subject variability of diffusion kurtosis imaging metrics plays an important role in the interpretation of the results in clinical trials. However, it has not been sufficiently studied thus far. The purpose of this work is to investigate between-session variability of a single subject with N-repeated measurements with an identical experimental protocol, and thus to provide the baseline for comparison with phantom measurements and inter-subject in vivo variability. We quantified variability in terms of the coefficient of variation and studied how its value varies between various diffusion tensor and kurtosis metrics estimated in twenty anatomical regions. |
| 3016 | Computer #11 |
The importance of b-values selection and the precision of diffusion kurtosis estimation by the conventional schemes |
1CFIN, Aarhus University, Aarhus, Denmark, 2Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal, 3Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark |
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In DKI imaging studies, a wide range of different gradient strengths is used, which is known to affect the estimated kurtosis. Being driven by a need to assess the validity of the DKI expression and the accuracy of the estimated parameters as a function of b-value we both evaluated the variability of the kurtosis parameter for the in vivo and ex vivo data for different fitting techniques and studied the error in a mean kurtosis parameter with respect to the ground truth. The results and conclusions suggest circumspection while preferring a specific technique. |
| 3017 | Computer #12 |
Diffusion Kurtosis Breast Imaging model – Which should be the highest b-value? |
1Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal, 2Escola Superior de Tecnologia da Saúde fo Porto, ESTSP/IPP, Porto, Portugal, 3Hospital de São João, Porto, Porto, Portugal, 4Institute of Biomedical Engineering, University of Oxford, United Kingdom, Oxford, United Kingdom |
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For the application of the Diffusion Kurtosis Imaging (DKI) model, the use of higher b values is advised. Here, the diagnostic performance of the DKI model in the differentiation of benign and malignant breast tumors was studied for the first time regarding the most suitable higher b-value (2000, and 3000 s/mm2). In this study were included 36 benign and 75 malignant lesions, assessed using combinations of b-values 50 to 2000, and to 3000s/mm2. The b-value range 50 to 3000 s/mm2 showed the best results regarding diagnostic performance and so this range is suggested for use in future DKI breast cancer studies. |
| 3018 | Computer #13 |
A new framework for the optimisation of multi-shell diffusion weighting MRI settings using a parameterised Cramér-Rao lower-bound |
1INM 4 - Medical Imaging Physics, Forschungszentrum Jülich, Jülich, Germany, 2Experimental Physics III, TU Dortmund University, Dortmund, Germany, 3Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany, 4German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany |
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We propose a parameterisation for multi-shell diffusion gradient settings which is sufficiently flexible to cover a broad range of experimental configurations, on the one hand, but uses only 6 degrees of freedom, on the other. Thus, such parameterisation enables a robust optimisation of the diffusion weighting settings by minimising the Cramér-Rao lower bound of the parameters of interest. Finally, we demonstrate its performance in the context of the biexponential diffusion tensor analysis. |
| 3019
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Computer #14 |
A Robust Reconstruction Method for High Resolution Multishot DWI: SPIRiT-based SYMPHONY |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of |
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SYnergistic iMage reconstruction using PHase variatiOns and seNsitivitY (SYMPHONY) is a reconstruction method for multi-shot DWI which can provide high resolution diffusion weighted images. In this study, we proposed a SPIRiT-based SYMPHONY method in which a self-consistency constraint is applied instead of the conventional GRAPPA kernel to further improve the robustness of SYMPHONY. Simulation and in-vivo experiment validated the benefits of the proposed method which can improve the accuracy of reconstruction with less navigator data. |
| 3020 | Computer #15 |
Self-calibrated K-space Phase Correction Method for Multi-shot Diffusion Imaging |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of |
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Multi-shot EPI can achieve high resolution diffusion imaging, but the ghost artifacts caused by shot-to-shot phase variations must be corrected. In recent works, k-space phase correction methods have been proposed, which require navigator acquisitions for each excitation for calibrating the k-space interpolation parameters. In this work, a self-calibrated method for multi-shot DWI correction in k-space is proposed, which does not require navigator acquisitions for efficient scanning and does not suffer from the potential mismatch between image and navigator echoes. Experiments on liver DWI demonstrate that the proposed method can correct the motion induced artifacts in diffusion imaging. |
| 3021 | Computer #16 |
Diffusion Weighted 3D UTE Imaging Using Stimulated Echoes: Technical Considerations |
1Global MR Applications & Workflow, General Electric, San Diego, CA, United States, 2University of California San Diego, San Diego, CA, United States |
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Due to the fast decay rate of the transverse magnetization, diffusion weighting is challenging in short T2 tissues; only very limited b-values can be achieved before the signal decays to zero. In this work, we used stimulated echoes to allow spin diffusion while the magnetization is stored along the longitudinal axis, therefore achieving useful b-values and allowing examination of short T2 tissues. Several technical challenges have to be addressed however, such as minimizing the oscillatory signal banding due to the low diffusion gradient area and reducing T1 contamination in multi-spoke UTE acquisition. This initial proof-of-principle study shows good quantitative agreement with clinical EPI diffusion sequences. |
| 3022 | Computer #17 |
EPI-based diffusion-weighted MR imaging of the neck at 3 Tesla: Comparison of sequence technologies for the reduction of susceptibility-related artifacts. |
1University of Tuebingen, Tuebingen, Germany, 2Siemens Healthcare AG, Erlangen, Germany |
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The aim of this study was to compare different EPI-based MR sequence techniques (conventional EPI, zoomed EPI, readout-segmented EPI and integrated 2D shim EPI (iShim)) for diffusion weighted imaging of the neck at 3 Tesla. To this end, MR measurements of a dedicated phantom and in-vivo measurements in volunteers were performed. Our results suggest that iShim is the best option for DWI of the neck at 3 Tesla yielding good image quality and efficiently reducing spatial distortions and off-resonance artifacts. |
| 3023 | Computer #18 |
Optimization of b-value sampling using error propagation methods for intravoxel incoherent motion imaging for various organs |
1Research & Development Group, Hitachi, Ltd., Tokyo, Japan, 2Healthcare Company, Hitachi,Ltd., Chiba, Japan |
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In this study, we proposed a method for optimizing b-value sampling using error propagation methods for IVIM imaging. We investigated the difference in an optimal set of b-values depending on the organ and the effect of b-value sampling on the precision of IVIM parameters. The results show that the optimal b-values were divided into four b-values and the combination of b-values varied with the organ. The SNR increased 1.2–1.6 times by optimization. We concluded that the optimization of b-value sampling corresponding to an organ can improve the fitting precision of IVIM parameters. |
| 3024 | Computer #19 |
Multi-shot Cartesian TSE DWI with Inherent 2D Phase Correction |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of, 2Department of Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China, People's Republic of, 3Vascular Imaging Laboratory, Department of Radiology, University of Washington, Seattle, WA, United States |
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Single-shot EPI DWI suffers from geometric distortion which can mask the pathology. Single-shot TSE DWI can help settle the distortion problems, but the spatial resolution is limited. In this work, a multi-shot Cartesian TSE DWI method with improved in-plane resolution is proposed. The ghost artifacts from shot-to-shot phase variations are corrected using an image domain correction method. The results show that the proposed method provides diffusion images with improved resolution and insensitivity to susceptibility induced distortion artifacts. |
| 3025 | Computer #20 |
3D Ultrashort Echo Time Cones Sequence with Diffusion Weighted Imaging (3D UTE-Cones-DWI): Evaluation of the Angular Dependence of Diffusion in the Achilles Tendon |
1Department of Radiology, UCSD, San Diego, CA, United States, 2Global MR Application & Workflow, General Electric, San Diego, CA, United States |
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Diffusion weighted imaging (DWI) has been widely used to evaluate the rate of water diffusion in long T2 tissues such as the white matter of the brain. Tissues such as cortical bone, tendons, ligaments and menisci have short T2 and have little or no signal with conventional clinical MR sequences. Water diffusion in these tissues is inaccessible. Ultrashort echo time (UTE) sequences with TEs down to 8 µs have been employed to image the short T2 tissues. The combination of UTE and stimulated echo diffusion preparation (UTE-DWI) allows water diffusion to be evaluated in short T2 tissues. In this study we report the use of a novel stimulated echo (STE) diffusion prepared 3D UTE Cones sequence (3D UTE-Cones-DWI) for assessment of water diffusion in the Achilles tendon using a clinical 3T scanner. The magic angle dependence of apparent diffusion coefficients (ADC) determined through this sequence was also investigated. |
| 3026 | Computer #21 |
Quantitative evaluation of Apparent Diffusion Coefficient (ADC) from two DWI sequences – echo planar spin echo (EPSE) and read-out segmented echo planar (RESOLVE) imaging |
1Department of Radiology, St.Mary Hospital, Seoul, Korea, Republic of |
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The purpose of this study was to quantitatively evaluate ADCs from two different DWI sequences – echo planar spin echo (EPSE) and read-out segmented echo planar (RESOLVE) imaging. The mean ADCs of the whole brain, GM, WM and CSF were compared based on masking templates generated from T2-weighted images. Our results demonstrated that although difference between the two ADCs was statistically significant over the whole brain regions, ADCs from msDWI and ssDWI were highly correlated (R2 = 0.989). The relationship between the two ADCs should be considered to utilize it as an effective quantitative metric. |
| 3027 | Computer #22 |
The Optimization of Zoomed Field of View DWI (iZOOM) with Echo Planar Imaging (EPI) Sequence Excited by a Two Dimensional Radiofrequency Pulse (2D RF) on Prostate at 3.0 T |
1The Department of Radiology, Peking University First Hospital, Beijing, China, People's Republic of, 2Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China, People's Republic of, 3Philips Healthcare, Beijing, China, People's Republic of, 4Philips Healthcare (Suzhou) Co., Ltd, Suzhou, China, People's Republic of |
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This study aims to demonstrate the feasibility of iZOOM using a 2D RF pulse EPI sequence in the application of prostate DWI and the optimization of iZOOM at 3.0 T MRI. 58 patients took prostate MRI examination with 3 iZOOM sequences (1. b=1000, resolution: 1.4×1.4mm; 2. b=1000, resolution: 1.0×1.0mm; 3. b=2000, resolution: 1.4×1.4mm). Images were evaluated with the basic image quality, the display of lesions and overall image quality. The result shows iZOOM is feasible on prostate DWI. High b value and high resolution iZOOM are both favored by radiologists. |
| 3028 | Computer #23 |
Efficient Macroscopic Motion Correction for Multi-shot DTI |
1School of Biomedical Engineering and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China, People's Republic of, 2Philips Healthcare (Suzhou), Suzhou, China, People's Republic of, 3Philips Korea, Seoul, Korea, Republic of, 4Philips Healthcare, Guangzhou, China, People's Republic of |
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Though cMUSE proposed by our group tackles the pixels mismatch of macroscopic motion in multi-shot EPI by clustering and registration, it neglects altered gradient directions. In this work, we treat motion induced variations in gradient direction as addtional diffusion direction(s). The proposed method simply and effectively solves the gradient direction alternation due to macroscopic motion in multi-shot DTI. |
| 3029 | Computer #24 |
Acceleration motion compensation DWI for measuring intraventricular temperature |
1Depertment of Radiology, Tokai university hospital, Isehara, Japan, 2Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, Ishikawa, Japan, 3Depertment of Radiology, Tokai University School of Medicine, Isehara, Japan, 4Healthcare, Philips Electronics Japan Ltd., Tokyo, Japan |
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Although it has been reported a method for monitoring the intraventricular cerebrospinal fluid (CSF) temperature calculated from the DWI, this method was affected by the CSF pulsation. We proposed the acceleration-motion compensation DWI (aMC-DWI) to the determination of the intraventricular temperature to improve that accuracy and precision. Compared with conventional DWI, measurement of intraventricular temperature using aMC-DWI was accuracy even in ventricles with high flow, e.g., third ventricle, fourth ventricle. These results suggested that aMC-DWI is a suitable method for analyzing the intraventricular temperature. |
| Exhibition Hall | Monday, May 9, 2016: 16:30 - 17:30 |
| 3030 | Computer #25 |
Graph theoretical analysis of abnormal structural networks in obese patients using DTI tractography |
1Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, 2Department of Psychiatry, Chang Gung Memorial Hospital, Chiayi, Taiwan, 3Tiawan Center for Metabolic and Bariatric Surgery, Jen-Ai Hospital, Taichung, Taiwan, 4Department of Psychology, Chung Shan Medical University, Taichung, Taiwan, 5Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan |
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Obesity is one of the most serious public health concerns among adults and children in the 21st century, which increases risk of many other diseases, including cardiovascular risks, hypertension, dyslipidemia, endothelial dysfunction, etc., and it is commonly measured with body mass index (BMI). Previously studies about obesity mainly used diffusion tensor imaging (DTI) to examine the relationship between BMI and DTI parameters, and found that white matter integrity was reduced in obesity. However, the research about the particular structural brain network change of obese patients was tended to be less. Hence, our study aimed to map the structural connectomic changes over obese patients based on DTI tractography using graph theoretical and network-based statistic (NBS) analyses. In the result of graph theoretical analysis, poor ability of local segregation, global integration, and transitivity in the obese patients was found. In the result of NBS, decreased connections in structural connectivity network, and alterations in the corpus callosum region was observed. |
| 3031 | Computer #26 |
Automated rejection of motion-corrupted slices and optimised retrospective ghost correction for multi-shot DTI |
1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom, 2Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom |
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DTI sequences based on EPI allow rapid acquisitions of image slices by traversing k-space lines in opposite directions following a single RF excitation. During long acquisition trains, phase errors caused by field inhomogeneity can lead to distortion. Acquiring slices in multiple shots can mitigate this effect. Motion between shots, however, results in ghosting that cannot be corrected. We show that slice-wise phase correction by entropy minimisation reduces ghosting compared to the manufacturer software (ParaVision 4.0, Bruker). Second, we propose an algorithm to automatically detect and reject slices with residual motion-induced ghosting, and validate it in a large cohort of mice. |
| 3032 | Computer #27 |
Using A Hyperspherical Harmonic Basis for Sparse Multi-Voxel Modeling of Diffusion MRI |
1Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States, 2Medical Imaging Technologies, Siemens Healthcare, Princeton, NJ, United States, 3Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States |
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For diffusion magnetic resonance imaging (dMRI), 3D signals are acquired at each voxel to estimate neuronal fiber orientation in the brain. Traditionally, dMRI signals are reconstructed using the same basis for each voxel with added spatial regularization and sparsity constraints. By repeating the same basis for each voxel, there exist millions of redundant parameters to represent an entire brain volume. In this work, we reconstruct dMRI signals jointly across multiple voxels to reduce the number of parameters needed to represent a brain volume by 65%. Sparse dMRI representation is important for storage, information extraction, and reduction of clinical scan times. |
| 3033 | Computer #28 |
Caveats of probabilistic tractography for assessing fiber connectivity strength |
1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands |
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Despite previous reviews on the limitations of using probabilistic fiber tractography techniques for assessing the “strength” of brain connectivity, these tractography techniques are still being used for this purpose. The objective of this work is to characterize the reliability of probabilistic tractography for investigating connectivity “strength”. To this end, we demonstrate that the sensitivity of reconstructing fiber tracts with respect to the noise level and/or the choice of number of gradient directions is high, suggesting that the interpretation of such results for assessing the “strength” of connectivity should be used with extreme caution. |
| 3034 | Computer #29 |
Joint reconstruction of high-SNR multiple b-values diffusion-weighted images using projection onto convex sets based multiplexed sensitivity-encoding (POCSMUSE) |
1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong, 2Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC, United States |
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Intra-voxel incoherent motion (IVIM) MRI utilizes diffusion-weighted echo-planar imaging (DW-EPI) technique to acquire a set of image data with multiple b-values. The major limitation of IVIM is due to long acquisition time for multiple b-values that can lower the feasibility of clinical use, especially it requires multiple averaging of high-b value to compensate SNR loss. In this study, we propose a joint reconstruction framework of POCSMUSE algorithm, to simultaneously reconstruct under-sampled multi-b interleaved DW-EPI data with reduced noise amplification. |
| 3035 | Computer #30 |
Sparse re-parametrization of continuous Fibre Orientation Distributions using spherical harmonic delta functions |
1The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 2The University of Melbourne, Melbourne, Australia |
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Constrained Spherical Deconvolution (CSD) estimates the Fibre Orientation Distribution (FOD) in each voxel in the Spherical Harmonic (SH) basis. Although features of the underlying fibre configuration are captured within the FOD, the SH basis is not wholly appropriate for their analysis. We propose a re-parametrization of the FOD, fitting a sparse set of SH delta functions to each FOD, that additionally captures the anisotropic dispersion of each discrete fibre bundle. |
| 3036 | Computer #31 |
Reliable estimation of Diffusional kurtosis in the skeletal muscle needs perfusion correction. |
1Department of Information Engineering, University of Padova, Padova, Italy, 2Neuroimaging Lab, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini (LC), Italy, 3Department of Radiology, University Medical Center, Utrecht, Netherlands |
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Perfusion is known to affect the estimation of Diffusion Tensor Imaging (DTI) measures on the skeletal muscle. However, no previous works evaluated its effects on kurtosis estimation. Therefore, in this study we investigated the influence of perfusion on kurtosis. Synthetic signals for different perfusion levels with and without isotropic kurtosis were generated and then fitted with and without taking IVIM into consideration. Results showed that IVIM correction was essential to estimate non-biased values of kurtosis in case of increased perfusion. Real data showed that the simultaneous estimation of kurtosis and IVIM is robust and feasible. |
| 3037 | Computer #32 |
High field DTI and NODDI imaging to assess the effects of systemic inflammation on the pup rat brain. |
1Division of Child Growth & Development, Department of Pediatrics, University of Geneva, Geneva, Switzerland, 2Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3Department of Physiology, University of Auckland, Auckland, New Zealand |
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Infection-induced inflammation is a major cause of injury to the white matter and grey matter structures of the brain in the early preterm infant. In the present study, we assessed the long-term effects of early-life inflammation on white and grey matter microstructure using diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) at 9.4T. In this study, we characterized the microstructural consequences of LPS exposure in newborn pup rats recovered to P21. Mild changes in white matter and cortical development were observed without ventriculomegaly. DTI and NODDI can be used to assess subtle changes following LPS exposure. |
| 3038
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Computer #33 |
Unsupervised multi-tissue decomposition of single-shell diffusion-weighted imaging by generalization to multi-modal data |
1ESAT/PSI, Department of Electrical Engineering, KU Leuven, Leuven, Belgium, 2Medical Imaging Research Center, UZ Leuven, Leuven, Belgium, 3Translational MRI, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium, 4Medical IT Department, iMinds, Leuven, Belgium |
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Recent method developments have improved the reconstruction of fibre orientation distributions in white matter by incorporating partial voluming with isotropic grey matter and CSF. Yet, their use is limited to multi-shell data. Here, we present a generalization of convexity-constrained non-negative spherical factorization to multi-modal data, and illustrate its use for decomposing single-shell diffusion-weighted data and T1 anatomical data in three tissue components. Results show that we can effectively reconstruct fibre orientation distributions and separate isotropic volume fractions of grey matter and CSF in single-shell data, even at low b-values. |
| 3039 | Computer #34 |
A Trimodal non-Gaussian Diffusion Model for the Full Spectrum of Multi-b Diffusion MRI in Brain Tissue |
1Illinois Math and Science Academy, Aurora, IL, United States, 2Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, IL, United States, 3Radiology, University of Illinois Medical Center, Chicago, IL, United States, 4Bioengineering, University of Illinois at Chicago, Chicago, IL, United States |
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When examining brain diffusion weighted MRI (DW-MRI) images acquired at multiple diffusion weightings, i.e., b-values, it has become apparent that the DW-MRI measurements may not be completely explained with a Gaussian mono-exponential model. A trimodal model is proposed to fit the full spectrum of multi-b DW-MRI (from 0 to 5000 s/mm2) by incorporating a perfusion component, a stretch exponential component, and a 3rd distinct diffusion component. The trimodal model reduced the χ2 fitting residuals, provided an additional 3rd diffusion component with good white matter contrast without sacrificing contrast in the perfusion and stretch exponential components. |
| 3040 | Computer #35 |
Voxel Level Comparison of Two Anomalous Diffusion Models: Continuous-Time Random-Walk Model versus Fractional Motion Model |
1Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States, 2Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China, People's Republic of, 3Department of Radiology, University of Illinois at Chicago, Chicago, IL, United States, 4Departments of Radiology, Neurosurgery, and Bioengineering, University of Illinois at Chicago, Chicago, IL, United States |
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Over the past decades, several non-Gaussian diffusion models have been developed to reveal the underlying structures of the complex and heterogeneous tissue by measuring the anomalous diffusion behavior. Within these, continuous-time random-walk (CTRW) and fractional motion (FM) models have actively been studied by several groups to compare them at cellular or molecular level. In this study, we provide a comparison between the CTRW and FM models on human brain in vivo at the voxel level using high b-value diffusion MRI. It was observed that all CTRW and FM parameters exhibit characteristic contrasts, reflecting different aspects of the complex diffusion process. |
| 3041 | Computer #36 |
Novel Diffusion-Kurtosis-Informed Template to Reduce Partial Volume Effects in the Atlas-Based Analysis |
1Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich GmbH, Juelich, Germany, 2Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany |
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Between-group comparisons of diffusion tensor and diffusion kurtosis imaging metrics are important for elucidation of differences between pathology and healthy state. However, thus far, the methodology of such comparisons has not been well established. Frequently used methods, such as region-of-interest analysis or atlas-based analysis are subject to errors due to partial volume effects, whereas the track-based spatial statistics reduces consideration to a small amount of voxels along the skeleton, thus diminishing useful information. In this work we represent a simple, robust diffusion-kurtosis-informed template effectively reducing partial volume effects in the atlas-based analysis using less restrictive approach. |
| 3042 | Computer #37 |
Differentiating Contributions To Diffusional Kurtosis with Symmetrized Double-PFG MRI |
1Schlummerger-Doll Research, Boston, MA, United States, 2Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States |
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Kurtosis imaging enables valuable diagnostics of stroke and other tissue pathologies. It can arise both directly from restricted diffusion, and indirectly from averaging multiple microscopic environments. We develop an EPI imaging sequence utilizing double diffusion contrast that isolates the direct contribution. We demonstrate consistency with traditional kurtosis imaging in phantoms yet unique contrast in-vivo in a live rat brain. |
| 3043 | Computer #38 |
Whole-body diffusion weighted imaging in multiple myeloma: Temporal changes of Gaussian and non-Gaussian diffusion parameters following treatment. Initial experience at 3.0T |
1University College London, London, United Kingdom, 2University College London Hospital, London, United Kingdom |
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Diffusion weighted imaging's apparent diffusion coeffiecient (ADC) has been shown to be a potential imaging biomarker for monitoring treatment response in multiple myeloma. However, in most instances, a mono- exponential fitting model is used to assess temporal changes. In this work, we investigated the Gaussian and non-Gaussian fitting algorithms and their respective quantitative biomarkers for assessing response in multiple myeloma using whole body diffusion weighted imaging. |
| 3044 | Computer #39 |
Relative enhanced diffusivity in terms of intravoxel incoherent motion |
1Department of Radiology and Nuclear Medicine, St. Olav's University Hospital, Trondheim, Norway, 2Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway, 3St. Olav's University Hospital, Trondheim, Norway, 4Department of Physics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway |
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Relative enhanced diffusivity (RED) is a recently proposed parameter for DWI that is strongly weighted by pseudo-diffusion and provides good tissue discrimination using only three b-values. In this work we perform a theoretical study on the link between the RED parameter and the intravoxel incoherent motion (IVIM) model, and we derive a simple approximate expression for describing this relationship. |
| 3045 | Computer #40 |
Angular Complexity and Fractional Displacement Probability: New metrics for diffusion propagator imaging |
1Department of Neuroimaging, The Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom |
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Several methods have been used to represent the diffusion signal, and recently novel multi-shell approaches like SHORE, have allowed analytical and continuous reconstruction of the diffusion propagator. In this study, we propose two new metrics to better characterize the propagator at different displacement radii, the Angular Complexity Index (ACI), as a measure of propagator anisotropy, and the Fractional Displacement Probability (FDP), as index of relative mean displacement probability within fixed displacement bands. Furthermore, we display preliminary results that suggest sensitivity to microstructural organisation at different displacement scales, as opposed to traditional propagator metrics that reduce it to single scalar maps. |
| 3046 | Computer #41 |
Emerging applications of intravoxel incoherent motion MRI in primary nasopharyngeal carcinoma |
1Department of Radiology, Guangdong Academy of Medical Sciences/Guangdong General Hospital, Guangzhou, Guangdong Province, China, Guangzhou, China, People's Republic of, 2Russell H. Morgan Department of Radiology and Radiological Sciences, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore 21287, USA, Baltimore, AL, United States |
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Worldwide, nasopharyngeal carcinoma (NPC) is a rare malignancy, but it shows marked geographic and racial variation in incidence and is particularly endemic in southern China. The aim of our study is to compare pure molecular diffusion (D), perfusion-related diffusion (D*), perfusion fraction (f) and apparent diffusion coefficient (ADC) based on intravoxel incoherent motion (IVIM) theory in patients with NPC. Our results revealed that IVIM DWI is a feasible technique for investigating primary NPC. D was significantly decreased in primary NPC, and increased D* reflected increased blood vessel generation and parenchymal perfusion in primary NPC. |
| 3047 | Computer #42 |
Computed FLAIR-DWI Technique combined with DWI, PDW, T2W and T1W Imagings |
1MRI development department, Toshiba Medical Systems, Otawara, Japan, 2Clinical Application Research and Development Dept., Toshiba Medical Systems, Otawara, Japan |
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We proposed a new computed DWI technique allowing to provide quantitative maps of ADC, T2, T1 and DWI images with arbitrary contrast of PDW, T2W, and T1W. We clarified that our techniques enabled to provide FLAIR-DWI images with higher SNR than actually measured FLAIR-DWI, and furthermore enhanced by using SE-based ADC map and SE- or IR-based T1 map with optimal TI for brain tissue. Although further optimization is required, it is expected to be especially useful for clinical brain diagnosis. |
| 3048 | Computer #43 |
Correlation Time Diffusion Brain Mapping at 1.5T vs. 3.0T |
1Radiology, Boston University, Boston, MA, United States, 2Global MR Applications and Workflow, GE Healthcare, Boston, MA, United States, 3Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States |
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Purpose: To test the hypothesis that correlation time diffusion coefficient (DCT) MRI is not be dependent of the main magnetic field strength B0. Methods: A heathy volunteer was scanned (head) at 1.5T and 3.0T with the same diffusion mapping capable scans: quadra-FSE for DCT mapping and DW-SE-sshEPI for DPFG mapping. Results: Despite the B0 dependent shifts of the relaxation time (T1, T2) histograms, the DCT, DPFG, and PD histograms do not exhibited significant B0 shifts. Conclusion: The correlation time diffusion coefficient is theoretically and experimentally a genuine physical property inherent to biological tissue and independent of experimental variables including B0. |
| 3049 | Computer #44 |
Non-invasive characterization of BI-RADS 4/5 X-ray mammography findings using unenhanced breast MRI with fusion of diffusion weighted and morphological T2-weighted images |
1Department of Radiology, German Cancer Research Center, Heidelberg, Germany, 2Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany, 3Radiological Practice at the ATOS Clinic Heidelberg, Heidelberg, Germany, 4Radiology Center Mannheim (RZM), Mannheim, Germany |
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Additive unenhanced breast MRI prior to biopsy might reduce false positive x-ray mammograms. Therefore we evaluated the adjunctive diagnostic value of unenhanced breast MRI with image fusion of DWI and T2-weighted images and compared it to a side-by-side analysis of the sequences. 30 patients were included undergoing a 1.5 T breast MRI examination prior biopsy. We found that reading DWI/T2w-fused images alone decreased the accuracy (81.6% ±2.8%) compared to the side-by-side analysis (91.6% ± 2.3%) and significantly reduced the reader confidence significantly (p<0.001). Therefore fused image series should currently be considered always in addition to morphologic images since they could miss important morphologic information. |
| 3050 | Computer #45 |
Inherent correction of both geometric distortion and motion-induced aliasing artifacts in multi-shot diffusion-weighted EPI |
1Brain Imaging and Analysis Center, Duke University, Durham, NC, United States, 2Global MR Applications and Workflow, GE Healthcare, Boston, MA, United States, 3Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong |
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A new reconstruction framework is developed to simultaneously correct geometric distortion and motion-induced aliasing artifacts in multi-shot DW-EPI data without relying on additional calibration scan or field mapping. Through reversing the polarity of phase-encoding gradient between interleaves in multi-shot EPI, the field inhomogeneities and segment-specific phase information can be inherently estimated from DW-EPI data. High-quality DWI images free from distortions and aliasing artifacts can then be reconstructed with our new POCSMUSE method that uses coil sensitivity profiles, shot-to-shot phase variations, and field inhomogeneities as the input. |
| 3051 | Computer #46 |
The effect of subject motion on fractional anisotropy estimates: A simulation study of angular bias |
1Image Sciences Institute, UMC Utrecht, Utrecht, Netherlands |
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Subject motion during diffusion weighted MRI acquisition is a well-known confounding factor which can affect diffusion tensor metrics. In this simulation study, we investigated whether this confound is related to the change in distribution of diffusion gradient orientations due to the required “B-matrix rotation” during subject motion. According to our findings, subject motion can indeed generate a significant angular bias in addition to the noise bias, suggesting that subject motion itself may cause group differences in diffusion metrics. |
| 3052 | Computer #47 |
High-Resolution DWI using reduced FOV multi-shot EPI with IRIS reconstruction |
1Philips Healthcare (Suzhou), Suzhou, China, Suzhou, China, People's Republic of, 2Philips Healthcare Korea, Seoul, Republic of Korea, Seoul, Korea, Republic of |
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Multi-shot EPI using IRIS technique works fantastically in reduced FOV, which can enhance high resolution diffusion images. It can be a potential application for the research and clinical diagnosis in diffusion imaging. |
| 3053 | Computer #48 |
Highly accelerated graph theory implementations show benefits of finer cortical parcellations for group connectomic analyses |
1CUBRIC, School of Psychology, Cardiff University, Cardiff, United Kingdom, 2Neuroscience and Mental Health Research Institute (NMHRI), School of Medicine, Cardiff University, Cardiff, United Kingdom |
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Graph theoretical connectome analysis1 is an increasingly important research area. There is, however, high computational overhead required to: (a) produce whole or partial brain tractographies; (b) convert tractographies into binary or weighted graphs; and (c) analyse those graphs according to multiple, often complex graph metrics. We have developed GP-GPU accelerated implementations of each step. Exploiting the resultant increase in computational power, we examined the effects of increasing streamline sampling densities and number of cortical parcellations on separability of connectomes between first episode psychosis patients and controls. We show finer cortical parcellation increases separability (while increasing streamline density reduces it). |
| Exhibition Hall | Monday, May 9, 2016: 16:30 - 17:30 |
| 3054 | Computer #49 |
Novel diffusion markers for tract-based spatial statistics and bundle-specific analysis – feasibility study in patients with schizophrenia |
1Institute for Biomedical Engineering, ETH and University of Zurich, Zurich, Switzerland, 2Department of Psychiatry, Psychotherapy and Psychosomatics Psychiatric Hospital, University of Zurich, Zurich, Switzerland, 3Laboratory for Social and Neural Systems Research, Department of Economics, University of Zurich, Zurich, Switzerland |
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In the last few years, tract base spatial statistics (TBSS) become prominent tools for analyzing diffusion data in group studies. In this study, we introduce optimized high-resolution tract density (optTD) images based on tractograms. In order to avoid tractography bias, the tractograms are optimized using the convex-optimization modeling for microstructure informed tractography (COMMIT). The optTD were analyzed in a group of patients with schizophrenia and healthy controls using TBSS. Additionally, we have shown significant group differences comparing fiber weights derived from the COMMIT optimization. The introduced measures provide promising tools for investigating white-matter abnormalities in mental disorders. |
| 3055 | Computer #50 |
Mapping fibre dispersion and tract specific metrics in multiple fibre orientation using multi Bingham distributions |
1Cognition and Brain Sciences Unit, MRC, Cambridge, United Kingdom, 2Netbrainlab, Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom |
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In this study, a new approach to obtain improved fiber dispersion estimates by simultaneously fitting multi-Bingham distributions to the fODF is presented. |
| 3056 | Computer #51 |
Color this! An automatic algorithm to assign visually distinct colors to white matter bundles |
1Sherbrooke Connectivity Imaging Lab (SCIL), Université de Sherbrooke, Sherbrooke, QC, Canada |
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We propose a new technique to automatically assign visually distinct colors to streamlines bundles. Our technique takes into account spatial positioning of bundles to avoid assigning similar colors to neighboring bundles. This will help researchers visually disambiguate close bundles. We show that basic techniques simply trying to spread the colors through the available spectrum often fail to take neighbors into consideration, and assign visually indistinguishable colors to close bundles. Our technique is fully automatic and stable, giving the same color assignments for any subject with the same bundles and similar structure. |
| 3057 | Computer #52 |
Evaluation of tractography using Fiberfox for whole brain connectome analysis |
1Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States, 2Department of Physics, Indiana University, Bloomington, IN, United States |
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Due to the complexity of brain microstructure and organization, the validation of tractography results remains a challenging problem. In this work, effect of SNR and b value of diffusion imaging on the variability and errors of tractography was evaluated through a software phantom developed by Tractometer. Three fiber tracking algorithms based on DTI, CSD, and Q-sampling were tested. Large false positive and false negative rate was seen for all methods, regardless of SNR or b value. A moderate thresholding can reduce false positive rate and total error rate. |
| 3058 | Computer #53 |
Comparison of Automated and Hand-Drawn Tractography of the Optic Radiations in Children with NF1-Associated Optic Pathway Gliomas |
1Pediatrics, University Hospitals, Cleveland, OH, United States, 2Case Western Reserve University, Cleveland, OH, United States, 3Boston, MA, United States, 4Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, United States, 5Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States |
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Previous studies demonstrate that hand-drawn tractography of the optic radiations correlates with visual acuity in children with optic pathway glioma (OPG). However, automated tractography using a structural atlas would require less time and user expertise. We evaluated 50 children with OPG using both tractography methods. Both methods demonstrate significant differences in MD and RD between children with and without visual acuity loss. On multivariable analysis, both methods demonstrate a similar association between DTI measures and visual acuity. Automated tractography is a valid method to assess the optic radiations in children with OPG that requires less time and expertise. |
| 3059 | Computer #54 |
Improvement of probabilistic tractography of the corticospinal tract in human brain |
1Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy, 2Istituto Italiano di Tecnologia, Rovereto, Italy, 3Center for Neurosciences and Cognitive Systems, University of Trento, Rovereto, Italy |
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We performed an along tract analysis of the cortico-spinal tract in a group of healthy subjects using a probabilistic tractography algorithm. We were able to evaluate CST reconstruction along the tract using appropriate performance metrics, based on the congruence of fibre paths in the subject population, and the presence or absence of fibre tracks identified as originating from the precentral gyrus. The method was compatible with clinical protocols given spatial definition and tract localization obtained. |
| 3060 | Computer #55 |
Diffusion Tensor Imaging (DTI) of the myopathic and dystrophic skeletal muscle |
1Diagnostic and Interventional Radiology, University Medical Center Hamburg Eppendorf (UKE), Hamburg, Germany, 2Radiology, University of Texas Soutwestern Medical Center, Dallas, TX, United States, 3Neurology, University Medical Center Hamburg Eppendorf (UKE), Hamburg, Germany, 4MRI, Philips GmbH, Hamburg, Germany |
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MRI-Diffusion tensor imaging (DTI) based fiber tracking is an emerging tool for the evaluation of alterations in the skeletal muscle architecture caused by trauma and various inflammatory or hereditary diseases. It remains still a matter of debate, whether dystrophic conditions of the skeletal muscle, which are frequently associated with fatty infiltration, can be reliable assessed by DTI, as previous studies showed the potential biasing effect of the fat fraction (%FF) and the concomitant decrease of the signal to noise ratio (SNR) [1, 2]. The goal of this study was to analyze the DTI based apparent diffusion coefficient (ADC), fractional anisotropy (FA) and tractography data in various conditions of muscular disease, either with or without increase of the FF in comparison to healthy controls on a 3T system. |
| 3061 | Computer #56 |
A novel diffusion tensor imaging phantom that simulates complex neuro-architecture for potential validation of DTI Processing |
1Synaptive Medical, Toronto, ON, Canada |
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In this work a DTI phantom containing complex geometries and anisotropic microstructure to mimic fiber bundles is presented. The phantom consists of ten individual fiber bundles distributed in different orientations to best test and confirm proper DTI processing. Each fiber bundle contains 4.4 million fibers within a flexible casing. The phantom was imaged using a 2D EPI DTI sequence, and tractography was generated using BrightMatter™ Plan. Agreement was found between fiber location and tractography: FA values averaging 0.51, were within +/- 10% of the overall FA average within the fibers demonstrating consistent diffusion throughout the fiber bundles. |
| 3062 | Computer #57 |
Uncover of fiber reorientation in the medial human cortex in vivo |
1Department of Biomedical Magnetic Resonance, Institute of Experimental Physics, Magdeburg, Germany |
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Higher spatial resolution at ultra-high field (≥7T) magnetic resonance imaging (UHF MRI), with consequent reduction of partial volume effects, enables diffusion tensor imaging (DTI) to visualize sharp turns of the white matter (WM) fibers into grey matter cortex (CTX), which are challenging to see in the lower main magnetic field data. More, UHF DTI data also recover rather high fractional anisotropy (FA) in several CTX regions, which may help to minimize the strong gyral bias in tractography that are found even in the relatively high resolution 3T DTI. In this work we analyse statistical properties of DTI major eigenvectors at UHF as in WM-CTX interface as in medial CTX to understand fiber orientation characteristics in the whole human brain in vivo and allow connectivity analysis from white matter into the cortex. |
| 3063 | Computer #58 |
Construction of a diffusion MRI brain template using Human Connectome Project database |
1Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan |
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The present study uses the diffusion data of the human connectome project (HCP) as well as a state-of-the-art registration strategy to develop a diffusion template in the ICBM-152 space. A total of 489 diffusion datasets were included in the template construction. The HCP diffusion template matches to the ICBM-152 space well, in both the deep and superficial white matter regions. In addition, this template is capable of revealing detailed diffusion-dependent structures, such as the cortical-depth dependence of general fractional anisotropy (GFA). The HCP diffusion template is potentially useful in segmenting fine fiber tracts and parceling thalamic nuclei or hippocampal subfields. |
| 3064 | Computer #59 |
Examining Global White Matter Development via the Sparse Coding Properties of Diffusion-Weighted MRI |
1University of California, Los Angeles, Los Angeles, CA, United States, 2University of Southern California, Los Angeles, CA, United States |
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To avoid the assumptions inherent in diffusion modeling and tractography, we develop a new approach for studying global white matter development that operates on diffusion-weighted MR images directly. We apply a sparse coding method, K-SVD, to decompose a diffusion-weighted series. We quantify the efficiency of the resulting encoding by computing the Gini coefficient. We then show that this measure increases in a predictable manner throughout normal pediatric development. Our results support the hypotheses that more organized white matter can be more sparsely encoded and that the sparsity of the encoding may thus be used to infer the state of development. |
| 3065 | Computer #60 |
DTI with embedded PLACE: geometric distortion correction with no extra scan time and reduced motion sensitivity |
1Centre for Addiction and Mental Health, Toronto, ON, Canada, 2Department of Radiology, University of British Columbia, Vancouver, BC, Canada, 3Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 4Department of Psychiatry, University of Toronto, Toronto, ON, Canada |
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A phase-based method, PLACE, is embedded into a stock DTI sequence to enable geometric distortion correction without the need for extra scans. We show that geometric distortion correction via this embedded PLACE DTI sequence performs like the more traditional B0-map based correction schemes when there is no motion between scans. Furthermore, when motion occurs, embedded PLACE yields superior results. This embedded PLACE DTI is thus more efficient and less sensitive to motion than traditional B0 mapping methods. |
| 3066 | Computer #61 |
A comparison of multiple acquisition strategies to overcome B1 inhomogeneities in diffusion imaging of post-mortem human brain at 7T |
1FMRIB Centre, University of Oxford, Oxford, United Kingdom, 2Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom |
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In this work we compare a single flip angle and dual flip angle approach to overcome B1 inhomogeneities in DW-SSFP data of post mortem human brain at 7T. Both approaches were designed and optimized to achieve optimal CNR with whole brain coverage. The single flip angle approach displayed slight improvements in orientation estimates; however, the dual flip angle approach is being further investigated as a potential source of microstructural estimates with little to no cost in orientation. |
| 3067 | Computer #62 |
Deformation Based Morphometry using Diffusion Tensor MRI (DTI) Data |
1Section on Quantitative Imaging and Tissue Sciences, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States, 2Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 3Henry Jackson Foundation, Bethesda, MD, United States, 4Functional Rehabilitation Unit - Neuromuscular Disorders, IRCCS E.Medea Institute, Bosisio Parini, Italy, 5Neuroimaging Lab, IRCCS E.Medea Institute, Bosisio Parini, Italy |
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Tensor based morphometry (TBM) is a class of deformation based morphometry (DBM) methods that is traditionally performed on T1-weighted images (T1W). Here, we investigate the sensitivity of TBM by comparing the results of TBM, based on T1W and diffusion tensor imaging (DTI) data in patients diagnosed with SPG11, a neurological condition with a known genetic basis. TBM based on T1W and diffusion data captured the volumetric changes along the corpus callosum,which is a known characteristic of SPG11 patients, but does not fully explain the disorder. In contrast, only DTI-TBM identified volumetric changes in several association and projection pathways suggesting greater sensitivity of DTI-TBM. |
| 3068 | Computer #63 |
Motion correction for abdominal diffusion weighted images by using fitting accuracy guided free-form deformation. |
1School of Biomedical Engineering and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, GuangZhou, China, People's Republic of, 2Philips Healthcare, GuangZhou, China, People's Republic of, 3Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, GuangZhou, China, People's Republic of, 4Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 5Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, People's Republic of |
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Free-form deformation registration has been widely used but would lead to unwanted bias in the registration of different b-value images to b0 image, especially high-b-value images, due to signal attenuation dependent on b values. We use fitting accuracy to guid free-form deformation registration. The results of our proposed method can well realign the different b-value images in liver edges and improve the fitting accuracy. |
| 3069 | Computer #64 |
A New Method to Construct and Validate an Optic Radiation Template using Probabilistic Tractography |
1Sydney Neuroimaging Analysis Centre, Camperdown, Sydney, Australia, 2Brain and Mind Centre, University of Sydney, Camperdown, Sydney, Australia, 3Ophthalmology, Save Sight Institute, University of Sydney, Sydney, Australia, 4Australian School of Advanced Medicine, Macquarie University, Sydney, Australia |
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In-vivo delineation the white matter (WM) fibre bundles with diffusion-weighted imaging (DWI) and tractography facilitates the study of tract-specific damage due to neurological disease. However, this approach is limited by suboptimal or absent DWI datasets. Accurate atlas based white matter segmentation may provide an alternative method that can be broadly applied to existing neuroimaging datasets . Using the optic radiation as an example, we propose a new framework for the mapping and validation of white matter tracts in healthy subjects using probabilistic tractography. |
| 3070 | Computer #65 |
Recovery of Lost Connectivities in the Human Brain Connectome as Enabled by Ultra High Spatial Resolution Diffusion MRI |
1Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC, United States |
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Typical diffusion tensor imaging datasets are acquired at relatively low spatial resolutions (~2 mm) because of limitations in commonly used single-shot echo-planar imaging (EPI) protocols. However, within a relatively coarse voxel, it is often difficult for fiber tracking algorithms to accurately resolve short association fibers (e.g. cortical u-fibers) with very high curvature. As these fibers play an important role in linking adjacent gyri and constructing the human connectome, this report aims to quantify the recovery of lost connections and the improved accuracy of mutual connectivities between ROIs through high spatial resolution (enabled by multi-shot EPI based on multiplexed sensitivity encoding). |
| 3071 | Computer #66 |
Assessment of Rotationally-Invariant Clustering Using Streamlet Tractography |
1Department of Computer Science, University of Copenhagen, Copenhagen, Denmark, 2DTU Compute, Technical University of Denmark, Lyngby, Denmark |
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We present a novel visualisation-based strategy for the assessment of a recently proposed clustering technique for raw DWI volumes which derives rotationally-invariant metrics to classify voxels. The validity of the division of all brain tissue voxels into such classes was assessed using the recently developed streamlets visualisation technique, which aims to represent brain fibres by collections of many short streamlines. Under the assumption that streamlines seeded in a cluster should stay within it, we were able to assess how well perceptual tracing could occur across the boundaries of the clusters. |
| 3072 | Computer #67 |
Comparing the performances of three diffusion kurtosis tensor estimation algorithms via a ground truth diffusion template derived from HCP data |
1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 2Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States |
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A diffusion weighted imaging template is proposed, which is derived from the in vivo data from the HCP database. Diffusion weighted signals are generated from this template using the DKI tensor model, and diffusion tensor and kurtosis tensor metric maps are produced. These maps established the ground truth, against which the outputs of different DKI tensor estimation algorithms were compared. Rician noise is added to simulate typical diffusion MRI acquisitions with different SNR levels. The performances of the algorithms are then compared via voxel-wise Mean Square Error and bias-plus-variance decomposition to determine the optimal algorithm for the desired application. |
| 3073 | Computer #68 |
Automatic DWI denoising using TGV with local dependent noise estimate |
1Neuroradiology, Medical University of Graz, Graz, Austria, 2Mathematics and Scientific Computing, University of Graz, Graz, Austria, 3Psychology, University of Graz, Graz, Austria, 4Neurology, Medical University of Graz, Graz, Austria |
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High-resolution diffusion weighted imaging (DWI) with reduced susceptibility artifacts can be acquired using readout-segmented echo planar imaging (rs-EPI). The poor SNR that limits the applicability of this technique increases the need for denoising strategies. We introduce a novel user independent algorithm for denoising DWI data utilizing total generalized variation (TGV)regularization under consideration of the spatial dependent noise distribution. The feasibility of the proposed method was tested on synthetic DWI data at different noise levels and compared with non-local-means (NLM) filtering. |
| 3074 | Computer #69 |
Cortico-Subcortical motor network integrity relates to functional recovery after stroke |
1Computer Science, University of Verona, Verona, Italy, 2Institute of Nuclear Medicine, UCL, United Kingdom, 3Neuroradiology, University Hospital Verona, Italy, 4École polytechnique fédérale de Lausanne, Switzerland, 5Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Chalestown, MA, United States, 6Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG, Lausanne, Switzerland |
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In this work, we investigated whether the structural properties of cortico-subcortical (CS) motor circuits are related to motor outcome after stroke. To do this, we acquired Diffusion Spectrum Imaging data in 10 stroke patients at 3 time points after stroke. We then performed tractographic reconstruction and estimated a number of microstructural indices, derived from the 3D Simple Harmonic Oscillator based Reconstruction and Estimation (SHORE) model, in the cortico-subcortical motor fiber tracts. Linear regression analysis showed that that SHORE metrics of thalamo-cortical and intrastriatal connections in the first week after stroke are strongly related to stroke recovery at 6 months follow-up. |
| 3075 | Computer #70 |
Comparisons of cortical depth dependence of diffusion properties over the whole human brain in-vivo |
1Department of Biomedical Magnetic Resonance, Institute of Experimental Physics, Magdeburg, Germany |
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Ultra-high field (≥7 T) magnetic resonance imaging possesses substantial sensitivity to depict patterns of tissue cytoarchitecture. Recent studies have shown a cortex depth dependence of diffusion tensor invariants such as fractional anisotropy and mean diffusivity. In this study we further probe the potential of diffusion tensor imaging for the whole human brain in vivo by mapping it on the segments of Desikan-Killiany atlas. Such analysis complied via very precise distortion correction procedure and building a series of lamellae, allows one to understand a spatial specificity of marginal distribution of diffusion tensor invariants and reveal unusual effects in fiber topology. |
| 3076 | Computer #71 |
Asymmetrical cerebral response to appetite in mice |
1Instituto de Investigaciones Biomédicas "Alberto Sols", Madrid, Spain, 2Universidad Autónoma de Madrid, Madrid, Spain, 3École Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland |
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We investigate the global cerebral response to appetite in mice by functional Diffusion Weighted Imaging, implementing two independent, but complementary, methods of data analysis; a) Model-free classification algorithm and b) Biexponential diffusion parameter fittings. The model-free approach allowed the pixel by pixel calculation of appetite index maps, used to classify the brain between fed and fasted conditions. Biexponential model fittings allowed the calculation of diffusion parameter maps, revealing significant increases in diffusion parameters through the whole fasted brain. Both methods detected an asymmetric cerebral response to appetite with the right cerebral hemisphere becoming more responsive. |
| 3077 | Computer #72 |
3D Curvature of Medial Gastrocnemius (MG) Muscle Fibers Tracked from Diffusion Tensor Images (DTI): Age Related Differences in 3D fiber curvature. |
1Physics, San Diego State University, San Diego, CA, United States, 2Physics, University of California at San Diego, San Diego, CA, United States, 3Radiology, University of California at San Diego, San Diego, CA, United States |
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Muscle fiber curvature influences muscle function but 3D curvature of the MG remains unexplored. This study determines 3D fiber curvature from young and old cohorts from MG fibers tracked using DTI data. The fiber coordinates are fit to a 2nd or 3rd order polynomial before extracting curvature using the Frenet–Serret relationship. The order of the polynomial affects curvature values and the choice may depend on muscle fiber shape. Regional curvature changes were significant between distal and central in the deep, middle and superficial compartments. No significant changes were seen in the curvature between young and old subjects |
| Exhibition Hall | Monday, May 9, 2016: 16:30 - 17:30 |
| 3078 | Computer #73 |
Longitudinal Comparison of Diffusion Imaging Modeling in Rat Spinal Cord Injury |
1Biophysics Graduate Program, Medical College of Wisconsin, Milwaukee, WI, United States, 2Medical Scientist Training Program, Medical College of Wisconsin, Milwaukee, WI, United States, 3Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States, 4Neuroscience Doctoral Program, Medical College of Wisconsin, Milwaukee, WI, United States, 5Clement J. Zablocki Veteran's Affairs Medical Center, Milwaukee, WI, United States, 6Department of Biomedical Engineering, Marquette University, Milwaukee, WI, United States |
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A rat model of graded spinal cord injury was used to evaluate several diffusion models for the ability to detect injury at acute and chronic time points. Parameters from diffusion tensor imaging, free water estimation, diffusion kurtosis imaging, and white matter tract integrity models demonstrated that higher order modeling showed better separation of injury severity, especially in the chronic time point. Furthermore, parameters sensitive to volume changes associated with edema and inflammation demonstrated the greatest separation of these injury groups, indicating the importance of these processes in altering diffusion characteristics in spinal cord injury. |
| 3079 | Computer #74 |
Intracellular metabolites exhibit non-Gaussian diffusion in the healthy human brain using magnetic resonance spectroscopy at 7 Tesla |
1C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands |
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Since choline mostly resides in astrocytes, N-acetyl-aspartate mostly presides in axons, and creatine is distributed between both neural cell types, these intracellular metabolites can provide more specific microstructural compartment information compared to water. In this study, we apply diffusion-weighted spectroscopy to analyze axonal and glial structures by identifying non-Gaussian movement of intracellular metabolites in both white and gray matter of the healthy human brain at b-values up to ~17,000 s/mm2. We establish that all measured metabolites exhibited non-Gaussian subdiffusion in both tissue types with the gray matter intracellular space appearing more heterogeneous than white matter, opposite to water diffusion dynamics. |
| 3080 | Computer #75 |
Relations between the stretched exponential DWI model and tumor malignancy related microstructural changes |
1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas city, KS, United States, 2Department of Biology, University of Hawaii, Manoa, HI, United States, 3Neuroimaging research, Barrow Neurological Institute, Phoenix, AZ, United States, 4Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States, 5Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, United States |
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Diffusion weighting imaging (DWI) has been shown to be useful in differentiating low- and high-grade tumors in the brain. The decreased apparent diffusion coefficient (ADC) has been associated with increased tumor cellularity. However, tumor malignancy involves multiple microstructural changes that may also affect changes in the ADC. The alternative way to assess water diffusion in the complex microstructure is through the diffusion heterogeneity measured by the stretched exponential model (α-DWI). Recent studies using the α-DWI model have shown the increased diffusion heterogeneity in high-grade tumors. However, it remains unclear about the microstructural information provided by the α. The purpose of this study was to investigate how the α-DWI model responds to tumor malignancy related microstructural changes. We simulated a 3-D microenvironment in tumors and a DWI experiment. We studied how ADC and the fitted parameters of the α-DWI model responded to microstructural changes related to tumor malignancy. |
| 3081 | Computer #76 |
Validation and comparison of diffusion MR methods measuring transcytolemmal water exchange rate |
1Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, 2Radiology, The Second Hospital of Hebei Medical University, Shijiazhuang, China, People's Republic of |
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Two diffusion-based method, the CG (constant gradient) and FEXI (filtered exchange imaging) methods, have been developed to provide a flexible and safer means to measure transcytolemmal water exchange rate $$$k_{in}$$$ non-invasively in vivo. However, neither methods have been fully validated up to date. In the present work, computer simulations and in vitro experiments with well-controlled cultured cells with different sizes and permeabilities were performed to evaluate the accuracy of the CG and FEXI methods. The results suggest that $$$k_{in}$$$ can be accurately estimated when $$$k_{in}$$$ < 10 Hz. Although the FEXI method provides less accurate results, the linear dependence of AXR on $$$k_{in}$$$ suggesting it is still a reliable method. |
| 3082 | Computer #77 |
Metrics of microscopic anisotropy: a comparison study |
1CMIC, University College London, London, United Kingdom, 2Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal |
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Microscopic anisotropy disentangles the effects of pore shape from orientation distribution, and thus can serve as a valuable metric for underlying microstructural configurations. Recent developments in diffusion MRI proposed different approaches to acquire and analyse data for extracting information regarding microscopic anisotropy. This work compares in simulation two recently introduced metrics of microscopic anisotropy: fractional eccentricity (FE), derived from double-diffusion-encoding (DDE) sequences and microscopic fractional anisotropy (μFA), derived from a combination of sequences with isotropic and directional diffusion weighting. We find that DDE-derived metrics are more reliable for quantifying underlying microstructures if diffusion is restricted, while μFA is closer to the ground truth values when individual micro-domains feature Gaussian diffusion. |
| 3083 | Computer #78 |
Apparent Exchange Rate in Multi-compartment Anisotropic Tissue |
1CR Development, AB, Lund, Sweden, 2CFIN/MINDLab, Department of Clinical Medicine, Aarhus University, Arhus, Denmark, 3Department of Physics and Astronomy, Aarhus University, Arhus, Denmark, 4Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Copenhagen, Denmark, 5Lund University Bioimaging Center, Lund University, Lund, Sweden, 6Physical Chemistry, Lund University, Lund, Sweden |
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Filter exchange imaging (FEXI) is a noninvasive method to probe Apparent Exchange Rate (AXR). Understanding how diffusion anisotropy affects AXR is fundamental in experimental design and interpretation of results. In case of only two compartments, AXR is isotropic regardless of diffusion anisotropy. The key finding of this work is that AXR is anisotropic even in systems with a single exchange rate if there are more than two orientationally dispersed compartments. These findings may guide identification of different fiber populations and their directions and could be useful for analysis of fiber-specific characteristics. |
| 3084 | Computer #79 |
Simulating axon packing for investigating white matter tissue characteristics with diffusion MRI |
1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands, 2Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States |
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A novel algorithm for simulating axon packing in nerve bundles is proposed. Statistical analysis of the results demonstrates that, in contrast to conventional methods, the proposed method eliminates the bias in the estimated distribution and achieves higher packing densities, while preserving the random nature of the axon packing structure. The resultant tissue models can be used subsequently to study the Brownian motion of water molecules within nerve bundles. With our novel axon packing simulation framework, the effect of axon properties on the derived diffusion-weighted MR signal can be investigated more reliably now. |
| 3085 | Computer #80 |
Magnetic Resonance Diffusion Pore Imaging on Preclinical 9.4T-Animal-Scanner |
1Computer Assisted Clinical Medicine, Heidelberg University, Medical Faculty Mannheim, Mannheim, Germany, 2Department of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany |
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The study of porous microstructures is of high interest in medical imaging. Diffusion pore imaging (DPI) has recently been proposed as a means to acquire images of the average cell shape in a voxel or region of interest. In this work, we present the feasibility of DPI phantom measurements on a preclinical 9.4T animal scanner for the first time and preliminarily compare two different sequence implementations. The shown feasibility on a preclinical system opens the possibility of a potential in-vivo measurement realization. |
| 3086 | Computer #81 |
Diffusion microstructure in the population: variability and effect size of biophysical compartment model parameters over 100 subjects |
1Maastricht University, Maastricht, Netherlands |
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Statistical power in neuroscience studies is often limited, leading to, among others, low reproducibility of results[1]. Robust effect size estimates over a large subject group are crucial for power assessments. Here, we computed these estimates for microstructural differences in splenium, body and genu of the Corpus Callosum (CC) using diffusion MRI microstructure modeling over 100 subjects. We fitted Tensor, Ball&Stick, NODDI and CHARMED using GPU-accelerated software (MDT) and extracted subject specific parameters for the CC for each model. We observe medium to large effect sizes (Cohen’s d=1-3) for dMRI microstructure measures, promising for power and reproducibility of dMRI microstructure studies. |
| 3087 | Computer #82 |
Obtaining geometrical information from the time-dependent apparent diffusion coefficient |
1CMAP, INRIA, Ecole Polytechnique, Palaiseau Cedex, France |
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Diffusion MRI (dMRI) has been established as a useful tool to obtain voxel-level information on the tissue micro-structure. An important quantity measured in dMRI is the apparent diffusion coefficient (ADC), and it has been well established by in-vivo brain imaging experiments that the ADC depends significantly on the diffusion time. We derive an explicit formula for the time-dependent ADC, and, using the ADCs at multiple diffusion times and gradient directions, we estimate the surface to volume ratio, the eigenvalues and the first moment of the dominant eigen-functions associated to the geometry of the biological cells. |
| 3088 | Computer #83 |
Precise Inference of Cellular and Axonal Structural Organization (PICASO) using diffusion MRI |
1Brigham and Women's Hospital, Boston, MA, United States, 2Harvard Medical School, Boston, MA, United States |
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We propose a novel model termed PICASO for investigating the microstructural layout of brain tissue using in vivo diffusion MRI (dMRI) measurements. Our method provides a direct connection between the structural organization of biological tissue and a function representing the disorder in the evolution of magnetization density. This is achieved by extending the Bloch-Torrey equation to include variability in diffusivity due to restrictions and hindrances. Using in vivo data from the Humman Connectome Project (HCP), we show that the PICASO model can provide novel information about the microstructural layout of the axonal packing in human brain. Thus, our method can be applied in clinical settings to investigate brain abnormalities. |
| 3089 | Computer #84 |
Simulation study investigating the effect of diffusion, susceptibility, and vessel topology in characterizing normal and tumorous vasculature using R2* |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States, 2Department of Physics, UAE University, Al-Ain, Abu Dhabi, United Arab Emirates |
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Brain vasculature is conventionally represented as straight cylinders when simulating BOLD contrast effects in fMRI. In reality, the vasculature is more complicated with branching and coiling especially in tumors. We applied a cylinder fork model to reflect the bifurcation, tortuosity, and size of vessels and performed simulations to study the effect of the rotation angle (ϕ) on R2* at different bifurcation angles (β), vessel diameters, diffusion constants, and susceptibility values. This model clearly showed an R2* dependence on ϕ, which could potentially be used as a tool to differentiate between normal and tumor vessels. |
| 3090 | Computer #85 |
Anomalous diffusion parameters are sensible to microstructural variations in brain due to aging |
1Department of physics, CNR ISC UOS Roma Sapienza, Rome, Italy, 2Department of anatomical, histological, forensic and of the locomotor system science, Morphogenesis & Tissue Homeostasis, Sapienza University, Rome, Italy, 3MIRCen, CEA/DSV/I2BM, Fontenay-Aux Roses, France, 4Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy |
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We investigated the anomalous diffusion (AD) stretched exponential γ-imaging model to overcome the sensitivity limitations of conventional DTI approach based on the assumption of the Gaussian model with regard of displacements of water molecules in tissues. The benefits of this approach are illustrated with an in-vivo diffusion study of the human brain performed on 18 healthy volunteers in the age range (23-70 years). Mean γ (Mγ) and anisotropic γ (Aγ) maps are obtained and compared with DTI maps. The current study suggests that Mγ and Aγ are more sensitive to micro-structural changes caused by normal aging, compared to DTI metrics. |
| 3091 | Computer #86 |
Diffusion Microstructure Imaging With High-Performance Head-Only Gradient: Preliminary Results |
1GE Global Research, Niskayuna, NY, United States, 2GE Global Research, Munich, Germany, 3Technical University of Munich, Munich, Germany, 4Mayo Clinic, Rochester, MN, United States |
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A high-performance head-only gradient coil (Gmax=80 mT/m, SR=700 T/m/s) allows diffusion imaging at substantially shorter echo-time and echo-spacing than conventional whole-body gradient coil systems. This greatly benefits microstructure imaging with diffusion EPI, providing reduced echo spacing by up-to two-fold and shorter TE by up-to 30%. Imaging results demonstrate reduced distortion and improved white matter SNR. Preliminary results on axonal radius mapping with high b-value imaging (up-to b=12,000 s/mm2) demonstrate the feasibility of 2 mm-isotropic imaging with the head-gradient. |
| 3092 | Computer #87 |
Quantifying White Matter Microstructure with a Unified Spatio-Temporal Diffusion Weighted MRI Continuous Representation |
1Athena, Inria, Sophia-Antipolis, France, 2CENIR, Brain and Spine Institute, Paris, France |
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A current problem Diffusion MRI (dMRI) based microscopy faces under the narrow pulse approximation is how to best exploit the 4D (q-space + diffusion time) nature of the signal. Assaf et al. showed that exploring the dMRI attenuation at different diffusion times provides information on the apparent distribution of axonal diameters within a voxel in their seminal work: AxCaliber1. However, AxCaliber requires knowing beforehand the predominant orientation of the axons within the analyzed volume to adjust the q-space sampling accordingly. In this work, we show that our novel sparse representation of the 3D+t dMRI signal2 enables the recovery of axonal diameter distribution parameters with two main advantages. First, it doesn't require knowledge of the predominant axonal direction at acquisition time. Second, using the hypothesised dMRI signal symmetry, it allows computing the average attenuation on the plane perpendicular to the predominant axonal direction analytically. Hence, it takes advantage of the full 3D+t signal information to fit the AxCaliber model. |
| 3093
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Computer #88 |
Cytoarchitectonic abnormalities along white matter pathways in temporal lobe epilepsy: Combining diffusional kurtosis imaging and automated fiber quantification |
1Medical University of South Carolina, Charleston, SC, United States, 2University of Liverpool, Liverpool, United Kingdom, 3Charleston, SC, United States |
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Temporal lobe epilepsy (TLE) is the most common form of medically refractory epilepsy and is associated with focal brain abnormalities causing recurrent, unprovoked seizures originating from the temporal lobe. However, cytoarchitectronic changes can be detected outside of the temporal lobe and may be associated with the clinical course of the disease. We implement a novel neuroimaging approach which combines the strengths of diffusional kurtosis imaging and automated fiber quantification for the non-invasive characterization of white matter pathways and demonstrate its sensitivity to detect pathological alterations associated with TLE. The proposed technique may provide further insights into the clinicopathology of TLE. |
| 3094 | Computer #89 |
Short-term mindfulness-based stress reduction training increases tract integrity in right auditory radiation and anterior and posterior commissures |
1Graduate Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan, 2Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, 3Department of Buddhist Studies, Dharma Drum Institute of Liberal Arts, New Taipei City, Taiwan, 4Department of Neurology, Cardinal Tien Hospital Yonghe Branch, New Taipei City, Taiwan, 5Department of Mass Communication, Tamkang University, Taipei, Taiwan, 6Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, 7Institute of Medical Device and Image, National Taiwan University College of Medicine, Taipei, Taiwan, 8Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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Mindfulness-based stress reduction (MBSR) is an 8-week mindfulness meditation training which exerts beneficial effects on physical and mental health. Many researches showed that the changes in brain structure were related to mindfulness meditation. However, few studies have investigated the relationships between short-term mindfulness meditation and altered white matter tracts. Therefore, a longitudinal study was designed in this study to identify the effects of 8-week MBSR program on white matter tract integrity. We found that there was significant difference in three white matter tracts, right auditory radiation, anterior commissure and posterior commissure, in the novice practitioners. |
| 3095 | Computer #90 |
A physically-constrained model for diffusion kurtosis imaging |
1Division of Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom, 2Department of Engineering Science, University of Oxford, Oxford, United Kingdom |
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Diffusion kurtosis imaging provides higher-order information about diffusion. However, the quadratic term in the diffusion kurtosis model produces undesirable behaviour at high b-values as a result of the negative tails of the diffusivity distribution. A truncated normal distribution has been proposed to address this in one dimension. This work extends this concept to a multivariate truncated normal distribution, and extends the range of b-values over which kurtosis can be estimated. The proposed model is fit to diffusion data from rat hearts, and yields kurtosis values that are consistent with the DKI model. |
| 3096 | Computer #91 |
Intravoxel Incoherent Motion in Normal Pituitary Gland: Initial Study with Turbo Spin-echo Diffusion-weighted Imaging |
1Radiology, Kagoshima University Medical and Dental Hospital, Kagoshima, Japan, 2Clinical Engineering Department Radiation Section, Kagoshima University Hospital, Kagoshima, Japan, 3Philips Electronics Japan, Tokyo, Japan |
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Our purpose was to evaluate the feasibility of intravoxel incoherent motion (IVIM) assessment based on turbo spin-echo diffusion-weighted imaging (TSE-DWI) in the normal pituitary gland. In a validation study using normal brain white matter (WM), Bland-Altman analyses revealed fair to good agreement with conventional echo-planar-based DWI (EP-DWI) in the true diffusion coefficient (D) and perfusion fraction (f). In 7 volunteers, both D and f in the anterior pituitary lobe were significantly higher than those in WM, being consistent with high microvascular density in the pituitary gland. Results demonstrated that IVIM assessment based on TSE-DWI in the pituitary gland is feasible. |
| 3097 | Computer #92 |
White Matter Asymmetry During Development Using Diffusion Kurtosis Imaging |
1Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich GmbH, Juelich, Germany, 2Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany, 3Translational Brain Research in Psychiatry and Neurology, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany, 4Institute of Neuroscience and Medicine - 3, Forschungszentrum Juelich GmbH, Juelich, Germany, 5Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany, 6JARA - BRAIN, Translational Medicine, Juelich, Germany, 7Child Neuropsychology Section, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany |
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We compare changes in the white matter asymmetry index in conventional fractional anisotropy (FA) and other diffusion kurtosis imaging (DKI) metrics in adults and children. For some fibres, such as cingulate gyrus, hippocampus and superior longitudinal fasciculus, other DKI parameters show significant asymmetry where FA fails. When compared to adults, children showed more laterality in cingulate gyrus, superior longitudinal fasciculus and superior longitudinal fasciculus in temporal parts, which indicate that the degree of asymmetry in these fibres is higher during childhood. |
| 3098 | Computer #93 |
Anisotropy measure from High angular resolution diffusion imaging Data Using Higher Order Diffusion Tensor model |
1Diagnostic & Interventional Imaging, University of Texas at Houston, Houston, TX, United States |
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Different anisotropy indices such as generalized anisotropy (GA) and generalized fractional anisotropy (GFA) for HARDI data have been reported, but they have their own limitations. Here we propose a new anisotropy measure (HFA) for the HARDI data that is rotationally invariant. The new proposed measure is compared with GA and GFA using the contrast-to-noise ratio and coefficient of variation as the metrics for three white matter regions. HFA and GFA have shown better CNR than FA and GA in two and three crossing regions. The results described above were very similar across all the five subjects. |
| 3099 | Computer #94 |
Tract Orientation and Angular Dispersion Deviation Indicator (TOADDI): A framework for single-subject analysis in diffusion tensor imaging |
1Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States, 2National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD, United States, 3The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States |
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The purpose of the proposed framework is to carry out single-subject analysis of diffusion tensor imaging (DTI) data. This framework is termed Tract Orientation and Angular Dispersion Deviation Indicator (TOADDI). It is capable of testing whether an individual tract as represented by the major eigenvector of the diffusion tensor and its corresponding angular dispersion are significantly different from a group of tracts on a voxel-by-voxel basis. This work develops two complementary statistical tests (orientation and shape tests) based on the elliptical cone of uncertainty, which is a model of uncertainty or dispersion of the major eigenvector of the diffusion tensor. |
| 3100 | Computer #95 |
Assessment of brain structural abnormalities and the correlation with inhibitory control in betel nut chewers with DTI |
1Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, 2Department of Psychology, Chung Shan Medical University, Taichung, Taiwan, 3Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan |
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Betel nut is one of the common addictive substances in many countries. The brain influence of cocaine, alcohol, and tobacco cigarette have been studied by several studies. However, only few studies focused on the brain influence of betel nut, and most of them used fMRI or PET. Thus, our study aim was to use diffusion tensor imaging (DTI) to evaluate the impact of neurological structure of white matter caused by betel nut. The brain structural differences between the betel nut chewers and healthy controls and the correlation with inhibitory control were also discussed. Our results pointed out the significant neurological structural differences in the insula, amygdala and putamen of DTI indices between the betel nut chewers and healthy controls. |
| 3101 | Computer #96 |
Assessment of pharmacotherapy effects on APP/PS1 mice brain by Diffusion Spectrum Imaging |
1Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan, 2Institute of Biomedical Engineering, National Taiwan University College of Medicine, Taipei, Taiwan, 3Graduate Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan, 4Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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To determine the effects of a novel neuroprotective drug on white matter integrity in Alzheimer’s disease (AD), generalized fractional anisotropy (GFA) was assessed in mice brains using diffusion spectrum imaging (DSI). The mice included 5 AD mice without medication, 4 AD mice with medication, and 5 control mice. Comparing with the control mice, the AD mice without medication showed significantly increased GFA in the hippocampus and thalamus, whereas the AD mice with medication showed no significant difference. Our findings imply that DSI can be used to monitor the drug effects in AD mice. |
| Exhibition Hall | Monday, May 9, 2016: 17:30 - 18:30 |
| 3102 | Computer #1 |
Accelerated 3D self-gated cardiac cine imaging at 3T using a tiny golden angle and compressed sensing |
1University of Science and Technology of China, Hefei, China, People's Republic of, 2Shenzhen Institutes of Advanced Technology, Shenzhen, China, People's Republic of, 3Cedars-Sinai Medical Center, Los Angeles, CA, United States |
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An accelerated self-gating (SG) technique, SparseSG, was developed to realize whole-heart coverage of 3D cardiac cine imaging at 3T without ECG and breath-holding. Preliminary in vivo study demonstrated that a whole heart coverage of 3D cine imaging can be achieved within 1 min and the technique had excellent performance compared to the standard ECG-triggering and conventional SG methods. |
| 3103 | Computer #2 |
Two-Dimensional Respiratory-Motion Characterization for Continuous MR Measurements Using Pilot Tone Navigation |
1Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, 2Erlangen Graduate School in Advanced Optical Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, 3Magnetic Resonance, Research and Development, Hardware, Siemens Healthcare GmbH, Erlangen, Germany, 4Magnetic Resonance, Product Definition and Innovation, Siemens Healthcare GmbH, Erlangen, Germany |
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Pilot Tone signals, generated by a commercial signal generator and received with standard MR local coils, were analyzed for multidimensional respiratory information. The ground truth for respiratory motion in two orthogonal directions ($$$\boldsymbol{g}_{SI}$$$ and $$$\boldsymbol{g}_{AP}$$$), generated by sagittal image streams of the right liver dome using standard fluoroscopic sequences, showed excellent correlation with the PT signal derived from a separate measurement (for $$$\boldsymbol{g}_{SI}$$$: 0.90 $$$\pm$$$0.13; for $$$\boldsymbol{g}_{AP}$$$: 0.82 $$$\pm$$$0.21). Our results demonstrate that PT navigation can provide two-dimensional characterization of regular and irregular respiratory motion without interfering with the MR measurement. |
| 3104 | Computer #3 |
Fetal Cardiac MRI with self-gated iGRASP |
1Laboratory of Medical Informatics, Department of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece, 2Lund Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, Lund University, Lund, Sweden, 3Department of Diagnostic Radiology, Skåne University Hospital, Lund University, Lund, Sweden, 4Siemens Healthcare AB, Malmoe, Sweden, 5Department of Obstetrics and Gynecology, Skåne University Hospital, Lund University, Lund, Sweden |
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The aim of this study was to demonstrate the feasibility of CINE fetal MRI within a breath-hold with self-gated retrospective binning applied with continuous golden angle radial sampling and iGRASP acceleration. A bSSFP radial acquisition scheme was applied with 0.7x0.7mm2 in-plane resolution and a small golden angle of 23.1o. A total of 3800 radial spokes were acquired within a breath hold of 15s. Cardiac triggering was obtained from the centers of the readouts via Principal Component Analysis. The final images were obtained by using iGRASP. Good quality CINE images from the fetus in the third trimester were acquired. |
| 3105 | Computer #4 |
Cardiac Phase-Resolved B1 Mapping at 3T |
1Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States, 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 3Computer Assisted Clinical Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany |
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For various cardiac MRI appications, having B1 maps that are cardiac phase-resolved may be beneficial at high fields. In this work, we developa retrospectively ECG-gated sequence based on the actual flip angle imaging technique for 2D cardiac phase-resolved B1 mapping at 3T. |
| 3106 | Computer #5 |
CMR Assessment of an Isoproterenol Infusion Mouse Model of Myocardial Hypertrophy and Fibrosis |
1Bristol Myers Squibb, Princeton, NJ, United States, 2Bristol Myers Squibb, Hopewell, NJ, United States, 3Bristol Myers Squibb, Wallingford, CT, United States |
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Recent advances in cardiovascular MRI (CMR) technologies such as T1-mapping or extracellular volume (ECV) fraction (derived from T1-mapping) offer robust techniques to assess diffuse fibrosis in patients with myocardial infarction and heart failure. In the present study, CMR assessment of myocardial fibrosis and hypertrophy was evaluated in an isoproterenol infusion model in Balb/c mice. The CMR techniques including T1-mapping and the ECV quantification provide a translational non-invasive imaging marker to assess diffuse myocardial fibrosis, and the potential to evaluate efficacy of anti-fibrosis treatment. |
| 3107 | Computer #6 |
Gamma Knife Radiosurgery Treatment of in Vivo Rabbit Model Aneurysms |
1Neurosurgery, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, 2Radiology, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, 3Comparative Medicine, The Pennsylvania State University - College of Medicine, Hershey, PA, United States |
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Current treatment options for un-ruptured intracranial aneurysms typically include open clipping, endovascular embolization, or observation. We undertook this study to examine the effects of GKRS on an in vivo rabbit aneurysm model. Involution of aneurysms after GKRS could provide a safer and more cost-effective treatment alternative for patients harboring un-ruptured intracranial aneurysms. The results of the study reveal a 40 percent reduction in aneurysm total volume, internal volume, and surface area over the 24-month period. Targeted GKRS is successful in promoting histological and hemodynamic changes to the rabbit carotid aneurysm, linearly reducing size over time. |
| 3108 | Computer #7 |
Assessment of longitudinal reproducibility of mice LV functional parameters @11.7T derived from self-gated CINE MRI |
1Department of Cardiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China, People's Republic of, 2Department of Internal Medicine II, University Hospital Ulm, Ulm, Germany, 3Core Facility Small Animal MRI, Medical Faculty, Ulm University, Ulm, Germany |
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Cardiovascular magnetic resonance (CMR) has emerged as the most accurate imaging modality for noninvasive assessments of left ventricular (LV) structure and function in mice. However, data on the longitudinal variability of LV systolic function assessment in mice is still limited. In this contribution, a one year follow-up of the longitudinal reproducibility of the LV function and mass has been performed at 11.7T with self-gated CINE MRI. The investigated protocol was proven reliable for the evaluation of EF, EDV, ESV, SV and LVM data. |
| 3109 | Computer #8 |
In Vivo Cardiac DTI on a 3T Clinical Scanner: An Optimized M2 Approach |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2MR R&D, Siemens Healthcare, Los Angeles, CA, United States, 3Siemens Healthcare GmbH, Erlangen, Germany, 4Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 5Bioengineering, University of California Los Angeles, Los Angeles, CA, United States |
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Optimized second order motion compensated (M2) diffusion tensor prepared cardiac magnetic resonance (DT-CMR) was applied in healthy volunteers and heart failure patients at 3T. The pulse sequence design focused on B1 robustness at high main field. In healthy volunteers, the proposed M2 DT-CMR was compared to zero order (M0) and first order (M1) motion compensations. In addition, heart rate dependency of the proposed M2 DT-CMR was explored with contextual comparison to M0 and M1. M2 DT-CMR was the only technique capable of application in heart failure patients without bulk motion artifacts. |
| 3110 | Computer #9 |
Comparison Between Spin Echo and Stimulated Echo Diffusion Encoding for Diffusion-Weighted Cardiac Magnetic Resonance (DW-CMR) at 3T |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Siemens Healthcare GmbH, Erlangen, Germany, 3Siemens Healthcare, Los Angeles, CA, United States, 4Bioengineering, University of California Los Angeles, Los Angeles, CA, United States |
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Clinical application of diffusion-weighted cardiac magnetic resonance (DW-CMR) has demonstrated promise in detecting and characterizing the tissue microphysiology and/or microstructure. The aim of this study is to compare a recently developed SE diffusion-prepared approach with a conventional STE DW-CMR technique in normal volunteers on a 3T system. M2-SE derived MD values were significantly higher than STE derived values despite the same prescribed b-value and the difference is not dependent on heart rate. Both DW-CMR techniques were reproducible and motion corruption was seen to be overall less in M2-SE. |
| 3111 | Computer #10 |
Diffusion Tractography of the Entire Heart using Free-Breathing Accelerated Simultaneous Multislice Imaging |
1Harvard Medical School - Massachusetts General Hospital, Boston, MA, United States, 2University of São Paulo, São Paulo, Brazil, 3Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States, 4Siemens Healthcare, Boston, MA, United States |
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We introduce an approach to perform free-breathing DTI and tractography of the whole heart based on simultaneous multislice excitation, sequential reordering of the diffusion-encoding gradients, combined with a retrospective entropy-based image alignment and selection method. The approach was tested in 7 healthy volunteers, in whom breath-hold and free-breathing scans were performed. Coherent tracts of the entire heart could be derived in all cases, and no significant differences were seen in mean diffusivity, fractional anisotropy, or myofiber helix angle. Accelerated free-breathing DTI of the entire heart could be performed in less than 15 minutes without significant loss of image quality. |
| 3112 | Computer #11 |
Transmural heterogeneity of in-vivo whole heart diffusion parameters: architecture, physiology or artifact? |
1Radiology, UMC Utrecht, Utrecht, Netherlands, 2Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, 3Radiology, AMC Amsterdam, Amsterdam, Netherlands, 4Biomedical Engineering & Physics, AMC Amsterdam, Amsterdam, Netherlands |
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A recent study by McGill et al. showed in-vivo spatial and transmural heterogeneity of cardiac diffusion parameters. The aim of this study was to investigate the origin of DWI-parameter heterogeneity using whole heart in- and ex-vivo SE-DWI. Based on our results, transmural heterogeneity is partially explained by variations in transmural and spatial perfusion signal fraction and, partially seems to have its origin in cardiac architecture during systole. |
| 3113 | Computer #12 |
Comprehensive comparison of in- and ex-vivo whole heart fiber architecture: similar yet different |
1Radiology, UMC Utrecht, Utrecht, Netherlands, 2Biomedical Engineering & Physics, AMC Amsterdam, Amsterdam, Netherlands, 3Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, 4Radiology, AMC Amsterdam, Amsterdam, Netherlands |
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The aim of this study was to provide a comprehensive description of whole heart in-vivo myocardial fiber architecture using the fiber architecture matrix, and to validate results using ex-vivo and simulated data. We showed that whole heart fiber architecture described by the FAM can be obtained from in-vivo DWI. However, compared to ex-vivo data the direction of ε2 and ε3 are exchanged. |
| 3114 | Computer #13 |
Second-order motion-compensated spin echo diffusion tensor imaging of the in vivo human heart – considerations on gradient performance requirements |
1King's College London, London, United Kingdom, 2University and ETH Zurich, Zurich, Switzerland |
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In vivo cardiac DTI using spin-echoes has been demonstrated on MR systems equipped with powerful gradients. In this study we investigate the dependency of helix and transverse angle error on maximum gradient amplitude for second order motion compensated diffusion encoding of the in-vivo heart. Root-mean-square errors for helix and transverse angles were 15.0±3.7°, 11.0±1.8°, 10.3±2.4°, and 11.7±3.8°, 9.0±2.0°, 8.1±2.2° for gradient strengths of 30mT/m, 40mT/m and 60mT/m when compared to data obtained at 74.5 mT/m gradient strength. From the data it is concluded that second order motion compensated diffusion encoding allows for in vivo cardiac DTI even on MR systems with standard gradient amplitudes of 40 mT/m. |
| 3115 | Computer #14 |
A comparison of M012 compensated spin-echo and STEAM cardiac DTI at multiple cardiac phases |
1Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield Foundation NHS Trust, London, United Kingdom, 2National Heart and Lung Institute, Imperial College London, London, United Kingdom, 3National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States |
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In-vivo cardiac diffusion tensor imaging (cDTI) performed with a stimulated echo (STEAM) sequence is considered strain sensitive and low SNR. Alternatively, motion compensated spin-echo (M012-SE) sequences are thought to be strain insensitive and high SNR, but suffer from long echo times and short mixing times. In this work we compare the reliability of and the cDTI parameters derived from STEAM and M012-SE data in 20 volunteers at mutliple points in the cardiac cycle on a standard clinical scanner. We show systematic differences between the sequences and show that there are few correlations between these differences and strain and/or T1/T2. |
| 3116 | Computer #15 |
Convex Optimized Diffusion Encoding (CODE) Gradient Waveforms for Bulk Motion Compensated Cardiac Diffusion Weighted MRI |
1Radiological Sciences, UCLA, Los Angeles, CA, United States, 2Biomedical Physics IDP, UCLA, Los Angeles, CA, United States |
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Bulk motion compensated diffusion encoding is critical for accurately measuring diffusion in the heart. However, the diffusion encoding gradient waveforms required to suppress bulk motion artifacts can extend TE and limit SNR. We have developed a Convex Optimized Diffusion Encoding (CODE) framework to design time-optimal, motion compensated diffusion encoding gradients that remove sequence dead times and minimize TE. CODE gradients were designed and implemented for cardiac DWI on a 3.0T clinical scanner in healthy volunteers and patients. CODE reduced bulk motion artifacts compared with conventional monopolar encoding. |
| 3117 | Computer #16 |
Right Ventricular Myofiber Architecture |
1Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States, 2Departments of Cardiology and Pathology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States |
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While the left ventricle (LV) myofiber architecture has been studied extensively, there have been fewer studies of right ventricle (RV) myofiber architecture, and there is no established convention for reporting RV myofiber anatomy. Establishing the normal RV myofiber architecture is critical to facilitate our understanding of the impact of congenital microstructural defects in diseased hearts. In this work, we fixed a juvenile swine heart and imaged it with magnetic resonance diffusion compartment imaging (MR-DCI). We describe the detailed myofiber pattern of the RV with both MR-DCI and stained histological microscopy, and propose a standardized convention for describing the myofiber anatomy. |
| 3118 | Computer #17 |
Mapping Dynamic Myocardial Fibre Reorientation in Dilated Cardiomyopathy using Dual-Phase In-Vivo Cardiac Diffusion Tensor Imaging |
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 2Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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In vivo cardiac diffusion tensor imaging (DTI) was employed to study dynamic alterations of myocardial microstructure in patients with dilated cardiomyopathy (DCM) relative to healthy controls using dual-phase cardiac DTI. A reduction in dynamic change of fiber orientation between diastole and systole compared to the controls was observed. Steeper diastolic helix angles in DCM patients relative to controls were associated with a larger pre-stretch of the left ventricle. It is speculated that this larger pre-stretch alongside with reduced myocyte shortening compromises the ability to dynamically reorient fiber aggregates during systolic contraction. |
| 3119 | Computer #18 |
Assessing non-Gaussian diffusion in cardiac tissue |
1Division of Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom, 2Department of Engineering Science, University of Oxford, Oxford, United Kingdom |
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Non-Gaussian diffusion MRI allows the quantification of diffusion signals that deviate from mono-exponential decay. In cardiac MRI, very little has been reported on non-Gaussian models. In this work, the diffusion tensor, stretched exponential, bi-exponential, and diffusion kurtosis models were fit to data from fixed rat hearts. Performance was measured using the Akaike Information Criterion (AIC). All models demonstrated the presence of non-Gaussian diffusion, particularly in the right ventricle. The bi-exponential model fit the data best and had the lowest AIC. Non-Gaussian diffusion was greater perpendicular, rather than parallel, to cardiac fibers, corresponding to greater restrictions to diffusion. |
| 3120 | Computer #19 |
Quantification of residual motion in diffusion-weighted cardiac MR (DW-CMR): objective quality metrics and validation using 3 diffusion encoding schemes under free breathing conditions. |
1CREATIS, Université de Lyon ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Claude Bernard Lyon 1, Lyon, France, 2Siemens Healthcare France, Paris, France, 3Department of Radiology, Centre Hospitalier Universitaire de Saint- Etienne, Université Jean-Monnet, Saint-Etienne, France |
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DW-CMR remains challenging due to respiratory and heart motion. Recent developments in cardiac diffusion imaging proposed Acceleration Motion Compensation (AMC) spin echoes encoding scheme to tackle cardiac motion. In addition, free breathing acquisition with prospective motion correction like slice following technique has been shown to reduce efficiently and significantly the scan time. Here, we proposed a method to quantify the remaining cardiac or breathing motion corruption in DW-CMR measurement and we evaluated it using 3 diffusion encoding scheme: AMC, Stjekal-Tanner and Twice Refocused Spin Echo. Error maps were also compared to physiological motion indicators: cardiac motion using strain measurement and breathing phase using navigator information. |
| 3121 | Computer #20 |
Physiological Parameters Measurements of Normal and Infarcted Myocardium with Ultrasound and MR imaging |
1Gladstone Institute, San Francisco, CA, United States, 2UCSF, San Francisco, CA, United States, 3Radiology, UCSF, San Francisco, CA, United States |
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In this study we compared two in vivo imaging techniques to obtain anatomical and physiological parameters of mice hart. Our results suggest that measurements of enjection fraction and mass of left ventricle were easier and cheaper with ultrasound echocardiography however evaluation of a scar tissue and re-muscularization of infarcted myocardium are only possible with MRI method |
| 3122 | Computer #21 |
Applying Origami Coil Design for Deployable Intra-cardiac MRI Catheter |
1Engineering, The University of Georgia, Athens, GA, United States, 2Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States, 3Medicine, The University of Georgia, Athens, GA, United States |
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Catheter ablation is a common electrophysiological (EP) procedure to treat irregular heart rhythm conditions, such as atrial fibrillation. Catheter ablation can be assisted through the use of imaging coils under magnetic resonance imaging (MRI) which provides a roadmap for preoperative preparation and intraoperative catheter navigation. Intra-cardiac imaging coils allow for ablated lesions to be observed in real time with excellent soft tissue contrast, providing electrophysiologists better control over the result of the procedure. We present a novel catheter design which integrates a unique origami deployable mechanism for enabling parallel MR imaging in MRI guided EP procedures. |
| Exhibition Hall | Monday, May 9, 2016: 17:30 - 18:30 |
| 3123 | Computer #25 |
Short-breath hold cine DENSE |
1NIHR funded Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom, 2National Heart and Lung Institute, Imperial College London, London, United Kingdom, 3National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States, 4MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, 5University of Virginia, Department of Biomedical Engineering, Charlottesville, VA, United States |
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Displacement encoding with stimulated echoes (DENSE) can provide valuable strain information, but acquisitions are typically too long for patient cohorts who have difficulty breath holding. In this work we accelerate 2D cine spiral DENSE acquisitions by selectively exciting a small field of view around the heart. We compare strain data derived from DENSE acquired with unaccelerated and up to 2.5x acceleration in a cohort of healthy subjects and show minimal differences when the acquisition is accelerated. We also show an example from a patient with a myocardial infarction where the accelerated DENSE data shows abnormal strain in the infarcted regions. |
| 3124 | Computer #26 |
Biventricular Cardiac Mechanics in Healthy Subjects using 3D Spiral Cine DENSE and Mesh-Free Strain Analysis |
1Institute for Advanced Application, Geisinger Health System, Danville, PA, United States, 2Pediatrics, University of Kentucky, Lexington, KY, United States, 3Biomedical Engineering, University of Kentucky, Lexington, KY, United States, 4Electrical Engineering, University of Kentucky, Lexington, KY, United States |
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Cardiac mechanics have been extensively characterized in the left ventricle (LV). However, the right ventricle (RV) is rarely studied due to both acquisition and post-processing challenges. In this study, we combined 3D displacement-encoded (DENSE) imaging with custom post-processing that utilizes a local coordinate system to extract advanced measures of cardiac mechanics in an effort to characterize healthy biventricular function. We found that torsion as well as circumferential and longitudinal strain vary throughout the RV, but globally were comparable to their LV counterparts. This data can be used to better understand how biventricular function is disrupted by disease. |
| 3125 | Computer #27 |
Myocardial Strain Analysis With CMR in Breast Cancer Patients with Iatrogenic Cardiotoxicity Using Heart Deformation Analysis: Comparison to DENSE |
1Northwestern University Feinberg School of Medicine, Chicago, IL, United States, 2Radiology, Northwestern University, Chicago, IL, United States, 3Cardiovascular MR R&D, Siemens Healthcare, Chicago, IL, United States, 4Cardiology, Northwestern University, Chicago, IL, United States |
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Strain imaging at cardiac MR has been shown to be a powerful tool in the pre-clinical detection of early cardiac dysfunction in the heart failure population, but has been only minimally studied in cardiotoxicity patients. This study evaluated a semi-automatic heart deformation analysis (HDA) tool in the assessment of left ventricular myocardial strain in patients with known cardiotoxicity, and found very good to excellent agreement with global strain values calculated using displacement encoding with stimulated echoes (DENSE). HDA analysis of conventional cine sequences has the potential to play a significant role in the evaluation of patients at risk for cardiotoxicity. |
| 3126 | Computer #28 |
Free-breathing 2D cine DENSE MRI using localized signal generation, image-based navigators, motion compensation and compressed sensing |
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 2Medical Imaging Technologies, Siemens Healthcare, Princeton, NJ, United States, 3University of Virginia, Charlottesville, VA, United States, 4Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, United States |
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Current cine DENSE protocols require breath-holding, which limits the use of this technique to patients with good breath-holding capabilities and excludes many pediatric and heart failure patients. To accomplish free-breathing scans with high efficiency and quality, we developed a 2D cine DENSE acquisition and reconstruction framework that utilizes localized signal generation, image-based self-navigated motion estimation, k-space motion correction and compressed sensing. Reconstructions and Bland-Altman analysis from 5 volunteers demonstrated that the proposed method recovered high-quality images and strain data from free-breathing data, showing better agreement than conventional reconstructions of the same data with breath-holding scans. |
| 3127 | Computer #29 |
Effect of Respiratory Suspension on the Computation of Left Ventricular (LV) Volume and Rate of Volume Change (dV/dt)-based Diastolic Indices with Echocardiography as a Reference |
1Phillips Healthcare, Cleveland, OH, United States, 2Diagnostic and interventional Radiology, CHI St Luke's Health, Houston, TX, United States, 3Diagnostic and Interventional Radiology, CHI St Luke's Health, Houston, TX, United States |
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Diastolic functional indices based on trans-mitral blood flow velocities are pre-load dependent and early diastolic filling can be diminished by activities such as inspiration or Valsalva maneuver. Cardiac cine MR images are typically acquired during suspended respiration and thus could induce systemic bias. In this study, we evaluate the impact of respiratory suspension on the computation of volume-based diastolic indices using peak velocity-based Doppler echo measurements as the reference. The volume based diastolic indices derived from high temporal resolution cine MR correlated well with velocity based E/A ratio from echo while indicating the direct impact of respiratory suspension. |
| 3128 | Computer #30 |
Peak Filling Rates assessed by Cardiac Magnetic Resonance Imaging indicate Diastolic Dysfunction from Myocardial Iron Toxicity |
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 2Biochemistry, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 3Department of Radiology, UCSF Benioff Children's Hospital Oakland, Oakland, CA, United States, 4Department of Pediatric Hematology/Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 5Siemens Healthcare, Hamburg, Germany |
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The diastolic peak filling rate ratio (PFRR) is a sensitive marker to indicate diastolic dysfunction from myocardial iron toxicity in patients with systemic iron overload disease. Precise assessment of the PFRR by CMR requires a volumetric approach with exclusion of trabeculae and papillary muscles from the LV cavity. The PFRR assessed by CMR may be a valuable parameter for the screening and monitoring of myocardial iron toxicity due to iron deposition in patients with preserved systolic function. |
| 3129 | Computer #31 |
Exercise stress cardiac MR assessment of diastolic function in healthy volunteers and pulmonary hypertension |
1Radiology, University of Wisconsin- Madison, Madison, WI, United States, 2Biomedical Engineering, University of Wisconsin- Madison, Madison, WI, United States, 3Medical Physics, University of Wisconsin- Madison, Madison, WI, United States |
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Dyspnea on exertion is a common manifestation of systolic and diastolic heart failure. Using an MRI-compatible exercise device allowing subjects to exercise while in the bore of the scanner, we assessed exercise-induced changes in diastolic transmitral flow in younger and older healthy volunteers and subjects with pulmonary hypertension. The measurements we obtained demonstrated decreased E/A ratios for older healthy volunteers and PH subjects when compared to younger healthy volunteers, however these differences were not statistically significant. |
| 3130 | Computer #32 |
Quantitative, Time-efficient, Heart-Rate Independent Myocardial BOLD MRI with Whole-heart Coverage at 3T in a Canine Model of Coronary Stenosis with Simultaneous 13N-Ammonia PET Validation |
1Cedars Sinai Medical Center, Los Angeles, CA, United States, 2Lawson Health Research Institute, london, ON, Canada, 3Siemens Healthcare, Los Angeles, CA, United States, 4IMT Institute for Advanced Studies Lucca, Lucca, Italy |
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Current myocardial BOLD MR methods are limited by: (a) poor spatial coverage and imaging speed; (b) imaging confounders; and (c) imaging artifacts, particularly at 3T. To address these limitations, we developed a heart-rate independent, free-breathing 3D T2 mapping technique at 3T that utilizes near 100% imaging efficiency, which can be completed in 3 minutes with full LV coverage. We tested our method in a canine model of coronary stenosis and validated our findings with simultaneously acquired13N-ammonia PET perfusion data in a whole-body PET/MR system. |
| 3131 | Computer #33 |
Spiral SPIRIT Tissue Phase Mapping enables the acquisition of myocardial motion with high temporal and spatial resolution during breath-hold |
1University Medical Center Freiburg, Dept. of Radiology - Medical Physics, Freiburg, Germany, 2University-Heart Center Freiburg, Cardiology und Angiology I, Freiburg, Germany, 3University Hospital Bern, Institute of Diagnostic, Interventional and Pediatric Radiology, Bern, Switzerland |
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MR Tissue Phase Mapping (TPM) is a powerful approach to assess left ventricular (LV) function. Conventional Cartesian acquisition-strategies with k-t-based parallel imaging acceleration allow the acquisition of a single slice within a breath-hold, but suffer from low spatial resolution. In this work a comparison with undersampled high-resolution spiral SPIRIT TPM for different trajectory designs within one breath-hold and free breathing Cartesian k-t-accelerated PEAK TPM is presented. High image quality, comparable peak velocity values and time to peaks of spiral SPIRIT TPM for high resolution within a breath-hold might enhance myocardial functional analysis. |
| 3132 | Computer #34 |
Comparison Between Radial and Cartesian Sampling Patterns in Accelerated Real-Time Cardiac Cine MRI |
1Physics, University of Utah, Salt Lake City, UT, United States, 2Radiology, UCAIR, University of Utah, Salt Lake City, UT, United States, 3Internal Medicine, Division of Cardiology, University of Utah, Salt Lake City, UT, United States, 4School of Medicine, Radiology, New York University, New York, NY, United States, 5Bioengineering, University of Utah, Salt Lake City, UT, United States |
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To date, no study has compared 12-fold accelerated real-time cine MRI with compressed sensing (CS) between Cartesian and radial k-space sampling schemes. We sought to compare their performance in patients and volunteers. We compared point spread functions (PSF) to determine which sampling pattern generates more incoherent aliasing artifacts. We also compared their performance in a group of 15 patients and one volunteer, where 3-fold accelerated product real-time MRI was used as reference. Two cardiologists independently graded images from each subject. PSF analysis showed that radial produces more incoherent aliasing artifacts. Image quality was better for radial than Cartesian sampling schemes. |
| 3133 | Computer #35 |
Wideband Cardiac MR Perfusion Pulse Sequence for Imaging Patients with implantable cardioverter defibrillator |
1Radiology, UCAIR, University of Utah, Salt Lake City, UT, United States, 2Bioengineering, University of Utah, Salt Lake City, UT, United States |
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Patients with end-stage heart failure (HF) often require advanced therapeutics, but current clinical profiles and biomarkers are not adequate for predicting outcomes. Myocardial perfusion reserve may be an important predictor, but it is technically challenging to perform perfusion MRI in patients with end-stage HF because they often have implantable cardioverter defibrillator (ICD), which generates significant image artifacts. We developed a novel cardiac perfusion pulse sequence using a wideband saturation pulse. Compared with standard perfusion MRI, wideband perfusion MRI suppresses image artifacts induced by ICD. |
| 3134 | Computer #36 |
Feature tracking imaging (FTI) for right ventricular strain assessment in patients with chronic thromboembolic pulmonary hypertension (CTEPH) |
1Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 2Division of Cardiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan |
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Right ventricular (RV) function has a significant impact on the prognosis of chronic thromboembolic pulmonary hypertension (CTEPH), as it does with other forms of pulmonary arterial hypertension (PH). In this study, we demonstrated that feature tracking imaging (FTI) is fast, simple, and has potential for clinical use for assessing RV strain in CTEPH. The global longitudinal strain (GLS) showed better correlation with the RV ejection fraction (RVEF) and mean pulmonary artery pressure (mPAP). FTI-derived strain measurement might offer a modality for good detection of RV dysfunction and repeatable monitoring after therapeutic intervention. |
| 3135 | Computer #37 |
Cardiac MR Assessment of Diastolic Function |
1Radiology, University of Wisconsin- Madison, Madison, WI, United States, 2Cardiology, Univesity of Wisconsin-Madison, Madison, WI, United States, 3Radiology, Northwestern University, Chicago, IL, United States |
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Diastolic dysfunction is the primary cause of CHF in 40-60% of patients with heart failure in the United States and has been shown to lead to poor outcomes. Early diagnosis and treatment of the causes of diastolic dysfunction is effective in relieving symptoms and reducing mortality. The non- invasive methods which can be used to assess diastolic function include cardiac magnetic resonance (CMR) imaging. The purpose of this educational poster is to describe the CMR techniques which can be used to evaluate diastolic function and review the CMR findings of this disorder. |
| 3136 | Computer #38 |
Finite Element Digital Image Correlation for Cardiac Strain Analysis from 3D Whole-Heart Tagging |
1École Polytechnique, Palaiseau, France, 2Institute for Biomedical Engineering, ETHZ, Zurich, Switzerland, 3KCL, London, United Kingdom, 4ETHZ, Zurich, Switzerland, 5MSU, East Lansing, MI, United States, 6UCSF, San Francisco, CA, United States |
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The objective of the present work was to develop, validate and analyze a finite element digital image correlation approach of extracting ventricular strain data from MR images, which can be applied to both 3D CSPAMM images and conventional multi-slice cine images. Cine and 3D CSPAMM data was acquired on a normal human volunteer, and analyzed. The proposed method provided similar circumferential strain data compared to already validated SinMod method. In contrast to strain mapping from cine images, strain mapping from 3D CSPAMM images captures ventricular twist and torsion in agreement with physiological values, and is less sensitive to image misregistration. |
| 3137 | Computer #39 |
A data analysis framework to study remodeling after myocardial infarction |
1U947, Inserm, Nancy, France, 2IADI, Université de Lorraine, Nancy, France, 3CIC-IT 1433, Inserm, Nancy, France, 4Pôle imagerie, CHRU de Nancy, Nancy, France, 5Pôle S2R, CHRU de Nancy, Nancy, France |
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A data analysis framework is proposed to study the relation between scar severity and regional myocardial function during the process of remodeling after acute myocardial infarction (MI). The framework includes registration steps to correct for slice-to-slice inconsistencies, to align cine with late gadolinium enhancement (LGE) data and to align data from follow-up scans. The framework was evaluated in 114 patients with CMR scans within 3 days after MI and at 6 months. Registration accuracy was below 3 mm. Results show that function at 6 months was inversely associated with scar transmuraltiy at both 3 days and 6 months. |
| 3138 | Computer #40 |
High-resolution MR Imaging of Left-ventricular Function in Newborn Mice |
1Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom, 2Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, United Kingdom |
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The neonatal mouse heart has been reported to regenerate following myocardial injury during the first days of life. Research into this regenerative capability is being actively pursued for translation into the clinic. This study presents cardiac cine imaging of one-day old mice using retrospectively gated, accelerated MR imaging with recovery. Images were acquired with 78x78x500 μm resolution. Left ventricular functional parameters were derived from the images and are presented. This proof of concept study demonstrates that cardiac functional MR imaging with recovery in newborn mice is practical. It also allows the investigation of myocardial regeneration during the first days of life. |
| 3139 | Computer #41 |
Fast myocardial perfusion mapping in mice using heart cycle dependent data weighting |
1Experimental Physics V, University of Wuerzburg, Wuerzburg, Germany, 2NeuroImaging Centre, Ruhr University, Bochum, Germany, 3Department of Internal Medicine 1, Universitaetsklinikum Würzburg, Wuerzburg, Germany |
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A fast method for the measurement of myocardial perfusion in mice is presented. Using an efficient retrospective data selection and weighting process in combination with a model based reconstruction perfusion maps can be acquired within 3.5min. |
| 3140 | Computer #42 |
A preliminary study of Intravoxel Incoherent Motion MR for quantitative evaluation of myocardial perfusion in diabetes and/or hypertension |
1Radiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China, People's Republic of, 2Dalian, China, People's Republic of |
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Myocardial microcirculation perfusion dysfunction plays an important role in assessment cardiac disease especially diabetes and hypertension because of their high incidence in the world. We preliminarily investigated the difference of myocardial micro-vascular perfusion between patients with diabetes/hypertension and normal volunteers with IVIM (0, 20, 50, 80, 120, 150, 200, 300, 500 s/mm2) diffusion weighted imaging. We found that Fast ADC values in patients were significant lower than in healthy volunteers. We concluded that IVIM CMR could quantitatively and noninvasively evaluate perfusion status in patients with diabetes and/or hypertension. |
| 3141 | Computer #43 |
A Computational Fluid Dynamics Simulation Study on the Influence of the Tortuosity of the Coronary Arteries on Contrast Agent Bolus Dispersion in Contrast-Enhanced Myocardial Perfusion MRI |
1Section of Medical Physics, Department of Radiology, Johannes Gutenberg University Medical Center, Mainz, Germany, 2Department of Cellular and Molecular Imaging, Comprehensive Heart Failure Center (CHFC), Wuerzburg, Germany |
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The dispersion of the contrast agent bolus at T1-weighted contrast-enhanced first-pass myocardial perfusion MRI was examined by means of computational fluid dynamics simulations. In this study simulations in idealized coronary artery geometries with different extent of vessel tortuosity and in a straight reference vessel geometry have been performed for the condition of rest and stress. The contrast agent bolus dispersion was larger at rest compared to stress. Furthermore, a negative correlation between the extent of tortuosity and the contrast agent bolus dispersion was found. |
| 3142 | Computer #44 |
Myocardial ASL Perfusion Imaging using MOLLI |
1Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, United States, 2Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States |
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Modified Look-Locker Inversion Recovery (MOLLI) provides the highest precision and reproducibility for myocardial T1 mapping, and extracellular volume (ECV) mapping. In this work, we determine its effectiveness for measuring myocardial blood flow (MBF), based on apparent-T1 mapping under two conditions, slice-selective inversion and non-selective inversion. We demonstrate that MOLLI provides measured MBF comparable to the reference FAIR-SSFP ASL method. |
| 3143 | Computer #45 |
High-resolution myocardial perfusion imaging with radial simultaneous multi-slice imaging and constrained reconstruction |
1Radiology, University of Utah, Salt Lake City, UT, United States |
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High-resolution myocardial perfusion imaging offers improved delineation of subendocardial ischemic regions and can lead to improved diagnosis. Here we use undersampled radial simultaneous multi-slice (SMS) acquisitions in conjunction with constrained reconstruction with temporal total variation and spatial block-matching 3D (BM3D) constraints to obtain high in-plane spatial resolution perfusion imaging. Promising results are shown with two types of myocardial perfusion acquisitions (i) a set of 3 simultaneous slices after a saturation pulse, repeated several times per beat at different cardiac phases, and (ii) a ‘hybrid’ perfusion acquisition with one saturation pulse per beat and the reconstructed cardiac phase of the 3 slices chosen retrospectively. |
| 3144 | Computer #46 |
3D first-pass myocardial perfusion stack-of-stars imaging using balanced steady state free precession |
1NHLI, Imperial College London, London, United Kingdom, 2NIHR Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom, 3UC Berkeley, Berkeley, CA, United States, 4Advanced MRI Technologies, Sebastopol, CA, United States, 5UCAIR, University of Utah, Salt Lake City, UT, United States |
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A method for enabling a balanced steady-state free precession 3D stack-of-stars approach to whole-heart first-pass myocardial perfusion imaging is investigated. Consideration is made of the impact of potential off-resonance effects at 3T and sequence-based modifications to rectify this are examined. Demonstration of the feasibility of this approach is then performed in-vivo. |
| 3145 | Computer #47 |
Double-gated Myocardial ASL Perfusion Imaging provides Insensitivity to Heart Rate Variation |
1Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, United States, 2Department of Medicine, Divison of Cardiology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States, 3Department of Radiology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States, 4Department of Cardiothoracic Surgery, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States, 5Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States |
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Double-gating in myocardial ASL allows for variations in the post-labeling delay in order to ensure that both labeling and imaging occur in the same cardiac phase. Originally proposed by Poncelet et al. in 1999, this was believed to provide insensitivity to heart rate variation. Despite this, most groups have utilized single-gating with a fixed post-labeling delay for pairs of control and tagged images, since this allows for simpler quantification of myocardial blood flow. In this study, we demonstrate that the double-gating is indeed more robust to heart rate variation compared to single-gating for myocardial ASL, based on experiments in healthy volunteers and heart transplant recipients. |
| 3146 | Computer #48 |
Demonstration of Velocity Selective Myocardial Arterial Spin Labeling |
1Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, 2Electrical Engineering, University of Southern California, Los Angeles, CA, United States |
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Arterial spin labeled CMR is a non-contrast myocardial perfusion imaging technique capable of assessing coronary artery disease. A limitation of current methods is potential underestimation of blood flow to myocardial segments that have coronary arterial transit time longer than 1 R-R, which are found in regions with significant collateral development from chronic myocardial ischemia. In this work, we demonstrate the feasibility of a velocity selective labeling scheme for ASL-CMR that is insensitive to arterial transit time. |
| Exhibition Hall | Monday, May 9, 2016: 17:30 - 18:30 |
| 3147 | Computer #49 |
Modified Look-Locker Inversion Recovery (MOLLI) $$$T_1$$$ Mapping with High Precision Composite Inversion Group (IG) Fitting |
1Medical Imaging, University Health Network, Toronto, ON, Canada, 2Medical Imaging, University of Toronto, Toronto, ON, Canada |
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The MOLLI $$$T_1$$$ mapping technique has been used to characterize a variety of cardiac pathologies. However, a significant limitation of this technique is the requirement for rest periods between inversion groups. This increases scan time, and limits the choice of possible inversion groups. A new technique, inversion group (IG) MOLLI fitting, has been recently shown to eliminate the requirement for rest periods, and permits complete flexibility of inversion group selection. However, a significant limitation of this technique is that the resulting $$$T_1$$$ maps have low precision. In this study, a method is presented for high precision IG fitting. |
| 3148 | Computer #50 |
Systolic Myocardial T1- and ECV-Mapping using Saturation-Recovery at 3 Tesla |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, 2DZHK (German Centre for Cardiovascular Research) partner site Mannheim, Mannheim, Germany, 3Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States, 4Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 5Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, 61st Department of Medicine Cardiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany |
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Partial volume artifacts in myocardial T1-mapping are a major source of quantification inaccuracy. In this study, saturation-recovery T1-mapping at 3T was adapted to allow for systolic imaging in order to take advantage of the increased myocardial wall thickness. Estimated T1- and ECV- values for SR T1-mapping during systole were 1554±3ms/0.29±0.03 compared to 1581±35ms/0.31±0.04 at diastole. In conclusion, our results show that SR T1-mapping in systole might be an alternative to derive T1- and ECV-values with reduced effects of partial volume. |
| 3149 | Computer #51 |
Ungated, Free-breathing Native T1 Mapping in Multiple Cardiac Phases in Under One Minute: A Proof of Concept |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States, 3Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States |
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Current cardiac T1 mapping techniques are generally limited to single-shot 2D images acquired in a breath hold with ECG gating. Heart rate variability or poor ECG triggering are sources of error and reduced reproducibility in the widely used MOLLI T1 mapping technique. To mitigate the dependence of T1 mapping on heart rate and breath-holds, we propose an ungated, free-breathing, continuous IR approach using low-rank tensors modeling the image as partially separable in space, cardiac phase, respiratory phase, and inversion time. We show the feasibility of the ungated, free-breathing approach in producing T1 maps in multiple cardiac phases in under 1 minute. |
| 3150 | Computer #52 |
Cardiac Tissue Characterization in End Stage Renal Disease Patients with Non-Contrast MRI and Myocardial Mechanics |
1Department of Physiology, University of Kentucky, Lexington, KY, United States, 2Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, United States, 3College of Medicine, University of Kentucky, Lexington, KY, United States, 4Institute for Advanced Application, Geisinger Health System, Danville, PA, United States, 5Gill Heart Institue, University of Kentucky, Lexington, KY, United States, 6Biomedical Engineering, University of Kentucky, Lexington, KY, United States |
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Patients with end stage renal disease (ESRD) suffer from high rates of sudden cardiac death, often attributed to development of reactive fibrosis. This study aims to integrate cardiac tissue characterization via non-contrast 2-pt bSSFP with myocardial mechanical analysis. ESRD patients demonstrate elevated myocardial signal with magnetization transfer-weighted 2-pt bSSFP, indicating increased fibrosis. This elevated signal correlates with delayed time to peak contraction and septo-lateral dyssynchrony, which are both elevated in ESRD patients. Combining non-contrast 2-pt bSSFP for tissue characterization with analysis of regional contractile function offers a promising approach to identify potential MRI biomarkers of cardiac risk in ESRD. |
| 3151 | Computer #53 |
3D Free Breathing Whole Heart T1 mapping at 3 T |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of |
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In this study, we developed a free-breathing, three-dimensional (3D) T1 mapping method at 3T based on the saturation-prepared, inversion-prepared radiofrequency-spoiled gradient echo (SPGR) sequence, which achieved 3D T1 maps with whole heart coverage. Excellent correlation for the T1 values typically observed in myocardium pre and post contrast was obtained with little residual (R2 = 0.99) and a regression slope 0.93. Homogeneous T1 maps were obtained from in-vivo study. Whole left ventricle T1 mapping was finished in around ~10 minutes with about 40% navigator efficiency without using any parallel imaging. Measured normal myocardium T1 values were comparable to those previously published. |
| 3152 | Computer #54 |
Myocardial T1- and ECV- Mapping at 3 Tesla using the Saturation-Recovery Techniques SASHA and SAPPHIRE |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, 2DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany, 3Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States, 4Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 5Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, 61st Department of Medicine Cardiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany |
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Myocardial T1- and ECV-mapping for the detection of fibrosis is commonly performed at 1.5T with inversion-recovery (IR) techniques such as MOLLI. As an alternative, we studied the robustness and precision of the saturation-recovery (SR) T1-mapping techniques SAPPHIRE and SASHA at 3T in 20 healthy volunteers. The resulting T1- and ECV- reference values for SR T1-mapping were 1578±42ms/0.30±0.03 (SAPPHIRE) and 1523±46ms/0.31±0.03 (SASHA), revealing the underestimation of T1-times by MOLLI to be approximately 20-29%. Therefore, we suggest SR T1-mapping with its high accuracy, low precision-loss, and good inter-subject variability as a valuable alternative to IR T1-mapping at 3T. |
| 3153 | Computer #55 |
Free-breathing SASHA T1 mapping using high-contrast image registration has greater precision than MOLLI T1 mapping |
1Medicine, Division of Cardiology, University of Virginia, Charlottesville, VA, United States, 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States |
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The robustness of SASHA T1 mapping to systematic errors provides more accurate T1 measurements, but SASHA is less precise than the more commonly used MOLLI sequence. Free-breathing SASHA acquisitions can increase precision in T1 maps, but motion correction of SASHA images is challenging due to poor blood-tissue contrast. We present a novel approach for robust image registration by acquiring additional high-contrast data in a keyhole fashion without affecting T1 accuracy. In 10 healthy subjects, a SASHA T1 maps acquired in <90 seconds of free-breathing had a lower myocardial T1 standard deviation than MOLLI (46.1±3.8 ms vs. 55.3±7.7 ms, p<0.05). |
| 3154 | Computer #56 |
Sensitive Non-contrast CMR Index for Quantifying Myocardial Fibrosis |
1Radiology, West Hospital, Chengdu, China, People's Republic of, 2NIH, Bethesda, MD, United States, 3Radiology, Washington University in St. Louis, St. Louis, MO, United States, 4Cardiology, West Hospital, Chengdu, China, People's Republic of |
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The purpose is to develop and evaluate a non-contrast CMR approach for sensitive and quantitative assessment of myocardial fibrosis. Ten patients with cardiomyopathy were scanned with and without contrast injection. A quantitative fibrosis index derived from native T1ρ dispersion contrast was obtained and compared with extracellular volume calculated by T1 mapping. A strong correlation was shown between two indexes and superior sensitivity was observed for fibrosis index to detect myocardial diffuse fibrosis. |
| 3155 | Computer #57 |
Fat Signal Removal in LGE using Phase-Sensitive ChEmical Selection (PiSCES) |
1GE Global Research, Munich, Germany, 2Advanced Cardiovascular Imaging, New York, NY, United States, 3GE Healthcare, Munich, Germany |
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Late Gadolinium Enhancement (LGE) with fat suppression typically leaves traces of fat signal in the image. The goal of the present work is to completely remove fat signal from the LGE image and to visualize fat separately. The PiSCES method applies phase sensitive image reconstruction and customized timing of fat-selective RF pulses. In 19 out of 22 patient examinations PiSCES better removed fat compared to conventional magnitude fat-suppressed LGE. |
| 3156 | Computer #58 |
Automatic extracellular volume fraction mapping in the myocardium: multiple initial T1 values and deformable image registration combined with LV segmentation |
1Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, 2Radiology, Kao-Hsiung Veterans General Hospital, Kao-Hsiung, Taiwan |
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This study attempted to improve the accuracy of T1 fitting and image registration for automatic extracellular volume fraction mapping. We proposed to use multiple initial values in the T1 fitting procedure and the results prominently exhibited less errors. For the image registration, we first performed the automatic segmentation of left-ventricle (LV) walls based on an image synthesis approach and then used the obtained LV masks for the deformable image registration. The results supported that the method significantly improved the overlap rate between the pre- and postcontrast images as well as the accuracies of the obtained ECV maps. |
| 3157 | Computer #59 |
Native myocardial T1 correlates with right ventricular mass and invasive catheter measurement in patients with Pulmonary Hypertension |
1Academic Unit of Radiology, The University of Sheffield, Sheffield, United Kingdom, 2Department of Cardiovascular Imaging, Kings College London, London, United Kingdom, 3The University of Sheffield, Sheffield, United Kingdom, 4University of Cambridge School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom |
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Patients with pulmonary hypertension (n=102, 58±16 years, 56% female) and age and sex matched volunteers (n=34, 51±14 years, 58% female) underwent functional cardiac MR and MOLLI T1 mapping at 1.5T. MOLLI images were registered to correct for respiratory motion. Patients had elevated myocardial T1 at the right ventricular (RV) insertion point (p<0.001) and left ventricular free wall when compared to healthy volunteers (p=0.013). RV insertion point T1 and pulmonary artery pressure correlated significantly (r=0.406 p=0.016). Correlations were found between RV free wall and septal T1 and diastolic mass index (corrected for age and sex) (r=0.305, p=0.003 and r=0.281, p=0.006 respectively). Patients with pulmonary hypertension (n=102, 58±16 years, 56% female) and age and sex matched volunteers (n=34, 51±14 years, 58% female) underwent functional cardiac MR and MOLLI T1 mapping at 1.5T. MOLLI images were registered to correct for respiratory motion. Patients had elevated myocardial T1 at the right ventricular (RV) insertion point (p<0.001) and left ventricular free wall when compared to healthy volunteers (p=0.013). RV insertion point T1 and pulmonary artery pressure correlated significantly (r=0.406 p=0.016). Correlations were found between RV free wall and septal T1 and RV mass index (corrected for age and sex) (r=0.305, p=0.003 and r=0.281, p=0.006 respectively). |
| 3158 | Computer #60 |
Characterization of Compacted Myocardial Abnormalities by Cardiac Magnetic Resonance with Native T1 Mapping in Left Ventricular Non-compaction Patients: A Comparison with Late Gadolinium Enhancement |
1Cardiology, Peking Union Medical College, Beijing, China, People's Republic of, 2Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of |
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Left Ventricular Non-compaction (LVNC) manifesting with myocardial fibrosis can cause cardiac dysfunction, arrhythmia, and sudden death. Native T1 mapping is an emerging CMR technique in quantitative evaluation of myocardial fibrosis. This study aimes to investigate the usefulness of native T1 mapping in characterization of myocardial abnormalities in LVNC patients by comparing with late gadolinium enhancement. It may suggest that native T1 mapping may provide information for early detection of fibrosis in compacted myocardium and stratification of severity in Left Ventricular Non-compaction. |
| 3159 | Computer #61 |
Optimized Acquisition for Joint T2 and ADC mapping in the Heart |
1Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China, People's Republic of, 2Department of Radiological Sciences, University of California, Los Angeles, CA, United States, 3Physics & Biology in Medicine Graduate Program, University of California, Los Angeles, CA, United States |
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Myocardial T2 and Apparent Diffusion Coefficient (ADC) can be used to evaluate the presence of edema and myocardial infarction1,2. We recently developed a technique for joint acquisition and reconstruction of T2 and ADC maps using a spin-echo EPI diffusion weighted sequence (SE-EPI DWI) with a total acquisition time short enough to accommodate measurement in a single breath-hold. The objective of this study was to optimize the joint T2/ADC acquisition to enhance sensitivity to myocardial infarction and to evaluate performance in simulations and phantom experiments. |
| 3160 | Computer #62 |
Myocardial Local Frequency Shift Mapping |
1Imaging Research Laboratories, Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada, 2Department of Research and Education, Saint Francis Hospital, Roslyn, NY, United States, 3Medical Biophysics, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada |
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Local Frequency Shift (LFS) mapping of the myocardium may provide information about the integrity and organization of myofibers, which contribute anisotropic magnetic susceptibility. We present a myocardial LFS mapping method by explicitly removing the unwanted phase terms caused by B0 inhomogeneity and chemical-shift (CS) between fat and water. The proposed method was tested with human data and compared with the established high-pass filtering technique. The results demonstrate a gradient across the myocardial wall suggesting that LFS maps of the myocardium may enable visualization of myofiber orientation. |
| 3161 | Computer #63 |
Myocardial Effective Transverse Relaxation Time at 7.0 T Correlates with Left Ventricular Wall Thickness |
1Berlin Ultrahigh Field Facility (B.U.F.F), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany, 2Institute for Physiology, Charité University Medicine, Berlin, Germany, 3Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, 4Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicince in the Helmholtz Association, Berlin, Germany |
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This work examines the relationship of ventricular septal wall thickness and T2* at 7.0T in healthy volunteers. Results show, that T2* changes periodically over the cardiac cycle, increasing in systole and decreasing in diastole. A strong correlation between mean septal T2* and wall thickness was found. Temporally resolved field mapping showed that macroscopic magnetic field fluctuations can be excluded as source of the observed changes. While T2* is often regarded as surrogate for tissue oxygenation, the found systolic increase of T2* cannot be explained by increased oxygenation. Instead changes in blood volume fraction are assumed to be responsible for the observed T2* fluctuations. |
| 3162 | Computer #64 |
Myocardial Extracellular Volume Measurements using a shorter post-contrast T1 mapping delay time for Diagnosis of Cardiac Amyloidosis in 3.0T Cardiac Magnetic Resonance |
1Peking Union Medical College Hospital, Beijing, China, People's Republic of, 2Siemens Shenzhen Magnetic Resonance Ltd., beijing, China., Beijing, China, People's Republic of, 3MR Research and Development, Siemens Healthcare, Chigago, IL, United States |
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The study aim was to explore the diagnostic value of ECV for cardiac amyloidosis calculated by 5 min post-contrast T1-mapping compared with conventional 15-20 min post-contrast T1 mapping. The results showed ECV calculated by 5min post-contrast T1 mapping had similarly promising diagnosis value for cardiac amyloidosis compared with 15-20 min post-contrast T1 mapping. |
| 3163 | Computer #65 |
Free-breathing 3D myocardial T2 mapping using image-based respiratory motion correction |
1King's College London, London, United Kingdom |
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Image navigator based free-breathing whole heart 3D T2prep-based T2 mapping achieved similar accuracy to a conventional 2D-BH T2prep-based mapping approach, and can be performed within less than 5 minutes. With this approach the limitations of conventional 2D T2 mapping (low resolution, mis-registration and diaphragmatic motion between BH) as well as 3D T2 mapping (unpredictable scan time because of navigator gating) have been overcome. These promising results warrant further investigation in patients with myocardial pathologies. |
| 3164 | Computer #66 |
Rapid T1-Mapping of Mouse Hearts using Real-Time MRI |
1Department of Diagnostical and Interventional Radiology, University of Würzburg, Würzburg, Germany, 2Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 3Institute of Mathematics, University of Würzburg, Würzburg, Germany, 4Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom |
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The feasibility of using real-time MRI to determine $$$T_1$$$ relaxation times in mouse hearts was explored. An inversion recovery prepared and highly undersampled radial acquisition was applied and data were reconstructed using a combination of through-time radial GRAPPA and compressed sensing. The ECG in combination with the DC-signal recorded for each projection was used to eliminate cardiac and respiratory motion, which allowed for fitting $$$T_1$$$-values in every voxel. The method was applied to five mice in vivo and the measured $$$T_1$$$-values found for myocardial tissue agreed well with literature. Our work indicates that it is possible to accurately measure $$$T_1$$$ in mice using real-time MRI. |
| 3165 | Computer #67 |
3D T1-weighted self-gated cardiac MRI for assessing myocardial infarction in mouse models |
1University of Science and Technology of China, Hefei, China, People's Republic of, 2Shenzhen Institutes of Advanced Technology, Shenzhen, China, People's Republic of, 3Cedars-Sinai Medical Center, Los Angeles, CA, United States |
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A 3D self-gating technique was developed for assessing mycardial infarction (MI) in mouse model. The preliminary in vivo study has demonstrated that the technique can correctly detect the MI, which may outperform the conventional MR techniques with ECG-triggering and respiratory gating. |
| 3166 | Computer #68 |
Cardiac Magnetic Resonance T1 mapping in pulmonary hypertension. Is Native T1 mapping an alternative to Late Gadolinium Enhancement? |
1Scottish Pulmonary Vascular Unit, Golden Jubilee National Hospital, Glasgow, United Kingdom, 2Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom |
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Pulmonary hypertension is a rare progressive disorder characterised by elevated pulmonary artery pressure leading to right ventricular failure and death. Native T1 mapping is a CMR technique for myocardial tissue characterisation that does not require MRI contrast administration1. We investigated whether native T1 values relate to invasive pressure measurements and markers of RV dysfunction in patients with pulmonary hypertension. |
| 3167 | Computer #69 |
High resolution Magnetic Resonance Imaging (MRI) combined with Magnetization Transfer (MT) for the visualization of the cardiac structure: an ex vivo proof of concept |
1IHU LIRYC, Université de Bordeaux, Pessac, France |
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The motivation of this study was to investigate Magnetization Transfer MRI as a technique of contrast for visualization of the Purkinje Fiber (PF) network in ex vivo cardiac sample of a large animal. We first optimized MT parameters to obtain the best contrast: offset frequency, duration of the module and radiofrequency field. We performed 2D and 3D acquisition on pig ex vivo heart. We were able to enhance contrast between PF network and muscle and visualize insert points inside the myocardium in 3D.
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| 3168 | Computer #70 |
Self-navigated cardiac T1 mapping using an ultra short echo time (UTE) inversion recovery acquisition |
1Experimental Physics 5, University of Wuerzburg, Wuerzburg, Germany, 2Medizinische Klinik und Poliklinik I des Universitaetsklinikums Wuerzburg, Wuerzburg, Germany |
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Radial trajectories enable self-navigated cardiac T1 measurements without the necessity of external ECG signals. However, the extracted cardiac synchronization signals and the reconstructed images can be suspectible to B0 inhomogeneities and flow. In order to improve the robustness of the self-navigated method a 2D - UTE inversion recovery sequence is introduced that minimizes the echo time to 0.57 ms and reduces the susceptibility to B0 inhomogeneities. Steady state cines and a T1 map were derived from the UTE measurement. Comparisons with a self-navigated gradient echo measurement indicate more reliable self-navigation signals and better image quality when using shorter echo times. |
| 3169 | Computer #71 |
Wideband Adiabatic Inversion with a Hyperbolic Secant 4 (HS4) Pulse for Late Gadolinium Enhancement MRI of Patients with Implanted Cardiac Devices |
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 2Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, Los Angeles, CA, United States |
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We present a wideband inversion pulse of 8kHz bandwidth designed with a hyperbolic secant 4 (HS4) adiabatic inversion pulse, for use in wideband late gadolinium enhancement (LGE) MRI in patients with implantable cardioverter-defibrillators (ICDs). This HS4 wideband pulse has more than twice the bandwidth of the previously reported wideband hyperbolic secant (HS) adiabatic inversion pulse for wideband LGE. We demonstrate that the wideband HS4 pulse is superior to the wideband HS pulse in eliminating hyperintensity artifacts resulting from off-resonance induced by an ICD in the myocardium. |
| 3170 | Computer #72 |
Myocardial T1-map-derived extracellular volume fraction (ECV) measurement can represent the disease severity and prognostic information in patients with dilated cardiomyopathy (DCM) |
1Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 2Division of Cardiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan |
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Myocardial fibrosis is closely related to clinically evident cardiac dysfunction and worse outcomes, such as heart failure and arrhythmia. Therefore, non-invasive methods, which can reliably quantify fibrosis, would be preferable. In this study, we demonstrated that T1-map-derived ECV measurement is a significant independent predictor of major adverse cardiovascular events (MACEs) when compared with the presence of LGE and other risk factors. ECV may thus represent a novel prognostic indicator in patients with DCM. |
| Exhibition Hall | Tuesday, May 10, 2016: 10:00 - 11:00 |
| 3171 | Computer #1 |
Accelerated Multi Echo based Correlated spectroscopic imaging of calf muscle in three spatial dimensions |
1Radiological Sciences, UCLA School of Medicine, Los angeles, Los Angeles, CA, United States |
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Multi-echo based echo-planar correlated spectroscopic imaging (ME-EP-COSI) has been an innovative method to study muscle lipid content in T2D and a variety of other metabolic conditions. In this study we implemented accelerated ME-EP-COSI and validated in a corn oil phantom and in healthy human calf muscle. Both phantom and human calf muscle results show that 5D ME-EP-COSI has the potential to be a powerful tool for human calf muscle examination. Further studies will investigate various pathologies, including obesity and type 2 diabetes, using the 5D ME-EP-COSI method. |
| 3172 | Computer #2 |
Frequency Shift Imaging (FSI) for characterization of cells labeled with superparamagnetic iron-oxide nanoparticles |
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Department of Biomedical Engineering, City College of New York, New York, NY, United States |
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MRI has long been used as a detection tool for cells labeled with superparamagnetic iron-oxide nanoparticles (SPIOs). Positive contrast imaging of off-resonance SPIO signal provides benefits over negative contrast methods and imaging the SPIOs at 7 Tesla (7T) allows for leveraging greater off-resonance sensitivity for quantitative imaging of smaller cell populations. In this study, we imaged a cell phantom containing SPIO labeled macrophages at 7T. We demonstrated the performance of frequency shift imaging (FSI), a new acquisition technique, for characterizing the magnetic signature of SPIOs, as compared to negative contrast methods. |
| 3173 | Computer #3 |
Trajectory design of optimized repeating linear and nonlinear gradient encoding using a k-space point spread function metric |
1Biomedical Engineering, Yale University, New Haven, CT, United States, 2Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States |
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Accelerated imaging with nonlinear gradients can result in undersampling artifacts. A computationally efficient k-space point spread function metric that reflects the qualitative features of interest in the object is used to design a repeating nonlinear gradient trajectory that can be added to the linear trajectory. The nonlinear gradient solution is found through optimization of the metric calculated for only a few time points in the linear trajectory over a subregion of k-space containing the linear encoding. Images reconstructed from data simulated with the optimized nonlinear trajectories result in less undersampling artifacts compared to linear trajectories. |
| 3174 | Computer #4 |
COBRA - Continuously Ordered B0 Readout Acquisition |
1Immunity, Infection and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom, 2Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom |
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A novel encoding method known as Continuously Ordered B0 Readout acquisition or COBRA is described. The method uses an additional B0 coil with a unique field at every point in space to perform Volume Frequency Encoding. The field increases as a monotonic function within the coil and can be sorted to the appropriate 3D location for reconstruction. 3D data sets have been acquired and reconstructed at 9.4T. |
| 3175 | Computer #5 |
Application of Spin Echoes in the Regime of Weak Dephasing to Oxygen Enhanced T1-Quantification in the Lung |
1Dept. of Radiology - Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2Dept. of Chemistry, Technische Universität München, Munich, Germany |
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This paper proposes an inversion-recovery spin-echo SNAPSHOT-FLASH sequence for quantifying proton-density and T1 of the lung. It is shown that T1 is reduced compared to the standard gradient-echo sequence. Similar results have been previously reported for UTE sequences. In combination with an iterative algorithm that is similar to MR-fingerprinting reconstructions, the feasibility of acquiring quantitative maps of the entire lung with a resolution of 5 mm x 5 mm x 10 mm within 5.5 s is demonstrated. |
| 3176 | Computer #6 |
Single Point Imaging with Broadband Excitations and Ultra-Short Echo Times for Imaging near Metallic Implants |
1Radiology, University of Wisconsin, Madison, WI, United States, 2Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN, United States, 3Biophysics and Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 4Medical Physics, University of Wisconsin, Madison, WI, United States, 5Biomedical Engineering, University of Wisconsin, Madison, WI, United States, 6Medicine, University of Wisconsin, Madison, WI, United States, 7Emergency Medicine, University of Wisconsin, Madison, WI, United States |
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Large magnetic susceptibility differences between metallic implants and tissue generate severe B0 inhomogeneities that present several challenges for MR: excitation of the entire off-resonance spectrum, distortion in the frequency encoding direction, and severe intra-voxel dephasing. In this work we propose an ultra-short echo time acquisition with broadband excitation. Single point encoding was use to avoid in-plane distortions while 3D undersampling facilitated clinically feasible acquisition times. The effects of RF pulse duration on signal loss near the implant and T1 weighting were evaluated in a total hip replacement phantom and a volunteer with a total knee replacement. |
| 3177 | Computer #7 |
Artery selective 3D TOF by Using Asymmetrically RF-shimmed Pre-saturation pulse with 4-channel RF Transmit at 3T |
1Healthcare Company, Hitachi Ltd., Chiba, Japan, 2Research and Development Group, Hitachi Ltd., Tokyo, Japan |
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A technique of ICA-selective 3D TOF imaging using asymmetrically RF-shimmed Pre-saturation pulse is presented. By using 4-channel RF transmit coil, spatially asymmetric RF transmission is achieved. Then apply RF shimming parameter to Pre-saturation pulse, the saturation effect becomes spatially asymmetric, and achieved selectively visualize blood flow from each ICA. This technique provides high contrast between blood and brain parenchyma because it does not make TR longer. |
| 3178 | Computer #8 |
Spectrally selective 3D dynamic bSSFP for hyperpolarized C-13 metabolic imaging at 14.1T |
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, 2Bioengineering, UC Berkeley - UCSF, San Francisco / Berkeley, CA, United States, 3Electrical Engineering, Stanford University, Stanford, CA, United States, 4HeartVista, Menlo Park, CA, United States |
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Balanced SSFP sequences can provide superior SNR efficiency for hyperpolarized 13C imaging, by efficiently utilizing the non-recoverable magnetization. A spectrally selective bSSFP sequence was developed to enable fast mapping of hyperpolarized metabolites. A novel approach for bSSFP spectral selectivity was developed utilizing a combination of optimized multiband RF pulses and a bSSFP pulse train with a carefully chosen TR to avoid banding artifact. The sequence enabled 3D dynamic imaging of HP resonances generated in studies with co-polarized pyruvate and urea (with ~1% selectivity), attaining 2mm isotropic resolution and <1s temporal resolution. |
| 3179 | Computer #9 |
Interleaving SSFP Signal Acquisition |
1Paul C. Lauterbur Research laboratory for Biomedical imaging, Shenzhen Institutes of Advanced Technology, ShenZhen, China, People's Republic of |
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We propose to acquire the different components in the steady state signal by interleaving. Using DESS as an example, we show that through appropriate gradient design, the two major components (S+ and S-) in the SSFP signal can be separately acquired in alternate TR and form images similar to those conventionally acquired by DESS. The new technique shortens TR and reduces motion and diffusion sensitivity. |
| 3180 | Computer #10 |
Fast 3D Magnetic Resonance Fingerprinting (MRF) For Whole Brain Coverage in Less Than 3 Minutes |
1Radiology, Case Western Reserve University, Cleveland, OH, United States, 2Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States |
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The purpose of this study is to accelerate the acquisition time of 3D MRF scans. A simple acquisition scheme was applied to allow a total factor of 144 acceleration as compared to the Nyquist rate, such that 3D T1, T2 and proton density maps can be acquired from a whole brain scan at clinical resolution in 2.6 minutes. |
| 3181 | Computer #11 |
A Multishot, Hadamard-Encoded Autocalibration Scan for Multiband EPI at 7T |
1Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 2Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States |
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A multiband (MB) echo planar imaging (EPI) sequence with multishot autocalibration was developed and implemented at 7T. Slices were unaliased using the principles of Hadamard encoding, resulting in a fully-sampled calibration scan reconstructed without parallel imaging techniques. A Hadamard unaliasing procedure was demonstrated with an acceleration factor of lower rank than the Hadamard encoding matrix. Using this sequence, a functional MRI protocol at 7T was introduced to obtain a sufficient calibration volume, that was then utilized to unalias the remaining repetitions using a slice-GRAPPA technique. Preliminary resting state data acquired using this protocol has generated reliable connectivity networks. |
| 3182 | Computer #12 |
3D Metabolite and Neurotransmitter Mapping Using Multiple-TE Encoding with Sparse Sampling |
1Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 2Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States |
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We present an integrative subspace-based sampling and reconstruction method for 3D high-resolution mapping of brain metabolites and neurotransmitters using MRSI. An echo-planar spectroscopic imaging sequence with J-resolved encoding capability has been developed to implement the proposed sparse sampling strategy for fast spatiospectral encoding. An explicit subspace model-based reconstruction scheme that incorporates J-resolved spectral prior to enable joint reconstruction of the metabolite and neurotransmitter signal components from the sparse data is described. Results from experimental data are used to demonstrate the capability of the proposed method in producing high-resolution and high-SNR spatiospectral distributions of both metabolites and neurotransmitters. |
| 3183 | Computer #13 |
Three Minute Whole-heart Magnetic Resonance Angiography with Prospective Heart Tracking and Compressed Sensing Parallel Image Reconstruction |
1Pediatrics, Harvard Medical School, Boston, MA, United States, 2Cardiology, Boston Children's Hospital, Boston, MA, United States, 3German Center for Cardiovascular Research (DZHK), Goettingen, Germany, 4Department of Diagnostic and Interventional Radiology, University Medical Center, Goettingen, Germany, 5Division of Imaging Sciences and Biomedical Engineering, King’s Health Partners, St. Thomas’ Hospital, King’s College London, London, United Kingdom |
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To accelerate whole-heart magnetic resonance angiography, we implemented a variable density Poisson disc undersampling pattern and compressed sensing parallel image reconstruction, and compared it to a standard parallel image (SENSE) acquisition in 15 patients. The compressed sensing technique was faster (mean 3.4±1.0 minutes vs 7.6±1.7 minutes) and had similar objectively measured sharpness in 4 designated regions (all p>0.05) but a lower subjective image quality scores (all p≤0.05). |
| 3184 | Computer #14 |
MR relaxometry with an interleaved SSFP sequence |
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, CAS, Shenzhen, China, People's Republic of |
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A novel SSFP sequence with interleaved acquisition for F0, F- and F+ was proposed and applied to T1/T2 relaxometry. The good agreement with analytical solution of SSFP implies that steady state is maintained at different TR. Compared to TESS, TEs of the three echoes can be identical to eliminate T2* effect. The reduced TR decreases susceptibility induced signal void and motion sensitivity. The crusher in slice select direction avoids the unwanted diffusion effect for high resolution imaging. The phantom study shows that the T1/T2 relaxometry results are consistent with the traditional IR-TSE and SE results. |
| 3185 | Computer #15 |
Feasibility of Abdominal k-t GRAPPA Accelerated Dual-Venc 4D flow MRI in the Setting of Portal Hypertension |
1Radiology, Northwestern University, Chicago, IL, United States, 2Biomedical Engineering, Northwestern University, Evanston, IL, United States |
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Abdominal 4D flow MRI is currently limited by long acquisition times required to capture the wide range of velocities and flows present in the abdomen with separate low and high velocity encoding gradient (venc) acquisitions. By instead using a single 4D flow sequence with two different velocity encodings (dual-venc), we were able to quantify abdominal hemodynamics with similar accuracy in a total of 21% less time. Overall, this is encouraging as it directly addresses scan time, a major limitation of 4D flow MRI, increasing its clinical utility. |
| 3186 | Computer #16 |
Gradient Optimization for arbitrary k-space trajectories using Active Contour (GO-Active) |
1Medical Imaging Research Centre, Dayananda Sagar College of Engineering, Bangalore, India, 2Bangalore, India, 3Wipro-GE Healthcare, Bangalore, India |
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K-space trajectories such as cartesian, radial, spiral are not optimal for traversing arbitrary k-space shapes. GO-Active is a novel acquisition technique which is a combination of active contour and convex optimization where active contour was used to obtain arbitrary k-space trajectory and convex optimization was employed to optimize the gradients based on hardware constraints. Reconstruction was performed using Non Uniform Fast Fourier Transform and compressed sensing. Retrospective study was performed on six brain datasets and phantom, where as prospective study was carried out on the phantom respectively. Current and Future work involves application of GO-Active on in vivo data prospectively. |
| 3187 | Computer #17 |
Beachball: A fast and efficient 3D k-space trajectory with time optimal gradients |
1Medical Imaging Research Centre, Dayananda Sagar College of Engineering, Bangalore, India |
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3D Variable density spiral (VDS)–“beachball” was designed and generated to cover 3D k-space efficiently. Beachball is obtained by rotating along one axis of a 2D VDS for various number of shots. Beachball was demonstrated in-silico by analyzing point spread function and restrospective analysis of a in-vitro water phantom. Reconstruction was done using NUFFT. Optimal gradient waveforms were generated for beachball by using convex optimization formulations based on the constraints of maximum gradient amplitude and slew rate. This trajectory provides for smoother coverage and densely sampled at the centre of k-space and allows implementation of silent MR. |
| 3188 | Computer #18 |
Design of a k-space trajectory allowing the reconstruction of both standard and accelerated data in fat-suppressed DCE-MRI of breast |
1Imagerie Adaptative Diagnostique et Interventionnelle, Université de Lorraine, Nancy, France, 2U947, INSERM, Nancy, France, 3CIC-IT 1433, INSERM, Nancy, France |
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DCE-MRI protocol is the reference technique to detect and characterize breast lesions. Due to the high spatial resolution needed to detect small lesions, the temporal resolution of the DCE-MRI protocol is limited to 90 seconds. A good fat suppression is also needed and a spectral inversion preparation is commonly used for it. To provide more information about lesion vascularization, temporal resolution need to be increased. We have developed a method to implement a smart k-space trajectory allowing both standard DCE-MRI protocol reconstruction and accelerated DCE-MRI protocol via Compressed-Sensing reconstruction compatible with fat suppression. |
| 3189 | Computer #19 |
Dual Echo Trajectory for Novel Fast Acquisition |
1Laboratory for Imaging Science and Technology, Department of Electrical and Computer Engineering, Seoul national university, Seoul, Korea, Republic of |
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In this study, we propose a new fast acquisition trajectory, Dual Echo Trajectory (DuET), to accelerate spin echo imaging. The proposed method allowed a 2-fold increase in acquisition speed with minimum image artifacts. |
| 3190 | Computer #20 |
Composite pulses for RF phase encoded MRI |
1Biomedical Engineering, University of Saskatchewan, Saskatoon, SK, Canada, 2Medical Imaging, University of Saskatchewan, Saskatoon, SK, Canada |
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RF phase encoded MRI uses spatial RF phase gradients in place of B0 gradients coils to encode information. Using a nonlinear RF phase gradient coil instead of linear one leads to a larger field of view. However, this coil will generate an in-homogeneous B1 field which result in pulse imperfection. To minimize the effect of pulse imperfection, the application of composite pulses is required. Current composite pulses were designed to use in current MRIs (having gradient coils and uniform RF coil), so the feasibility of working composite pulses with an RF encoded coil needs to be checked. |
| 3191 | Computer #21 |
B1-sensitive Encoding for Magnetic Resonance Fingerprinting |
1Siemens Healthcare GmbH, Erlangen, Germany, 2Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States |
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Quantitative parameter maps obtained from Magnetic Resonance Fingerprinting (MRF) are sensitive to B1+ inhomogeneities. In principle, one could reduce this dependency by using a dictionary with an additional B1+ dimension. However, if the dictionary entries are not well distinguishable, the simultaneous pattern matching of three parameters (T1, T2, B1+) will not work reliably. In order to improve the separation of data in the B1+ dimension, we implemented a novel B1+ sensitive encoding. This approach employs a dedicated composite RF excitation pulse which directly encodes B1+ magnitude information into the phase of the acquired signal. Here we present an experimental proof of principle using a 1D projection MRF sequence. |
| 3192 | Computer #22 |
Selective Hepatic Artery Imaging Using Beam IR pulse |
1Healthcare Company, Hitachi, Ltd., Chiba, Japan |
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We confirmed that 2D beam excitation presaturation-pulse (hereafter Beam Sat pulse) can saturate the vessels selectively and visualized hemodynamics in brain and liver. Although Beam Sat can visualize portal vein and hepatic artery, right hepatic artery (RHA) cannot visualize clearly because T1 relaxation of saturated blood magnetizations is short. In this study, 2D excitation pulse was used as IR pulse (hereafter Beam IR pulse), and we showed that the Beam IR pulse can clearly visualize a flow phantom and RHA of healthy volunteers. |
| 3193 | Computer #23 |
Accelerated imaging of sub-volumes using region-of-interest focused O-Space: Experimental verification of rOi-Space |
1Diagnostic Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States, 2Neurosurgery, Yale University, New Haven, CT, United States |
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rOi-Space is a region-of-interest imaging technique. The method uses a nonlinear gradient field for improved accelerated imaging similar to O-Space but focuses the encoding effort to the region-of-interest rather than imaging the whole field-of-view. Simulations showed improved reconstruction compared to radial acquisitions for acceleration factors between 2.2 and 14.2 and up to 70% reduction in reconstruction error, for acceleration factors of around 4. Noise performance comparisons demonstrate some degraded SNR performance due to intra-voxel dephasing. Experiments showed improved resolution inside the ROI at the expense of SNR performance. Hence, the method can be used for resolution enhancement in applications with adequate SNR. |
| Exhibition Hall | Tuesday, May 10, 2016: 10:00 - 11:00 |
| 3194 | Computer #25 |
Teaching MRI using Tuning Forks and Speakers |
1College of Science (Physics), Swansea University, Swansea, United Kingdom, 2Medical Imaging, Swansea University, Swansea, United Kingdom |
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We illustrate some key basic concepts in MRI such as resonance, frequency-based slice selection and readout, as well as relaxation using tuning forks and sound waves. |
| 3195 | Computer #26 |
EPGspace: A Flexible Framework for Extended Phase Graphs of Periodic and Non-Periodic MRI Sequences |
1Dept. of Radiology, Radiological Physics, University of Basel Hospital, Basel, Switzerland |
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The Extended Phase Graph (EPG) calculus can be understood as a solution of the Bloch equation using its k‑space representation. The ability to represent magnetization in phase state configurations frequently enables an intuitive and pictorial understanding of echo formation and assignment. A class of functions that allows for the easy calculation and simulation of EPGs for arbitrary MR sequences was developed (EPGspace) and its key points are presented. The EPGspace source code is made publically available for download in the internet. |
| 3196 | Computer #27 |
Equivalence of EPG and Isochromat-based simulation of MR signals |
1Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom, 2Imaging Division, University Medical Centre, Utrecht, Utrecht, Netherlands |
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Extended Phase Graphs and Isochromat-summation are two leading methods for simulating MR signals. The latter method is more intuitive, but choice of the number and distribution of isochromats significantly affects results. It is well known that the two methods are related by Fourier Transform, but precise equivalence is not widely understood. We demonstrate conditions under which they are exactly equivalent and related by DFT. Choice of isochromats is shown to be a sampling problem and conditions for accurate isochromat-based simulations are given. Matlab code is provided as a direct illustration. |
| 3197 | Computer #28 |
PolyFT: a Freely-Available Optimized MATLAB Implementation of the Polyhedral Fourier Transform for Analytical Simulations in MRI |
1Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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Analytical Fourier transforms (FT), such as FT of 2D and 3D Shepp-Logan phantoms, enable accurate arbitrary k-space sampling of digital phantoms. Here, we present and demonstrate a computationally efficient MATLAB implementation of the analytical FT of polyhedral phantoms with uniform intensity or non-uniform intensities. The computation time of the implementation is presented, as well as demonstrations showing its feasibility of simulating physiologically relevant phantoms and evaluating non-Cartesian sampling trajectories and parallel imaging algorithms. The implementation is now available through the Mathworks user community and GitHub. |
| 3198 | Computer #29 |
Parameter Dependency in Modular MR Sequences using Directed Graphs |
1Fraunhofer MEVIS, Bremen, Germany, 2University of Bremen, Bremen, Germany |
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The interactions of MRI sequence components within complex techniques are hard to explain, grasp and extend using common modularity approaches. This results in poor developability and calculation efficiency. The proposed algorithm yields a new sequence description approach that resolves the component parameter dependencies and enables the calculation of arbitrary module parameters using the least amount of calculation steps. The algorithm has been used on a twice-refocused, spin-echo diffusion MRI sequence to simplify its description and boost the calculation of critical parameters during sequence preparation calculation. |
| 3199 | Computer #30 |
Fast Realistic MRI Simulations Based on Generalized Exchange Spin Model |
1Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States |
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Numerical simulation dramatically improves the understanding and development of new MR imaging methods. We proposed an improved version of MR simulation package named as MRiLab with the feature of incorporating a generalized exchange tissue model to facilitate flexible and realistic MR signal simulation for complex tissue structures. |
| 3200 | Computer #31 |
Using Cellular Automata to Represent MRI Signal Progression |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States |
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In this document we show that we can represent MRI signal progression as a sum of Cellular Automata processes. |
| 3201 | Computer #32 |
Convolutional Forward Modeling for Actual Slice Profile Estimation |
1Medical Imaging Technologies, Siemens Healthcare, Princeton, NJ, United States, 2Siemens Healthcare, Erlangen, Germany, 3Siemens Corporate Technology, Princeton, NJ, United States |
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Resolving slice thickness for better MR reconstruction is desirable, where actual slice profile plays a crucial role. Conventional blind deconvolution formulation includes both original signals and slice profile as unknowns, which is an ill-posed problem with high complexity. We propose a convolutional forward model (CFM), leveraging additional orthogonal stack(s) with an added convolution process in the formulation to fit actual forward imaging process accurately, resulting in a significantly simplified slice profile estimation problem. The actual slice profile is calculated through a data-driven approach. Experimental results demonstrate that the proposed method is robust to handle various challenges. |
| 3202 | Computer #33 |
GPU optimized fast 3D MRI simulator |
1MRTechnology Inc., Tsukuba, Japan, 2University of Tsukuba, Tsukuba, Japan |
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We have developed a GPU optimized fast 3D MRI simulator for pulse sequence developments. We compared simulation and experimental results for gradient echo images of water phantoms that contains an air-filled cylinder and air-filled sphere. The agreements between simulation and experiments were good if the calculation matrix was more than two times that of original images. Because the processing speed of our simulator varied from 2.2 to 3.1 TFLOPS, we concluded that our simulator is useful for development of MRI pulse sequences. |
| 3203 | Computer #34 |
Geometric solution to the fully balanced SSFP signals |
1Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States |
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Fully-balanced steady-state free precession (bSSFP) is clinically useful because of its high SNR efficiency, imaging speed and unique T2/T1 contrast. A geometric solution to bSSFP has been derived and provides a simple and intuitive understanding of how the complex steady-state signals are formed. However, T1 and T2 relaxation has generally been ignored. In this work, we present an exact geometric solution to the bSSFP signals by including the T1 and T2 relaxation effects. The results are consistent with those based on matrix calculations, and are useful in understanding different aspects of bSSFP signal behavior. |
| 3204 | Computer #35 |
Using numerical simulations to compare and evaluate different mathematical models for analyzing dynamic contrast enhanced MRI data |
1Sino-Dutch Biomedical and Information Engineering School, Northeastern University, Shenyang, China, People's Republic of, 2Radiology, University of Chicago, Chicago, IL, United States, 3Electrical and Computer Engineering, University of Texas at El Paso, El Paso, TX, United States, 4Key Laboratory of Medical Image Computing, Ministry of Education, Shenyang, China, People's Republic of |
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Numerical simulations were performed to study analytical mathematical models for fitting tissue contrast agent concentration curves obtained from DCE-MRI. Randomly generated Ktrans and ve were used to calculate the curves using the Tofts model. A total of five analytical mathematical models, empirical mathematical model, modified logistic model, modified sigmoidal function, Weibull model, and extended phenomenological universalities were compared and evaluated in terms of how well they fitted to 100 curves. Statistical analysis showed that the empirical mathematical model provided the best fit out of those models. The analytical mathematical models were different despite having the same number of parameters. |
| 3205 | Computer #36 |
Quantitative Magnetization Transfer Imaging Made Easy with qMTLab: Software for Data Simulation, Analysis and Visualisation |
1Medical Physics, University of Montreal, Montreal, QC, Canada, 2NeuroRX, Montreal, QC, Canada, 3McGill University, Montreal, QC, Canada, 4University of Toronto, Toronto, ON, Canada, 5University of Calgary, Calgary, AB, Canada, 6Ecole Polytechnique, Montreal, QC, Canada |
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We have developed a free, open source software (qMTLab) that unifies the most widely used quantitative magnetization transfer imaging (qMTI) methods in a simple and easy to use graphical interface. qMTLab allows to easily simulate qMTI data, compare the performance of the methods under various experimental conditions, define new acquisition protocols, fit acquired data, and visualize the fitted parameter maps. In this presentation, we will offer a brief introduction on the theory behind qMTI, present the current acquisition and analytical methods, and present the functionality of the qMTLab software and its utility in basic and clinical research. |
| 3206 | Computer #37 |
Modelling intra-voxel dephasing in MR simulations |
1Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2German Cancer Consortium (DKTK), Heidelberg, Germany, 3German Cancer Research Center (DKFZ), Heidelberg, Germany, 4MaRVis Medical GmbH, Hannover, Germany |
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In order to capture intra-voxel dephasing in simulations, the object has to be modeled with a very large number of spins per voxel. We present a method to improve and speed up simulations by explicitly modelling intra-voxel dephasing. The method is evaluated by simulating an MR-safe guidewire. The iron particles in the wire create dipole fields, which lead to dephasing in the proximity of the wire. We show that a substantial reduction of the required number of spins by a factor of ~5.4 is possible, without sacrificing image quality. This reduces the memory requirements and speeds up simulations. |
| 3207 | Computer #38 |
Platform-independent, rapid prototyping of MR sequences without code compilation |
1Fraunhofer MEVIS, Bremen, Germany, 2University of Bremen, Bremen, Germany, 3mediri GmbH, Heidelberg, Germany |
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A platform-independent rapid clinical prototyping environment for MR sequences is demonstrated. Fully interactive product-like sequences can be defined without coding or compiling software. They are saved as plain text files and run by a generic pre-installed software module at the scanner that never needs modifications by a user. Sub-groups of sequence elements can be exported as macros and reused in other sequences. |
| 3208 | Computer #39 |
Real-time speech MRI: what is the optimal temporal resolution for clinical velopharyngeal closure assessment? |
1Clinical Physics Department, Barts Health NHS Trust, London, United Kingdom, 2Imaging Sciences & Biomedical Engineering Research Division, King's College London, London, United Kingdom, 3William Harvey Research Institute, Queen Mary University of London, London, United Kingdom, 4Medical Physics Department, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom |
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Clinical velopharyngeal closure assessment involves imaging patients while they perform standard speech tasks. Real-time MRI could offer an alternative to the imaging techniques used at present, however, there is currently no consensus on the optimal temporal resolution. The purpose of this study is to determine an optimal temporal resolution by comparing the numbers of velopharyngeal closures in high temporal resolution and simulated lower temporal resolution datasets of healthy adult volunteers. The results of this study suggest that the optimal temporal resolution is between 7.5 and 10 frames per second. Future work will aim to pinpoint and validate this resolution. |
| 3209 | Computer #40 |
Real-time MRI of Speech at Very High Temporal Resolution |
1Biomedizinische NMR Forschungs GmbH, Max-Planck-Institute for Biophysical Chemistry, Goettingen, Germany, 2DZHK, German Center for Cardiovascular Research, Goettingen, Germany |
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MRI has become the preferred technique to study the dynamics of tongue and vocal tract during speech, singing or instrument playing. Recent advances provide access to qualitative information of fast tongue movements at very high temporal resolution. In this study, real-time MRI using highly undersampled radial FLASH with regularized nonlinear inverse reconstruction was used to monitor the dynamics of the tongue at 10 ms, 18 ms and 33 ms resolution. The effect of different temporal resolutions on the tongue and oral cavity during speech will be compared and analyzed. |
| 3210
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Computer #41 |
Ultrafast volumetric cine MRI (VC-MRI) for real-time 3D target localization in radiation therapy |
1Department of Radiation Oncology, Duke University, Durham, NC, United States, 2Medical Physics Graduate Program, Duke University, Durham, NC, United States |
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A novel technique has been developed to generate ultra-fast high-quality volumetric cine MRI (VC-MRI) using patient prior information. The VC-MRI was generated by deforming the prior volumetric MRI images based on ultra-fast on-board 2D-cine MRI and patient PCA-based respiratory breathing model. The ultra-fast 2D-cine images were acquired by sampling about 10% of k-space. The undersampled cine images were reconstructed using an iterative MR reconstruction algorithm with a total generalized variation penalty. The technique was evaluated using both anthropomorphic digital phantom and patient data. Results demonstrated the feasibility of generating ultrafast-VC-MRI for both inter-and intra-fraction verification of moving targets in radiotherapy. |
| 3211 | Computer #42 |
Intracranial Dual-Venc 4D flow MRI at 7T: Effect of low versus high spatial resolution in combination with k-t GRAPPA acceleration |
1Radiology, Northwestern University, Chicago, IL, United States, 2Center for Magnetic Resonance in Research, University of Minnesota, Minneapolis, MN, United States, 3Neurosurgery Department, University of Minnesota, Minneapolis, MN, United States |
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Dual-venc 4D flow MRI was applied in 6 healthy volunteers at a 7T MRI scanner at two different approximately isotropic spatial image resolutions, low resolution with (1.1mm)3 and high resolution with (0.8mm)3 voxel volumes. The aim of this study was to systematically investigate the potential of high-resolution k-t GRAPPA accelerated dual-venc 4D flow MRI compared to the low-resolution scan with standard GRAPPA with respect to improved image quality (vessel sharpness and depiction of small intracranial vessels) and quantification of intracranial flow parameters (net flow, peak velocity). |
| 3212 | Computer #43 |
Unsupervised motion correction for real-time free-breathing flow acquisitions: high SNR, single heart-beat, pseudo-breathheld flow images easy to quantify |
1MR R&D, Siemens Healthcare USA, Inc., Chicago, IL, United States, 2MR R&D, Siemens Healthcare USA, Inc., Columbus, OH, United States |
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Flow quantification on uncooperative patients that cannot hold their breath may be performed by real-time free-breathing flow acquisitions that generally cover multiple heart-beats. However, heart-rate fluctuations, low SNR, and respiratory motion associated with such acquisitions may impede flow quantification process. In this study, we are extending our unsupervised motion correction method for real-time free-breathing cine imaging to flow imaging, and comparing the results with gold standard ECG gated, breath-held, segmented flow acquisition. Preliminary results indicate net forward volumes in agreement with the reference, with comparable image quality. |
| 3213 | Computer #44 |
Improved Assessment of Left Ventricular Diastolic Function using High-Temporal Cine-CMR |
1Medicine, The University of Chicago, Chicago, IL, United States, 2Radiology, The University of Chicago, Chicago, IL, United States, 3Philips Healthcare, Cleveland, OH, United States, 4Biomedical Engineering and Radiology, Cornell University, New York, NY, United States |
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Assessment of diastolic function using cine-CMR is limited by its temporal resolution. A high-temporal cine-CMR approach that yields comparable temporal resolution to echocardiography was recently developed using radial trajectories with a custom spoke ordering that exploits the property of prime numbers (Modulo-Prime Spokes, or MoPS), as well as a radial UNFOLD-type streaking artifact removal step. In this study, we validate the functional cine-assessment parameters associated with systolic and diastolic performance of the left ventricle (LV) by comparing the measurements derived from time-volume curves between the proposed radial MoPS-Cine and the clinically employed Cartesian Cine reference. |
| 3214 | Computer #45 |
Breath-Held Phase-Cycled Cardiac Cine MRI using Slow Frequency Modulation |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2HeartVista, Inc., Menlo Park, CA, United States |
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bSSFP is commonly used for cardiac cine imaging due to its high myocardium-blood contrast but suffers from signal nulls due to off-resonance. By modifying the slow frequency modulation scheme for use in the heart, we acquire interleaved phase-cycles within a breath-hold for banding artifact reduction. Because a constant heart rate cannot be assumed, the phase increment increases slowly for a time equal to the shortest expected RR interval and then remains constant until the next trigger. In vivo results indicate that the proposed method is comparable to standard phase-cycling but with shorter scan time and interleaved phase-cycle acquisition. |
| Exhibition Hall | Tuesday, May 10, 2016: 10:00 - 11:00 |
| 3215 | Computer #49 |
Shot-Coil Compression for Accelerated K-Space Reconstruction in Interleaved EPI DWI |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of |
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A novel compression method, shot-coil compression, is developed and implemented to a k-space reconstruction method SYMPHONY for computation acceleration. By this technique, high resolution multishot diffusion images can be reconstructed with much less reconstruction time. The basic idea of the proposed method is to remove the redundant multi-coil and multi-shot data while reserving most useful information. Simulation and in-vivo experiment were designed and the results validated the effectiveness of the shot-coil compression method. |
| 3216 | Computer #50 |
Robust GRAPPA Calibration in Phase Cycled bSSFP |
1Electrical Engineering, Stanford University, Stanford, CA, United States |
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In phase cycled bSSFP, there is considerable motivation to use undersampling to mitigate long scan times. Direct application of a GRAPPA or SPIRiT reconstruction involves performing calibration separately for each phase cycled image. However, the receiver sensitivities are equivalent for all phase cycles, and this redundancy should be accounted for to improve calibration quality. Here, we describe a method for calculation of a single GRAPPA kernel over all phase cycles simultaneously, which is shown to improve calibration quality. |
| 3217 | Computer #51 |
Effects of ACS line geometry in volumetric GRAPPA: A Comparative Study |
1Gachon Advanced Institute for Health Science and Technology, Gachon University, Incheon, Korea, Republic of |
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In this study, the effects of the aspect ratio of ACS lines with respect to the phase-encoding and partition-encoding steps are investigated for 3D GRAPPA reconstruction algorithms such as EX-3D-GRAPPA and SK-3D-GRAPPA. When the ACS lines are acquired by carefully considering the dimensions of the image matrices, the quality of the reconstructed images can be improved. |
| 3218 | Computer #52 |
Effect of parallel imaging reference scan on fMRI evaluated at 7T. |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States |
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Investigation on the effect of reference or calibration scans needed to reconstruct undersampled MRI data. The study covers 3 different acceleration factors, and 6 different reference acquisitions. It is found that scan to scan variability for common acceleration factors is larger than any difference in tSNR between FLASH and FLEET, and that segmented EPI and single-shot are inferior to FLASH and FLEET acquisitions. |
| 3219 | Computer #53 |
Parallel Imaging Reconstruction from Undersampled K-space Data via Iterative Feature Refinement |
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology,Chinese Academy of Sciences, shenzhen, China, People's Republic of, 2University at Buffalo,The State University of New York, New york, NY, United States, 3Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong |
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Compressed sensing based parallel imaging is an essential technique for accelerating MRI scan. However, most existing methods are still suffering from fine structure loss. This paper proposes an iterative feature refinement scheme for improving the reconstruction accuracy. We have incorporated the feature descriptor into the self-feeding sparse SENSE (SFSS) framework. Results on in-vivo MR dataset have shown that the descriptor is capable of capturing image structures and details that are discarded by SFSS and thus presents great potential for more effective parallel imaging. |
| 3220 | Computer #54 |
The influence of sampling density and randomness in Variable Density Poisson Disk undersampling on Parallel Imaging Compressed Sensing |
1Image Sciences Institute, UMC Utrecht, Utrecht, Netherlands |
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We studied the effect of sampling density and randomness in Variable Density Poisson Disk (VDPD) undersampling patterns on Parallel Imaging Compressed Sensing (PICS) reconstruction errors. PICS reconstructions were performed on 3 datasets (knee, prostate, and brain) which were retrospectively undersampled with 110 VDPD undersampling patterns each. We found major differences in Normalized Root Mean Squared Errors when using different sampling densities, while the influence of randomness in patterns of the same sampling density was minor. Furthermore, the optimal sampling density varied per dataset. This shows that ad hoc choices of VDPD sampling density can result in significantly worse PICS reconstructions. |
| 3221 | Computer #55 |
Improved aliasing suppression in steady-state, parallel imaging using inner volume excitation Introduction |
1University of Michigan, Ann Arbor, MI, United States |
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A method of suppressing incomplete aliasing artifacts in accelerated MRI by combining inner-volume steady-state imaging with parallel imaging (GRAPPA) is proposed. Its effectiveness is evaluated across different net acceleration factors (R=1.75-3.64). The normalized root mean squared error inside the region of interest is generally suppressed by approximately a factor of 2 when inner volume excitation is adopted. |
| 3222 | Computer #56 |
A comparison of volumetric GRAPPA algorithms for in-vivo MRI |
1Gachon Advanced Institute of Health Sciences and Technology, Gachon University, Incheon, Korea, Republic of |
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To compare the volumetric GRAPPA algorithms in the presence of physiological artifacts, five different algorithms were used, i.e., 2D-GRAPPA-OP, 3D-GRAPPA, EX-3D-GRAPPA and SK-3D-GRAPPA. The performance of algorithms were compared using the root mean squared error (RMSE) of the image reconstructed from fully acquired 3D in-vivo k-space data and the image reconstructed using different reconstruction algorithms from undersampled dataset. |
| 3223 | Computer #57 |
Revisiting adaptive regularization for self-calibrated, dynamic parallel imaging reconstruction |
1FMRIB, University of Oxford, Oxford, United Kingdom |
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In this work we demonstrate a simple method for reducing error in k-t under-sampled parallel imaging by subtracting a dynamic, low-rank time-series estimate prior to un-aliasing reconstruction. This estimate is generated directly from the under-sampled data by selecting the first $$$r$$$ components of a singular value decomposition after sliding-window reconstruction, and removes signal variance that might otherwise contribute to residual aliasing. This method is motivated by the observation that the highest variance components in time-series data are typically low-frequency, and well characterised by a sliding window filter. |
| 3224 | Computer #58 |
Improved robustness of parallel imaging in 3D multi-slab diffusion imaging using an adapted FLEET approach |
1FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 2Maastricht Brain Imaging Center, Department of Cognitive Neuroscience, Maastricht University, Maastricht, Netherlands |
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In this work, we developed and evaluated a method for reducing motion sensitivity of auto-calibration data for parallel imaging in 3D MRI, with application to high-resolution diffusion imaging at ultra-high field. With the proposed Slice-FLEET method, we successfully achieve high resolution (1mm isotropic) diffusion MRI with high SNR and high b values. |
| 3225 | Computer #59 |
Improved Homogeneity of B1+ and Signal Intensity at 7T Using a Parallel Transmission on Human Volunteers |
1Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan, 2Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan, 3Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Yahaba, Japan, 4MR Applications and Workflow, GE Healthcare, Tokyo, Japan |
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The aim of our study was to compare the homogeneity of B1+ map and clinical gradient-echo images at 7T between two-channel pTx and qTx. MRS phantom with a water pack and six volunteers were scanned by 7T MRI, and the homogeneity was evaluated by coefficient of variation of region-of-interest analysis. The signal homogeneities of B1+ map and GRASS image were better in pTx than in qTx, however the homogeneity of SPGR images had no difference between pTx and qTx, in both phantom and volunteer studies. These results might facilitate the development of pTx. |
| 3226 | Computer #60 |
Image Intensity Corrections in ESPIRiT from Eigenvalue Based Spatially Variant Sensitivity Map Rescaling Modifications |
1Alltech Medical Systems, Chengdu, China, People's Republic of, 2Alltech Medical Systems America, Cleveland, OH, United States |
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Images from accelerated acquisition and ESPIRiT reconstruction show inhomogeneous intensity from the original array coil sensitivity distributions, because of the arbitrarily scaled sensitivity (eigenvector) maps. We propose to use the corresponding eigenvalues to restore the proper relative sensitivity scaling in the maps as a method of intensity bias correction, to help better visualization of the anatomies. |
| 3227 | Computer #61 |
Fast dynamic imaging using multi-shell sampling for variable k-space density k-t acquisitions |
1Philips Healthcare, Hamburg, Germany, 2Department of Radiology, University Hospital of Cologne, Cologne, Germany |
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In this work a new multi shell variable density k-t space sampling scheme for highly accelerated acquisitions with sheared grid k-t space sampling and an adapted reconstruction framework based on a linear reconstruction is proposed. The proposed method is evaluated on numerical phantom data and compared to a conventional k-t PCA acceleration. The proposed method is shown to be comparable to conventional k-t PCA for moderate acceleration factors while outperforming conventional k-t PCA for high accelerations factors allowing for ultra-fast dynamic MRI. |
| 3228 | Computer #62 |
Accelerating Real-time MRI of speech using spiral through-time GRAPPA |
1Electrical Engineering, University of Southern California, Los Angeles, CA, United States, 2Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, 3Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States |
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Real-time MRI (RT-MRI) is a powerful tool to safely assess and quantify the vocal tract dynamics during speech production. In this work, we evaluate the potential of a fast linear reconstruction method through-time GRAPPA (TT-GRAPPA) to efficiently exploit the acceleration capabilities offered by a custom 8-channel upper-airway coil and spiral trajectories and utilize it to improve RT-MRI of speech in visualizing rapid articulatory dynamics. We report feasibilities of 3 to 4 fold acceleration, and demonstrate up to 52 frames per second (18ms/frame) in single slice (2.4 mm2), and three-slice (4.5mm2) imaging. imaging. |
| 3229 | Computer #63 |
SENSing-SPICE: Integrating Parallel Imaging with Subspace-Based 3D 1H-MRSI |
1Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 2Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States |
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We present a method which reduces the acquisition time of 3D 1H-MRSI through the integration of parallel imaging and subspace-based imaging. The proposed method enables a better combination of speed, resolution, and SNR than can be provided by parallel imaging or subspace-based imaging alone; however, the removal of nuisance signals from under-sampled MRSI data requires significantly higher reconstruction accuracy than in conventional parallel imaging applications. We solve this problem by incorporating spatial and spectral constraints as well as sensitivity encoding into a recently proposed Union-of-Subspace model. We demonstrate the effectiveness of our method using in vivo data of the brain. |
| 3230 | Computer #64 |
Improved In-plane SENSE PROPELLER with Multi-Step Joint-Blade Reconstruction |
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 3Department of Biomedical Engineering, Tsinghua University, Beijing, China, People's Republic of |
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This work addresses three problems for in-plane SENSE-accelerated PROPELLER: generally amplified noise, increased artifact with narrow blades, and degraded motion correction with wide blades. We show that a novel reconstruction method - multi-step join-blade (MJB) SENSE can lead to higher SNR and less narrow-blade artifact than conventional SENSE reconstruction. In addition, k-space truncation is used to improve the motion correction robustness. We also show that additional iterations can enhance MJB SENSE. This new method can greatly benefit future SENSE PROPELLER studies with improved image quality. |
| 3231 | Computer #65 |
Super Slice Interpolation (SSI) from Parallel MRI Data |
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 3School of Biomedical Engineering and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China, People's Republic of |
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This work develops a novel super slice interpolation (SSI) method that exploits sensitivity variation along the slice direction to decrease slice thickness in multi-slice MRI. The phantom and in vivo head imaging results demonstrate that SSI successfully generates thinner slice images from a set of thick images acquired with multiple receiver coils, without the need of modifying pulse sequences. The proposed SSI method has potential to obtain more slices with decreased thickness in scenarios where acquisition window or specific absorption rate limits the available number of slices. |
| 3232 | Computer #66 |
Calibration-free Parallel Imaging Using Randomly Undersampled Multichannel Blind Deconvolution (MALBEC) |
1Electrical Engineering, The State University of New York at Buffalo, Buffalo, NY, United States, 2Biomedical Engineering, The State University of New York at Buffalo, Buffalo, NY, United States |
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This abstract presents a novel reconstruction method for parallel imaging that does not require auto-calibration data. The method formulates the image reconstruction problem as a multichannel blind deconvolution problem in k-space where the data are randomly undersampled in all channels. Under this formulation, the k-spaces of the desired image and coil sensitivities are jointly recovered by finding a rank-1 matrix subject to the data consistent constraint. Experimental results demonstrate that the proposed method is able to achieve better reconstruction results than the state-of-the-art calibration-less parallel imaging methods. |
| 3233 | Computer #67 |
A novel reconstruction method for high-resolution DWI in zoomed FOV imaging with parallel acquisitions at 1.5T |
1Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China, People's Republic of, 2The Laboratory for Medical Electronics, School of Biological Sciences and Medical Engineering, Southeast University, Nanjing, China, People's Republic of, 3Philips Healthcare, Suzhou, China, People's Republic of, 4Department of Radiology, the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China, People's Republic of |
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A new reconstruction method is presented for high-resolution DWI in zoomed FOV imaging with parallel acquisitions. this method can reduce noise and artifact in the reconstructed images compared to conventional SENSE magnitude average. |
| 3234 | Computer #68 |
Can multi-slice information improve the conditioning of in-plane acceleration? |
1Donders Centre for Cognitive Neuroimaging, Radboud University, Nijmegen, Netherlands |
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To improve the conditioning of GRAPPA enabled in-plane acceleration by using phase encoding shifts of spatially neighbouring slices. Parallel imaging offers the possibility to reduce acquisition time or echo train lengths needed to fully encode a given object. New k-space trajectories and reconstruction techniques offer the possibility of large acceleration factors in the slice direction (in the case of SMS) or in either of the two phase encoding directions in volumetric imaging. While 2D and 3D reconstructions can be seen on a common framework, it is not straightforward to, in conventional multi-slice imaging, have more than 3-4 fold inplane acceleration. |
| 3235 | Computer #69 |
The potential of 256 channel high density receive arrays in combination with 2DCAIPIRINHA at 7T |
1Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2MR Coils B.V., Drunen, Netherlands |
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There is an overall drive to high speed, high resolution brain MRI. High density receive arrays have proven to be a very valuable tool in this process. However, alternative acquisition strategies like 2DCAIPIRINHA have shown to be highly effective in acceleration. We investigated whether a 256ch high density receive array with or without 2DCAIPIRINHA can still outperform a 32ch array with 2DCAIPIRINHA. |
| 3236 | Computer #70 |
SPOT: SPIRiT Image Reconstruction with Custom Kernel Geometry |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Neurology, University of Pennsylvania, Philadelphia, PA, United States, 3Hangzhou Normal University, Hangzhou, Zhejiang, China, People's Republic of |
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In SPIRiT image reconstruction the kernel usually consists of all elements within a square. The number of elements in such a kernel increases rapidly as the kernel size increases, especially for 3D reconstructions. Thus, a large kernel requires a sizable calibration region in k-space and demands significant time for calibration. In this work we proposed and validated a new image reconstruction approach that uses a custom SPIRiT kernel geometry, which we call SPOT. We show that a SPOT kernel is much faster to compute and results in no loss of image quality compared to the traditional SPIRiT kernel. |
| 3237 | Computer #71 |
Increasing Temporal Resolultion of DSC-perfusion MRI using 3D Distributed Spirals and Through-Time GRAPPA |
1Neuroimaging Research, Barrow Neurological Institute, Phoenix, AZ, United States |
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DSC-MRI requires high temporal resolution to accurately measure perfusion parameters in vivo. Using GRAPPA parallel imaging, it is possible to achieve whole-brain coverage while maintaining high temporal sampling. The proposed method combines a 3D dual echo spiral sequence with through-time GRAPPA for whole-brain coverage with < 1 second temporal resolution. |
| Exhibition Hall | Tuesday, May 10, 2016: 11:00 - 12:00 |
| 3238 | Computer #1 |
Simultaneous Multi-Slice Imaging with ESPIRiT |
1Advanced Application, Alltech Medical Systems, Chengdu, China, People's Republic of, 2Advanced application, Alltech Medical Systems America, Cleveland, OH, United States |
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Simultaneous multi-slice (SMS) acquisitions with SENSE reconstruction rely greatly on the fidelity of coil sensitivity maps. Due to the difficulty on choosing polynomial orders, traditional polynomial fitting method often results in residual spatial oscillations or influence from imaging content, which compromise the reconstruction quality. ESPIRiT (An Eigenvalue approach to auto-calibrating parallel MRI) is a new technique to estimate sensitivity map from auto-calibration signal. It is a sub-space based method that is highly robust to many types of errors because the estimated subspace automatically adapts to inconsistencies in the data. We propose to extend the simultaneous multi-slice imaging with ESPIRIT for higher-fidelity sensitivity distribution estimation and highly robust reconstruction. |
| 3239 | Computer #2 |
Comprehensive CG-SENSE reconstruction of SMS-EPI |
1Center for the Developing Brain, King's College London, London, United Kingdom |
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A 2D CG-SENSE framework is proposed aiming at an integrated treatment of the main error sources in SMS-EPI reconstruction. Our pipeline jointly estimates the sensitivity profiles, Nyquist ghosting parameters, and image to be unfolded. In addition, an artifact-SNR tradeoff is established at a pixel level. Assessment by a phantom experiment has shown that all the main functionalities of the method do help diminish reconstruction artifacts. Stable results have been obtained when applying the framework in a large cohort of motion corrupted fMRI and DWI neonatal studies. |
| 3240 | Computer #3 |
Improved Radial Sampling using Wave-CAIPI |
1University of Hawaii JABSOM, Honolulu, HI, United States |
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This abstract presents a method that applies sine waveforms to the imaging gradients in radial sampling. This concept is similar controlled aliasing in Parallel Imaging (CAIPI). It enhances the encoding power of coil sensitivities by introducing spatially varying convoultion. Improvement in image quality are observed in images reconstructed from undersampled (R=8) wave-radial data compared to images from undersampled (R=8) radial data acquired at 3T. |
| 3241 | Computer #4 |
Multi-Step Joint-Blade SENSE Reconstruction for Simultaneous Multislice PROPELLER |
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 3Department of Biomedical Engineering, Tsinghua University, Beijing, China, People's Republic of |
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For simultaneous multislice (SMS) PROPELLER, we propose multi-step joint-blade (MJB) SENSE reconstruction. In MJB SENSE, all blades are jointly reconstructed in three steps without relying on iterations. Compared to separately reconstructing individual blades, MJB SENSE substantially reduces noise amplification and narrow-blade artifact. MJB SENSE is also compatible with motion correction. With these advantages, MJB SENSE can be used to achieve very high MB factors in SMS PROPELLER. |
| 3242 | Computer #5 |
An iterative reconstruction method for dual-band EPI in small-animal studies |
1CiNet, National Institute of Information and Communications Technology, Suita, Japan, 2Department of Structural BioImaging, Kumamoto University, Kumamoto, Japan |
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We proposed an iterative reconstruction method which was effective and valid in reducing artifacts in dual-band EPI in animal scanners. This iterative reconstruction method could accurately separate collapsed k-space data acquired simultaneously from multiple slice locations. Our findings give rise to a more efficient multi-band EPI technique that can be used even with a scanner system equipped with relatively few receiver coil elements. |
| 3243 | Computer #6 |
Simultaneously Multi-Slice (SMS) Accelerated Interleaved EPI DWI using 3D K-space Reconstruction |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of, 2Vascular Imaging Laboratory, Department of Radiology, University of Washington, Seattle, WA, United States |
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Simultaneously multi-slice (SMS) has been a powerful tool for single-shot EPI DWI acceleration, but still not well established for interleaved EPI (iEPI) DWI acceleration. The main challenge is how to effectively combine slice un-folding and inter-shot phase correction. In this study, a 3D k-space reconstruction method for navigated SMS accelerated iEPI DWI has been proposed. An optimized acquisition for navigator is designed. Then slice un-folding and inter-shot phase correction are performed in a SMS 3D k-space. The performance is compared with ssEPI and un-accelerated iEPI DWI, and has been shown to be applicable for both 4-sh and 8-sh iEPI DWI. |
| 3244 | Computer #7 |
Simultaneous Multi-Slice Acquisition with Multi-Contrast Segmented EPI for Dynamic Contrast-Enhanced Imaging |
1Fraunhofer MEVIS, Bremen, Germany, 2mediri GmbH, Heidelberg, Germany, 3University Hospital Essen, Essen, Germany |
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The application of simultaneous multi-slice imaging to a segmented EPI allows the acquisition of multiple contrasts while retaining sufficient temporal resolution and spatial coverage. Contrast-enhanced perfusion measurements were performed on a pig’s hip/leg resulting in mainly muscle-perfusion images with separated S0 and T2* maps. The separation of the different signal contributions potentially allows for a quantitative analysis in contrast-enhanced dynamic imaging. |
| 3245 | Computer #8 |
Reconstruction of Simultaneous Multi-Slice EPI data using Dual-Polarity GRAPPA Kernels. |
1Radiology, Brigham and Women's Hospital, Boston, MA, United States, 2Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States |
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This work presents a new approach to reconstruct SMS-EPI data that employs Dual-Polarity GRAPPA (DPG). DPG accurately models non-linear EPI phase errors between data sampled on positive versus negative readout gradients. When applied to SMS-EPI data, DPG can simultaneously and robustly perform slice separation, recovery of missing data from in-plane acceleration, and slice-specific ghost correction. Phantom and in vivo results are compared to a conventional SMS reconstruction, and demonstrate that DPG reduces residual ghosts and ghosting-related phase interference artifacts. |
| 3246 | Computer #9 |
Echo-Shift wave-CAIPI with Simultaneous MultiSlice imaging for rapid susceptibility weighted FLASH |
1MGH/A.A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 2Zhejiang University, Hangzhou, China, People's Republic of, 3Boston Children's Hospital, Charlestown, MA, United States |
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Susceptibility weighted FLASH imaging provides exquisite soft tissue contrast at high spatial resolution and low distortion, but at a cost of lengthy acquisition time. In this work, we developed a highly efficient Echo-Shift wave-CAIPI technique and demonstrated its ability to provide 18-fold acceleration for FLASH acquisitions with minimal noise and artifact penalties. Instead of conventional single slice or slab echo-shift, we propose an echo-shift Simultaneous MultiSlice method to enable improved controlled aliasing and desirable volumetric noise averaging while avoiding slab edge artifacts. With this technique, we demonstrated high-quality 1.5 mm isotropic whole-brain susceptibility weighted FLASH at 3T and 7T in 36s. |
| 3247 | Computer #10 |
A Circular Echo Planar Sequence for Simultaneous Multi-Slice Imaging |
1John A Burns School of Medicine, University of Hawaii, Honolulu, HI, United States |
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This abstract presents a circular echo planar imaging sequence for simultaneous multi-slice imaging. A generalized SENSE reconstruction framework with ghost correction was utilized. Different sampling strategies including wave modulation, blipped-CAIPI, and hexagonal were examined. Phantom as well as human fMRI scanning at 3T are shown. |
| 3248 | Computer #11 |
Evaluating The Performance of Four Reconstruction Algorithms for Simultaneous Multi-Slice Imaging |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Center for Cognitive and Neurobiological Imaging, Stanford University, Stanford, CA, United States, 3Applied Sciences Laboratory West, GE Healthcare, Menlo Park, CA, United States |
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Several parallel imaging reconstruction algorithms have been proposed for simultaneous multi-slice (SMS) imaging, yet a thorough comparison of the algorithms still awaits investigation. In this study, the performance of four reconstruction algorithms are compared. Relative root-mean-squared error, g-factor, signal leakage, and reconstruction time are used as metrics for evaluating the performance. This work may provide a reference for the SMS community to choose from different reconstruction algorithms. |
| 3249 | Computer #12 |
Multiband TSE Imaging of the Fetal Brain at 3T |
1Centre for the Developing Brain, King's College London, London, United Kingdom, 2Biomedical Engineering, King's College London, London, United Kingdom, 3GyroTools, Zurich, Switzerland |
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Single-shot Turbo Spin-Echo (ss-TSE) sequences can provide excellent anatomical images of the fetal brain. However, due to the surrounding maternal tissue, full field of view encoding leads to long echo train lengths, impacting efficiency, causing high SAR and increased risk of motion artefact. In this abstract we present the implementation of multiband accelerated ss-TSE of the fetal brain, with a zoom variant that reduces both overall scan time and the need to encode a large FOV. In addition simultaneous sampling multiple slice locations should benefit the image registration step in subsequent 3D slice-to-volume reconstructions. |
| 3250 | Computer #13 |
Multiplexed multiband EPI for increased efficiency in fetal fMRI and dMRI |
1Centre for the developing brain, King's College London, London, United Kingdom |
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This abstract demonstrates combined multiband and multiplex imaging for fetal EPI based sequences such as used in diffusion and functional MRI. This application lends itself naturally to multiplex imaging, due to PNS and noise restrictions, EPI readout speeds are inherently limited so offsets the inevitable TE penalty from multiplex imaging. |
| 3251 | Computer #14 |
Ultrafast multi-slice MRI with segmented spatiotemporal encoding |
1Department of Electronic Science, Xiamen University, Xiamen, China, People's Republic of, 2Department of Communication Engineering, Xiamen University, Xiamen, China, People's Republic of |
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As a recently launched method, spatiotemporally encoded (SPEN) magnetic resonance imaging (MRI) has been broadened from single-slice scan to multi-slice scan. A new single-shot multi-slice full-refocusing SPEN MRI sequence was proposed. By utilizing a segment-selective pulse and a 180° chirp pulse and sequentially acquiring the signals of every slice among the encoded segment, the new method can lower the specific absorption rate (SAR) and improve the image quality compared to the existing one. Experimental results of phantom and in vivo rat brain verified the above conclusion. |
| 3252 | Computer #15 |
Half Fourier Acquisition Single Shot Turbo Spin Echo (HASTE) imaging using multiband (MB) excitation and Power Independent of Number of Slices (PINS) refocusing pulses at 3 Tesla |
1Donders Institute for Cognitive Neuroimaging, Radboud University Nijmegen, Nijmegen, Netherlands |
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HASTE sequences have high RF power deposition which particularly limits their use at high resolutions and high field strengths. In this work, TRAPS and fixed SAR Power Independent of Number of Slices (PINS)-refocusing pulses were used to reduce the power deposition. Multiband excitation pulses were added to enable arbitrary user-defined slice orientations, with the added benefit of accelerating the acquisition due to the simultaneous excitation of multiple slices. Good image quality was obtained for a MB4-HASTE protocols with 3.1 and 1.1 mm resolution, and a whole-brain MB6-HASTE protocol with 1.1 mm resolution. |
| 3253 | Computer #16 |
Shortening nonlinear phase multiband refocusing pulses with VERSE |
1CMRR, Radiology, University of Minnesota, Minneapolis, MN, United States |
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Current high resolution, whole brain diffusion MRI protocol at 7T for the Human Connectome Project uses linear phase multiband (MB) refocusing pulses that have duration longer than 10 ms. Recent studies show that shorter duration can be obtained by designing nonlinear phase MB refocusing pulses. In this study, we designed root-flipped MB and hyperbolic secant (HS1) based MB refocusing pulses and investigated how the variable rate selective excitation (VERSE) principle can be used to further reduce the pulse duration. Our results suggest that both root-flipped and HS1 based MB refocusing pulses can be shortened by VERSE. |
| 3254 | Computer #17 |
Effects of Multiband Acceleration on High Angular Resolution Diffusion Imaging data collection, processing, and analysis. |
1Biomedical Engineering, University of Arizona, Tucson, AZ, United States, 2Psychiatry, University of Arizona, Tucson, AZ, United States, 3Electrical and Computer Engineering, University of Arizona, Tucson, AZ, United States, 4Radiology, University of Arizona, Tucson, AZ, United States |
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Multiband imaging allows for greater imaging speeds when collecting diffusion weighted MR images. As shown in this work, this saving in time results in small changes in several stages of diffusion image processing including tensor fitting and the associated calculation of scalar values such as FA, fiber orientation distribution calculation as in constrained spherical deconvolution, and tractography. |
| 3255 | Computer #18 |
Multiband Echo-Shifted EPI (MESH) fMRI |
1Radboud University, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, Netherlands, 2Radiology, Case Western Reserve Univesity, Cleveland, OH, United States, 3Erwin L. Hahn Institute, University Duisberg-Essen, Essen, Germany |
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Multiband Echo-Shifted EPI (MESH) is a combination of echo shifted 2D multi-slice EPI, in-plane and multiband acceleration. An additional EPI readout is inserted in the dead-time between slice selection and the multiband EPI readout. It is useful especially for low static magnetic field strengths (long optimal TE) and lower spatial resolutions (short EPI readout). It is shown that echo shifting gradients do not affect tSNR. Compared to standard and multiband EPI similar RS fMRI results are obtained at the group and individual subject level. MESH offers a further acceleration in image acquisition for fMRI at no loss in sensitivity. |
| 3256 | Computer #19 |
Revisited Multislice Distributed Inversion Recovery towards an Efficient Neonatal MR Examination. |
1Centre for the Developing Brain, Department of Perinatal Imaging and Health, King's College London, London, United Kingdom |
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Multislice multishot Inversion Recovery sequences as implemented in standard systems are often not optimized for efficiency. This becomes a critical factor when imaging neonates, where T1 is longer and the Inversion Time needs to increase to maintain the desired contrast. In this study, we have optimized a standard Inversion Recovery sequence and used it for an optimised neonatal protocol. The proposed sequence provides a total scan time reduction of 44% with identical imaged contrast and resolution. |
| 3257 | Computer #20 |
RF-Encoding for Simultaneous Multi Slab Imaging |
1Stanford University, Stanford, CA, United States |
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Simultaneous-Multi-Slab-Imaging is a promising approach for high resolution DW-EPI (<1mm) where the slice profile of a typical multi-band RF-pulse limits the spatial resolution for single-shot DW-EPI. Like every multi-band technique, slab separation during a parallel imaging reconstruction requires a combination of coil sensitivity variation and k-space encoding. The most prominent way is blipped-CAIPIRINHA where k-space encoding along the slice direction is achieved by adding small gradient blips in z-direction to the EPI readout. Here we demonstrate how multi-band RF phase modulation can be used as an alternative way to encode along the slab dimension without affecting intra-slab phase encoding. The use of phase modulated RF-pulses decouples encoding between the logical intra- and inter-slab directions that are otherwise linked because there is only one physical z-gradient axis. |
| 3258 | Computer #21 |
Accelerated Simultaneous Multi-Slice (SMS) fMRI using spiral acquisition and low rank plus sparse (L+S) image reconstruction |
1Department of Medicine, University of Hawaii, Honolulu, HI, United States, 2Department of Radiology and Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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Sub-second whole brain imaging using Simultaneous Multi-Slice (SMS) imaging is of particular interest in Blood Oxygen Level Dependent (BOLD) functional Magnetic Resonance Imaging (fMRI). Faster acquisitions with higher temporal sampling of the BOLD time course provides several advantages including increased sensitivity in detecting functional activation, the possibility of filtering out physiological noise for improving temporal SNR, and freezing out head motion. The most commonly used strategy to accelerate image acquisition time using SMS involves using parallel imaging methods. We propose to accelerate SMS imaging by under sampling the number of excited slices in the kz-t domain and L+S matrix decomposition method for reconstruction of slice aliased functional images. We present human fMRI results at 3T using 3D spiral sampling with SMS excitation and L+S reconstruction of the aliased slice data. |
| 3259 | Computer #22 |
Reconstruction of multiband MRI data using Regularized Nonlinear Inversion |
1Department of Diagnostic and Interventional Radiology, University Medical Center Göttingen, Göttingen, Germany, 2German Centre for Cardiovascular Research (DZHK), University Medical Center Göttingen, Göttingen, Göttingen, Germany |
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Multiband MRI can be used to acquire several slices at the same time. Here, we propose a new method of multiband MRI based on Regularized Nonlinear Inversion (NLINV). This method does not require a priori knowledge about the coil sensitivities. Simultaneous estimation of images and coil sensitivities of two slices is demonstrated from six-fold undersampled data for a simulated multi-band acquisition. |
| 3260 | Computer #23 |
Optimization of High-Resolution Slice-Accelerated Inversion Recovery T1 Mapping at 7T |
1Siemens Healthcare, Portland, OR, United States, 2Oregon Health & Science University, Portland, OR, United States |
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Parametric T1 mapping using inversion recovery has competing requirements for speed, SNR, spatial resolution, anatomical coverage, and adequate sampling of the longitudinal magnetization recovery. Potential sources of slice-to-slice variability in quantitative T1 maps are investigated, including slice cross talk due to imperfect slice profiles, and the range of TIs used to fit each slice. It is demonstrated that T1 relaxometry benefits significantly from slice acceleration techniques in not only scan time & slice coverage, but in its ability to reduce quantitative errors by allowing the same TI sampling across all slices. |
| 3261 | Computer #24 |
Noise amplification vs. resolution tradeoff in the SLIDER technique |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States |
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An investigation into the noise and resolution performance of SLIDER using a series of shifted low-resolution images to obtain a single high-resolution. The evaluation is performed both theoretical and experimentally using a FLASH acquisition, to remove experimental limitations from understanding the merits of the technique. |
| Exhibition Hall | Tuesday, May 10, 2016: 11:00 - 12:00 |
| 3262 | Computer #25 |
Improving Time Efficiency for T2-weighted Fat-Water Imaging by Using Multiband Simultaneous Multi-Slice Accelerated TSE Dixon |
1Siemens Healthcare, Minneapolis, MN, United States, 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States |
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Dixon technique requires at least two images with different echo times, which increases TSE echo spacing and TR, and therefore prolongs total acquisition time. Slice acceleration may help improve imaging efficiency of TSE fat-water Dixon imaging. In this study, we develop a multiband slice accelerated TSE Dixon sequence and demonstrate the feasibility of SMS TSE Dixon acquisition for efficient T2-weighted fat-water imaging. |
| 3263 | Computer #26 |
High Performance Volumetric 3T Breast Acquisition: A Foundation for Multi-Parametric Imaging |
1Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 2Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States, 3Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States |
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We present a 3D T1-Weighted radial trajectory suited to work with IDEAL fat/water separation. Some relevant characteristics are: rapid acquisition, reliable fat suppression, and high resolution despite significant data undersampling. The method is demonstrated in 3T bilateral breast MR imaging where isotropic resolution of 0.8 mm is achieved. In addition, we show the value of high count channel array for breast imaging. |
| 3264 | Computer #27 |
Bipolar time-interleaved multi-echo gradient echo imaging for high-resolution water-fat imaging |
1Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, 2Philips Research, Hamburg, Germany, 3Philips Healthcare, Hamburg, Germany, 4Radiology, Phoenix Children’s Hospital, Phoenix, AZ, United States, 5Zentralinstitut für Medizintechnik, Technische Universität München, Garching, Germany |
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As the spatial resolution of a multi-echo gradient-echo imaging sequence increases, the echo time step increases resulting in an increased echo time step and an echo time selection that degrades the noise performance of water-fat separation. Time-interleaved gradient echo imaging combined with bipolar (flyback) gradients can achieve reasonable echo time steps at high resolution without dramatically increasing scan time. However, bipolar gradients are associated with known phase errors problems, which can lead to fat quantification errors. The present work develops a methodology for acquiring bipolar time interleaved multi-echo gradient echo data and for correcting the relevant phase errors. |
| 3265 | Computer #28 |
Silicone, fat, and water separation using a single-pass 3D Dixon acquisition |
1Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX, United States, 2MR Applications and Workflow, GE Healthcare, Waukesha, WI, United States, 3Department of Radiology, Stanford University, Stanford, CA, United States |
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Separation of silicone, fat, and water is performed by using a two-step Dixon processing algorithm and a bipolar triple-echo readout in a 3D FSE sequence. The echoes are spaced for conventional water-fat separation, but the first and last echoes are also used to generate a phase map with double the phase evolution for resolving fat from silicone, which are relatively close in terms of chemical shift. Individual images of each of the three species are reconstructed in phantom and human data. The proposed method demonstrates improved SNR efficiency and robustness to field inhomogeneity compared to conventional saturation and inversion recovery techniques. |
| 3266 | Computer #29 |
Incorporation of Prior Knowledge of Main Field Inhomogeneity in Dixon Methods |
1Philips Research, Hamburg, Germany, 2Philips Healthcare, Best, Netherlands, 3Imaging Division, University Medical Center Utrecht, Utrecht, Netherlands |
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The robustness of Dixon methods often deteriorates close to large main field inhomogeneity. To resolve this problem, the exploitation of prior knowledge of magnet imperfections is considered in this work. Magnet-induced main field inhomogeneity is modeled to predict and correct spatial variations of the phase in single-echo images before the separation of water and fat signal. Improved fat suppression is demonstrated with this approach in first-pass peripheral angiography, in particular in the corners of the large FOVs. |
| 3267 | Computer #30 |
Comparison of Gradient Echo MRI Water-Fat separation and single voxel 1H MRS for liver fat fraction measurements in a dietary intervention study at 3T |
1Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, 2NIHR Nottingham Digestive Diseases Research Unit, University of Nottingham, Nottingham, United Kingdom, 3School of Life Sciences, University of Nottingham, Nottingham, United Kingdom |
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This study compared hepatic fat fraction measured using MRS and gradient echo MRI at 3T. Fitting algorithms using a single fat peak and multiple fat peaks were compared with MRS data at TE=20ms and also T2-corrected MRS. Individual differences between T2 values of water and fat calculated from MRS were also used to estimate the difference between R2*-water and R2*-fat and included in the multi peak fitting per subject. The results showed a good correlation between multi-peak and MRS data (R2 = 0.9), but applying T2-correction to MRS increased the scatter (R2 = 0.67) and systematic error (gradient = 1.34). Using the new R2* corrected fitting algorithm resulted in similar scatter (R2 = 0.66) but improved systematic error (gradient = 1.09). The results from this study indicate the dual-R2* fitting is important at 3T and further developments should be made to optimize these methods. |
| 3268 | Computer #31 |
Path based phase estimation for fat suppression near metal implants |
1Electrical and Computer Engineering, University of Canterbury, Christchurch, New Zealand, 2Radiology, Stanford University, Stanford, CA, United States |
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Being able to perform robust Dixon imaging near metal implants would allow for improved contrast-enhanced fat suppression. This requires accurate calculation of the phase shift due to the B0 field variation. We present a new technique where the phase is first estimated at the outer edges of the image. The method works inwards along a set of adjacent paths, finishing at the boundary of the implant. The described method is used to successfully separate fat and water in the vicinity of a titanium hip replacement, with phantom results shown. |
| 3269 | Computer #32 |
Improving Parameter Mapping in MRI Relaxometry and Multi-Echo Dixon using an Automated Spectral Denoising |
1Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany, 2Research Training Group 1773 “Heterogeneous Image Systems”, Erlangen, Germany, 3MR Applications Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany, 4Department of Radiology, Loma Linda University Medical Center, Loma Linda, CA, United States |
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Magnitude-based parameter fitting is commonly used for relaxometry and multi-echo Dixon but introduces a bias for relaxation and fat fraction estimates, particularly for a low signal-to-noise ratio and high relaxation. The application of an automated, patchwise denoising to the multi-echo image series prior to parameter fitting, considerably increased the SNR; thus, reducing the bias and standard deviation in the estimates of the fit. Our findings were validated on both numerical and in-vivo experiments. |
| 3270 | Computer #33 |
Two-point fat water separation using safest path region growing with self-feeding phasor estimation algorithm |
1Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, People's Republic of, 2University of Chinese Academy of Sciences, Beijing, China, People's Republic of |
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A novel two-point fat water separation method using safest path region growing with self-feeding phasor estimation algorithm is proposed. The phasor map is estimated by multiresolution region growing scheme where the seed pixels identification and region growing scheme is performed independently between coarser resolutions, avoiding the erroneous propagation between resolutions. The “self-feeding” mechanism when merging the phasor maps ensures the reliability of seed pixels selection at the finest resolution. The algorithm was tested on c-spine and abdomen data and shown to be robust in fast varying field and disjoint areas. |
| 3271 | Computer #34 |
Increased measurement precision for fatty acid composition mapping by parameter reduction |
1Karolinska University Hospital, Stockholm, Sweden |
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An imaging method for mapping Fatty Acid Composition using three triglyceride spectrum model parameters (FAC3) was modified into mapping Fatty Acid Composition with only one spectrum model parameter (FAC1), namely the average number of double bonds per triglyceride (ndb). Images of a patient with a lipoma were reconstructed using both methods. The FAC3 ndb map showed large-scale variation from left to right, giving significant variation between subcutaneous adipose tissue locations. Measurements from the FAC1 ndb map were consistent within the adipose tissue, offering a higher level of confidence and more precise measurements. |
| 3272 | Computer #35 |
A Fast and Globally Optimal 3-D Graph Search Algorithm for Phase Unwrapping in MRI with Applications in Quantitative Susceptibility Mapping (QSM) |
1Electrical and Computer Engineering, University of Iowa, Iowa City, IA, United States, 2Radiology Oncology, University of Iowa Hospitals and Clinics, Iowa City, IA, United States, 3Radiology, University of Iowa Hospitals and Clinics, Iowa City, IA, United States |
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Phase wrapping is a classic problem in many fields of study. In MRI, Unwrapping the phase in the estimation of B0 field inhomogeneity maps is challenging commonly due to the presence of a large field inhomogeneity, anatomical discontinuities or low SNR in certain regions of the map (e.g. boundaries). We propose a general phase unwrapping method that exploits the smoothness of the field map in three spatial dimensions. The method is solved using a linear-convex constrained graph search algorithm that provides the globally guaranteed optimal solution without over-smoothing effect. The proposed scheme aims to produce a robust solution for field map estimation that will further improve the quality of quantitative susceptibility mapping (QSM). |
| 3273 | Computer #36 |
Analysis of Bias with SNR in Multi-echo Chemical Shift Encoded Fat Quantification |
1MR Applications and Workflow, GE Healthcare, Madison, WI, United States, 2Radiology, University of Wisconsin-Madison, Madison, WI, United States, 3MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States, 4Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 5Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 6Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States |
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Multi-echo chemical shift encoded techniques provide accurate fat quantification over a broad range of fat-fractions and acquisition parameters. In order to be accurate, these techniques must correct for all relevant confounding factors. Emerging applications (eg: fat quantification with high spatial resolution or in iron overloaded tissues) can result in data with significantly lower signal-to-noise ratio (SNR) compared to previously established applications. In this work, we characterize the accuracy of current noise bias correction techniques for fat quantification in the low SNR regime and show simple modifications may enable accurate fat quantification for a wider range of SNR. |
| 3274 | Computer #37 |
DEVELOPMENT AND MULTI-CENTER VALIDATION OF A NOVEL WATER-FAT-IRON PHANTOM FOR JOINT FAT AND IRON QUANTIFICATION |
1Radiology, University of Wisconsin - Madison, Madison, WI, United States, 2Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 3Radiology, Duke University, Durham, NC, United States, 4Center for Advanced Magnetic Resonance Development, Duke University, Durham, NC, United States, 5Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, 6Medical Physics, University of Wisconsin-Madison, Madison, WI, United States |
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The need for rapid and non-invasive assessment of fat and iron deposition has become increasingly important given the high prevalence of obesity and obesity-related comorbidities as well as the need for monitoring chelation treatment in patients with iron overload. Recent advances in gradient-echo imaging have enabled the simultaneous quantification of fat and iron concentrations throughout the body. To ensure fidelity of these quantitative techniques, validation studies must be performed, ideally with initial testing in phantoms. In this work, we report on the development of a water-fat-iron MRI phantom that exhibits single-R2* decay, with controllable proton-density fat fraction (PDFF) and iron concentration. The purpose of this work is: 1) to describe the development of the water-fat-iron phantom, and 2) to assess the multi-center, multi-vendor reproducibility of joint fat and iron quantification using this phantom. |
| 3275 | Computer #38 |
A Novel Phase Unwrapping Method Based on Pixel Clustering and Local Surface Fitting with Application to Water-Fat Separation |
1School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu, China, People's Republic of, 2School of Biomedical Engineering and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China, People's Republic of, 3Philips Healthcare, Guangzhou, China, People's Republic of, 4Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 5Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, People's Republic of |
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Current phase-unwrapping algorithms are challenged by rapid phase variations, noise and disconnected regions. We propose a novel phase-unwrapping method based on the observation the phase local difference (pLD) and complex local difference (cLD) maps. The proposed algorithm first clusters pixels into disconnected regions by thresholding the cLD map and then performs local polynominal surface fitting (LPSF) to unwrap phase with the knowledge of wrapping locations identified by thresholding the pLD map. Both simulation and in vivo results demonstrate that the proposed method can correctly unwrapped phase even in the presence of rapid phase variation, low SNR, and disconnected regions, and has great potential application to phase-related MRI in practice. |
| 3276 | Computer #39 |
Modified Single-Echo Dixon Imaging for Improved SNR and CNR in Contrast-Enhanced MRA |
1Philips Research, Hamburg, Germany |
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Chemical shift encoding-based water-fat imaging, or Dixon imaging, is of recent interest in MRA. Single-echo Dixon methods are particularly appealing for this application because of their potential for decreasing scan times. This work suggests modifications to existing single-echo Dixon methods and demonstrates their benefits, primarily improvements in SNR and CNR, in contrast-enhanced peripheral MRA. |
| 3277 | Computer #40 |
Separation of Abdominal Subcutaneous Adipose Tissue (SAT) and Visceral Adipose Tissue (VAT) based on Wheel-Template in MRI |
1Dept. of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, Hong Kong |
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This abstract introduces the use of wheel-template to perform segmentation on subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) at the abdominal region. The proposed method detects narrow regions between SAT and VAT, and uses line cut to separate two types of tissues based on MRI data. It performs well on obese individuals and the obtained results are correlated to those obtained from a semi-automatic method. A quantitative measurement of SAT and VAT is important as they are developed from different pathways and suggested to be related to different chronic diseases. |
| 3278 | Computer #41 |
Analytical Three-Point Dixon Method Using a Global Graph Cut |
1Radiology, Uppsala University, Uppsala, Sweden |
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When reconstructing chemical shift encoded water-fat images so called water-fat swaps due to incorrect phase maps can be a significant problem, limiting clinical assessment and quantitative measurements. A method is presented for solving the problem in the case of 3 echoes, assuming only a fix intra-echo spacing. Two possible solutions are analytically calculated for each voxel. The correct global solution is then found using a graph-cut method. The method succeeds where a region-growing reference method fails at low SNR. The presented method runs quickly and uses only one parameter that can be set automatically, which should allow for online implementation. |
| 3279 | Computer #42 |
Fat Residue Removal by SENSE in EPI and DW-EPI |
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 3Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of |
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In this abstract, we proposed to use parallel imaging method to remove the fat residue in EPI applications. In EPI, fat is shifted along the phase encoding direction and can be treated as another simultaneously |
| 3280 | Computer #43 |
Characterization of Brown Adipose Tissue using Multi-Varying-Peak MR Spectroscopy (MVP-MRS) |
1Bioimaging Research Center, University of Georgia, Athens, GA, United States, 2Xidian University, Xian, China, People's Republic of, 3Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States |
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Differentiation of brown adipose tissue (BAT) from white adipose tissue (WAT) using magnetic resonance imaging (MRI) is clinically important to treat obesity, diabetes and heart disease. In contrast to the traditional Dixon model of single fat- and water-peak or fixed multi-fat-peak models, we propose a Multi-Varying-Peaks MR Spectroscopic (MVP-MRS) model, based on MR imaging data acquired with multiple echoes, to better characterize chemical structures of the fatty acid (saturated vs. unsaturated). Compared with traditional classification of BAT and WAT using fat fraction or proton relaxation time, the proposed MVP-MRS model can achieve a correct classification rate of 95% between BAT and WAT for in vivo mouse data implying great potentials in future longitudinal imaging of BAT and WAT. |
| 3281 | Computer #44 |
High-resolution imaging of muscular fat fraction - comparison of chemical shift-encoded imaging and T2-based imaging |
1Dept. of Translational Medicine, Medical Radiation Physics, Skåne University Hospital, Lund University, Malmö, Sweden |
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Chemical shift-encoded imaging is a quantitative method commonly used to estimate fat fraction (FF) in various body parts. However, for a reliable assessment, this technique requires short inter echo spacing which can be challenging if high spatial resolution is desirable. An alternative quantitative method, based on the difference in T2-relaxation time between fat and water, was examined and compared to the chemical shift-encoded imaging method. This T2-based technique successfully estimated FF in phantoms at high resolution and large matrix size, when the chemical shift-encoded method failed. |
| 3282 | Computer #45 |
Resolving Phase Ambiguity in Two-point Dixon Imaging Using a Projected Power Method |
1Radiology, Stanford University, Stanford, CA, United States, 2Electrical Engineering, Stanford University, Stanford, CA, United States, 3Statistics, Stanford University, Stanford, CA, United States |
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Dixon techniques offer robust water/fat separation in the presence of static field inhomogeneity. Two-point Dixon imaging with flexible echo times is desirable because of its high scan efficiency and flexibility. A major challenge in two-point Dixon imaging is how to estimate the phase error resulting from field inhomogeneity. In this work, we formulate a binary quadratic optimization and propose a fast projected power method to resolve the phase ambiguity in two-point Dixon imaging. |
| 3283 | Computer #46 |
A comprehensive approach for effective motion artifact reduction in Dixon |
1Philips Healthcare, Best, Netherlands |
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While Dixon provides superb fat suppression over large imaging volumes, motion can be a challenge in specific anatomies. This work evaluates a comprehensive approach to reduce motion artifacts in Dixon TSE and FFE sequences, combining a novel Dixon decorrelation approach, partial averaging, modulus in-phase (IP) – out-phase (OP) combinations and saturation of the physiological motion artifact sources by the means of saturation pulses and variable refocusing flip angle sweeps. We are able to show that this approach allows us to effectively remove motion artifacts improving the diagnostic quality of Dixon scans. |
| Exhibition Hall | Tuesday, May 10, 2016: 11:00 - 12:00 |
| 3284 | Computer #49 |
Developing a free-breathing dynamic contrast enhanced scan for Lung Cancer using radial ‘stack-of-stars’ technique |
1The University of New South Wales, Sydney, Australia, 2Liverpool Cancer Therapy Centre, Liverpool, Australia, 3Ingham Institute of Applied Medical Research, Liverpool, Australia, 4Prince of Wales Hospital, Randwick, Australia, 5Institute of Medical Physics, University of Sydney, Sydney, Australia, 6Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia, 7University of Wollongong, Wollongong, Australia |
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Dynamic contrast enhanced (DCE) MRI is becoming an increasingly important tool for assessing tumour response, however it's application in lung is limited by respiratory motion. We propose the use of radial acquisition technique to minimise motion by oversampling the centre of k-space albeit with reduced temporal resolution. The initial results show that the radial k-space trajectory is a suitable method for motion compensation which provided a DCE scan of sufficient image quality and temporal resolution which can be used as part of a complete free breathing lung MRI protocol. |
| 3285 | Computer #50 |
Robust in vivo DTI by Spatiotemporal Encoding |
1Chemical Physics Department, Weizmann Institute of Science, Rehovot, Israel, 2Biological Regulation Department, Weizmann Institute of Science, Rehovot, Israel |
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A recently proposed single-shot MRI methodology, SPatio-temporal ENcoding (SPEN), was evaluated for its usefulness in DTI experiments. SPEN’s direct image acquisition is not bound by k-space sampling criteria, thereby enabling the use of stronger gradients during its monitoring of the low-bandwidth dimension. This helps it to overcome image distortions arising from field inhomogeneities, eddy currents and heterogeneous chemical environments. Single-shot and interleaved DTI SPEN measurements were tested under various pre-clinical and clinical settings, and the formalism needed to extract reliable DTI maps from SPEN data was derived. Substantial advantages in terms of overcoming EPI distortions were observed. |
| 3286 | Computer #51 |
Precision and Accuracy of Multi-Echo Based T2 mapping: Fitted vs Measured B1 |
1Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 2Electrical Engineering, Vanderbilt University, Nashville, TN, United States |
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This abstract provides a simple criterion by which to determine whether refocusing pulse flip angle should be fitted or constrained to a measured B1+ map in multiple spin echo (MSE) based T2 mapping protocols. Using propagation of error theory including the Cramér-Rao lower bound, it was discovered that T2 estimate precision is improved through constraint when the signal-to-noise ratio (SNR) of the B1+ map is at least one-half the SNR of the MSE measurement. The accuracy cost of constraint is also evaluated and presented. |
| 3287 | Computer #52 |
3D Magnetic resonance fingerprinting microscopy using a vertical wide bore superconducting magnet |
1Institute of Applied Physics, University of Tsukuba, Tsukuba, Japan |
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NMR microscopy provides a variety of image contrast with a high spatial resolution. However, 3D NMR multi-parameter mapping with large matrix sizes is time consuming and practically difficult to apply to living samples. Here we introduced magnetic resonance fingerprinting (MRF) technique to 3D NMR multi-parameter microscopy, which could reduce the scan time largely. We verified the feasibility of the relaxation and proton density mapping using a vertical wide bore superconducting magnet. The 3D MRF for a grape berry provided the T1, T2, and proton density maps in the short measurement time that can be used to extract important structural information. |
| 3288 | Computer #53 |
Feasibility of 4D MRI for Assessment of Regional Hepatic Blood Flow |
1Radiology, Northwestern University, Chicago, IL, United States, 2Gastroenterology and Hepatology, Northwestern University, Chicago, IL, United States, 3Biomedical Engineering, Northwestern University, Evanston, IL, United States |
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The success of surgical and transarterial therapies for hepatocellular carcinoma relies on hepatic hemodynamics. Non-contrast 4D flow MRI can quantify hepatic blood flow at the lobar arterial and portal vein levels with a low relative error and clearly evaluate portosystemic shunts; however, segmental flow quantification remains limited. By pairing 4D flow MRI with HCC surveillance MR imaging, lobar flow per volume can also be assessed, providing valuable information for surgical planning. |
| 3289 | Computer #54 |
How to minimize motion-induced phase and magnitude modulation in diffusion-prepared sequences? |
1Zentralinstitut für Medizintechnik, Technische Universität München, Garching, Germany, 2Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany |
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Diffusion-preparation is regaining popularity recently thanks to its compatibility with any type of readout scheme. Using Bloch simulations, the current work provides understanding of the motion-induced magnitude and phase modulation of the signal obtained with diffusion-prepared sequences. When motion induces a constant phase across the voxel, dephasing signal before tipping up and rephasing it before readout should be used to remove motion-induced magnitude modulation. When the induced phase is not constant, smaller voxel sizes assist towards stabilizing both magnitude and phase of the signal. In vivo data using diffusion-prepared 3D TSE are shown supporting the observations of the Bloch simulations. |
| 3290 | Computer #55 |
Multi-site, multi-vendor comparison of T1 measurement using ISMRM/NIST system phantom |
1Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO, United States, 2University of Michigan, Ann Arbor, MI, United States, 3NorthShore University Health System, Evanston, IL, United States, 4St. Jude Children's Research Hospital, Memphis, TN, United States, 5Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 6Washington University in St. Louis, St. Louis, MO, United States, 7University of California Los Angeles, Los Angeles, CA, United States, 8University of Wisconsin, Madison, WI, United States, 9ISMRM, Berkeley, CA, United States |
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We used the ISMRM/NIST system phantom to assess variations of T1 measurements across MRI systems at 1.5 T and 3 T, to determine the repeatability and reproducibility of the T1 measurements. This study demonstrates that T1 variations from NMR-measured value are correlated site-to-site within a vendor and by position within the head coil. The deviation from the NMR-measured values is greater at 3 T than at 1.5 T. The VFA data has a larger variation than IR; B1 inhomogeneity could contribute to the larger systematic error in VFA measurements. The ISMRM/NIST system phantom is an excellent tool for evaluating multi-site MRI acquisition protocols. |
| 3291 | Computer #56 |
Detection of Metabolic Brain Activation with High Spatiotemporal Resolution T1ρ-Weighted MRI without Statistical Parametrization and without Exogenous Tracer Administration |
1Radiology Specialists of Florida, Florida Hospital, Adventist Health System, Orlando, FL, United States |
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Accurate and precise mapping of metabolically active eloquent foci in the brain, differentiating recurrent neoplasm from pseudo-progression, differentiating tumefactive demyelination from neoplasm, delineating the actual stroke penumbra, and early detection of neurodegenerative disease, all require high-resolution imaging of underlying relative brain oxygen metabolism. At the present time, however, there is no robust technique that can map brain metabolism at a high spatiotemporal resolution. This work derives and demonstrates a model for imaging of relative CMRO2 with T1ρ-weighted MRI which can be readily performed on any clinical MRI scanner with a simple pulse sequence and without the need for hardware modification. This novel approach is optimized to yield a spatial resolution of 0.2 mm3 and temporal resolution of 3.2 sec, and developed to work without exogenous tracer or contrast agent administration, blood sampling, or statistical parametrization of the image data. |
| 3292 | Computer #57 |
Repeatability of Magnetic Resonance Fingerprinting on T1 and T2 quantification with the NIST/ISMRM standardized relaxation phantom |
1Department of Biomedical Engineering, Case Western Reserve University, Clevleand, OH, United States, 2Department of Radiology, Case Western Reserve University, Clevleand, OH, United States, 3Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, CO, United States |
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In order to promote the clinical acceptance of quantitative relaxometry techniques as a valid biomarker, a fast quantitative method that can measure the relaxation parameters with high repeatability is needed. This study evaluates the repeatability of MRF with the standardized relaxometry phantom developed through collaboration between the ISMRM Ad Hoc Committee on Standards for Quantitative MR and the National Institute of Standards and Technology (NIST) over 35 consecutive days. A less than 5% variation on T1 and T2 estimations of MRF was observed in NIST standardized phantoms with a wide range of T1 and T2 values. |
| 3293 | Computer #58 |
Bloch-Siegert B1-mapping Improves Accuracy and Precision of T1 Measurements in the Breast at 3T |
1Vanderbilt, Nashville, TN, United States |
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This study evaluated the ability of Bloch-Siegert B1 mapping to improve the accuracy and precision of variable flip angle (VFA)-derived T1 measurements of the breast at 3.0 T. Accuracy was evaluated by comparing VFA T1 values to inversion recovery measurements in a cohort of 16 healthy women. A reproducibility analysis from test-retest sessions within the same cohort was used to evaluate precision. After Bloch-Siegert B1 correction, accuracy of T1 measurements in the fat and fibroglandular tissue improved and measurement variability decreased. Thus, these results suggest that Bloch-Siegert B1 mapping is an attractive correction method for quickly obtaining accurate and precise measurements of T1 values of the breast at 3.0 T. |
| 3294 | Computer #59 |
Influence of multi-compartment effects on T2 mapping using multiecho steady state imaging |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland |
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Dual and triple echo steady state (DESS and TESS) schemes have enabled rapid measurements of transverse relaxation times (T2). However, it has been shown that TESS may result in errorneous T2 values when applied to articular cartilage. Since cartilage is a multi-compartment tissue, chemical shift-related signal fluctuations in the TESS echo modes need to be considered. The purpose of this work was to investigate the accuracy of T2 quantification of multi-compartmental tissue using DESS and TESS based on computer simulations, in vitro and in vivo measurements. Results show that multi-compartment effects can significantly limit the accuracy of T2 quantification and hence require careful attention. |
| 3295 | Computer #60 |
Accelerated 3D Acquisition for Susceptibility Weighted Imaging Using Spread Spectrum Encoding and Compressive Sensing |
1Department of ECSE, Monash University, Melbourne, Australia, 2Monash Biomedical Imaging, Melbourne, Australia, 3Swinburne University of Technology/School of Software and Electrical Engineering, Melbourne, Australia |
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Spread spectrum based encoding methods have recently been investigated to spread the energy of MR signal in k-space and hence allowing for optimal incoherent sampling and hence higher performance of CS reconstruction. In this work, we extend the use of spread spectrum based encoding to 3D GRE sequence. The proposed encoding scheme can enhance the performance of multi-receive CS reconstruction at high acceleration factors and preserve resolution of small anatomical structures and preserve susceptibility contrast for Susceptibility-weighted imaging (SWI). |
| 3296 | Computer #61 |
Comparison of a novel, motion-robust MPRAGE imaging sequence with conventional MPRAGE imaging |
1Dept. of Medical Imaging, University of Arizona, Tucson, AZ, United States |
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Conventional MPRAGE imaging is an integral part of most neuroimaging protocols. We investigated a new radial fan beam ordered MPRAGE sequence for its motion robustness and compared it to conventional MPRAGE imaging on 29 patients. The radial fan beam ordering had significantly better image quality than conventional centric ordered MPRAGE when rated for motion artifacts and overall diagnostic quality by 2 trained neuroradiologists. |
| 3297 | Computer #62 |
Brain tissue pulsatility measured at 7T with high resolution and whole brain coverage |
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
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Pulsatile brain tissue motion, driven by the cardiac cycle, is important for maintaining homeostatic processes in the brain, and increased pulsatility is linked to diseases such as dementia. In this study, we demonstrate the feasibility of measuring whole brain volumetric strain with 2 mm isotropic resolution at 7T MRI in 8 healthy volunteers. Maximum volumetric strain was (2.3 ± 1.5) x 10-3, and showed considerable inter-subject and inter-slice variability that was much larger than could be explained from intrinsic measurement errors as assessed from a gel phantom. This method has potential for studying the brain pulsatility in disease. |
| 3298 | Computer #63 |
Filling the deadtime gap in zero echo time MRI: principles compared |
1Institute for Biomedical Engineering, University and ETH Zurich, Zürich, Switzerland |
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Often used for the imaging of compounds with short relaxation times, 3D center-out sequences performing broadband excitation on a ramped-up strong gradient provide very short acquisition delays and high bandwidth. In turn, data located around the k-space center is missed and needs to be recovered. Different approaches, like algebraic ZTE, WASPI or PETRA are used today. An important but still open question is how the relation of the deadtime and the T2s involved affect image quality. We show that critical situations occur for similar values of deadtime and T2, frequently encountered when imaging ultra-short-T2s in solid tissues or hardware parts. |
| 3299 | Computer #64 |
Method to Simultaneously Calibrate Flip Angles and Measure T1 of Hyperpolarized Gas during a Single Breath-hold |
1State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan Inst Phys & Math, Chinese Acad Sci, Wuhan, China, People's Republic of, 2School of Physics, Huazhong University of Science and Technology, Wuhan, China, People's Republic of |
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In hyperpolarized gas MRI, the accurate flip angle calibration and T1 measurements are important. Traditional flip angle calibration methods are time-consuming and suffer from polarization losses during T1 relaxation. In this study, we propose a method to simultaneously calibrate flip angles and measure T1 in vivo during a breath-hold time of less than 4 seconds. The so-called single-breath method is magnitude based and simple to use. We demonstrate the accuracy of this method and contrast it with traditional methods. The results of the calibration verified that it is robust and repeatable. |
| 3300 | Computer #65 |
2D Constrained Point-Spread-Function in Magnetic Resonance Spectroscopic Imaging of Prostate |
1Radiology, Brigham and Women's Hospital, Boston, MA, United States, 2Department of Biomedical Engineering, Akdeniz University, Antalya, Turkey |
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Magnetic resonance spectroscopic imaging (MRSI) technique is often plagued by signal contamination (e.g. from fat) from outside the tissue of interest, particularly near organ boundaries. The goal is to demonstrate and validate in phantoms and healthy volunteers a spatial localization technique that features localized signal excitation and therefore eliminates the need for post-processing filtering. Here we demonstrated superior PSF’s at prostate-relevant metabolic peaks for a 2D Gaussian-based PSF-Choice encoding scheme. The reduction of contamination from signals in surrounding tissue was further demonstrated in an in-vitro phantom. The feasibility of the method was demonstrated in a small group of prostate MRSI studies with normal volunteers. |
| 3301 | Computer #66 |
Performance of spin-echo MRE sequences in patients with signal-related failure of standard GRE MRE |
1Radiology, Mayo Clinic, Rochester, MN, United States, 2Royal Philips, Bangalore, India |
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Specialized spin-echo-based sequences have been developed to perform MRE in patients with short T2* where traditional MRE fails. This work demonstrates that these sequences are able to salvage such exams by improving SNR and MRE inversion confidence to the levels of successful GRE MRE exams. Additionally, the stiffnesses calculated by spin-echo and spin-echo-echo-planar acquisitions are equivalent to each other. |
| 3302 | Computer #67 |
Slice Profile Correction in 2D Magnetic Resonance Fingerprinting (MRF) |
1Radiology, Case Western Reserve University, Cleveland, OH, United States |
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The goal of this study is to characterize and improve the accuracy and repeatability of 2D MRF scans in the presence of slice profile imperfections. Slice profile imperfection causes deviation between the actual flip angles and nominal flip angles, which affects the accuracy of measured T1 and T2 values. This error can be corrected by simulating the RF excitation pulse in the dictionary. No extra scan time or post-processing time is needed once the new dictionary is simulated. The accuracy of both T1 and T2 is improved after slice profile correction. MRF also demonstrates good repeatability, with the coefficient of variance (CV) of 1.17% for T1 and 3.08% for T2. |
| 3303 | Computer #68 |
Local peripheral lung tissue microstructure quantification through CPMG relaxation rate dispersion |
1Heidelberg University Hospital, Heidelberg, Germany, 2E010 Radiology, German Cancer Research Center, Heidelberg, Germany, 3Wuerzburg University, Wuerzburg, Germany |
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Microscopically small early stage lung pathologies like emphysematous alterations of local lung tissue are usually not detectable on clinical MR images. The presented model connects defining tissue parameters for an MR imaging voxel, i.e. local alveolar radius and air-tissue ratio as well as diffusion coefficient and air-tissue susceptibility gradient, to CPMG relaxation rate dispersion over a range of inter-echo times. The model shows an excellent agreement with data from ageing hydrogel foam that mimics lung tissue. |
| 3304 | Computer #69 |
Similarity based fusion of multiple Regions of Interests for MR sequence evaluation |
1Medical Image Computing, German Cancer Research Center (DKFZ) Heidelberg, Heidelberg, Germany |
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To compare the information content of different MR sequences often regions of interests (ROI) are used. A way to avoid observer-dependencies is to use ROIs from different observer, but this leads to the question how to fuse them. We propose a new method to combine the information obtained by multiple ROIs depending on their similarity, making our method less sensitive to outlier. We evaluate our method by comparing the results obtained from the traditional merging method with the proposed algorithm. The results indicate that our method can be a valuable extension to ROI-based, multi-observer studies. |
| 3305 | Computer #70 |
A standardised clinical multicentric whole brain T2* mapping protocol at 3T |
1CATI Multicenter Neuroimaging Platform, cati-neuroimaging.com, Paris, France, 2ICM - Institut du Cerveau et de la Moelle Epinière, Paris, France, 3CEA, DSV, I2BM, NeuroSpin, UNATI, Gif-sur-Yvette, France, 4CEA, DSV, I2BM, NeuroSpin, UNIRS, Gif-sur-Yvette, France, 5Université de Strasbourg, CNRS, ICube, FTMS, Strasbourg, France, 6Neuroradiology, CHRU Roger Salengro, Lille, France, 7Université Paris-Sud, CNRS, IR4M UMR8081, Université Paris-Saclay, Orsay, France, 8INRA, UR370 QuaPA, Saint-Genès Champanelle, France |
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The purpose of this work is to report the implementation of a T2* map in multicenter neuroimaging studies. We focus on T2* because it is an endogenous biomarker for paramagnetic products like iron or melanin, which is very interesting to assess, among other diseases, Parkinson’s disease. We developed a MR sequence which meets several specific requirements. This sequence is accessible on 3 major manufacturer 3T MRI scanners and ensures good measurement accuracy at a standard millimeter isotropic resolution. This “universal” sequence allows to acquire, in a reliable and repeatable way, T2* maps of the whole brain. |
| 3306 | Computer #71 |
B0 shimming with constraints for DWI with a reduced FOV |
1Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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In this work, we investigated the application of B0 shimming with constraints, in order to accomplish an intrinsic fat suppression during 2D EPI-based pulses. For this purpose, we simulated shimming in an ROI confined to part of the abdomen. Our initial results along with the experimental tests demonstrate the possibility for such a fat suppression method. However, the residual inhomogeneity in the main excitation ROI might become very substantial, if the restriction area for fat frequencies is too narrow. |
| 3307 | Computer #72 |
SNR Optimization in ZTE Imaging |
1Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 2Vanderbilt University Institute of Imaging Sciences, Vanderbilt University, Nashville, TN, United States, 3Department of Electrical Engineering, Vanderbilt University, Nashville, TN, United States |
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Zero Echo Time (ZTE) imaging is a technique with clinical potential for imaging tissues with very short T2 relaxation times. Due to the presence of a gradient during RF excitation, there is a slice profile effect that creates artifacts in the reconstructed image. This can be corrected prior to image reconstruction, at the cost of image SNR. Increasing pulse duration increases the signal acquired while reducing it lessens this profile effect. Hence, there exists an optimal pulse duration that balances these sources of signal loss. Herein, we present an optimized approach to maximizing SNR in ZTE imaging. |
| Exhibition Hall | Tuesday, May 10, 2016: 13:30 - 14:30 |
| 3308 | Computer #25 |
3D arterial spin labeling imaging with DANTE preparation pulse |
1MR Applications and Workflow, GE Healthcare Japan Corporation, Tokyo, Japan, 2Department of Radiology, University of Fukui, Fukui, Japan, 3Radiological Center, University of Fukui Hospital, Fukui, Japan |
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DANTE preparation pulse for the arterial spin-labeling (ASL) sequence was developed to reduce the intravascular signal based on the hypothesis that DANTE could enable sufficient vascular signal suppression without any technical drawback. Phantom and human volunteer experiments were performed to evaluate the proposed method. A similar level of vascular suppression effect was observed with both MSDE and DANTE-prepared ASL sequence from phantom experiment. A signal intensity uniformity of vascular suppressed perfusion weighted images was superior with DANTE compared to MSDE. These results indicated that DANTE-preparation could be used as a vessel signal suppression method for ASL. |
| 3309 | Computer #26 |
A DOUBLE ACQUISITION FOUR-CONTRAST IMAGING APPROACH TO DELINEATE HUMAN BRAINSTEM ANATOMY IN-VIVO AT 7 TESLA |
1Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland, 2Center of Dental Medicine, University of Zurich, Zurich, Switzerland, 3Department of Neuroradiology, University Hospital Zurich, Zurich, Switzerland, 4Translational Neuromodeling Unit, Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland, 5Institute of Diagnostic and Interventional Radiology, University Hospital Zurich and University of Zurich, Zurich, Switzerland |
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The human brainstem anatomy is challenging to image in vivo on a single subject basis. The densely-packed interspersion of nuclei and white matter tracts cannot typically be imaged with an image contrast strong enough for differentiation of relevant substructures. We present an MR imaging approach at 7 Tesla that requires two high resolution MR acquisitions. From the two data sets, four image series with varying contrast weightings can be derived and used to delineate brainstem anatomy. The proposed strategy resulted in exceptionally high image quality enabling differentiation of several brainstem substructures that are hardly discernible in commonly acquired MR images. |
| 3310 | Computer #27 |
A Novel Diffusion Tensor Imaging Strategy for Delineating the Neuroanatomical Boundaries of the Amygdala |
1Pediatrics, Loma Linda University, Loma Linda, CA, United States, 2Pediatrics, University of California, Irvine, Irvine, CA, United States, 3Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, United States, 4Neurology, University of California, Irvine, Irvine, CA, United States |
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The amygdaloid complex, including the basolateral nucleus (BLA) are critically important in mediating emotional and adaptive responses to stress. However, lack of contrast between the BLA and the surrounding gray matter (GM) has hampered routine imaging. We report a novel DTI paradigm to identify the BLA in the rodent brain. We derived BLA volumes and confirmed these with histological measures. Our approach can be used to study the morphological and functional consequences of emerging neuropsychiatric diseases, both in experimental and clinical studies. |
| 3311
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Computer #28 |
Measurement of bolus arrival time and velocity in Circle of Willis using dynamic MR angiography |
1Institute of Neurology, University College London, London, United Kingdom, 2Philips Medical Systems, Philips, Tokyo, Japan, 3Centre for Medical Image Computing, University College London, London, United Kingdom, 4C.J. Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Netherlands, 5Centre for Medical Imaging, University College London, London, United Kingdom |
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The properties of the cerebral vasculature are of clinical relevance and thus of interest for investigation. Here an ASL-based 3D angiographic technique (CINEMA-STAR) is used to measure blood arrival times and blood velocities of a bolus labeled in the neck. Results are shown to be in broad agreement with existing methods. |
| 3312 | Computer #29 |
Quantitative MRI explorations of the hyaluronan-based extracellular matrix in brain tissues |
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany |
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The tissue composition of the brain can be related to different contrast sources in quantitative MRI. Particularly, myelin and iron are considered to be major sources of MRI contrast, with strong correlation to $$$T_1$$$ and $$$T_2^*$$$, respectively. However, other components, may also play a role in contrast generation. In this work, we present experiments in post-mortem human brain specimens to disentangle the potential contribution of the hyaluronan-based extracellular matrix from other contrast sources in quantitative relaxation maps. This was achieved by comparing images of digested and undigested samples that were otherwise subject to the same environmental conditions. |
| 3313 | Computer #30 |
Automatic assessment of corpus callosum malformation from structural MRI images to improve diagnosis reproducibility. |
1Neuroimaging Unit, Scientific Institute IRCCS “Eugenio Medea”, Bosisio Parini, Italy, 2Department of Computer Science, University of Verona, Verona, Italy, 3Department of Neuroradiolody, Fondazione IRCCS “Ca’ Granda” Ospedale Maggiore Policlinico, Milano, Italy, 4Department of Pediatric Radiology and Neuroradiology, Children Hospital “Vittorio Buzzi”, Milano, Italy |
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The diagnosis of brain malformations is usually based on the visual inspection of MRI images by trained neuroradiologists. The resulting procedure is therefore subjective and mainly provides a qualitative description of the detected malformations. In this study, we propose an assisted diagnosis tool (ADT) for the analysis of the corpus callosum from structural T1-weighted images. The method detects and characterizes different kind of malformations (local/diffuse, homogeneous/heterogeneous). Inter-subject reproducibility experiments showed that the agreement rate significantly improved from 67.5% to 79.3% using the proposed method. |
| 3314 | Computer #31 |
T2 mapping of ventricular cerebrospinal fluid (CSF) at 7 Tesla with comparison to 3T |
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Centre for Functional and Diagnostic Imaging and Research, Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark |
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The relaxation parameters of CSF may have potential as imaging markers in several diseases. In this work T2 mapping of CSF in the lateral ventricles and in the fourth ventricle was performed in six volunteers at 7T, with comparison to 3T. The sensitivity for B1 was assessed by comparing the T2s in both regions, with equal B1 at 3T and different B1 at 7T. T2 values were significantly lower at 7T compared to 3T. No significant difference was found between the lateral and the fourth ventricular T2s at 7T (and 3T), indicating negligible B1-sensitivity for the used T2-mapping sequences. |
| 3315 | Computer #32 |
A Generic Supervised Learning Framework for Fast Brain Extraction |
1Vanderbilt Institute in Surgery and Engineering, Vanderbilt University, Nashville, TN, United States, 2Medical Imaging Technologies, Siemens Healthcare, Princeton, NJ, United States |
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Automatic brain extraction, as a standard pre-processing step, typically suffers from a long runtime and inaccuracies caused by brain variations and limited qualities of MR images. We propose a generic supervised learning framework that builds binary classifiers to identify brain and non-brain tissues at different resolution levels, hierarchically performs voxel-wise classifications for a test subject, and refines the brain boundary using narrow-band level set technique on the classification map. The proposed method is evaluated on multiple datasets with different acquisition sequences and scanner types using uni- or multi-contrast images and shown to be fast, accurate, and robust. |
| 3316 | Computer #33 |
Reduced Distortion Artifact Whole Brain CBF Mapping using Blip-Reversed Non-Segmented 3D Echo Planar Imaging |
1Radiology & Imaging Sciences, NIH, Bethesda, MD, United States, 2Center for Neuroscience and Regenerative Medicine, Henry Jackson Foundation, Bethesda, MD, United States |
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Arterial spin labeling is typically performed with segmented k-space acquisition schemes to reduce B0 inhomogeneity related distortion. Non-segmented techniques offer the advantage of higher SNR/time allowing greater brain coverage in shorter scan times. Here we use a modified 3D EPI acquisition scheme along with pseudo-continuous arterial spin labeling to correct for B0 inhomogeneity related distortion. By employing phase encoding along opposite directions in alternating control-label pairs and with subsequent post-processing, we correct for the distortion. CBF images were compared with GM masks obtained from relatively distortion free MPRAGE images to show improved localization of the CBF maps. |
| 3317 | Computer #34 |
Imaging of thalamic substructures: T1 based approach using IR-EPI sequence at 7T |
1Imaging Institute, Cleveland Clinic Foundation, Cleveland, OH, United States |
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Accurate identification of the thalamus sub-structures is therefore important for localization of specific nuclei and for the understanding of brain function. However, sub-structures of the thalamus are so small and have intermediate signal characteristics between grey/white matter it has been difficult to identify them with conventional MR imaging technique. In this work, in-vivo T1 value at 7T are measured using fast T1 mapping technique in less than 2 min and optimized inversion time to generate optimal contrast from the thalamus. The optimized results reveal markedly improved anatomical detail of the sub-structures of the thalamus, including their detailed locations. |
| 3318 | Computer #35 |
Motion Range Grouping of Brain Regions Based on Displacement Measured with Displacement Encoding with Stimulated Echoes (DENSE) |
1MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, 2Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, United States, 3Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States, 4MR R&D Collaborations, Siemens Healthcare, Cary, NC, United States |
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In this work, we demonstrated that the DENSE technique can be used to measure and group motion of different brain regions. Preliminary results in 9 volunteers showed that the brain regions near the CSF (midbrain, pons, medulla and optic chiasm) had larger motion magnitude than regions far away (frontal lobe, occipital lobe, parietal lobe and cerebellum). DENSE enables us to investigate brain motion to a level of detail that has not been previously possible. The findings in this study may bring new insight into brain motion and provide useful information to improve potential imaging and therapy techniques. |
| 3319
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Computer #36 |
Motor Learning Induced Neuroplasticity, Revealed By fMRI-Guided Diffusion Imaging |
1e-Health Research Centre, CSIRO Health and Biosecurity, Brisbane, Australia, 2Queensland Brain Institute, The University of Queensland, Brisbane, Australia, 3School of Psychology, The University of Queensland, Brisbane, Australia |
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Detecting neuroplasticity requires highly sensitive measurements that may be outside the bounds of standard parcellation-seeded tractography. Earlier attempts to measure neuroplasticity induced by motor learning have utilised voxelwise analyses. Such analyses are reliant on precise registration, can have low statistical power, and provide little certainty as to the functional relevance of areas of detected change. We have measured motor-learning-induced neuroplasticity along corticomotor and thalamocortical tracts using fMRI-seeded diffusion-MRI, finding that changes uniquely occur in the corticomotor tract. Unlike previous analyses, we reveal that these changes occur throughout the corticomotor tract, not just near the grey-/white-matter interface. |
| 3320 | Computer #37 |
Cerebral Tissue Characterization by Magnetic Resonance Elastography and Arterial Spin Labeling |
1Physics, Humboldt University Berlin, Berlin, Germany, 2Radiology, Charité - University Medicine Berlin, Berlin, Germany, 3Berlin Center for Advanced Neuroimaging, Berlin, Germany |
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Two imaging modalities, magnetic resonance elastography (MRE) and arterial spin labeling (ASL), were used to compare mechanical properties of brain tissue with regional perfusion across subcortical brain regions. An inverse correlation of stiffness (|G*|) and average perfusion (CBF) was observed in deep gray matter when accounting for structurally and functionally distinct areas. In the |G*|-CBF space, globus pallidus, hippocampus, thalamus and amygdala clearly clustered from putamen and nucleus accumbens highlighting their anatomical differences in network density and vasculature. Differences in the microstructure between the striatum and other analyzed regions are not apparent by MRE or ASL alone. |
| 3321 | Computer #38 |
A New High-Resolution Perfusion-Weighted Imaging Technique without exogenous tracer and Its Quantitative Model |
1Electrical Engineering, KAIST, Daejeon, Korea, Republic of |
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The proposed method is based on the perfusion model of intravoxel incoherent motion (IVIM), which assumes that perfusion is a microcirculation of blood in the capillary network. The method introduces two-types of bi-polar gradients in a radial spin-echo sequence, a new ordering of bi-polar gradients for isotropic perfusion weighting, and signal models for quantitative analysis of perfusion. To verify the proposed method, in-vivo imaging in 3 T MRI was performed, and the proposed method offers the high-resolution quantitative perfusion map. |
| 3322 | Computer #39 |
Insula Cortex Parcellation with Q-ball Residual Bootstrap Tractography Algorithm |
1Neurology, Memory Aging Center, UCSF, San Francisco, CA, United States, 2Radiology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy, 3Neurology, UCSF, San Francisco, CA, United States, 4Bioengineering Graduate Group, Berkeley, CA, United States, 5Radiology and Biomedical Imaging, San Francisco, CA, United States, 6Brain and Behavioral Sciences, Pavia, Italy |
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The insula cortex is involved in different functions, however its cortical connections have not yet been extensively explored. Whole brain tractography with Q-ball residual bootstrap algorithm was performed in 17 controls. Insula and the cortex regions were used as ending-ROIs. We found structural connections between the insula and 22 cortical regions for each hemisphere. After registered the images to the MNI space, the parcellation of the insula was obtained based on the ending-tract connected with each of the cortex region. Availability of a template atlas of insular structural connectivity would contribute to a better understanding of its multiple functions. |
| 3323 | Computer #40 |
An Atlas Pre-selection Method for Multi-atlas Based Brain Segmentation |
1Department of Electronic and Information Engineering, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen, China, People's Republic of |
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This study proposed 4L and LV-based methods to improve the brain segmentation accuracy and eddiciency of multi-atlas brain segmentation. The atlas database contains T1 images of brain from 77 subjects. These two methods were adopted to calculate the Dice between the target image and each atlas. We compared the proposed methods with MI-based method and randomly selected method for geriatric, adult and pediatric populations. The segmentation accuracy was evaluated by Dice and the results show that the accuracy of 4L and LV-based methods has great improvement. In addition, the proposed pre-selection is more efficient. |
| 3324 | Computer #41 |
Characterizing Cerebral Arterial Pulsatility and Flow Waveforms from the Proximal Internal Carotid Artery to Distal Middle Cerebral Artery in Adult Volunteers Using 4D Flow MRI |
1Department of Radiology, Northwestern University, Chicago, IL, United States, 2Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States, 3Department of Mechanical Engineering, University of Toronto, Toronto, ON, Canada |
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Characterization of cerebral arterial flow waveforms in healthy subjects can help establish a comparison baseline in studies of cerebrovascular disease and provide key inputs for computational fluid dynamic studies. The purpose of this study was to quantitatively characterize cerebral arterial waveforms in healthy adult subjects by extracting arterial pulsatility and flow waveforms along the ICA and MCA using 4D flow MRI. Our findings demonstrated no significant changes in arterial pulsatility from proximal ICA to distal MCA, although a decreasing trend was observed from the proximal to distal carotid siphon in young adults. |
| 3325 | Computer #42 |
Effect of window length on quasi-periodic pattern template correlation with fMRI data |
1Neuroscience Program, Emory University, Atlanta, GA, United States, 2School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan, 3Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States, 4Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, United States |
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Quasi-periodic patterns that include alternation between the default mode and task positive networks are known to occur in humans and their templates can be acquired using a previously developed QPP-finding algorithm. The algorithm, however, relies on a user-specified window length for the QPP, the optimal size of which is not known. We apply the QPP algorithm on rsfMRI scans using varying window lengths and compare properties of observed QPP templates. Our results indicate an optimal window length adequately depicting QPP occurrences in human functional data. This will allow us to accurately characterize QPPs and study how they may be affecting functional connectivity measurements and brain function. |
| 3326 | Computer #43 |
Coupled fitting of T2 relaxometry and multi-shell diffusion weighted image data |
1Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 2Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, United Kingdom, 3UCL Institute of Neurology, University College London, London, United Kingdom |
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This work combines information from acquisitions of diffusion-weighted and T2 relaxometry data to allow improvements in separating out multiple compartments. This is particularly useful when fitting a multi-compartment diffusion model or a multi-component T2 relaxometry model. Work of this type might allow improved fitting of multi-modal derived parameters such as the g-ratio. |
| 3327 | Computer #44 |
Regional variation of total sodium concentration in the healthy human brain |
1Translational Imaging Group, Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 2NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom, 3Department of Radiology, University of Cambridge, Cambridge, United Kingdom, 4Brain Repair & Rehabilitation, UCL Institute of Neurology, University College London, London, United Kingdom, 5Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy |
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Non-invasive measurement of in vivo total sodium concentration (TSC) has been possible due to advances in sodium MRI at clinical field strengths. Changes in white and grey matter concentrations have been reported in a number of different diseases like Multiple Sclerosis. However, the presence of regional differences in normal healthy brain TSC has not been yet investigated. Here we use Geodesic Information Flow technique for computing per subject brain parcellations to allow differentiation of these areas and subsequently characterization of regional TSC in healthy controls. |
| 3328 | Computer #45 |
Effect of Gabapentin Administration on GABA and BOLD Signal in Visual Cortex of Healthy Men and Women |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States, 3Obstetrics and Gynecology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States, 4Penn Center for the Study of Sex and Gender in Health, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States, 5Penn Center for Women’s Behavioral Wellness, Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States |
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We explored the potential for sex differences in brain Gamma-aminobutyric acid (GABA), glutamate (Glut) and neural response to an acute dose of gabapentin by using proton magnetic resonance spectroscopy (1H-MRS) followed by functional magnetic resonance imaging (fMRI) at 7T. |
| 3329
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Computer #46 |
Brain volume changes during hypercapnia: Volume Reactivity |
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
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Here we investigate brain volume changes upon a vasodilatory hypercapnic stimulus as a potential alternative to obtain cerebral tissue reactivity information. Using relatively standard 3D T1-weighted scans (MP-RAGE) and segmentation software we show significant volume changes (in all subjects) in subcortical deep gray matter areas which were paralleled by decreases in ventricular volume. This approach (volume reactivity) could yield novel insights on cerebral tissue reactivity in healthy and disease and be a potential alternative in cases where BOLD or ASL CVR interpretation can be ambiguous. |
| 3330 | Computer #47 |
The IVIM signal: a combination of two vascular pools |
1CEA Saclay/Neurospin, Gif-sur-Yvette, France, 2INRIA Saclay, Palaiseau, France, 3Beckman Institute of Advanced Science and Technology, Urbana, IL, United States |
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IntraVoxel Incoherent Motion (IVIM) imaging allows to extract perfusion parameters from a series of diffusion weighted images. We show that the standard mono-exponential model used to describe the IVIM signal can be improved by switching to a bi-exponential model. Multiple diffusion time rat brain images were acquired at 7T and compared to numerical simulations of blood flow through the microvascular network. Our results demonstrate that the bi-exponential model better describes the data especially at short diffusion times and suggest that the IVIM signal comprises the contributions from two different vascular pools: small vessels (capillaries) and medium sized-vessels. |
| 3331 | Computer #48 |
REPLICABILITY OF CEREBRAL PERFUSION WITH DIFFERENT ARTERIAL SPIN LABELLING METHODS |
1Department of Diagnostic and Interventional Imaging, KK WOMEN'S AND CHILDREN'S HOSPITAL, SINGAPORE, Singapore, 2Singapore Bio-Imaging Consortium, A*STAR, SINGAPORE, Singapore, 3Siemens Healthcare, Regional Headquarter, SINGAPORE, Singapore |
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We compared 3 versions of Arterial Spin Labelling (ASL) available ( single-TI 3D-PASL, multi-TI 3D-PASL and 2D-pCASL) on 3T Siemens MRI scanner Skyra in 10 normal healthy adults with normal body mass index (BMI) at 3 different time points (baseline, 1 week later, 2 to 3 month later). There was good replicability of all 3 ASL techniques (correlation coefficients range from 0.55 to 0.77). Values acquired with these ASL techniques agree with the published normal range of cerebral blood flow values in adults. There is no significant difference in the CBF obtained with single-TI 3D-PASL, multi-TI 3D-PASL and 2D-pCASL. |
| Exhibition Hall | Tuesday, May 10, 2016: 13:30 - 14:30 |
| 3332 | Computer #1 |
In-vivo Simultaneous Brain 18F FDG PET Imaging and 13C MR Spectroscopy: Initial Experience |
1King's College London, London, United Kingdom, 2Siemens Healthcare, Frimley, United Kingdom, 3Rapid Biomedical, Wuerzburg, Germany, 4Siemens Healthcare, Erlangen, Germany, 5University Duisburg-Essen, Essen, Germany |
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We investigate the feasibility of in-vivo simultaneous brain 18F FDG PET imaging and 13C MR spectroscopy using a dedicated dual-tuned 1H-13C coil with low PET attenuation. Simultaneous in-vivo 18F FDG PET imaging and 13C unlocalized natural abundance MR spectroscopy were performed on three patients. Initial results show the technical feasibility of the simultaneous in-vivo measurement with good spectral and PET image quality. |
| 3333 | Computer #2 |
Optimizing dynamic MRI of the orbit during eye movement for clinical use: patient aptitude considerations. |
1Department of Neuroradiology, University Hospital Zurich, Zurich, Switzerland, 2Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland, 3ICT, University Hospital Zurich, Zurich, Switzerland, 4Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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To improve neuro-ophthalmologic surgery, biomechanical inside about the pathophysiological dynamic of eye movements is needed. High spatiotemporal resolution dynamic MR imaging of the orbit during eye movement shall provide such information. To enable clinical use, the acquisition design needs to accommodate limited patient capabilities to perform repetitive eye movement accurately. |
| 3334 | Computer #3 |
Highly-Accelerated, Self-Calibrated Stack-of-Spirals Arterial Spin Labeling Using 3D SPIRiT Reconstruction |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Neurology, University of Pennsylvania, Philadelphia, PA, United States, 3Hangzhou Normal University, Hangzhou, Zhejiang, China, People's Republic of |
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3D coverage of the whole brain by using RARE-refocused stack-of-2D-spirals often suffers from low temporal/spatial resolution due to the long spiral readout or long echo train. In this work we present a method that allows whole-brain coverage at 3 mm isotropic spatial resolution with one- or two-segment, accelerated acquisitions in both partition and spiral directions. The technique was applied in conjunction with background-suppressed pCASL, resulting in improved temporal/spatial resolution for quantification of cerebral blood flow. |
| 3335 | Computer #4 |
Quantifying cerebral blood flow with distortion-corrected pseudo-continuous arterial spin labeling |
1Radiology, University of Washington, Seattle, WA, United States |
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Cerebral blood flow (CBF) may be quantified using pseudo-continuous arterial spin labeling (pCASL), but pCASL suffers from image distortion due to its long echo planar imaging (EPI) readout. Phase labeling for additional coordinate encoding (PLACE) is employed here to remove distortion. EPI images and pCASL subtraction images show improved spatial accuracy when compared to a T1-weighted, anatomical reference image. This results in improved accuracy in CBF quantification, which could potentially improve the assessment of disease-specific patterns indicated by regional CBF abnormalities. |
| 3336 | Computer #5 |
Conductivity Determination of Deep Gray Matter Nuclei Utilizing Susceptibility-Based Delineation |
1Philips Research Europe, Hamburg, Germany |
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Deep gray matter nuclei (DGMN) in the human brain play an important role for numerous diseases like Alzheimer’s disease. Thus, the characterization of DGMN in the framework of multiple MR-based physiologic parameters (like magnetic susceptibility or electric conductivity) is expected to be helpful for understanding these diseases. This study investigates – to the best of our knowledge, for the first time - the electric conductivity of DGMN in healthy volunteers, reflecting the electrolyte content of these nuclei. Conductivity determination is boosted by utilizing geometry information obtained from susceptibility maps during conductivity reconstruction. |
| 3337 | Computer #6 |
Optimization of the tagging region profile in super selective arterial spin labeling |
1MR Research China, GE Healthcare, Beijing, China, People's Republic of |
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This work investigates the gradient design scheme in ssASL labeling train to improve the labeling profile. Both numerical approach and MR studies were performed. Refocused labeling and unrefocused control could generate flatter labeling region compared to currently adopted method. This was verified in in-vivo MR study. |
| 3338 | Computer #7 |
Acute effects of caffeine on grey matter haemodynamics |
1CUBRIC, Cardiff University, Cardiff, United Kingdom, 2Department of Anesthesia and Intensive Care Medicine, Cardiff University, Cardiff, United Kingdom |
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The acute effects of caffeine on haemodynamics are not well characterized across the brain with MRI. We aim at measuring these in a double-blind, crossover, placebo-controlled study on sixteen healthy, moderate caffeine consumers using mTI PASL acquisitions and a two-compartment ASL model. Results show spatial variations in the CBF and TAT response across grey matter at different levels of resolution (grey matter, ROI and voxel), with the latter presenting mixed directions. Moreover we demonstrate that great attention must be paid to physiological assumptions when modelling ASL data to estimate CBF in studies on drugs that affect brain haemodynamics. |
| 3339 | Computer #8 |
Blood flow velocity and pulsatility in perforating arteries of cerebral white matter during hypercapnia |
1Radiology, UMCU, Utrecht, Netherlands |
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An increased blood flow pulsatility index in large cerebral arteries is a prognostic factor in stroke and has been linked to small vessel disease. Along with increased pulsatility, these patients show decreased hypercapnia induced cerebrovascular reactivity. We hypothesize that dilated vessels lose their ability to stretch and passively dampen the pulse pressure wave. The aim of this study was to shed light on how autoregulation influences the damping of the pulse pressure wave in small vessels. Our approach was to measure blood flow velocity and pulsatility changes in the perforating arteries of the white matter, during a hypercapnic breathing challenge. |
| 3340 | Computer #9 |
Pushing the limits of speed and accuracy for 7T GABA MR spectroscopy to reveal GABA level fluctuations in resting brain |
1Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
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By maximizing acquisition volume, using efficient semi LASER detection with editing and macro molecular nulling, GABA can be detected at high SNR within 3 minutes. GABA concentrations were measured in the visual cortex and in a phantom containing a known concentration of GABA. A bootstrapping method was used to determine the accuracy. The results indicate that the stability and fitting accuracy of the method is sufficient to detect concentration changes of GABA higher than 3% within a short scan time of less than 3 minutes. In resting state, GABA fluctuations up to 30% are found in in-vivo brain measurements. |
| 3341 | Computer #10 |
Metabolic changes in the activated human visual cortex during mild hypoxia |
1CMRR, Department of Radiology, University of Minnesota, Minneapolis, MN, United States, 2Department of Physics, University of Sao Paulo, Ribeirao Preto, Brazil, 3School of Kinesiology, University of Minnesota, Minneapolis, MN, United States, 4Central European Institute of Technology, Masaryk University, Brno, Czech Republic, 5Department of Medicine, University of Minnesota, Minneapolis, MN, United States, 6Division of Biostatistics, University of Minnesota, Minneapolis, MN, United States |
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Previous fMRI studies have demonstrated reduced evoked vascular responses during mild hypoxia, which might indicate smaller neuronal recruitment during activation. Here we used fMRS at 7T to quantify the effects of mild hypoxia on stimulus-induced metabolic changes during visual stimulation. Our preliminary findings obtained on 6 healthy volunteers show that mild hypoxia does not result in detectable differences of functional metabolic changes as compared to normoxia, consistent with similar functional energy demands in both conditions. Together with previous fMRI findings, our results suggest that mild hypoxia alters the neurovascular coupling, but does not result in smaller neuronal recruitment during activation. |
| 3342 | Computer #11 |
Quantification and normalization of Cerebral Blood Flow in rat brain using Pseudo-continuous Arterial Spin Labeling with phase-contrast-based flow measurement at 7 Tesla. |
1Singapore Bioimaging Consortium, Singapore, Singapore |
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pCASL is a modified form of CASL where a short train of RF pulses reproduces CASL. pCASL sequence uses flow driven adiabatic pulses to invert the spin. The labeling efficiency of the pCASL sequence has a dependency on the velocity of the blood at the labeling. Phase contrast MRI (PCMRI) was used to measure the velocity of the blood at the labeling plane and to normalize the CBF value. In this study, we tested pCASL and PCMRI acquisition on a cohort of control rats vs. hyperglycemic rats and documented effect of varied labeling efficiency. |
| 3343 | Computer #12 |
High field imaging of large-scale neurotransmitter networks: concepts, graph theoretical metrics, and preliminary results |
1Departments of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, Netherlands, 2School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands, 3Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, Netherlands, 4Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands, 5Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 6Epilepsy Center Kempenhaeghe, Heeze, Netherlands, 7Department of Neurology, Maastricht University Medical Center, Maastricht, Netherlands |
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Many studies are performed to assess structural or functional brain connectivity. However, these studies do not provide direct information on neurochemical imbalances, which underlie abnormal neuronal functioning. In this study, the concept of ‘large-scale neurotransmitter networks’ is proposed. The spatial neurotransmitter network was assessed in fifteen healthy participants who underwent 7T MR spectroscopic imaging. The average glutamate and GABA concentrations were computed in thirty brain regions, which were considered connected if the concentrations showed a significant correlation over all thirty participants. Both glutamate and GABA networks showed small-world characteristics, but further exploration of this concept is currently ongoing. |
| 3344 | Computer #13 |
Cerebral Arterial Inflow and Venous Outflow: Flow Discrepancy and Relation to Cardiac Outflow in Children and Adult Volunteers |
1Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States, 2Department of Radiology, Northwestern University, Chicago, IL, United States, 3Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States, 4Rush Medical College, Chicago, IL, United States |
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Abnormal cerebral venous outflow patterns may cause severe cerebrovascular disease. We aim to investigate the relationships between cerebral venous outflow and arterial inflow and between cerebral arterial inflow and cardiac outflow in adult and children volunteers using 4D flow and 2D phase-contrast MRI. The results demonstrate significant discrepancies between cerebra arterial inflow and venous outflow with larger discrepancies in children than adults. Additionally, we observed a significantly association of cerebral and cardiac flow parameters with age. |
| 3345 | Computer #14 |
A Potential Global Brain Network Identified Using Resting State Arterial Spin Labeling |
1Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States, 2Computer Science, State University of New York at Binghamton, Binghamton, NY, United States |
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ASL global signal fluctuations, uniformly correlated across gray matter, may reflect globally correlated neural activity that would suggest a global resting network. However, physiological noise, such as cardiac and respiratory motion, could potentially contribute to the global signal fluctuations. Our results indicate that the systemic noise does not contribute to the ASL global signal fluctuation significantly. Global signal fluctuations are the dominant resting fluctuations of the ASL signal, suggesting a separate globally correlated resting state network in addition to those region-specific resting state networks. |
| 3346 | Computer #15 |
High Resolution quantitative T1 mapping under graded hyperoxia at 7T |
1Radiology, UMC Utrecht, Utrecht, Netherlands, 2Radiotherapy, UMC Utrecht, Utrecht, Netherlands, 3UMC Utrecht, Utrecht, Netherlands, 4Utrecht, Netherlands |
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We use native T1 (qT1) mapping to measure tissue T1 changes in response to precisely targeted, graded hyperoxic respiratory challenges at 7T. |
| 3347 | Computer #16 |
Quantification of the effect of head-down tilt posture on intracranial condition using MRI |
1Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan, 2Department of Radiology, Shiga University of Medical Science Hospital, Otsu, Japan, 3Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan, 4Department of Radiology, University of Miami, Miami, FL, United States, 5Department of Radiology, Kanazawa University, Kanazawa, Japan |
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To quantify the effect of posture on intracranial condition, we assessed intracranial volume change (ΔICVC), pressure gradient (ΔPG), intracranial compliance index (ICCI), and apparent diffusion coefficient (ADC) change of the brain during the cardiac cycle (ΔADC) in head-down tilt (HDT) and horizontal supine positions. ΔPG was significantly increased on HDT compared with that in the horizontal supine position because of the intracranial pressure compensatory mechanism. However, there were no significant differences in other parameters between postures. ΔPG analysis in the HDT and horizontal supine positions makes it possible to evaluate intracranial conditions concerning the intracranial pressure compensatory faculty. |
| 3348 | Computer #17 |
Dexamethasone Effects on Brain Function in Normal Healthy Subjects: a Magnetic Resonance Imaging Approach |
1A*STAR-NUS Clinical Imaging Research Centre, Singapore, Singapore, 2National University Hospital, Singapore, Singapore |
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Dexamethasone (DEX) is commonly used at varying dosages to treat a range of diseases such as altitude sickness and leukemia. Current reports of neuropsychiatric and cognitive effects after DEX administration lack determination of the pathophysiological mechanism of such effects. This work aims to investigate the neurotoxic effects of DEX in healthy subjects by collecting MR structural and 1H spectroscopy data. Analysis showed a significant reduction in brain volume structures and hippocampal GABA/water (p < 0.02) ratio from start to end of DEX administration, which is recovered after a washout period. |
| 3349 | Computer #18 |
High-Speed Whole-Brain Oximetry with a Golden-Angle Radial Imaging Sequence |
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States |
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The OxFlow imaging approach allows simultaneous quantification of whole-brain venous oxygen saturation and total cerebral blood flow for the cerebral metabolic rate of oxygen. However, the current Cartesian rendition of the sequence is not ideal as the achievable temporal resolution is limited and needs to be chosen upfront. Here, we designed a golden-angle radial (GAR) encoding sequence that yields an effective temporal resolution of 1.29s and evaluated it in six subjects who underwent a paradigm of repeated breath-holds. Good agreement exists between the two methods but GAR provided superior SNR and better delineation of the temporal dynamics during the stimulus. |
| 3350 | Computer #19 |
Cerebrovascular reactivity measured with quantitative susceptibility mapping and TRUST MRI under hypercapnia |
1Radiology, New York University School of Medicine, New York, NY, United States, 2Radiology, Johns Hopkins University, Baltimore, MD, United States |
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Cerebrovascular reactivity (CVR) measures the capacity of regulation of blood flow in response to vasoactive stimuli (e.g., CO2) via changes in cerebral arterial resistance. CVR is responsible for maintaining optimal blood flow to meet the energy demand by neurovascular coupling during neuronal tasks. The defected CVR can cause transient states of inefficient blood delivery during neural activity leading to subsequent neurodysfunction and degeneration. CVR is commonly measured with mild hypercapnia (5%CO2) ASL or BOLD MRI. The purpose of this study was to test the feasibility to measure CVR using hypercapnia MRI with quantitative susceptibility mapping (QSM) and T2-relaxation-under-spin-tagging (TRUST) techniques. |
| 3351 | Computer #20 |
Functional MRS at 7T and long TE |
1CMRR, Department of Radiology, University of Minnesota, Minneapolis, MN, United States, 2Central European Institute of Technology, Masaryk University, Brno, Czech Republic, 3Department of Medicine, University of Minnesota, Minneapolis, MN, United States, 4Department of Physics, University of Sao Paolo, Ribeirao Preto, Brazil, 5Division of Biostatistics, University of Minnesota, Minneapolis, MN, United States |
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With the goal of evaluating whether relaxation influences functional MRS (fMRS) results, we conducted fMRS experiments at 7T during visual stimulation using semi-LASER at 7T at long TE and short TR. The functional concentration changes of lactate (37%±6%) and glutamate (~5%±1%) observed here were consistent with previous results obtained at long TR and ultra-short TE. Small functional changes in signal intensity of NAA and Cr were also found, consistent with small changes in relaxations of those metabolites during visual stimulation. |
| 3352 | Computer #21 |
T2 measurements during hyperoxia in the lateral ventricles and peripheral CSF |
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Centre for Functional and Diagnostic Imaging and Research, Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark |
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The oxygen tension in CSF and tissue is coupled, but may be easier to measure in CSF. This work investigated the effect of O2 administration on the T2 of CSF. In five subjects, T2s were mapped in the lateral ventricles and the peripheral CSF during administration of a hyperoxic gas mixture (end-tidal O2 level: 500mmHg). In the lateral ventricles no T2 change was observed, in the periphery a significant T2 reduction was found under O2 administration (T2=1.54s) compared to baseline (T2=1.61s), showing the feasibility to use CSF relaxation parameter mapping to detect oxygen tension changes. |
| 3353 | Computer #22 |
Placebo modulation of brain activity associated with orthodontic pain: a single-blind fMRI Study |
1Department of Radiology, Huaxi MR Research Center, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 2West China Hospital of stomatology, Sichuan University, Chengdu, China, People's Republic of |
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To investigate the neural mechanism of placebo effects in orthodontic pain, we conducted a fMRI study where twenty-three volunteers, under orthodontic pain induced by separators, were scanned without placebos and followed by another scan with placebos a month later. During both scans, participants were instructed to perform a bite (with maximum strength)/no-bite block design fMRI task. Compared with the non-placebo condition, the participants with placebos demonstrated significant reduced brain activities in multiple regions, including precentral gyrus, superior frontal gyrus, superior parietal lobule and supramarginal gyrus. This study may provide new insights into the neural mechanism of analgesia by placebo. |
| 3354 | Computer #23 |
Spatially inhomogeneous CBV-CBF relationship across human visual cortex |
1Department of Radiology, Michigan State University, East Lansing, MI, United States |
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Cerebral blood volume (CBV) is related with cerebral blood flow (CBF), and knowing this relationship may play an important role in quantitative BOLD-fMRI studies. A recent MRI study reports a varied CBV-CBF relationship both spatially and with sex. This study investigated the behaviors of CBV and CBF across the visual cortex at both rest and activation states, and the analysis showed a spatially inhomogeneous CBV-CBF relationship across the visual cortex. |
| 3355 | Computer #24 |
To Investigate the Regional Functional Connectivity of DMN Alterations in Hypercapnia |
1Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan, 2Department of Computer Science and Information Engineering, National Cheng-Kung University, Tainan, Taiwan, 3Institute of Medical Informatics, National Cheng-Kung University, Tainan, Taiwan, 4Graduate Institute of Oncology, National Taiwan University, Taipei, Taiwan, 5Department of Eletrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, 6Department of Eletrical Engineering, National Taiwan University, Taipei, Taiwan, 7Department of Radiology, China Medical University Hospital, Taichung, Taiwan |
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To investigate the relationships among regional activity of DMN in different hypercapnia affect using resting-state functional magnetic resonance imaging (rs-fMRI). 10 healthy males were enrolled in this study. A high-resolution T1WI image and BOLD-EPI were performed by a 3 Tesla MR scanner. The CO2 gas mixture (air, 3%, 5% and 7%) was given at the different hypercanpic for each experiment. Our results show that the functional connectivity of DMN is changed in hypercapnia. FC is slight change in 3% CO2 fractions and gradual reduction as the CO2 fraction increases. |
| Exhibition Hall | Tuesday, May 10, 2016: 13:30 - 14:30 |
| 3356 | Computer #49 |
Hybrid Diffusion Imaging to Detect Acute White Matter Injury after Mild TBI |
1Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States, 2Department of Psychological and Brain Sciences, Dartmouth College, Dartmouth, NH, United States, 3Department of Psychiatry, Dartmouth Hitchcock Medical Center and New Hampshire Hospital, Lebanon, NH, United States, 4Department of Psychiatry, Indian University School of medicine, Indianapolis, IN, United States |
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In the present study we used multi-shell Hybrid Diffusion Imaging (HYDI) to study white matter changes in the acute stage of mild traumatic brain injury (mTBI). Nineteen mTBI patients and 23 trauma-controlled subjects were recruited and studied within 1 month of injury. Non-parametric diffusion analysis, q-space imaging as well as parametric analyses including conventional DTI and novel neurite orientation dispersion and density imaging (NODDI) were used to analyze the HYDI data. Only intra-axonal volume fraction of the NODDI model showed significant and diffuse decrease in white matter of the mTBI patients. |
| 3357 | Computer #50 |
Aberrant Structural and Functional Networks Associated with Comorbidity of Depression and Mild Traumatic Brain Injury |
1Henry M Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States, 2National Intrepid Center of Excellence, Bethesda, MD, United States |
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Comorbid depression and PTSD are common among military traumatic brain injury population. This study assess brain structural and functional networks affected in military service members diagnosed with mild TBI. |
| 3358 | Computer #51 |
Acute white matter changes within 24 hours and at 8 days following sport-related concussion: a diffusion tensor and diffusion kurtosis imaging study |
1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 2Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States, 3Neurology, Medical College of Wisconsin, Milwaukee, WI, United States |
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The aim of this study was to characterize acute white matter changes within 24 hours and at 8 days following sport-related concussion in a group of young adult athletes. Both diffusion tensor and diffusion kurtosis tensor parameters were compared between concussed athletes and controls. The concussed group demonstrated widespread decrease in mean, axial, and radial diffusivity and increased axial kurtosis compared to the controls. Although diffusion effects became more extensive between the two time points, clinical measure differences between groups were nonsignificant at the 8-day follow-up. These findings may have significant implications for the clinical management of sport-related concussions. |
| 3359
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Computer #52 |
Finding biomarkers of cognitive decline in active professional fighters with multimodal MRI and exploring the longitudinal relationship of these biomarkers with cognitive decline |
1Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States |
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Several cross-sectional MRI studies have shown structural differences in professional fighters but there has been no results reported in longitudinal studies of such active fighters. The professional fighters brain health study (PFBHS) is a longitudinal study of active professional fighters with age-matched healthy controls using multimodal MRI methods. In this study, we show that the features/biomarkers predicting cognitive decline at baseline are sensitive and specific over time in our cohort of longitudinal active fighters. Our study opens a new window to predict and monitor cognitive decline in patients with traumatic brain injuries. |
| 3360
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Computer #53 |
Robust fiber crossing invariant analysis of white matter microstructure in acute mild traumatic brain injury |
1Department of Rehabilitation and Brain Trauma, Turku University Hospital, Turku, Finland, 2Department of Clinical Medicine, University of Turku, Turku, Finland, 3iMinds-Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium, 4Department of Radiology, Turku University Hospital, Turku, Finland |
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We used a robust diffusion MRI approach to analyze global microstructural abnormalities in mild traumatic brain injury (mTBI) without confounding effects of complex fiber configurations. Microstructural properties of white matter skeleton were investigated, but only voxels with a single fiber orientation detected with constrained spherical deconvolution were included. In addition, whole-brain fiber tractograms were investigated. We studied 107 patients with mTBI and 28 age-matched control subjects. We found that fractional anisotropy was significantly decreased in mTBI, while mean diffusivity and radial diffusivity were increased. These differences were more significant when the analysis was restricted to single-fiber voxels. |
| 3361 | Computer #54 |
Gray Matter Alterations Using Voxel-Based Morphometry May Not Reflect Changes In Morphometry: A Study of Mild Traumatic Brain Injury |
1Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, 3Department of Radiology, The Affiliated Ningbo Medical Treatment Center Lihuili Hospital of Ningbo University, Zhejiang, China, People's Republic of, 4Department of Rehabilitation Medicine, New York University Langone Medical Center, New York, NY, United States |
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Voxel-based morphometry (VBM) analysis has been used to detect morphometric changes of the GM after mild traumatic brain injury (mTBI). Spatially normalized and modulated GM density from VBM analysis is typically interpreted as GM volume. VBM is, however, sensitive not only to changes in volume but to variations in T1 relaxation. In this study, we investigated alterations in GM density using simulated images and VBM followed by an in vivo study of cortical GM morphometry using GM density and cortical thickness in mTBI patients and matched controls. |
| 3362 | Computer #55 |
Bi-directional changes in fractional anisotropy are associated with altered fiber tracts after experimental TBI |
1Neurosurgery, UCLA, Los Angeles, CA, United States, 2Neurosurgery, University of California at Los Angeles, Los Angeles, CA, United States, 3Engineering, Radiology, & Ophthalmology, University of Southern California, Los Angeles, CA, United States |
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Diffusion tensor imaging (DTI) is now widely used in both clinical and experimental research for studying pathology related to traumatic brain injury. However, studies report a wide range of DTI indices that are not easily ascribed to post-injury time-point, injury severity or developmental stage. In order to provide further information to help interpret these often complex changes we obtained DTI data before and after TBI using the well-known, clinically relevant rodent controlled cortical impact (CCI) model of TBI. In addition to the expected decreases in fractional anisotropy (FA) around the primary injury site which were associated with myelin breakdown and neurofilament loss, we found significant increases in FA within subcortical regions that were not associated with gliosis or fiber tract degeneration. Fiber tract density was decreased in regions of lowered FA but significantly increased only in subcortical regions associated with increased FA. High FA region seeded for tractography yielded significantly increased fiber length compared to pre-injury. These data provide additional insight into the interpretation of DTI indices following TBI. |
| 3363 | Computer #56 |
White Matter Integrity In Acute Mild Traumatic Brain Injury: A Diffusion Kurtosis MRI Study |
1Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, 3Department of Rehabilitation Medicine, New York University Langone Medical Center, New York, NY, United States |
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Mild traumatic brain injury (mTBI) is a growing public health problem. Most patients recover quickly, but some patients may suffer from serious symptoms. In this study, we investigated white matter (WM) changes in mTBI in terms of compartment specific WM tract integrity (WMTI) metrics derived from diffusion kurtosis imaging (DKI), such as intra-axonal diffusivity (Daxon), extra-axonal axial and radial diffusivities (De,a and De,r), and axonal water fraction (AWF). The observed decreases in Daxon and De,a suggest that increased restrictions along the axons, both inside and outside, such as possible axonal beading, could occur acutely after injury. |
| 3364 | Computer #57 |
Diffusion tensor imaging analysis to assess stem cell therapy efficacy in traumatic brain injury |
1Center for Interdisciplinary MR, National High Magnetic Field Laboratory, Tallahassee, FL, United States, 2Chemical & Biomedical Engineering, Florida State University, Tallahassee, FL, United States, 3Biomedical Sciences and Program in Neuroscience, Florida State University, Tallahassee, FL, United States |
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Traumatic Brain Injury (TBI) interferes with the functionality of the brain due to heterogeneous complications that continue after the initial trauma. As a result, stem cell therapy is viewed as a potential treatment approach that can be instituted during the chronic phase of TBI. This study employs Diffusion Tensor Imaging (DTI) to non-destructively probe the pathological impacts of endogenous Neural Progenitor Cells (NPC) and exogenous Mesenchymal Stem Cells (MSC) in a rodent model of TBI. This study represents the first investigation of the efficacy of MSC treatment in TBI and the potential synergistic effect of MSC and NPC. |
| 3365 | Computer #58 |
Tract-based longitudinal analysis of microstructural diffusion changes of mild traumatic brain injury in sports |
1Department of Radiology, Stanford University, Stanford, CA, United States, 2Sports Medicine, Stanford University, Stanford, CA, United States, 3Department of Neurosurgery, Stanford University, Stanford, CA, United States |
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While many cross sectional DTI studies have been performed for mild TBI in sports, very few longitudinal investigations have been performed. We present here a large longitudinal study assessing white matter integrity in high vs. low contact sports employing whole brain automated tractography and NODDI. We performed a tract-based analysis at baseline and longitudinally over 3 years, with both experiments localizing diffusion changes along the callosum forceps minor, left thalamic radiation and the superior longitudinal fasciculus. We have also shown that diffusion metrics correlate with cognition as assessed by the SCAT scores. |
| 3366 | Computer #59 |
Decrease in myelin water fraction of global white matter and white matter tracts in traumatic brain injury (TBI). |
1UBC MRI Research Centre, Radiology, University of British Columbia, Vancouver, BC, Canada, 2Radiology, University of British Columbia, Vancouver, BC, Canada, 3Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada, 4Physical Therapy, University of British Columbia, Vancouver, Canada, 5Psychiatry, University of British Columbia, Vancouver, Canada, 6Physical Therapy, University of British Columbia, Vancouver, BC, Canada |
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Chronic traumatic brain injury (TBI) was examined using myelin water fraction (MWF) in global white matter and tracts for subjects undergoing intensive cognitive training (Arrowsmith Program) compared to age and gender matched controls. MWF was significantly lower in TBI subjects and correlations were found between MWF and cognitive scores of fluid and crystallized ability. However, after 3 months of cognitive training no significant differences were found in MWF in TBI subjects. |
| 3367 | Computer #60 |
Cerebellar surface mapping using T1 and T2* relaxometry at ultrahigh-field MRI: from macroscale to microscale? |
1Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 3Siemens Healthcare Pty Ltd., Brisbane, Australia, 4University of Queensland, St-Lucia, Australia, 5University of Lausanne, Lausanne, Switzerland, 6Advanced Clinical Imaging Technology Group, Siemens, Lausanne, Switzerland, 7Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland, 8Healthcare Sector IM&WS S, Siemens Schweiz AG, Lausanne, Switzerland, 9Spinoza Centre for Neuroimaging, Amsterdam, Switzerland, 10Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States |
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The quantitative properties of the cerebellum were assessed by acquiring T1 and T2*contrasts at 7T and mapping these onto the cerebellar cortex. T1 maps showed medial-lateral alternating stripes of different intensities while T2* values were homogeneously distributed across the lobes. This study showed the heterogeneity of the cerebellar cortex in terms of tissue content, which in part parallels a well-established gene expression pattern. |
| 3368 | Computer #61 |
Characterizing the cortical terminations of the arcuate fasciculus with diffusion microstructure |
1USC Mark and Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, United States |
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The arcuate fasciculus (AF) is a group of association fibers consisting of 3 subcomponents that link perisylvian language centers in the frontal, temporal, and parietal lobes. The purpose of this study is to characterize the diffusion microstructural properties and functional outcomes of the cortical AF terminations in the right and left hemispheres. Multi-shell diffusion models were used to extract relative compartment densities, which were compared in cortical regions where AF fibers terminated. The results of this study show that perisylvian language centers exhibit differential cytoarchitecture that can be measured with in vivo MRI measures. |
| 3369 | Computer #62 |
A simple method to scale the macromolecular pool size ratio for computing the g-ratio in vivo |
1Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton, United Kingdom, 2Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy |
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previous work suggested that the myelin volume fraction (MVF) is proportional to the macromolecular pool size ratio, F, derived from Magnetization Transfer (MT). However the proportionality constant seems to be dependent on the specific MT model, and requires histological validation. Here we propose a simple method based to derive such a constant. |
| 3370 | Computer #63 |
Axon Loss Detected by Diffusion Basis Spectrum Imaging (DBSI) in the Absence of Atrophy |
1Radiology, Washington University School of Medicine, St. Louis, MO, United States, 2Obstertic and Gynecology, Washington University School of Medicine, St. Louis, MO, United States, 3The Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States, 4Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States |
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The extent of axonal loss plays a significant role in irreversible neurological impairment in optic nerve crush (ONC). We detected significant 15% axonal loss in the absence of statistically significant atrophy using diffusion basis spectrum imaging (DBSI) 7 days after ONC in mice. |
| 3371
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Computer #64 |
Oral citicoline treatment improves visuomotor response and white matter integrity in the visual pathway after chronic intraocular pressure elevation |
1Neuroimaging Laboratory, University of Pittsburgh, Pittsburgh, PA, United States, 2Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States, 3Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States, 4Department of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong, China, People's Republic of, 5Division of Biomedical Engineering, Hong Kong University of Science and Technology, Hong Kong, China, People's Republic of, 6University Eye Center, Hong Kong Eye Hospital, Hong Kong, China, People's Republic of, 7Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, China, People's Republic of, 8Center for Neuroscience Imaging Research, Institute for Basic Science, Sungkyunkwan University, Kuwon, Korea, Democratic People's Republic of |
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Glaucoma is a neurodegenerative disease that can cause irreversible blindness. Lowering intraocular pressure (IOP) is currently the only clinically approved treatment method for glaucoma, however the disease may still progress in some patients after lowering IOP. Citicoline has been suggested as a potential therapeutic for neurodegenerative diseases including glaucoma, but its neuroprotective effect remains incompletely understood. In this study, we determined the effects of oral citicoline treatment on visual function and white matter preservation in an experimental glaucoma model. The results show that citicoline treatment slowed the worsening of visual acuity and preserved white matter integrity along the visual pathway |
| 3372 | Computer #65 |
G-ratio distribution within the healthy population: the effect of age and gender |
1Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton, United Kingdom, 2Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy, 3Santa Lucia Foundation, Rome, Italy, 4Brighton and Sussex Medical School, Brighton, United Kingdom |
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This paper investigates the variability of the g-ratio (the ratio of the inner to the outer diameter of a myelinated axon) as a function of age and gender in the healthy population. By combining magnetization transfer and diffusion MRI, the mean g-ratio of 20 white matter tracts was estimated, revealing no gender differences, and a systematic increase with age. Righ vs left hemisphere differences were also detected. |
| 3373 | Computer #66 |
Transient Changes in White Matter Microstructure during Anesthesia |
1Radiology & Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 3Anesthesiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 4Icahn School of Medicine at Mount Sinai, New York, NY, United States, 5Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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The effect of general anesthesia was studied in brain white matter of healthy control elderly subjects. DTI measures were compared between awake and general anesthesia conditions. We found significant transient decreases in Fractional Anisotropy and increases in Mean Diffusivities throughout the brain. |
| 3374 | Computer #67 |
Mouse Brain Microscopy with Loop Gap Resonator at 15T |
1Athinoula A. Martinos Center, Charlestown, MA, United States, 2Radiology, Massachusetts General Hospital, Boston, MA, United States |
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Construction of a loop-gap-resonator RF coil for MR microscopy of ex vivo mouse brains at 15T is described. The large signal obtained allowed acquisition of 20μm3 isotropic voxels, the highest resolution yet achieved in MR mouse brain imaging. Importantly, the high resolution allowed clear identification of multiple brain structures and will be of interest to researchers working with various mouse models. |
| 3375 | Computer #68 |
Super-Resolution MR imaging of ex-vivo eye-globe structures at 7T |
1Imaging Institute, Cleveland Clinic Foundation, Cleveland, OH, United States, 2Department of Ophthalmic Oncology, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, United States |
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We demonstrate a high-resolution ex-vivo globe image using 7T. With voxel size of 250μm isotropic resolution, detailed structures of the globe were clearly identified. Our results show that the high-resolution MR imaging is particularly useful in helping to visualize inner structure of eye-globe. Moreover, it is successfully demonstrated the sensitivity to choroidal melanoma. In addition, we have performed MRI scans using human globe specimens to investigate the contribution of fixation to the evolution of T2 over time and measured SNR changes as function of the number of excitations to gain some insight into the optimal average number. |
| 3376
|
Computer #69 |
An automated pipeline for mouse brain morphometric MRI |
1Istituto Italiano di Tecnologia, Rovereto, Italy, 2Center for Mind and Brain Sciences, Rovereto, Italy, 3IMT - Institute for Advanced Studies, Lucca, Italy, 4Institute of Digital Communications, School of Engineering, The University of Edinburgh, Edinburgh, United Kingdom |
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We provide a detailed description of registration-based procedures for voxel based morphometry, cortical thickness estimation and automated anatomical labelling of the mouse brain. To illustrate our procedures, we described their application to quantify morphological differences in two inbred mouse strains characterised by different social behaviour. We show that our approach can reliably detect both focal and large scale gray matter alterations using complementary readouts. The operational workflows described here are expected to help the implementation of rodent morphoanatomical methods by non-expert users, and promote the use of these tools across the preclinical neuroimaging community. |
| 3377 | Computer #70 |
Magnetic Resonance Myelin G-ratio mapping for the Brain and Cervical Spinal Cord: 10 Minutes Protocol for Clinical Application |
1Radiology, Juntendo University School of Medicine, Tokyo, Japan, 2Tokyo Medical Clinic, Tokyo, Japan, 3Ecole Polytechnique, University of Montreal, Montreal, QC, Canada, 4Siemens Japan, Tokyo, Japan, 5Radiology, The University of Tokyo, Tokyo, Japan |
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The purpose of this exhibit is to present the feasibility of MR g-ratio mapping for whole brain and cervical spinal cord using a 10 minute protocol. This protocol is appropriate for clinical use and provides reasonable image quality for clinical diagnosis. In vivo MR g-ratio mapping warrants daily clinical use as it has potential to provide additional information about WM microstructure and its changes in pathology. |
| 3378 | Computer #71 |
Macromolecular proton fraction as an ultimate source of brain tissue contrast in ultra-high magnetic fields |
1Radiology, University of Washington, Seattle, WA, United States, 2National Research Tomsk State University, Tomsk, Russian Federation, 3Institute of Cytology and Genetics, Novosibirsk, Russian Federation |
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This study provides methodological background for neuroimaging applications of fast 3D MPF mapping in ultra-high magnetic fields and demonstrates that MPF presents the most effective source of high-field brain tissue contrast. Unique contrast features, high spatial resolution, and the capability to provide quantitative information about myelination make MPF mapping an ultimate tool for small animal neuroimaging in high magnetic fields. |
| 3379 | Computer #72 |
Whole human brain diffusion MRI at 450µm post mortem with dwSSFP and a specialized 9.4T RF-coil |
1Dept. of Cognitive Neuroscience, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht, Netherlands, 2FMRIB Centre, University of Oxford, Oxford, United Kingdom, 3Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany |
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The investigation of whole human brains post mortem with large bore systems can achieve a resolution considerably superior to that achievable in-vivo. However, the achievable resolutions and contrast are limited, especially for diffusion MRI (dMRI), by gradient performance, non-optimized RF-coils, and RF-field inhomogeneity and decreasing T2 with increasing B0. Here we report on ultrahigh resolution (450µm) diffusion imaging of the whole human brain showing exquisite spatial definition. This is achieved using a specialized 9.4T 8Ch parallel transmit (pTx), 24Ch receive RF-coil and a diffusion weighted steady state free precession (dwSSFP) sequence extended with a kt-points excitation pulse for B1+ homogenization |
| Exhibition Hall | Tuesday, May 10, 2016: 13:30 - 14:30 |
| 3380 | Computer #73 |
Does tau pathology play a role in abnormal iron deposition in Alzheimer’s Disease? A quantitative susceptibility mapping study in the rTg4510 mouse model of Tauopathy |
1Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom, 2Eli Lilly & Co. Ltd, Surrey, United Kingdom, 3Eli Lilly and Company, Indianapolis, IN, United States, 4Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom |
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In this work, quantitative susceptibility mapping (QSM) and T2* mapping were used to investigate iron accumulation both in-vivo and ex-vivo in a mouse model of Alzheimer's Disease exhibiting tau pathology for the first time. Magnetic susceptibility increases relative to controls were identified in grey matter and white matter brain regions and may indicate sensitivity to tissue iron content. QSM in this mouse model may therefore provide a non invasive method by which to dissect the relationship between iron and tau pathology in Alzheimer's Disease. |
| 3381 | Computer #74 |
T2-weighted imaging of substantia nigra pars compacta shows increased iron deposition in ventral lateral tier |
1Department of Biomedical Engineering, Emory University & Georgia Tech, Atlanta, GA, United States, 2Department of Neuroradiology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany, 3Department of Neurology, Emory University, Atlanta, GA, United States, 4Department of Neurology, University Medical Center Würzburg, Würzburg, Germany |
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Recent results found that the SN seen in neuromenalnin sensitive MRI and iron sensitive T2-weighted contrasts is located in disparate spatial positions in controls. Since iron is known to be deposited in the SN after onset of Parkinson's disease(PD), we re-examine iron sensitive measurements with respect to these new findings in this abstract. Specifically, we find that the SN seen in T2-weighted contrasts is enlarged in inferiorly and medially when compared to controls. Most of this discrepancy happens in the NM SN and we found the overlap to be an incredibly sensitive marker for PD (p<10-15). |
| 3382 | Computer #75 |
Association of Brain Iron Deposition in Parkinson’s Disease with Comorbidities of Visual Hallucinations: An ROI-based Quantitative Susceptibility Mapping Study |
1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong, 2Philips Healthcare, Hong Kong, Hong Kong, 3Department of Psychiatry, Yale University, New Haven, CT, United States, 4Department of Psychiatry, The University of Hong Kong, Hong Kong, Hong Kong, 5Department of Forensic and Neurodevelopmental Science, King’s College London, London, United Kingdom, 6Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong |
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Abnormal iron accumulation in the brain may cause oxidative-stress-induced neurodegeneration, which is one of the hypothesis of nigral cell death in PD. It was also believed that non-motor symptoms of PD patients are associated with the increased of brain iron content. This study examined the iron concentration in several subcortical structures of PD patients with visual hallucinations by using the QSM technique. Higher magnetic susceptibility was observed in the hippocampus of this patient group. The result supported the hypothesis that hippocampal abnormality could induce visuospatial memory impairment which may be the cause of visual hallucination in PD patients. |
| 3383 | Computer #76 |
Evaluation of gray matter degeneration in Parkinson’s disease by using neurite-orientation dispersion and density imaging: Analysis by gray matter-based spatial statistics |
1Department of Radiology, Juntendo University, Tokyo, Japan, 2Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan, 3Department of Neurology, Juntendo University, Tokyo, Japan, 4Department of Diagnostic Radiology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan |
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In this study, neurite-orientation dispersion and density imaging were used to estimate structural changes of neurites in the gray matter of the brain, which is the earliest pathological change in patients with PD. The results showed a significant decrease in the intracellular volume fraction in the right amygdala and right putamen in PD, suggesting a decrease in neurite density that may reflect actual pathological change. Given that NODDI could detect pathological changes at the earliest stages in PD, it may be useful for early diagnosis. |
| 3384 | Computer #77 |
Evaluation of different high-pass filter on the susceptibility in patients Parkinson’s disease and controls |
1Medical Imaging, The Ottawa Hospital, Ottawa, ON, Canada, 2Radiology, University of Ottawa, Ottawa, ON, Canada, 3King Saud University, Riyadh, Saudi Arabia |
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Quantitative susceptibility mapping (QSM) was found as a useful method to evaluate neurodegenerative diseases such as Parkinson’s disease. For QSM reconstruction background field removed phase data is needed, but for retrospective studies only high-pass filtered data might be available. In this study we analyzed the influence of different high-pass filtered phase images on the susceptibility assessment for volunteers and Parkinson’s disease patients and compared the results to QSM estimation using background field removed phase data. With increasing high-pass filter strength consistently lower susceptibility results, but up to a certain filter strength differences in susceptibility can still be distinguished. |
| 3385 | Computer #78 |
Imaging effects of memantine treatment in a mouse model of Huntington disease using evoked and resting-state fMRI |
1SBIC, A*STAR, Singapore, Singapore, 2TLGM, A*STAR, Singapore, Singapore, 3Department of Medicine, National University of Singapore, Singapore, Singapore |
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Huntington disease (HD) is an incurable neurodegenerative disease. Recently, memantine (MMT) was found to be effective delaying the progression of disease phenotypes in a mouse model of HD. Here we applied resting-state fMRI to evaluate functional connectivity in HD and the MMT treatment effect and its behavioral correlates. The results of forepaw stimulation reduced evoked responses though significance was hampered by large individual variation. Interestingly, functional connectivity outside of DMN, but not within DMN, was decreased by HD. With MMT treatment, the connectivity increased in general. The FC relevant to the behavioral test also showed behavioral correlates. |
| 3386 | Computer #79 |
Developmental White Matter Alterations in Monkey Brains with Huntington’s Disease |
1Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States, 2Department of Human Genetics, School of Medicine, Emory University, Atlanta, GA, United States, 3Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States |
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This study examined the developmental changes of white matter integrity in rhesus monkey brains with the HD gene mutation using diffusion tensor imaging (DTI). Widespread developmental alterations are seen in striatum, and the frontal, motor, sensory and visual brain areas. The findings reveal the temporal-spatial evolution of abnormal white matter maturation during the development of the brain with the Huntington’s Disease, and suggest altered neural substrates associated with motor and cognitive dysfunctions in HD patients. |
| 3387 | Computer #80 |
Diffusion tensor imaging of the substantia nigra in Parkinson’s disease revisited |
1Department of Biomedical Engineering, Emory University & Georgia Tech, Atlanta, GA, United States, 2Department of Neurology, Emory University, Atlanta, GA, United States |
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Inconclusive results from prior diffusion tensor imaging-based studies can be attributed to variability in location of regions of interest used to define the substantia nigra and its subcomponents. We apply recent findings from neuromelanin sensitive MRI to standardize regions of interest for the substantia nigra. Differences in fractional anisotropy and mean diffusivity were found in the neuromelanin sensitive substantia nigra but not in the substantia nigra defined in the b0 image. |
| 3388 | Computer #81 |
Diagnosis of Parkinsonism Using Nigrosome 1 Imaging at 3T: Comparison of Interobserver Agreement between GRE Magnitude Images (MEDIC) and Susceptibility Map-weighted Images (SMWI) |
1Radiology, Gachon University Gil Medical Center, Incheon, Korea, Republic of, 2Radiology, Seoul St. Mary Hospital, Seoul, Korea, Republic of, 3Neurology, Gachon University Gil Medical Center, Incheon, Korea, Republic of, 4Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of |
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Susceptibility map-weighted imaging (SMWI) improves both CNR and SNR in comparison with conventional SWI. In this work, we compared SMWI with MEDIC (a multi-echo GRE imaging that combines magnitude images via sum of squares) for nigrosome 1 imaging at 3T in terms of interobserver agreement and diagnostic performance in 74 subjects (44 with Parkinson’s disease). Two experienced and two less-experienced reviewers visually assessed both imaging sets separately. Compared with MEDIC, SMWI showed higher kappa values and larger AUCs, regardless of level of experience. As a result, nigrosome 1 imaging using SMWI significantly improved diagnostic performance as well as interobserver agreement. |
| 3389 | Computer #82 |
Sensitivity of volumetric MRI and MRS to onset and progression of neurodegeneration |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, United States, 3Division of Biostatistics, University of Minnesota, Minneapolis, MN, United States, 4University of Oxford, Oxford, United Kingdom, 5Department of Neurology, University of Chicago, Chicago, IL, United States, 6Department of Neurology, University of Minnesota, Minneapolis, MN, United States |
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The goal of this study was to combine MRS with volumetric MRI to determine the sensitivity of these two techniques to onset and progression of neurodegeneration in patients with early-moderate spinocerebellar ataxia type 1. Subjects were scanned at baseline and followed up at ~18 and ~36 months at 3T. Both MRI and MRS measures were found to be more sensitive to disease progression than standardized clinical scores. This study shows that volumetric MRI was most sensitive to disease progression while MRS might be more sensitive to detect the disease’s early stage. |
| 3390 | Computer #83 |
QSM and T2* Mapping in a Six Month Placebo-Controlled Clinical Trial of the Iron Chelator Deferiprone in Parkinson’s Disease |
1Imanova Centre for Imaging Sciences, London, United Kingdom, 2Imperial College London, London, United Kingdom |
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A double-blind placebo-controlled clinical trial of an iron chelation therapy was performed in 25 subjects with Parkinson’s disease (PD) and 12 healthy matched controls. Two MRI measures of brain iron at each of three visits at baseline, 3 months, and 6 months were derived from a high resolution 3D multiecho volume: T2* and QSM maps. T2* values significantly lengthened in six of nine pre-defined ROIs by the final visit in the highest dose group. QSM values , however, did not change with treatment. This differential trajectory between relaxation and susceptibility may result from ferritin’s complex relaxation behavior. |
| 3391 | Computer #84 |
Characterizing neurodegeneration in progressive supranuclear palsy using VBM and SVM classification |
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Department of Neurology and Center of Clinical Neuroscience, Charles University in Prague, Prague, Czech Republic, 31st Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic, 4Institute for Clinical and Experimental Medicine, Prague, Czech Republic, 5Clinic and Polyclinic for Neurology, Saarland University Homburg, Homburg, Germany, 6Clinic and Polyclinic for Neurology, University of Ulm, Ulm, Germany, 7Clinic for Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany |
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Structural brain differences were investigated between patients with progressive supranuclear palsy (PSP) and healthy controls with T1-weighted images (MP-RAGE) acquired at four centers with different 3T scanners (Siemens). Using voxel-based morphometry, we found a major decline in gray matter density in brainstem, insula, striatum, and frontomedian regions that is in line with the current literature. Support-vector-machine classification provided a high sensitivity of disease detection when using relevant brain regions in feature selection. |
| 3392 | Computer #85 |
Robust global and widespread local white matter abnormalities in a longitudinal study of juvenile neuronal ceroid lipofuscinosis (CLN3) |
1Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland, 2iMinds-Vision Lab, Department of Physics, University of Antwerp, Wilrijk (Antwerp), Belgium, 3HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland, 4Child Psychiatry, University of Helsinki and Helsinki University Hospital, Helsinki, Finland, 5Department of Child Neurology, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland |
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Juvenile neuronal ceroid lipofuscinosis (CLN3), is a progressive neurodegenerative lysosomal storage disease of the childhood, which manifests with loss of vision, seizures and loss of cognitive and motor functions, and leads to premature death. We investigated global and local white matter microstructure with diffusion MRI in 14 children with CLN3 imaged at two time points. Robust global analysis was performed using whole-brain tractography and white matter tract skeleton. Local microstructural abnormalities were investigated using tract-based spatial statistics. Significantly decreased fractional anisotropy and increased diffusivity values were found in subjects with CLN3 both at the global and local scale. |
| 3393 | Computer #86 |
Structural brain connectome and cognitive impairment in Parkinson’s disease |
1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Clinic of Neurology, Faculty of Medicine, University of Belgrade, Belgrade, Yugoslavia, 3Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, Netherlands, 4Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy |
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To date, MRI biomarkers have been demonstrated extremely useful for detecting and monitoring the neurodegenerative processes. However, brain network analysis seems the most powerful approach to quantitatively describe the topological organization of the brain connectome even at early stages of neurodegenerative diseases. This study provided promising biomarkers to detect features of neurodegeneration in PD-MCI, being able to distinguish it from PD without MCI. This study shows that the presence of subtle cognitive deficits not causing a dementia, produces a huge alteration of brain networks suggesting the importance of the study of connectomics in the investigation of neurodegenerative diseases. |
| 3394 | Computer #87 |
fMRI reveals plasticity compensating for early dopaminergic loss at corticostriatal synapse |
1Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan |
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The dopaminergic system possesses striking plasticity compensating for motor aberrations from neuronal loss. Little is known regarding the compensation mechanism during dopaminergic loss, preventing the aberration from being arrested and treated early. Here we present in vivo imaging evidence from functional magnetic resonance imaging showing that, after dopaminergic depletion, the dorsolateral striatum (DOLS) exhibited an early and transient vasodilation cluster in response to specific forepaw stimulation. Activation of DOLS NMDA receptors causes this vasodilation, protects dopaminergic fibers from denervation, and counteracts motor deficits. The findings have clinical implications for early detection and intervention in brain disorders such as Parkinson’s disease. |
| 3395 | Computer #88 |
Dopaminergic therapy modulates cortical perfusion in Parkinson’s disease with and without dementia according to ASL perfusion MRI |
1GE Healthcare, Taipei, Taiwan, 2Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, 3Department of Nuclear Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, 4Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, 5Department of Nuerosurgery, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan, 6Brain Research Center, National Yang-Ming University, Taipei, Taiwan |
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We examined the cerebral perfusion differences among 17 Parkinson’s disease (PD) patients, 17 PD with dementia (PDD) patients, and 17 healthy controls and used noncontrast arterial spin labelling MRI to assess the effects of dopaminergic therapies on perfusion in the patients. We demonstrated progressive widespread cortical hypoperfusion in PD and PDD and robust effects for the dopaminergic therapies. These patterns of hypoperfusion could be related to cognitive dysfunctions and disease severity. Furthermore, desensitization to dopaminergic therapies in terms of cortical perfusion was found as the disease progressed, supporting the concept that long-term therapies are associated with the therapeutic window narrowing. |
| 3396 | Computer #89 |
Aberrant interhemispheric structural and functional connectivity in amyotrophic lateral sclerosis: converging evidences from DTI and resting-state fMRI |
1Department of Radiology, Southwest Hospital, Chongqing, China, People's Republic of, 2Department of Biomedical Engineering, Emory University & Georgia Institute of Technology, Atlanta, GA, United States, 3University of Shanghai for Science & Technology, Shanghai, China, People's Republic of, 4Department of Neurology, Southwest Hospital, Chongqing, China, People's Republic of, 5Department of Biomedical Engineering, Perking University, Beijing, China, People's Republic of |
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The corpus callosum (CC) involvement is a consistent feature of Amyotrophic lateral sclerosis (ALS), thus suggesting a pathopysiology of reduced interhemispheric neural connectivity. In the current study, we directly examined the interhemispheric functional and structural connectivities in ALS. In terms of functional connectivity, extensive alterations in voxel mirrored homotopic connectivity were found in ALS. With structural connectivity, while there were widespread reductions in DTI metrics, only the fiber probability index through CC subregion III in the ALS patients was significantly decreased compared with the controls. These findings provide further evidence for structural and functional interhemispheric connectivity impairment in ALS. |
| 3397 | Computer #90 |
Investigation of inter-hemispheric functional connectivity in Parkinson's disease with asymmetric onset using Voxel-Mirrored Homotopic Connectivity |
1MR Research China, GE Healthcare, Beijing, China, People's Republic of, 2Radiology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China, People's Republic of, 3GE Healthcare, Menlo Park, CA, United States |
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This preliminary study used voxel-mirrored homotopic connectivity (VMHC), a novel resting-state fMRI parameter to investigate inter-hemispheric functional connectivity in Parkinson’s Disease (PD) with asymmetric onset. Fifteen left side onset (LPD) patients, sixteen right side onset (RPD) patients and nineteen healthy controls were recruited for comparison. Both of LPD and RPD patients showed decreased VMHC in post-central gyrus responsible for motor functions. The decreased VMHC in the cuneus and middle occipital gyrus in LPD patients might affect visual processing function. For RPD patients, VMHC changes in the middle and superior frontal gyrus could be relevant to advanced cognitive impairment. |
| 3398 | Computer #91 |
Can longitudinal diffusion-weighted imaging of the basal ganglia be used as a surrogate marker in preclinical Huntington’s disease? |
1FMRIB Centre, University of Oxford, Oxford, United Kingdom, 2Oxford, United Kingdom, 3San Diego, CA, United States |
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Huntington’s disease is a monogenetic, neurodegenerative movement disorder that is amenable to predictive genetic testing. Here, we investigated whether longitudinal diffusion-weighted imaging of the basal ganglia could be used to detect early microstructural changes in participants with presymptomatic Huntington’s disease (preHD). We found the first results showing significant longitudinal changes in the microstructure of the basal ganglia within a preclinical HD population. We further showed that, while FA and MD might be less sensitive to longitudinal changes than volumetric measures, they provide mechanistic insights into the underlying physiopathological process that are complementary to the monotonic, non-specific changes in the volume of the basal ganglia. |
| 3399 | Computer #92 |
Brain Iron Deficiency in Restless Legs Syndrome Measured by Quantitative Susceptibility and its Relation to Clinical Features |
1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 2Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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Possible brain iron deficiency was assessed using quantitative susceptibility mapping at 7T in restless legs syndrome (RLS) and analyzed with clinical measurements including IRLS severity score, serum iron, serum ferritin and periodic limb movement during sleep (PLMS). Using magnetic susceptibility as a brain iron index and compared to control group, significantly decreased iron was found in RLS patients in dentate nuclei and thalamus, and in substantia nigra in a subset of RLS patients with severe clinical symptoms with PLMS larger than 100 times per hour. Significant correlation between PLMS and brain iron was only found in substantia nigra in RLS. |
| 3400 | Computer #93 |
Quantitative Susceptibility Mapping of the “Swallow tail” in Parkinson disease |
1Medical Imaging, The Ottawa Hospital, Ottawa, ON, Canada, 2Radiology, University of Ottawa, Ottawa, ON, Canada, 3King Saud University, Riyadh, Saudi Arabia, 4Neurology, The Ottawa Hospital, Ottawa, ON, Canada |
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Parkinson disease (PD) continues to be diagnosed based on clinical findings. Recently, in SWI images, the loss of ‘swallow tail’ appearance in dorsolateral substantia nigra in PD patients yielded high diagnostic accuracy. In our study we measured susceptibility values using QSM in the ‘swallow tail’ area in seven Parkinson’s disease patients and compared to five control subjects. The susceptibility in the swallow tail area was higher in the PD group (0.072 vs. 0.058). This likely suggests increased iron deposition causing a masking effect that contributes along with dopaminergic neurons loss to the disappearance of the ‘swallow tail’ in PD patients. |
| 3401 | Computer #94 |
MRI signatures in the brain of patients with PD and iRBD |
1CMRR, Department of Radiology, University of Minnesota, Minneapolis, MN, United States, 2Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States, 3Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic, 4Department of Neurology, University of Minnesota, Minneapolis, MN, United States, 5A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland, 6Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 7Division of Biostatistics, University of Minnesota, Minneapolis, MN, United States |
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The idiopathic rapid eye movement sleep behavior disorder (iRBD) is a condition that often evolves into Parkinson’s disease (PD), therefore by monitoring iRBD one can track the neurodegeneration of individuals that may progress to PD. Here we used a battery of MRI contrasts to characterize brain tissue properties such as microstructural integrity, iron loads, and functional connectivity in 10 iRBD, 10 PD and 10 age-matched healthy subjects. Rotating frame relaxation methods adiabatic T1,2ρ and RAFFn, along with DTI and rsfMRI detected heterogeneous abnormalities in several subcortical structures of PD and iRBD subjects. |
| 3402 | Computer #95 |
A High b-Value Diffusion Study of Brainstem Abnormality in Patients with Parkinson's Disease Using a CTRW Model |
1Center for MR Research, Chicago, IL, United States, 2Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 3Neurological Sciences, Rush University Medical Center, Chicago, IL, United States, 4Radiology, Neurosurgery and Bioengineering, University of Illinois Hospital & Health Sciences system, Chicago, IL, United States |
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It has been known that the substantia nigra of brain stem shows structural abnormalities with the progression of Parkinson’s disease. While high b-value diffusion imaging has the potential to reveal such structural changes, single-shot EPI suffers from unwanted geometric distortion which may result in poor analysis of the diffusion data. In this study, we use a recently developed reduced field of view imaging technique and analyze the abnormalities occurring in the substantia nigra of the Parkinson’s disease patients by using the continuous-time random-walk (CTRW) model. |
| 3403 | Computer #96 |
The Effect of Primidone on Gamma-Aminobutyric Acid Concentration in the Dentate Nucleus in Patients with Essential Tremor |
1School of Health Sciences, Purdue University, West Lafayette, IN, United States, 2Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States, 3Department of Neurology, Yale School of Medicine, New Heaven, CT, United States, 4Department of Radiology, Weill Cornell Medical College, New York, NY, United States, 5Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, New Heaven, CT, United States, 6Department of Chronic Disease Epidemiology, Yale School of Public Health, New Heaven, CT, United States |
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Whether current use of the medication primidone affects dentate γ-aminobutyric acid (GABA) concentrations is unknown. Yet, this may be an important confounder in studies of the pathophysiology of essential tremor (ET). Using the MEGA-PRESS J-editing sequence, we found no difference in dentate GABA levels between patients taking primidone and patients not taking primidone. Furthermore, there was no association between daily primidone dose and dentate GABA concentration. These data suggest that it is not necessary to exclude ET patients on primidone from MRS studies of dentate GABA concentration. |
| Exhibition Hall | Tuesday, May 10, 2016: 14:30 - 15:30 |
| 3404 | Computer #1 |
Ex-Vivo Diffusion Anisotropy of Human Brain Hemispheres |
1Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States, 2Department of Biomedical Engineering, Illinois Institute of Technology, chicago, IL, United States, 3Rush Alzheimer's Disease Center, Rush University Medical Center, chicago, IL, United States |
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The aims of this work were to: 1) longitudinally assess the diffusion anisotropy of various white matter regions measured with ex-vivo MRI, and 2) investigate the relationship between FA values measured in-vivo and ex-vivo on the same subjects. This work demonstrated that brain white matter diffusion anisotropy measured ex-vivo decreases with time postmortem, and that diffusion anisotropy measured ex-vivo is linearly related to the diffusion anisotropy measured in-vivo on the same subjects. Combination of ex-vivo MR diffusion anisotropy and histopathology may become an effective tool for the assessment of the neuropathologic correlates of structural brain abnormalities observed in-vivo. |
| 3405 | Computer #2 |
Faster brain atrophy is associated with accelerated cognitive decline in healthy older adults: the Singapore Longitudinal Ageing Brain Study |
1Center for Cognitive Neuroscience, Duke-NUS Graduate Medical School, Singapore, Singapore |
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Although East Asia harbors the largest number of aging adults in the world, there is limited data on longitudinal changes in brain structure and its relationship with domain-specific cognition. We tracked changes in brain volume and 5 cognitive functions over 8 years among healthy older adults in the Singapore-Longitudinal Aging Brain Study. After adjusting for intracranial volume, demographic factors, and blood pressure, total cerebral atrophy was associated with faster decline in verbal memory. Hippocampal atrophy and ventricular expansion were associated with greater decline in verbal memory and executive functions. These findings clarify the relationships between age-trends in neurobiology and cognition. |
| 3406 | Computer #3 |
Age-related alterations in glutamatergic neurotransmission in the anterior and posterior cingulate cortices |
1Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong, 2Philips Healthcare, Hong Kong, Hong Kong, Hong Kong, 3Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia, 4School of Biomedical Sciences, The University of Hong Kong, Hong Kong, Hong Kong, 5Neuropsychology and Applied Cognitive Neuroscience Laboratory, Chinese Academy of Sciences, Beijing, China, People's Republic of, 6Medicine, Queen Mary Hospital, Hong Kong, Hong Kong |
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Glutamatergic neurotransmission has an interesting role in aging. The anterior cingulate cortex(ACC) and posterior cingulate cortex(PCC) are focuses for aging research due to their implicated role in cognition. In this study, proton magnetic resonance spectroscopy was used to investigate the changes in glutamatergic neurotransmission during aging by measuring absolute Glx concentration([Glx]abs) in ACC and PCC in a local Chinese cohort at 3.0T. Significant age-related increases of [Glx]abs in ACC and PCC might indicate age-related alterations in glutamatergic neurotransmission. Significantly higher overall [Glx]abs was found in ACC compared with PCC might be attributed to the abundant glutamatergic neurons in the forebrain. |
| 3407 | Computer #4 |
Cumulative Mid-Life Framingham Stroke Risk Profile Predicts Reduced Structural Brain Integrity in Old Age |
1Psychiatry, University of Oxford, Oxford, United Kingdom, 2Epidemiology and Public Health, University College London, London, United Kingdom |
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Research presented discusses the cumulative effects of Framingham Stroke Risk profile in mid-life on structural brain integrity reduction in older life. |
| 3408 | Computer #5 |
Early aging effect on the function of human central olfactory system |
1Penn State College of Medicine, Hershey, PA, United States |
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We report an olfactory fMRI study of the aging effect on the functions of central olfactory system during normal adulthood and early aging. The smell identification function declined with age. Accordingly, the BOLD signal responding to odor stimulations was significantly decreased with age in bilateral DLPFC, left orbitofrontal cortex, and left insula. However, there was no significant age correlation was detected with the BOLD signal in the primary olfactory cortex. These results suggest that age-related olfactory functional decline in human brain is more prominent in the secondary and higher order central olfactory structures than the POC in early aging process. |
| 3409 | Computer #6 |
Distribution of principal diffusion direction orientations: a novel method to characterize age-related changes in the brain. |
1Institute of Bioimaging and Molecular Physiology (IBFM), National Research Council, Catanzaro, Italy, 2Institute of Neurology, University Magna Graecia, Catanzaro, Italy |
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Diffusion-weighted MRI of the brain allows the assessment of tissue integrity at the microscale. The most commonly used technique to analyze diffusion-weighted data is diffusion tensor imaging (DTI), which relies on the reconstruction of the diffusion tensor at each MRI voxel by calculating its eigenvalues and eigenvectors. These quantities allow the estimation of scalar DTI maps measuring mean diffusivity (MD) and fractional anisotropy (FA), which are considered markers of structural tissue integrity. To date, DTI has been extensively used in the field of neuroimaging to study brain microstructural integrity in healthy subjects and patients with several different neurological conditions. However, despite the three-dimensional nature of the tensor, existing studies have focused on changes in DTI-derived scalar indexes, such as MD and FA, not considering the orientation of the principal eigenvector of the tensor, which could provide invaluable insight on the nature of tissue changes, but is still only used for color-coding FA maps for qualitative, visual purposes. |
| 3410 | Computer #7 |
Intra Voxel Incoherent Motion (IVIM) in Brain Regions: a Repeatability and Aging Study |
1Biosciences, SRI International, Menlo Park, CA, United States, 2Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States |
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This work investigates the inter- and intra-session repeatability and the effects of age on intra voxel incoherent motion (IVIM) parameters. Atlas registration allowed for parcellation-based region specific brain analysis. A new and robust fitting approach reliably identified the perfusion fraction, diffusion, and pseudo-perfusion parameters from 15 healthy normal volunteers. The results show that IVIM is repeatable and that the perfusion fraction, diffusion, and pseudo-perfusion parameters are significantly higher in older than younger adults in several brain regions, most likely from perivascular CSF infiltration. This work serves to highlight how age is an important factor to consider when using IVIM. |
| 3411 | Computer #8 |
Altered neurochemical profile in the healthy elderly measured via 7 T 1H MRS |
1University of Minnesota, Minneapolis, MN, United States, 2Minneapolis VA Medical Center, Minneapolis, MN, United States |
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The goal of this work was to characterize differences in the concentrations of neurochemicals beyond tNAA, tCr, and tCho in the OCC and PCC regions of healthy young and elderly subjects. The key innovation was scanning at ultra-high field (7 T) at very short echo time. The observed differences are consistent with compromised neurons (NAA, NAAG, Glu and GABA), membrane turnover (PE and tCho), oxidative stress (lower GSH in the OCC), inflammation (mIns), altered energy metabolism (tCho and Glc), and changes in large molecules (Mac). |
| 3412 | Computer #9 |
Frontal GABA concentrations predict cognitive function beyond age-related decline. |
1Aging and Geriatric Research, Institute on Aging, Center for Cognitive Aging and Memory, University of Florida, gainesville, FL, United States, 2Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Kennedy Krieger Institute, FM Kirby Center for Functional Brain Imaging, Baltimore, MD, United States, 4Department of Radiology, University of Calgary, Calgary, AB, Canada, 5CAIR Program, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AB, Canada, 6Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, 7Department of Biostatistics, University of Florida, Gainesville, FL, United States, 8Brain Rehabilitation and Research Center, Malcom Randall Veterans Affairs Medical Center, Gainesville, FL, United States |
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GABA levels measured with MRS have been associated with performance in numerous sensory and attention domains. Here we demonstrate in a healthy aging cohort that frontal GABA levels are predictive of general cognitive function. Furthermore, the previously reported age-related decrease in GABA levels continues into advanced age. |
| 3413 | Computer #10 |
Reduced White Matter Integrity in Cognitively Normal HFE Mutation Carriers |
1Neurosurgery, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, 2Radiology, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, 3Neurology, The Pennsylvania State University - College of Medicine, Hershey, PA, United States |
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Mutations associated with iron dysregulation in the brain include the H63D and C282Y HFE missense mutations and transferrin C2 mutation, all of which have been associated with development of neurodegenerative diseases. Diffusion tensor metrics were further utilized to investigate the relationship between HFE/transferrin mutations and myelin integrity more precisely. The MRI data presented here demonstrate that cognitively normal H63D/C282Y HFE and transferrin C2 carriers have diffusivity changes in white matter compared to wild-type subjects. The observation that these alterations are located in late-myelinating frontal areas is hypothesized to be related to increased susceptibility within this region of HFE/Tf mutation carriers. |
| 3414 | Computer #11 |
The Relationship between White Matter Structure and Clinical Behavior in Different APOE Genotypes: A Preliminary Study in Cognitively Intact Elderly. |
1Radiology, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China, People's Republic of |
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The purpose of this research was to study the relationship of white matter hyperintensities (WMH) with cognitive performance in healthy elderly with different APOE genotypes. In total, 158 subjects were separated into 3 groups (ε2 carriers, ε4 carriers and ε3 homozygotes). Group differences of regional WMH volume were calculated. Subsequent correlation analysis between regional WMH burden and behavior data was performed. Detrimental effect of APOE ε4 allele on white matter structure was found while no protective effect of APOE ε2 was observed; WMH volume was significantly correlated with processing speed and executive ability, especially in APOE ε4 carriers. |
| 3415 | Computer #12 |
Longitudinal relationship between cerebrovascular reactivity and processing speed in young and elderly individuals |
1Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2China Medical University, Taichung, Taiwan, 3University of Texas at Dallas, Dallas, TX, United States, 4University of Texas Southwestern Medical Center, Dallas, TX, United States |
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Processing speed is a fundamental building block of cognition that declines reliably with age. Therefore, the goals of this study were to examine whether changes in cerebrovascular reactivity (CVR) to CO2 inhalation, a marker of cerebrovascular function, is associated with changes in processing speed. the results showed that, In elderly, but not young individuals, the rate of change in CVR over four years predicted decline in processing speed, indicating that declines in vascular brain health contribute to changes in the information processing speed in older but not young and middle-aged adults. |
| 3416 | Computer #13 |
Development and Aging of Superficial White Matter Myelin from Young Adulthood to Old Age: Mapping by Vertex-Based Surface Statistics (VBSS) |
1Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States, 2Department of Radiology, University of Illinois at Chicago, Chicago, IL, United States, 3Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States |
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Using Magnetization transfer imaging (MT) and innovative multimodal analysis approach, the current study vertexwise mapped age-related changes of superficial white matter (SWM) from young adulthood to old age (30-85 years, N = 66). Results demonstrated regionally selective and temporally heterochronologic changes of SWM MTR with age, suggesting that myelin change in SWM occurs at varied paces across the cortex. SWM MTR regions including the rostral middle frontal and parahippocampus followed inverted U-shaped trajectories, with protracted maturation till age 40-50 years and accelerating demyelination after age 60 years, while the primary motor, somatosensory and auditory SWM regions did not show age-related deterioration. |
| 3417 | Computer #14 |
The relationship between White Matter Hyperintensities volume and cognition in normal ageing women |
1The University of Melbourne, Melbourne, Australia, 2Department of Radiology, Royal Melbourne Hospital, Melbourne, Australia, 3Department of Medicine, The University of Melbourne, Melbourne, Australia |
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White Matter Hyperintesities (WMH) lesions on brain magnetic resonance imaging (MRI) are common findings in elderly people and contribute to cognitive impairments. Here we examine volumetric MRI measures of WMH volume in relation to neuropsychological measures of episodic memory, executive function, semantic memory and visuospatial abilities in 116 elderly women, their mean age 69 years. Linear regression analysis showed that greater WMH volume was correlated with lower performance on tests involving measures of executive function and visuospatial abilities. These results help elucidate the pathological process leading to cognitive decline in ageing. |
| 3418 | Computer #15 |
Normal aging effect on commissure fibers assessed with template-based tractography |
1Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan, 2Department of Life Science, National Taiwan University, Taipei, Taiwan, 3Institute of Statistical Sciences, Academia Sinica, Taipei, Taiwan, 4Department of Psychology, National Taiwan University, Taipei, Taiwan, 5Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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This study used template-based diffusion spectrum imaging (DSI) tractography to analyze the microstructural integrity of commissure fiber tracts, and applied functional data statistics to analyze the age effect on the tract integrity. The anterior commissure fibers were highly sensitive to the aging effect across the lifespan. The poster commissure fibers became sensitive to the aging effect after 60 years old. In contrast, the age effect of poster commissure fibers appears to occur after age of 60 years old. In conclusion, our study provides evidences for specific degenerative patterns of the commissure fibers tracts in normal ageing which may serve as a useful reference for neurodegenerative diseases. |
| 3419 | Computer #16 |
Coupled changes in hippocampal integrity and cognitive ability in later life |
1Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom, 2Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, Edinburgh, United Kingdom, 3Department of Psychology, University of Edinburgh, Edinburgh, United Kingdom |
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We tested whether there were coupled changes in hippocampal volume, T1, MTR, FA and MD and three broad cognitive domains (Verbal Memory, Working Memory, and Speed) in a large sample of community-dwelling non-demented adults at 73 and 76 years of age. Hippocampal volume, FA, MTR and T1 declined from age 73 to 76, while MD increased with age. Higher baseline MD was correlated with steeper cognitive decline in all three cognitive measures, but individuals with higher MD increases (i.e. more apparent deterioration in tissue integrity) also tended to show increases in Working Memory. |
| 3420 | Computer #17 |
White Matter Structural Integrity and Cerebral Arterial Pathology in Normal Aging |
1Department of Radiology, Albert Einstein College of Medicine, Bronx, NY, United States, 2Departments of Neurology and Public Health Sciences, University of Miami Miller School of Medicine, Miami, FL, United States, 3Saul R Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, NY, United States, 4Saul R Korey Department of Neurology and Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, United States |
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Normal aging is associated with changes both in micro-structure of white matter of the brain and in cerebral vasculature. We test the hypothesis that these processes are related by examining the association between fractional anisotropy (a diffusion tensor imaging measure of structural integrity) and pulsitility index (a transcranial Doppler ultrasound measure of abnormal arterial flow) in 70 years old and older adults free of stroke and dementia. We identified clusters of significant correlations between the measures, supporting this hypothesis. |
| 3421 | Computer #18 |
Metabolic changes upon supervised aerobic exercise in old adults monitored with 1H MRSI. |
1Neuroradiology, Goethe-Universität Frankfurt, Frankfurt, Germany, 2Brain Imaging Center, Goethe-Universität Frankfurt, Frankfurt, Germany, 3Institute of General Practice, Goethe-Universität Frankfurt, Frankfurt, Germany, 4Institute of Sport Sciences, Goethe-Universität Frankfurt, Frankfurt, Germany |
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In an interventional study changes in metabolic profiles (NAA/tCr, NAA/tCho) upon aerobic exercise were studied comparing two subgroups of volunteers who performed/not-performed supervised aerobic exercise. We observed a difference between both groups which can mainly be assigned to increased NAA/tCho in the group performing exercise. |
| 3422 | Computer #19 |
Age-related variability of functional connectivity in the basal ganglia in healthy elderly subjects and its implications for research in Parkinson’s disease |
1FMRIB centre, University of Oxford, Oxford, United Kingdom, 2Department of Psychiatry, University of Oxford, Oxford, United Kingdom, 3Department of Informatics, Technische Universität München, München, Germany, 4Department of Epidemiology and Public Health, University College London, London, United Kingdom |
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This exploratory study aims to identify factors that may account for variability in functional connectivity within the basal ganglia resting state network (BGN) in healthy subjects, to help the development of an imaging biomarker for Parkinson’s disease. To this purpose we explored the relationship between functional connectivity measures derived from resting state fMRI and several demographic, behavioral and motor variables, in a large population-based sample of healthy elderly subjects, participating in the Whitehall II imaging sub-study. |
| 3423 | Computer #20 |
Aging Increases Markers of Inflammation and Alters Brain-Gut Interactions |
1Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, United States, 2University of Kentucky, Lexington, KY, United States, 3Lexington, KY, United States, 4Physiology, University of Kentucky, Lexington, KY, United States |
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Aging is the perhaps the greatest risk factor for the development of numerous health concerns, namely neurological diseases such as Alzheimer’s Disease (AD). Recently, certain variations in the gut microbiota have been implicated in the development of neurological disease. We hypothesize that alterations of the gut microbiome from age may cause dysregulated brain-gut communication, promoting inflammation and ultimately, disease. Indeed, our preliminary data found old mice to have a distorted gut microbiota, decreased cerebral blood flow and cognitive deficits, and distinct levels of certain brain metabolites than the young mice. |
| 3424 | Computer #21 |
The impact of HPG-axis activation to the brain morphometry: a combined surface-based and voxel-based study |
1Department of Radiology, Second Affiliated Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China, People's Republic, Wenzhou, China, People's Republic of, 2Department of Radiology, Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, Sichuan, China, People's Republic of China, Chengdu, China, People's Republic of |
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We investigated the impact of HPG-axis activity on brain morphometry. A total number of 52 subjects were recruited and scanned structural MRI.HPG-axis activated girls had less cortical thickness in the left inferiorparietal relative to comparison subjects. Meanwhile, gray matter volume was greater in the left precuneus in the focused group, relative to the control group. We found a positive correlation between circulating FSH and volume after excluded one outlier. This study demonstrates that there is some puberty-related maturation of the brain morphometry that is not confounded by age in the earlier stage of puberty. |
| 3425 | Computer #22 |
Visceral Adiposity, Inflammation and Cortical Thickness in Midlife |
1Psychology, University of Texas Austin, Austin, TX, United States, 2Kinesiology, University of Texas Austin, Austin, TX, United States |
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The number of individuals classified as obese or overweight has doubled in the last two decades . In addition to documented effects of obesity on physical health, obesity is also associated with significantly deleterious effects on the brain, including increased risk for dementia. It has been hypothesized that the negative effects of obesity on central nervous system functioning are driven by visceral fat, which is metabolically active. However, the mechanisms behind this relationship are poorly understood. Here, we propose to directly test the role of systemic inflammation as a mediator of the relationship between visceral fat and brain structure in middle aged adults |
| 3426 | Computer #23 |
Distinguishing Between Different Aging-Related Cognitive Impairments Using GABA and Glx |
1First Central Clinical College, Tianjin Medical University, Tianjin, China, People's Republic of, 2Tianjin, China, People's Republic of, 3Beijing, China, People's Republic of |
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Several previous studies have tried to use MRS to investigate changes in brain function. In this study, we used a MEGA-PRESS sequence to measure the GABA and Glx concentration of normal controls, normal elderly controls, and patients with mild cognitive impairment and Alzheimer's disease. In ACC, the Glx showed significant differences between each groups, and the GABA showed significant aging effects in normal subjects. |
| 3427 | Computer #24 |
Diabetes Mellitus Alters Brain Iron Metabolism in Cognitive Impaired Patients: Quantitative Susceptibility Mapping (QSM) Study |
1Department of Radiology, Konkuk University School of Medicine, Seoul, Korea, Republic of, 2Department of Neurology, Konkuk University School of Medicine, Seoul, Korea, Republic of |
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We found that the presence of DM is not associated with vacular risk factors on imaging and brain volumes, but associated with decreased susceptibility in left thalamus. Our results indicate that there may be a region-specific alteration of iron accumulation and iron metabolism in patients with both AD and DM. |
| Exhibition Hall | Tuesday, May 10, 2016: 14:30 - 15:30 |
| 3428 | Computer #25 |
Does reduced FOV Diffusion Weighted Imaging inherently yield lower ADC ? |
1Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States, 2Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, United States, 3Department of Radiology, University of Michigan Health System, Ann Arbor, MI, United States, 4Applied Physics Division, National Institute of Standards and Technology, Boulder, CO, United States, 5Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, United States |
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The benefits of reduced field-of-view (rFOV) imaging with the single-shot echoplanar diffusion sequence such as lower distortion and better discrimination of tumor from benign tissue have been demonstrated in several anatomies. In most of these published works, lower ADC was reported using rFOV compared to the standard full FOV (fFOV) method, irrespective of the technique by which rFOV was achieved. In this work we conducted controlled experiments in 3 phantoms to avoid some of the confounding factors present in vivo and investigated if there is a systemic underestimation of ADC in rFOV DWI compared to fFOV DWI. |
| 3429 | Computer #26 |
Diffusion Tensor Imaging of the Cervical and Thoracic Spinal Cord in Pediatric Subjects using an inner FOV 2D RF pulse sequence. |
1Department of Radiology, Thomas Jefferson University, Philadelphia, PA, United States, 2Department of Radiology, Temple University, Philadelphia, PA, United States, 3Department of Occupational Therapy, Thomas Jefferson University, Philadelphia, PA, United States, 4Biostatistics Consulting Center, Temple University School of Medicine, Philadelphia, PA, United States, 5Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany |
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This is the first study in pediatric subjects investigating the DTI values and it’s reproducibility along the entire cervical and thoracic spinal cord (SC). DTI data was acquired from 22 typically developing (TD) children and 15 patients with spinal cord injury (SCI) using an inner field-of-view DTI sequence. Regions of interest were manually drawn on whole cord at every axial slice along the cervical and thoracic SC. Fractional anisotropy and radial diffusivity values were significantly different between TD and SCI suggesting that these appear to be the most sensitive parameter in assessing the state of SC in chronic phase of SCI. This study demonstrates that DTI has a potential to be used as an imaging biomarker for evaluating the extent of injury, which may be useful to prognosticate as well as monitor patients with SCI |
| 3430 | Computer #27 |
Time-dependent diffusion for assessment of treatment response in GL261 murine glioma model |
1Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, United States |
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In this study, we investigate the feasibility of using the recently proposed diffusion MRI method, POMACE (Pulsed and Oscillating gradient MRI Assessment of Cell size and Extracellular space) for characterization of tissue changes induced by chemotherapy. Surface-to-volume ratio (S/V), cell size (Rcell) and extracellular space volume fraction (ECS) are estimated prior to and after 5FU and bevacizumab treatment in GL261 murine glioma model. Preliminary results indicate an early ECS decrease two days after 5FU/bevacizumab administration. By combining OGSE and PGSE, POMACE provides non-invasive and quantitative metrics regarding tumor microstructure that can be applied to evaluate treatment response. |
| 3431 | Computer #28 |
Diffusion Tensor Imaging and Neuropsychological Study: Pilot Findings in HIV Adults |
1Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, 2UCLA School of Nursing, University of California at Los Angeles, Los Angeles, CA, United States, 3Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA, United States |
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Our current study examined whether neuroimaging abnormalities in HIV infected adults are associated with neuropsychological changes as measured by diffusion tensor imaging (DTI) and HIV Dementia scale (HDS). Several brain regions demonstrated significantly decreased values of fractional anisotropy and mean diffusivity. Also there was a significant decline of HDS scores observed in the construction abilities of HIV infected adults compared to healthy controls. This study indicates that DTI is a sensitive tool for correlating neuroanatomic pathologic features with specific cognitive deficits in patients with HIV infection. |
| 3432 | Computer #29 |
Temporal evolution of diffusion indices in white matter and grey matter of macaque brains with ischemic stroke |
1Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States, 2Department of Radiology, School of Medicine, Emory University, Atlanta, GA, United States, 3Department of Psychiatry and Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA, United States, 4Atlanta Veterans Affairs Medical Center, Decatur, GA, United States |
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In the present study, adult macaque monkeys were utilized to characterize the temporal changes of DTI-derived diffusion indices in grey matter (GM) and white matter (WM) after ischemic stroke. Our reults showed that mean diffusivity (MD), radial diffusivity (RD) and axial Diffusivity (AD) decreased significantly in GM and WM immediately post stroke while fractional anisotropy (FA) remained unchanged until 48-hour post stroke. The results demonstrate the sensitivity and robustness of MD, AD and RD to access the ischemic injury of GM and WM during hyperacute stroke, and also reveal the temporal evolutiom of the WM and GM microstructure following stroke onset. |
| 3433 | Computer #30 |
Clinical Evaluation of Simultaneous Multi-Slice Diffusion-weighted Magnetic Resonance Imaging of the Prostate |
1Diagnostic and Interventional Radiology, University of Tuebingen, Tuebingen, Germany |
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To evaluate the clinical performance of simultaneous multi-slice (sms) diffusion-weighted imaging (DWI) of the prostate. A prototype sms-DWI sequence was utilized and compared to conventional DWI sequences. Sms acquisition is based on the recently introduced principle of simultaneously exciting and acquiring multiple slices by a single radiofrequency (RF) pulse, thus accelerating image acquisition directly by the number of simultaneously excited slices (MB-factor). Image analyses revealed similar image quality and lesion detection as compared to conventional DWI sequences at a substantially decreased acquisition time. Sms-DWI seems a valuable alternative to conventional DWI sequences for prostate imaging. |
| 3434 | Computer #31 |
Comparison of six different diffusion weighted MRI models in pancreatic cancer patients |
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Radiation Oncology, Academic Medical Center, Amsterdam, Netherlands, 3Medical Oncology, Academic Medical Center, Amsterdam, Netherlands, 4Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 5Internal Medicine, Academic Medical Center, Amsterdam, Netherlands |
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We compare the performance of six models for diffusion weighted MRI (DWI) data signal intensity as a function of b-values. We obtained three DWI-datasets spread over two sessions from 9 pancreatic cancer patients. To characterize the fit parameters’ sensitivity to abnormalities, we compared the difference in fit parameter values between tumorous and healthy tissue. To characterize repeatability, we obtained the coefficient of variation. Every model had exactly one parameter that was significantly sensitive to tumorous tissue (p<0.05). From these parameters, the most sensitive parameter was f2 from the tri-exponential model, whereas the best repeatable measure was the ADC from the mono-exponential model. |
| 3435 | Computer #32 |
Intravoxel incoherent motion analysis of renal allograft diffusion with clinical and histopathological correlation in pediatric kidney transplant patients |
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Department of Pediatrics, University of California, San Francisco, San Francisco, CA, United States, 3Department of Pathology, University of California, San Francisco, San Francisco, CA, United States, 4GE Healthcare, Menlo Park, CA, United States |
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This study investigated the use of intravoxel incoherent motion (IVIM) analysis for characterizing diffusion in renal allografts of pediatric transplant recipients. Patients were separated into two groups according to whether or not a renal allograft biopsy resulted in a change in clinical management. Patients requiring a change in management (i.e., increase in immunosuppression) showed statistically significant differences in tissue diffusivity in the region of the biopsy relative to those that did not require any change. These results suggest IVIM analysis may be a useful non-invasive tool for guiding clinical management of pediatric kidney transplant patients. |
| 3436 | Computer #33 |
Tract-profiling and bundle statistics: a test-retest validation study |
1Computer Science, Université de Sherbrooke, Sherbrooke, QC, Canada |
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Tractometry is a hot topic in population analysis that combines diffusion MRI metrics along white matter bundles. Using a dataset of 11 healthy subjects with 3 different acquisitions collected within the same week, and a state of the art processing pipeline that removes outliers and splits bundles in separate parts by computing their centroid, we perform a test-retest study which validates that tractometry results are reproducible in terms of shape, volume, average metric value, and tract profiles. |
| 3437 | Computer #34 |
Methodological considerations on graph theoretical analysis of structural brain networks |
1iMinds-Vision Lab, Department of Physics, University of Antwerp, Wilrijk (Antwerp), Belgium, 2Ghent University-iMinds/Image Processing and Interpretation, Ghent, Belgium, 3Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands |
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We studied the reproducibility of whole-brain structural brain connectivity networks reconstructed with constrained spherical deconvolution based probabilistic fiber tractography. Our main finding is that a low spherical harmonics order decreases the reproducibility of graph measures in connectomics. This is most likely caused by the wider peaks in the fiber orientation distributions, which increase the variation in orientations sampled by the tractography algorithm. Based on our observations, we recommend using spherical harmonics decomposition with an order of at least eight whenever the data allows so. In addition, threshold value was important for binary networks, and some network properties were highly intercorrelated. |
| 3438 | Computer #35 |
Diffusion-Weighted Hyperpolarized 13C-Urea in a Murine Model of Liver Fibrosis |
1Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2Department of Pathology, University of California San Francisco, San Francisco, CA, United States, 3Liver Center, University of California, San Francisco, San Francisco, CA, United States, 4Department of Medicine, Division of Gastroenterology, University of California San Francisco, San Francisco, CA, United States |
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Diffusion weighted MRI has been widely used to measure the movement of water molecules and study tissue microstructure in order to characterize both diffuse and focal liver disease. In liver fibrosis, for instance, increased collagen formation is associated with restricted diffusion of water. However, the majority of water within the liver is either in the vascular or intracellular space, making the diffusion of water a potentially poor marker for fibrosis, which is an extracellular process. Here, we investigated applying diffusion-weighted MRI with an exogenously injected extracellular agent, hyperpolarized 13C-urea, as a potentially more sensitive probe of the extracellular space in the liver in a mouse model of liver fibrosis induced with CCl4. |
| 3439 | Computer #36 |
Diffusion parameters derived from multi b-value DWI-data as surrogate marker for kidney function |
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Radiation Oncology, Academic Medical Center, Amsterdam, Netherlands, 3Internal Medicine, Academic Medical Center, Amsterdam, Netherlands, 4Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
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In this study, we show the potential of the tri-exponential intravoxel incoherent motion (IVIM) model parameters as surrogates for kidney function. We show (n=8) that f1, f2 and D (fit parameters) changed as function of angiotensin-II dose (0, 0.3, 0.9 and 3 ng/kg/min). The changes in f1 and f2 correlated (correlation coefficient r=0.42 and -0.62; p=0.01 and p<0.001) to changes in effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) deduced from a 125I-thalamate and 131I-hippuran clearing test. Finally, we showed (n=6) high inter-session and intra-session repeatability with coefficients of variation below 15% for all fit parameters. |
| 3440 | Computer #37 |
Inter-modality correlation of prostatic microenvironmental tissue stiffness and water diffusivity using quantitative functional imaging techniques. |
1Radiotherapy & Imaging, The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London, United Kingdom, 2The Institute of Cancer Research, London, United Kingdom, 3Oncogenetics, The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, London, United Kingdom |
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Location-matched ROI analysis of tissue stiffness (SWE) and water diffusivity (ADC) in 9 normal prostates demonstrated that both techniques can adequately differentiate between peripheral and transitional zonal microenvironments, and that there is a weak negative correlation between tissue stiffness and water diffusivity in the peripheral zone. This suggests that factors such as microvascularity, cell size, extracellular matrix and macromolecules may have a differential effect on tissue stiffness and diffusivity. Transitional zone stiffness is too heterogeneous to demonstrate significant inter-modality correlation. |
| 3441 | Computer #38 |
Dependence of DTI Measures on SNR in a Multicenter Clinical Trial |
1Cleveland Clinic, Cleveland, OH, United States, 2Barrow Neurological Institute, Phoenix, AZ, United States |
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The dependence of DTI metrics on SNR was investigated in a longitudinal multicenter clinical trial. We presented a combined simulation and experimental analysis of the effect of SNR on DTI measures using 27 scanners over 15 months. Although the dependence of DTI measures on SNR is different for each type of scanner, we demonstrate the inverse relation between mean diffusivity and SNR and FA decreasing slightly with SNR. A sufficient SNR is essential for a reliable estimation of DTI parameters generally and the dependence of DTI measures on SNR should be accounted for or corrected when comparing results among scanners. |
| 3442 | Computer #39 |
The effect of brain microbleeds on the structural brain network after stroke |
1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong, 2Department of Bio-Medical Imaging, University of Malaya, Kuala, Malaysia, 3Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong |
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To explore the influences of brain microbleeds (BMBs) on structural brain network in stroke patients, we used DTI-based tractography and brain network analysis to investigate the brain structural network configuration in stroke patients with and without BMBs. Our results demonstrated disrupted balance between integrated and segregated process in global network, and enhanced specialized functions in stroke patients with BMBs. These findings suggested that the presence of BMBs is related to a disturbed brain network organization with imbalanced integrated and segregated information process ability, and brain network analysis is a sensitive tool to assess the impaired cognition caused by cerebral small vessel disease. |
| 3443 | Computer #40 |
DTI Association with Working Memory and Speed in Cognitive Network Pathways |
1St Jude Children's Research Hospital, Memphis, TN, United States |
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We investigate the relationship of structural diffusion tensor imaging (DTI) metrics with working memory and decision speed performance in children treated for acute lymphoblastic leukemia (ALL). We built a core neurocognitive network including a central executive network, a salience network, and subcortical cortex based on previous fMRI findings. We generated structural connectivity pathways based on high-resolution DTI data from the human connectome project, and applied those in ALL patients to quantify DTI measures in each pathway. We found that DTI measures in most pathways were significantly associated with working memory and decision speed performance suggesting an essential structural neurocognitive network. |
| 3444 | Computer #41 |
Clinical Application of Simultaneous Multi-Slice DWI: A Multi-Body-Part Comparison with Standard EPI DWI |
1First Central Clinical College, Tianjin Medical University, Tianjin, China, People's Republic of, 2Tianjin First Central Hospital, Tianjin, China, People's Republic of, 3MR Collaborations NE Asia, Siemens Healthcare, Shanghai, China, People's Republic of, 4MR Collaborations NE Asia, Siemens Healthcare, Beijing, China, People's Republic of |
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Applying simultaneous-multi-slice EPI (SMS EPI) sequences in diffusion-weighted imaging (DWI) can reduce scanning time greatly, but its clinical-routine image quality in different body parts has not been broadly tested. This study compared multi-site DWI images acquired with a prototype SMS EPI sequence with those acquired with a traditional EPI sequence, computed SNR and CNR and conducted paired t-test. The results show there are no significant differences of SNR and CNR between the two kinds of sequence (p>0.05). When the SMS EPI sequence was applied to the clinical DWI examination, it not only reduced scanning time, but also kept the SNR, CNR in the same level as standard EPI. The SMS sequence was able to satisfy the requirements of clinical disease diagnosis. |
| 3445 | Computer #42 |
Altered social communication network in boys with autism spectrum disorder |
1Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan, 2Department of Psychiatry, National Taiwan University College of Medicine, Taipei, Taiwan |
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Impaired social communication skills have been consistently reported in autism spectrum disorder (ASD). We used diffusion spectrum imaging to measure white matter integrity of the social communication network, and investigated its relationships with social communication and social interaction in 62 ASD and 55 typically developing (TD) boys. ASD showed partially reduced white matter integrity of the social communication network as compared to TD. Positive correlations were found between white matter integrity and the social interaction in ASD. In conclusion, altered microstructural property of the social communication network might be a structural correlate of social communication deficits in ASD. |
| 3446 | Computer #43 |
The negative residuals of diffusion kurtosis model: a study on rat brain imaging |
1Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, 2Nuclear Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan |
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The well-behaved residual of a successful fitting model should present as an independent random variable in its histogram, otherwise it will contain structure that is not accounted for in this model. In the study, we found that there are two groups of fitting residuals. And the spatial mapping of these smaller negative pixels reveals that the overestimation of kurtosis model is related to the contribution of vessel signal. Therefore, we proposed a semi-kurtosis model to calculate the restricted diffusion adequately and obtain correct DKI information in these regions with vascular interference. |
| 3447 | Computer #44 |
Spherical Deconvolution of High-Resolution 7T Whole-Head Diffusion Magnetic Resonance Images shows reduced radial anisotropic diffusion in human primary somatosensory cortex |
1Biometry and Medical Informatics, University of Magdeburg, Magdeburg, Germany, 2Siemens Healthcare GmbH, Erlangen, Germany, 3Department of Neurosurgery, University of Magdeburg, Magdeburg, Germany, 4Department of Neurology, University of Magdeburg, Magdeburg, Germany, 5Leibniz Institute for Neurobiology, Magdeburg, Germany |
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Diffusion anisotropy in cortical gray matter (GM) and adjacent white matter (WM) provides microanatomic information about the course of the neuronal structures within GM and when connecting to other brain regions. However, interwoven neuronal fiber orientations and complex folded structures render the analysis difficult. Ultra-high-field diffusion MR imaging (dMRI) overcomes these limitations as the improved SNR allowed acquiring 1.4 mm isotropic voxel with increased diffusion-weighting. Applying constrained spherical deconvolution (1) enabled resolving radial and tangential anisotropic diffusion in cortical gray matter confirming recent reports of reduced radial anisotropy in primary somatosensory cortex as compared to other cortical areas (2). |
| 3448 | Computer #45 |
Investigation of diffusion signal behavior at different diffusion times in a human hepatocellular carcinoma xenograft model |
1Department of Diagnostic Imaging and Nuclear Medicine, Graduate Schoolof Medicine, Kyoto University, Kyoto, Japan, 2The Hakubi Center for Advancer Research, Kyoto University, Kyoto, Japan, 3Department of Systems Science, Graduate Schoolof of Informatics, Kyoto University, Kyoto, Japan |
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The relationship between diffusion time and diffusion parameters in a human hepatocellular carcinoma xenograft mouse model was investigated at 7T. There was an increase in K values and decrease in ADCo values in 27.6ms compared to 9.6 ms. |
| 3449 | Computer #46 |
Altered microstructural integrity of the white matter tracts in strabismus: A systematic tract-specific analysis over the whole brain |
1Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei City, Taiwan, 2Department of ophthalmology, National Taiwan University Hospital, Taipei City, Taiwan, 3Institute of Biomedical Engineering,National Taiwan University, Taipei City, Taiwan, 4Department of Psychology, National Taiwan University College of Science, Taipei City, Taiwan, 5Molecular Imaging Center, National Taiwan University, Taipei City, Taiwan |
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To investigate whether the white matter tracts are altered in patients with strabismus, we used diffusion spectrum imaging to measure microstructural property of 78 major white matter tracts, and compared the property between 12 patients with strabismus adults and 24 matched controls. As compared to the controls, patients showed differences with large effect sizes in the left vertical occipital fasciculus, callosal fibers to bilateral precuneus, callosal fibers to bilateral inferior parietal lobules, and the left superior longitudinal fasciculus I. The altered white matter tracts support the hypothesis of underlying microstructural changes of the visual pathways in strabismus. |
| 3450 | Computer #47 |
Flip Angle Optimization in Diffusion-Weighted Imaging using Simultaneous Multi-Slice Acceleration |
1Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, China, People's Republic of |
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In this study, an automatic optimization scheme was proposed in diffusion-weighted imaging using simultaneous multi-slice (SMS) acceleration to determine an appropriate flip angle based on a short TR, which is capable to obtain similar contrast of a pair of tissue type compared to the one with long TR scan. With this optimization scheme, minimal TR in SMS case is practically achievable and there is no obvious contrast deviation between images from long TR (FA = 900) and short TR (FA < 900). |
| 3451 | Computer #48 |
Investigation of Intravoxel Fiber Configuration Complexity in the Human Heart |
1CREATIS; CNRS UMR 5220; Inserm U 1044; INSA of Lyon; University of Lyon;, Lyon, France, 2School of computer science and technology, Guizhou University, Guiyang, China, People's Republic of, 3School of Computer and Information Technology, Beijing JiaoTong University, Beijing, China, People's Republic of |
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Fiber crossing in the myocardium of the heart is controversial despite some reports on the heart of animals. The purpose of this study is to investigate the fiber configuration complexity in a voxel, such as fiber crossing, in the human heart. We applied two different reconstruction techniques commonly used in high angular resolution diffusion imaging (HARDI) to conventional diffusion tensor imaging (DTI) data of the human heart acquired on clinical MRI system. The results consistently demonstrated that the human myocardium exhibits some complex fiber configurations such as fiber crossing in a voxel. |
| Exhibition Hall | Tuesday, May 10, 2016: 14:30 - 15:30 |
| 3452
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Computer #49 |
Prediction of the development of distant metastases from nasopharyngeal carcinoma using Diffusion-Weighted Imaging |
1Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, Hong Kong, 2Department of Clinical Oncology, The Chinese University of Hong Kong, Shatin, Hong Kong |
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This study evaluated pre-treatment diffusion weighted imaging of primary nasopharyngeal carcinoma for the prediction of patients at risk of distant metastases, based on long-term follow-up for at least 5 years. Analysis was performed of ADC parameters using histogram analysis (ADCmean, ADCskewness and ADCkurtosis), together with stage and volume of the primary tumour and nodes. Multivariate analysis showed pre-treatment ADCskewness, T stage and nodal volume were significant ( p =0.026, 0.022 and 0.005, respectively), distant metastases being more likely in patients with tumours with ADC values skewed toward the higher ADC range, and higher T stage and nodal volume. |
| 3453 | Computer #50 |
Differentiation of prostate cancer in central gland with Histogram analysis of apparent diffusion coefficient |
1Radiology, Fudan university shanghai cancer center, Shanghai, China, People's Republic of, 2MR Research China, GE healthcare, Beijing, China, People's Republic of |
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The diffusion weighted imaging (DWI) is commonly used in the diagnosis of Prostate cancer, but the cancer in Central gland (CG) is considered harder to detected on conventional DWI,but histogram analysis of apparent diffusion coefficient could potentially improve the differentiation of prostate cancer in CG. |
| 3454 | Computer #51 |
Statistical evaluation of bi-exponential IVIM effect in healthy human liver and its dependence on the cut-off b-value for segmented biexponemtial fit |
1Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong, 2Department of diagnostic & interventional radiology, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong, 3Comprehensive Oncology Center, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong |
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The use of IVIM in assessing the microcapillary perfusion and true diffusion has attracted elevating attention. The segmented bi-exponential fitting has been widely adopted to calculate IVIM metrics, in which a cut-off b-value is pre-defined for perfusion and diffusion region separation. This study calculated the corrected Akaike Information Criterion (AICc) for bi-exponential IVIM model in the healthy human liver with varying cut-off b-values and then compared to the AICc for the mono-exponential model. The statistical preference of the bi-exponential model to mono-exponential model was demonstrated based on the lowest AICc. This bi-exponential model preference was independent of the choice of cut-off b-value and ROI location. |
| 3455 | Computer #52 |
Histogram analysis of apparent diffusion coefficient in characterizing solid pancreatic masses |
1Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan |
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This study focused on the potential of ADC histogram analysis on DW imaging to characterize solid pancreatic masses. Among the ADC histogram parameters, the entropy of ADC with every b-value combination showed the highest area under the receiver operating characteristic curve for distinguishing neuroendocrine tumors from pancreatic adenocarcinomas and mass-forming autoimmune pancreatitis. The entropy of ADC might add helpful information in differentiating neuroendocrine tumors from pancreatic adenocarcinomas and mass-forming autoimmune pancreatitis, especially in patients with contraindication to contrast agents or with solid pancreatic masses showing atypical findings at dynamic CT or MRI. |
| 3456 | Computer #53 |
Histogram analysis of apparent diffusion coefficient for non-small cell lung cancer: correlation with pathological grade. |
1Radiology, Kanazawa Medical University, Kahoku, Japan, 2Thoracic surgery, Kanazawa Medical Universiy, Kahoku, Japan |
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The purpose of this study is to investigate the application of histogram analysis of ADC in determining the pathological grade of non-small cell lung cancer (NSCLC). The study included 54 patients and the histogram parameters were correlated with pathological grades. For the parameters that were significantly different between high- and low-grade tumors, ROC curve analysis was performed. The 95th percentile of ADC was the most beneficial parameter for distinguishing high-from low-grade tumors. ADC histogram analysis on the basis of the entire tumor volume is useful for predicting the pathological grade of NSCLC. |
| 3457 | Computer #54 |
The superiority of high b value iZOOM with a Two Dimensional Radiofrequency Pulse (2D RF) Echo Planner Imaging (EPI) Sequence in Prostate Compared with regular ss-EPI DWI at 3.0 T |
1The Department of Radiology, Peking University First Hospital, Beijing, China, People's Republic of, 2Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China, People's Republic of, 3Philips Healthcare, Beijing, China, People's Republic of, 4Philips Healthcare (Suzhou) Co., Ltd (Suzhou), Suzhou, China, People's Republic of, 5Philips research China, Beijing, China, People's Republic of |
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This study aims to assess the clinical feasibility of high b value iZOOM on prostate and to validate whether it is superior to regular DWI at 3.0 T with 58 patients recruited in the study. The scan protocol included iZOOM and DWI with b value of 2000s/mm2. Subjective and objective evaluation was carried out from three aspects: the basic image quality, the display of lesions, and the overall image quality. Our study found that with the same high b value, iZOOM had better comprehensive image quality, less artifact and distortion yet similar contrast compared with regular DWI. |
| 3458 | Computer #55 |
Feasibility of vertebral bone Diffusion Weighted MR Imaging (DWI) for early diagnosis of hepatic osteodystrophy in Primary Sclerosing Cholangitis |
1Diagnostic and Interventional Radiology, University Medical Center Hamburg Eppendorf (UKE), Hamburg, Germany, 2MRI, Philips GmbH, Hamburg, Germany, 3Department of Internal Medicine, University Medical Center Hamburg Eppendorf (UKE), Hamburg, Germany, 4Biochemistry, University Medical Center Hamburg Eppendorf (UKE), Hamburg, Germany |
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Hepatic osteodystrophy is a frequent complication in patients with chronic cholestatic and non-choleatatic liver disease, affecting up to 20-30% of patients [1, 2]. Besides conventional dual x-ray absorbtiometry (DXA) scans, diffusion-weighted MRI (DWI) has been performed for the evaluation of osteoporosis and osteopenia in risk patients. Follow up MRI examinations of PSC patients, to exclude malignancy and identify bile duct stenosis, are frequently performed in clinical routine. The aim of this study was to test the feasibility of add-on DWI sequences during routine examination for the detection of early changes of the bone marrow density (BMD) in comparison to DXA T-score values of the vertebral bone and healthy controls. |
| 3459 | Computer #56 |
Readout-Segmented Echo-Planar Imaging Improves the Image Quality of Diffusion-Weighted MR Imaging in Rectal Cancer |
1West China Hospital, Chengdu, China, People's Republic of, 2Beijing, China, People's Republic of, 3Erlangen, Germany, 4Chengdu, China, People's Republic of |
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Readout-segment EPI (rs-EPI) is a new approach to reduce susceptibility artifacts and blurring in DWI. In this study, we qualitatively and quantitatively compare the images quality of ss-EPI and rs-EPI for rectal cancer DWI |
| 3460 | Computer #57 |
Clinical application of quantitative DWI in the pathological grading of lipid-containing small HCC |
1302 military hospital of China, Bei Jing, China, People's Republic of |
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This study is designed to investigate whether ADC values of lipid-containing small HCC with different pathological grading are the same as well as the correlation of ADC values with the pathological differentiate degree. There was significant difference between low-grade group and moderate-grade group, as well as between low-grade group and high-grade group (P <0.05), and there was obviously significant difference between moderate-grade and high-grade group (p <0.05). Meanwhile, there was moderately positive correlation between ADC value and pathological grading of lipid-containing small HCC (P=0.002, r=0.419) and the coefficient of association was 0.95. This study demonstrated ADC value can distinguish different pathological grading of lipid-containing small HCC, and there is moderately positive correlation between them. |
| 3461 | Computer #58 |
Implementing a fast MR screening protocol for pancreas in patients with mutations of BRCA1 and BRCA2: preliminary data on Diffusion-Weighted Images. |
1Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY, United States, 2Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, United States, 3Global MR Applications and Workflow, GE Healthcare, New York, NY, United States, 4Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, United States, 5Saint Vincent Ferrer High School, New York, NY, United States |
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The aim of the study is the qualitative and quantitative evaluation of Diffusion-weighted images (DWI) with reduced field-of-view (rFOV), that are incorporated into a fast rapid MR pancreas screening protocol (MRpsp). We are developing a fast rapid MRpsp to be performed in carriers of BRCA mutations after a breast MRI, using the built-in body coil of a 3T magnet without repositioning a patient who is in the prone position. 15 patients were scanned. For b-values <100 s/mm2, b=20 s/mm2 DWI had the best contrast-to-noise and signal-to-noise ratios. Among b-values >100 s/mm2, b=250 s/mm2 DWI showed the highest diagnostic information. |
| 3462 | Computer #59 |
Optimization of Direct-coronal Diffusion-weighted Whole Body Imaging with Background Suppression (DWIBS) Using Single-shot Turbo Spin-echo (TSE) at 3T MRI. |
1Department of radiological servece, Tokyo Women's Medical University Hospital, Tokyo, Japan, 2Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women's Medical University Hospital, Tokyo, Japan, 3IS Business Group, Philips electronics japan, Tokyo, Japan |
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Direct-coronal diffusion-weighted whole body imaging with background body signal suppression using single-shot turbo spin-echo (TSE-DWIBS) with b-values of 400, 600, 800, and 1000 mm2/s, and DWIBS using echo-planner imaging (EPI-DWIBS) with b-value of 1000mm2/s were obtained using 3T MR scanner in 5 healthy volunteers. We investigated optimal b-value of TSE-DWIBS and compared image distortions, contrast, signal-to-noise ratio (SNR), and artifacts between TSE-DWIBS and EPI-DWIBS. Image contrast and SNR of TSE-DWIBS with b-value of 800 mm2/s were equivalent to those of EPI-DWIBS with b-value of 1000 mm2/s. TSE-DWIBS had less image distortions and artifacts than EPI-DWIBS. Direct-coronal TSE-DWIBS using 3T MRI can be applied for clinical cases. |
| 3463 | Computer #60 |
Repeatability on diffusion MRI measurements on the different numbers of b values and excitations of the breast and its comparison with lactating breasts |
1Department of Diagnostic Imaging and Nuclear Medicine, Graduate Schoolof Medicine, Kyoto University, Kyoto, Japan, 2The Hakubi Center for Advancer Research, Kyoto University, Kyoto, Japan |
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The effects of different numbers of b values and excitations on the non-Gaussian DWI parameter estimates in the breast of normal volunteers |
| 3464 | Computer #61 |
Zoomed EPI-DWI of the Kidney Using Two-Dimensional Spatially-Selective Radiofrequency Excitation Pulses |
1Radiology, Peking Union Medical College Hospital, Beijing, China, People's Republic of, 2Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany |
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This is the first MR study to evaluate the use of zoomed EPI technology for diffusion-weighted imaging in the kidney. Zoomed diffusion-weighted EPI leads to substantial image quality improvements with reduction of susceptibility artifacts in renal DWI. The combination of the two sequences for renal imaging might be recommended: a c-EPI scan to cover and screen the whole upper abdomen and a z-EPI scan focused on the targeted anatomical structure and suspected lesions. |
| 3465 | Computer #62 |
Non-invasive quantification of prostate cancer using AMICO framework for VERDICT MRI |
1Centre for Medical Image Computing, University College London, London, United Kingdom, 2Signal Processing Lab (LTS5), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3University Hospital Center (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 4Centre for Medical Imaging, University College London, London, United Kingdom |
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The aim of this study is to extend the AMICO framework to the VERDICT model-based diffusion-weighted MRI (DW-MRI) technique and to evaluate its performance to prostate cancer imaging. DW-MRI was acquired for 4 subjects and the VERDICT model was fitted to the data using both fitting procedures. In both cases similar differences in parameter values between tumour and normal tissue were found. The AMICO formulation reduces the computation time for VERDICT and produces parameter maps that are more homogeneous than those obtained with the original fitting. The AMICO formulation reflects the microstructural differences in a clinically practical time. |
| 3466 | Computer #63 |
Assessing micro- and macro-circulation of graft kidneys by using IVIM-DWI and Non-contrast MRA |
1Department of Radiology, Taichung Veterans General Hospital, Taiwan, Taiwan, Taiwan, 2Division of Nephrology, Taichung Veterans General Hospital, Taiwan, Taiwan, Taiwan, 3Division of Urolog, Taichung Veterans General Hospital, Taiwan, Taiwan, Taiwan, 4Department of Electrical Engineering, National Chung Hsing University, Taiwan, Taiwan |
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The goal of the present study was to perform IVIM-DWI and non-contrast MRA of graft kidneys to evaluate the micro- and micro-structural status in 17 patients within 48 hours after transplantation. Five of them had a second scan in six months later. The experimental results suggested that D*, D and f values in IVIM-DWI might considerably be useful in early detection of functional change graft kidneys and non-contrast MRA and PC-MRI could effectively assess patency and flow rates of graft vessels. Combination of both IVIM-DWI and non-contrast MRA would be potentially promising in clinical application for monitoring graft kidneys. |
| 3467 | Computer #64 |
The repeatability of IVIM with fuzzy clustering algorithm in liver imaging |
1Imaging Systems Clinical Science, Philips Healthcare, Beijing, China, People's Republic of, 2Radiology department, Shengjing Hospital of China Medical University, Shenyang, China, People's Republic of |
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Fussy clustering technique (FCM) has been combined with IVIM to increase the stability and reduce the post-processing time of the nonlinear curve fitting in IVIM. Another problem of the widely used bi-exponential IVIM model is its poor repeatability. This work is to assess the repeatability of IVIM with FCM between two scans in healthy liver by calculating the coefficient of variation and the 95% Bland–Altman limits of agreements. Results proved that FCM could improve the repeatability of IVIM, especially for the parameter D*, which was the most unstable among total 3 parameters. |
| 3468 | Computer #65 |
Preliminary Investigation: Gaussian and Non-Gaussian Diffusion Method in Diagnostic Differentiation of Prostate Cancer from Prostatic Hyperplasia |
1The Affiliated Hospital of Dalian Medical University, Dalian, China, Dalian, China, People's Republic of, 2GE Healthcare, MR Research China, Beijing, Beijing, China, People's Republic of |
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Prostate cancer is the second most common cancer for men, and it has high leading cause of cancer death among men. In this study, DKI and DWI MR measurements were performed to investigate the correlation of the MK, Ka, Kr, MD, Da, Dr, FA and ADC values in ROIs of the prostate and benign prostatic hyperplasia. DKI working at present scanning hardware are capable to detect the pathophysiological changes unattainable to conventional MRI techniques. |
| 3469 | Computer #66 |
Diffusion weighted imaging of prostate cancer: mathematical modeling of signal obtained using low b values |
1University of Turku, Turku, Finland, 2Turku University Hospital, Turku, Finland |
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Eighty-one patients with historically confirmed PCa underwent two repeated 3T DWI examinations performed using 14 b-values in the range of 0-500 s/mm2 and diffusion time of 19.004 ms. Various fitting methods for IVIM and mathematical models were evaluated in the terms of fitting quality (Akaike information criteria), repeatability, and Gleason score prediction. Monoexponential model demonstrated the highest repeatability and clinical values in the regions-of-interest based analysis of PCa DWI, b-values in the range of 0-500 s/mm2. |
| 3470 | Computer #67 |
Characterizing breast lesions by Using Mono-exponential, Bi-exponential, and Stretched Exponential Diffusion-weighted MR Imaging and Diffusion Kurtosis MR Imaging |
1Department of Radiology, Ruijin Hospital,Shanghai Jiao Tong University School of Medicine, Shanghai, China, People's Republic of, 2Application Dept, Siemens Healthcare, Shanghai, China, People's Republic of |
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DKI model may provide additional information and improve the characterizing of breast lesions compared with conventional diffusion parameters. The kurtosis and water molecular diffusion heterogeneity index derived from DKI and stretched Exponential DWI may be helpful for the preoperative differentiation of proliferative activity of breast cancer. |
| 3471 | Computer #68 |
Comparative analysis of diffusion models for glioma malignancy grade differentiation |
1TU Dortmund University, Dortmund, Germany, 2Burdenko Neurosurgery Institute, Moscow, Russian Federation |
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Diffusion weighted imaging is very powerful technique allows one to diagnose and differentiate glioma malignancy in vivo. Recently, the non-Gaussian diffusion models exhibited their efficacy in a detection of microsctructure changes for low and high grade gliomas. In this study we perform a comparative analysis of four diffusion models (DTI, DKI, two- and three-compartment models) in ability to provide a quantitative measure of the gliomas malignancy in vivo. |
| 3472 | Computer #69 |
Optimization of Single-shot Turbo Spin-echo Diffusion-weighted Imaging with Parallel Imaging in Healthy Pancreas |
1Diagnostic Imaging and Nuclear Medicine, Tokyo Women's Medical University Hospital, Tokyo, Japan, 2Radiological Service, Tokyo Women's Medical University Hospital, Tokyo, Japan, 3Philips Electronics Japan, Tokyo, Japan |
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We compared the image quality of single-shot turbo spin-echo diffusion-weighted imaging (TSE-DWI) with parallel imaging and conventional echo planar DWI (EPI-DWI) in the pancreas of healthy volunteers. TSE-DWI with a sensitivity encoding factor (SF) of 2, 4, 6, and EPI-DWI with SF2 (b-values = 0, 500, 1000 s/mm2) were obtained using a 3T MRI scanner. Two radiologists evaluated overall image quality, susceptibility artifacts, and aliasing artifacts. TSE-DWI with moderate SF had better image quality than conventional EPI-DWI for a medium b-value because of less susceptibility artifacts. |
| 3473 | Computer #70 |
7T diffusion MRI of the forearm nerves |
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Forensic Medicine, Aarhus University, Aarhus, Denmark, 3Comparative Medicine Lab, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark, 4Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands |
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In this work we present our results obtained at the 7T MRI scanner investigating the nerves in the forearm. We tested two DTI protocols and were able to visualize the median, ulnar and radial nerves with fiber tractography with resolution up to 0.75×0.75×2.0 mm3. We have demonstrated the potential of 7T to identify these nerves and quantify their diffusion characteristics in a reliable way. We expect that the use of high resolution DTI can be beneficial in the investigation of peripheral nervous tissue in the forearm and might aid in identifying changes due to pathology. |
| 3474 | Computer #71 |
Comparison of TSE and EPI for renal DTI |
1Department of Diagnostic and Interventional Radiology, University of Würzburg, Würzburg, Germany |
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Echo-planar imaging (EPI) is usually applied to acquire diffusion-weighted images. While EPI is fast in acquiring an entire image, it brings along distortion artifacts. Turbo spin echo (TSE) acquisitions require more time than EPI, but avoid distortions. Purpose of this study was to compare TSE and EPI for diffusion tensor imaging of the human kidney. We found similar mean diffusivity with EPI and TSE. Fractional anisotropy provides good corticomedullary contrast with both methods TSE and EPI. TSE is a practicable alternative to EPI for diffusion tensor imaging of the kidney. |
| 3475 | Computer #72 |
Imaging bio-markers of Intervertebral disc degeneration by T2 Relaxometry and DTI A prospective Study with Multi parametric Imaging correlation |
1Imaging, Vijaya diagnostics and research, Hyderabad 500020, India, 2Orthopaedic and Spine surgery, Udai orthopaedic Institute, Hyderabad 500020, India, 3Imaging, GH, Hyderabad 500020, India |
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Surgeons want to know Predictive disc health proximal to the level of fusion or intervention. Conventional MR imaging using T2 weighted Imaging is insensitive to early morphological changes with no predictive quantitative biomarker profile of early degeneration. The Thompson scale or the Pfirrmann scale are discontinuous scales fail to demonstrate the Degeneration or regeneration of disc Objectively. Multiparametric Imaging using T2 relaxometry maps,DTI indices namely FA and qualitative FA maps offer both quantitative and qualitative biomarkers for predictive disc health |
| Exhibition Hall | Tuesday, May 10, 2016: 14:30 - 15:30 |
| 3476 | Computer #73 |
Simple and robust cardiac diffusion weighted imaging using single-shot Turbo Spin-Echo with peripheral pulse gating |
1Department of Radioligical Service, Tokyo Women's Medical University Hospital, TOKYO, Japan, 2Department of Diagnostic imaging & Nuclear Medicine, Tokyo Women`s Medical University Hospital, Tokyo, Japan, 3Philips Electronics Japan, Tokyo, Japan |
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We evaluated the feasibility of optimal gating method and imaging parameters for Single-Shot Turbo Spin Echo (ssTSE) diffusion weighted image (DWI). As a result, The Peripheral pulse gating (PPG) synchronization method was significantly higher in visual scoring than that of the ECG synchronization method (p=0.02) and ssTSE-DWI using SENSE-factor 4.0 brought about the best image quality. Refocusing Flip Angle (RFA) tended to be higher in images with higher visual score. Visualizing cardiac DWI was feasible under above conditions. In conclusion, it is expected that ssTSE-DWI using PPG has a possibility to detect abnormal signal from myocardium by non-contrast MRI. |
| 3477 | Computer #74 |
The Study of Vertebral Marrow Microstructure in Healthy Young Adults with Intravoxel Incoherent Motion Diffusion-weighted Imaging |
1The Second Hospital of Shanxi Medical University, Taiyuan, China, People's Republic of, 2GE Healthcare MR Research China, Beijing, China, People's Republic of, 3Center for Magnetic Resonance Research, University of Illinois Hospital &Health Sciences System, Chicago, IL, United States |
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MRI has become preferred over other imaging modalities in evaluating marrow compositions. Although the routine MRI can evaluate the cellularity of marrow according to signal intensity, it’s not quantitative analysis. IVIM provides both diffusion and perfusion quantification using a single imaging study at the same time, without intravenous contrast injection. IVIM has been applied in various diseases, but the application of IVIM in marrow composition is less. As the preliminary study, we will adopt the parameters of IVIM to assess the vertebral bone marrow microstructure, then to investigate gender-related cellular and capillary network of vertebral marrow in healthy young adults. |
| 3478 | Computer #75 |
Corticospinal Tract Distribution in Motor Cortices of Adult Macaque Brains Revealed by High Angular Resolution Diffusion Imaging Tractography |
1Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States, 2Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States |
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Non-human primates mimick most aspects of humans and are widely used in preclinical or medical studies. Understanding the structural connectivity in non-human primate brains can provide essential reference for translational research. The characterization of the corticospinal tracts plays a crucial role in motor function and has been well studied in human brain. However, it remains not fully understood in non-human primates. In this work, high angular resolution diffusion imaging (HARDI) tractography was utilized to evaluate the corticospinal tracts distribution in sub-regions of motor cortices of adult macaque monkeys, and high similarity to prior ex-vivo results was observed. |
| 3479 | Computer #76 |
White matter lesions highly influence group comparison of diffusion tensor imaging metrics |
1Diagnostic Radiology, Clinical Sciences, Lund University, Lund, Sweden, 2Center for Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden, 3Lund University Bioimaging Center, Lund University, Lund, Sweden, 4Department of Medical Radiation Physics, Lund University, Lund, Sweden, 5Clinical Memory Research Unit, Clinical Sciences, Lund University, Malmö, Sweden, 6Neurology, Clinical Sciences, Lund University, Lund, Sweden |
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White matter lesions (WML) are common in cognitively healthy elderly and their presence in a brain region is associated with elevated mean diffusivity (MD) and reduced fractional anisotropy (FA). We compared patients with amnestic mild cognitive impairment (aMCI) to control groups with different prevalence of WML. Our results showed that including subjects with WML in the control group highly influence the outcome of statistical analysis of diffusion tensor imaging (DTI) metrics. We conclude that WML should be taken into consideration when designing and interpreting DTI studies. |
| 3480 | Computer #77 |
Quantitative Diffusion MRI of Hematopoietic Acute Radiation Syndrome using a Minipig Model |
1Radiology, University of Illinois at Chicago, Chicago, IL, United States, 2Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, IL, United States, 3Pharmacology, University of Illinois Medical Center, Chicago, IL, United States, 4Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 5Surgery, University of Illinois Medical Center, Chicago, IL, United States, 6Radiology, Chicago, IL, United States, 7Neurosurgery, University of Illinois at Chicago, Chicago, IL, United States |
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The purpose of this study is to characterize Hematopoietic Acute Radiation Syndrome (hARS) and assess the effect of total body irradiation in a Göttingen minipig model using quantitative diffusion MRI. The minipigs were irradiated at a total dose of either 1.65 Gy (LD30/45 days) or 1.90 Gy (LD70/45 days). The animals underwent diffusion MRI scans prior to and again at 8, 15, or 22 days following irradiation. The consistent diffusion value prior to irradiation and the significant changes post-irradiation, both observed in this study, suggest that quantitative diffusion MR can be a viable marker for studying the effect of total body irradiation. |
| 3481 | Computer #78 |
White matter microstructure among perinatally HIV-infected youth: A diffusion tensor imaging study |
1Radiological Sciences, UCLA School of Medicine, Los angeles, Los Angeles, CA, United States, 2Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, United States, 3Infectious disease-Pediatrics, Miller’s Children’s Hospital of Long Beach, Long Beach, CA, United States, 4Pediatrics, UCLA School of Medicine, Los angeles, Los Angeles, CA, United States, 5Pediatrics, Children’s Hospital Los Angeles, Los Angeles, CA, United States, 6Radiology, Harbor-UCLA Medical Center, Torrance, CA, United States |
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DTI was used to derive in vivo tissue status measurements of subcortical brain regions that are vulnerable to injury in perinatally HIV-infected youths. Quantitative measurements, including the mean diffusivity (MD), fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD) were determined in of the whole brain in 12 well-characterized HIV youths and in 12 healthy control subjects. We observed widespread brain regions with increased AD values in perinatally HIV-infected youths compared to healthy controls, indicating axonal changes. We also observed increased FA, MD and RD. To confirm these findings a correlation study with neurodevelopement and neurocognitive changes as well as ART effect is needed. Understanding the impact of HIV disease severity on white matter integrity provides potentially useful clinical tools for evaluating ART efficacy during a dynamic period of brain development. |
| 3482 | Computer #79 |
Intravoxel incoherent motion diffusion weighted imaging in evaluating the radio-sensitivity of nasopharyngeal carcinoma xenografts |
1Radiology, Fujian Provincial Cancer Hospital, Fuzhou, China, People's Republic of, 2Radiation Oncology, Fujian Provincial Cancer Hospital, Fuzhou, China, People's Republic of |
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In this present study, by applying the special mouse coil(4 channel), IVIM-DWI with 14 b-factors(0~1000s/mm2) was successfully conducted on nude mice with different radio-sensitive NPC xenografts(CNE-1 and CNE-2) during the course of fractional radiations. The IVIM-DWI parameters of xenografts were found to change characteristically after fractional radiations and were significantly different between different radio-sensitive NPC xenografts, and their corresponding changes also behaved significant correlations with the pathological features of NPC xenografts. Thus, it is suggested IVIM-DWI parameters be valuable in evaluating the micro-structures and radio-sensitivity of NPC xenografts. |
| 3483 | Computer #80 |
Combining Intravoxel Incoherent Motion Model and Reduced FOV for Evaluation of Single Renal Diffusion and Perfusion |
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China, People's Republic of, 2College of Engineering, Peking University, Beijing, China, People's Republic of, 3Philips Healthcare, Suzhou, China, People's Republic of, 4Department of Radiology, Peking University First Hospital, Beijing, China, People's Republic of |
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The sequence most commonly used in renal DWI is based on single-shot echo-planar imaging (SS-EPI), which is prone to artifacts and distortions related to susceptibility and eddy currents. Reducing these artifacts and distortions in SS-EPI generally requires a reduced field of view (rFOV) in the phase-encoding direction and/or reduced spatial resolution. To resolve these problems, a 2D rFOV-DWI sequence was introduced for imaging and further IVIM modeling. Compared with conventional full-FOV single-shot DWI techniques, rFOV-DWI methods generally produced images of superior quality. With the application of IVIM model, it is possible to evaluate single renal diffusion and perfusion simultaneously. |
| 3484 | Computer #81 |
Super-Resolution Track Density Imaging of 1.4 mm isotropic 7T Whole-Brain Diffusion Magnetic Resonance Images |
1Biometry and Medical Informatics, University of Magdeburg, Magdeburg, Germany, 2Siemens Healthcare GmbH, Erlangen, Germany, 3Department of Neurosurgery, University of Magdeburg, Magdeburg, Germany, 4Department of Neurology, University of Magdeburg, Magdeburg, Germany, 5Leibniz Institute for Neurobiology, Magdeburg, Germany |
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Track-density imaging (TDI) is a method to generate super-resolution images from fiber-tracking data (1). Here, we applied this technique to 1.4 mm isotropic 7T whole brain diffusion MR imaging data (dMRI). Besides the well-known large and medium-sized fiber tracts the high resolution of the data allowed visualizing the complex interwoven courses of fiber tracts in the cerebellar-pontine angle as well as showing parts of the trigeminus nerve. Combining TDI with high-resolved diffusion data has a great potential for analyzing the anatomy in vivo of brain structures across different scales as well as the neuronal connectome throughout the whole brain. |
| 3485 | Computer #82 |
Multi-Center Validation of an Acetone-D2O Quantitative Diffusion Phantom |
1Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 2Radiology, University of Wisconsin-Madison, Madison, WI, United States, 3Radiology, Duke University, Durham, NC, United States, 4Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States, 5Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 6Medicine, University of Wisconsin-Madison, Madison, WI, United States, 7Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States |
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A recently proposed acetone-D2O phantom, which has ADC tunable over the entire physiological range, has shown promise for the development and quality assurance of quantitative diffusion MRI. In this study, this phantom was shipped between three sites with different MRI vendors to demonstrate consistent diffusion quantification across imaging protocols, platforms, and field strengths. The results demonstrated consistent ADC measurements across sites/vendors, field strength, choice of b-values, intra-exam and inter-exam repetition. In conclusion, the acetone-D2O phantom is a promising tool for future multi-center validation and quality assurance of quantitative diffusion MRI techniques. |
| 3486 | Computer #83 |
Measuring diffusion time dependence of pseudo-diffusion using flow compensated pulsed and oscillating gradient sequences |
1Radiology, Johns Hopkins University School of Medicine, BALTIMORE, MD, United States, 2Radiology, New York University School of Medicine, New Yourk, NY, United States |
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Intravoxel incoherent motion (IVIM) in the capillaries reflects capillary geometry and flow velocity, which may be probed by diffusion MRI measured at varying diffusion times. In this study, we employed flow-compensated pulsed and oscillating gradient sequences to investigate the diffusion time dependence of pseudo-diffusion in the mouse brain with diffusion times ranging from 2.5 ms to 40 ms. We used a simplified IVIM model to characterize the pseudo-diffusion compartment and flow compartment based on the relation between capillary segments and diffusion time/distance. Our results clearly demonstrated diffusion time dependence and suggested that the pseudo-diffusion fraction increased with increasing diffusion time. |
| 3487 | Computer #84 |
Diffusion weighted imaging of prostate cancer xenografts: comparison of bayesian modeling and independent least squares fitting |
1University of Turku, Turku, Finland, 2A.I. Virtanen Institute for Molecular Sciences, Kuopio, Finland |
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Tumor growth in mice preclinical prostate cancer model (human prostate cancer cells, PC-3) was followed for 4 weeks by weekly DWI in control group (n=10) and treatment group (n=9) receiving Docetaxel. DWI data sets were acquired using 15 b-values in the range of 0-500s/mm2 and 12 b-values the range of 0-2000 s/mm2. The DWI signal decays were fitted using monoexponential, biexponential, kurtosis and stretched exponential models/functions. Bayesian shrinkage prior method and independent least squares fitting have been applied and fitting quality evaluated by corrected Akaike Information Criteria. Bayesian modeling improved quality of DWI parametric maps derived using high b-value DWI data sets. Our result does not support the use of biexponential, kurtosis and stretched exponential models/functions for low b value DWI data sets of PC-3 mice preclinical prostate cancer model. |
| 3488 | Computer #85 |
Intravoxel Incoherent Motion Diffusion-weighted Magnetic Resonance Imaging for Monitoring the Early Response to ZD6474 from Nasopharyngeal Carcinoma in Nude Mouse |
1GE Healthcare China, Shanghai, China, Shanghai, China, People's Republic of, 2Department of Radiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China, People's Republic of |
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This study was to investigate the feasibility of IVIM DWI to evaluate the early therapeutic effects of ZD6474 upon human NPC xenografts in nude mouse. NPC mice underwent IVIM DWI at baseline and after 1, 3, and 7 days of treatment. In the treated group, the f and D* decreased significantly on day 1 while the ADC and D were significantly higher from day 3 compared with the control group, demonstrating that IVIM DWI is sensitive to detect the ZD6474-induced changes in human NPC nude mouse, and the D* and f parameters could predict early response to anti-angiogenic treatment. |
| 3489 | Computer #86 |
Comparison of IVIM and BOLD MR imaging in Functional Evaluation of Diabetic nephropathy |
1Tianjin First Center Hospital, Tianjin, China, People's Republic of, 2Philips healthcare, Beijing, China, People's Republic of |
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To detect the changes of kidney diseases, magnetic resonance imaging(MRI) as a noninvasive approach has been proved to be more suitable for detecting and monitoring diabetic nephropathy(DN). Intravoxel incoherent motion (IVIM) and blood oxygenation level dependent (BOLD) MR imaging have been confirmed their high potential in detecting changes of renal function in patients with chronic renal diseases and transplanted kidneys. We compared the parameters of IVIM and BOLD in patients with DN and heathy controls. The results demonstrated the capacity of IVIM and BOLD for reflecting renal perfusion, diffusion and oxygenation changes in patients with DN. |
| 3490 | Computer #87 |
Diffusion Kurtosis Metrics as Biomarker of Fibre Maturity |
1Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich GmbH, Juelich, Germany, 2Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany, 3Experimental Physics III, TU Dortmund University, Dortmund, Germany, 4Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany, 5JARA - BRAIN - Translational Medicine, Aachen, Germany, 6Institute of Neuroscience and Medicine – 3, Forschungszentrum Jülich GmbH, Juelich, Germany, 7Translational Brain Research in Psychiatry and Neurology, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany, 8Child Neuropsychology Section, Department of Child and Adolescent Psychiatry and Psychotherapy, RWTH Aachen University, Aachen, Germany |
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Diffusion tensor imaging has enabled the examination of white matter connectivity and microstructural changes across the lifespan. However, the detection of subtle microstructural changes during typical brain maturation still remains challenging. Recently, diffusion kurtosis imaging has attracted much attention as an efficient method for characterising non-Gaussian water diffusion in brain tissue. Here, we tested whether diffusion kurtosis imaging can extend our knowledge of changes in brain tissue microstructure related to normal brain development. We showed that diffusion kurtosis imaging provides useful biomarkers sensitive to the level of maturity in association, projection and commissural fibres. |
| 3491 | Computer #88 |
Using intravoxel incoherent motion MR imaging to measure renal diffusion and perfusion in contrast-induced acute kidney injury |
1Department of Radiology, Guangdong Academy of Medical Sciences/Guangdong General Hospital, Guangzhou, China, People's Republic of, 2Russell H. Morgan Department of Radiology and Radiological Sciences, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore 21287, USA, Baltimore, AL, United States |
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Contrast-induced acute kidney injury (CI-AKI) is a common iatrogenic event caused by the injection of iodinated contrast agent, and remains the third major source of in-hospital acquired acute renal failure.The objective of our study is to examine the feasibility of using Intravoxel Incoherent Motion (IVIM) MRI to simultaneously measure the pathological changes in kidney diffusion and perfusion in the course of CI-AKI. Our results showed that the kidney perfusion and diffusion as measured by IVIM are well-correlated with those measured using conventional methods, indicating IVIM MRI can be used as an effective tool for the diagnosis and staging of CI-AKI. |
| 3492 | Computer #89 |
Assessment of brain structural network alterations in major depressive disorder using generalized q-sampling imaging and connectome analysis |
1Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, 2Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan, 3Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan, 4Department of Psychiatry, Chang Gung Memorial Hospital, Chiayi, Taiwan, 5Department of Psychology, Chung Shan Medical University, Taichung, Taiwan |
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Major depressive disorder (MDD) is the most common mood disorder in the world and the most important precursor of suicide. Despite decades of research, the pathophysiology of MDD remains not well understood. Recently, several MRI studies have focused on structural and functional connectivity evaluation and suggested that alterations of some specific regions of the brain, in both gray and white matter structures and some specific cortical–subcortical neuronal circuits, may play important roles of MDD. Generalized q-sampling imaging (GQI) is a more accurate and sophisticated diffusion MR approach compared to diffusion tensor imaging (DTI), which can extract additional information about the altered diffusion environments to resolve the complicated neural structure changes of neural disease. In this study, we used GQI and graph theoretical analysis to evaluate brain structure and connectivity change of MDD compared to healthy controls and correlation with symptom severity. Our results indicated GQI indices can help to detect structural and connective abnormalities of MDD patients and these alterations are correlated with depressive severity. |
| 3493 | Computer #90 |
Evaluation of Acute Cerebral Infarction Using a Fast Kurtosis Diffusion imaging Protocol |
1Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China, People's Republic of, 2MR Collaborations NE Asia, Siemens Healthcare, Beijing, China, People's Republic of, 3Department of Radiology, University of Illinois at Chicago, Chicago, IL, United States, 4Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States |
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Conventional DKI is limited in use for detecting acute stroke because of its relatively long scan time and current need of offline processing. Here we used a 13 directions protocol combined with simultaneous multi-slice technique with inline reconstruction to test the diffusion pattern at different time points. The results shows the lesion size observed within 24hr on MK matched with the lesion size on T2-FLAIR after one month, which was better than lesion size observed within 24hr on DWI. Early application of the fast DKI to detect the anomalous range of MK was beneficial to predict the range of the eventual infarction for clinical treatment. |
| 3494 | Computer #91 |
High resolution tract density tract-based spatial statistics and automating fiber-tract quantification analysis in patients suffering from major depressive disorder |
1Institute for Biomedical Engineering, ETH and University of Zurich, Zurich, Switzerland, 2Department of Psychiatry, Psychotherapy and Psychosomatics Psychiatric Hospital, University of Zurich, Zurich, Switzerland, 3Division Neuropsychology, Departement of Psychology, University of Zurich, Zurich, Switzerland, 4Neuroscience Center, University and ETH Zurich, Zurich, Switzerland, 5Department of Psychology, University of Bern, Bern, Switzerland |
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In the last few years, tract base spatial statistics (TBSS) and automating fiber-tract quantification (AFQ) have become prominent tools for analyzing diffusion data in group studies. In this study, we introduce optimized high-resolution tract density (optTD) images and analyze these maps using TBSS and AFQ in patients with major depressive disorders. We show a higher sensitivity in the newly introduced optTD compared to traditional FA analyses. Significant group differences were found using both methods indicating robust findings. High resolution optTD maps derived from optimized tractograms provide a promising tool for investigating white-matter abnormalities in mental disorders. |
| 3495 | Computer #92 |
Diffusional Kurtosis Imaging Study Of Parkinson Disease |
1Department of Medical Imaging, the 2nd Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China, Shantou, China, People's Republic of |
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Eighteen Parkinson Disease’s (PD) patients and four healthy controls(HC) underwent the diffusional kurtosis imaging (DKI) and then we tested the PD’s patients with Hoehn-Yahr scale and Unified Parkinson Disease Rating Scale(UPDRS). As a result, we found a significant decrease of Mean kurtosis (MK) values in the left substantia nigra between PD’s patients and healthy controls. Moreover, the kurtosis fractional anisotropy (KFA) values in right red nucleus of the PD’s patients were positively associated with the UPDRS scores in our study. |
| 3496 | Computer #93 |
Characterization of Clear Cell Renal Cell Carcinoma with Diffusion Kurtosis Imaging: Correlation between Diffusion Kurtosis Parameters and Tumor Cellularity |
1renji hospital, shangha, China, People's Republic of, 2MR, Philips Healthcare, Shanghai, China, People's Republic of |
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A wide spectrum of the use of DKI to characterize non-Gaussian diffusion pattern in microstructural tumor tissue has been developed involving a variety of tumors. However, the feasibility of DKI in kidney has been assessed in healthy volunteers only. The study was assigned to assess the quantitative DKI in grading of clear cell renal carcinoma (ccRCC) and to compare the correlation between DKI parameters and tumor cellularity and found that DKI could not only quantitatively characterize ccRCC with different grades but also provide valuable information on the diffusion properties related to tumor microenvironment changes or tissue complexity in tumor. |
| 3497 | Computer #94 |
Diffusional kurtosis imaging study in idiopathic normal pressure hydrocephalus patients, before and after shunt placement surgery analysis |
1Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, Bangkok, Thailand, 2Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, Beijing, China, People's Republic of, 3Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, Bangkok, Thailand, 4Department of Preventive and Social Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, Bangkok, Thailand, 5Departments of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, Bangkok, Thailand, 6Department of Psychiatry, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, Bangkok, Thailand |
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Idiopathic normal pressure hydrocephalus(iNPH) is important reversible cause of dementia and gait abnormality in elderly patients. Diffusional kurtosis imaging(DKI) moreover explains the complexity of white matter abnormality with inclusion of non-Gaussian effects. We aim to identify difference of complexity of white matter alteration in iNPH patients before and after shunt placement surgery by using high resolution DKI. We report significant increase of mean diffusional kurtosis(Kmean), mean diffusivity(MD) and decrease of radial diffusional kurtosis(Krad) , fractional ansiotropy(FA) after shunt placement surgery. High resolution DKI can be used for monitoring and detection complexity of white matter alteration in iNPH patients. |
| 3498 | Computer #95 |
The Investigation of Cerebral Microstructure Changes of Pediatric Patients With Type Ⅰ Gaucher Disease Using Diffusion Kurtosis Imaging |
1Imaging center, Beijing Children’s Hospital, Capital Medical University, Beijing, China, People's Republic of, 2Imaging Systems Clinical Science, Philips Healthcare, Beijing, China, People's Republic of |
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Increasing clinical studies suggested that there are some type Ⅰ Gaucher disease (GDⅠ) patients suffering neurological symptom, which was originally defined as non-neuropathlogical involved. This study recruited 38 patients and 32 normal children to investigate morphological changes of brain in GDⅠ patients by using Diffusion Kurtosis Imaging. Our results showed significant decreased MD in bilateral olfactory gyrus, increased MD in right calcarine and substantia nigra and significant increased MK in right olfactory gyrus. Our study suggests a necessity of adjusting the opinion regarding the CNS-involvement of GDⅠ, and DKI analysis is a potential imaging marker in clinical studies of GDⅠ. |
| 3499 | Computer #96 |
Differentiating Minimal Fat Angiomyolipoma from clear cell Renal Cell Carcinoma: comparison of monoexponential, biexponential, and stretched exponential Diffusion-weighted imaging |
1Departments of Radiology, Tongji Hospital, Tongji Medical College, WU HAN, China, People's Republic of, 2GE Healthcare,MR Research China,WU HAN, WU HAN, China, People's Republic of |
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Since DWI with different models may demonstrate different aspects of tissue properties, it should be valuable to compare and explore their roles in renal tumors. To our knowledge, however, no comparison of these different diffusion imaging approaches for the differential diagnosis in renal tumors has been investigated so far. The purpose of this study was to quantitatively compare and evaluate the potential clinical value of various diffusion parameters obtained from monoexponential, biexponential, and stretched exponential DWI models for differentiation of MFAML from ccRCC. |
| Exhibition Hall | Tuesday, May 10, 2016: 16:00 - 17:00 |
| 3500 | Computer #1 |
7 Tesla dual element 31P TxRx/1H Rx endorectal coil combined with an 8-channel 1H-TxRx body coil |
1Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, Netherlands, 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany |
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Multiparametric MRI (mpMRI) is a valuable tool to assess aggressiveness and stage of localized prostate cancer. When combined with metabolic information from 1H and 31P spectra valuable information on the metabolism of the disease can be derived. Here we demonstrate a dual element endorectal coil with 1H Rx and 31P TxRx capabilities combined with an external 8-channel transmit-receive body array. One patient (Gleason score 4+4) was measured. High quality proton spectra show elevated total choline in tumor tissue, which corresponded with increased glycerophosphocholine, glycerophosphoethanolamine and phosphocholine in the 31P spectra of the tumor. |
| 3501 | Computer #2 |
Prostate MRI at 7.0 Tesla using an actively-tuned endorectal coil |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States |
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Using endorectal coils (ERC) in combination with external surface arrays (ESA) can improve the SNR inside the prostate at 7.0T. When used in transmit, ERC can provide higher B1+ levels at the expense of field uniformity. Here, we develop a novel actively-tuned ERC that can be used both in “transmit” and “receive-only” modes utilizing the high B1+ of the ERC and field uniformity of the ESA inside the prostate. Transmit capabilities of this approach are investigated using simulations in a human model. Prostate MRI is acquired using the combined ESA+ERC approach to demonstrate the feasibility for translational studies at 7.0T. |
| 3502 | Computer #3 |
The Trellis Coil: A Morphing, Size Adaptable Array Coil |
1The Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, 2The Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, 3University of Pennsylvania, Philadelphia, PA, United States |
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The sensitivity of surface coil arrays can be maximized by conforming them closely to the human body, maximizing coil loading and minimizing the contribution of coil noise. There is, however, great diversity in body shape and size. Rigid coils must adopt a compromise, allowing for the largest cases while not giving up too much sensitivity when imaging smaller examples. Flexible arrays can be wrapped tightly around the body, but if the overall array dimensions are fixed there will always be gaps or undesired overlaps depending on body habitus. We present here a geometrical approach based on a trellis-like lattice of interlinked slats which allows a surface coil array to be re-shaped while maintaining coil tuning, coil loading and decoupling of neighboring coils. |
| 3503 | Computer #4 |
Liquid metal based deformable transmitter for MR imaging: A feasibility study |
1Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States, 2UNC/NCSU Joint Department of Biomedical Engineering, University of North Carolina of Chapel Hill, Chapel Hill, NC, United States, 3Biomedical Research Imaging Center, University of North Carolina of Chapel Hill, Chapel Hill, NC, United States, 4Department of Chemical & Biomolecular Engineering, NC State University, Raleigh, NC, United States |
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Recent advances of liquid metal technology have made it possible to build deformable RF transmitters. Such coils have many attractive features for MR, such as easy reconfiguration, flexibility, and self-healing capabilities. However, given that the conductivity of liquid metal is more than an order of magnitude lower than the copper, it is unclear whether it is suitable to be used as a RF transmitter in MR applications. In this work, such feasibility was demonstrated by comparing the performance of two electric dipole antennas with similar size, one made of liquid metal and the other one made of copper, on a 7T scanner. |
| 3504 | Computer #5 |
RF coil design for multi-nuclear lung MRI of 19F fluorinated gases and 1H using MEMS |
1Unit of Academic Radiology, University of Sheffield, Sheffield, United Kingdom, 2GE Healthcare, Aurora, OH, United States |
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Mutli-nuclear lung MRI using inhaled inert fluorinated 19F gas and 1H provide complementary structural-functional information. The close MR resonance frequencies of the two nuclei preclude the use of dual-tuned coils using trap circuits. Thus, we introduce the use of Micro-electromechanical systems (MEMS) in a quadrature transmit-receive RF coil to switch between two resonance frequencies of 19F and 1H at 1.5T. Characterization of the additional loss and co-registered imaging of 19F and 1H with a custom-built body sized phantom is demonstrated. |
| 3505 | Computer #6 |
Performance of 7 Tesla Normal Metal and Superconducting Cryo-coils for MRI of Rat Brain |
1Electrical and Computer Engineering, University of Houston, Houston, TX, United States, 2Texas Center for Superconductivity, University of Houston, Houston, TX, United States, 3Radiology, The University of Texas Health Science Center, Houston, TX, United States, 4The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center, Houston, TX, United States, 5Institute of Physics of Polish Academy of Science, Warsaw, Poland |
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We report on the performance of receive only 300-MHz planar cryogenic (both copper and superconducting) coils for MRI of rat brain at 7 T. The double-sided coils were fabricated by patterning Cu and YBCO on laminate and 0.33 mm thick sapphire substrate, respectively. Practical limits of the performance of the cryocoils (20 mm Cu and 17 mm superconducting) were tested using 3D-RARE, 2D-RARE, and RGB-FA maps recorded with EPI_DTI protocols. Both in-vivo and ex-vivo images were acquired. Twofold SNR gain was achieved at 65K. Cryo-system stability tests with over 11 hours of DTI ex-vivo scanning are presented. |
| 3506 | Computer #7 |
8CH 19F/1H Transceiver Array for Lung Imaging at 7T (pTX) |
1MRI.Tools GmbH, Berlin, Germany, 2Division of Medical Physics in Radiology, Cancer Research Center (DKFZ), Heidelberg, Germany, 3Diagnostic and Interventional Radiology, University Medical Center Ulm, Ulm, Germany, 4Berlin Ultrahigh FieldFacility (B.U.F.F.), Max Delbrück Center for Molecular Medicine, Berlin, Germany |
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Lung MR-Imaging is challenging due to low proton density in the lung. Ventilation can only be visualized directly using exogenous contras agents such as hyperpolarized noble gases or 19F-containing gasses as a “contrast agents”. This work proposes a multi-channel transmit and receive (TX/RX) radiofrequency (RF) coil that supports eight TX/RX channels (4 loop- and 4 dipole-elements) for 19F and 1H lung imaging at 7.0T using a pTX-array. |
| 3507 | Computer #8 |
Comparison between commercial RF head coils and a new hybrid transmit-array coil based on 12 transmit elements and 22 receive elements for an 8-channel transmission system at 7 T |
1CEA, DSV, I2BM, NeuroSpin, UNIRS, Gif-sur-Yvette, France, 2CEA, DSM, IRFU, SACM, LISAH, Gif-sur-Yvette, France |
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This work compares the performance of two commercial RF coils with a new transmit-array hybrid coil developed at NeuroSpin for the human head at 7T. This z-segmented coil uses 11 transceiver dipoles connected to 7 power channels via an SVD-box, one transceiver patch to cover the top of the head, and 10 receive-only 3D loops in-between the dipoles. Its performance outbeats that of the commercial coils both in terms of signal-to-noise ratio and dynamic RF shimming efficiency. |
| 3508 | Computer #9 |
A size-adaptable electric dipole array for 7T body imaging |
1Department of Radiology, The Bernard and Irene Schwartz Center for Biomedical Imaging, New York, NY, United States |
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A major challenge in 7T coil array design for body imaging is to achieve optimum distribution in different body sizes with only one coil array. In this work, we propose a flexible 8 channel dipole array with trellis-like substrate which can expand and contract to fit various body sizes and hold electric dipole antenna elements in the optimum distribution around the body for all subjects. The performance of the trellis array was compared with a flexible yet fixed-element-spaced folded dipole body array [1] in terms of flip angle maps and SNR on two different sizes of body phantoms. Both phantom and invivo images show that the trellis array does not have common nulls between the circular polarized (CP) and gradient modes. |
| 3509 | Computer #10 |
13C MRS in human calf muscles at 7T using a double tuned 4 channel 13C-4 channel 1H transceiver phased array. |
1Laboratory of Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2Department of Radiology, Universities of Lausanne and Geneva, Lausanne, Geneva, Switzerland |
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The inherent low sensitivity of 13C MRS makes direct 13C detection challenging. Moreover, the 13C-1H heteronuclear J coupling requires double tuned 13C-1H coils to perform proton decoupling during 13C signal acquisition. High sensitivity can be achieved over a large field-of-view using array coils. We aimed to design and build a 4 channel 13C-4 channel 1H transceiver phased-array coil for 13C-MRS studies in humans at ultra-high field. Electromagnetic performance of the coil was evaluated by FDTD simulations in calf muscles at both frequencies. Finally, 1H-decoupled 13C resonance of Glycogen C1 was successfully detected in volunteer calf muscles at 7T. |
| 3510 | Computer #11 |
Use of the ultimate signal-to-noise ratio to assess the impact of coil coverage for brain imaging |
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Cadence Design Systems, Feldkirchen, Germany, 3Skolkovo Institute of Science and Technology, Moscow, Russian Federation, 4Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 5Harvard-MIT Division of Health Sciences Technology, Cambridge, MA, United States, 6Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States |
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We assess the impact of coil coverage for brain imaging at 3 T and 7 T using the ultimate SNR (uSNR). We simulate three coil configurations that cover (i) the whole head (ultimate), (ii) the whole head but the neck (realistic ultimate) and (iii) the head except the neck and face (helmet geometry). We compute the maximum SNR (unaccelerated and accelerated) achievable by any coils with these head coverage using random excitations of a dense dipole cloud placed around the head. Not covering the face (eye/nose/mouth) and neck has little impact on unaccelerated and accelerated SNR compared to the ultimate. |
| 3511 | Computer #12 |
A multisegment detunable HEM-mode dielectric resonator for increased patient comfort at 7 T |
1Radiology, Leiden University Medical Center, Leiden, Netherlands |
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At ultrahigh field (≥7T) cavity- and waveguide-based RF coils become possible to construct, and have the advantage that simple designs can be used. One such design uses materials with a high dielectric constant. So far only completely circular structures have been produced; to improve the usability of such a dielectric resonator, it is important to be able to design a splittable and easily detunable resonator. In this work, we tested designs that allow splitting of the cylinder to sections, while maintaining the circularly polarized RF field. In-vivo measurements of the knee at 7 Tesla showed the feasibility of this approach. |
| 3512 | Computer #13 |
Segmented Dipole: A Remotely Reconfigurable Near-Field Dipole Antenna Transmitter for Optimized 7 T Spine Imaging |
1Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States |
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7T spine array based on electric dipole antenna starts to gain attention recently. Nevertheless, the transmit efficiency of the dipole has a natural decay from the feeding point, which does not necessarily corresponding to the target imaging area. In addition, a variety of patient size requires the dipole to be reconfigured for optimum performance. In this work, we propose a concept of “segmented dipole” that can be remotely reconfigured for transmit field-of-view shifting, tuning, and impedance matching characteristics without the need of a parallel-transmit system. A prototype transmitter was built and the reconfiguration capability was demonstrated at a 7T scanner. |
| 3513 | Computer #14 |
Dedicated surface coils for MR studies in the temporal and the frontal lobes of the human brain at 7T |
1CIBM-LIFMET, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2CIBM-AIT, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3LIFMET, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 4Department of Radiology, University of Geneva, Geneva, Switzerland, 5Department of Radiology, University of Lausanne, Lausanne, Switzerland |
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The purpose of the study was to build dedicated surface coils for the temporal and the frontal lobes of the human brain at 7T. Their transmit field efficiency and single-voxel spectroscopy performances were compared with a birdcage coil with a dielectric pad. An increased B1+-field for the brain regions was measured with the surface coils compared to the birdcage with the pad, which allows single-voxel SPECIAL spectroscopy and anatomical image acquisitions in the peripheral temporal and frontal lobes. |
| 3514 | Computer #15 |
A combined microcoil and microdialysis approach to measure metabolic response in real-time. |
1University of Southampton, Southampton, United Kingdom, 2CRMSB, Université Bordeaux, Bordeaux, France, 3Université Bordeaux, Bordeaux, France, 4CEA Saclay, Gif-sur-Yvette, France |
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We present two highly sensitive microcoil probes (1H and 13C) that are connected to microdialysis probes inside a MRI scanner. Under continuous flow conditions the metabolic response can be monitored in real-time in vitro and in vivo. |
| 3515 | Computer #16 |
High Spatial Resolution Functional Imaging of Human Temporal Lobe Cortical Layers at 3T |
1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, 2Institute of Applied Physics, National Chengchi University, Taipei, Taiwan, 3Institute of Neuroscience, National Yang Ming University, Taipei, Taiwan |
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By using a dedicated 24-channel coil array and tailored sequence, we achieved human temporal lobe functional imaging with 1.5 mm isotropic resolution. Our coil array had two-fold SNR and tSNR improvement in the temporal lobe compared to a 32-channel whole-head coil array. Functional MRI showed more robust BOLD signals elicited by music stimuli in the primary auditory cortex. Tonotopic mapping revealed the clearest frequency progressions in the middle layer of auditory cortex gray matter, which was consistent with the result acquired by electrophysiological recordings on rodents. |
| 3516 | Computer #17 |
A Slot Antenna Concept for High Fidelity Body Imaging at Ultra High Field |
1Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States, 2Center for Biomedical Imaging, New York University School of Medicine, New York, NY, United States, 3NYU Wireless, NYU-Poly, New York, NY, United States, 4RF Test Labs, New York, NY, United States |
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In recent years dipoles and other radiative antenna structures have become popular for ultra high field MR imaging. In this work, we introduce the radiative slot antenna, which generates a horizontally polarized E field showing promise as a simple coil structure for high fidelity axial imaging. |
| 3517 | Computer #18 |
A Novel 8-channel transceive open knee coil for dynamic musculoskeletal imaging at 7 Tesla |
1ITEE, The University of Queensland, Brisbane, Australia |
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Magnetic resonance imaging (MRI) is a very important non-invasive modality for the diagnosis of knee anatomy and pathology. The use of 7 Tesla systems for knee imaging can provide higher signal-to-noise ratios (SNR) than lower field systems. In this work, a novel 8-channel transceive open knee coil for dynamic musculoskeletal (MSK) MR imaging of the knee is simulated and constructed. The open design concept will facilitate the diagnostic and functional assessment of knee injuries and pathology, and allow for imaging of a moving knee. |
| 3518 | Computer #19 |
A 4-element dual-tuned 1H/31P coil array for MR imaging and spectroscopy of the human heart at 3 Tesla |
1Department of Radiology, Academic Medical Center, Amsterdam, Netherlands, 2MR Coils B.V., Drunen, Netherlands, 3Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, Netherlands, 4Philips Healthcare Benelux, Eindhoven, Netherlands, 5Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 6Neuroimaging Center, University Medical Center Groningen, Groningen, Netherlands |
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Maximizing the signal-to-noise ratio (SNR) in in vivo cardiac phosphorus-31 magnetic resonance spectroscopy (31P-MRS) remains a major challenge in investigations of human myocardial energy metabolism. Here, we demonstrate that with a dual-tuned 1H/31P coil array with 4 elements, it is feasible to achieve a higher SNR and a more homogeneous receive sensitivity distribution over the region of interest for cardiac 31P-MRS at 3 Tesla than with a standard linear single-turn 31P surface coil. Furthermore, the 4 channels available for 1H signal reception allow for cardiac cine 1H-MRI with parallel imaging. |
| 3519 | Computer #20 |
Assessment of coil arrays with small loop diameter at 7T for micron-scale resolution fMRI of human neocortex. |
1Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States, 2Advanced MRI Technologies, Sebastopol, CA, United States, 3Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 4Virtumed, LLC, Minneapolis, MN, United States |
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The use of array coils with smaller loop sizes allows increased signal to noise ratio close to the coils with decreased coverage of the brain. By focusing on cortical imaging (MR Corticography, MRCoG), this increased SNR can be leveraged to allow ultra-high resolution neuroimaging and fMRI. We assess array coils with varying loop sizes (50mm-20mm) in phantom and with 8-channel arrays (70mm, 40mm, 30mm) in brain at ultra-high resolution (≤ 500 micron isotropic voxels), and show increases in SNR and BOLD contrast in the human cortex as loop size decreases. |
| 3520 | Computer #21 |
A larger subject Field-of-View and denser coil arrays at UHF: What do we gain? |
1Dept. of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands, 2Dept. of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States |
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Functional magnetic resonance imaging (fMRI) of the human brain has now become the preferred method for mapping functional pathways in the human visual cortex, among other brain regions. At ultra-high fields of 7 Tesla and above, the increased Contrast-to-Noise ratio for blood oxygenation level dependent (BOLD) techniques further facilitates this acquisition methodology. We designed and constructed a frontally open RF coil with a phased array transmit and a dense receiver array layout for human visual cortical imaging at 7 Tesla, specifically for visual fMRI experiments at sub-millimeter resolutions. We compared the coil's performance to that of a standard 32-channel whole-brain volume coil to inquire into its efficacy as a suitable substitute for the whole-brain coil for high resolution fMRI. |
| 3521 | Computer #22 |
An investigation of coupling and loading effects for adaptive coil design |
1Siemens Healthcare GmbH, Erlangen, Germany, 2Siemens Medical Solutions USA, Inc., Malvern, PA, United States, 3Department of Radiology, New York University School of Medicine, Center for Advanced Imaging Innovation and Research (CAI2R) and Center for Biomedical Imaging, New York, NY, United States |
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This abstract examines the feasibility of an adaptive coil design to overcome the disadvantage of poorly loaded and non-fitting local coils. The coil adjusts to the circumference of e.g. a knee by changing the overlap between coil elements. Through bench measurements and simulation we investigated the tradeoff between maintaining optimal coil loading and signal-to-noise ratio (SNR) losses due to coupling. Broadband matching was considered to reduce SNR degradation. Although results show that an adaptive coil can minimize coil losses, the non-ideal overlap of this design leads to a larger SNR degradation than the coil losses of a non-perfect fitting coil. |
| 3522 | Computer #23 |
Decoupling between coils in a flexible phased-array using stacked circumferential shielding |
1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan |
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We propose a flexible coil array design consisting of circumferential shielding stacked on circular coils to achieve robust decoupling between coil when the array is either bended or on a flat plane. Two types of circumferential shielding were tested through numerical simulation. The results demonstrated that both types can have good decoupling on a curved surface with S21 < -17.1 dB. The maximum |B1| for the array coil with Type-II (two-parallel-ring) shielding was 63% larger than that with Type-I (single-strip) shielding. Future work will empirically construct these coils to compensate simulation inaccuracies and validate their performance In Vivo. |
| 3523 | Computer #24 |
Sensitive detection of hemodynamic responses to TMS pulse at human sensorimotor cortex |
1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, 2Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 3Institute of Applied Physics, National Chengchi University, Taipei, Taiwan, 4Institute of Neuroscience, National Yang Ming University, Taipei, Taiwan |
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We tested how TMS pulses and the separation between TMS pulse and RF excitation affect MRI SNR and tSNR using our tailored 8-channel TMS-compatible MRI coil array. Result from an in vivo experiment using this integrated system to record the BOLD signal elicited by TMS pulses at human primary motor cortex is also reported. |
| Exhibition Hall | Tuesday, May 10, 2016: 16:00 - 17:00 |
| 3524 | Computer #49 |
Dipole Array Design Considerations for Head MRI at 10.5T |
1U. of Minnesota, Minneapolis, MN, United States |
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An 8-channel dipole array is a promising structure for human head imaging at 10.5T. In order to optimize the structure for efficiency and homogeneity over the brain, many variations of the dipole were numerically simulated and compared. The variations include varying dipole lengths, warping the dipole, adding shielding, adding dielectric padding or dielectric mirrors and including decoupling capacitors. Compared to a design in use, numerical results predict the RF homogeneity can be greatly improved with a 210 mm dipole array while simultaneously lowering the peak local 1 gram and 10 gram SAR. |
| 3525 | Computer #50 |
Analytical Modeling of the Coupling within a Human Head Surface Loop Transmit Phased Array at Ultra-High Fields |
1High-field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 2Institute for Biomedical Engineering, UZH and ETH Zurich, Zurich, Switzerland |
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Decoupling of multi-channel ultra-high field (>7T) transmit and transceiver arrays is a major issue. Analytical modeling of the coupling can facilitate the array optimization. We developed an analytical model describing the impedance matrix for two rectangular loops placed on a cylindrical surface and mimicking the human head array geometry. The developed model was comprehensively validated and allows for the optimization of the geometry and positioning of the loops. The latter enabled simultaneous cancellation of resistive and inductive coupling without additional decoupling circuits. The resulting overlapped array element arrangement improves both transmit and receive performance in comparison to conventional gapped arrays. |
| 3526 | Computer #51 |
Optimization of the antenna-subject spacing for transceive surface arrays of dipole antennas at 7T |
1Department of Nanophotonics and Metamaterials, ITMO University, Saint-Petersburg, Russian Federation, 2Imaging Division, UMC Utrecht, Utrecht, Netherlands |
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Dipole antennas are being used increasingly for body imaging at 7T. For dipole antennas, SAR levels can be reduced by increasing the antenna-subject spacing. However, this will increase inter-element coupling. In this study we investigate the relationship between antenna-subject spacing, inter-element coupling and maximum local SAR levels for fractionated dipole antennas. We demonstrate that the originally presented antenna-subject spacing (2 cm) can be increased without significant scattering losses. We have realized an 8-element array of fractionated dipole antennas with 4 cm antenna-subject spacing and demonstrate uncompromised imaging performance with 45% lower local SAR levels in comparison to the original design. |
| 3527 | Computer #52 |
Evaluation of through-time radial GRAPPA for real-time cardiac MR imaging at 7 Tesla |
1Erwin L. Hahn Institute for Magentic Resonance Imaging, University Duisburg-Essen, Essen, Germany, 2High Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany, 3Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany, 4Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States |
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Accelerated radial data acquisition of the myocardium in combination with through-time radial GRAPPA offers the opportunity for real-time visualization of cardiac motility without the need for additional ECG or pulse wave synchronization. This is particularly useful in an ultrahigh-field MR environment where conventional gating methods in combination with cardiac dysrhythmia tend to fail. In this work, the performance of through-time radial GRAPPA against an established Cartesian k-space encoding protocol featuring pulse-triggered cine-FLASH has been evaluated and its role as an alternative for real-time cardiac 7-Tesla MR imaging is shown. |
| 3528 | Computer #53 |
Enabling axial diffusion tensor imaging of the human cervical spinal cord at 7T |
1Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR 7339, CNRS, Aix-Marseille Université, Marseille, France, 2Centre d'Exploration Métabolique par Résonance Magnétique (CEMEREM), Hôpital de la Timone, Pôle d’imagerie médicale, AP-HM, Marseille, France |
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MRI at 7T has recently demonstrated its ability to provide high-quality anatomical images of the spinal cord (SC), yet no diffusion tensor imaging (DTI) study was reported so far. Single-shot echo-planar imaging (ss-EPI) is the method of choice for DTI but the sequence is seriously limited by strong susceptibility artifacts. This work demonstrates that a thoughtful implementation of ss-EPI at 7T combined with distortion correction post-processing from two acquisitions with opposed phase-encoding directions can generate high-resolution axial DTI images of the cervical SC with added value compared to lower field standard protocols making SC DTI ready for UHF clinical investigations. |
| 3529 | Computer #54 |
The traveling heads: Qualitative and quantitative evaluation of multicenter brain imaging at 7 Tesla |
1Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Hospital Essen, University of Duisburg-Essen, Essen, Germany, 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany, 3German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany, 4Otto-von-Guericke-University, Magdeburg, Germany, 5Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck-Center for MolecularMedicine, Berlin-Buch, Germany, 6Medical Physics in Radiology, German Cancer Research Center (dkfz), Heidelberg, Germany, 7High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medial University of Vienna, Vienna, Austria, 8ScanNexus, Maastricht, Netherlands, 9Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 10Experimental and Clinical Research Center, a jointcooperation between the Charité Medical Faculty and the Max Delbrück Center for MolecularMedicine, Berlin, Germany, 11High Field and Hybrid MR Imaging, University Hospital Essen, University Duisburg-Essen, Essen, Germany, 12Donders Centre for Cognitive Neuroimaging, Nijmegen, Netherlands, 13Leibniz Institute for Neurobiology, Magdeburg, Germany |
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The “traveling heads” is an experiment started in 2014 to assess the comparability and reproducibility of multicenter human brain imaging at 7T. This is of particular interest as 7T MRI is currently being discussed to become a clinical system in the very near future. The number of installations continues to increase, with currently approximately 60 research sites in operation worldwide. As an advantage, this new technology provides higher SNR, yet the artifact-to-noise ratio is also increased. This can influence the image quality severely and may be different at individual UHF sites, where system hardware differences could diminish reproducibility. |
| 3530 | Computer #55 |
Very high order B0 Shimming of the human brain at 9.4 T considering Real B0 Shim Fields |
1Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 2IMPRS for Cognitive and Systems Neuroscience, Eberhard Karls University of Tuebingen, Tuebingen, Germany, 3Institute for Biomedical Engineering, UZH and ETH Zurich, Zurich, Switzerland |
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A highly homogeneous B0 field is essential if we are to exploit the advantages of higher field strengths for MR applications. In this work, we model the real field of each shim channel of a 4th order shim system for a 9.4T MR system for in vivo B0 shimming applications. Each shim channel is modelled at a range of frequencies to account for the possibility of amplitude nonlinearities. By modelling the fields generated by each shim channel, we were able to achieve better shim qualities than if perfect fields were assumed. |
| 3531 | Computer #56 |
B1+ homogenization at 7T using an innovative meta-atom |
1UNIRS, CEA Saclay - DSV - I2BM - Neurospin - UNIRS, Gif-sur-Yvette, France, 2CNRS, Aix-Marseille Université, Centrale Marseille, Institut Fresnel, UMR 7249, Marseille, France |
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B1+ heterogeneity at ultra-high field (UHF) can be tackled performing “passive shimming” with High-Dielectric Constant (HDC) pads. Nevertheless, HDC pads have shown structural, manufacturing and composition constraints. Here, we substitute HDC padding with a new meta-atom (MA) structure with a high equivalent dielectric constant, leaving behind the identified limitations. In this work, we compare this MA structure to a classic BaTiO3 pad used in UHF clinical routine. Results demonstrate this solution to strongly impact local B1+ distribution. Implementing multiple MA structures into the coil design might suggest a good potential for brain global B1+ inhomogeneity mitigation. |
| 3532 | Computer #57 |
Improving travelling wave efficiency at 7 T using dielectric material placed ”beyond” the region of interest |
1Radiology, Leiden University Medical Center, Leiden, Netherlands |
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The concept of traveling-wave MRI has been introduced for ultra-high fields, enabling large field-of-view excitation and physical separation between the antenna and the subject. Several studies have shown that introducing additional materials/structures into the magnet bore or surrounding the subject can improve the efficiency. In this work we explore the use of high permittivity material placed behind the region of interest and show that it can be beneficial for traveling wave efficiency. Separating the region of improved efficiency from that of the dielectric allow positioning of a receive array in the close proximity to the region of interest, physically separate from the dielectric material. |
| 3533 | Computer #58 |
Tuning Microstrip Coil Field Patterns Using Capacitor-Segmented Ground Planes |
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 2Radiology, Vanderbilt University, Nashville, TN, United States, 3Biomedical Engineering, Vanderbilt University, Nashville, TN, United States |
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At 7T and higher, the B1 fields of loop and microstrip coils become asymmetric. However, B1 fields of dipole antennas are still symmetric. The different behaviors of dipole and microstrip coils may be explained by the fact that they have similar magnetic-field vectors but different Poynting vectors. We propose to manipulate the Poynting vector and thus the symmetry of the B1 patterns of microstrip coils using capacitor-segmented ground (CSG) planes. This concept has been validated by numerical studies and practical MRI experiments. The CSG method provides additional flexibility for manipulating the shape of the B1 field, which may be advantageous for RF shimming and parallel transmission. |
| 3534 | Computer #59 |
Control of Excited Modes in Ultra High Magnetic Field MRI with Electrically Hard Surfaces |
1Department of Electrical, Computer, and Energy Engineering, University of Colorado at Boulder, Boulder, CO, United States, 2Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 3University of Minnesota, Center for Magnetic Resonance Research, Minneapolis, MN, United States |
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Traditional MRI reactive near-field probe design for B1 field uniformity assumes quasi-static fields. However, for B0>4T, the quasi-static approximation is no longer valid since the wavelength is smaller than the FOV and field wave modes appear, affecting image quality. This work presents the use of a copper strip waveguide structure combined with a traveling wave excitation at 7T, 10.5T human wide-bore and 16.4T small animal scanners, while observing the effect on a cylindrical distilled water phantom. A simple flexible copper strip wearable wrap is shown to improve SNR and field distribution in UHF-MRI. |
| 3535 | Computer #60 |
Theoretical and simulation verification of SNR enhancement in traveling wave MRI using free local resonators |
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 2Radiology, Vanderbilt University, Nashville, TN, United States, 3Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States |
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Traveling wave MR is a promising method for large field-of-view imaging at ultrahigh fields. However, a major issue currently faced in traveling wave MR is low transmit efficiency and limited SNR. It was found that the SNR in traveling wave MRI can be significantly improved by using a free local resonator. In this study, we validated this finding in simulation and extended the single loop to a multi-channel array. Based on the simulation results, the SNR on the phantom has a 16-fold gain (56.8 VS 3.6) at near area and 3-fold gain at far area (9.7 VS 3.5) with the help of the free loop. This improvement can be attributed to the secondary magnetic field caused by induced current of the free resonator. |
| 3536 | Computer #61 |
Zeroth-Order Resonator with Stepped Impedance for 7T Magnetic Resonance RF Coil |
1Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States, 2Department of Radiology, Center for Magnetic Resonance Research, Minneapolis, MN, United States |
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A planar structure based on a metamaterial transmission line Zeroth Order Resonance (ZOR) and Stepped Impedance Structure is designed as a MRI RF coil element. It generates high uniform magnetic field in the 7T Magnetic resonance imaging (MRI) system at 298 MHz, which improves the signal to noise ratio and the quality of the images. The full wave simulation and measurements show comparable results with the microstrip TEM RF coil element [1]. Additionally, it can generate uniform and high H-field intensity for any physical length of the coil as the resonance of the ZORs is independent of its length [2]. |
| 3537 | Computer #62 |
9.4T Animal Scanner for Translation Research with Binary Compatibility to Human Scanner and Clinical UI |
1INM-4, Forschungszentrum Jülich, Jülich, Germany, 22Faculty of Medicine, Department of Neurology, JARA, RWTH Aachen University, Aachen, Germany |
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In translational research going from animal model to in vivo human it is often desirable to change as few experimental parameters as possible. For this purpose a unique 9.4 T animal scanner has been assembled consisting of a dedicated small bore magnet and being operated with clinical software. Here we demonstrate an initial performance analysis of the system as well as some more advanced image acquisitions. |
| 3538 | Computer #63 |
Revised Transmit/Receive Loop Coil for 7T Usage |
1Philips, Cleveland, OH, United States |
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At 7T, T/R loop coils have challenges in transmit B1+-field efficiency and receive B1--field sensitivity in a spatial context, due to the increased tissue dielectric/wavelength effect. Here we propose a revised T/R loop coil schema which improves the B1-field non-uniformity at 7T. The proposed modification may make the T/R loop coil construct yet more useful at ultra-high fields. |
| 3539 | Computer #64 |
Feasibility of crossed-dipole antenna to excite a circularly-polarized field for human brain imaging at 7T, A design study |
1CIBM-AIT, EPFL, Lausanne, Switzerland, 2LIFMET, EPFL, Lausanne, Switzerland, 3Department of Radiology, University of Lausanne, Lausanne, Switzerland, 4Department of Radiology, University of Geneva, Geneva, Switzerland |
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The aim of this study was to investigate the crossed-dipole antenna by means of electromagnetic simulations and compare it with the surface quadrature head loop and volume head coils in terms of B1+ efficiency for 7T human brain imaging. The crossed-dipole antenna consists of two dipoles placed in a crossed form mounted upon/in an one-side conductor shielded dielectric. This antenna excites the circularly-polarized field and enhances the transmit efficiency in the occipital lobe in a larger FOV compared to the conventional coils. The comparison of the simulated B1+ maps of the coils showed that it is feasible to build it. |
| 3540 | Computer #65 |
Traveling Wave MRI at 7T Using Dielectric Wave-Guide |
1UT Southwestern Medical Center, Dallas, TX, United States, 2Children's Medical Center Dallas, Dallas, TX, United States, 3Children's Hospital of Philadelphia, Philadelphia, PA, United States |
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Traveling wave MRI uses a wave-guide for RF transmission. The metal bore of the scanner magnet serves as a wave-guide and extensions using conductor sheets may be added. Although dielectric materials are frequently introduced into the system, their intended function has been to modify the behavior of the wave-guide. In this work, we show that a dielectric material may be used as a wave-guide by itself, in a fashion similar to optic fibers guiding light transmission. We conducted MRI experiments at 7T using an insulator wave-guide constructed by filling a PVC tube with deionized water. |
| 3541 | Computer #66 |
Optimizing high permittivity materials for SAR minimization in transmit arrays: influence of the phase distribution of the excitation profile |
1The Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, 2The Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, 3The Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY, United States |
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Appropriate high-permittivity, low-conductivity materials placed between the RF coil and the sample can provide performance improvement in both transmission and reception. We employed a simulation framework based on dyadic Green’s functions for multi-layered spherical geometries to analyze how HPMs affect the tradeoff between excitation homogeneity and global Specific Absorption Rate (SAR) for RF shimming at 7T using an L-curves analysis. Three target excitation profiles were analyzed, with uniform amplitude and varied phase, to determine the influence that target phase distribution has on the optimal relative permittivity results. |
| 3542 | Computer #67 |
Evaluation of potential improvements from high permittivity pads for imaging upper extremities at 7 Tesla |
1Erwin L. Hahn Institute for MRI, University Duisburg-Essen, Essen, Germany, 2Department of Diagnostic and Interventional Radiology and Neuroradiology, University Duisburg-Essen, University Hospital, Essen, Germany, 3Radiology, Leiden University Medical Center, Leiden, Netherlands, 4Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 5High Field and Hybrid MR Imaging, University Duisburg-Essen, University Hospital, Essen, Germany |
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Two sets of dielectric pads with high permittivity (CaTiO3: 110 and BaTiO3: 286) were evaluated for potential improvements in imaging the shoulder joint and upper arm in combination with an 8–channel transmit/receive shoulder coil at 7 Tesla. In vivo images with structural PD TSE and DREAM flip angle maps were obtained and compared to measurements without pads present. Both a fixed RF shim as well as individual RF shimming were applied. For the investigated configurations, no substantial improvements in imaging upper extremities at 7 Tesla were found when applying high permittivity dielectric pads. |
| 3543 | Computer #68 |
Characterization of a breast gradient insert coil at 7 tesla with field cameras |
1Radiology, UMC Utrecht, Utrecht, Netherlands, 2Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark |
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In this work a gradient insert coil for breast MRI has been constructed. Its behaviour inside a 7T whole body MR system was characterized using magnetic field cameras. Furthermore, the possibility to correct eddy currents from the gradient insert coil using the built-in gradient set has been investigated. |
| 3544 | Computer #69 |
Extending the Sensitivity of a Head Coil toward Simultaneous Head and Neck Imaging Using High Permittivity Materials at 7 T |
1Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, 3Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY, United States |
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A standard head-coil may not be sufficient to examine regions inferior to the base of the skull. Previous work demonstrates that the field-of-view of a surface coil can be extended using high permittivity materials (HPM). In this work, we use calcium titanate bags to extend the sensitivity of a commercial head-coil, and demonstrate an increase in the signal-to-noise ratio in the neck muscles, brainstem and superior regions of the spinal cord and cervical vertebrae. Our results indicate that extending the sensitivity of any commercial coil may be possible using appropriately positioned HPMs. |
| 3545 | Computer #70 |
7T 8-channel pTx head coil with high B1+ efficiency optimized for MRS |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany |
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A 7T 8-channel transmit/receive head volume coil is introduced which is capable to produce transmit fields in the human brain of more than 50 µT necessary for single voxel MRS with acceptable chemical shift artifacts. Key to this good transmit field efficiency was careful design and material selection but also the choice of relatively short coil elements. From the simulation based design process appropriate input power limits were concluded which allow safe operation of the coil in compliance with IEC 60601-2-33. |
| 3546 | Computer #71 |
On the robustness and reproducibility of spatially selective excitation using parallel transmission at 7T – a multicenter study |
1University of Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany, 2German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany, 3Medical Physics in Radiology, German Cancer Research Center (dkfz), Heidelberg, Germany, 4Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany, 5High Field and Hybrid MR Imaging, University Hospital Essen, University of Duisburg-Essen, Essen, Germany, 6High Field and Hybrid MR Imaging, University Hospital Essen, University Duisburg-Essen, Essen, Germany |
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Parallel transmission (pTx) allows the excitation of arbitrarily shaped patterns or reduced field-of-view imaging and is of particular interest in ultra-high field MRI where it is used to diminish artifacts caused by B1 inhomogenities. However, calculation of arbitrarily shaped pulses is not included in standard pTx system procedures, is time consuming, and can only be done with knowledge of additionally acquired transmit B1 fields. To optimize this workflow, it might be advantageous to share pre-calculated pulses between different systems and/or coils. Image patterns were generated and optimized to assess image quality and to evaluate reproducibility and robustness of shared pulses. |
| 3547 | Computer #72 |
Simulated phase of driving voltage for travelling wave MRI with a parallel-plate waveguide at 7 T |
1Physics Department, Faculty of Sciences, UNAM, Mexico, DF, Mexico, 2Dep Electrical Engineering, UAM Iztapalapa, Mexico DF, Mexico |
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Travelling wave magnetic resonance imaging (twMRI) offers to overcome the inhomogeneities due to the standing wave patterns, and the use of coil arrays with multiple coil elements. The excitation of the spins have been commonly done with RF surface coils, dipole and patch antennas, etc. The resonant device should be able to generate an adequate magnetic field to transmit the signal to a distant object using a waveguide. In this paper, we numerically simulated the magnetic field of the principal mode (TM0) as a function of the driving voltage phase. |
| Exhibition Hall | Tuesday, May 10, 2016: 16:00 - 17:00 |
| 3548
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Computer #25 |
A multi-channel gradient driver system for matrix gradient coils |
1Dept. of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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The matrix gradient coils are showing its potential in offering high flexibility in generating customized spatial magnetic fields. However, the high demands on the amplifiers might become unacceptable for conventional one-coil one-amplifier drive method. We developed a 12 channel gradient driver system integrated with multi-channel switches for matrix gradient coils to drive a higher number of coil elements. The system was tested successfully with a home-built matrix gradient coil with its channels grouped in 12 clusters. |
| 3549 | Computer #26 |
Variation in strain characteristics for multiscale multi-physics models of a 1.5T conduction cooled MRI system based on a 36 filament MgB2 composite wire |
1Department of Mechanical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Department of Physics, Case Western Reserve University, Cleveland, OH, United States, 3Hyper Tech Research Inc., Columbus, OH, United States |
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A higher field (>1.5T) MRI magnet system is usually constructed with composite superconducting wire. Usually, modeling of the strain development of this magnet system requires approximation of the material property of composite Magnesium diboride wire using the simple rule of mixture (ROM). The Rule of Mixture (ROM) is a straight forward and simple technique but the underestimation of the strain development may affect the accuracy of the analysis. This study compares the variation in hoop strain development as three different numerical homogenization methods are employed to estimate the material property of the composite wire. |
| 3550 | Computer #27 |
Imaging with a high-channel matrix gradient coil |
1Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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Matrix gradient coils consist of many elements that can be combined to produce a wide variety of magnetic fields for spatial encoding and shimming applications. In this work, first imaging results are presented using a newly constructed 84-channel actively shielded matrix gradient coil. The coil elements are combined in groups and driven by 12 additional gradient power amplifiers to produce approximately linear gradient fields. Images are of comparable quality to the standard clinical system with relatively little calibration of the matrix coil. The integrated system is extremely flexible and enables new research into novel encoding techniques. |
| 3551 | Computer #28 |
Analysis and Prediction of Gradient Response Functions under Thermal Load |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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Temperature dependent changes of gradient impulse response functions are analyzed by measurements with a recently proposed continuous field camera and the resulting data is used in a locally linear model approach to predict impulse response functions based on temperature data. |
| 3552 | Computer #29 |
Peripheral Nerve Stimulation Thresholds of a High Performance Insertable Head Gradient Coil |
1Robarts Research Institute, Western University, London, ON, Canada, 2Medical Biophysics, Western University, London, ON, Canada, 3Dept. of Radiology, Stanford University, Stanford, CA, United States |
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A high performance insertable head gradient was evaluated for peripheral nerve stimulation and found to have PNS thresholds several times higher than body gradients and equal to or exceeding existing head gradients. The most sensitive axis (Y) had a threshold of ΔGmin = 108 ± 4 mT/m and SRmin = 156 ± 9 T/m/s. This rapidly insertable coil has the hardware capability to reach ∆Gmax of 120mT/m single axis and 400mT/m triple axis with presently available clinical gradient amplifiers, meaning extremely high hardware performance but also that PNS thresholds are reached on most axes. |
| 3553 | Computer #30 |
Gradient input optimization based on the measured system frequency response |
1Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland, 2Translational Neuromodeling Unit, Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland |
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Accurate gradient time-courses are crucial for MRI, yet actual waveforms generally deviate from ideal. We here propose to treat the task of finding the ideal gradient input for a targeted output gradient waveform as a case-by-case optimization problem, based on an LTI model of the gradient system. The method is aimed to achieve optimal gradient waveform fidelity that a given gradient system is capable of producing, considering both bandwidth and amplitude/slew rate limitations. We perform the optimization for an EPI and a spiral sequence and compare the resulting output to using non-optimized input on measured k-space trajectories. |
| 3554 | Computer #31 |
Vibroacoustic Noise Reduction in High Performance Head Gradient Coils Using Ceramic Inserts |
1Dept. of Radiology, Stanford University, Stanford, CA, United States, 2Robarts Research Institute, The University of Western Ontario, London, ON, Canada |
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We hypothesized that ceramic inserts will reduce sound pressure levels (SPLs) in high performance head gradient coils. We used realistic multi-physics modeling methods (previously validated by experiments) to investigate this hypothesis, and in particular to evaluate vibroacoustic reductions as a function of ceramic insert geometry and frequency of excitation. Averaged over the range 0-3000Hz, we demonstrate a maximum overall SPL reduction of 10.9dB, with a substantially higher reduction in the high frequency regime (2000-3000Hz) of 20.7dB. We show that a uniform 15mm thick cylindrical insert is a practical design that yields the majority of the acoustic reduction benefit. |
| 3555 | Computer #32 |
Continuous SWIFT on a whole-body 7T system: Initial phantom and in vivo images |
1German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland, 3Diagnostic and Interventional Radiology, University Medical Center Ulm, Ulm, Germany |
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Simultaneous excitation and acquisition is a promising approach to acquire MR images using very low transmission power. This concept is also well-suited for imaging tissues and materials with ultrashort T2* relaxation times since no echo time exists. In this work, a cSWIFT hardware setup, pulse sequence, and reconstruction were designed for and implemented on a whole-body 7T system. Spectroscopy and imaging of phantoms and in vivo imaging of the human forearm were successfully performed. Feasibility of cSWIFT with the implemented setup was demonstrated. |
| 3556 | Computer #33 |
Portable Magnet Design Optimization for Brain Imaging without Gradient Coils |
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Biophysics, Harvard University, Cambridge, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Department of Physics, Harvard University, Cambridge, MA, United States, 5Harvard-MIT Division of Health Sciences Technology, Cambridge, MA, United States |
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The development of a low-cost portable MRI scanner for brain imaging could address the need for imaging at unconventional sites. We previously presented an appropriate method for 3D imaging in a portable magnet without gradient coils. In-plane image encoding was demonstrated using the natural field variation of a rotating prototype magnet. However, the magnet diameter must be increased for human brain imaging and the built-in encoding field should be tailored to improve image resolution uniformity. We present a method for designing an optimized magnet for this application using the Genetic Algorithm, and evaluate a chosen design via image simulations. |
| 3557 | Computer #34 |
Very low field MRI setup for brain imaging |
1SPEC, CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France |
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Mixed sensors are at present competitive with classical tuned coils for the detection of MRI signals on a very low field range. A very low field head MRI system is developed without pre-polarization technique nor magnetic shielding room. Homogeneity of the system and gradients were characterized. A homogeneity of 115 ppm was achieved in a quasi-open configuration. Linearity of the gradients was verified. The amplitude of each gradient was 100 times lower than at high field but sufficiently high to achieve a resolution of 2 mm x 2 mm x 2 mm. |
| 3558 | Computer #35 |
Wireless Powering Using MRI Pulse Sequences |
1Electrical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin-Madison, Madison, WI, United States |
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We present models for wirelessly powering implants using the transmit RF excitation for MRI. Detailed models were developed for all hardware components of the transmit chain, including actual MRI sequences. Candidate pulse sequences were compared to predict how wireless powering could operate synchronously with imaging. The methods are useful in designing and optimizing wireless powering inside the MRI scanner. |
| 3559 | Computer #36 |
ZT-AC: Zero TE based PET/MR attenuation correction |
1GE Global Research, Munich, Germany, 2GE Global Research, Bangalore, India, 3GE Global Research, Niskayuna, NY, United States, 4University of California San Francisco, San Francisco, CA, United States |
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We describe a novel PET/MR attenuation correction (AC) method based on zero TE MR imaging that is fast, robust and accounts for bone. The method, termed ZT-AC, was tested for N=10 PET/MR patients in the head and compared relative to gold-standard CT-AC and atlas-based AC methods. |
| 3560 | Computer #37 |
Evaluation of ZTE localization accuracy for PET/MR hardware attenuation correction |
1GE Healthcare, Zurich, Switzerland, 2GE Healthcare, Stanford, CA, United States, 3University Hospital, Zurich, Switzerland |
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One challenge of PET/MR imaging is the correction of photon attenuation caused by hardware in the field-of-view. For the particular case of MR local coil attenuation, a solution based on stored templates is provided by commercially available clinical PET/MR systems. This solution, however, is limited to rigid coils docked in a pre-defined position. A more general method encompassing other coil types would be desirable to improve the accuracy of PET images. The goal of the present study is to investigate the accuracy of fast ZTE acquisitions for the correction of local coil attenuation. |
| 3561 | Computer #38 |
Implementation of an 84 Channel Actively Shielded Matrix Gradient Coil |
1Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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In this abstract, we present an 84 channel actively shielded matrix gradient coil. This coil was built and integrated into our 3T MRI scanner. Functionality and characterization measurements such as high voltage tests, eddy current and field map measurements were successfully performed. This system allows for generating spatial encoding fields in a highly flexible fashion, which enables the development of novel imaging techniques. |
| 3562 | Computer #39 |
Evaluation of Multileaf Collimator performance in high magnetic fringe fields for MRI-Linac development |
1Ingham Institute for Applied Medical Research, Liverpool, Australia, 2Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, Australia, 3Department of Medical Physics, Cancer Therapy Centre, Liverpool Hospital, Liverpool, Australia, 4South Western Sydney Clinical School, University of New South Wales, Liverpool, Australia, 5Radiation Physics Laboratory, Sydney Medical School, The University of Sydney, Camperdown, Australia |
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Hybrid systems combining an MRI with a linear accelerator for image guided radiation treatment are being implemented world-wide. As part of our own development we investigated the effect of increasing magnetic field on the performance of a multi-leaf collimator (MLC) motor and encoder from the treatment head of a linear accelerator. Measurements were made at various locations in the fringe field of a 3T scanner with the MLC positioned to replicate both in-line and perpendicular treatment beam to B0 directions. Results show a static field threshold and speed reduction which is position dependent which can be improved significantly with shielding. |
| 3563 | Computer #40 |
Adaptive Integrated Parallel Reception, Excitation, and Shimming (iPRES) with Bipolar Junction Transistors. |
1Brain Imaging and Analysis Center, Duke University, Durham, NC, United States |
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An integrated parallel reception, excitation, and shimming coil array with N DC shim loops within each RF coil, termed iPRES(N), improves the shimming of local B0 inhomogeneities relative to the original iPRES design with one loop per coil, but requires N times more power supplies which adds complexity and cost. A new adaptive iPRES design is proposed that uses bipolar junction transistors to generate different DC current paths, and hence different B0 fields for local shimming, within each coil using one power supply per coil, thus maintaining the shimming flexibility of iPRES(N) while reducing the number of power supplies. |
| 3564 | Computer #41 |
WITHDRAWN |
1Brain Imaging and Analysis Center, Duke University, Durham, NC, United States |
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| 3565 | Computer #42 |
Lenz lenses: RF field amplification and increased sensitivity using passive inductive elements |
1Department of Radiology and Nuclear Medicine, St. Olav's University Hospital, Trondheim, Norway, 2IMTEK - Laboratory for Simulation, University of Freiburg, Freiburg, Germany, 3Institute of Microstructure Technology, Karlsruhe Institute of Technology, Karlsruhe, Germany, 4IMTEK - Laboratory for Microactuators, University of Freiburg, Freiburg, Germany |
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Lenz lenses are discrete elements that focus magnetic flux by virtue of their configuration. By the principle of reciprocity, Lenz lenses may be used to increase both B1-field strength and receiver sensitivity in an NMR experiment. We present the theory that describes Lenz lenses and their geometrical optimization, plus some preliminary experimental results that demonstrate a three-fold increase in local SNR. |
| 3566 | Computer #43 |
A prototype low field dental MRI system |
1Immunity, Infection and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom, 2University of Wurzburg, Wurzburg, Germany |
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A prototype dental MRI magnet system has been designed, developed and tested. Initial results show the magnet design agrees well with the predicted field using eletromagnetic modelling. |
| 3567 | Computer #44 |
Comparison of preemphasis based on a broadband filter vs. a standard exponential model for higher-order dynamic shimming |
1FMRIB centre, NDCN, University of Oxford, Oxford, United Kingdom, 2Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland, 3Magnetic Resonance, Siemens Healthcare GmbH, Erlangen, Germany |
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Traditionally, shim preemphasis filters to compensate for eddy current fields have consisted of a sum of exponentially decaying terms. It has recently been proposed to instead implement a non-parametric preemphasis filter based on the shim impulse response function. This can address features that are not captured with the exponential model, such as oscillatory responses. We here compared the two preemphasis approaches for higher-order dynamic shim updating. The non-parametric filter yielded an improved frequency response of the system and about 10 ms faster shim settling, as well as suppression of field oscillations after a shim step. |
| 3568 | Computer #45 |
COSI Magnet: Halbach Magnet and Halbach Gradient Designs for Open Source Low Cost MRI |
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine, Berlin, Germany, 2Institute of Physics, University of Mainz, Mainz, Germany, 3Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine, Berlin, Germany, 4MRI.TOOLS GmbH, Berlin, Germany |
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Cost effective open source imaging (COSI) is a collaborative initiative currently building an affordable low field open source MR scanner with the technical documentation available at www.opensourceimaging.org. As part of this initiative uniform Halbach magnets have been evaluated in absolute B0, field homogeneity, magnet mass and costs. Halbach quadrupoles are introduced, that produce an adjustable constant gradient field for spatial encoding removing the need for high power gradient amplifiers. Combining these efforts an imaging magnet (B0=0.3T, di=180mm) design is presented that can incorporate a Halbach gradient of 157mT/m. The results are encouraging for low cost low field MR applications. |
| 3569 | Computer #46 |
Crosstalk between gradient coils |
1School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Australia, 2Department of Energy, Politecnico di Torino, Torino, Italy |
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In MRI, gradient coil switching generates eddy currents in surrounding conductors including intra-coil eddy currents in the surrounding gradient coils (crosstalk). In order to investigate the intra-coil eddy currents, a set of gradient coils with differing track widths has been designed for use in a cylindrical MRI system. It was found that the surrounding coils with wide tracks produced significantly larger eddy currents than the cold shield. It is therefore necessary to take into account the crosstalk between coils when evaluating coil performance. We found that the optimal track width to use in gradient coil design is around 14 mm. |
| 3570 | Computer #47 |
Theoretical investigation of gradient pulse alterations for acoustic noise reduction in an MRI-LINAC system |
1The University of Queensland, Brisbane, Australia |
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A theoretical acoustic noise control method was proposed through gradient pulse alterations. This method can remove the resonant-frequency components of the gradient pulse and keep the pulse form. This method is easily implemented without reassembling the MRI system elements. Simulation shows that the noise reduction effect using this method is significant. Imaging quality will be evaluated on future experimental measurements. |
| 3571 | Computer #48 |
The forgotten planar gradient coil |
1Department of Electrical Engineering, Universitas Dian Nuswantoro, Semarang, Indonesia |
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This work present two methods for designing simple and compact planar coils. The length of a constant wire width is minimized using Euclidian and Manhattan distance. Euclidian coils exhibit smooth patterns of slightly lower resistance than that of square-shape coils obtained using Manhattan distance. Manhattan coils show straight conductors which minimizes the force and facilitate the coil manufacturing. The coil sensitivity increases up to 1.8 times when placed in the iron poles but in detriment of the coil slew rate. Compact transverse coils architected using both distance minimization induces a residual eddy current smaller than 0.05% within the DSV. |
| Exhibition Hall | Tuesday, May 10, 2016: 17:00 - 18:00 |
| 3572 | Computer #1 |
In-Bore MRI-Guided Transperineal Prostate Biopsy using 4-DOF Needle-Guide Manipulator |
1Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States, 2Department of Mechanical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States, 3Acoustic MedSystems Inc., Savoy, IL, United States, 4Department Of Mechanical Engineering, Johns Hopkins University, Baltimore, MD, United States |
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We present the clinical feasibility of our MRI-compatible 4-DOF needle-guide manipulator for in-bore MRI-guided transperineal prostate biopsy. Total 11 men were biopsied in a 3T MRI scanner using this manipulator. All 11 procedures were successfully performed in 102.6±24.5 minutes with targeting errors of 4.9±2.9 mm. The targeting errors were consistent with other clinical studies. Pathology results confirmed prostate cancer with Gleason score ≥ 6 in 5/6 men with previous negative TRUS biopsies, and upgraded 2/5 men on active surveillance to clinically significant cancer with Gleason score 7. In conclusion, In-bore MRI-guided prostate biopsy using the manipulator was feasible. |
| 3573 | Computer #2 |
Motion compensated high resolution MR Imaging of Vagus and Recurrent Laryngeal Nerves with Novel Phase-based Navigation Sequences |
1MR R&D, Siemens Healthcare, Boston, MA, United States, 2Radiology, Brigham and Women's Hospital, Boston, MA, United States, 3Endocrine Surgery, Brigham and Women's Hospital, Boston, MA, United States |
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Diagnostic imaging of the recurrent laryngeal (RLN) and vagus nerves (VN) could help in surgical planning and in minimizing the risk of damage to the nerves. However, imaging these nerves is technically challenging due to their size, location, and physiological motions such as breathing and swallowing. The RLN and VN can be visualized on the CISS and T2 TSE, however with a novel phase navigator, the nerves are better delineated on the motion-compensated T2 TSE compared to the CISS which is un-navigated. |
| 3574 | Computer #3 |
Geometry of Basal Ganglia nuclei in QSM and Histology in Parkinson’s disease brains |
1Weill Cornell Medical College, New York, NY, United States, 2Yale School of Medicine, Yale University, New Haven, CT, United States |
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Quantitative susceptibility mapping (QSM) provides a quantitative MRI contrast, which reflects the local iron concentration. Thus, QSM allows to determine the geometries of iron-rich deep grey matter nuclei including substantia nigra (SN) and subthalamic nucleus (STN). These basal nuclei are of particular interest in Parkinson’s disease. However, the measured dimensions need to be validated in histology using post-mortem human brain tissue. In this work, we show the concordance of the geometries measured in QSM and histology using Perls’ iron stain, which opens the door to use QSM as a pre-surgical mapping for deep brain stimulation targeting the STN. |
| 3575 | Computer #4 |
Multi-parametric MRI Characterization of a Polymer Gel Dosimetry Phantom for Non-Invasive 3D Visualization of Radiation Deposition in Gamma Knife Therapy |
1Philips Medical Systems, Dallas, TX, United States, 2Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 3Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, United States |
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Radiation therapy aims to maximize dose delivery to tumor areas while minimizing the exposure to healthy tissue. Quality control is required to ensure that the delivered dose closely matches the calculated dose. We performed a patient-specific quality assurance for cranial radiotherapy using MRI to visualize delivered radiation dose. We utilized an anthropomorphic 3D printed head phantom filled with polymer gel that was scanned before and after exposure to Gamma Knife irradiation. Irradiation changed the polymerization state of the gel and multi-parametric (T1, T2, MR Spectroscopy, CEST) quantitative dose-imaging maps were generated that may lead to optimized patient-specific dose delivery planning. |
| 3576 | Computer #5 |
TOLD MRI Validation of Reversal of Tumor Hypoxia in Glioblastoma with a Novel Oxygen Therapeutic |
1UT Southwestern Medical Center, Dallas, TX, United States, 2NuvOx Pharma, Tucson, AZ, United States, 3Nucleus Networks, Melbourne, Australia, 4William Buckland Radiotherapy Centre, Melbourne, Australia, 5Moffitt Cancer Center, Tampa, FL, United States, 6Alfred Hospital, Prahran, Australia, 7Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 8Medical Imaging, The University of Arizona, Tucson, AZ, United States |
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Glioblastoma multiforme (GBM) is known to be a hypoxic tumor and hypoxia adversely affects response to radiation therapy. Dodecafluoropentane emulsion (DDFPe) can improve oxygenation. Tissue oxygen level dependent (TOLD) MRI is an oxygen sensitive imaging technique which is used in this study to assess the improvement of oxygenation after administration of DDFPe. Two different doses were tested and each showed decreased T1 indicating improved oxygenation. |
| 3577 | Computer #6 |
Towards DWI Guidance of Percutaneous Biopsies using Dual Echo Steady State Sequence: Qualitative Assessment in Liver |
1Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 2Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States |
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Acquisition of a viable tissue sample is critical to success of a biopsy. DWI could help differentiate between viable and necrotic tissue during the procedure, however, EPI-DWI is not suitable in a percutaneous-biopsy setting due to geometric distortions. DW Dual Echo Steady State (DESS) sequence allows acquisition of 3D undistorted DWI images. This study evaluated the application of DW-DESS during an MR-guided liver biopsy in two patients. Using single breath-hold acquisition, DW-DESS image depicted a liver lesion sharper and less distorted than EPI-DWI. DW-DESS also allowed DWI in the presence of a biopsy needle without distortions of EPI. |
| 3578 | Computer #7 |
Scannerless real-time MRI |
1Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States, 2Mechanical Engineering, Boston University, Boston, MA, United States |
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MRI can provide favorable image quality for image-guided interventions, but both magnetic field of the scanner and limited patient access inside the bore impose many limitations on image-guidance endeavors. The aim of this work was to estimate MRI of respiratory organ motion outside the scanner, which allows for a wider range of interventional applications. A single-element ultrasound transducer was used as a surrogate for the MR scanner outside the bore, after the correlation between both signals had been learned in a preceding training phase. Validation of estimated MR images outside the bore was performed using tracked 2D ultrasound. |
| 3579 | Computer #8 |
Real-Time Golden Angle Radial iSSFP for Interventional MRI |
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 2Biomedical Physics, University of California, Los Angeles, Los Angeles, CA, United States |
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Real-time visualization is crucial to the success of MRI-guided minimally invasive cancer interventions. In this work we combine iSSFP with a golden-angle(GA) ordered radial trajectory and non-Cartesian parallel imaging to create a new real-time MRI sequence with good tissue contrast while suppressing bSSFP banding artifacts. Phantom and volunteer data were acquired and reconstructed using a combined sliding-window SPIRiT algorithm, at different frame rates, showing the capability of the sequence to achieve real-time imaging. These advantages of GA Radial iSSFP show its potential for improving real-time MRI-guided interventions. |
| 3580 | Computer #9 |
The Development of Tissue Mimicking Gels |
1Radiology, University of Kentucky, Lexington, KY, United States, 2Anatomy & Neurobiology, University of Kentucky, Lexington, KY, United States, 3Smilow Center for Translational Research, University of Pennsylvania, Philadelphia, PA, United States |
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Developing tissue mimicking materials can be helpful in reducing the cost and duration of experiments which otherwise require animals. We tested a variety of agarose gels of different gel strength as suitable tissue mimicking material for convection enhanced delivery. The results demonstrate a significant difference in infusion volume and we relate that, through MR measurements, to the mechanical stiffness of the gels. |
| 3581 | Computer #10 |
A four-layer boundary element model for MRI-guided transcranial magnetic stimulation |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 2Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland |
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MRI-guided targeting and dosing has the potential increase the consistency and efficacy of transcranial magnetic stimulation (TMS). We propose a boundary element method (BEM) approach for estimating the TMS-induced cortical electric fields (E-fields). The method can be applied based on standard T1/T2-weighted MRI data and can incorporate the cerebrospinal fluid (CSF) as a separate conductivity compartment. Our results show that the CSF layer may increase the estimated E-field amplitudes up to 25%. The effect of the CSF depends on the location and orientation of the TMS coil/target in a rather intricate manner, highlighting the importance of individualized, realistically shaped models. |
| 3582 | Computer #11 |
Measurement and Simulation of Susceptibility Artifacts in Variable-TE Radial MRI: Application in an MR-safe Guidewire |
1Dept. of Radiology - Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2MaRVis Medical GmbH, Hannover, Germany, 3German Cancer Consortium (DKTK), Heidelberg, Germany, 4German Cancer Research Center (DKFZ), Heidelberg, Germany |
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A simulation framework is presented to optimize radial acquisition schemes with variable echo times which are designed to minimize the directional anisotropy of the artifact of an MR-safe guidewire. The simulation results are compared to measurements. We could theoretically and experimentally verify that the homogeneity of the artifact can be improved via the variable-TE method. |
| 3583 | Computer #12 |
First steps towards concurrent, high rate imaging and MR tracking using an inertial measurement unit (IMU) |
1GE Global Research Center, Niskayuna, NY, United States, 2Memorial Sloan Kettering Cancer Center, New York City, NY, United States |
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Tissue motion during MR guided interventional procedures leads to the desire to perform simultaneous high speed tracking of the surgical instrument and imaging. In this work, a novel approach for concurrent tracking and imaging, based on an inertial measurement unit (IMU) and technology from plane/missile tracking, is presented. While using infrequent position updates for the IMU (that could be provided by MR tracking), we have showed fast tracking (166Hz) of the IMU sensor with ~2mm rms error. |
| 3584 | Computer #13 |
Interventional device visualisation using the coupling mode of a PTx transmit array |
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom |
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We propose a novel method to visualise guidewires in interventional MRI procedures using the coupling mode of a PTx array. |
| 3585 | Computer #14 |
Automatic high temporal and spatial resolution position verification of an HDR brachytherapy source using subpixel localization and SENSE |
1Department of Radiotherapy, UMC Utrecht, Utrecht, Netherlands, 2Image Sciences Institute, UMC Utrecht, Utrecht, Netherlands |
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In order to verify the positions of a high-dose-rate (HDR) brachytherapy source during treatment, fast imaging and post-processing are needed. To get high temporal resolutions, the use of lower spatial resolutions in combination with subpixel source localization and the use of parallel imaging were introduced. MR artifacts were simulated and correlated to the experimentally obtained artifacts (by phase-only cross correlation) to determine the position of the HDR source. It was shown that the described method was fast enough for localization of an HDR brachytherapy source in real-time and high accuracy and precision (submillimeter scale) were achieved. |
| 3586 | Computer #15 |
Hindered diffusion of Gadolinium-based Contrast Agents in rat brain extracellular micro-environment after ultrasound-induced delivery |
1CEA/DSV/I2BM/NeuroSpin, Gif Sur Yvette, France, 2Department of Neuroscience, Imaging and Clinical Sciences, G. D'Annunzio, University of Chieti and Pescara, Chieti, Italy, 3Image Guided Therapy, Pessac, France, 4Université Lyon 1, Lyon, France |
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We present here a new method to study the diffusion process of Gadolinium-based Contrast Agents within the brain extracellular space after the artificial Blood-Brain Barrier opening induced by ultrasound. Four compounds were tested (MultiHance, Gadovist, Dotarem and AGuIX). By estimating the Free Diffusion Coefficients from in vitro studies, and the Apparent Diffusion Coefficients from in vivo experiments, an evaluation of the tortuosity (λ) in the right striatum of 11 Sprague-Dawley rats has been performed. The values of λ are in agreement with literature and demonstrate that the chosen permeabilization protocol maintains the integrity of brain tissue. |
| 3587 | Computer #16 |
3D Histogram Analysis of Apparent Diffusion Coefficient Maps Predicts Relief of Fibroid Symptoms after MR Imaging–guided High-Intensity Focused Ultrasound Ablation |
1Department of Radiology, the First Affiliated Hospital of Xi'an Jiaotong University, xi'an, China, People's Republic of, 2MR Marketing, Philips Healthcare, xi'an, China, People's Republic of, 3MR Therapy Clinical Science, Philips Healthcare, Seoul, Korea, Republic of |
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The aim of the study was to investigate the variation among screening fibroids through analysis of ADC histogram, in order to predict fibroids residual NPV proportion (residual NPV%=NPV at 6 months follow up/ NPV immediately after treatment ) and patients Symptom Severity Score (SSS). Thirty five patients who accepted MRgHIFU ablation were divided into group 1 (residual NPV%≥20%) of 19 patients and group 2 (residual NPV%＜20%) of 16 patients, respectively. The SSS of patients were obtained at two time-point, screening and 6 months follow up. ADCmean, ADCq, kurtosis and skewness are derived from ADC histogram. The results showed that values of ADCmean, ADCq and kurtosis were significant difference between two groups. The average SSS reduction of group 1 between pre and post treatment was more obvious than that of group 2. Therefore, histogram analysis of ADC maps can provide the quantitative information to predict fibroids ablation outcome and patients symptom relief, which may be indicated as a useful screening tool to guide patients selection for MRgHIFU ablation. |
| 3588 | Computer #17 |
Real-time MRI-guided interventions using rolling-diaphragm hydrostatic actuators |
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 2Biomedical Physics, University of California, Los Angeles, Los Angeles, CA, United States, 3Mechanical and Aerospace Engineering, University of California, Los Angeles, Los Angeles, CA, United States |
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In this work we investigate a new rolling-diaphragm-based hydrostatic actuator design to achieve smooth remote manipulation without fluid leakage for MR-compatible robotic systems. We show that the actuators exhibit negligible impact on MR image fidelity and SNR, the actuator provides a linear displacement response over the fluid lines, and we were able to use the master/slave actuator pair to insert and retract the needle in a phantom with no leakage and no noticeable friction issues. Our new rolling-diaphragm hydrostatic actuators can potentially enable physicians to remotely perform real-time MRI-guided interventions. |
| 3589 | Computer #18 |
A Simple Scanner Control Technique for Device Localization during MRI-Guided Percutaneous Procedures |
1Electrical Engineering, Lakehead University, Thunder Bay, ON, Canada, 2Thunder Bay Regional Research Institute, Thunder Bay, ON, Canada, 3Medical Imaging, University of Toronto, Toronto, ON, Canada, 4Hospital for Sick Children, Toronto, ON, Canada |
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An experiment demonstrates a simple technique for a clinician operator to interactively align scan planes to an interventional device within the scan room during an MRI guided procedure. Input is collected using foot pedal switches to select axial/device intersection points to specify a virtual line of best fit about which auxiliary views are aligned automatically. Volunteer operators position a biopsy needle within an ex vivo porcine specimen while interactively tracking the needle position and measurements are taken to assess the technique's efficiency. |
| 3590 | Computer #19 |
Experimental study of MR Compatible RF Hyperthermia System |
1Electronics and Information Engineering, Korea University, Seoul, Korea, Republic of, 2The MRI Team, Korea Basic Science Institute, Cheongju, Korea, Republic of |
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Many reports suggest that hyperthermia is very effective treatment for tumor therapy. In this work, MR compatible RF hyperthermia system is presented for a 3.0 T MRI. Phantom and animal experiments have been conducted and the results compared with the simulations results for tumor and tissue model. They are in very good coincidence with each other, which confirms the utility and feasibility of the MR compatible RF hyperthermia system with capacitive driving. |
| 3591 | Computer #20 |
Tracking of a Robotic Device by Controlling the Visibility of Markers from the Robot Control |
1University of Houston, Houston, TX, United States, 2University of Cyprus, Nicosia, Cyprus, 3Houston Methodist, Houston, TX, United States, 4Leiden University Medical Center, Leiden, Netherlands |
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Integrated control system of the manipulator and marker control is important for localization and tracking of multiple optically detunable MR markers on MR-compatible manipulators. Selecting which markers are visible on MR images by the motion of the maneuvering portion of the MR-compatible manipulators allows unambiguous identification of a combination of markers and simplifies both the data acquisition and the post processing. This proposed technique can be employed to track multiple marker positions on interventional devices such as the steerable catheters and the end-effectors of the MR-compatible manipulator. |
| 3592 | Computer #21 |
Visualization of interventional devices by transient, local magnetic field alterations using bSSFP sequences |
1University Hospital Tübingen, Tübingen, Germany |
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A technique for the visualization of interventional devices by use of transient, local magnetic field alterations and bSSFP sequences is presented. It allows the generation of distinct artifacts with controllable dimension. The instrument is visualized in the phase image obtained in the same scan as the undisturbed anatomical image. Localization is done by subsequent superposition. |
| 3593 | Computer #22 |
On Demand Reprogramming of MR Sequence Parameters Using MatMRI |
1Thunder Bay Regional Research Institute, Thunder Bay, ON, Canada, 2Electrical Engineering, Lakehead University, Thunder Bay, ON, Canada, 3Philips Healthcare, Toronto, ON, Canada, 4Computer Science, Lakehead University, Thunder Bay, ON, Canada, 5University of Toronto, Toronto, ON, Canada, 6The Hospital For Sick Children, Toronto, ON, Canada |
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For dynamic studies, it is often desirable to adjust parameters in “real time” depending on decisions made by user-defined algorithms. We performed a modification to the software tool MatMRI to develop a method that allows changing on demand multiple MR sequence parameters. We present results of this new method when applied to the modification of sequence parameters for MR-Acoustic Radiation Force Imaging. Our results demonstrate that it is feasible to reprogram MR sequence parameters dynamically using existing technology for the control of scanners. |
| 3594 | Computer #23 |
Efficient respiratory navigator-based 4D MRI |
1Philips GmbH, Innovative Technologies, Research Laboratories, Hamburg, Germany |
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4D image data are used in radiation therapy planning to estimate motion of the tumor or regions at risk. Today 4D CT is commonly used for this purpose. Due to better soft tissue contrast and quantitative and functional imaging, a clinical demand for MRI in therapy planning exists. Consequently, there is also a growing interest in 4D MRI techniques. A scan-time-efficient 4D MRI method utilizing the MRI Navigator as motion sensor with high geometric fidelity is proposed. |
| 3595 | Computer #24 |
MR imaging patterns of Cholangiocarcinoma and post-intervention features: A case-based approach |
1Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States |
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Cholangiocarcinoma may demonstrate typical imaging manifestations and common patterns of organ involvement, guiding diagnosis, and facilitating imaging follow up after therapy. Adequate knowledge of tumoral biology in cholangiocarcinoma and current image-guided therapeutic approaches, along with imaging appearance of cholangiocarcinoma before and after image-guided interventions is crucial for adequate diagnosis and surveillance .MR imaging plays a key role for patient management, assessing therapy response and patient surveillance. |
| Exhibition Hall | Tuesday, May 10, 2016: 17:00 - 18:00 |
| 3596 | Computer #25 |
Real-Time Monitoring of Focused Ultrasound Induced Inertial Cavitation on Microbubbles by Using Gradient Echo MRI: in Vitro and in Vivo Experiments |
1Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu City, Taiwan, 2Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei, Taiwan |
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This study aims to real-time monitor inertial cavitation on microbubbles (MBs) while transmitting focused ultrasound (FUS) with various duty cycle and pulse repetitive frequency (PRF) by gradient echo MRI. For in vitro experiments, with increasing duty cycle, more significant signal intensity (SI) changes or prolonged SI drop duration were shown. For in vivo experiment, two SI drop peaks were observed, reflecting the two IC events. In conclusion, FLASH has been proved to be a useful technique for real-time monitoring of IC when transmitting FUS pulses to MBs for in vitro and in vivo experiments. |
| 3597 | Computer #26 |
Multi-Contrast Late Enhancement Out-Performs Conventional Late Gadolinium Enhancement for Myocardial RFA Lesion Characterization |
1Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada, 3Sheikh Zayed Institute for Pediatric Surgical Innovation, Washington, DC, United States |
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In this work we evaluated the quality and accuracy of myocardial RFA lesion visualization using the MCLE sequence. To compare MCLE to the standard LGE, we imaged 29 acute lesions in 11 pigs. Lesion sizes measured from each set of images were highly correlated, yet MCLE consistently achieved higher CNR than LGE. Our relaxometry maps from MCLE suggested a dramatic variation in T1 after contrast injection, which will alter the optimal TI for LGE. Therefore, we demonstrated that MCLE, with the varied TIs in each acquisition, is a more robust sequence for visualizing even the most subtle lesions. |
| 3598 | Computer #27 |
Improved Thermometry Based on a Fast Spin Echo Sequence |
1GE Healthcare, Haifa, Israel |
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A time shifted Fast Spin Echo (FSE) thermometry sequence which is insensitive to B0 inhomogeneity is used in conjunction with restricted FOV module and parallel imaging to reduce scan time and increase the number of slices. Up to 5 slices are acquired in 3 sec. This sequence works well on a clinical Focused Ultrasound brain system. The temperature signal to noise ratio (TSNR) of this FSE sequence is approximately 2 times higher than the conventional Gradient Echo (GRE) sequence used today. 3 to 5 slices are acquired in 3 sec, rather than 1 slice with GRE. |
| 3599 | Computer #28 |
Prostate Focal Prostate Laser Ablation under MRI Guidance |
1College of Engineering, University of Georgia, Athens, GA, United States, 2National Institutes of Health, Bethesda, MD, United States, 3Philips Research North America, Briarcliff Manor, NY, United States |
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MRI-guided focal laser ablation (FLA) shows promise as an effective treatment for prostate cancer, but presents challenges related to accurate catheter positioning and ablation monitoring. A catheter positioning robot was designed to overcome these problems by positioning the catheter optimally for ablation and monitoring the ablation via MRI thermometry. A remote insertion guide allows the surgeon to perform the procedure without removing the patient from the MRI bore, saving time and increasing accuracy. Treatment planning software iteratively plans optimal catheter positioning. Preliminary tests show the robot can greatly improve efficiency and accuracy without sacrificing image quality. |
| 3600 | Computer #29 |
PRF Thermometry for Monitoring Small Temperature Changes during Very Long Thermal Therapies: Field Drift Compensation Using FID Navigators |
1Dept. of Radiology - Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2German Cancer Consortium (DKTK), Heidelberg, Germany, 3German Cancer Research Center (DKFZ), Heidelberg, Germany, 4Institute of Microstructure Technology, Karlsruhe Institute of Technology, Karlsruhe, Germany, 5Department of Neuroradiology, Neurocenter, University Medical Center Freiburg, Freiburg, Germany |
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Proton resonance frequency shift thermometry uses phase MR images to calculate temperature change in tissue during thermal therapies. Temporal and spatial changes of local magnetic field influence the phase images and can mimic temperature change. In order to correct for temperature errors due to magnetic field drift with time the FID navigators were used before and after imaging readout. Field-drift related phase slope during each repetition was calculated and used to correct the imaging data. This correction method is especially useful for the long thermometry procedures during which the temperature change is small and high temperature precision is needed. |
| 3601 | Computer #30 |
MR-guided focal laser ablation as primary treatment for prostate cancer: Preliminary results |
1Radiology, Radboud University Medical Center, Nijmegen, Netherlands, 2Urology, Radboud University Medical Center, Nijmegen, Netherlands |
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Focal therapy offers great hopes in terms of cancer control and decreased morbidity (i.e. impotence and incontinence) for patients with localized for low- and intermediate grade prostate cancer (PCa). Transrectal MR-guided focal laser ablation of newly diagnosed PCa was successfully performed in 5 patients. It was technically feasible and safe. PSA level decreased in all patients and follow-up MRI showed no residual or recurrent cancer; indicating local cancer control, without compromising with increased morbidity or a decrease in quality of life. Initial results are promising and more patients have to be included with longer follow-up. |
| 3602 | Computer #31 |
MR Thermometry-guided Prostate Hyperthermia with Real-time Ultrasound Beamforming and Power Control |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2Radiation Oncology, University of California San Francisco, San Francisco, CA, United States |
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We have developed and evaluated a real-time MR thermometry-guided system for acoustic power output and beam pattern control for prostate hyperthermia therapy. It was designed to be integrated with a commercial focused ultrasound ablation system and supports real-time ultrasound phase pattern switching and MR thermometry for monitoring and automated power adjustment. |
| 3603 | Computer #32 |
Zero TE based MR thermometry |
1GE Global Research, Munich, Germany, 2GE Global Research, Albany, NY, United States |
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Monitoring temperature changes in the human skull is important in clinical transcranial MR-guided focused ultrasound, as it can absorb a large amount of energy during sonication and thereby produce heat. We propose to extract relative temperature information from proton density weighted zero TE imaging and additionally calibrate the T1 signal contamination effect. |
| 3604 | Computer #33 |
Evaluation of common proton resonance frequency shift based MR Thermometry methods in the pancreas |
1University Medical Center Utrecht, Utrecht, Netherlands, 2Mathematical Institute of Bordeaux, Talence, France |
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MR-guided High Intensity Focused Ultrasound has recently been suggested to provide non-invasive alternative treatment options for pancreatic cancer patients. To successfully apply PRFS MR Thermometry in the pancreas motion correction techniques have to be applied. For other moving organs, several solutions have already been proposed to this end: gating, multibaseline and referenceless. However, due to specific properties of the pancreas, there was still a need to evaluate the performance of these methods in this organ. Our results show that all the evaluated techniques improved thermometry in the pancreas to a level that is sufficient to monitor thermal ablation. |
| 3605 | Computer #34 |
MR Guided Microwave Thermal Ablation: Guidance and Monitoring for Extending the Physics of Thermal Therapy |
1Biomedical Engineering, UW - Madison, Madison, WI, United States, 2Radiology, UW - Madison, Madison, WI, United States, 3Medical Physics, UW - Madison, Madison, WI, United States |
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Monitoring microwave ablation with thermometry could extend the application of this clinical procedure into territories where greater control is necessary to protect healthy tissue, such as the spine. MRI thermometry could also provide useful insights to generate and validate new thermal models based on the fundamentally different mode of dielectric heating utilized by microwave ablation. We present here a platform consisting of 1) a high power MR compatible microwave ablation system based on a FDA-approved design, 2) real-time applicator guidance during applicator insertion and 3) high frame rate MR thermometry and tissue monitoring. |
| 3606 | Computer #35 |
T2-based Temperature Monitoring in Bone Marrow for MR-guided Focused Ultrasound |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States |
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Current clinical protocols for bone treatments rely on measurement of the temperature change of adjacent muscle to estimate the temperature of the bone. In this study we have demonstrated for the first time that T2-based thermometry can be used in vivo to measure the heating in the marrow during bone ablation. The ability to monitor the temperature within the bone marrow allowed visualization of the heat penetration into the bone, which is important for local lesion control and treatment of osteoid osteomas. |
| 3607 | Computer #36 |
Monitoring of Stable Cavitation of Microbubbles by Using MRI |
1Biomedical Engineering and Environmental Science, National Tsing Hua University, Hsinchu, Taiwan, 2Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei, Taiwan, 3Electrical Engineering, Chang-Gung University, Taoyuan, Taiwan |
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Gas-filled microbubbles (MBs) can be locally cavitated by spatially focused ultrasound (FUS) to trigger stable cavitation (SC) and inertial cavitation (IC) to induce blood–brain barrier (BBB) opening ; therefore, magnetic resonance imaging (MRI) may provide useful imaging information to real-time monitor the process of FUS cavitation on MBs. In this study, a HASTE (Half Fourier Acquisition Single Shot Turbo Spin Echo) sequence was used to observe the signal changes during SC for in vitro experiments. Experiments with different acoustic pressure, pulse repetitive frequency, and duty cycle were performed to clarify the SC effect on MR images. |
| 3608 | Computer #37 |
The effect of sonication duration on ablation depth during MR-guided focused ultrasound of bone: acute findings with MR in a swine model |
1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States |
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One challenge in magnetic resonance guided focused ultrasound ablation of bone lesions is extending the ablation zone deep to the cortical surface in order to cover the full intramedullary extent of the lesion. Extension of the ablation zone is important for complete treatment of for example, osteoid osteomas, and improved local control of metastatic bone disease. This study used a swine model to compare differences in the depth of the ablation zone between two protocols using short versus longer sonications, respectively, while maintaining the same overall sonication energy (by adjusting acoustic power). |
| 3609 | Computer #38 |
Assessments of Flow Velocity Changes by Phase-Contrast MRI Near Acoustic Radiation Force Aggregated Bubbles |
1Biomedical Engineering and Environmental Sciences, Nation Tsing Hua University, Hsinchu, Taiwan, 2Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, 3Electrical Engineering, Chang-Gung University, Taoyuan, Taiwan |
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The aim of this study was to real-time assess flow velocity changes in the neighboring pixels of acoustic radiation force (ARF) aggregated bubbles by using phase-contrast MRI (PC-MRI). The flow velocity increased with the increase of microbubbles (MBs) concentrations, which might be attributed to the increase of aggregated bubbles size, narrowing the chamber diameter and thus presenting higher flow velocity. In conclusion, we verified the feasibility of using PC-MRI to assess flow velocity changes on pixels near ARF aggregated bubbles. In the future, a systematic investigation shall be conducted to comprehend the association between bubble size and the flow velocity. |
| 3610 | Computer #39 |
Prior Image based Temporally Constrained Reconstruction for Magnetic Resonance guided HIFU |
1Institute for Biological and Medical Imaging, Helmholtz Zentrum Munich, Munich, Germany, 2Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, London, United Kingdom, 3Supercomputer Education and Research Centre, Indian Institute of Science, Bangalore, India |
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Prior image based temporally constrained reconstruction (PITCR) algorithm was found to obtain accurate temperature maps with better volume coverage, and spatial, and temporal resolution than other algorithms using highly undersampled data in magnetic resonance (MR) thermometry. PITCR method is compared with the standard temporally constrained reconstruction (TCR) algorithm using ex-vivo pork muscle sample. It was seen that the PITCR method showed superior performance compared to the TCR approach with highly undersampled datasets. |
| 3611 | Computer #40 |
Phase artifact correction for improved ARFI displacement mapping using a short FID navigator |
1Dept. of Radiology - Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2German Cancer Consortium (DKTK), Heidelberg, Germany, 3German Cancer Research Center (DKFZ), Heidelberg, Germany, 4Institute of Microstructure Technology, Karlsruhe Institute of Technology, Karlsruhe, Germany |
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MR-guided acoustic radiation force imaging (ARFI) is used for the focal spot localization during high intensity focused ultrasound (HIFU) therapies. The acoustic radiation force related tissue displacement is measured with help of motion encoding gradients (MEG). While MEGs are sensitive enough to detect micrometer-scale displacement, the images acquired using MR-ARFI pulse sequences are often corrupted with artifacts. The method described uses very short FID navigator readout for correction of ARFI images without any manual interaction. ARFI displacement maps corrected by FID navigator have substantially less artifacts, 2.5 times higher SNR, and clearly visible HIFU focal spot. |
| 3612 | Computer #41 |
TREATMENT OF SMALL VASCULAR MALFORMATIONS USING MR GUIDED HIGH INTENSITY FOCUSED ULTRASOUND: PRELIMINARY RESULTS AFTER FOUR PATIENTS |
1Radiology, Stanford University, Stanford, CA, United States, 2Orthopaedic Surgery, Stanford University, Stanford, CA, United States |
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Low flow vascular malformations are typically treated with ultrasound-guided percutaneous sclerotherapy, but not all of these lesions are visible sonographically. MR guided focused ultrasound (MRgFUS) combines the ability of MRI to delineate these tumors with the use of FUS to ablate the tumor non-invasively. We report our technical and clinical results after using MRgFUS to treat four patients with small intramuscular low flow vascular malformations in the lower extremities. |
| 3613 | Computer #42 |
First clinical evaluation of real-time cardiac MR thermometry |
1Institut Hospitalier Universitaire : LIRYC Institut de Rythmologie et Modélisation Cardiaque, Bordeaux, France, 2Siemens France, Saint Denis, France, 3Mathematical Institute of Bordeaux, Bordeaux, France, 4Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France |
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Catheter ablation using radiofrequency is commonly used to treat cardiac arrhythmia. However, direct assessment of lesion formation with MRI thermometry during RF delivery may improve safety and efficiency of the therapeutic procedure. Despite recent studies demonstrating the feasibility on volunteers or animal models, there are no reports regarding the possibility of doing cardiac thermometry on patient in the context of arrhythmias. The purpose of the present study was to evaluate the uncertainty of temperature estimate on patients depicting potential arrhythmic episodes, which may alter the precision of the method relying on an ECG-triggered acquisition. |
| 3614 | Computer #43 |
Using simultaneous multi-slice imaging for PRFS thermometry |
1Radiotherapy, UMC Utrecht, Utrecht, Netherlands, 2Imaging Division, UMC Utrecht, Utrecht, Netherlands |
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PRFS thermometry is important for guidance of thermal therapies. Here we show that the thermometry sequence can be accelerated by the novel parallel imaging technique SMS-CAIPIRINHA and we compare it to an unaccelerated sequence and a SENSE accelerated sequence. Heating was applied by means of HIFU and LITT. A good agreement was seen between temperature curves from SMS-CAIPIRINHA and those from the unaccelerated sequence. Furthermore, the noise level was significantly lower compared to temperature curves from the SENSE accelerated sequence. |
| 3615 | Computer #44 |
Fully automatic in-vivo localization of LDR brachytherapy seeds for post-implant dosimetry using MR simulations and template matching |
1Image Sciences Institute, UMC Utrecht, Utrecht, Netherlands, 2Department of Radiotherapy, UMC Utrecht, Utrecht, Netherlands |
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We present a method which can accurately localize brachytherapy seeds in MRI using fast MR simulations and template matching. In 5 patients we correctly detected and localized 298 out of 307 seeds. Using this method an MRI-only approach to post-implant dosimetry will be possible, which should increase accuracy by not requiring CT to MRI image registration. |
| 3616 | Computer #45 |
Towards Real-Time In Vivo Volumetric MR Thermometry |
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 2Radiology & Medical Imaging, University of Virginia, Charlottesville, VA, United States, 3Radiology, Stanford University, Palo Alto, CA, United States |
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A rapid volumetric MR thermometry sequence, using a stack-of-spirals acquisition, was implemented on a real-time platform in order to support animal model experiments. The performance of the sequence, as measured by the maximum and mean recorded temperature as well as the sequence accuracy, was assessed against a clinically used 2DFT sequence in vivo. The use of efficient spiral trajectories supports rapid generation of volumetric thermometry maps and allows the visualization of the entire insonication as well as correlation with post-ablation imaging of lesion size and location. |
| 3617 | Computer #46 |
Accuracy of PRFS Temperature Mapping using Fast Interleaved Sequences for MR-HIFU Thermal Therapies |
1Tomographic Imaging, Philips Research, Hamburg, Germany, 2Oncology Solutions, Philips Research, Eindhoven, Netherlands |
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MR-HIFU therapies require stable PRFS-based temperature monitoring over the treatment duration (>30min). Drift effects may be corrected using independent temperature information e.g. based on T2 or T1 maps and simultaneously obtained using fast interleaved sequences. As interleaves may impact PRFS-accuracy, a dynamic on-off-interleaved sequence pattern is introduced to selectively measure their influence on the PRFS phase. The mechanism of the phase variations is explored using multiple variants of the interleaved sequence. It is shown that eddy currents induced during the interleaved sequences represent the main cause of the phase variation. The spatio-temporal characteristics of the effect are explored as a first step towards compensation. |
| 3618 | Computer #47 |
Automatic temperature control during MR guided catheter based radiofrequency ablation of the heart |
1Institut Hospitalier Universitaire : LIRYC Institut de Rythmologie et Modélisation Cardiaque, Bordeaux, France, 2Siemens France, Saint Denis, France, 3Image Guided Therapy, Bordeaux, France |
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Although catheter-based radiofrequency (RF) ablation is increasingly used to treat cardiac arrhythmia, insufficient temperature increase may lead to incomplete treatment whereas excessive local energy deposition may result in severe adverse effects (e.g. esophageal fistulas or tamponade due to steam pop). Since MR thermometry can monitor in real-time the temperature distribution in the cardiac muscle, automatic regulation of RF energy deposition from temperature images, using well established proportional, integral controller algorithms, may improve safety and efficiency of the therapeutic procedure. |
| 3619 | Computer #48 |
TREATMENT OF OSTEOID OSTEOMA USING MR GUIDED HIGH INTENSITY FOCUSED ULTRASOUND: PRELIMINARY RESULTS AFTER FOUR PATIENTS |
1Radiology, Stanford University, Stanford, CA, United States, 2Orthopaedic Surgery, Stanford University, Stanford, CA, United States |
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Osteoid osteoma is currently most frequently treated with CT guided radiofrequency ablation (CTgRFA), which is effective, but invasive and exposes the typical young patient population with osteoid osteomas to radiation. Our preliminary results are presented describing MR guided focused ultrasound (MRgFUS) for the treatment of patients with osteoid osteomas. As also reported in two European studies, in our experience, MRgFUS is effective at eliminating pain in these patients. These data form the basis for a proposed clinical trial directly comparing the safety and efficacy of MRgFUS and CTgRFA for treatment of osteoid osteoma. |
| Exhibition Hall | Tuesday, May 10, 2016: 17:00 - 18:00 |
| 3620 | Computer #49 |
55Mn Fiducial Markers for Automated Coil Localization and Sensitivity Determination for Use With Hyperpolarized 13C MRI |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States |
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RF coil arrays are critically important for hyperpolarized C-13 imaging because of increased sensitivity, coverage, and speed. A major limitation preventing widespread use of coil arrays is the difficulty measuring coil sensitivity profiles due to low C-13 natural abundance. We propose to solve this problem by using fiducial markers filled with 55Mn to determine coil location and then calculate coil sensitivities. We show proof-of-principle using a single RF coil and ethylene glycol phantom. Coil sensitivties derived from fiducial markers and quasitstatic calculations closely match those acquired through experiment. |
| 3621 | Computer #50 |
“Domino” Feed Board for Receive Coils |
1GE Healthcare, Aurora, OH, United States |
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The physical size of the on-coil electronics could be one of the major obstacles in building high density RF coils. First, there is a clear mechanical desire to reduce its size in order to make the coils lighter and thinner; second, bulky electronics placed on small loops can disturb the sensitivity profile; third, for MR-PET applications the RF coils, in addition to the requirements mentioned above, have to be transparent to PET radiation. In order to achieve these critical to quality objectives we propose completely embedding all of the lumped components into a common printed circuit board (PCB). |
| 3622 | Computer #51 |
Modified Class E Amplifiers Used For Two Channel Digital RF Transmit Array System With Integrated Coil |
1Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey, 2National Magnetic Resoncance Reasearch Center UMRAM, Bilkent University, Ankara, Turkey |
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In this work we show a two-channel digitally controlled on coil high efficiency modified Class E amplifier for RF excitation easily tunable for 1.5 and 3 T. The amplifiers coupling in dual channel outside the scanner was investigated to show how the operation integrity of nearby amplifiers is affected. MR experiment in a 3 T scanner was conducted in order to test the two-channel system and showed the feasibility of the system for larger number of channels. |
| 3623 | Computer #52 |
Gradient Amplifier Design with Advanced Power Semiconductor Devices and Simple Topology |
1GE global research center, Niskayuna, NY, United States |
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Gradient Amplifier is one of the key components in a MRI system to supply the gradient coil with large current (>1000A) and high voltage (>2000V) to achieve strong gradient field and fast slew rate. In this paper, a high efficiency two H-bridge in cascaded gradient driver design with 1700V SiC MOSFET is designed and fabricated. The power module switching frequency is 31.25 kHz and amplifier total output ripple frequency is 125 kHz. The amplifier loss and efficiency (around 99.5%) is verified in experimental results. |
| 3624 | Computer #53 |
A High Power RF Gated Wireless Power Transfer System |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Procyon Engineering, San Jose, CA, United States, 3Radiology, Stanford University, Stanford, CA, United States |
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If wireless patient coils could be realized, they would reduce setup time and reduce worry about the liability of the connectors on coils. Battery powering these coils would limit scan time, so it is desirable to use wireless power transfer (WPT), which uses inductively coupled resonant coils to transmit and receive power at a particular frequency. With RF gating, imaging while receiving up to 11W is demonstrated and shown to have minimal impact on image quality. |
| 3625 | Computer #54 |
gr-MRI: GNU Radio extensions for MRI using software-defined radios |
1Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 2Vanderbilt University Institute of Imaging Science, Nashville, TN, United States |
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Software defined radios have been shown to be a highly configurable, low cost alternative to traditional MRI spectrometers. They are well supported by the open-source GNU Radio software, however there are currently no GNURadio extensions to enable their use for MRI. In this work we describe a library of GNU Radio extensions for MRI, which implements all of the basic capabilities of an MR spectrometer in an SDR. The software will enable users to develop custom, low-cost MR spectrometer systems without requiring custom hardware design. We demonstrate its use via its built-in spin echo, gradient echo, and inversion recovery sequences. |
| 3626 | Computer #55 |
Magnetic field stability and homogeneity of high-temperature superconducting magnet with REBCO tapes measured using dedicated field camera system |
1Kyoto University, Kyoto, Japan, 2Toshiba corporation, Tokyo, Japan, 3Hokkaido University, Sapporo, Japan, 4Osaka University, Osaka, Japan, 5Waseda University, Tokyo, Japan |
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Because of the rapid rise of helium price in recent years, we started a project targeting to produce high-temperature superconducting ultra-high-field MRI systems with REBCO (Rare-earth - Barium - Copper Oxide) tapes and as the first step, we developed a middle-size 1T-REBCO magnet and evaluated its magnetic field stability and homogeneity with dedicated field camera system with 16ch NMR probes. Inhomogeneity was up to 800 ppm and stability with linear trend correction was ±1 ppm, and the causes were investigated. |
| 3627 | Computer #56 |
The Study of Quench Propagation for a MgB2 1.5 T MRI Magnet Design at Different Operating Temperatures |
1Department of Physics, Case Western Reserve University, Cleveland, OH, United States, 2Hyper Tech Research Inc., Columbus, OH, United States |
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To reduce the usage of liquid helium, conduction cooled MRI magnets using high temperature magnesium diboride (MgB2) have been considered. Because the thermal normal zone propagation velocity (NZPV) of MgB2 is much slower compared to NbTi wire, active quench protection is needed. The temperature rise in the magnet design was modeled using Douglas-Gunn method to solve the governing heat equation for operating temperatures ranging from 10 to 18 K. It was shown that the temperature rise is slower for higher operating temperatures, and thus better for quench protection. |
| 3628 | Computer #57 |
Very-high order shimming in the human spinal cord using a dedicated 24-channel array coil |
1NeuroPoly Lab, Institute of Biomedical Engineering, École Polytechnique de Montréal, Montreal, QC, Canada, 2Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 3Resonance Research Inc., Billerica, MA, United States, 4Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 5Siemens Healthcare Ltd., Montreal, QC, Canada, 6Montreal Heart Institute, Université de Montréal, Montreal, QC, Canada, 7Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada |
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Pathologies of the spinal cord are a primary cause of functional disability and chronic pain. Although MRI already plays a role in the evaluation of these pathologies, it continues to be hampered by artifacts due to magnetic field inhomogeneity. This study reports the first results applying a specially designed 24-channel shim array to correct magnetic field inhomogeneity in the human spinal cord. Shimming using the custom array improved field homogeneity in the thoracic spinal cord of the two initial subjects by 53.6 % and 31.4 % respectively. |
| 3629 | Computer #58 |
Dedicated High-Performance, Lightweight, Low-Cryogen Compact 3.0T MRI System for Advanced Brain Imaging |
1GE Global Research, Niskayuna, NY, NY, United States, 2Mayo Clinic, Rochester, MN, United States |
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A high-performance, lightweight, low-cryogen compact 3.0T MRI system for imaging the brain has been developed. This system has a gradient performance of 80 mT/m and 700 T/m/s, and has a magnet weight of less than 2,000 kg and has a 5 Gauss fringe field area of 24 m2. This novel system has produced images that are equivalent if not better than that encountered in whole-body 3.0T scanners. This was demonstrated in imaging tests in healthy volunteers. Clinical evaluation is scheduled for a patient population. |
| 3630 | Computer #59 |
A design of a mobile, homogeneous and efficient electromagnet with a large field-of-view for neonatal low field MRI |
1Research Center Magnetic-Resonance-Bavaria (MRB), Wuerzburg, Germany, 2Center of Neural Engineering, Departments of Engineering Science and Mechanics, Neurosurgery, and Physics, Penn State University, University Park, PA, United States, 3High Field MRI Facility, Huck Institutes of the Life Sciences, Penn State University, University Park, PA, United States, 4Department for Experimental Physics 5 (Biophysics), University of Wuerzburg, Wuerzburg, Germany |
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A mobile and effective electromagnet prototype with a large field-of-view for neonatal magnetic resonance imaging at 23 mT is presented. The efficient implementation succeeded by exploiting the use of steel plates as a housing system. This results in a design that ensures an optimum between large sample volumes, high homogeneity, high B0 field, low power consumption, light weight, without the necessity of a dedicated water cooling system. Simulations and measurements are shown, which illustrate the functionality and quality of this imaging system. There are multiple paths to clinical and medical applications for such low cost devices. |
| 3631 | Computer #60 |
RF coil configurations for a RF-penetrable PET insert for simultaneous PET/MR |
1Mechanical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States, 3Bioengineering, Stanford University, Stanford, CA, United States, 4Applied Physics, Stanford University, Stanford, CA, United States, 5Physics, Stanford University, Stanford, CA, United States, 6Electrical Engineering, Stanford University, Stanford, CA, United States |
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Simultaneous acquisition of MRI and PET shows great promise for disease characterization as it enables concurrent collection of complementary molecular and anatomical information. To overcome the limited dissemination of integrated PET/MRI systems due to the high cost, we have developed an RF-penetrable PET insert integrated with custom RF coils that can be inserted into any existing MRI system for simultaneous PET/MRI acquisition. The RF-penetrable PET/RF-receiver insert enables the use of the built-in body coil for more uniform transmit RF field, fast acquisition using parallel imaging, and high SNR MR and PET images. |
| 3632 | Computer #61 |
A low cost home-built gradient amplifier for matrix gradient coils |
1Dept. of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2Dept. of Clinical Neurology and Neurophysiology, University of Freiburg, Freiburg, Germany |
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To address the increased cost of high numbers of amplifiers for matrix gradient coils, a low cost home-built 100A/100V gradient amplifier is proposed. The water cooling amplifier consists of several parts: a controller that interfaces to a waveform generator and provides the current control signal; an H-bridge circuit that generates constant current to the load; and a ripple cancellation filter that reduces the inevitable ripple current. The switching frequency and peak ripple current of amplifier is 100 kHz and 300 mA, respectively. The amplifier can be operated with maximum continuous current (100A) for at least 1 min. |
| 3633 | Computer #62 |
Low-Field Permanent Magnet MR Systems in the Developing World: A Review of Clinical and Research Applications |
1Radiology, Northwestern University, Chicago, IL, United States, 2Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, United States, 3Department of Radiology, University of Ibadan, Ibadan, Nigeria, 4Department of Radiology, University of Chicago, Chicago, IL, United States |
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Low-field permanent magnet MR systems will be increasingly utilized in resource-limited settings due to their independence from helium and power supply infrastructure. Optimization of available systems for clinical imaging will greatly improve diagnostics and lead to unique opportunities to study health concerns in developing countries. This exhibit summarizes the state-of-the art in permanent magnet MRI to encourage interest in the improvement of existing systems and their utilization for collaborative imaging research in the developing world. |
| 3634 | Computer #63 |
A simple digital MRI system using a digital oscilloscope |
1University of Tsukuba, Tsukuba, Japan |
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A digital MRI system was developed using a digital oscilloscope that had a waveform generator function. An RF pulse with 43.85 MHz Larmor frequency was successfully output using this oscilloscope and the NMR signal was captured using the undersampling technique (144 ns dwell time, 6.94 MHz sampling frequency). The acquired a set of 3D MR image using a 1.0 T permanent magnet MRI system demonstrated the validity of our approach. |
| 3635 | Computer #64 |
An Active Quench Protection System for a 1.5 T MgB2 Conduction-Cooled Magnet |
1Department of Physics, Case Western Reserve University, Cleveland, OH, United States, 2Hyper Tech Research Inc., Columbus, OH, United States |
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A numerical simulation of the heat equation was performed for a 10 coil persistent mode 1.5 T MgB2 conduction-cooled magnet. A hot spot was initialized by allowing a section of wire to become resistive on one coil. An active protection system consisting of surface heaters on all the coils was initiated at 100 mV. Using a standard wire, the temperature was found to reach nearly 300 K, which may damage the coil. By increasing the amount of copper, using Glidcop instead of Monel, or increasing the thermal conductivity of the insulation, the temperature is kept within safe limits. |
| 3636 | Computer #65 |
DETECTION OF MR SIGNAL DURING RF EXCITATION USING FULL DUPLEX RADIO SYSTEM |
1Electrical and Electronics Engineering Department, Bilkent University, Ankara, Turkey, 2National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey, 3Department of Radiology - Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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In this work, we demonstrated feasibility of MRI with concurrent excitation and acquisition (CEA) using our decoupling method which is potentially useful for MRI of tissues with ultra-short T2*. We have used the concepts used in the full-duplex radio system to suppress the Tx signal coupled on the Rx coil. We could achieve up to 100 dB decoupling between Tx and Rx coils using the cancellation circuit. 3D pulse radial scan was conducted using CEA. Deconvolved MR signal response from a rubber phantom and image of it in coronal slice orientation is demonstrated as the feasibility of the proposed method. |
| 3637 | Computer #66 |
Evaluation and Integration of a Dual-Tuned 13C/1H Headcoil into PET/MR Hybrid Imaging |
1High Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany, 2Rapid Biomedical GmbH, Rimpar, Germany, 3Erwin L. Hahn Institute for MR Imaging, University Duisburg-Essen, Essen, Germany |
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A dual tuned 13C/1H radiofrequency head coil was evaluated towards its potential use in integrated PET/MR hybrid imaging. The amount of PET-signal attenuation due to the head coil was quantified in phantom experiments. A CT-based 3D template µ-map of the hardware components was generated and evaluated for attenuation correction (AC). The head coil homogeneously attenuates the PET signal by 10%. Attenuation correction homogeneously reduced this attenuation bias to below 1%. These results were confirmed in PET/MR measurements of six patients. The RF head coil was successfully integrated into PET/MR hybrid imaging and can now be used for multinucleus hybrid imaging. |
| 3638 | Computer #67 |
Open Source Imaging Initiative |
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine, Berlin, Germany, 2Department of Physics, Technische Universität Berlin, Berlin, Germany, 3Physikalisch Technische Bundesanstalt (PTB), Berlin, Germany, 4Berlin Center for Advanced Neuroimaging, Charité - Universitätsmedizin, Berlin, Germany, 5Department of Radiology, Stanford University, Stanford, CA, United States, 6Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, United States, 7Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Netherlands, 8Institute of Physics, University of Mainz, Mainz, Germany, 9Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine, Berlin, Germany, 10MRI.TOOLS GmbH, Berlin, Germany |
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Regardless public or private healthcare system, MR costs determine healthcare outcomes. There is a high demand for affordable MR technology around the world to improve patient diagnosis and treatment. The aim of the open source imaging initiative (www.opensourceimaging.org) is to collaboratively build an affordable MR scanner and make its technical documentation available according to the standards of open source hardware. Combining innovation and open source allows major reduction of investment and operational costs with the ideal: From the community to the community. |
| 3639 | Computer #68 |
Decoupling Scheme for a Cryogenic Rx-Only RF Coil for 13C Imaging at 3T |
1Department of Electrical Engineering, Technical University of Denmark, Kgs Lyngby, Denmark, 2MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark, 3Danish Diabetes Academy, Odense, Denmark |
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In this study we evaluate the different active decoupling schemes that can be used to drive an Rx-only coil, in order to determine the optimal design for 13C MRI at 3T. Three different circuit schemes are studied: two known ones (with regular series and parallel tuning respectively), and a novel one which we found to be optimal for this case. The circuits have been cooled to 77K to reduce coil noise. Preliminary tests with the preamplifier cooled to 77K for reduction of noise figure, are also reported. |
| 3640 | Computer #69 |
Development of Rotary Magnet MRI for Free Radical Imaging |
1Innovation Center for Medical Redox Navigation, Kyushu university, Fukuoka, Japan, 2FUJI ELECTRIC CO., LTD., Tokyo, Japan, 3NOEMAX ENGENEERING Co., LTD, Gunma, Japan, 4MEIKO Co., LTD., Yamanashi, Japan, 5Japan Redox Limited, Fukuoka, Japan |
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poster file |
| 3641 | Computer #70 |
A hybrid RF shielding for PET inserts using carbon fiber and slotted copper layers |
1Institute for Instrumentation in Molecular Imaging, i3M, Valencia, Spain, 2Preclinical Imaging, Bruker BioSpin, Ettlingen, Germany, 3Institute of Design and Manufacture, Valencia, Spain |
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A novel approach for radio-frequency shielding using hybrid carbon fiber materials and slotted copper layers. A proof of concept has been built and tested in high frecuency MR scanners. The purpose is to use it to shield the MR RF field on PET electronics, allowing simultaneous PET-MR acquisitions. |
| 3642 | Computer #71 |
Optimization of DWI sequences using a dynamic consumption energy simulation model for large bore Actively Shielded Gradient Coil |
1MRI development department, Toshiba Medical Systems corp., Otawara, Tochigi, Japan |
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Estimating the accurate consumption energy of gradient power supply and gradient coil leads to advantage on an optimized power supply for environment and to achieve an economical system. In addition, providing sufficient power supply permits a flexibility in pulse sequences. The gradient power energy consumption depends on the gradient waveform. Because the gradient coil resistance is affected by frequency of gradient waveform, a simulation model is proposed to estimate the dynamic consumption energy with equivalent circuit for the gradient coil and evaluated actual and simulated consumption energy of DWI imaging with various conditions to ensure accuracy of the model. |
| 3643 | Computer #72 |
Accuracy and long-term stability measurements of a motion estimation sequence for hybrid PET-MR systems |
1GE Healthcare, Zurich, Switzerland, 2GE Healthcare, Stanford, CA, United States, 3GE Healthcare, Rochester, MN, United States, 4GE Healthcare, Waukesha, WI, United States |
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One of the known potential benefits of integrated positron emission and magnetic resonance (PET/MR) scanners is the possibility of using MR data to monitor patient motion. The present work evaluates the performance of a new pulse sequence designed exclusively for PET/MR head tracking. By assuming that all the required imaging data is provided by the PET subsystem, the MR sequence can be optimized exclusively for the task of providing accurate motion estimates over long periods of time (e.g. 30-60min). Data management, SAR and noise concerns are therefore minimized. |
| Exhibition Hall | Tuesday, May 10, 2016: 17:00 - 18:00 |
| 3644 | Computer #73 |
DEVELOPMENT OF A SET OF GENERIC NUMERICAL BIRDCAGES FOR COMPREHENSIVE EVALUATIONS OF INDUCED RF FIELDS FOR IMPLANT SAFETY |
1IT'IS Foundation, Zurich, Switzerland, 2ETHZ, Zurich, Switzerland |
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A study of in vivo radiofrequency exposure of a group of human models to a reduced set of birdcages that cover clinical scanner variability was performed at 64 MHz, with a view to the assessment of implant safety during magnetic resonance imaging. Finite-difference time-domain simulations were run for combinations of human model/landmark/birdcage for quadrature fed coils representing closed-bore systems with respect to RF exposure. The evaluation of the E-fields for the Tier 3 of TS109741 shows large variations in the tangential E-field values obtained with the different coils. |
| 3645 | Computer #74 |
Uncertainty of RF Induced Heating Tests of a Generic Orthopedic Implant in Different Phantoms |
1MR:comp GmbH, Gelsenkirchen, Germany, 2Faculty of Engineering/ATE, Duisburg-Essen University, Duisburg, Germany, 3MRI-STaR GmbH, Gelsenkirchen, Germany |
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comparison study has been implemented for a generic orthopedic implant (GOI) in ASTM and Elliptical phantom as well as in homogeneous and heterogeneous Duke model in terms of RF induced heating to evaluate the uncertainty of RF induced heating tests in phantoms. The parameters to be evaluated to track the hotspots at the surrounding tissue of the GOI were assessed. |
| 3646 | Computer #75 |
Decoupling a prosthetic hip implant from a parallel transmit array using different numbers of transmit channels |
1Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 2Centre for the Developing Brain, King's College London, London, United Kingdom |
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Ensuring safe imaging around metallic implants is paramount to safety in MRI. Parallel transmission offers the possibility of electromagnetically decoupling metallic implants from an RF coil. Here the impact of the number of transmit channels used is assessed in terms of reduction of SAR around the implant and improvement in the homogeneity of the B1+ imaging field. |
| 3647 | Computer #76 |
The Effect of Field Strength on Wire-tip Heating: Simulation and Direct Measurements at 1.5T and 3T |
1Department of Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, 2Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, United States |
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MRI presents several potential risks for patients with implanted devices and one of the main concerns is RF induced heating of devices and nearby tissues. The aim of this study was to compare the RF induced heating characteristic of wires at 1.5T and 3T using simulations and direct measurements. Greater heating (SAR amplification) can be observed at lower field strengths for longer wires. |
| 3648 | Computer #77 |
Genetic damage investigations after repeated exposures to 7 T Magnetic Resonance Imaging |
1Biomedical Magnetic Resonance, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany, 2Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany, 3Department of Radiology, University of Texas Health Science Center, San Antonio, TX, United States, 4Department of Radiology and Nuclear Medicine, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany, 5Faculty of Natural Sciences, Brandenburg University of Technology Cottbus-Senftenberg, Senftenberg, Germany, 6Medipan GmbH, Dahlewitz/Berlin, Berlin, Germany, 7Leibniz Institute for Neurobiology, Magdeburg, Germany, 8Center for Behavioral Brain Sciences, Magdeburg, Germany, 9German Center for Neurodegenerative Disease, Magdeburg, Germany |
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Synopsis. Ultra-high field magnetic resonance imaging (UHF MRI) is a technological development which is now only used for research purpose. Healthy individuals working with UHF MRI scanners as well as those participating in research investigations are repeatedly exposed to high field strengths, which can be >2-fold greater than those regularly used in clinics. In this study, we have examined the extent of genetic damage in peripheral blood mononuclear cells (PBMC) obtained from such individuals exposed to 7T MRI. |
| 3649 | Computer #78 |
Large volume distributed temperature measurements using MRI-compatible Raman spectroscopy |
1Leiden University Medical Centre, Leiden, Netherlands, 2Technical University Delft, Delft, Netherlands |
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A new method of monitoring temperature non-invasively within an MRI scanner is introduced. This method is based on Raman backscattering, with the sensor consisting of a long length of thin optical fibre which can be arranged in any desired geometry. The major advantage over existing techniques is that a wide area of surface temperatures can be monitored simultaneously. Preliminary feasibility of the approach is shown here for localized and global temperature measurements. |
| 3650 | Computer #79 |
Accurate and precise dynamic contrast enhanced (DCE) measurements with reduced gadolinium toxicity by lengthening pre-injection baseline |
1Radiology, Loma Linda University Medical Center, Loma Linda, CA, United States, 2Radiology, Brigham and Women's Hospital, Boston, MA, United States, 3Caltech, Pasadena, CA, United States |
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For increased patient safety it is desirable to acquire dynamic contrast enhanced (DCE) MRI data with the lowest passable Gd contrast agent (CA) dose. However, a lower CA dose generally leads to smaller signal changes and lower quality studies. Through simulations we show that lower CA doses (up to 1/2 dose) can be compensated for by extending the pre-injection baseline acquisition time to maintain similar accuracy and precision of the fitted Ktrans values. |
| 3651 | Computer #80 |
Effect of Renal Function on T1 signal changes in deep brain nuclei |
1Radiology, Weill Cornell Medical Center, New York, NY, United States, 2Radiology, Qilu Hospital, Shandong University, Jinan, China, People's Republic of, 3Radiology, Columbia University, New York, NY, United States |
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Dialysis patients had 3 times the signal increase on unenhanced T1-weighted images compared to a control population with near normal renal function undergoing the identical number of GBCA administrations. Although any clinical consequence to GBCA administration would be expected to be magnified in dialysis patients, no clinical effect of receiving GBCA could be identified in the nephrologist/nursing notes recorded 3 times a week in the 30 days following GBCA administration. |
| 3652 | Computer #81 |
Safety and diagnostic efficacy of Dotarem® (gadoteric acid) for MR mammography: Diagnosis vs. cytological findings |
1Radiology, University Clinic of Cologne, Cologne, Germany |
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A non-interventional post-marketing surveillance study carried out between January 2012 and October 2013 on 1,537 patients in 15 centres showed that Dotarem® (Guerbet, Roissy, France) is an effective contrast agent for the identification of invasive ductal carcinomas. An MR mammography with the diagnosis of invasive ductal carcinoma was confirmed in 93.5% of all cases by means of a subsequent cytological examination. Overall, a diagnosis was able to be made in 99.2% of the cases. Adverse reactions occurred in 5 patients (0.3%). In 4 out of 5 of the patients the adverse events were not serious and in one patient the adverse events were serious. |
| 3653 | Computer #82 |
Influences of 3.0 Tesla MRI noise on neonates and young adults: a longitudinal study |
1Department of Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, China, People's Republic of |
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The temporary or permanent effects of strong noise from MRI devices on hearing functions, especially for different age populations (e.g. neonate and adult) remain unclear. Here we conduct a longitudinal study targeting 3T MRI to disclose such effects on hearing functions of young adults and neonates. Results indicate that due to immaturity of hearing nerve system, neonates show weaker sensitivity to acoustic noise than adults. The 3T MRI noise resulted in transient decrease of young adults’ hearing function (i.e. temporary threshold shift), whereas showed rarely effects on neonates. |
| 3654 | Computer #83 |
Robust Simulation of MRI Gradient Field-Induced Vibration of an Implantable Medical Device |
1MR:comp GmbH, Gelsenkirchen, Germany, 2Faculty of Engineering/ATE, Duisburg-Essen University, Duisburg, Germany, 3MRI-STaR GmbH, Gelsenkirchen, Germany |
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The interaction between the gradient induced eddy current and the static magnetic field in the MRI system generates force and torque to a conductive implant if the eddy current magnetic moment and static magnetic field are misaligned. A frequency-domain solver (F-solver) of full-wave simulator CST studio suite 2015 was employed as an initial step to calculate the surface current induced due to the gradient field-induced switching. |
| 3655 | Computer #84 |
Measuring Gradient-Induced Vibration of a Conductive Device using Laser Doppler Vibrometry at 3T |
1Physics and Astronomy, Western University, London, ON, Canada |
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In this project, a method to quantify the gradient-induced vibration of a medical device in an MR system using a laser Doppler vibrometer is presented. A copper annulus was suspended in a 3T scanner, at a position chosen to maximize the x-component of the x-gradient. The displacement of the device was measured at different gradient field strengths. Typical observations were understood, which should lead towards helping establish a test standard for gradient induced vibrations of implanted medical devices. |
| 3656 | Computer #85 |
Effects of breast tissue density, size, and positioning on SAR at 7T |
1Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States |
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It is common practice to perform full-wave electromagnetic modeling to characterize RF transmit coils and establish safety parameters limiting power and SAR to comply with guidelines for pre-clinical use with human volunteers. Currently-available female voxel models are unsuitable for simulating the filling factor of breast coils designed for women in the prone position. Accurate breast modeling is further confounded by variability of lipid and fibroglandular tissues, with modeling implications owing to disparate conductivity and permittivity values. This work presents simulations at 7T using high-resolution, anatomically-correct breast phantoms exhibiting varying proportions of fatty and fibroglandular tissues, as well as breast tissue girth, length, and positioning within the RF coil, demonstrating the effects of these variables in projected SAR for breast imaging. |
| 3657 | Computer #86 |
Potential Effects of MR-induced Temperature Increase on PET Signal during MR/PET: Simulations of a Worst-Case Scenario |
1Radiology, Center for Advanced Imaging Innovation and Research (CAI2R), New York, NY, United States, 2Radiology, Bernard and Irene Schwartz Center for Biomedical Imaging, New York, NY, United States |
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We explore the possibility that SAR-related temperature increase could affect metabolic rates enough to alter FDG signal in MR/PET. Using numerical simulations, we calculate the distributions of SAR, temperature, metabolic rates, FDG concentration ([FDG]), and PET signal throughout the human body. Calculation of [FDG] utilizes a two-compartment model considering metabolic rate through time. Results are calculated for injection time one hour before the onset of imaging and for injection time simultaneous with the onset of imaging. Even for worst-case scenario (max allowable whole-body SAR for the duration of the scan), there is little observable effect on PET signal. |
| 3658 | Computer #87 |
Local Q-matrix computation for parallel transmit MRI using optimal channel combinations |
1Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 2Centre for the Developing Brain, King's College London, London, United Kingdom |
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Computing 10g averaged local SAR Q-matrices for parallel transmission MRI using self-implemented code is complex and computationally expensive. Here we present a simple method for computing Q-matrices using channel combinations of 10g SAR calculated with electromagnetic field simulation software and then simply constructed into Q-matrices from these combinations. |
| 3659 | Computer #88 |
Heating Reduction in Unilateral And Bilateral Implanted Leads At 3T Using Parallel Radiofrequency Transmission in a Heterogeneous Head Model |
1University of Toronto, Toronto, ON, Canada, 2Massachusetts General Hospital, Charlestown, MA, United States, 3Sunnybrook Health Sciences Centre, Toronto, ON, Canada |
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Long implanted wires, such as deep brain stimulation (DBS) implants, are subject to radiofrequency (RF) heating during MRI. In previous work, RF shimming was used to tailor the electric and magnetic fields creating optimal excitation and minimal heating in a uniform cylindrical medium with a single, straight, implanted copper wire at 3T. This work extends the methodology to a complex, heterogeneous head model with one or two implanted, curved copper wire(s). A substantial improvement in both B1+-field homogeneity and E-field reduction is achieved when compared with a transmit/receive birdcage coil in both the single wire and bilateral wire case. |
| 3660 | Computer #89 |
Database Construction for Local SAR Prediction: Preliminary Assessment of the Intra and Inter Subject SAR Variability in Pelvic Region |
1Center for Image Sciences, University Medical Center Utrecht, Utrecht, Netherlands |
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A reliable technique to assess the 10g averaged Specific Absorption Rate is necessary for parallel transmit ultra-high field body MRI. We believe that the best solution is to build a database with many different models. We have created nine dedicated body models and performed FDTD simulations on them to evaluate the inter-subject variability for prostate imaging at 7T using fractionated dipole antennas. Maximum SAR10g ranges from 1.64 to 2.48W/kg with 8x1W input power. No relationship was found between BMI and maximum SAR10g. Intra-subject variability (caused by slight antenna positioning variability, +/-2cm) was also investigated showing up to 67.8% SAR variability. |
| 3661 | Computer #90 |
Synthesis and SAR Assessment of Multi-slice PINS SLR RF Pulses for Wideband MRI: A Simulation Study |
1Interdisciplinary MRI/MRS Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan |
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The multislice RF pulse excitation is required in some simultaneous multi-slice (SMS) methods. The aim of this study was to investigate the synthesis method and SAR (Specific Absorption Rate) of multislice PINS (Power Independent of Number of Slices) SLR RF pulses for Wideband MRI and other SMS methods. The relative values of SAR of the standard SLR and PINS SLR RF pulses with different number of slices W are presented. It can be found that the values of SAR of PINS SLR pulses were greatly reduced compared to that of the standard SLR pulses. For example, The SAR of PINS SLR with W = 5 is only 38% of that of standard SLR with W = 5. And The SAR of PINS SLR with W = 5 is only 1.9 times of that of standard SLR with W = 1. |
| 3662 | Computer #91 |
A Multi-Channel Real-Time Power Monitoring System for SAR Estimation Using FPGA in High Field MRI |
1State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, People's Republic of, 2Key Laboratory of Nuclear Radiation and Nuclear Energy Technology, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China, People's Republic of, 3State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China, People's Republic of |
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Specific absorption rate (SAR) is a limiting factor for high field MRI due to excess RF power deposition in human subjects. In this study, we developed a multi-channel real-time RF power monitoring system for global and local SAR estimation using FPGA to ensure patient safety. The major components of the monitoring system include multiple dual directional couplers, demodulating logarithmic power sensors, analog to digital converters and a FPGA fast signal processing unit, etc. The deviation of the power measurement was less than 0.5dB after calibration for system errors over a dynamic RF signal range of 100dB. |
| 3663 | Computer #92 |
Local SAR increase in the human head induced by high-permittivity pads at the sodium (23Na) resonance frequency at 7 Tesla |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany |
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It has been shown that specific configurations of high-permittivity pads can lead to an increase of local SAR. So far, the effects of high-permittivity pads on RF fields have been investigated only for 1H imaging at 7 Tesla. For X-nuclei imaging typically dual-tuned coils are applied. In this work, we investigate the effect of high-permittivity pads, typically utilized to optimize RF fields for 1H imaging, for 23Na imaging at 7T. RF simulations were performed for two body models to determine under which conditions SAR elevations are likely to occur or can be avoided. |
| 3664 | Computer #93 |
RF Heating Studies on Anesthetized Pigs by Using Fractionated Dipole Antennas at 7T |
1CMRR,Radiology, University of Minnesota, Minneapolis, MN, United States, 2Medical Image Analysis and Biometry Laboratory, Universidad Rey Juan Carlos, Mostoles, Madrid, Spain, Madrid, Spain, 3Madrid-MIT M+Vision Consortium in RLE, Massachusetts Institute of Technology, Boston, MA, United States, 4Boston Children's Hospital, Harvard Medical School, Boston, MA, United States |
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We present our results regarding electromagnetic & thermal simulations as well as temperature measurement studies in anesthesized pigs. Pig models were generated by segmenting tissues from CT images. Fractionated dipole antennas were used to deliver RF energy in the pigs body. Power levels used for RF excitation were monitored. Temperature measurements were made using 4 fiber optic probes at locations which are visible in the digital pig model. Simulation and Experiment results were compared. |
| 3665 | Computer #94 |
E-field Comparison of 1.5T Transmit Head and Extremity Coils to 1.5T Body Coils – Implications for Implantable Cardiac Pacemaker and Defibrillator RF Heating and Unintended Stimulation |
1St. Jude Medical, Sunnyvale, CA, United States, 2University of Houston, Houston, TX, United States, 3St. Jude Medical, Sylmar, CA, United States |
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E-fields tangential to implantable cardiac pacemakers and defibrillators were analyzed at Normal and First Level Controlled Operating Modes as well as 30uT peak B1+. 1.5T body transmit and head and extremity transmit RF coils were simulated. A comparison of the Etans generated by the body transmit coils is made to those generated by head and extremity transmit coils. If RF heating and voltage can be shown to be safe with unrestricted body coils then no additional analysis is necessary for head and extremity coils since there is a 9x margin in RF heating and 3x margin in voltage. |
| 3666 | Computer #95 |
RF safety assessment of a 7 Tesla breast coil: SAR versus tissue temperature limits |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany |
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RF safety of Tx coils can be assessed based on SAR or temperature limits; however, temperature is directly correlated to tissue damage and enables a more precise RF exposure assessment. Both safety assessments were compared for a 7T breast coil. Temperature depends on the individual thermoregulation system and was taken into account using three different temperature-dependent blood perfusions. Results for a subject with impaired thermoregulation showed that temperature limits are exceeded by up to 6.17 °C even when SAR limits are complied with. For a healthy subject, up to 40% higher input power is allowed if temperature limits are applied instead of SAR. |
| 3667 | Computer #96 |
Globally Applicable MR Safety Course for Medical Students |
1Department of Radiology, University of Chicago Medical Center, Chicago, IL, United States, 2Department of Radiology, Northwestern University, Chicago, IL, United States, 3Department of Medical Imaging, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL, United States |
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We propose an educational magnetic resonance (MR) safety course for instructing medical students world-wide about basic MR and patient-related safety. The MR safety course material can be implemented as a traditional didactic or interactive lecture in combination with hands-on safety demonstrations and will prepare medical students for patient screening and safety consultations when ordering MR studies. This course can be implemented globally by various medical school programs to ensure consistent quality of teaching materials and MR safety standards. |
| Exhibition Hall | Wednesday, May 11, 2016: 10:00 - 11:00 |
| 3668 | Computer #1 |
Measuring Perfusion with a Hyperpolarised Ultra-Long T1 15N Glutamine Compound |
1GE Global Research, Munich, Germany, 2Technische Universität München, Munich, Germany, 3Università di Torino, Turin, Italy |
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An experimental setup for 15N was established on a clinical 3T whole-body scanner, in order to measure perfusion with an ultra-long T1 15N compound. The substance α-trideuteromethyl[15N]glutamine was synthesised, polarised and injected into healthy rats to study the perfusion of the kidneys. With a T1 time in vivo of 146s, it was possible to acquire perfusion images for over 5 minutes. |
| 3669 | Computer #2 |
In vivo 3D mapping of intracellular pH using hyperpolarized [1-13C]pyruvate in the rodent heart |
1Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom, 2Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, United Kingdom, 3Department of Physics, Clarendon Laboratory, Oxford, United Kingdom |
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Intracellular pH can be measured in vivo by taking the ratio between hyperpolarized HCO3- and CO2 produced from [1-13C]pyruvate, but to date, low CO2 signal has limited this method to whole-heart assessment. We propose a 3D imaging approach using spectrally-selective excitation which exploits the rapid exchange between HCO3- and CO2 to produce in vivo myocardial pHi maps. The intracellular pHi is found to be 7.15±0.04 in the healthy rodent heart. Increased cardiac workload via continuous dobutamine infusion resulted in a decreased intracellular pH of 6.90±0.06. |
| 3670 | Computer #3 |
Branched-chain α-keto acid decarboxylation and transamination assessment in mouse liver and kidney using hyperpolarized α-keto[1-13C]isocaproate MRS |
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States |
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The branched-chain α-keto acid dehydrogenase (BCKDH) is an important regulator of branched chain amino acid (BCAA) catabolism. In several diseases including liver cirrhosis, decreased BCKDH activation results in increased BCAA breakdown through the branched-chain amino transferase (BCAT) and subsequent protein and energy deficiency. We show that both hyperpolarized Leucine and HCO3- signals can be detected in liver in vivo at 14.1 T as byproducts of [1-13C]KIC metabolism. This provided information on BCAT/BCKDH activities in mouse liver and kidney, consistent with literature values. Assessing the effect of BCAA supplementation on liver cirrhosis has the potential to impact patient monitoring and treatment. |
| 3671 | Computer #4 |
Hyperpolarized Carbon-13 Ketoisocaproate Reveals Dysfunction in Branched-Chain Amino Acid Metabolism in Liver Cancer |
1FUNCTIONAL METABOLISM GROUP, SINGAPORE BIOIMAGING CONSORTIUM, Singapore, Singapore |
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Complex reprogramming of cellular metabolism to support tumorigenesis & survival is a hallmark of cancer. Recently Ericksen et al observed that the suppression of branched-chain amino acids (BCAA) catabolic enzymes is a unique signature in human hepatocellular carcinomas (HCC), and the degree of downregulation correlates strongly with tumor grades and survival outcomes1. Specifically the metabolic activity of the branched-chain keto-acid dehydrogenase (BCKDH) complex was significantly reduced. We hypothesize that this modulation can be measured in vivo by tracking the metabolism of hyperpolarized carbon-13 ketoisocaproate. |
| 3672 | Computer #5 |
Noninvasive in vivo assessment of cytosolic redox-state in rat liver using hyperpolarized [1-13C]alanine |
1Radiology, Stanford University, Stanford, CA, United States, 2Applied Sciences Laboratory, GE Healthcare, Menlo Park, CA, United States |
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Intracellular [lactate]:[pyruvate] is an important biomarker of cytosolic redox-state, directly reflecting free cytosolic [NADH]:[NAD+]. Hyperpolarized [1-13C]alanine, which can be also transported across the plasma membrane, is useful to measure relative concentrations of intracellular pyruvate and lactate. In this work, we propose a simple method to assess in vivo cytosolic redox-state using hyperpolarized [1-13C]alanine, and demonstrate the ethanol-induced redox change in rat liver. |
| 3673 | Computer #6 |
In-vivo Assessment of Lung Injury Using Hyperpolarized Carbon-13 MRI in a Two-hit Model of Acid Aspiration and VILI |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, United States, 3Anesthesiology and Critical Care, University of Pennsylvania, Perlman School of Medicine, Philadelphia, PA, United States, 4Bioengineering, University of Pennsylvania, Philadelphia, PA, United States |
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Ventilator induced lung injury (VILI) results from mechanical trauma and secondary inflammatory responses. Previous imaging studies focused on the effects of ventilator settings on structural or functional changes; however, no MRI studies have been conducted to elucidate the metabolic changes during VILI. In this study, the potential of HP [1-13C]-pyruvate and its conversion to [1-13C]-lactate as a marker for the lung inflammation was investigated in a two-hit model of acid aspiration and VILI. |
| 3674 | Computer #7 |
Zymonic acid - a novel 13C enriched biosensor for in vivo pH-imaging |
1Department of Nuclear Medicine, Klinikum rechts der Isar, München, Germany, 2Department of Chemistry, Technische Universität München, München, Germany, 3Department of Chemistry, Technische Universität München, Garching, Germany, 4Department of Medical Engineering, Technische Universität München, Garching, Germany |
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[1,5-13C2] Zymonic acid is derived from carbon 13 labelled pyruvic acid and can be easily deuterium enriched for spin lattice relaxation time prolongation. The molecule exhibits pH dependent NMR shifts and can be used for pH in vivo mapping. Phantom measurements on human blood on a 7T preclinical MRI system indicate that [1,5-13C2] ZA is a suitable pH sensor for pre-clinical and potentially also for clinical applications. |
| 3675 | Computer #8 |
pH Dependent Kinetics of the Decarboxylation of Pyruvate for pH Mapping Experiments |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States |
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We have shown that the kinetic rate of the production of bicarbonate from pyruvate is heavily pH dependent. An increase in the rate by a factor of ~10 can be achieved by maintaining the pH of the reaction always above 10.3, the pKa of bicarbonate. This discovery will allow researchers to quickly produce hyperpolarized bicarbonate to be used for in vivo pH mapping experiments. |
| 3676 | Computer #9 |
In Vivo Hyperpolarized 13C Diffusion Weighted MRI Measures Lactate Efflux and Changes in MCT4 Expression in Prostate Cancer |
1Radiology & Biomedical Imaging, University of California - San Francisco, San Francisco, CA, United States |
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Dissolution DNP provides a 10,000-fold signal enhancement to carbon-13 nuclei and enables real-time metabolic imaging. In addition to the Warburg Effect, many malignant cancers overexpress MCT4, the monocarboxylate transporter responsible for lactate efflux and extracellular acidification. Because of microenvironmental differences, diffusion weighted imaging (DWI) with hyperpolarized substrates may provide unique information on lactate efflux and MCT4 expression. Here we show that DWI with hyperpolarized substrates is sensitive to changes in MCT4 expression, as lactate ADC is increased by >40% in late-stage TRAMP tumors. This technique may potentially provide a novel way to assess metabolite compartmentalization and transporter expression in malignant disease. |
| 3677 | Computer #10 |
Early diabetic kidney maintains the cortico-medullary urea and sodium gradient |
1MR Research Centre, Aarhus University, Aarhus N, Denmark, 2Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden |
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To investigate the essential intrarenal electrolyte gradients in early diabetic kidneys, hyperpolarized 13C urea was applied to measure urea and sodium gradients. No differences in either intrarenal urea or sodium gradients were observed in early diabetes compared to healthy controls. These results indicate that the early metabolic and hypertrophic changes occurring in the diabetic kidney prelude the later functional alterations in diabetic kidney function, thus driving the increased metabolic demand commonly occurring in the diabetic kidney. |
| 3678 | Computer #11 |
Accelerating hyperpolarized metabolic imaging of the rat heart using k-t PCA and k-t SPARSE |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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Hyperpolarized metabolic imaging of the heart suffers from limited spatial specificity in current protocols. In this work two algorithms, k-t PCA and k-t SPARSE, that allow accelerated metabolic imaging are compared in simulations and used to acquire in-vivo metabolic maps in rats at one millimeter in-plane resolution. |
| 3679 | Computer #12 |
Sampling Hyperpolarized Substrates using a 1 Tesla Permanent Magnet. |
1Radiology, MSKCC, New York, NY, United States |
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Hyperpolarized MRI quantifies metabolic fluxes non-invasively. One limitation is the rapid loss of polarized signal, decaying according to its longitudinal relaxation (T1) time. We propose the use of a permanent, 1 Tesla spectrometer to lengthen T1s. We show longer T1 values across different functional groups. Scalar couplings were also visible and these advantages were translatable to biologically-relevant settings using perfused bioreactors. As more clinical trials are performed, it is essential to understand the behavior of HP molecules at field strengths similar to hospital magnets. Sampling HP substrates using permanent magnets is simple and cost-effective and will directly benefit clinical imaging. |
| 3680 | Computer #13 |
Hyperpolarized 13C-labeled 5-5-dimethyl-1-pyrroline-N-oxide for in vivo detection of reactive oxygen species |
1Radiation Biology Branch, National Cancer Institute, Bethesda, MD, United States, 2Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan, 3Imaging Probe Development Center, National Heart, Lung, and Blood Institute, Rockville, MD, United States, 4National Institute of Neurological Disorder and Stroke, Bethesda, MD, United States, 5Molecular Imaging Program, National Cancer Institute, Bethesda, MD, United States |
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5,5-Dimethyl-1-pyrroline-N-oxide (DMPO) is a spin trap agent used to detect reactive oxygen species (ROS). We synthesized 13C-labeled DMPO, and investigated feasibility of hyperpolarized 13C-DMPO to detect ROS generated in living animals. Hyperpolarized 13C-DMPO gave us a single peak at 76 ppm on the 13C-spectrum, and 13C-DMPO was distributed through the mouse body immediately after intravenous injection. The results indicate hyperpolarized 13C-DMPO provided sufficient magnitude of the 13C signal to be detected in the mouse body, and can be applied to some disease models to evaluate the capability for detection of ROS in vivo. |
| 3681 | Computer #14 |
Time-course metabolic changes in high-fat diet-induced obesity in rats: hyperpolarized 13C MRS |
1Department of Radiology, Chonnam National University Medical School, Gwang-ju, Korea, Republic of, 2Research Institute of Medical Imaging, Chonnam National University Medical School, Gwang-ju, Korea, Republic of, 3Department of Electronics and Information Engineering, Korea University, Gwang-ju, Korea, Republic of, 4Department of Anatomy, Chonnam National University Medical School, Gwang-ju, Korea, Republic of |
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Non-alcoholic fatty liver is an increasing common liver disease in world population. Recent hyperpolarized 13C magnetic resonance spectroscopy (HP 13C MRS) studies revealed the cellular metabolite changes associated with the various liver diseases in animals. However, a study for high-fat diet(HFD)-induced obesity using HP 13C MRS in animal model has not yet been performed until now. The purpose of this study was to investigate the time-course metabolic changes based on HP 13C MRS in HFD-induced obesity in rats and their correlations with serum enzyme levels. |
| 3682 | Computer #15 |
Noninvasive biomarkers for the diagnosis of hepatic ischemia reperfusion injury: A real-time in vivo hyperpolarized 13C MRS and IVIM-DWI |
1Research Institute for Medical Imaging, Chonnam National University Hospital, Gwangju, Korea, Republic of, 2Radiology, Chonnam Natioanl University Medical School, Gwangju, Korea, Republic of, 3Anatomy, Chonnam Natioanl University Medical School, Gwangju, Korea, Republic of |
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Hepatic ischemia reperfusion injury (IRI) induces cellular damage and causes cell death. It can lead to acute liver failure accompanied with biochemical changes, microcirculatory disturbances and/or histopathologic changes. Early detection of impaired liver function is vital for effective therapeutic interventions and thus prevents its progression to liver failure. However, an in vivo study of hepatic IRI model in combination with hyperpolarized 13C magnetic resonance spectroscopy (13C MRS) and diffusion-weighted imaging (DWI) has not yet been attempted until now. The purpose of this study was to investigate the cellular metabolite change, diffusion of water molecules and microcirculation of blood in rat model with hepatic IRI and their correlations with enzyme levels. |
| 3683 | Computer #16 |
Multi-modal and multi-scale measurement of metabolism in breast cancer cells both in vitro and in vivo |
1Medical Physics, University of Wisconsin at Madison, Madison, WI, United States, 2Morgridge Institute for Research, Madison, WI, United States, 3Laboratory for Optical and Computational Instrumentation, University of Wisconsin at Madison, Madison, WI, United States, 4Cell and Regenerative Biology, University of Wisconsin at Madison, Madison, WI, United States, 5UW Carbone Cancer Center, Madison, WI, United States, 6Mechanical Engineering, University of Wisconsin at Madison, Madison, WI, United States, 7Biomedical Engineering, University of Wisconsin at Madison, Madison, WI, United States, 8Radiology, University of Wisconsin at Madison, Madison, WI, United States |
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A system and workflow for spatially registered in vivo optical microscopy, MRI, and PET of breast tumor metabolism is described. The system is coupled with a bioreactor designed to compare cellular metabolism in vitro using both optical microscopy and MR spectroscopy with the behavior of tumor cells in the in vivo tumor microenvironment. Results from enzyme reactions are shown, demonstrating the temperature control capabilities of the bioreactor. A proof of concept in vivo experiment is also described, with optical microscopy data of a mammary tumor acquired in conjunction with MRI and PET data, on the same animal. |
| 3684 | Computer #17 |
LED induced 19F-MR-signal enhancement at 7T |
1Department for Biometrics and Medical Informatics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany, 2Institute for Physical and Theoretical Chemistry, University of Bonn, Bonn, Germany |
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19F containing substrates serve as attractive reporter molecules for NMR and MRI studies. Applications for in vivo studies are limited by low spin densities due to restricted concentrations. Using hyperpolarization techniques, such as Chemically Induced Dynamic nuclear Polarization (CIDNP), this constrained can be overcome. So far, 19F hyperpolarization generated in D2O, which is a prerequisite for an in vivo application, could only be documented using laser photo-CIDNP. In this study the successful hyperpolarization of a 19F nucleus in in 3-fluoro-DL-tyrosine in its free and a complexed form using D2O as a solvent is presented using a simple LED photo-CIDNP device. |
| 3685 | Computer #18 |
A Method to Identify and Correct for Blurring Artifacts in Hyperpolarized Metabolic Imaging |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, United States |
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Hyperpolarized imaging sequences are subject to potential bias and spread of apparent signal to neighboring voxels due to the time-dependence of magnetization as RF pulses are applied and as polarization is lost through spin-lattice relaxation. In this abstract, we discuss a method to detect and correct for artifacts and demonstrate it using chemical shift imaging. The method utilizes periodic resampling of nonselective spectra to correct for signal dynamics. We show that this technique results in a higher fidelity, "de-blurred" image. |
| 3686 | Computer #19 |
Hyperpolarized 1-13C Pyruvate Imaging of Porcine Cardiac Metabolism shift by GIK Intervention |
1MR Research Centre, Aarhus University, Aarhus N, Denmark, 2Danish Diabetes Academy, Odense, Denmark, 3Cardiology, Aarhus University Hospital, Aarhus N, Denmark |
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Cardiac metabolism has gained considerable attention worldwide lately, both as a diagnostic and prognostication tool, as well as a novel target for treatment. As human trials involving hyperpolarized MR in the heart are imminent, we employed a clinically relevant, large animal model, and sought to evaluate the general feasibility to detect an imposed shift in metabolic substrate utilization during metabolic modulation with glucose, insulin and potassium (GIK) infusion. This study demonstrates that hyperpolarized 13C-pyruvate, in a large animal, is a feasible method for cardiac studies, and, in combination with GIK intervention; that it is able to detect imposed metabolic shifts. |
| 3687 | Computer #20 |
Para-Hydrogen Induced Polarization: Advances in Amino Acid Polarization and Hyperpolarization in Heterogeneous Phase |
1University of Southampton, Southampton, United Kingdom, 2University of California Los Angeles, Los Angeles, CA, United States, 3RWTH Aachen University, Aachen, Germany, 4Cedars Sinai Medical Center, Los Angeles, CA, United States |
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We present new amino acid derivatives that can be hyperpolarized with the Para-Hydrogen Induced Polarization method (PHIP). Furthermore, we report on the highest achieved polarization of amino acid derivatives in biocompatible medium (water) to date with relevance for in vivo applications. Moreover, the first heterogeneous catalyst for PHIP in water will be presented that leads to significant levels of polarization. This poses the possiblity of a quick filtration step to yield clean PHIP-polarized contrast agents for future in vivo studies. |
| 3688 | Computer #21 |
First hyperpolarization of quaternary pyridinium salts using PHIP |
1Department for Biometrics and Medical Informatics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany, 2Institute for Physical and Theoretical Chemistry, University of Bonn, Bonn, Germany |
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Quaternary ammonium substrates are of huge interest in the pharmaceutical field. Here, the hyperpolarization of new fluorinated pyridinium ions was examined. The effect of the positive charged nitrogen relating to the polarization transfer inside the molecule was proven and compared with the 1H, 13C and 19F hyperpolarization examinations of 2-(3-fluoro-phenyl)-3-buten-2-ol. The observed effect can be used for localization of polarization and for the synthesis of extened MR signal enhancements. |
| 3689 | Computer #22 |
Hyperpolarized [1-13C]pyruvate and [1-13C]lactate observed using a single shot 3D pulse sequence in vivo |
1Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom, 2Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom |
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We have developed a single-shot 3D sequence for hyperpolarized 13C MRI, with a spatial-spectral (SpSp) pulse for excitation and a stack-of-spirals acquired in interleaved fashion during two spin echoes. The sequence achieved a resolution of 1.25x1.25x2.5 mm3 in vivo on a 7T animal system, where hyperpolarized [1-13C]pyruvate and [1-13C]lactate were imaged alternately at a frame rate of 2 s per metabolite. Variations are allowed in the design of the acquisition train to balance the in-plane and through-plane resolutions. This sequence allows higher temporal resolution and less RF depletion of the polarization than pulse sequences described previously. |
| 3690 | Computer #23 |
First-in-woman study of in vivo breast cancer metabolism using hyperpolarized [1-13C] pyruvate |
1Radiology, Memorial Sloan Kettering, New York, NY, United States, 2Molecular Pharmacology, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 3Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 4Radiochemistry & Imaging Probes (RMIP) Core, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 5Surgery, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 6GE Healthcare, Toronto, ON, Canada, 7GE Healthcare, Fremont, CA, United States |
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This is a first-in-woman study of hyperpolarized (HP) pyruvate to study in vivo cancer metabolism. A patient with biopsy-proven breast cancer has been scanned with a 2D dynamic hyperpolarized pyruvate protocol. This study aims to evaluate the feasibility and repeatability of HP breast cancer imaging. HP pyruvate imaging may be useful for evaluating treatment response before and after targeted as well as chemo-therapy or radiation treatment. |
| 3691 | Computer #24 |
1H-13C Independently Tuned RF Surface Coil Applied for In vivo Hyperpolarized MRI |
1Department of Radiology, University of California at San Francisco, San Francisco, CA, United States |
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This study aimed to develop a lump-element double-tuned common-mode-differential-mode (CMDM) radiofrequency (RF) surface coil with independent frequency tuning capacity for MRS and MRI applications. This CMDM coil maintained intrinsically decoupled magnetic fields, which provided sufficient isolation between the two resonators. The results from in vivo experiments demonstrated high sensitivity of both the 1H and 13C resonators. |
| Exhibition Hall | Wednesday, May 11, 2016: 10:00 - 11:00 |
| 3692 | Computer #25 |
Imaging in vitro and in vivo pH with ioversol by CEST MRI |
1Radiology Department, Second Affiliated Hospital, Shantou University Medical College, Shantou, China, People's Republic of |
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We have developed a CEST MRI method that can measure pH using ioversol, a contrast agent that is clinically approved for X-ray imaging and has been repurposed for CEST MRI studies. Using ioversol as a CEST agent, we have measured pH over a range of 6.0 - 7.8 pH units by a novel ratiometric pH MRI method, in a concentration-independent manner. We also have used this agent and CEST MRI method to measure the extracellular pH (pHe) within the liver of healthy SD rats. |
| 3693 | Computer #26 |
15N Heteronuclear Chemical Exchange Saturation Transfer MRI Imaging |
1Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD, United States, 3Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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A two-step heteronuclear enhancement approach to magnify 15N MRI signal through indirect detection of water is described. Chemical Exchange Saturation Transfer (CEST) works by continuously perturbation of the spin magnetization of the exchangeable spins, and then through chemical exchange to accumulate this perturbation on water proton for signal magnification. This perturbation is mainly limited to saturation or excitation pulse on the exchangeable protons. In this work, the signal of 15N is detected indirectly through the water signal by first inverting selectively protons scalar-coupled to 15N in the urea molecule, followed by chemical exchange of the amide proton to bulk water. |
| 3694 | Computer #27 |
Quantification of macrophage recruitment in double and single hit head and neck cancer using fluorine-19 MRI |
1Radiology, University of California, San Diego, San Diego, CA, United States, 2Molecular Imaging Inc. La Jolla, San Diego, CA, United States, 3Head & Neck Surgery, University of California, San Diego, San Diego, CA, United States |
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Head and neck carcinoma is a source of significant mortality worldwide, two prevalent subtypes include double and single hit tumors. We aimed to evaluate the role of infiltrating immune cells in worse clinical outcomes with double-hit tumor patients. A novel 19-Fluorine containing perfluorocarbon (PFC) emulsion was used to tag macrophages with high specificity and sensitivity and no background. The average number of 19F spins within the double hit tumors were approximately double compared to the single hit group. This quantifies the tumor associated macrophage burden of head and neck cancer using a PFC emulsion and proton/19F MRI. |
| 3695 | Computer #28 |
Simultaneously Trace Blood Perfusion and Glymphatic Passage by Analyzing Deuterium Oxide Perfusion Imaging with a Two-Compartment Parallel Model |
1Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, 2Nuclear Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan |
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This study tried to simultaneously trace blood perfusion and glymphatic passage by applying two-compartment parallel model (2CPM) on D2O perfusion using the new imaging strategy. Six rats were injected with D2O, and both F1 and F2 were quantified from 2CPM. The results show that F1 is highly coordinated with cerebral blood flow, while F2 is much irrelevant. Only regions near several arteries show significant F2 values, which is speculated as the paravascular pathway of CSF regulated by glymphatic system. Therefore, using 2CPM for tracing D2O might noninvasively reveal the information of both blood and CSF dynamics. |
| 3696 | Computer #29 |
Cellulose-triacetate Nanoparticles as Smart Contrast Agents for Single Cell Detection. |
1Radiology, Michigan State University, East lansing, MI, United States, 2Michigan State University, East lansing, MI, United States |
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It was demonstrated that enzymatically degradable cellulose triacetate particles offer a novel approach to contrast modulation. The use of such materials as smart contrast agents has been discussed and evidence of cellular uptake and relaxivity modification shown. |
| 3697 | Computer #30 |
Development of intravascular SPION with tunable pharmacokinetics and relaxivity for preclinical fMRI and micro-MRA |
1Biomedical Research Imaging Center, UNC Chapel Hill, Chapel Hill, NC, United States, 2Department of Neurology, University of North Carolina Chapel Hill, Chapel Hill, NC, United States, 3SOP-CNDD, UNC Chapel Hill, Chapel Hill, NC, United States |
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We have developed a simple, inexpensive method to synthesize high-performance intravascular SPION in house. We were able to tune the relaxivity and PK profile of our home-made SPION via careful surface functionalization control and came up with an optimal formulation that offered very robust and stable contrast for high resolution cerebromicroangiography and steady state CBV functional imaging. Our future studies will focus on developing novel MR-detectable inflammation markers using our home-made iron oxide as the platform material. |
| 3698 | Computer #31 |
Assessment of brain development in children with developmental delay using amide proton transfer weighted (APTw) MRI |
1Imaging Center, Beijing Children’s Hospital, Capital Medical University, Beijing, China, People's Republic of, 2Neurosection, Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, 3Philips Healthcare, Beijing, China, People's Republic of |
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Amide proton transfer weighted (APTw) imaging is a novel molecular MRI technique that can noninvasively detect cytosolic endogenous mobile proteins and peptides in myelination process. However it is not well known to brain developments in children with developmental delay using APTw MRI. The aim of our work is to explore the brain development in children with developmental delay (DD) using APTw MRI. The final conclusion shows that APTw MRI is a promising technique to assess children with DD at a molecular level. |
| 3699 | Computer #32 |
Magnetic/Upconversion Fluorescent Nanoparticle-Based Dual-Modal Molecular Probes for Imaging of Lymph Node Metastasis From Pancreatic Cancer in vivo |
1Radiology, Changhai Hospital, Shanghai, China, People's Republic of, 2Chemistry, Chinese Academy of Sciences, Beijing, China, People's Republic of, 3Clinic and Translational Medicine Center, Changhai Hospital, Shanghai, China, People's Republic of |
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Construction of the specific pancreatic cancer probe based on upconversion nanoparticles. The probes taking biocompatibility upconversion nanoparticles with unique magnetic properties as a carrier, conjugated with ATF peptide specifically targeting the uPAR. Then, its effect of detection of tumor and lymph node metastasis would be further validated in an orthotopic human pancreatic cancer xenograft model by pathology and dual-modal imaging.
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| 3700 | Computer #33 |
Dynamic PET and cortical thickness comparison between healthy controls and epilepsy patients using simultaneous PET/MR |
1Radiology, NYU School of Medicine, New York, NY, United States, 2Psychiatry, NYU School of Medicine, New York, NY, United States, 3Neurology, NYU School of Medicine, New York, NY, United States |
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Our results suggest that 1) simultaneous PET/MR imaging provides a useful imaging tool to identify regional abnormalities; 2) more information can be rendered from dynamic PET data; 3) SUVmean_late and cortical thickness are independent biomarkers for epilepsy. In general, Freesurfer and SPM are more robust in orientation and segmentation than FSL. |
| 3701 | Computer #34 |
MRI-Guided Thermosensitive Liposomal Drug Delivery for Cancer Therapy |
1Neuroimaging, King's College London, London, United Kingdom, 2Institute of Pharmaceutical Sciences, King's College London, London, United Kingdom, 3Experimental Medicine, Imperial College London, london, United Kingdom |
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We have designed and synthesised a novel liposome formulation, capable of releasing encapsulated drug on targeting/heating by focussed ultrasound (FUS) for cancer therapy and being visualised by MRI due to the incorporation of gadolinium chelates. We show the novel liposomes are targeted to tumours by FUS and MRI-visible in vivo and thus, suitable for theranostic applications in cancer. |
| 3702 | Computer #35 |
Towards Early Detection of Pancreatic Cancers by Active Feedback MR Molecular Imaging |
1Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, United States |
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Early detection of pancreatic cancers using enhanced MRI techniques increases not only the treatment options available, but also the patients’ survival rate. This can be achieved with antibody-conjugated superparamagnetic iron oxide (SPIO) nanoparticles capable of binding to early stage pancreatic cancer cells to improve imaging specificity and innovation methods that can sensitively detect SPIO to improve imaging sensitivity. The enhanced contrast from SPIO can then be used to visually assess the distribution and magnitude of SPIO-targeted tumor cells. In vivo subcutaneous and orthotopic xenografts mouse models validated the superior contrast/sensitivity and robustness of this approach towards early pancreatic cancers detection. |
| 3703 | Computer #36 |
Real Time Detection of Pancreatic Cancer-induced Cachexia using a Fluorescent Myoblast Reporter and 1H MRS Metabolic Analysis |
1Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2MD Anderson Cancer Center, Houston, TX, United States |
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Therapeutic options for cancer-induced cachexia are limited and therefore, efforts to identify signs of precachexia in cancer patients are necessary for early intervention. Here, we generated a myoblast cell line expressing a dual dTomato:GFP construct that was grafted onto the muscle of mice bearing human pancreatic cancer xenografts to provide noninvasive live imaging of events associated with cancer-induced cachexia (i.e., weight loss). 1H MRS revealed that weight loss in cachectic animals was associated with a depletion of plasma lipid, cholesterol, and valine, and decreased skeletal muscle alanine levels, which may provide informative biomarkers of cachexia. |
| 3704 | Computer #37 |
The effect of SNR optimization on cell quantification accuracy for fluorine-19 MRI sequences: bSSFP, FSE, and FLASH |
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 2Pediatrics, University of Wisconsin-Madison, Madison, WI, United States, 3Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI, United States, 4Radiology, University of Wisconsin-Madison, Madison, WI, United States, 5Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States |
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Several MRI data acquisition methods have been used for fluorine-19 (19F) MRI cell tracking and optimizing the image SNR helps mitigate low sensitivity. An optimization workflow is presented for three 19F pulse sequences based upon relaxation parameters measured in a 19F reference phantom. Bloch simulations reveal signal differences between the reference phantom and pure 19F cellular label for SNR-optimized bSSFP, FSE, and FLASH. The simulated relative errors in 19F signal suggest SNR optimization can compromise signal quantification and thus in vivo cell quantification but could provide insight for improved methods to balance the degree of spin-density weighting and SNR. |
| 3705 | Computer #38 |
Effect of exposure in hypoxia environment caused by high altitude on magnetic susceptibility in human brain assessed by quantitative susceptibility mapping |
1MR Research China, GE Healthcare, Beijing, China, People's Republic of, 2Radiology Department, Beijing Military General Hospital, Beijing, China, People's Republic of |
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Cerebrospinal fluid fraction, CBF and T2 decay have been reported to be related with hypoxia caused by high altitude in previous studies. All these biomarkers maybe associate with tissue homogeneous magnetism changes, which may result in the magnetic susceptibility changes. Quantitative susceptibility mapping (QSM) is a novel technique that allows mapping of tissue magnetic susceptibility. It has the potential to be more sensitive with respect to magnetic tissue properties than conventional magnitude-based techniques such as transverse relaxation rates. This study was designed to reveal the effect of exposure in hypoxia environment on magnetic susceptibility in human brain assessed by QSM. |
| 3706 | Computer #39 |
Iron accumulation in rat brain with frequent USPIO administration |
1Weill Cornell Medical College, New York, NY, United States, 2Tri-Institutional Training Program in Laboratory Animal Medicine and Science, New York, NY, United States, 3The Rockefeller University, New York, NY, United States |
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An observation of signal loss on functional MRI images of primates following repeated administration of ultra-small super-paramagnetic iron oxide (USPIO) particles, led us to test a hypothesis of iron accumulation in the brain by performing weekly quantitative susceptibility mapping (QSM) of rats receiving daily USPIO injections for 9 weeks. We observed rapid increase in the susceptibility values in brain ventricles and choroid plexus confirmed by serum iron measurements and histology. In light of a similar report in the literature, we recommend monitoring patients receiving iron therapy with a susceptibility imaging technique such as QSM. |
| 3707 | Computer #40 |
Comparison Study between T2*, Quantitative Susceptibility Mapping (QSM), and Histology for Postmortem Human Substantia Nigra |
1Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea, Republic of, 2Department of Anatomy, Pusan National University School of Medicine, Yangsan, Korea, Republic of, 3Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Korea, Republic of, 4Department of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology, Ulsan, Korea, Republic of, 5Department of Neurology, Pusan National University Hospital, Busan, Korea, Republic of, 6Department of Forensic Medicine, Pusan National University School of Medicine, Yangsan, Korea, Republic of |
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Selective iron deposition in the substantia nigra (SN) along with the gradual loss of neuromelanin cell (NMC) is known to be associated with neurodegenerative diseases, such as Parkinson's disease. Postmortem 40-year-old male and 70-year-old female SN tissues were scanned at various spatial resolutions with 7T MRI. The association of T2* and QSM-derived susceptibility values with quantitative NMC and iron from Perl's Prussian blue staining were investigated with precise co-registration of MRI and histology. We identified that T2* and susceptibility values for NMC and iron regions, which were segmented from histology were significantly different from corresponding values of background tissue area. |
| 3708 | Computer #41 |
Arterial spin labeling can detect discreet changes of renal perfusion after oral application of the pain medication diclofenac in healthy subjects |
1Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany, 2Clinic for Nephrology, Hannover Medical School, Hannover, Germany |
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Diclofenac is a nonsteroidal anti-inflammatory drug that is frequently prescribed to reduce inflammation and pain. It reduces the prostaglandin-synthesis and may consequently have an effect on renal perfusion. We investigated whether arterial spin labeling can detect reduction of renal perfusion after oral and topical application of diclofenac compared to baseline measurements. Ten healthy subjects underwent functional MRI of the kidney. After oral application of diclofenac renal perfusion was reduced compared to baseline measurements (321±13 vs. 345±16 ml/(min*100g), p<0.01). No significant changes were found after topical application. In conclusion, ASL can detect discreet changes of renal perfusion that occur after application of diclofenac. |
| 3709 | Computer #42 |
Drug Distribution Kinetics in the Eye assessed by 1H-MRI and 19F-MRS |
1Roche Pharma Research and Early Development, F. Hoffmann-La Roche Ltd, Basel, Switzerland |
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Drug treatment of vision impairing diseases often involves intraocular drug injection into the vitreous humour, a highly viscous gel-like matter. Drug transport within the vitreous humour has remained rather elusive although transport processes are acknowledged to play a pivotal role for treatment efficacy and adverse effects in the target tissue. Here, we devised a potentially translational approach based on contrast-enhanced 1H-MRI and 19F-MRS to quantitatively ascertain intravitreal drug distribution kinetics at the macro-scale. We provided proof-of-concept for the small drug-like molecule trifluoroethanol in isolated porcine eyes. |
| 3710 | Computer #43 |
Ultra-high field MRI enables the in vivo quantification of the efficacy of candidate promyelinating molecules in the cuprizone mouse model |
1Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Brain and Spine Institute, ICM, F-75013, Paris, France, Paris, France, 2Center for NeuroImaging Research (CENIR), Brain and Spine Institute, 75013 Paris, France, Paris, France, 3AP-HP, Saint Antoine Hospital, Department of Neurology, 184 bd Faubourg Saint Antoine, 75012 Paris, Paris, France |
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Endogenous remyelination can potentially restore rapid axonal-conduction and confer neuroprotection in chronic demyelinating diseases such as multiple sclerosis. We used T2 mapping to evaluate the ability of two candidate pharmacological agents to promote remyelination in cuprizone-demyelinated mice. Demyelination was associated with increase in signal intensity and T2 values in the corpus callosum and external capsules. T2 values showed spontaneous recovery after discontinuation of cuprizone treatment, an effect accelerated following administration of the two compounds tested. This study confirms that in vivo MRI can be used to select pharmacological agents for their therapeutic potential on remyelination. |
| 3711 | Computer #44 |
MRI Assessment of Acute Pathologic Process after Myocardial Infarction: Role of Magnetic Nanoparticle-based MRI |
1Korea Basic Science Institute, Cheongju, Korea, Republic of, 2The Catholic University of Korea, Seoul, Korea, Republic of, 3Seoul St. Mary’s Hospital and College of Medicine, Seoul, Korea, Republic of, 4Chungnam National University, Daejeon, Korea, Republic of, 5University of Science and Technology, Daejeon, Korea, Republic of |
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Myocardial infarction (MI) is the major cause of sudden death in most industrialized society. Imaging of early disease progression and investigation of relationship between myocardial necrosis and successive inflammatory response are needed for optimal treatment of MI. We conducted cardiac MR imaging of disease progression in acute MI by using three different MRI methods of Gd (LGE), Mn (ME), and iron oxide nanoparticles (MNP)-based MRI for estimation of infarcted and inflammatory regions. |
| 3712 | Computer #45 |
APT MRI of Intracranial Mass Lesions at 3T and Comparison with DCE Perfusion Parameters |
1Centre for Bio-Medical Engineering, Indian Institute of Technolgy Delhi, Delhi, India, 2Philips India Limited, New Delhi, India, 3Radiology, Fortis Memorial Research Institute, New Delhi, India |
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In the current study, Amide Proton Transfer (APT) and T1-weighted DCE perfusion MRI was performed on patients with intra-cranial mass lesions(low and high grade tumors, CNS tuberculoma, CNS lymphoma) at 3T MRI. APT maps provided a significant difference between lesion and its contra-lateral side. From the preliminary study it was observed that APT contrast was low in infection lesion followed by tumor and lymphoma. APT values showed a significant (P<0.01) difference between low and high grade tumors. A weak Inter-class correlation was observed between APT and perfusion parameters (like cbf, cbv, Ktr, Kep, ve). Therefore, APT mapping might improve diagnostic value either alone or in combination with other MRI parameters. |
| 3713 | Computer #46 |
Nuclear Overhauser Enhancement (NOE) mediated Chemical Exchange Saturation Transfer (CEST) imaging in glioma with different progression at 7T |
12nd Affilicated Hospital, Shantou University Medical College, Shantou, China, People's Republic of |
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Nuclear Overhauser Enhancement (NOE) mediated Chemical Exchange Saturation Transfer (CEST) imaging in glioma with different progression at 7T |
| 3714 | Computer #47 |
A Comparison between the UTE and PETRA Pulse Sequences for Fluorine-19 MRI at 3 Tesla |
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Division of Angiology, University Hospital of Lausanne (CHUV), Lausanne, Switzerland, 3Advanced Clinical Imaging Technology, Siemens Healthcare IM BM PI, Lausanne, Switzerland, 4LTS5, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 5Siemens Medical Solutions, NAM USA DI MR COLLAB WE, Los Angeles, CA, United States, 6Siemens Healthcare GmbH, HC DI MR R&D PLH, Erlangen, Germany, 7Department of Cardiovascular Physiology, Heinrich Heine University, Düsseldorf, Germany, 8Center for Biomedical Imaging (CIBM), Lausanne, Switzerland |
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Fluorine-19 (19F) MRI of perfluorocarbon emulsions (PFCs) with multiresonant spectra is challenging due to destructive phase interference that leads to short T2 relaxation times (<10 ms). Pulse sequences with very short echo times (≤ 100 µs) can be used to overcome this challenge. In this study, in vitro and in vivo 19F MRI obtained with both UTE and PETRA were acquired and quantitatively compared. |
| 3715 | Computer #48 |
On the Feasibility of Quantitative Dynamic Whole Body PET/MR Imaging |
1Department of Radiology, University of Wisconsin, Madison, WI, United States, 2Department of Electrical and Computer Engineering, University of Wisconsin, Madison, WI, United States, 3Department of Radiology, Johns Hopkins University, Baltimore, MD, United States |
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In this study we investigate the feasibility of FDG PET/MR as a platform for whole body dynamic quantitative PET imaging. The ability of PET/MR systems to provide truly simultaneous imaging is advantageous compared to PET/CT for serial whole body PET acquisitions in that simultaneously acquired MR images can provide additional information to PET data, such as the application of motion parameters estimated from MR images to PET images to correct for misregistration which is not possible with PET/CT. Further improvements in workflow can allow integration of multiple MR contrasts, making dynamic whole body PET/MR a highly feasible and compelling methodology. |
| Exhibition Hall | Wednesday, May 11, 2016: 10:00 - 11:00 |
| 3716 | Computer #49 |
Combined T2*-Weighted Measurements of the Human Brain and Cervical Spinal Cord with Partial Multi-Band Acceleration |
1Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany |
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Recently, an echo-planar imaging approach has been presented that covers the human brain and cervical spinal cord in the same acquisition in order to investigate the functional connectivity of the two regions. However, the repetition time of this approach (TR) usually exceeds 3 s which is not optimal for a connectivity analysis. Multi-band acceleration is a promising technique to speed up acquisitions, but most neck coil geometries limit its applicability for the cervical spinal cord. In this study, multi-band acceleration is applied to the brain slices only yielding a significantly reduced TR while retaining a good image quality in the cervical spinal cord. |
| 3717 | Computer #50 |
Comparison of Physiological Noise in Multiband-EPI and Regular EPI fMRI |
1Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2Sunnybrook Research Institute, Sunnybrook Health Science Centre, Toronto, ON, Canada, 3Rotman Research Institute, Baycrest Health Science Centre, Toronto, ON, Canada |
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Simultaneous multi-slice echo-planer imaging (EPI) or otherwise known as multiband (MB) EPI provides high temporal and/or spatial resolution in resting-state fMRI (rs-fMRI) studies by modulating and simultaneously imaging multiple slices. However, the effect of slice acceleration on "physiological noise" induced by respiration, cardiac pulsation, variations in respiratory-volume (RVT) and cardiac-rate (CRV) is still unknown. Similar to conventional parallel imaging techniques, residual aliasing occur in MB slice acceleration that could introduce spurious signals into fMRI data. We hypothesize that since a given group of simultaneously acquired slices samples the physiological noise at the same time, the effect of physiological noise may be amplified in MB-EPI. In this study we experimentally verify this hypothesis, and identify the physiological-correction strategy that best corrects this effect. |
| 3718 | Computer #51 |
Feasibility of line scanning BOLD fMRI on human subjects |
1Department of Clinical Radiology, Muenster, Germany |
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Line scanning fMRI is a novel technique to probe the BOLD signal with high temporal resolution, which has been previously demonstrated in small animals. Here, we implement line scanning fMRI on a clinical 3 T scanner and probe the BOLD response in human brain with 100 ms temporal resolution. From our data the hemodynamic response can be derived, perfectly matching the response function as observed with conventional fMRI detection methods. |
| 3719 | Computer #52 |
High resolution gradient-echo EPI using a shim insert coil at 7T: Implication for BOLD fMRI. |
1University of Pittsburgh, Pittsburgh, PA, United States, 2Siemens Medical Solution USA, INC, Pittsburgh, PA, United States |
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High degree/order shimming was applied to improve field homogeneity thereby reducing susceptibility-induced distortion in high resolution gradient-echo EPI using a shim insert coil at 7T. Use of the shim insert improved the overall homogeneity across the entire brain by 30% in comparison to conventional 1st&2nd degree/order shimming. The susceptibility-induced displacement improved by more than 2cm and the number of activated pixels increased by 150% with higher degree shimming in regions such as the anterior temporal and frontal lobes. Our study demonstrates that the use of higher order/degree shims improves GE-EPI BOLD signal at high field. |
| 3720 | Computer #53 |
DANTE-EPI for CSF Suppression in Cervical Spinal Cord BOLD fMRI at 7T |
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 3Department of Radiology, NYU Langone Medical Center, New York, NY, United States, 4Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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A major challenge in spinal cord fMRI is physiological noise due to pulsating CSF, which confounds detection of BOLD signal. In this work, we adapt DANTE to reduce CSF signal contamination in spinal cord BOLD fMRI at 7T. Absolute signal intensity, temporal SNR, and temporal cross-correlation between left and right spinal cord gray matter were measured in DANTE-EPI images at multiple pulse-train lengths and flip angles. Aggressive DANTE preparation suppresses CSF signal, but also significantly reduces spinal cord signal. More conservative DANTE preparation yields an optimal tradeoff between adequate CSF attenuation and preservation of spinal cord signal. |
| 3721 | Computer #54 |
Optimization of EPI protocols for maximum BOLD sensitivity through numerical simulations |
1Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, UCL, London, United Kingdom, 2Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany |
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fMRI studies can suffer substantially from BOLD sensitivity loss due to susceptibility-related magnetic field inhomogeneities. We developed an automated algorithm for optimising arbitrary EPI protocols with respect to BOLD sensitivity based on numerical simulations and a multi-subject field map database, saving time and expensive measurements. In contrast to previous experimental optimization approaches that were limited e.g. to z-shim, gradient polarity and slice tilt for a specific EPI protocol, this algorithm optimizes on a larger parameter space including resolution, echo time and slice orientation. Results were compared to earlier experimental approaches and verified by BOLD sensitivity measurements in healthy volunteers. |
| 3722 | Computer #55 |
Improved detection of fMRI activity in ventromedial prefrontal cortex using multi-echo EPI |
1Applications and Workflow, GE Healthcare, Munich, Germany, 2Neuroimaging Unit, Max Planck Institute of Psychiatry, Munich, Germany |
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Standard fMRI suffers from signal loss in the ventromedial and orbital prefrontal cortex, a region of special interest in affective neuroimaging. Multi-echo EPI (MEPI) is known to have several advantages over EPI. In this work, we test if MEPI is able to reach better performance in detecting task-induced activation in the ventromedial prefrontal cortex (vmPFC) during fear conditioning, known for eliciting activity in this area. We demonstrate that MEPI (by means of the weighted sum combination approach) outperforms standard EPI in vmPFC, which is highly relevant for affective neuroscience and psychiatry given its critical role in emotion regulation. |
| 3723 | Computer #56 |
Submillimeter spatial and 1 second temporal resolution in fMRI using 3D-EPI-CAIPI with cylindrical excitation |
1Spinoza Centre for Neuroimaging, Amsterdam, Netherlands, 2EPFL, Lausanne, Switzerland, 3Lausanne, Switzerland, 4Donders Institute for Brain, Cognition and Behaviour, Nijmegen, Netherlands |
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3D-EPI-CAIPI was combined with a cylindrical excitation profile to reduce the brain area from which signal is generated, and hence, the parallel imaging undersampling artefacts and signal loss. This 3D-EPI-CAIPI with cylindrical excitation can be used to acquire fMRI data with submillimetre spatial resolution, 1-second temporal resolution and very high BOLD sensitivity. |
| 3724 | Computer #57 |
Single vs Multi Echo EPI: a Head-to-Head, Within-Session Cross-Over Comparison for Task Evoked and Seed Based Connectivity Analysis |
1Department of Neuroimaging, King's College London, London, United Kingdom, 2Brain Imaging Center, Mount Sinai Hospital, New York, NY, United States |
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Resting state fMRI data is highly susceptible to low frequency noise fluctuations from motion and pulsatile physiological movement leading to inaccuracies in observed connectivity. In this study we directly compare conventional single echo EPI against a multi echo EPI (ME-EPI) acquisition and analysis method which denoises and cleans acquired fMRI time series. Task evoked and rs-fMRI data was acquired in 8 volunteers and showed improved spatial localisation and discrete clustering in ME-EPI analysis in comparison to single echo data. Furthermore, this work demonstrates the benefits of using ME-EPI for both functional activation and resting state connectivity investigations. |
| 3725 | Computer #58 |
Echo-Time Optimization in Spin Echo EPI using Hypercapnic Manipulation at 3T |
1Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2Roman Research Institute, Toronto, ON, Canada |
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The optimal echo time (TE) for spin-echo EPI (SE-EPI) BOLD is assumed to be near the tissue T2 (65–100ms at 3 T), but this was never experimentally tested. In this study, we use a hypercapnia paradigm with SE-EPI at different TEs to identify the TE that maximizes BOLD detection at 3 T. Based on the normalized percent change in BOLD signal (∆BOLD%/mmHg), BOLD contrast-to-noise ratio (CNR/mmHg) and temporal signal-to-noise ratio (tSNR), we concluded that the optimal SE-EPI TE may be much shorter than the tissue T2, and the optimal TE at 3 T is near 50ms. |
| 3726 | Computer #59 |
A comparison of time-series SNR and Nyquist ghosting with different parallel imaging autocalibration acquisition schemes in 7 T fMRI with a chin task |
1High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 2Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, United States, 3Maastricht Brain Imaging Center, Maastricht University, Maastricht, Netherlands, 4Center for Advanced Imaging, University of Queensland, Brisbane, Australia |
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The present study assesses time-series SNR and residual aliasing (ghosting) levels in accelerated EPI acquisitions at 7 T using single-shot (SS), multi-shot (MS), FLASH and FLEET autocalibration signal acquisition schemes for GRAPPA reconstruction in resting-state and in a chin task (commonly used in fMRI for presurgical planning), which elicits head motion and, consequently, changes in ΔB0. FLASH and FLEET acquisitions yielded significantly higher average tSNR values compared to SS and MS in the chin task and no significant residual aliasing enhancement in both resting-state and chin tasks. |
| 3727 | Computer #60 |
The dependence of the BOLD response transients on stimulus type and echo time |
1Cognitive Neuroscience, Maastricht University, Maastricht, Netherlands |
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Adaptation and post-stimulus undershoot observed in the BOLD signal can originate from both active neuronal and passive vascular mechanisms. Using a multi-echo GE-EPI functional MRI sequence with two distinct visual stimuli, we are able to show that not only the BOLD response magnitude but also its shape is affected by the echo-time (TE). As pure oxygenation changes predict approximately a linear scaling of the BOLD signal with TE, this finding indicates that the composition of the underlying physiological mechanisms contributing to the fMRI signal (i.e. CBF, CBV, and CMRO2) varies over time. |
| 3728 | Computer #61 |
Multiband integrated-SSFP for functional imaging at 7T with reduced susceptibility artifacts |
1State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, People's Republic of, 2Graduate School, University of Chinese Academy of Sciences, Beijing, China, People's Republic of, 3Laboratory of FMRI Technology (LOFT), Department of Neurology, UCLA, Los Angeles, CA, United States |
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BOLD fMRI based on echo-planar imaging (EPI) suffers from susceptibility artifacts that impair imaging in specific brain regions, especially severe at ultrahigh fields. Integrated-SSFP (iSSFP), which is modified from balanced SSFP (bSSFP), shows constant magnitude regardless of frequency shift and is proposed to overcome the obstacle. In our 1st experiment, iSSFP achieved better image quality without banding artifacts and more stable signal changes in visual cortex than bSSFP. In our 2nd experiment, using semantic processing task, more tissue signal and greater activations in the inferior portion of the anterior temporal lobe were detected by multiband iSSFP compared to EPI fMRI. |
| 3729 | Computer #62 |
Calibrated BOLD fMRI with an Optimized ASL-BOLD Dual-Acquisition Sequence |
1Radiology, University of Navarra, Pamplona, Spain, 2Radiology, University of Pennsylvania, Philadelphia, PA, United States, 3Neurology, University of Pennsylvania, Philadelphia, PA, United States |
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Calibrated fMRI techniques estimate task-induced changes in the cerebral metabolic rate of oxygen (CMRO2) based on simultaneous measurements of cerebral blood flow (CBF) and blood-oxygen-level-dependent (BOLD) signal changes evoked by stimulation. To determine the calibration factor M (corresponding to the maximum possible BOLD signal increase), BOLD signal and CBF are measured in response to a gas breathing challenge (CO2, O2). Here we describe an ASL dual-acquisition sequence that combines a background-suppressed 3D readout with 2D multi-slice EPI. In five subjects we found an average gray matter M-value of 8.71±1.03 and fractional changes of CMRO2 of 12.5±5% in response to a bilateral motor task. |
| 3730 | Computer #63 |
Comparison of IVIM and pCASL in the brain |
1FMRIB, NDCN, University of Oxford, Oxford, United Kingdom, 2Department of Oncology, University of Oxford, Oxford, United Kingdom |
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IVIM has been proposed as a method of imaging blood volume fraction and perfusion in the brain. In this study we directly compared both the images and the values measured with IVIM to a multi post label delay pCASL sequence in the same imaging session. Although the units are not directly comparable, the images can be visually compared, and it was hypothesised that inter-subject variability in resting CBF in grey matter across subjects would result in a positive correlation between measures from the 2 modalities. Although visually similar, no correlation was observed in the quantitative data. |
| 3731 | Computer #64 |
The effect of diffusion on quantitative BOLD parameter estimates acquired with the Asymmetric Spin Echo technique |
1FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom |
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The results of a recently described streamlined quantitative BOLD (qBOLD) technique suggest that this method may overestimate the deoxygenated blood volume (DBV), leading to an underestimate of the oxygen extraction fraction (OEF). We hypothesise that this is due to the effect of diffusion, which is assumed to be zero in the analytical qBOLD model. In this study we performed Monte Carlo simulations to investigate this hypothesis and found that DBV and OEF measurements were vessel size dependent. However, the R2’ measurements which underlie qBOLD were found to be a reliable measure of deoxyhaemoglobin content above a vessel radius of 10μm. |
| 3732 | Computer #65 |
Submillimeter resolution fMRI in the midbrain: measuring T2* changes to a stop-task |
1Universiteit van Amsterdam, Amsterdam, Netherlands, 2Max Planck Institute for Human Cognitive and Brain sciences, Leipzig, Germany, 3Spinoza Centre for Neuroimaging, Amsterdam, Netherlands |
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Multi-echo GRE was used to visualise BOLD signal changes in the midbrain, specifically targetting the subthalamic nucleus and substantia nigra, with submillimeter resolution. Midbrain clusters were very small and often only bordered the STN or SN, rather than falling robustly inside it, emphasizing the need for high spatial resolution. |
| 3733 | Computer #66 |
Characterization of ultra-high resolution Gradient Echo and Spin Echo BOLD fMRI in the human visual cortex at 7 Tesla |
1Department of Physics, University of Pisa, Pisa, Italy, 2Imago7 Research Center, Pisa, Italy, 3IRCCS Stella Maris, Pisa, Italy, 4GE Healthcare, Pisa, Italy, 5Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy |
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This study compared GRE-EPI and SE-EPI sequences with different spatial resolutions at 7T for fMRI in the visual cortex. It is demonstrated that SE-EPI yields higher specificity than GRE-EPI. However, the decreasing temporal signal-to-noise at submillimeter acquisitions affected significantly the extension of the activated volume in a SE acquisition. At this level, GRE-based functional maps showed significant increased specificity compared to standard resolutions, and a preserved cluster volume. The reduction of partial volume effects allowed the selection of an activation sub-cluster excluding the highest z-scores, which co-localized preferably in non-gray matter, potentially increasing the performance of UHF high-resolution fMRI. |
| 3734 | Computer #67 |
Whole brain measurements of the hemodynamic response function variability during a finger tapping task at 7T show regional differences in hrf profiles. |
1Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2Universite de Lausanne, Lausanne, Switzerland, 3Universite de Geneve, Geneva, Switzerland, 4Spinoza Centre for Neuroimaging, Amsterdam, Switzerland |
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The temporal properties of the BOLD response, including inter-trial variability, were studied using a 3D-EPI-CAIPI acquisition at 7T with TR=400ms. The HRFs of six different brain regions in the motor network were characterized, showing a reduced post-stimulus undershoot in the cerebellar regions of interest, as well as differences in peak height, with higher response amplitude in M1 than any other region and onset time, with the cerebellar lobule VIII response starting later than the other ROIs. Trial-to-trial variability was highest in CVIII and lowest in SI. |
| 3735 | Computer #68 |
The impact of through-slice acceleration on the optimum TE in BOLD-based fMRI: a simulation study |
1Spinoza Centre for Neuroimaging, Amsterdam, Netherlands, 2Donders Institute for Brain, Cognition and Behaviour, Nijmegen, Netherlands |
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In this simulation study we evaluate the TE that offers the optimum BOLD contrast per unit time for a given field strength (taking into account the field-specific T1, T2* and ΔT2* values) as a function of the number of slice excitations to acquire the volume (minimum TR achievable), using the Ernst angle for excitation. Generally, optimum BOLD sensitivity is found at TEs closer to T2* when shorter TRs (higher multiband acceleration factors) are employed. At longer TRs efficiency constraints tend to make the optimum TE shorter with this effect being more pronounced at lower static fields. |
| 3736 | Computer #69 |
Evaluation of PCASL Imaging and T2* Mapping for the Assessment of Cerebrovascular Reactivity in the Hippocampus |
1Center for Magnetic Resonance Research, School of Medicine, University of Minnesota, Minneapolis, MN, United States, 2Laboratory of Integrative Human Physiology, School of Kinesiology, University of Minnesota, Minneapolis, MN, United States, 3Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, United States, 4Berman Center for Clinical Research, Hennepin County Medical Center, Minneapolis, MN, United States |
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The hippocampus is significantly affected in cognitive impairment, including Alzheimer’s disease. Cerebrovascular endothelial dysfunction (CeV-ED) plays an essential role in the initiation and progression of cerebrovascular disease (CeV-D) and cognitive decline. CeV-ED can be assessed with the evaluation of cerebrovascular reactivity (CeV-R) by performing MRI studies with a respiratory challenge, such as the manipulation of end-tidal partial pressure of CO2 (PetCO2) and O2 (PetO2). In the presented studies, ASL imaging and T2* mapping were evaluated for the assessment of the CeV-R in the hippocampus to determine the benefits and disadvantages of each imaging method and to facilitate the imaging method selection for future application studies. |
| 3737 | Computer #70 |
Functional Resolution of Gradient Echo, Asymmetric Spin Echo, and Spin Echo in Functional MRI |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States |
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In BOLD fMRI, gradient-echo and spin-echo pulse sequences have been widely used due to their higher functional sensitivity and spatial specificity, however, fair comparison between SE and GRE methods has often not been made properly. In this study, we defined "functional resolution" as a quantitative metric to evaluate spatial specificity of BOLD contrast fMRI and measured it in SE, asymmetric spin-echo, and GRE. Then we conducted spatial smoothing to equalize their functional resolution and compare their functional sensitivity under the equivalent conditions. |
| 3738 | Computer #71 |
High resolution IVIM in brain using readout-segmented EPI |
1FMRIB, NDCN, University of Oxford, Oxford, United Kingdom, 2Department of Oncology, University of Oxford, Oxford, United Kingdom |
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1mm isotropic diffusion-weighted images were acquired with readout-segmented EPI at 3T to investigate the effects of partial voluming on the IVIM-derived measures of perfusion and blood volume. The maps produced showed no contrast between white and grey matter, and very high signal from CSF. Both the grey and white matter curves were adequately fitted using a monoexponential model, and only the CSF required a biexponential to fit the data. This suggests that the biexponential signal behaviour typically observed at lower resolutions may arise primarily from the CSF rather than the blood compartment. |
| 3739 | Computer #72 |
Reduction of run-to-run variability of temporal SNR in accelerated EPI time-series data through FLEET-based robust autocalibration |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, United States, 2Siemens Medical Solutions USA Inc., Charlestown, MA, United States, 3Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States |
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Temporal signal-to-noise ratio (tSNR) provides a crucial metricdetermining sensitivity of the acquisition to BOLD fMRI measurements. Ithas been shown that tSNR may vary dramatically between multiple runs ofaccelerated single-shot EPI acquisitions using single- or multi-shot EPIto acquire autocalibration or ACS data. We applied noise-to-noise ratio(NNR) measure to map run-to-run variability of acquisitions usingconventional multi-shot EPI ACS data as well as recently proposed Fastlow-angle excitation echo-planar technique (FLEET) ACS. tSNR variabilitybetween multiple runs improved in acquisitions using FLEET-ACS, providing the potential to increase sensitivity of BOLD fMRI experiments. |
| Exhibition Hall | Wednesday, May 11, 2016: 10:00 - 11:00 |
| 3740
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Computer #73 |
Identifying Foci of Brain Disorders from Effective Connectivity Networks |
1AU MRI Research Center, Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States, 2Department of Psychology, Auburn University, Auburn, AL, United States, 3Alabama Advanced Imaging Consortium, Auburn University and University of Alabama Birmingham, Birmingham, AL, United States, 4Department of Diagnostic Radiology, Yale University, New Haven, CT, United States, 5U.S. Army Aeromedical Research Laboratory, Fort Rucker, AL, United States, 6Human Dimension Division, HQ TRADOC, Fort Eustis, VA, United States |
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Brain connectivity studies report statistical differences in pairwise connection strengths. While informative, such results are difficult to interpret, since our understanding of the brain relies on region information, rather than connections. Given that large effects in natural systems are likely caused by few pivotal sources, we employed a novel framework to identify sources of disruption from directional connectivity. Using resting-state fMRI, we employed static and time-varying effective connectivities in a probabilistic framework to identify affected foci and associated affected connections. We illustrate its utility in identifying disrupted foci in Soldiers with post-traumatic stress disorder and mild traumatic brain injury. |
| 3741 | Computer #74 |
Brain Connectivity Network Dynamics Are Correlated with Cognitive Performance in Multiple Sclerosis |
1Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada, 2Pacific Parkinson’s Research Centre, University of British Columbia Hospital, Vancouver, BC, Canada, 3Department of Electrical and Computer Engineering Program, University of British Columbia, Vancouver, BC, Canada, 4Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 5Department of Radiology, University of British Columbia Hospital, Vancouver, BC, Canada, 6Department of Psychiatry, University of British Columbia Hospital, Vancouver, BC, Canada, 7Graduate Program in Counselling Psychology, University of British Columbia, Vancouver, BC, Canada, 8Neurology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada |
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Brain connectivity networks are usually estimated with the assumption that neural networks do not change over time. However, functional connectivity is inherently non-stationary, changing across time from seconds to minutes. In healthy subjects, dynamic reconfiguration of functional connectivity assessed by fMRI has been estimated and has been linked to cognitive tests, indicating that flexibility of connectivity normally contributes to cognitive performance. In this study, we applied a novel time-varying analysis to study network dynamics in healthy controls and subjects with Multiple Sclerosis (MS). |
| 3742 | Computer #75 |
Parcellation-based connectome assessment by using structural and functional connectivity |
1IMT Institute for Advanced Studies Lucca, Lucca, Italy, 2Enrico Fermi Centre, Rome, Italy, 3IRCCS Fondazione Santa Lucia, Rome, Italy, 4Institute of Digital Communications, School of Engineering, The University of Edinburgh, Edinburgh, United Kingdom, 5ISC-CNR, UOS Sapienza, Dipartimento di Fisica, Universita Sapienza, Rome, Italy |
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Connectome analysis of the human brain structural and functional architecture provides a unique opportunity to understand the organization of brain networks. In this work, we investigate a novel large scale parcellation-based connectome, merging together information coming from resting state fMRI (rs-fMRI) data and diffusion tensor imaging (DTI) measurements. |
| 3743 | Computer #76 |
Group NMF Analysis for Resting State fMRI |
1Global Research, General Electric Global Research, Bangalore, India |
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Clustering of resting state fMRI signals for extraction of functional brain networks has been showed to provide value in recent times. Independent component analysis (ICA) is the most commonly used technique to extract functional brain networks. More recently non-negative matrix factorization (NMF) has been successfully utilized for identification of brain functional networks in single-subject resting state fMRI data. NMF may provide complementary information for analyzing resting state fMRI data. However, the technique has not been extended to provide group inferences. This is non-trivial, since the components obtained from single subject NMF is not ordered. Using temporal concatenation, similar to group ICA, we introduce a new framework for back reconstruction of individual subject from group analysis using NMF. This framework will make comparisons between groups possible for NMF. |
| 3744 | Computer #77 |
Mixed ICA and Clustering Method Introduced to Study the Life Span Changes in the Within-Network Functional Connectivity of the Default Mode Network |
1Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy, 2IRCCS, Don Gnocchi Foundation, Milan, Italy |
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This study combines the independent component analysis and a local clustering method in order to study the within-network functional connectivity of the default mode network (DMN). Our results strongly support the hypothesis that the long-range FC between anterior and posterior DMN increases from the childhood to the young adulthood and slowly decreases with aging. This joint approach allowed us to obtain more detailed information about within-network FC changes among the DMN sub-regions. |
| 3745 | Computer #78 |
A novel sparse partial correlation method for simultaneous estimation of functional networks in group comparisons |
1Imaging Division, Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 2Epilepsy Division, Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 3Department of Neurology, Austin Health, Melbourne, Australia, 4Department of Medicine, University of Melbourne, Melbourne, Australia |
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We propose a novel approach, Graphical-LAsso with Stability-Selection (GM-GLASS), by employing sparse group penalties for simultaneously estimating networks from healthy control and patient groups. Simulations demonstrate that both GM-GLASS and JGMSS outperform Fisher Z-transform. Our in vivo results further show that GM-GLASS yields highest contrast of network metrics between groups, demonstrating the superiority of GM-GLASS in detecting significance group differences over JGMSS and Fisher Z-transform. Overall, by controlling confounding variations between subjects, and therefore enhancing the statistical power, our simulated and in vivo results demonstrate that GM-GLASS provides a robust approach for conducting group comparison studies. |
| 3746 | Computer #79 |
Characterizing cross session coherence in the resting-state human brain |
1Department of Biomedical Engineering, Peking University, Beijing, China, People's Republic of, 2Center for MRI Research and Beijing City Key Lab for Medical Physics and Engineering, Peking University, Beijing, China, People's Republic of |
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Previous studies suggested that the BOLD signal might be a mixture of different frequency components, but the neurophysiological basis of these components is still unclear. In this study, we attempted to quantify the similarity of the frequency profiles of the resting-state BOLD signals in different sessions by computing the cross session coherence (CSC) of these components. Our results suggested that different frequency components of BOLD signal in the brain might be associated with distinct intrinsic neuronal oscillations rather than random noise. |
| 3747 | Computer #80 |
Dynamic Reconfiguration of Intrinsic Functional Connectivity: A Probabilistic Framework |
1Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China, People's Republic of |
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Neural basis enabling flexible behavior remains largely unknown. Based on the spatiotemporal dynamics of intrinsic functional connectivity, we proposed a probabilistic modeling framework to quantify the functional flexibility and integration of different brain regions. We then applied this framework to investigate the functional representation of hand preference. Our findings revealed higher functional flexibility and integration for the preferred hand that controls cognitive-motor requirements for skilled movements. |
| 3748 | Computer #81 |
The long-term reproducibility of stimulation and resting state fMRI in the mouse |
1Singapore Bioimaging Consortium, Agency for Science, Technology & Research (A*STAR), Singapore, Singapore, 2Interdisciplinary Institute of Neuroscience & Technology (ZIINT), Zhejiang University, Hangzhou, China, People's Republic of |
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There is a need to evaluate the long-term reproducibility of stimulation and resting state fMRI in the mouse, given the technical challenges of mouse fMRI. We compared 2 sessions of scans done between 3-9 weeks apart on 7 C57BL/6 mice. The intraclass correlation (ICC) indicated significant absolute agreement for forepaw stimulation fMRI results. Interhemispheric functional connectivity scores for a large subcortical area like the CPu were also found to be reproducible, but in a small cortical area like the S1FL, reproducibility did not reach significance. Possible reasons include data coregistration mismatches due to distortion and susceptibility artifacts. |
| 3749 | Computer #82 |
Effects of Anesthesia on Functional Connectivity in Primary Somatosensory Cortex in Monkeys |
1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, 2Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 3Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States |
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Low-frequency fluctuation of resting state functional MRI (rsfMRI) signals have been linked to changes in the spontaneous neuronal activity, but their relationships have not been established. Anesthesia is known to suppress neuronal activity. Thus, by examining the effects of different levels of anesthesia on changes in inter-regional functional connectivity and the power spectra, we will be able to assess the neuronal origins of the rsfMRI signals. We carried out live anesthetized squirrel monkey experiments that measure how low frequency fluctuations and inter-regional functional connectivity within a small local network (primary somatosensory cortex) vary as isoflurane levels are altered in a small range. |
| 3750 | Computer #83 |
Chronic RF-coil and electrode implantation approach for long-term EEG-fMRI studies in rodents |
1Neurobiology, A.I.Virtanen Institute for Molecular Medicine, University of Eastern Finland, Kuopio, Finland, 2Institute of Clinical Medicine - Neurosurgery, University of Eastern Finland and Neurosurgery of NeuroCenter, Kuopio University Hospital, Kuopio, Finland, 3RAPID Biomedical GmbH Technologiepark Wuerzburg-Rimpar, Rimpar, Germany |
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Simultaneous EEG-fMRI is routinely used in clinical settings as it provides better temporal and spatial information for example when locating seizure onset zones. In pre-clinical research with small rodents, obtaining simultaneous EEG-fMRI in longitudinal studies has been challenged by a number problems including issues related to magnetic susceptibility artifacts. Here, we demonstrate a modified method for permanent MRI coil and EEG electrode implantation that is suitable for long-term chronic follow-up studies on epileptogenesis with improved data consistency across imaging and video-EEG monitoring sessions. |
| 3751 | Computer #84 |
Longitudinal resting-state fMRI and 1H-MRS characterization in the mouse brain during development of a chronic pain state |
1Institute for Biomedical Engineering, ETH and University of Zurich, Zurich, Switzerland, 2Neuroscience Center Zurich, Zurich, Switzerland, 3Institute of Pharmacology & Toxicology, University of Zurich, Zurich, Switzerland |
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We performed longitudinal resting-state fMRI and single voxel 1H-MRS in a mouse model of chronic pain derived from bone cancer. Linear mixed model analysis of independent components revealed significant functional changes mostly in limbic but also cortical networks. These findings were reproducible across strains and mirror findings from clinical studies on chronic back pain patients. 1H-MRS in the affected ventral hippocampus yielded significant decreases in glutamate, myo-inositol and glycerylophosphorylcholine concentrations in tumor-animals as well as increased glutamine levels. Given the translatability, these readouts could potentially be used to evaluate novel treatments specifically for chronic pain. |
| 3752 | Computer #85 |
Monitoring longitudinal functional reorganization of a capsular infarct rat model using resting-state fMRI |
1Southeast University, Nanjing, China, People's Republic of, 2ZhongDa Hospital, Nanjing, China, People's Republic of |
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Many resting-state fMRI studies in stroke patients claim that rs-fMRI measurements is behaviorally relevant. However, most of these studies enroll stoke patients with high heterogeneity. In this study, twenty-three rats underwent photothrombotic stroke lesioning in the PLIC with minimal affect to the nearby area. We monitor longitudinal resting-state brain activity and behavior change in this highly homogeneous white matter infarct rat model by using fcMRI and rat behavior test and try to find out the most behaviorally relevant fcMRI measurements. This project is still going on. |
| 3753 | Computer #86 |
Metabolic and functional connectivity of the rat brain during resting state assessed by simultaneous [18F]FDG-PET/MR |
1Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University of Tuebingen, Tuebingen, Germany, 2Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States |
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Recent advancement in hardware and software has enabled researchers to study systems level neuroscience using simultaneous PET/MRI. In this study, simultaneous PET/MR was used to investigate resting state networks (RSN) in rats, comparing [18F]FDG PET vs. BOLD-fMRI. RSNs such as default mode network (DMN) have been shown to be disrupted in clinical populations. ICA and ROI-analysis was used to elucidate the complementary nature between PET/MR and visualize brain connectivity. ICA PET and MR data showed prominent RSNs. However, ROI-analysis illustrated different connectivity between network-involved areas. This work suggests the complimentary nature of metabolic connectivity mapping (Cometomics). |
| 3754 | Computer #87 |
Decoupling flow effects on functional connectivity using R2* resting-sate fMRI |
1GE Global Research, Bangalore, India, 2GE Healthcare, Munich, Germany, 3GE Global Research, Niskayuna, NY, United States, 4Max Planck Institute of Psychiatry, Munich, Germany |
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In this work we compare whole brain functional connectivity (FC) estimates from R2* resting-sate fMRI (rs-fMRI) with BOLD rs-fMRI. Thirty-two healthy subjects were imaged using three-echo multi-echo echo-planar-imaging (MEPI) under institutional guidelines. FC matrices based on structural and functional brain parcellation schemes were computed for individual BOLD echoes, R2* and M (initial magnetization approximated by BOLD signal at TE=0). Results tend to show that M might be helpful to decouple flow effects. Positive between network connectivity was observed in BOLD, M and R2* derived matrices. Anti-correlations observed between networks in BOLD and M were significantly lesser in R2* derived matrices. |
| 3755 | Computer #88 |
Evaluation of Resting State Network by Pupil Diameter Monitoring during fMRI Measurements – The Relationship between the Stability of the Pupil Diameter and the Activation in the Posterior Cingulate |
1NeuroImaging & Informatics, NCGG, Ohbu, Japan, 2Human Informatics Research Institute, AIST, Tsukuba, Japan |
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The status of the resting state performance was evaluated by using pupil diameter monitoring during fMRI sessions. The activation in the posterior cingulate was higher in the subjects who kept constant pupil diameters than those with time decay, suggesting that attempts to keep eyes open and fix them to the cross mark target may demand higher consciousness level. In other resting state networks (RSNs), no significant effect was confirmed suggesting that the RSNs are robust and not strongly affected by the tension or eye closing for a short time. |
| 3756 | Computer #89 |
Resting-state fMRI fails to detect disease progression in a multicenter randomized clinical trial of Alzheimer's disease |
1Research and Early Development, Genentech, South San Francisco, CA, United States |
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RS-fMRI was implemented in two multicenter clinical trials of a novel therapeutic for AD. Although data of good quality were acquired, none of three functional connectivity metrics (FCMs) showed significant progression associated with disease in placebo-treated patients: changes in connectivity in this mild-to-moderate AD population were less than the measurement precision. Significant cognitive decline and brain atrophy were observed. Test-retest precision was similar to other single-center studies. Operational and acquisition improvements could increase data quality (though difficult in multicenter trials), but more sensitive analysis will be needed for RS-fMRI to be a useful tool for the development of AD therapeutics. |
| 3757 | Computer #90 |
Increased functional connectivity associates with the improved emotion regulation after 8-week mindfulness-based stress reduction (MBSR) training using resting-state fMRI analysis |
1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, 2Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan, 3Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei, Taiwan, 4Department of Neurology, Cardinal Tien Hospital Yonghe Branch, New Taipei City, Taiwan, 5Department of Buddhist Studies, Dharma Drum Institute of Liberal Arts, New Taipei City, Taiwan, 6Department of Mass Communication, Tamkang University, Taipei, Taiwan, 7Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, 8Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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Mindfulness-based stress reduction (MBSR) is modified from Buddhist traditions and aims to improve self-regulation. In this study, we employed the resting-state functional MRI to investigate changes of functional connectivity (FC) before and after MBSR practice, and before and after 8-week MBSR training. We hypothesized that changes in FC may reflect improvements of self-regulation after MBSR training. We found MBSR strengthened FC couplings of right subgenual anterior cingulate cortex and lateral middle orbitofrontal cortex with posterior cingulate cortex in the beginners after 8-week MBSR training. Our findings reveal an underlying neural mechanism of positive effects of MBSR practice on emotional regulation. |
| 3758 | Computer #91 |
Pattern classification reveals functional connectivity differences in expert and novice meditators |
1Neuroscience, Imaging, and Clinical Sciences, Gabriele D'annunzio University Chieti-Pescara, Chieti, Italy, 2Institute for Advanced Biomedical Technologies, Gabriele D'Annunzio University Chieti-Pescara, Chieti, Italy, 3Psychology, La Sapienza University Rome, Rome, Italy |
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In this work we explored how experience modulates ROI-based fMRI functional connectivity patterns in two different meditators groups: experts and novices. We recorded fMRI data during two styles of meditation (focused attention (Samatha), and open monitoring (Vipassana)), in two groups of subjects (Buddist Theravada Monks, and novices), and we calculated the connectivity pattern between ROIs from the AAL90 atlas. We then used a pattern classification approach to discriminate these groups and find which connections and nodes are important to classify subject experience. Regions having a role in decoding were those implicated in self-awareness and attention control. |
| 3759 | Computer #92 |
Long-term and acute cannabis effects on brain networks |
1Department of Radiology, Centre Hospitalier Universitaire Vaudois (CHUV), and University of Lausanne, Lausanne, Switzerland, 2CIBM (Centre d'Imagerie Biomédicale), Centre Hospitalier Universitaire Vaudois (CHUV) unit, Lausanne, Switzerland, 3Department of Neurology, Besancon University Hospital, Besançon, France, 4Neurology Units, Department of Medicine, University of Fribourg, Fribourg, Switzerland, 5Department of Clinical Pharmacology and Toxicology, Centre Hospitalier Universitaire Vaudois CHUV, Lausanne, Switzerland, 6CURML (University Center of Legal Medicine), UTCF (Forensic Toxicology and Chemistry Unit), Lausanne, Switzerland, 7CURML (University Center of Legal Medicine), UMPT (Unit of Psychology and Traffic Medicine), Lausanne, Switzerland, 8Department of Psychiatry, SUPAA (Service Universitaire de Psychiatrie de l'Age Avancé), CHUV, Lausanne, Switzerland, 9Department of Neurology, Icahn School of Médicine at Mount Sinai, New York, NY, United States |
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The purpose of our study was to reveal the changes in functional networks due to chronic and acute cannabis use, and to highlight the anterior insula specific involvement. We explored changes in functional connectivity by means of ICA and seed-based methods. Long-term cannabis use leads to an attenuation of the engagement of the Salience Network regions. The further decrease of activity after acute consumption can reflect the decrease of subject awareness in their performances, or a modulation of networks interplay. Modifications revealed by seed-based connectivity analysis support and clarify the insular role in cannabis addiction. |
| 3760 | Computer #93 |
Wavelet variance analysis of brain resting state temporal dynamics reveals role of precuneus to reach and sustain abnormal default-mode network activity in major depressive disorder |
1Laureate Institute for Brain Research, Tulsa, OK, United States, 2Dept. of Medicine, Tulsa School of Community Medicine, University of Tulsa, Tulsa, OK, United States, 3Tandy School of Computer Science, Dept. of Mathematics, University of Tulsa, Tulsa, OK, United States, 4College of Engineering, University of Oklahoma, Tulsa, OK, United States |
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We investigated temporal dynamics of resting-state brain activation in BOLD resting-state networks (RSNs) in patients with major depressive disorder (MDD) and healthy controls (HC). The wavelet variance analysis was applied to the RSNs time courses to assess frequency specific temporal fluctuations. Comparing to HC, MDD subjects had significantly lower fluctuation in the default-mode network (DMN) and the high-visual network in 0.031-0.125Hz and higher fluctuation in the language/auditory and the cerebellum networks in 0.125-0.25Hz and 0.0156-0.031Hz. The low DMN fluctuation in MDD was associated with high precuneus activity that triggered increase of DMN activity. |
| 3761 | Computer #94 |
Staging Alzheimer’s Disease Risk by Sequencing Brain Function and Structure, Cerebrospinal Fluid, and Cognition Biomarkers |
1biophysics, medical college of wisconsin, milwaukee, WI, United States, 2Neurology, medical college of wisconsin, milwaukee, WI, United States |
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A robust temporal ordering sequence of biomarkers for staging the Alzheimer’s disease (AD) progression risk is revealed by integrating brain function and structure, cerebrospinal fluid (CSF), and cognition biomarkers into an event-based model. In this study, we found that functional abnormality in the hippocampus and posterior cingulate cortex networks is the earliest event in the preclinical phase of AD, even antedating the detectable CSF Aβ and p-tau abnormalities; this sheds light on the link between preclinical AD status and its symptomatic onset for accurately identifying progressive AD trajectories along the disease course, given the condition that disease onset is insidious. |
| 3762 | Computer #95 |
The effect of preterm birth on the thalamocortical development during the neonatal stage： A resting-state fMRI study |
1Biomedical Engineering, Peking University, Beijing, China, People's Republic of, 2Department of Pediatrics, Daping Hospital, Third Military Medical University, Chong Qing, China, People's Republic of, 3Department of Pediatrics, Daping Hospital, Third Military Medical University, Chongqing, China, Chong Qing, China, People's Republic of, 4GE Healthcare, MR Research China, Beijing, Beijing, China, People's Republic of, 5Center for MRI Research and Beijing City Key Lab for Medical Physics and Engineering, Peking University, Beijing, China, People's Republic of |
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Preterm birth is a leading cause of cognitive impairment in childhood and is associated with cerebral gray and white matter abnormalities. Using the resting-state fMRI imaging analysis, we tested the hypothesis that preterm birth might to some extent affect the thalamo-cortical connections particularly in the thalamo-SM and thalamo-SA projections. Reduced thalamo-SM and increased thalamo-SA connectivity were found in the preterm newborns, and preterm with punctate white matter lesions (PWMLs) exhibited a more sever trend in the thalamo-SA projection. |
| 3763 | Computer #96 |
Aberrant functional connectivity of resting state networks in subclinical hypothyroidism |
1NMR Research Center, Institute of Nuclear Medicine and Allied Science, Delhi, India, 2Thyroid research centre, Institute of Nuclear Medicine and Allied Science, Delhi, India |
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Cognitive deficit in Subclinical hypothyroidism (SCH) patient is still a topic to research work upon. The present study was conducted to examine resting state networks (RSNs) in SCH using rsfMRI. SCH patients showed significantly decreased functional connectivity in right fronto-parietal network and anterior default mode network (DMN) as compared with control subjects. Our finding suggests cognitive impairment in resting state networks related to attention and emotional processing in SCH patients |
| Exhibition Hall | Wednesday, May 11, 2016: 11:00 - 12:00 |
| 3764 | Computer #1 |
Altered gray matter volume, cerebral blood flow and functional connectivity in chronic stroke patients: a multi-modal MRI study |
1MRI, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China, People's Republic of, 2GE Healthcare MR Research, Beijing, China, People's Republic of |
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In order to investigate the cerebral plasticity in chronic stroke patients well-recovered in global motor function, 29 patients and 30 healthy subjects were recruited to undergo multi-modal MRI techniques. Group comparisons in gray matter volume(GMV), cerebral blood flow(CBF) and resting-state functional connectivity(rsFC) were assessed. Compared with healthy controls, patients exhibited increased GMV in contralesional supplementary motor area, increased CBFs in contralesional superior frontal gyrus and supramarginal gyrus, and increased rsFC in contralesional middle temporal gyrus. The results suggested cerebral structure plasticity, perfusion aberrant and functional reorganization coexist in well-recovered subcortical stroke patients, which may underlie functional recovery of stroke patients. |
| 3765 | Computer #2 |
Machine learning approach to classify Alzheimer disease and Vascular Dementia using MRI quantitative metrics |
1Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, Italy, 2Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy, 3Department of Physics, University of Pavia, Pavia, Italy, 4Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy, 5Neurology Unit, C. Mondino National Neurological Institute, Pavia, Italy, 6Brain MRI 3T research center, C. Mondino National Neurological Institute, Pavia, Italy, 7Scientific Institute H. S. Raffaele, Milan, Italy, 8NMR Research Unit, Queen Square MS Centre Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom, 9Department of Emergency Neurology, C. Mondino National Neurological Institute, Pavia, Italy |
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Despite the large number of studies on dementia, efforts to define a clear profile of cognitive impairment for Vascular Dementia (VaD),as well as its differentiation from Alzheimer Disease (AD), are still poor. In this study we tested the power of imaging metrics and adopted a data mining approach, based on Diffusion Tensor Imaging and resting state fMRI, to assess the reliability of machine learning approaches for the automated diagnosis of AD and VaD. Our results show that machine learning algorithms are able to discriminate VaD from AD, representing a suitable approach to build an automated diagnostic system for dementia-like diseases. |
| 3766 | Computer #3 |
A Preliminary Study of Major Depressive Disorder Using Simultaneous PET/fMRI with Two MID Tasks in a Single Scan |
1Department of Biomedical Engineering, Tsinghua University, Beijing, China, People's Republic of, 2Department of Psychology, Stanford University, Stanford, CA, United States, 3Department of Radiology, Stanford University, Stanford, CA, United States, 4Applied Science Lab, GE Healthcare, Menlo Park, CA, United States |
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The release of dopamine during reward tasks is modulated by major depressive disorder (MDD). In this study of MDD, we used simultaneous PET/fMRI to detect the neurochemical changes of dopamine and neurovascular activity through BOLD contrast during two sequential monetary incentive delay tasks in a single scan. Several modeling methods were proposed and evaluated for dynamic PET data. Six participants with MDD were studied. The results of the group analysis of PET and fMRI show significant effects of dopamine release in ventral striatum bilaterally, close to the nucleus accumbens, and significant BOLD signals in putamen bilaterally during reward tasks. |
| 3767 | Computer #4 |
EEG-fMRI at 7T using simultaneous multislice 2D-EPI: safety and functional sensitivity at the single-subject level |
1École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2ISR-Lisboa/LARSyS/Department of Bioengineering, Instituto Superior Técnico, Lisbon, Portugal, 3Biomedical Imaging Research Center, University of Geneva, Geneva, Switzerland, 4Institute of Mathematics, Physics and Mechanics, Ljubljana, Slovenia, 5Spinoza Centre for Neuroimaging, Amsterdam, Netherlands, 6Department of Radiology, University of Lausanne, Lausanne, Switzerland, 7Department of Radiology, University of Geneva, Geneva, Switzerland |
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The enhanced BOLD sensitivity available at 7T can bring significant advantages for EEG-fMRI studies, and the use of accelerated fMRI sequences such as SMS-EPI could further boost sensitivity. This work investigated whether SMS-EPI can be safely acquired with EEG at 7T, and whether the resulting sensitivity is favorable for combined EEG-fMRI approaches. The adopted SMS-EPI sequence (1.8mm isotropic resolution, whole-brain, TRvol=1.57s) produced no temperature increases when combined with EEG. In a human, eyes-open/closed and resting-state activity patterns could be robustly detected in both modalites, and EEG-derived timecourses produced consistent BOLD predictions, even at a single-subject level with minimal spatial smoothing. |
| 3768 | Computer #5 |
A simultaneous fMRI-EEG acquisition to minimize the MR gradient artifact on human auditory system |
1Aim for the Top University Project, National Taiwan Normal University, Taipei, Taiwan, 2Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan, 3Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan, 4Advanced Magnetic Imaging Centre, Low Temperature Laboratory, Aalto University, Espoo, Finland, 5Department of Electrical Engineering and Automation, Aalto University, Espoo, Finland, 6Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan |
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Simultaneous fMRI-EEG acquisition provides a good spatial and temporal resolution from MRI and EEG respective to study the human brain function. However, the EEG signal is impaired due to the strong magnetic gradient switching of concurrent MR imaging. A simultaneous interleaved MR InI-EEG recording strategy is proposed to minimize the distortion of the EEG. Our results suggest that the proposed acquisition strategy can reveal similar BOLD contract activation but preserve better auditory evoked potentials than conventional EPI-EEG acquisition. |
| 3769 | Computer #6 |
Multimodal elucidation of rat brain function using BOLD-fMRI and CMRO2 [15O]O2-PET |
1Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan, 2Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University of Tuebingen, Tuebingen, Germany |
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The complex interplay of CMRO2, CBF and CMRO2 changes that constitute the BOLD effect are not fully unsterstood. Here we study rat brain activation using combined BOLD-fMRI and CMRO2 proportional [15O]O2-PET during the same anesthesia session. To our knowledge, such combined measurements have not been obtained before in small animals. We observed a spatial mismatch between the main activation centers as well as additional activated regions in the CMRO2-PET, not present in BOLD-fMRI. However, statistical significances of activation sites were higher in BOLD-fMRI compared to [15O]O2-PET. This work points towards a complementary nature of both methods in certain brain areas. |
| 3770 | Computer #7 |
A novel, single scanning session approach to image rat brain activity applying simultaneous [18F]FDG-PET and BOLD-fMRI |
1Department of Preclinical Imaging and Radiopharmacy, Werner Siemens Imaging Center, Eberhard Karls University, Tuebingen, Germany, 2Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka, Japan |
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Functional and metabolic processes during brain activity are still not fully understood. We established a novel protocol to image rat brain activation in a single scanning session, enabling optimal comparison of PET/fMRI data. Performing activation and baseline scans in one single scanning session is challenging due to the half-life (here [18F]FDG: 109.8 min) and decay time of PET-tracers. Applying [18F]FDG-PET and BOLD-fMRI, spatial and quantitative correlations but also mismatches between the glucose proportional PET and the fMRI activation data were found. Our results provide the basis for further studies of brain function and point towards the complementary nature of PET/MR. |
| 3771 | Computer #8 |
Simultaneous, trimodal MR-PET-EEG at 3T in humans: Glutamate drives energy consumption in the default mode network |
1Institute of Neuroscience and Medicine 4 (INM 4), Forschungszentrum Juelich GmbH, Juelich, Germany, 2Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany, 3JARA-BRAIN, Translational Medicine, Aachen, Germany, 4Department of Nuclear Medicine, RWTH Aachen University, Aachen, Germany, 5Department of Neurology, RWTH Aachen University, Aachen, Germany |
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Within the scope of this explorative pilot trial we focus on the role of GABA and glutamate within the default mode network with regard to energy consumption. In one simultaneous session MR, FDG-PET and EEG data were recorded at a 3T hybrid MR-BrainPET scanner (Siemens, Germany) equipped with a 32 channel MR-compatible EEG system (Brain Products, Germany) in 11 healthy volunteers. The Pearson correlation showed a statistically significant positive correlation between glutamate ratio and mean CMRGlu in the DMN (r = 0.678, n = 11, p = 0.022) but none to GABA. |
| 3772 | Computer #9 |
Pharmacological Modulation of Static and Dynamic Functional Connectivity: a Simultaneous PET/MRI Study |
1A. A. Martinos Center, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States, 2Center for Brain Science, Harvard University, Cambridge, MA, United States |
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In this study, we present simultaneous PET/MRI study with pharmacological challenges targeting the μ-opioid receptor system in nonhuman primates to determine the effects of opioid drug on static and dynamic functional connectivity. Mu-opioid receptor occupancy (quantified with PET) and CBV-fMRI signals show dose-dependent reductions to opioid antagonist (naloxone) challenges. Using brain regions showing PET signal changes as seeds, static FC analysis shows an increase in local (within the seed region) and distal (motor cortex) connectivity with putamen after naloxone. Dynamic FC patterns were also modulated with naloxone as indicated by weaker pairwise correlations and larger number of dynamic state transitions. |
| 3773 | Computer #10 |
Real-time ICA-based artifact correction of EEG data recorded during functional MRI |
1Laureate Institute for Brain Research, Tulsa, OK, United States, 2Electrical and Computer Engineering, University of Oklahoma, Tulsa, OK, United States, 3College of Engineering, University of Oklahoma, Tulsa, OK, United States |
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Recording EEG signals during fMRI acquisition result EEG signals contamination from imaging and BCG artifacts in addition to other types of artifacts. In this abstract we introduced a novel method for detecting and reducing artifacts using second order blind separation in real time. The algorithm was tested on EEG signals from 12 subjects and it has proven successful for reducing various types of artifacts. The proposed algorithm can be applied in real time after the average artifact subtraction of imaging and BCG artifacts for various applications that require a real-time EEG & fMRI system. |
| 3774 | Computer #11 |
Automatic EEG-assisted retrospective fMRI head motions correction improves rs-fMRI connectivity analysis |
1Laureate Institute for Brain Research, Tulsa, OK, United States, 2College of Engineering, University of Oklahoma, Norman, OK, United States, 3Center for Biomedical Engineering, University of Oklahoma, Norman, OK, United States |
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We utilized an automatic EEG-assisted retrospective motion correction (aE-REMCOR) to improve rs-fMRI connectivity analysis. The aE-REMCOR utilizes EEG data to automatically correct for head movements in fMRI on a slice-by-slice basis. We compared the results of seed-based (posterior cingulate cortex) default-mode network (DMN) connectivity analysis performed with and without aE-REMCOR. The aE-REMCOR reduced the motion-induced position-dependent error in the DMN connectivity analysis. The results show the importance of slice-by-slice fMRI motion corrections to improve rs-fMRI connectivity accuracy especially when the entire group of subjects exhibits rapid head motions, and also provide incentive for conducting simultaneous EEG&fMRI. |
| 3775 | Computer #12 |
Detecting visual evoked responses in simultaneous EEG-fMRI using Reference Layer Artefact Subtraction (RLAS) |
1Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom, 2Electrical Engineering, Qatar University, Doha, Qatar, 3Birmingham University Imaging Centre, School of Psychology, University of Birmingham, Birmingham, United Kingdom |
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Simultaneous EEG-fMRI is limited by large artefacts in EEG recordings resulting from time-varying field gradients, cardiac-related motion and head movement within the magnetic field. Reference layer artefact subtraction (RLAS) reduces artefacts at source by subtraction of artefact voltages recorded from a reference layer on which the EEG leads and electrodes are replicated. Since RLAS does not require prior knowledge of the timing of artefact occurrences, it is an ideal method for correcting pulse and movement artefacts. Here, we apply RLAS in EEG-fMRI experiments for the first time, particularly focusing upon recovery of single-trial, low-frequency, visual-evoked responses from artefact-corrupted data. |
| 3776 | Computer #13 |
Assessing the stability of neurovascular coupling: A combined fMRI/MEG approach |
1Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, United Kingdom, 22. Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom, 3Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand |
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Neurovascular coupling (NVC) is crucial to maintaining the structural and functional integrity of the brain. Using a graded contrast visual stimulus applied in magnetoencephalography (MEG) and functional MRI (fMRI), we assessed the stability of visual evoked fields (VEFs), gamma power and MRI blood flow responses. A power law was used to relate responses to stimulus contrast and describe the relationship between neuronal responses and blood flow. VEF amplitude was temporally unstable across time points. Gamma power and blood flow (ASL) responses remained stable, making gamma power-based NVC and ASL MRI measures a promising method for testing and exploring NVC in disease states. |
| 3777 | Computer #14 |
EEG-fMRI derived DMN-microstate quantifies meditation induced altered consciousness |
1Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Bangalore, India |
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Fluctuations in the ICA derived resting state networks can be visualized using simultaneous EEG fMRI. This method can thus be used to understand human consciousness which is the result of synchronous oscillation between multiple networks. EEG fMRI derived "DMN microstate" is seen to accurately assess meditation induced altered consciousness in the current study. |
| 3778 | Computer #15 |
New perspectives in simultaneous EEG-fMRI using multiband and quiet pulse sequences |
1GE Global Research, Munich, Germany, 2TUM (Technical University Munich), Munich, Germany, 3GE Healthcare, California, CA, United States |
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Three novel fMRI pulse sequences are evaluated together with simultaneous EEG acquisition, with the aim to reduce the induced EEG Gradient Artifacts (GA), increase the spatio-temporal resolution of fMRI and reduce the acoustic noise during scanning: sinusoidal GE- EPI, multiband blipped-CAIPI and single shot T2-prep RUFIS. Remarkable results were found for the T2-prep RUFIS sequence, with a significantly reduced gradient artifact amplitude, high temporal resolution and low acoustic noise level, providing eminent advantages to this multimodal technique. |
| 3779 | Computer #16 |
Mapping dynamics of epileptic seizures in GAERS using simultaneous BOLD fMRI and optical Ca2+ recordings |
1Department of Clinical Radiology, University of Münster, Münster, Germany, 2Institute of Physiology I, University of Münster, Münster, Germany |
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Simultaneous BOLD fMRI and optical Ca2+ recordings using the genetically encoded calcium indicator GCaMP were performed in a rat model of absence epilepsy (GAERS) for seizure mapping. Spike-and-wave discharge onset times and durations were derived from Ca2+ recordings and used for an event-related analysis with different hemodynamic response functions. BOLD maps showed large scale activations in cortical and subcortical areas, with delayed responses in subcortical areas. In contrast to electrophysiological recordings, Ca2+ recordings are not disturbed by MRI. They allow for cell-specific correlation with the hemodynamic response and provide a tool to obtain epileptic seizure maps with higher specificity. |
| 3780
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Computer #17 |
A novel test bed for non-BOLD functional MRI |
1Section on Quantitative Imaging and Tissue Science, DIBGI, NICHD, National Institutes of Health, Bethesda, MD, United States, 2Biophysics Program, Institute for Physical Science and Technology, University of Maryland, College Park, MD, United States, 3Section on Critical Brain Dynamics, LSN, NIMH, National Institutes of Health, Bethesda, MD, United States, 4Mathematical and Statistical Computing Laboratory, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, MD, United States, 5Department of Biomedical Engineering, Tel-Aviv University, Tel-Aviv, Israel, 6Laboratory for Functional and Molecular Imaging, NINDS, National Institutes of Health, Bethesda, MD, United States |
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Several fMRI contrast mechanisms have been proposed to measure neuronal activity more directly and accurately than BOLD fMRI. Conclusive findings supporting these non-BOLD fMRI methods have been difficult to obtain, mainly because of the dearth of a reliable and robust test system to vet and validate them. Here we describe the development and testing of a test bed for non-BOLD fMRI, in which calcium fluorescence imaging and MR acquisition can be performed simultaneously on the same organotypic cortical cultures. This experimental design makes it possible to directly correlate any candidate fMRI signal to a robust optical indicator of neuronal activity. |
| 3781
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Computer #18 |
Anesthesia increases water diffusion in wakefulness/sleep brain regions in the rat brain |
1NeuroSpin, Commissariat à l’Energie Atomique-Saclay Center, Gif-sur-Yvette, France |
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Diffusion fMRI (DfMRI) has been shown to reflect neuronal activation more directly than BOLD fMRI, showing neuronal responses even when neurovascular coupling is abolished. We compared resting state ADC and BOLD fMRI time courses under different anesthesia conditions. While BOLD fMRI showed a widespread signal increase with isofluorane and a decrease with medetomidine, the ADC increased significantly with both agents in specific regions, notably in the wakefulness/sleep network. The amount of ADC increase was correlated with the dose of anesthetic agent, suggesting the suitability of DfMRI to investigate brain resting state or pharmacological challenges quantitatively and without vascular confounding effects. |
| 3782 | Computer #19 |
Recruitment of Distinct Cortical and Subcortical Activations by Layer and Frequency Specific Optogenetic Stimulation in Primary Visual Cortex |
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China, People's Republic of, 2Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China, People's Republic of |
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Different layers in mammalian cortex have specific projections and circuit dynamics. However, how optogenetic stimulation frequencies at different infragranular layers contribute to widespread and large-scale cortical and subcortical activities remains largely unexplored. In this study, optogenetic fMRI is used to investigate layer and frequency dependent activities by stimulating excitatory neurons in different infragranular layers of visual cortex. Our results showed that layer and frequency specific optogenetic stimulation recruits distinct widespread and large-scale cortical and subcortical activations. Spatiotemporally varying optogenetic stimulation in combination with fMRI presents unique opportunities in studying the underlying mechanisms of long-range neural circuits and brain functional networks. |
| 3783 | Computer #20 |
Light-induced activation of the visual network by optogenetic fMRI (ofMRI) |
1Department of Clinical Radiology, University of Münster, Münster, Germany, 2Research Group Molecular Imaging and Optogenetics, Johannes Gutenberg-University Mainz, Mainz, Germany |
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Optogenetic fMRI is a novel tool in neurophysiology and neuroimaging. However, ofMRI is prone to light-induced artifacts. Here, the unspecific activation of the visual pathways in ofMRI in rats was investigated. It was caused by the stimulation light and was also detected in naïve rats without the presence of opsins. Visual stimulation of the eyes resulted in similar activation. Visual pathway activation by intrabrain illumination could be suppressed by additional low-level constant light applied to the eyes. We provide evidence that the activation of the visual pathways is at least partly caused by light scattered diffusely inside the brain. |
| 3784 | Computer #21 |
Development of Carbon Nanotube Optrodes to Acquire LFP and BOLD Concurrently with Optogenetic Stimulation |
1Mechanical Engineering, University of Minnesota, Minneapolis, MN, United States, 2Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, MN, United States, 3Neuroscience, University of Minnesota, Minneapolis, MN, United States |
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Carbon nanotube optrodes are under development for simultaneous optogenetics, neural recording, and fMRI BOLD signal acquisition. First-generation devices demonstrate capability in combining optogenetic stimulation and neural recording in vivo, but in vitro MR-images reveal severe susceptibility artifacts generated by terminal silver leads. New devices utilize carbon fiber wires in place of silver. Initial in vitro images of the second-generation device show a dramatic reduction of image artifacts, indicating that BOLD signal should be obtainable around the optrodes. The new devices will enable the combination of the aforementioned techniques, providing a platform for novel brain investigations. |
| 3785 | Computer #22 |
Concurrent 32-channel electrophysiological recording and fMRI in bilateral rat striatum |
1Neuroimaging Research Branch, National Institute on Drug Abuse, NIH, Baltimore, MD, United States, 2Physiology, Uni. Texas Health Science Center-San Antonio, San Antonio, TX, United States, 3Neurology, Uni. Texas Health Science Center-San Antonio, San Antonio, TX, United States |
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Despite the high clinical and pre-clinical value of fMRI, its success depends on the identification of the underlying neurophysiological basis of the fMRI BOLD signal. In previously reported simultaneous electrophysiology and fMRI studies, experiments were limited by the poor spatial resolution or poor source localization of intra-cranial or surface EEG techniques employed to record neural activity. In order to overcome these limitations, we have developed a method that allows concurrent whole brain fMRI acquisition and 32-channel intra-cerebral electrophysiological recording in the rat brain. |
| 3786 | Computer #23 |
MRI-compatible wireless multi-purpose game controller for social neuroscience fMRI experiments |
1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, 2Institute of Neuroscience, National Yang Ming University, Taipei, Taiwan |
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We developed a MRI-compatible wireless multi-purpose game controller. With the presence of the game controller, EPI shows minimal distortion and time-domain SNR degradation. Subjects’ responses were successfully recorded from a two-person hyper-scanning experiment. |
| 3787 | Computer #24 |
A new way of looking at brain connectivity. pH fMRI: myth or reality? |
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
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A new way of looking at brain connectivity. pH fMRI: myth or reality? |
| Exhibition Hall | Wednesday, May 11, 2016: 11:00 - 12:00 |
| 3788 | Computer #25 |
Loss of functional specificity in basal ganglia in Parkinson's disease: a rs-fMRI study |
1Brain and Spine Institute, CENIR, INSERM U1127/CNRS UMR7225, Sorbonne Universités, UPMC, CHU Pitié-Salpêtrière, Paris, France, 2Brain and Spine Institute, INSERM U1127/CNRS UMR7225, Sorbonne Universités, UPMC, CHU Pitié-Salpêtrière, Paris, France |
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Loss of neuronal specificity in the basal ganglia (BG) has been reported In Parkinson’s disease (PD)[1]. However, loss of specificity has not been characterized using non-invasive methods in PD. We proposed an innovative method to characterize the functional specificity of BG. We tested the hypothesis that loss of specificity may result in larger spatial extent of overlap between anatomo-functional territories in the BG. We performed population statistics to compare the extent of overlap between PD subjects and controls. As expected, the motor territories had larger extent of overlap in PD subject than in controls revealing a loss of specificity of the BG in PD. |
| 3789 | Computer #26 |
Increased activation of precuneus and posterior cingulate cortex in resting state fMRI in patients with functional movement disorders after undergoing a motor retraining program |
1Radiology, University of Louisville, Louisville, KY, United States, 2Neurology, University of Louisville, Louisville, KY, United States |
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Functional movement disorders (FMD) can be significantly reduced with a one-week motor retraining program. Our study compared resting state fMRI before and after treatment of 6 FMD patients. We found increased activity in the posterior default mode network, specifically the precuneus and posterior cingulate cortex, in 4 out of 6 patients after treatment, which correlated with clinical improvement of motor symptoms. Our findings suggest that restoration of normal movements in FMD patients are accompanied by increased default mode network activation. |
| 3790 | Computer #27 |
Demonstration of brain tumor-related NVU in both task-based fMRI and resting state fMRI |
1Division of Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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The phenomenon of neurovascular uncoupling (NVU) is a limitation of clinical fMRI, particularly in presurgical mapping. A previous study using task-based motor activation (tbfMRI) and breath hold cerebrovascular reactivity (BH CVR) mapping demonstrated that BH CVR was capable of detecting NVU in low-grade perirolandic tumors. In this study we demonstrated the effect of NVU on resting state fMRI (rsfMRI) data within the sensorimotor network through comparison to both BH CVR and task-based fMRI data. |
| 3791 | Computer #28 |
Why a clinical sign does not always correlate with lesion location? |
1Department of Neuroimaging & Interventional Radiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India, 2Bangalore, India, 3Department of Neuroimaging & Interventional Radiology, National Institute of Mental Health and Neurosciences (NIMHANS), bangalore, India, 4Department of Neurosurgery, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India |
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Understanding the degree of functional reserve in patient with brain tumor, when lesion is located in the eloquent cortex is important in presurgical evaluation to predict the surgical outcome as well reducing postoperative neurological deficits. For achieving this, a detailed knowledge of the functional topography and connectivity in whole brain level is crucial. In this study, our aim to understand the brain hyper and hypo connectivity in patients with high grade tumor who have deficits and who do not have deficits. |
| 3792 | Computer #29 |
Functional brain changes in breachers following a blast-overpressure: an acute longitudinal assessment with MRI |
1Clinical Imaging Research Centre, NUS/A*STAR, Singapore, Singapore, 2Queensland Brain Institute, Queensland, Australia, 3Clinical Imaging Research Centre, NUS, Singapore, Singapore, 4Defense Singapore Organisation, DSO, Singapore, Singapore, 5clinical Imaging Research Centre, NUS/A*STAR, Singapore, Singapore |
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Blast injury is one of the most common types of mild traumatic brain injury. In this work we have investigated the longitudinal changes induced by a blast-overpressure injury in breacher trainers using resting state functional connectivity MRI. We show that reductions in connectivity in the Thalamic and Cerebellar regions at Day 1 following a blast are regained and increased 1 month post blast. |
| 3793 | Computer #30 |
Parkinson’s disease laterality impact onto the default mode network deactivation by the audio-motor transformation |
1Human and Animal Physiology, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, 2Radiology, Medical Clinic BORIS, Kyiv, Ukraine, 3Department of extrapyramidal disorders, D. F. Chebotarev Institute of Herontology, Kyiv, Ukraine |
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Asymmetry of motor symptoms is considered a crucial criterion for PD and influence hemisphere-associated cognitive functions. DMN was shown to loose it’s functional connectivity in PD. We hypothesized that AMT play important role in switching DMN to task-related deactivation state. AMT exploration for PD laterality specific DMN connectivity analysis during movements was done. AMT and movement execution in PD evokes activation auditory cortex, SMN and pC. In PD patients DMN deactivates exceptionally at the period of motor activity. pC participates as a DMN ‘hub’ and DMN deactivation ‘switching’ trigger during AMT. PD symtoms lateralization play important role in DMN functioning. |
| 3794 | Computer #31 |
Evaluation in brain function and the correlation with depression and anxiety of obese patients using resting-state fMRI |
1Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, 2Department of Biomedical Sciences, Chung Shan Medical University, Taichung, Taiwan, 3Department of Psychiatry, Chang Gung Memorial Hospital, Chiayi, Taiwan, 4Tiawan Center for Metabolic and Bariatric Surgery, Jen-Ai Hospital, Taichung, Taiwan, 5Department of Psychology, Chung Shan Medical University, Taichung, Taiwan, 6Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan |
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Obesity has reached epidemic proportions globally to become a major public health problem. Obesity-related health problems are numerous including strokes, cardiovascular disease, diabetes mellitus, and increased risk for developing cancer. Reward mechanism of obese patients regarding functional connectivity has been declared by several studies, but few studies mentioned about the correlation between functional images and clinical indices. Thus, our study aimed to find out abnormal functional connectivity over obese patients based on amplitude low frequency fluctuation (ALFF) and regional homogeneity (ReHo) using voxel-based analysis, and the correlation between functional images and clinical indices, including body mass index (BMI) and hospital anxiety and depression scale (HADS). We found the brain functional abnormality in the obese patients compared to healthy controls, and the correlation with depression and anxiety. The potential functional imaging markers may provide guidance for managing obesity and disordered eating behaviors. |
| 3795 | Computer #32 |
Local and Distant Functional Connectivity Density Alteration in Primary Open-angle Glaucoma: A Resting-state functional MRI Study |
1Key Laboratory of Molecular Imaging, Institute of Automation, Beijing, China, People's Republic of, 2Beijing Tongren Hospital, Beijing, China, People's Republic of |
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To measure functional connectivity density maps were applied with resting-state functional MRI. Twenty-one patients and twenty-two age- and gender-matched healthy controls were evaluated by 3T MRI using resting-state blood oxygenation level dependent imaging. POAG patients showed decreased FCD values in visual cortices and increased FCD values of DMN components. This study demonstrates POAG can induce reorganization of brain function in multiple brain regions, including visual cortices and DMN. |
| 3796 | Computer #33 |
Altered Amplitude of Low-Frequency Fluctuation and functional connectivity in High Myopia: A Resting-State fMRI Study |
1Department of Interventional Radiology, China Meitan General Hospital, Beijing, China, People's Republic of, 2Department of Radiology, Peking Union Medical College Hospital, Beijing, China, People's Republic of, 3Department of Ophthalmology, Peking Union Medical College Hospital, Beijing, China, People's Republic of |
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High myopia (HM) can result in serious vision problems. To date, the pathophysiologic mechanism remains unknown. The authors tried to explore the potential locations which involved in the brain abnormalities of HM patients, through observing altered ALFF of different bands and functional connectivity of the brain by rs-fMRI. The results showed that, not only visual cortex but also multiple brain regions were noted to have abnormal changes in the brain of HM patients. In conclusion, the findings indicated that high myopia affects many functional networks, and different bands of ALFF may provide a new way to explore the underlying mechanism. |
| 3797 | Computer #34 |
Accuracy of Functional Localization in Pre-surgical Function MRI |
1Department of Imaging Physics, The University of Texas M. D. Anderson Cancer Center, Houston, TX, United States, 2Department of Diagnostic Radiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, United States |
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This study evaluates the errors associated with the spatial transformation process by using algorithms commonly applied for clinical pre-surgical fMRI. The images from nine right-handed patients with brain tumors were retrospectively analyzed. Significant differences (P<0.05) were found when comparing results from automated registration (AR) vs. coordinate matching (CM) and AR vs. AR with manual adjustment (AR, adjusted). No statistical significance was found between CM and AR, adjusted. This study established a platform for evaluating the functional localization accuracy in pre-surgical fMRI, and highlighted the necessity of quality control for the AR processing as a clinical routine. |
| 3798 | Computer #35 |
Action observation network in children with unilateral cerebral palsy: an fMRI study. |
1IRCCS Stella Maris, PISA, Italy, 2Department of Neuroscience, University of Parma, Parma, Italy, 3Department of Clinical and Experimental Medicine, University of Pisa, PISA, Italy |
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Mirror Neuron System (MNS) activation constitutes a powerful mechanism for recovery of motor deficits after stroke. We studied with fMRI the MNS (re)-organization in children with congenital unilateral cerebral palsy (UCP), using a goal-directed hand action stimulus. With respect to age-matched controls, UCP children present differences, appearing more lateralized to the dominant hemisphere as adults. The subject-specific pattern of lateralization seems related to the type and extension of the lesion and correlates negatively with the severity of the hand impairment. This paradigm might be useful to explore MNS in UCP and to monitor possible motor improvements in response to therapy. |
| 3799 | Computer #36 |
Resting-State Functional Connectivity in Patients with Treatment-Resistant Depression |
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 2State Key Laboratory of Cognitive Neuroscience and Learning& IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China, People's Republic of |
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We used a data-driven graph theoretical approach—whole-brain functional connectivity strength (FCS) mapping to investigate functional connectivity patterns in 24 patients with RDD, 40 patients with NDD, and 48 healthy comparison subjects. Our study indicated that when compared with HC, the alteration of FCS in NDD group was mainly located in the medial frontal gyrus while the alterations of RDD group were located in the non-medial frontal areas and NDD demonstrated lower FCS in the limbic regions which was not obvious in the RDD group. Meanwhile, lower FCS in the default mode network and visual recognition network was observed in the group with NDD when compared with the group with RDD. |
| 3800 | Computer #37 |
When mint smells blue and diagonal: an fMRI study on olfactory synesthesias |
1Universidad Rey Juan Carlos, Madrid, Spain |
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Neuroimaging experiments on grapheme-color synesthesia have provided evidence of structural and functional peculiarities in the synesthetic brain and several explanatory models have been proposed. Nevertheless, data from other modalities are needed in order to test their predictions. For the first time, we investigated brain activity in response to olfactory stimuli in multiple synesthetes. Results showed differential activity in areas that participate in high level visual processing, memory, language, lexical meaning and emotion. These findings suggest that the Conceptual Mediation Model and the Emotional Binding Theory may be complementary and reinforce the idea that meaning and emotion are intrinsically related processes. |
| 3801 | Computer #38 |
Data-driven model for evaluation of cerebrovascular-reserve measurement with hypercapnia BOLD |
1Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany, 2Center for Machine Perception, Faculty of Electrical Engineering, Czech Technical University in Prague, Prague, Czech Republic, 3Department, University Hospital Carl Gustav Carus, Dresden, Germany |
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Hypercapnia BOLD with the breath-holding task is a technically easier and more clinically available alternative to cerebrovascular reserve (CVR) mapping than administration of CO2 enriched air using an air-tight mask. The disadvantage is complicated data evaluation in case the subject does not adhere to the breathing protocol completely. Here, a data-driven approach for evaluation is presented that is more robust to protocol deviations and produces a reasonable CVR map in most cases where the standard model-driven approach fails. This is demonstrated on randomized evaluation of CVR maps of a group of 86 subjects with stenosis or vessel occlusion. |
| 3802 | Computer #39 |
Multi Voxel Pattern Analysis (MVPA) classification reveals distributed neural presentations of specific finger movement sequences in the human striatum: a task-based functional MRI study. |
1Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Denmark, Copenhagen, Denmark, 2Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark |
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The basal ganglia is a group of subcortical nuclei, which receives connections from almost the entire cerebral cortex. Here, we investigated the involvement of the striatum, which is the input structure of the basal ganglia, in a sequential finger movement task using fMRI. Sixteen healthy controls performed finger sequences with different complexities. Multi Voxel Pattern Analysis was used to discriminate the distributed signal in striatum and cortex. We found that the distributed signals in contra-lateral striatum are discriminative of the finger sequence performed, which points to a significant role of the basal ganglia in the control of finger sequences. |
| 3803 | Computer #40 |
Heterogeneity of hemodynamic response dynamics across the subcortical-cortical visual pathway |
1Society of Fellows, Harvard University, Cambridge, MA, United States, 2Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States, 3Department of Radiology, Harvard Medical School, Boston, MA, United States |
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The hemodynamic response is nonlinear in response to short duration stimuli, and this nonlinearity varies across cortex. To study the nonlinearities in subcortical vs. cortical structures, we performed high-resolution fMRI at 7 Tesla to characterize responses to short visual stimuli in superior colliculus (SC), lateral geniculate nucleus (LGN) and primary visual cortex (V1). Response nonlinearity was increased in SC, and response timecourses were consistently narrower in LGN than in V1. We conclude that analysis of subcortical activations using fMRI will require flexible models of the hemodynamic response, and suggest future studies to identify the neural and vascular factors contributing to these nonlinearities. |
| 3804 | Computer #41 |
Morphological component analysis of functional MRI data based on sparse representations and dictionary learning |
1Department of Electrical Engineering & Information Technology, Vietnamese - German University, Binh Duong New City, Vietnam, 2Department of Electrical Engineering, Stanford University, Stanford, CA, United States, 3Department of Radiology, Stanford University, Stanford, CA, United States |
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A data-driven method for identifying functional connectivity networks utilizing sparse representations is presented. Specifically, fMRI signals are decomposed into morphological components which have sparse spatial overlap. Allowing sparse spatial overlap between components is more physically plausible than the statistical independence assumption of the Independent Component Analysis (ICA) method. The proposed formulation is related to the Morphological Component Analysis (MCA) and uses a K-Singular Value Decomposition (SVD) algorithm for dictionary learning. Experimental results prove that the MCA-KSVD method can identify functional networks in task and resting-state fMRI and thus can be used as an alternative method for investigating brain functional connectivity. |
| 3805 | Computer #42 |
fMRI activation patterns during Successful Face-Name Recognition |
1Radiology, Penn State College of Medicine, Hershey, PA, United States, 2Neurosurgery, Penn State College of Medicine, Hershey, PA, United States |
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The contributions of distinct anatomical brain regions within the medial temporal lobe (MTL) during successful learning and recognition is poorly understood. In this research, we attempt to unravel how the MTL brain structures interact and integrate information during successful memory recall under different conditions during the performance of a face-name fMRI task. |
| 3806 | Computer #43 |
Long-term intensive training induced cortical thickness alterations in world class gymnasts |
1Department of Medical Imaging, Guangdong No. 2 Provincial People's Hospital, Guangzhou, China, People's Republic of, 2Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China, People's Republic of, 3Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, South China Normal University, Guangzhou, China, People's Republic of, 4State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China, People's Republic of |
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World class gymnasts are typical elite athletes whose motor skills and experience are much more than non-athletes. Therefore, changes in brain structure may be expected to occur after long-term intensive training. Thus, we utilized the vertex-wise and ROI-wise methods to investigate the alterations in the cortical thickness of gymnasts. We found the increased thickness in some regions of parietal, occipital, and frontal cortex in the gymnasts, and the significant correlation between thickness with years of training in right superior frontal cortex. Our study indicates that in response to long-term training, neuroanatomical adaptations and plastic changes occur in gymnasts’ cortical thickness. |
| 3807 | Computer #44 |
Effects of Hyperglycemia and Hyperinsulinemia on Amplitude of Low Frequency Fluctuations in Medial Frontal and Posterior Cingulate Cortices in Healthy Non-Diabetic Subjects |
1Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA, United States, 2Psychiatry, Harvard Medical School, Boston, MA, United States, 3Research Institute, Winthrop University Hospital, Mineola, NY, United States, 4Research Division, Joslin Diabetes Center, Boston, MA, United States, 5Division of Endocrinology, Brigham and Women's Hospital, Boston, MA, United States, 6Harvard Medical School, Boston, MA, United States |
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Our goal is to elucidate the independent effects of hyperglycemia and hyperinsulinemia on brain function. We measured whole-brain amplitude of low frequency fluctuations (ALFF) in slow-band 5 (SB5: 0.01-0.027Hz) and slow-band 4 (SB4: 0.027-0.073Hz) in 10 healthy non-diabetic subjects using resting state fMRI during fasting baseline euglycemia (EU), hyperglycemia (HG) and euglycemic hyperinsulinemia (EU-HI). SB5 fractional ALFF was decreased in the left medial frontal gyrus and right posterior cingulate/cuneus/precuneus cortices during HG, but not during EU-HI, relative to EU. Our findings may help understand brain functional adaptations to chronic hyperglycemia in diabetes, and their implications for comorbid neuropsychiatric complications. |
| 3808 | Computer #45 |
ECG-derived respiratory signal for physiological noise correction in simultaneous EEG-fMRI for enhanced mapping of epileptic activity |
1ISR-Lisboa/LARSyS and Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal, 2Department of Neurophysiology, Centro Hospitalar Psiquiátrico de Lisboa, Lisboa, Portugal |
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We propose a physiological noise model where respiratory-induced BOLD signal fluctuations were extracted from a surrogate of the respiratory signal estimated by Empirical Mode Decomposition. We optimized this model on a subject-specific basis, and evaluate its impact EEG-correlated fMRI mapping of epileptic networks, by comparing the epileptic maps obtained with and without physiological noise correction. This assessment was performed in terms of specificity and sensitivity, having been obtained not only substantial improvements for both measures, but also plausible and patients' semiology concordant epileptic networks. |
| 3809 | Computer #46 |
Pelvic floor muscles contraction assessed by fMRI |
1Bioflow Image, University of Picardie Jules Verne, Amiens, France, 2Urology, CHU Amiens, Amiens, France, 3Medical image processing, CHU Amiens, Amiens, France |
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In this work, we compared two fMRI paradigms to assess the volunteer pelvic floor muscles contraction. Paradigms suited the block-design method and the action phases consisted in contraction of the pelvic floor muscles (continuously in "Continuous" paradigm and repeated in "pulsed" paradigm) and rest phases were complete relaxation.
Results showed that there was no significant difference in cluster size between "continuous" and "pulsed" paradigms. However, Z-max was significantly higher in the “pulsed” paradigm than in the “continuous” one (p <0.001). fMRI, with a pulsed paradigm, is a suitable technique to assess volunteer pelvic floor muscles contraction. |
| 3810 | Computer #47 |
A Brain Resting State network specific T2* Study in neonatal infants |
1Centre for the Developing Brain, King's College London, London, United Kingdom, 2Department of Bioengineering, Imperial College, London, United Kingdom, 3Department of Clinical Neurosciences, Oxford University, Oxford, United Kingdom, 4Institute of Psychiatry, Kings College London, London, United Kingdom, 5Division of Imaging Sciences and Biomedical, King's College London, London, United Kingdom, 6Biomedical Image Analysis Group, Department of Computing, Imperial College, London, United Kingdom |
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Previous studies reported that, although the majority of RSNs are present at the time of normal birth, but they appear to mature at different rates with the "higher-order" networks developing later than primary sensory. T2* in neonates are up to 2 times longer than those typically seen in the mature adult brain and decrease with increasing gestational age at scan. In this study we assessed T2* for different RSNs and hypothesized that those which mature earlier on structural MRI would have shorter T2* than networks in cortical regions that develop later in gestation. |
| 3811 | Computer #48 |
How feedback, verbal instruction and reward influence learning brain self-regulation? A real-time fMRI study. |
1Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Santiago, Chile, 2Department of Electrical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, 3Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany, 4Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, India, 5Department of Psychiatry, Faculty of Medicine, Interdisciplinary Center for Neuroscience, Pontificia Universidad Católica de Chile, Santiago, Chile, 6Institute for Biological and Medical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile |
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Explicitly instructing subjects to use mental imagery and giving monetary reward are two strategies used to complement contingent neurofeedback (NF) in the process of learning to self-regulate BOLD signal with real-time fMRI NF. However, it is yet to be defined which is the optimal protocol design in rtfMRI-NF studies, critical step for potential clinical applications. The present study compares the influence of these two strategies in NF learning. Results showed a positive effect of monetary reward in BOLD signal change. Mental imagery had no significant impact in rtfMRI learning. Despite variation of strategies, brain patterns during NF training were similar. |
| Exhibition Hall | Wednesday, May 11, 2016: 11:00 - 12:00 |
| 3812 | Computer #49 |
Improved Characterization of Low-Frequency Fluctuations in Resting-State fMRI using GLM Correction of Baseline and Physiological Noise |
1Nuffield Department of Clinical Neuroscience, University of Oxford, FMRIB Centre, Oxford, United Kingdom, 2Max-Planck Institut fuer Kognitions-und Neurowissenschaften, Leipzig, Germany |
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We present a method to correct mutiband rs-fmri frequency spectra for baseline and physiological noise components using a GLM in the frequency domain. We acquired short-TR (328ms) rs-fmri whole-brain data in a group of younger and older subjects to compare the fractional amplitude of low frequency fluctuations (fALFF) between 0.01 and 0.1Hz that is thought to decline with age. We tested the ability of the GLM approach to minimise baseline and physiological noise contributions to the fALFF. GLM post-processing increased the statistical significance of the group fALFF difference. |
| 3813 | Computer #50 |
Nonlinear kernel canonical correlation analysis (kCCA) in fMRI |
1Cleveland Clinic Lou Ruvo Center for Brain Health, Las vegas, NV, United States, 2Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO, United States, 3Department of Radiology, University of Colorado-Denver, Denver, CO, United States |
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Kernel representation is an efficient method to extract nonlinear features without significantly increased computational complexity. Linear kernel CCA has been applied to fMRI data but the performance of nonlinear kernel CCA is still not clear. Here we investigate the accuracy of five types of kernel on simulated fMRI data and then apply Gaussian kernel CCA on real fMRI data. It provides a more sensitive and specific way to detect activation pattern. |
| 3814 | Computer #51 |
Addressing multi-centre image registration of 3T arterial spin labeling images from the GENetic Frontotemporal dementia Initiative (GENFI) |
1Sunnybrook Research Institute, Toronto, ON, Canada, 2London, United Kingdom, 3Dresden, Germany, 4Leiden, Netherlands, 5Amsterdam, Netherlands, 6Rotterdam, Netherlands, 7Quebec City, QC, Canada, 8Milan, Italy, 9Brescia, Italy, 10Cambridge, United Kingdom, 11Stockholm, Sweden, 12London, ON, Canada, 13Florence, Italy, 14Lisbon, Portugal |
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One obstacle in multi-centre arterial spin labeling (ASL) studies is the variability attributed to differences between vendor- or site-specific ASL implementations. This multi-centre study compares spatial registration methods from ASL to 3D-T1, to reduce the between-subject variability of cerebral blood flow (CBF) maps. Our results demonstrate that choices of image registration have profound effects on ASL data collected using different pulse sequences and/or sites. A rigid-body registration of CBF images to segmented gray matter images produced the most robust similarity outcome as a standard approach across the different ASL implementations. |
| 3815 | Computer #52 |
The Novel Anisotropic Filtering Method for Noise Reduction in fMRI Utilizing Phase Information |
1Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran, 2School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran, 3Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands, 4Neurology, UCLA, Los Angeles, CA, United States, 5School of Electrical and Computer Engineering, University of Tehran, Tehran, Iran |
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To minimize noise and artifacts in fMRI studies, authors have mostly focused on magnitude-based filtering methods and have neglected phase data due to its noisy nature. However, fMRI is a complex-valued data with also valuable phase information. Here, we propose a novel spatial weighted averaging method which uses the phase information along with magnitude to create a reference signal and utilize it iteratively to updates weights. We evaluate the method on experimental A-BOSS fMRI dataset and compared with conventional smoothing methods. The results indicate that the approach can suppress noise effectively and preserve the boundaries of active regions. |
| 3816 | Computer #53 |
Regional optimization of physiological noise models improves functional connectivity measurements in resting-state fMRI at 7T |
1ISR-Lisboa/LARSyS and Department of Bioengineering, Instituto Superior Técnico – Universidade de Lisboa, Lisbon, Portugal, 2Department of Radiology, A.A. Martinos Center for Biomedical Imaging, MGH and Harvard Medical School, Boston, MA, United States, 3INESC-ID, Instituto Superior Técnico – Universidade de Lisboa, Lisbon, Portugal |
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We develop physiological noise models based on cardiac/respiratory recordings, with lag optimization at various levels of specificity (group, dataset, regional and voxel), where regional optimization was achieved by clustering the lagged BOLD responses across the brain. We compare these models, both in terms of the spurious variance explained in the data and the specificity and reproducibility of functional connectivity measurements from three well-known resting-state networks in rs-fMRI at 7T. Voxelwise models explain the most variance in the data; however, connectivity strength specificity and test-retest reproducibility indicate that optimization at the regional/cluster level produces the most accurate networks. |
| 3817 | Computer #54 |
CSF Signal as a Complex-Valued RETROICOR Regressor Removes Unwanted Physiological Signal and Increases the Accuracy of Spatial Correlation in Complex-Valued fMRI |
1Mathematics, Statistics, and Computer Science, Marquette University, Milwaukee, WI, United States, 2Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States |
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Discarding the phase component of the time-series removes relevant biological information from a complex-valued signal. Although, commonly implemented retrospective image correction techniques fail to account for physiological artifacts in both the magnitude and phase components of the time-series. Using the CSF signal, observed during the data acquisition, as a complex-valued regressor increases the statistical power of fMRI analysis, through reducing unwanted physiological variability in the complex-valued signal of interest. The improved performance of implementing the complex-valued image correction methods is demonstrated with a comparison of magnitude-only and complex-valued spatial correlations. |
| 3818 | Computer #55 |
An overcomplete and efficient ICA for BOLD-fMRI. |
1Translational Imaging Group, University College London, London, United Kingdom, 2Dementia Research Centre, University College London, London, United Kingdom |
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Independent Component Analysis (ICA) has been proven to produce compact representations of recurrent patterns in BOLD-fMRI imaging data. Most ICA implementations used in BOLD-fMRI, however, optimize for spatial sparse decompositions rather than independent decompositions. We describe a neural-network ICA framework that optimizes directly for sparsity and also allows for overcomplete basis representation. |
| 3819 | Computer #56 |
Sample entropy (SampEn) differentiate patients with Major Depressive Disorder (MDD) from healthy controls and explores mechanism of MDD |
1Department of Biomedical Engineering, Tsinghua University, Beijing, China, People's Republic of, 2Psychiatry Department, Yu Quan Hospital, Tsinghua University, Beijing, China, People's Republic of, 3Department of Engineering Physics, Tsinghua University, Beijing, China, People's Republic of, 4Key Laboratory of Particle and Radiation Imaging, Ministry of Education, Beijing, China, People's Republic of |
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Entropy indicates system irregularity. Sample Entropy (SampEn), an estimation of entropy in a relatively robust way, was used to differentiate patients with Major Depressive Disorder (MDD) from healthy controls and to explore the mechanism of MDD. In this work, we found five clusters with significantly different SampEn in MDD group from that of control group, located in left frontal lobe, left parietal lobe, left temporal lobe, cerebellum and occipital lobe respectively, and the overall accuracy obtained with linear support vector machine formed by SampEn of those regions was 86.7%(p=0.000). |
| 3820 | Computer #57 |
Useful Metrics to Facilitate Clinical Application of Resting-state fMRI |
1Department of Medical Physics, Karolinska University Hospital, Stockholm, Sweden, 2Department of CLINTEC, Karolinska Institute, Stockholm, Sweden, 3Department of Radiology, Karolinska University Hospital, Stockholm, Sweden |
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Resting-state fMRI is useful for studying functional networks in the human brain and the abnormalities associated with various neuropsychiatric disorders. However, a lack of quantitative metrics closely associated with underlying neurophysiological characteristics has made its translation to clinical settings difficult. In this study, we propose two voxel-based metrics, namely the functional connection counter index (CCI) and connection strength index (CSI). These metrics depicts high contrast between different brain tissues and can be used for quantitative data-driven analysis to detect changes in functional connectivity related to neuropathology. |
| 3821 | Computer #58 |
A Novel Model-based Segmentation Approach for Improved Activation Detection in fMRI studies |
1pbdR Core Team, Silver Spring, MD, United States, 2Statistics, Iowa State University, Ames, IA, United States |
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Functional Magnetic Resonance Imaging (fMRI) provides a popular approach to imaging cerebral activation in response to stimuli. Reliably detecting activation is, however, not an easy proposition because only a very small proportions of voxels show true activation. These truly activated voxels are known to be spatially localized, yet incorporating this information is challenging to implement practically. We provide a model-based approach that incorporates spatial context in a practical and methodologically sound manner while postulating our a priori expectation that a certain proportion of voxels is truly active. Results on simulation experiments for different noise levels are uniformly encouraging. The methodology is also illustrated on a sports imagination experiment and shows its potential in making possible the adoption of fMRI as a clinical tool to detect awareness and improve treatment in individual patients in persistent vegetative state, such as traumatic brain injury survivors. |
| 3822 | Computer #59 |
Estimating directed functional connectivity through autoregressive models and orthogonal Laguerre basis functions |
1Department of biomedicine and prevention, University of Rome "Tor Vergata", Rome, Italy, 2Department of Information Engineering, and Research Centre “E. Piaggio”, University of Pisa, Pisa, Italy, 3Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States, 4Institute of Bioimaging and Molecular Physiology, National Research Council, Catanzaro, Italy, 5Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom, 6Department of Electronics, Informatics and Bioengineering, Politecnico di Milano, Milano, Italy, 7Department of Radiology, Martinos Center for Biomedical Imaging and Harvard Medical School, Boston, MA, United States |
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Classical multivariate Granger causality-based approaches to estimating effective functional connectivity are almost exclusively based on linear autoregressive models. In order to better represent the nonlinear, multiple-time scales interactions which concur to the formation of the BOLD signals, we present a novel approach to Granger causality based on a Volterra-Wiener decomposition with use of the discrete-time, orthogonal Laguerre basis. After validation in synthetic noisy oscillator networks, we analyze timeseries data from the "HCP-500-Subjects PTN Release", revealing a clear-cut, directed interactions between components which highlights strong driving roles of the posterior occipital-inferior parietal networks, superior parietal as well as of the novel “cognitive" cerebellar regions. |
| 3823 | Computer #60 |
A Software as a Service Cloud-based Platform for integrated analysis of T1-based segmentation and structure-based resting-state fMRI Processing |
1AnatomyWorks, LLC, Baltimore, MD, United States, 2Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, 3Center for Imaging Science, Johns Hopkins University, Baltimore, MD, United States, 4F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States |
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Brain resting state fMRI (rs-fmri) is a useful tool for research, although its clinical impact is still limited, mainly because data from single subjects is low in power. We have shown that this limitation can be addressed by “borrowing strength” from the population, specifically by eschewing voxel-based analyses in favor of assessing connectivity between atlas parcels [1]. We now present user-friendly software for signal processing, integrated with structural analysis, under a web-based platform "BrainGPS" (https://braingps.mricloud.org). Users can submit data and download results (co-registered structural and functional images, rs-fmri time-courses, and parcel-based correlation matrices) in a few minutes. |
| 3824 | Computer #61 |
Sparse Estimation of Quasi-periodic Spatiotemporal Components in Resting-State fMRI |
1Center for Functional MRI, University of California, San Diego, La Jolla, CA, United States, 2Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA, United States |
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Recent studies suggest the presence of complex recurrent spatiotemporal patterns in resting-state fMRI. These patterns may affect the performance of existing preprocessing and analysis approaches, such as global signal regression and ICA. In this work we present an approach for the sparse estimation of quasi-periodic spatiotemporal components in resting state fMRI. Our algorithm successfully estimates spatiotemporal components in a sample resting-state fMRI dataset and our results suggest that the removal of these components may represent an alternative to global signal regression. |
| 3825 | Computer #62 |
Alzheimer’s Disease is Associated with Hypo-Brain Entropy |
1Psychiatry, University of Pennsylvania, Philadelphia, PA, United States, 2Center for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, China, People's Republic of |
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Brain entropy (BEN) mapping provides a way to characterize temporal brain dynamics, and thus the health of regional brain functionality. In this study, we aimed to examine its sensitivity for differentiating Alzheimer’s disease (AD) from healthy controls, as well as its relationship to AD severity. We found reduced BEN in the limbic and prefrontal area in AD compared to controls, and a negative correlation between BEN and AD severity in a widespread area of neural cortex. These results suggest BEN as a potential biomarker for AD. |
| 3826 | Computer #63 |
Task-Driven Functional Connectivity of White Matter in Projection Pathways of the Human Brain |
1Department of Computer Science, Chengu University of Information Technology, Chengdu, China, People's Republic of, 2Brain Institute, Vanderbilt University, Nashville, TN, United States, 3Kennedy Center, Chengu University of Information Technology, Nashville, TN, United States, 4Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, 5Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 6Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 7Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States |
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Functional MRI has proven to be most effective in detecting neural activity in brain cortices on the basis of hemodynamic responses, but meanwhile has poor sensitivity in detecting neural activity in white matter. In this study, we demonstrate that MRI signals in the projection pathways have significant correlations to the primary motor cortex in finger tapping conditions, and distributions of the correlations bear clear relations with the sidedness of the task. This indicates that MRI signals in white matter may also encode neural activity, which may be detectable with sensitive methods. |
| 3827 | Computer #64 |
Differences in slow drift among echoes in multiband multiecho EPI data compromise TE-dependent analysis |
1Center for Functional Magnetic Resonance Imaging, University of California, San Diego, La Jolla, CA, United States, 2Laboratory of Brain and Cognition, Section on Functional Imaging Methods, National Institutes of Health, Bethesda, MD, United States, 3Applied Sciences Laboratory West, GE Healthcare, Menlo Park, CA, United States, 4Applications and Workflow, GE Healthcare, Munich, Germany, 5Neuroscience Imaging Center, University of Pittsburgh, Pittsburgh, PA, United States, 6Brain Imaging Center, Icahn Institute of Medicine at Mt. Sinai, New York, NY, United States, 7Applications and Workflow, GE Healthcare, Menlo Park, CA, United States |
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We recently observed differences in slow signal drift between multiple echoes in multiband multiecho EPI data. Such differences in drift compromise the TE dependence model and could impact the TE dependence analysis (e.g Multiecho Independent Component Analysis ME-ICA). We first designed a metric MEQA to quantitatively measure the observed drift differences, then investigated the effects of the drift differences on ME-ICA analysis. |
| 3828 | Computer #65 |
Reproducibility of low frequency components in scan-rescan resting state fMRI data |
1Imaging Sciences, The Cleveland Clinic, Cleveland, OH, United States |
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This work investigates the reproducibility of low frequency fluctuations by assessing the relationship of scan-rescan timeseries data taken during a resting state fMRI. We look at the relationship between various cortical regions and white matter and CSF. |
| 3829 | Computer #66 |
High Resolution fMRI with Constrained Evolution Reconstruction |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of, 2Healthcare Department, Philips Research China, Shanghai, China, People's Republic of, 3Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of |
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fMRI with high temporal and/or spatial resolution is beneficial for psychology and neuroscience studies, but is limited by various factors. Compressed Sensing (CS) based methods for accelerating fMRI data acquisition are promising, however, it may be problematic because the over-smoothing effects may contaminate the hemodynamic osculation of fMRI data. This study aimed to develop a new method, Dual Extended TRACER (DUET), based on Temporal Resolution Acceleration with Constrained Evolution Reconstruction (TRACER), for accelerating fMRI acquisitions using golden angle variable density spiral. Results show DUET can recover fMRI hemodynamic signals in even 14 fold under-sampling. Compared with other methods, DUET provides better signal recovery, higher fMRI signal sensitivity and more reliable activity maps. |
| 3830 | Computer #67 |
Complex-Valued Correlation Increases Sensitivity and Specificity in the Analysis of Low Contrast-to-Noise fMRI Time-Series |
1Mathematics, Statistics, and Computer Science, Marquette University, Milwaukee, WI, United States, 2Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States |
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The standard in fMRI is a magnitude-only statistical analysis of the data, despite evidence of task related change in the phase time-series. This study demonstrates the increased sensitivity and specificity of implementing complex-valued correlation models for low magnitude and phase contrast-to-noise ratio (CNR) values in fMRI data sets. |
| 3831 | Computer #68 |
Modeling Resting Cerebral Perfusion from BOLD Signal Dynamics During Hyperoxia |
1Departments of Radiology & Clinical Neurosciences, University of Calgary, Hotchkiss Brain Institute, Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, AB, Canada, 2Montreal Neurological Institute, Montreal, QC, Canada |
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In this work we demonstrate the use of BOLD-fMRI during hyperoxia to obtain perfusion parameters, including CBF, CBV, and MTT. During BOLD imaging, subjects breathing from a respiratory circuit inhaled air whose oxygen content was increased from 21% to 70%. The exhaled oxygen concentration was processed to obtain an arterial input function, and the concentration of bound oxygen in the venous blood was determined by modeling the BOLD time series. Through deconvolution modeling we were able to obtain measurements of CBF, venous CBV, and MTT within expected ranges. |
| 3832 | Computer #69 |
Mean-Shift Clustering Technique For fMRI Activation Detection |
1University of Minnesota, Minneapolis, MN, United States, 2University of Iowa, Iowa City, IA, United States |
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It has been shown the application of Mean-Shift Clustering (MSC) to fMRI analysis can increase detection sensitivity in low contrast to noise situations. In this study, MSC was utilized with a feature space containing both temporal and spatial features to further increase its detection power. If successful, the proposed technique can improve detection in techniques that inherently have low CNR, such as non-proton fMRI or non-BOLD fMRI. |
| 3833 | Computer #70 |
Deterministic Estimation of Spatiotemporal Motifs in Resting-State fMRI |
1Electrical and Computer Engineering, University of California San Diego, La Jolla, CA, United States, 2Center for Functional MRI, University of California San Diego, La Jolla, CA, United States |
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In resting-state fMRI data, dynamic quasi-periodic spatio-temporal patterns have previously been identified in both animal and humans with potential links to infra slow electrical activity. These prior studies used an iterative pattern-finding algorithm that employed heuristic learning rules for the dynamic adjustment of correlation thresholds. Here we present a novel deterministic non-iterative approach for estimating spatiotemporal motifs in resting-state fMRI data without the need for heuristic learning rules. |
| 3834 | Computer #71 |
A Systematic Investigation on the BOLD Contrast in S1- and S2-SSFP fMRI |
1Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran, 2School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran |
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Non-balanced SSFP can provide banding artifact free images, with reduced sensitivity to B1 inhomogeneity and SAR level. Recently, non-balanced SSFP which is known by the S1 and S2 signals, has been utilized for fMRI. In this study to model the BOLD contrast in S1- and S2-SSFP fMRI a Monte Carlo simulation has been performed. It will enable us to accurately investigate the dependence of the BOLD contrast on vessel size and acquisition parameters. Results are in accordance with the reported experimental values and show the increased sensitivity to capillary-sized vessels for only S2 signal. |
| 3835 | Computer #72 |
Monte Carlo Simulation for A-BOSS fMRI |
1Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran, 2School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran |
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Averaged-BOSS fMRI has been proposed as an alternative to BOSS fMRI to eliminate its spatial coverage problem. The feasibility of A-BOSS has been previously investigated. Due to the complexity presented in A-BOSS fMRI, in this work a Monte Carlo simulation has been performed for a comprehensive investigation on its achievable functional contrast and to compare the results with S1 and S2 SSFP fMRI. The obtained results show the superior absolute signal change for A-BOSS and demonstrate the desirable acquisition parameters. |
| Exhibition Hall | Wednesday, May 11, 2016: 13:30 - 14:30 |
| 3836 | Computer #1 |
Motion insensitive quantification of liver proton density fat-fraction using a single-shot 2D technique |
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States, 3Global MR Applications and Workflow, GE Healthcare, Madison, WI, United States, 4Medicine, University of Wisconsin-Madison, Madison, WI, United States, 5Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 6Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 7Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States |
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In this study, we developed and validated a “single-shot” sequential 2D-chemical shift-encoded MRI (CSE-MRI) technique for motion-insensitive quantification of liver proton density fat fraction (PDFF). A phantom of 11 vials with varying PDFF demonstrated equivalent PDFF between 2D- and 3D-CSE-MRI. Fifteen subjects underwent five different CSE-MRI acquisitions: 3D-single-breathhold (BH), slice-interleaved 2D-single-BH and free-breathing (FB), and sequential 2D-single-BH and FB. PDFF was measured and averaged across all nine Couinaud liver segments. Good agreement was observed in PDFF between all 2D-CSE-MRI acquisitions and 3D-CSE-MRI. Qualitative motion artifact evaluation demonstrated significantly superior scores for free-breathing “single-shot” sequential 2D-CSE-MRI compared to free-breathing slice-interleaved 2D-CSE-MRI. |
| 3837
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Computer #2 |
Free-Breathing Liver Fat Quantification Using an Undersampled Multi-Echo 3D Stack-of-Radial Technique |
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, 2Physics and Biology in Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 3Biomedical Engineering, King's College London, London, United Kingdom, 4Siemens Healthcare, Erlangen, Germany, 5Siemens Healthcare, Los Angeles, CA, United States |
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Non-alcoholic fatty liver disease is the leading cause of chronic liver disease. Multi-echo Cartesian MRI methods can non-invasively quantify liver fat, but are susceptible to motion artifacts and limited by breath hold (BH) imaging. We have developed a new free-breathing (FB) liver fat quantification method using non-Cartesian 3D stack-of-radial imaging. To reduce scan time, we undersampled data up to a factor of R=3. In healthy subjects, mean fat quantification was statistically equivalent among different R. Initial comparisons with spectroscopy show good agreement. Our new technique can potentially achieve accurate whole-liver fat quantification within a fast 1-minute FB scan. |
| 3838
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Computer #3 |
Detection of Reduction in Liver Stiffness as a Result of Weight Loss Surgery using MR Elastography |
1Radiology, University of Wisconsin, Madison, WI, United States, 2Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN, United States, 3Pathology, University of Wisconsin, Madison, WI, United States, 4Tacoma General Pathology, Tacoma, WA, United States, 5Radiology, University of California, San Diego, CA, United States, 6Surgery, University of Wisconsin, Madison, WI, United States, 7Virginia Commonwealth University, Surgery, VA, United States, 8Surgery, University of California, San Diego, CA, United States, 9Computational and Applied Statistics Laboratory, University of California, San Diego, CA, United States, 10Medical Physics, University of Wisconsin, Madison, WI, United States, 11Biomedical Engineering, University of Wisconsin, Madison, WI, United States, 12Medicine, University of Wisconsin, Madison, WI, United States, 13Emergency Medicine, University of Wisconsin, Madison, WI, United States |
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This study tracked changes in liver stiffness in morbidly obese patients undergoing bariatric surgery. 22 patients undergoing bariatric surgery were recruited for MRI studies including MR elastography (MRE) at 2 time points: 1-2 days prior to and 6 months after bariatric surgery. Changes in liver stiffness as measured by MRE were compared to intraoperative biopsies which were performed to assess relevant histological features (steatosis, inflammation and fibrosis) and their relation to liver stiffness. Follow-up measurement of liver stiffness 6 months after bariatric surgery showed statistically significant reductions in liver stiffness. Patients with biopsy confirmed liver fibrosis, inflammation and features of NASH exhibited the largest reductions in liver stiffness. |
| 3839 | Computer #4 |
Is fat a confounding factor for MOLLI T1 measurements in the liver at 3 Tesla? |
1RDM Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom, 2Translational Gastroenterology Unit, University of Oxford, Oxford, United Kingdom |
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The balanced steady-state free precession (bSSFP) sequence at 3T causes water and fat signals to be out of phase when TR=2.3 ms. Since the modified Look-Locker inversion recovery (MOLLI) mapping uses bSSFP readouts, the T1 of voxels that contain both fat and water is influenced by the choice of this TR. Simulations, phantom experiments and measurements collected from patients undergoing bariatric surgery were used to assess the impact of hepatic lipid content on liver MOLLI T1 values. |
| 3840 | Computer #5 |
Feasibility of utilizing heterogeneity of hepatic stiffness in 3D MR elastography to improve detection of liver fibrosis in pediatric patients with nonalcoholic fatty liver disease |
1Liver Imaging Group, Department of Radiology, University of California, San Diego, School of Medicine, San Diego, CA, United States, 2Computational and Applied Statistics Laboratory, University of California, San Diego, San Diego, CA, United States, 3Department of Pediatric, University of California, San Diego, San Diego, CA, United States, 4Departments of Radiology, Mayo Clinic, Rochester, MN, United States |
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We evaluated the feasibility of utilizing heterogeneity of hepatic stiffness in 3D MR elastography to improve detection of liver fibrosis in a cohort of 70 children with NAFLD. Children were dichotomized into two classes of fibrosis. We characterized the heterogeneity of hepatic stiffness by fitting a bi-Gaussian model to the histogram of hepatic stiffness. Features from the bi-Gaussian model and the known class labels were used to develop a support vector machine (SVM) classification model to predict fibrosis. We demonstrated that the SVM model has better overall classification performance than the calculated mean hepatic stiffness as measured by AUROC. |
| 3841 | Computer #6 |
Proton-density fat-fraction quantification of the liver in the presence of ferumoxytol at 1.5T and 3T |
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Radiology, University of Yamanashi, Yamanashi, Japan, 3Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 4Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 5Medicine, University of Wisconsin-Madison, Madison, WI, United States, 6Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States |
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This study evaluated the accuracy of liver proton-density fat-fraction (PDFF) quantification in the presence of ferumoxytol. Seven healthy subjects underwent MRI scans immediately before injection of ferumoxytol and one day after injection. Our results indicate that confounder-corrected chemical shift-encoded MRI PDFF estimates exhibit a small but significant bias in the presence of ferumoxytol. This bias could be due to differential shortening in the T2* of water and fat signals. Therefore, investigators attempting to create human models of iron and fat within the liver by administering ferumoxytol to patients with fatty liver should be aware of this potential source of bias. |
| 3842 | Computer #7 |
Impaired hepatic arterial buffer response in a rodent model of chronic liver disease: assessment using caval subtraction phase-contrast MRI at 9.4T |
1UCL Centre for Medical Imaging, University College London, London, United Kingdom, 2Department of Medical Physics, University College London Hospitals NHS Trust, London, United Kingdom, 3UCL Institute for Liver and Digestive Health, University College London, London, United Kingdom, 4UCL Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom |
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Total liver blood flow (TLBF) is closely regulated in health so that reductions in portal venous (PV) flow are buffered by compensatory rises in hepatic arterial (HA) flow. In this study we use caval subtraction phase-contrast MRI to estimate TLBF and HA flow in cirrhotic rats and demonstrate an impaired HA buffer response after administering terlipressin, a vasopressin analogue used clinically used to reduce PV flow in portal hypertension. |
| 3843 | Computer #8 |
Effect of choosing an in-phase vs. a default echo time in 2D MR elastography to estimate hepatic stiffness |
1Liver Imaging Group, Department of Radiology, University of California, San Diego, School of Medicine, San Diego, CA, United States, 2Computational and Applied Statistics Laboratory, University of California, San Diego, San Diego, CA, United States, 3Department of Pediatric, University of California, San Diego, San Diego, CA, United States, 4NAFLD Translational Research Unit, Division of Gastroenterology, University of California, San Diego, San Diego, CA, United States, 5Departments of Radiology, Mayo Clinic, Rochester, MN, United States |
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To investigate the effect of different echo times (TE) in 2D MR elastography (2D MRE) to estimate hepatic stiffness, two 2D MRE scans were acquired in 50 patients using a 3T GE scanner, one with a default TE value of 20.1 ms (default-TE), and with a nearest in-phase TE value of 20.6 ms (IP-TE). Wave-image quality of each scan was measured quantitatively by ROI size. We demonstrated that 2D MRE with an in-phase TE provides slightly higher wave-image quality in patients with high PDFF, and potentially may be advantageous for fibrosis assessment in NAFLD. |
| 3844 | Computer #9 |
Deferiprone has a dose-dependent effect on liver iron concentration assessed by MRI |
1Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy, 2Azienda Ospedaliero-Universitaria Ospedali Riuniti "Umberto I-Lancisi-Salesi", Ancona, Italy, 3Fondazione di Ricerca e Cura "Giovanni Paolo II", Campobasso, Italy, 4Policlinico "Paolo Giaccone", Palermo, Italy, 5Policlinico “Casilino", Roma, Italy, 6Arcispedale “S. Anna”, Ferrara, Italy, 7Ospedale Civile “Spirito Santo”, Pescara, Italy, 8Policlinico "G. Martino", Messina, Italy |
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The aim of this multi-centre study was to retrospectively assess in thalassemia major (TM) if deferiprone (DFP) had a dose-dependent effect on liver iron concentration (LIC) assessed by quantitative magnetic resonance imaging (MRI). We found out that the percentage of patients that worsened their status was significantly higher in patients with ≤ 75 mg/kg/d than in patients with > 75 mg/kg/d (26.6% vs 7.7%; P=0.016). So, the worsening in MRI LIC can be prevented by increasing the dose of deferiprone above the widely used regimen of 75 mg/kg body weight. |
| 3845 | Computer #10 |
Standardized approach for region-of-interest-based measurements of proton-density fat-fraction and R2* in the liver |
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Radiology, Mayo Clinic, Rochester, MN, United States, 3Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 4Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 5Medicine, University of Wisconsin-Madison, Madison, WI, United States, 6Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States |
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This study evaluated the reproducibility of different region-of-interest (ROI) sampling methods for MRI-based proton-density fat-fraction (PDFF) and R2* (1/T2*) measurements in the liver. 53 patient liver MRI datasets were retrospectively analyzed using ROI sampling methods that have been previously reported. Patients were not suspected of having hepatic steatosis or liver iron overload. Our results demonstrate improved measurement repeatability when the sampling area of the liver is increased by using multiple, large ROIs. Therefore, ROI-based measurements of liver PDFF and R2* should strive to sample the largest possible area of liver by using ROIs that are large in size and number. |
| 3846 | Computer #11 |
R2* of liver fat and water compared to proton density fat fraction estimated by 1H MRS |
1Department of Radiology, University of California, San Diego, San Diego, CA, United States, 2Department of Medicine, University of California, San Diego, San Diego, CA, United States |
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MRI based methods of estimating hepatic proton density fat fraction (PDFF) measure only one R2* value, as the R2* of fat and water are assumed to be identical. MRS can estimate the R2* of both fat and water. Liver MRS spectra were fitted with constraints derived from those used in MRI, and water R2* and fat R2*eff (the effective fat R2* that would be measured by MRI) were compared to PDFF. We found that water R2* was independent of PDFF, while fat R2*eff was weakly and inversely correlated with PDFF. |
| 3847 | Computer #12 |
The Feasibility Study of Liver Cirrhosis Stage Using Quantitative 3D Whole-Liver T1ρ Mapping at 3.0T |
1Shandong University, Jinan, China, People's Republic of, 2Shanghai Key Laboratory of Magnetic Resonance and Department of Physics, East China Normal University, Shanghai, China, Shanghai, China, People's Republic of, 3Philips Healthcare, shanghai, China, Shanghai, China, People's Republic of, 4Shangdong Medical Imaging Research Institute, Jinan, China, People's Republic of |
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Liver cirrhosis is an abnormal liver condition that the liver would repair it through the deposition of collagen, proteoglycans, and other macromolecules in the extracellular matrix [1]. The risk of liver cancer is greatly increased once cirrhosis develops. A non-invasive method that can objectively and simply assessment and grade the liver fibrosis is clinically required. T1ρ relaxation time has been proven to relevant with the macromolecular composition and proton exchange of tissues[2]. It may play as a non-invasive biomarker to investigate liver fibrosis. The first whole-liver study was carried out on 1.5T MR Scanner [3]. The purpose of our study was to implement the T1ρ method with whole-liver coverage that is breathing-hold free, and to initially apply the method to evaluate severity of whole-liver cirrhosis non-invasively at 3.0T. |
| 3848 | Computer #13 |
Liver parenchymal T1: repeatability and studies in a rodent model of chronic liver disease at 9.4T |
1UCL Centre for Medical Imaging, University College London, London, United Kingdom, 2UCL Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom, 3Department of Medical Physics, University College London Hospitals NHS Trust, London, United Kingdom, 4UCL Institute for Liver and Digestive Health, University College London, London, United Kingdom |
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There is a growing interest in the use of hepatic parenchymal T1 for the assessment of hepatic fibrosis. Using Look-Locker T1 measurements at 9.4T in a rat model of cirrhosis, we demonstrate that these measurements are repeatable and significantly different in animals with and without chronic liver disease. |
| 3849 | Computer #14 |
Feasibility of Breath-hold Quantitative Susceptibility Mapping on Hepatic Iron quantification |
1Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, People's Republic of, 2Brain Imaging and Analysis Center,Duke University, Durham, NC, United States, 3MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China, People's Republic of, 4Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, China, People's Republic of |
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The purpose of this study was to estimate the Quantitative susceptibility mapping (QSM) in hepatic iron evaluation, compared with R2 based Liver concentration estimation (Ferriscan LIC). 7 Patients were scanned on a 1.5 T MR System using a GRE sequence and a SE sequence, for QSM and Ferriscan analysis respectively. QSM algorithm provided susceptibility values estimate. Approximate slices were selected according to the corresponding cross-section on the Ferriscan LIC report. Then ROIs were drawn on QSM images according to LIC maps. Significant positive correlation was observed between QSM and Ferriscan LIC ( R2 = 0.8). |
| 3850 | Computer #15 |
THE EVALUATION OF PORTAL HYPERTENSION USING QUANTITATIVE MAGNETIC RESONANCE IMAGING (MRI) |
1SPMIC, School of Physics & Astronomy, University of Nottingham, Nottingham, United Kingdom, 2NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom, 3Royal Derby Hospital, Derby, United Kingdom, 4Department of Radiology, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom |
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The hepatic venous pressure gradient (HVPG) is the only validated measure to assess portal pressure but this is invasive and not widely available. Here, we use non-invasive MR parameters as a surrogate for portal pressure. Longitudinal relaxation time (T1) measures of the liver and spleen, phase contrast measures of splanchnic and collateral flow, and ASL measures of perfusion are correlated against HVPG measures in 30 patients. Liver tissue T1 is shown to be positively correlated with HVPG (p<0.001). Combining T1 measures with splenic artery velocity using a simple linear model, it is shown that HVPG can be non-invasively assessed. |
| 3851 | Computer #16 |
MRI Evaluation of Acetaminophen Induced Liver Failure in Mice using T1 Mapping and Stable Gadoxetate Disodium Administration |
1Radiology, Michigan State University, East Lansing, MI, United States, 2Pathobiology & Diagnostic Investigation, Michigan State University, East Lansing, MI, United States |
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We are developing an MRI method to measure acetaminophen toxicity in the liver. We obtained T1 maps using the clinically approved contrast agent gadoxetate disodium (Eovist). The contrast agent was administered by infusion to maintain a steady liver concentration throughout the T1 mapping. Mice with acetaminophen toxicity had higher T1 and heterogeneous gadoxetate disodium uptake compared to healthy controls. This is a promising method for quantifying drug induced liver damage in vivo. |
| 3852 | Computer #17 |
Comparison of R2* of liver water and fat using 1H MRS |
1Department of Radiology, University of California, San Diego, San Diego, CA, United States, 2Department of Medicine, University of California, San Diego, San Diego, CA, United States |
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To estimate hepatic proton density fat fraction (PDFF), MRI techniques acquire multi-echo, gradient-echo images, assuming the R2* of fat and water to be identical. Liver MRS spectra were fitted with constraints derived from those used in MRI to examine this assumption. We compared fat R2*eff (the effective fat R2* that would be measured by MRI) with water R2* and found that water R2* and fat R2*eff were correlated. There was no significant difference between water R2* and fat R2*eff, supporting the assumption that when measuring PDFF using MRI, fat and water R2* can be treated as identical. |
| 3853 | Computer #18 |
Iron measurements by quantitative MRI-R2* at 3.0 and 1.5 T |
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 2Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 3Biochemistry, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 4Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States, 5Siemens Healthcare AG, Hamburg, Germany, 6Philips Medical Care, Hamburg, Germany, 7Radiology, Children’s Hospital & Research Center Oakland, Oakland, CA, United States |
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We are investigating the suitability of a 3.0 T imager for iron measurements over the whole range of possible iron concentrations in the liver and spleen iron. For liver iron measurements in severely overloaded patients with LIC > 2400 µg/gliver or > 15 mg/gdry weight, 1.5 Tesla imagers are better suited than 3.0 Tesla systems. |
| 3854 | Computer #19 |
A prospective study comparing R2* derived Liver iron concentration(LIC) with noise-corrected post processing of data against FerriScan reported LIC in patients with liver iron overload. |
1UHN,University of Toronto, Toronto, ON, Canada, 2Siemens Germany, Erlangen, Germany, 3UHN, Toronto, ON, Canada |
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MRI is currently utilised as a non-invasive method for liver iron concentration (LIC) estimation and has essentially replaced liver biopsy. FerriScan derived LIC is considered the “gold standard” but has associated increased costs and delay results from required external data transmittal. There is no universal agreement or standardization of R2* derived LIC methods. We describe an optimized R2* method with noise corrected post processing of data for LIC estimation with simultaneous comparison to FerriScan derived LIC. Our results show very good correlation between R2* LIC and FerriScan LIC with potential for substitution of the latter with our R2* technique. |
| 3855 | Computer #20 |
Agreement between MRE-estimated liver stiffness using 2D GRE and 2D SE-EPI pulse sequences at 3T |
1Liver Imaging Group, UCSD, San Diego, CA, United States, 2Computational and Applied Statistics Laboratory, San Diego Supercomputer, UCSD, San Diego, CA, United States |
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In this study, agreement between MRE-estimated liver stiffness using 2D GRE and SE-EPI pulse sequences at 3T was examined in 30 adults with histology-confirmed nonalcoholic fatty liver disease (NAFLD) enrolled in a research registry. Results show that liver stiffness values obtained from both the sequences agree closely across a range of liver stiffness values for adults with NAFLD, although agreement tends to diverge at higher stiffness values. Differences at higher liver stiffness values were not explained by differences in image wave quality. |
| 3856 | Computer #21 |
Assessment of liver fibrosis by MRI tagging of cardiac-induced motion: preliminary results |
1Centre de recherche du Centre hospitalier de l'Universite de Montreal, Montreal, QC, Canada, 2Department of Radiology, Radio-Oncology and Nuclear Medicine, Universite de Montreal, Montreal, QC, Canada, 3Philips Healthcare Canada, Montreal, QC, Canada, 4Centre hospitalier de l'Universite de Montreal, Montreal, QC, Canada, 5Department of Gastroenterology and Hepatology, Universite de Montreal, Montreal, QC, Canada, 6Department of Medicine, Division of Gastroenterology, McGill University Health Centre, Montreal, QC, Canada, 7Department of Pathology, Centre hospitalier de l'Universite de Montreal, Montreal, QC, Canada, 8Department of Pathology and Cellular Biology, Universite de Montreal, Montreal, QC, Canada |
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Elastography for the staging of liver fibrosis is optimized for the right liver and requires additional hardware. Using MRI tagging, the displacement and strain of liver tissue induced by cardiac motion was quantified with the Harmonic Phase (HARP) method. Of the four schemes tested for the extraction of a single measure of strain, one was especially promising, as it showed high correlation with fibrosis stages (Spearman’s ρ=-0.913), as well as a significant p-value for dichotomized diagnosis of ≥F3 fibrosis (p=0.03). These preliminary results suggest that strain measurements could be used as a diagnostic tool for the staging of liver fibrosis. |
| 3857 | Computer #22 |
Assessment of fibrotic liver using T1rho mapping: a rat model study |
1Radiology Dept, Sun Yat-sen Memorial Hospital, Guangzhou, China, People's Republic of, 2Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of, 3Philips Healthcare, Guangzhou, China, People's Republic of |
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To find out the relationship among T1rho, liver fibrosis stages and liver function, MRI including T1rho sequence was performed in 32 CCl4 induced liver fibrosis SD rat models and 12 SD rats of control group. Laboratory test related to liver function were done before execution and liver was taken out for pathology evaluation. Liver fibrosis was staged according to staging systems for rodents. Results showed that T1rho could be used to diagnose early liver fibrosis (>F2) and correlation was significant between T1rho values and both liver fibrosis stage and blood serum parameters. |
| 3858 | Computer #23 |
The effect of long diffusion time on the diffusion measurements of fibrotic human liver |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of, 2Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand, 3Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 4Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, People's Republic of |
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To examine whether different diffusion times would yield different sensitivities in detecting the pathological alterations in tissue microstructure during liver fibrogenesis in human livers at 3 T. MRI including single-shot SE and simulated echo acquisition mode (STEAM) DWI EPI sequences were performed on 10 healthy volunteers and 19 liver fibrotic patients. One-way ANOVA with Turkey’s multiple comparison tests were employed to compare quantitative measurements between the volunteers and patients with different diffusion times. Results showed that diffusion measurements with higher diffusion times will be more sensitive as a biomarker to detect the pathological alterations in tissue microstructure in fibrotic patients. |
| 3859 | Computer #24 |
Improving Liver Iron Estimates with a Muscle-based Proton Density Estimate |
1Biomedical Engineering, University of Southern California, Sierra Madre, CA, United States, 2Cardiology, Boston Children's Hospital, Boston, MA, United States, 3Pediatrics, Harvard School of Medicine, Boston, MA, United States, 4Cardiology, Children's Hospital of Los Angeles, Los Angeles, CA, United States, 5Biomedical Engineering, University of Southern California, Los Angeles, CA, United States |
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CPMG-based R2 (1/T2) estimates are traditionally insensitive to tissue iron load. We show that the application of a T1-corrected, skeletal muscle-based proton density constraint increases the sensitivity of R2 for iron quantitation in phantoms and human subjects. This method leads to a fundamentally different R2-LIC (liver iron concentration) calibration curve than has previously been applied to CPMG fit data. |
| Exhibition Hall | Wednesday, May 11, 2016: 13:30 - 14:30 |
| 3860 | Computer #25 |
Accelerated Segmented Diffusion-Weighted Prostate Imaging for Higher Resolution, Better Geometric Fidelity, and Multi-b Perfusion Quantification |
1Department of Biomedical Engineering, Akdeniz University, Antalya, Turkey, 2Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States, 3Department of Radiology, University of Gothenburg, Gothenburg, Sweden |
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An accelerated multi-shot diffusion imaging sequence and reconstruction scheme was developed for prostate imaging, allowing improvements in spatial resolution, geometric-fidelity and b-factor coverage to be achieved within a short scan time. Two-fold improvement in spatial resolution and three-fold improvement in geometric fidelity were obtained as compared to single-shot EPI, in twelve prostate cancer patients. In contrast to the standard protocol, which involves separate scans with high (b=1400 and 0 s/mm2) and intermediate (b=500 and 0 s/mm2) diffusion weighting, the proposed accelerated protocol yielded an additional 8 b-factors in half the scan time (5 min 43 s vs. 11 min 48 s). |
| 3861 | Computer #26 |
Bone Metastasis of Prostate Cancer: Comparing Readout-Segmented EPI (RESOLVE) Whole-Body DWI with ECT |
1Radiology Department, Changhai Hospital, Shanghai, China, People's Republic of, 2Application Department, Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China, People's Republic of, 3MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China, People's Republic of |
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Bone metastasis is a leading cause of morbidity and mortality for patients with metastatic prostate cancer. Early detection of bone metastasis plays a key role in the assessment of treatment methods and prognosis. This study aims to evaluate the diagnostic efficiency of readout-segmented whole body diffusion weighted imaging in the detection of bone metastases for patients with newly diagnosed high-risk or biochemical recurrent prostate cancer. The result shows that RESOLVE whole-body DWI has higher sensitivity, specificity and accuracy in bone metastasis detection than bone scintigraphy using 99mTc-MDP (BS). |
| 3862 | Computer #27 |
Restriction spectrum imaging improves MRI-based prostate cancer detection |
1Radiology, UCSD, San Diego, CA, United States, 2Kansas City, KS, United States, 3Radiology, Naval Medical Center San Diego, San Diego, CA, United States, 4Urology, UCSD, San Diego, CA, United States, 5Urology, UT San Antonio, San Antonio, TX, United States, 6Radiology, UCLA, Los Angeles, CA, United States, 7Pathology, UCSD, San Diego, CA, United States |
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Restriction Spectrum Imaging is an advanced, multiple b-value, diffusion technique which allows improved reader performance in the identification of prostate cancer when combined with current standard of care imaging, or performs comparably to current imaging practice when used alone. |
| 3863 | Computer #28 |
Inter-scanner reproducibility of parameters from advanced models of DW-MRI in a multi-centre study |
1MRI, Royal Marsden Hospital, Sutton, United Kingdom, 2Division of Radiotherapy and Imaging, Cancer Research UK Cancer Imaging Centre, Institute of Cancer Research, London, United Kingdom, 3Department of Radiology, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom, 4Imaging Department, Imperial College Healthcare NHS Trust, London, United Kingdom |
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The repeatability and inter-scanner reproducibility of fitted parameters from mono-exponential and non-mono-exponential (stretched exponential, kurtosis and bi-exponential) models of diffusion-weighted MRI signal attenuation were assessed in healthy volunteers and patients with advanced ovarian cancer imaged using MRI scanners from three manufacturers. Repeatability of ADC estimates, evaluated in abdominal organs in healthy volunteers, was good on all three scanners. Estimates of DDC and α from the stretched exponential model, Dk from the kurtosis model and D from the bi-exponential model showed comparable repeatability to ADC on all three scanners; the standard deviation of differences in k was comparable across three scanners. Repeatability of f, D* and fD* was poor on all three scanners. ADC estimates showed no significant differences between the three scanners in data from patients or healthy volunteers. Significant differences were observed between scanners in α, k, D and f in data from healthy volunteers. In lesions, there was a significant difference in k between scanners. Differences between parameters estimated from different scanners should be considered in multi-centre studies. |
| 3864 | Computer #29 |
In vivo prostate cancer detection and grading using Restriction Spectrum Imaging |
1Radiology, UCSD, San Diego, CA, United States, 2Urology, UCSD, San Diego, CA, United States, 3Pathology, UCSD, San Diego, CA, United States, 4Urology, UT San Antonio, San Antonio, TX, United States, 5Radiology, UCLA, Los Angeles, CA, United States |
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Restriction Spectrum Imaging, an advanced multiple b-value diffusion technique, demonstrates greater sensitivity and specificity for discriminating between tumor and normal prostate than conventional ADC or Ktrans. |
| 3865 | Computer #30 |
MR Apparent Diffusion Coefficient (ADC) Quantification is an Imaging Biomarker Predicting Gleason Score grade in Patients with Prostate Cancer undergoing MRI-guided prostate biopsy |
1Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States, 2Interventional MRI Program, Emory University Hospital, Atlanta, GA, United States |
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The study objective is to investigate magnetic resonance Apparent Diffusion Coefficient Quantification (ADC) in prostate lesions and to correlate the values with the results of MRI-guided prostate targeted sampling. A prospective cohort of patients presenting with persistently elevated or rising serum prostate specific antigen (PSA) and at least one lesion suspicious for prostate cancer that underwent MRI guided targeted biopsy was evaluated. Thirty-five consecutive patients were recruited presenting with 179 suspicious lesions. ROC curve analysis demonstrates that ADC predicts the presence of malignancy and allows grade stratification and therefore, behaves as a non-invasive imaging biomarker. |
| 3866 | Computer #31 |
Differences in perfusion fraction in different grade of prostate cancer assessed by DWI |
1Cell Biology and Neurosciences, Istituto Superiore di Sanita', Rome, Italy, 2Radiological Sciences, Oncology and Pathology, Sapienza University of Rome, Rome, Italy |
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To date, most clinical DW-MRI studies have employed a monoexponential model for data analysis, which produces the ADC parameter for assessing diffusion characteristics whose value correlate with Gleason scores in prostate cancer. The intravoxel incoherent motion (IVIM) model introduce a fast diffusing component in the signal due to perfusion effects, but the application of this method is not yet widespread included in clinical practice. This study was aimed at measuring the water diffusion in tissue separating and estimating the perfusion component by adopting a simple protocol easy to be implemented in clinical practice and evaluating its diagnostic performance |
| 3867 | Computer #32 |
Prostate Cancer Detection and Gleason Upgrading on 3T In-Bore MRI-guided Prostate Biopsy Compared to TRUS Prostate Biopsy in Men with Elevated PSA |
1UCLA, Los Angeles, CA, United States |
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MR guided Prostate Biopsy (MRgBx) yielded a Gleason upgrading in 37.5% of the patients with prior GS6 biopsy tumors. Overall diagnostic yield of MRI guided prostate biopsy was 58.3%. Men with positive MRgBx had tumors which were larger in size, lower ADC value, and higher T2, DWI and overall score compared to men with negative MRgBx. PiRADS reporting is an accurate measure to predict positive MR guided biopsy targets. |
| 3868 | Computer #33 |
Fast T2 mapping for the diagnosis of prostate cancer by using 3.0T MRI |
1Radiology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China, People's Republic of, 2Philips Research NA, Cambridge, MA, MA, United States |
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Quantitative T2 values has the potential to reliably and reproducibly differentiate prostate abnormalities,such as prostate cancer (PCa) , benign prostate hyperplasia（BPH）and normal prostate tissue (NPT). We used k-t-T2 technique to obtain the T2 maps and tested the diagnostic performance of T2 mapping in differentiating PCa from NPT and BPH in the peripheral zone.We found the T2 values is quite useful for cancer discrimination with, for example, a threshold T2 of 68.3 ms yielded a sensitivity of 94% and a specificity of 98% for PCa discrimination. |
| 3869 | Computer #34 |
Objective response following interventional oncology treatments: A practical approach to apply response criteria through MR imaging |
1Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States |
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MR plays a key role in patients with abdominal visceral malignancies, regarding management, assessing therapy response and surveillance Standardized follow-up criteria and imaging techniques should be applied to patients with abdominal malignancies, taking into account the primary neoplasm and current therapeutic strategies Adequate knowledge of response evaluation criteria for malignancies including WHO, EASL, RECIST and mRECIST criteria is crucial for adequate patient surveillance. |
| 3870 | Computer #35 |
Clinical Utility of mDIXON TSE and mDIXON FFE in Pediatric and Fetal, Neuro, Body, and Musculoskeletal MRI |
1Radiology, Phoenix Children's Hospital, Phoenix, AZ, United States, 2MRI, Philips Healthcare, Highland Heights, OH, United States |
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mDixon sequences allow for improved MR imaging in Pediatric MR. |
| 3871 | Computer #36 |
Feasibility of an automated tissue segmentation technique in a longitudinal weight loss study |
1Radiology, UCSD, San Diego, CA, United States, 2AMRA, Linkoping, Sweden, 3Surgery, UCSD, San Diego, CA, United States, 4UCSD, San Diego, CA, United States, 5University of Wisconsin, Madison, Madison, WI, United States |
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To address the problems inherent in manual methods, a novel, semi-automated tissue segmentation image analysis technique has been developed. The purpose of this study was to demonstrate the feasibility and describe preliminary observations of applying this technique to quantify and monitor longitudinal changes in abdominal adipose tissue and thigh muscle volume in obese adults during weight loss. Abdominal adipose tissue and thigh muscle volume decreased during weight loss. As a proportion of body weight, adipose tissue volumes decreased during weight loss. By comparison, as a proportion of body weight, thigh muscle volume increased. |
| 3872 | Computer #37 |
Body Composition Analysis In Large Scale Population Studies using Dixon Water-Fat Separated Imaging |
1Department of Medical and Health Sciences (IMH), Linköping University, Linköping, Sweden, 2Center for Medical Image Science and Visualization (CMIV), Linköping, Sweden, 3Department of Biomedical Engineering, Linköping University, Linköping, Sweden, 4Department of Life Sciences Faculty of Science and Technology, University of Westminster, London, United Kingdom |
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Water-fat separated MRI, based on Dixon imaging techniques enables high soft-tissue contrast and the separation of fat and muscle compartments. This study investigate the feasibility and success-rate of one recently described method for MR data-acquisition and body composition analysis, in a large-scale population study. The first 1,000 subjects in the UK Biobank imaging cohort were scanned, quality assured and included for body composition analysis. Volumes of visceral adipose tissue, abdominal subcutaneous tissue, and thigh muscles were calculated. This study showed that the rapid MR-examination was sufficiently robust to achieve very high success-rate for body composition analysis. |
| 3873 | Computer #38 |
Automated MR Scanner Workflow of combined Chest, Abdomen and Pelvis Exams: First Clinical Experience |
1Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland, 2University of Zurich, Zurich, Switzerland, 3Oncology Application Predevelopment, Siemens Healthcare, Erlangen, Germany |
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An increasing demand for time-efficient and standardized MRI drives the development of automated MRI-workflows. The purpose of this study was to evaluate the feasibility of such a novel automated scanner-workflow for multi-station MRI. The scanner automatically detects the body regions selected and sequences are automatically adjusted to patient’s size and breath-holding capacity to generate optimal image quality. In 20 patients scanned with a multi-station protocol (chest, abdomen, and/or pelvis), image quality was good to excellent and complete body region coverage was achieved in 95% of patients. This nearly “single-button” automated multi-station MRI could open new possibilities in the diagnostic process. |
| 3874 | Computer #39 |
MR based body composition analysis correlates ayurvedic phenotyping |
1NMR, All India Institute of Medical Sciences, New Delhi, India, 2Endocrinology, All India Institute of Medical Sciences, New Delhi, India, 3Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, India, 4Anatomy, All India Institute of Medical Sciences, New Delhi, India |
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The world is entering an era of personalised medicine and phenotyping individuals is gaining much attention. In this context, genetic basis of the comprehensive phenotyping in ayurveda, the indigenous medicine of Indian subcontinent has drawn much scientific interest. This study reports an innovative application of MR in providing the much needed objective parameters for some of the phenotyping indices. Interestingly, the results show that the phenotypes mentioned in ayurveda as being predisposed to diabetes are found to not only have increased localised fat deposition (abdomen and thigh) (measured by MRI) and triglyceride levels but also lower insulin sensitivity. |
| 3875 | Computer #40 |
High resolution imaging of pelvic lymph nodes at 7 Tesla |
1Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, Netherlands, 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany |
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MRI of the pelvis at a high spatial resolution has potential to assess lymph node status in oncological diseases. We propose to use spectrally selective 3D gradient echo imaging in combination with TIAMO at 7 Tesla to improve upon spatial resolution using the SNR increase that ultra high field MRI provides. The method is shown to robustly obtain homogeneous, large FOV body imaging of the pelvic lymph nodes with a spatial resolution of 0.66x0.66x0.66 mm3, both for T2* weighted as well as lipid selective imaging. |
| 3876 | Computer #41 |
Development of Relaxometry Methods and Hardware for Routine Determination of Volume Status: Dialysis Pilot Study |
1Health Sciences and Technology (HST), MIT, Cambridge, MA, United States, 2Division of Nephrology, Massachusetts General Hospital, Boston, MA, United States, 3Materials Science and Enginering, MIT, Cambridge, MA, United States |
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Incorrect assessment of clinical volume status leads to increased mortality and healthcare costs yet there are no accurate, non-invasive, and quantitative methods to assess this health metric. We evaluated the ability of a portable NMR sensor and relaxometry techniques to detect fluid changes in hemodialysis (HD) patients during the course of HD treatment. There was a significant difference between relaxation values of HD patients compared to healthy subjects. |
| 3877 | Computer #42 |
19F ZTE MR Imaging of 19F labeled calcium phosphate cement at 11.7T |
1Radiology, Radboud University Medical Centre, Nijmegen, Netherlands, 2Biomaterials, Radboud University Medical Centre, Nijmegen, Netherlands, 3Tumor Immunology, Radboud University Medical Centre, Nijmegen, Netherlands |
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To enhance the MR image contrast of calcium phosphate cement (CPC) to bone, it was tagged with a 19F loaded nanoparticle as a contrast agent. 19F zero echo time (ZTE) MRI was applied for the first time for 19F imaging of this CPC in bone at 11.7T. The T1 and T2* relaxation times of the 19F nanoparticles were measured for optimal settings of 19F ZTE MRI. We demonstrate overlaid 1H+19F ZTE images of in vitro and ex vivo CPC/bone samples with hyperintense 19F signals allowing a qualitative and quantitative evaluation of these samples. |
| 3878 | Computer #43 |
Reproducibility of whole body ADC in a non-optimized multi-centre trial: Effectiveness of normalisation method |
1Imaging, University College Hospital, London, United Kingdom, 2Centre for Medical Imaging, University College London, London, United Kingdom, 3Medical Physics and Biomedical Engineering, University College Hospital, London, United Kingdom, 4Clinical Physics, Institute of Nuclear Medicine, University College Hospital, London, United Kingdom, 5NIHR, National Institute for Health Research, London, United Kingdom |
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Diffusion-Weighted (DW) MRI can be used as a quantitative tool but there is limited data documenting accuracy and reproducibility on different MRI scanners with non-identical protocols. We investigated the variation in ADC measurements in normal tissue in datasets acquired as part of a pragmatic multicentre study of whole body MRI cancer and tested the impact of normalisation methods. We found large variations in ADC within both the same platform, and between different MRI platforms. Normalisation had limited benefit and only for one platform. Fat suppression seemed to be the predominant driver of variation particular in tissues outside the brain. |
| 3879 | Computer #44 |
Abdominal FASE-DWI |
1Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan, 2Radiology, Kobe University Hospital, Kobe, Japan, 3Toshiba Medical Systems Co., Otawara, Japan, 4Radiology, Kobe University Graduate School of Medicine, Kobe, Japan |
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To reduce distortion on abdominal EPI-DWI, we developed Fast Advanced Spin Echo (FASE)-DWI for abdominal 3T imaging. We found FASE-DWI can provide additional diagnostic information in evaluation of various abdominal diseases and be used as an alternative to EPI-DWI. |
| 3880 | Computer #45 |
Deep Learning of MR Imaging Patterns in Prostate Cancer |
1UCLA, Los Angeles, CA, United States |
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This demonstrates the feasibility of using Deep Learning to characterize prostate cancer lesions in an automatic fashion. The translation and development of this method into a decision support tool may provide more objective criteria for clinicians during diagnosis. |
| 3881 | Computer #46 |
Can Lack of Marked Restricted Diffusion Downgrade the PI-RADS Score? |
1Radiology, Loyola University Medical Center, Maywood, IL, United States |
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~ Retrospective evaluation of the impact of DWI on PI-RADS scoring of TZ lesions. A blinded radiologist evaluates lesions based on only the DWI sequence and again only on the T2 TSE sequence, in separate occurrences, in patients who underwent targeted biopsy. New PI-RADS scores are given for each of the lesions. The given scores are then correlated with their corresponding Gleason scores. Of the 55 lesions studied, the DWI score downgraded four lesions from a higher T2 score. DWI could play a role in evaluation of TZ lesions, however our data lacked statistical significance. |
| 3882 | Computer #47 |
Effect of Prostate Deformity Due to Endorectal coil on Targeting Outcomes |
1Radiology, Loyola University Medical Center, Maywood, IL, United States, 2Stritch School of Medicine, Maywood, IL, United States, 3Urology, Loyola University Medical Center, Maywood, IL, United States |
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The method of using an endorectal coil in a Prostate Magnetic Resonance Imaging has been an area of debate between radiologists for some time now, with a majority of research projects done to compare this method with the use of phased array coils. In this retrospective project our main objective is to identify if the temporary deforming effects caused by the use of the endorectal coil in a Prostate Magnetic Resonance Imaging (MRI) procedure may affect biopsy targeting. We will collect the dimensions measured by the MRI and compare it to the dimensions measured using the Transrectal Ultrasound procedure (TRUS). |
| 3883 | Computer #48 |
Synthesized versus acquired high b-value (1200 s/mm2) diffusion-weighted magnetic resonance imaging for detection of peripheral zone lesions in the prostate using PI-RADS version 2 |
1Radiology, Stanford University, Palo Alto, CA, United States |
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Greater diffusion weighting is generally thought to increase performance of MRI for prostate cancer detection. We compared acquired high b-value (1200 s/mm2) diffusion-weighted MRI against b-1200 images synthesized from b ≤ 800 acquisitions for detection of peripheral zone lesions in the prostate for 50 consecutive patients undergoing prostate MRI and biopsy using two blinded independent readers. Although subjective image quality was rated slightly but significantly worse for synthesized DWI compared to acquired DWI images, no significant difference in detection of peripheral zone lesions, PI-RADS version 2 lesion categorization, or confidence scores of interpretation were observed. |
| Exhibition Hall | Wednesday, May 11, 2016: 13:30 - 14:30 |
| 3884 | Computer #49 |
Clinical application of susceptibility-weighted MR sequences in the female pelvis |
1Department of Radiology, University of Tokushima, Tokushima, Japan, 2Department of Radiological Technology, Tokushima Bunri University, Sanuki, Japan |
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Susceptibility-weighted (SW) magnetic resonance (MR) sequences have exquisite sensitivity to the blood products within various gynecologic pathologies, and may provide helpful information for the differential diagnosis. In this exhibit we demonstrate the role of SW sequences in diagnosing various pathologies in the female pelvis such as hemorrhagic cysts (endometrioma vs non-endometriotic cyst), extra-ovarian endometriosis and adenomyosis, gestation-associated lesions (ectopic pregnancy and retained products of conception), red degeneration of uterine leiomyoma, high-grade malignancy such as uterine sarcomas with hemorrhagic necrosis, and ovarian torsion. |
| 3885 | Computer #50 |
Assessment of metabolism in the placenta by hyperpolarized MRI |
1MRI Research Centre, Aarhus University Hospital, Aarhus N, Denmark, 2Department of Clinical Medicine, Aarhus University Hospital, Aarhus N, Denmark, 3Department of Obstetrics and Gynaecology, Aarhus University Hospital, Aarhus N, Denmark |
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Glucose is the main energy source for the placenta and the fetus and is essential for normal growth and development of the fetus. It has previously been shown that the placenta itself consumes about half of the glucose supplied, metabolizing a great amount to lactate. Hyperpolarized Magnetic Resonance Imaging (MRI) is a novel non-harmful method for monitoring metabolic processes in tissues in real time. We evaluate the metabolism of [1-13C]-pyruvate in the placenta and fetus in a novel pregnancy rodent model by the use of hyperpolarized MRI. |
| 3886 | Computer #51 |
Evaluation of retained products of conception by arterial spin labeling-MRI: Clinical feasibility and initial results |
1Department of Radiology, University of Fukui, Eiheiji, Japan, 2Department of Medical Imaging, Kumamoto University, Kumamoto, Japan, 3Radiological Center, University of Fukui Hospital, Eiheiji, Japan, 4Global MR Applications and Workflow, GE Healthcare Japan Corporation, Hino, Japan, 5Department of Obstetrics and Gynecology, University of Fukui, Eiheiji, Japan |
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In this study, arterial spin-labeling (ASL)-MRI was used to evaluate the vascularity of retained products of conception (RPOCs). In 5 of 7 cases, high signals on ASL-MRI were observed, and therapeutic response could be evaluated by ASL-MRI. However, these findings of ASL-MRI were not completely identical to those of other conventional imaging modalities, such as dynamic contrast-enhanced MRI and Doppler-US. ASL-MRI is clinically feasible and can be used to assess therapeutic response. Although its clinical advantages over conventional imaging need to be evaluated, ASL-MRI has clinical potential for non-invasive assessment of RPOCs. |
| 3887 | Computer #52 |
Diffusion tensor imaging and fiber tractography in evaluation of the levator ani muscle change in pelvic organ prolapse patients |
1Department of Radiology,Tianjin First Center Clinical College, Tianjin Medical University, Tianjin, Tianjin, China, People's Republic of, 2Department of Radiology, Tianjin First Center Clinical College, Tianjin Medical University, Tianjin, Tianjin, China, People's Republic of, 3Philips Healthcare, Beijing, China, beijing, China, People's Republic of, 4Department of Radiology, Tianjin First Center Hospital, Tianjin, China, Tianjin, China, People's Republic of |
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Levator ani muscle(LAM) dysfunction may cause pelvic organ prolapse(POP). DTI and fiber tracking was used to display the general morphology and microstructure changes of LAM in POP patients. We compared the FA, ADC values of pelvic floor muscles and fiber bundles shape between normal and prolapse group in this study. The results showed that the FA values of LAM muscle in prolapse group were lower than that of control and ADC values were opposite. DTI can realize the assessment of the status of LAM in patients with POP and guide the choice of operation methods. |
| 3888 | Computer #53 |
A reasoned approach to explore single shot FSE acquisition for fetal MRI |
1Department of Biomedical Engineering, King's College London, London, United Kingdom, 2Centre for the Developing Brain, King's College London, London, United Kingdom |
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Fetal MRI is a growing field but it is still far from being a standard examination and setting up a protocol demands careful optimization. Here we explore some factors to consider when choosing an appropriate slice acquisition order pattern to mitigate the effect of crosstalk between temporally consecutive slices and the partial saturation from the excitation of the adjacent slice, while taking moderate range of fetal motion into account. |
| 3889 | Computer #54 |
The feasibility of red bone marrow segmentation based on MR Dixon only. |
1UMC Utrecht, Utrecht, Netherlands |
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In this study a (semi-)automatic tool for red bone marrow segmentation in the pelvis was developed. The tool is solely based on MR Dixon imaging. It is intended for the dose planning for radiotherapy with the hematologic active bone marrow sparing. The optimization and validation of the tool was performed by means of FDG-PET scans of nine cervical cancer patients. |
| 3890 | Computer #55 |
HOW TO MAP PELVIC AUTONOMIC NERVES: VALUE OF A 3D HIGH-RESOLUTION MR NEUROGRAPHY SEQUENCE |
1IHU Strasbourg, Institute of image-guided surgery, Strasbourg, France, 2IRCAD, Research Institute Against Digestive Cancer, Strasbourg, France |
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The goal of this study was to investigate the value of a 3D high-resolution sequence with a particular contrast to visualize and delineate pelvic autonomic nerves in a healthy volunteer. Through segmented images and the corresponding 3D reconstruction, we show that our method offers interesting results for the delineation of the hypogastric plexus and the pudendal nerves that are frequently impacted by pelvic surgery. These results are promising for individualized preoperative mapping of autonomic innervation and could provide a valuable support to guide surgeons during interventions when combined with augmented reality. |
| 3891 | Computer #56 |
Feasibility of Fetal Fat Volume Assessment using 3D Water-Fat MRI |
1Medical Biophysics, Western University, London, ON, Canada, 2Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, 3Division of Maternal, Fetal and Newborn Health, Children's Health Research Institute, London, ON, Canada, 4Obstetrics and Gynecology, Western University, London, ON, Canada |
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Conventional ultrasound techniques perform adequately in assessment of fetal size in obese mothers but fail to identify the fetus that is chronically stressed inside the womb. A reliable MRI measurement of fetal fat volume and distribution would therefore be a powerful tool in the assessment of fetal condition. Using a 3D LAVA-Flex sequence during maternal breath hold, fat signal fraction images were generated to measure the fat volume of the fetus, while correcting for partial volume effects. 3D water-fat MRI was found to provide a reliable measurement of fetal fat volumes that could be used to assess size and growth. |
| 3892 | Computer #57 |
A pre-processing pipeline for bias field correction and rigid and elastic motion compensation in Placental-Fetal BOLD MRI |
1Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States, 2Madrid-MIT M+Vision Consortium in RLE, Massachusetts Institute of Technology, Cambridge, MA, United States, 3Maternal and Fetal Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States, 4Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 5Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, 6Computer Science and Artificial Intelligence Laboratory (CSAIL), Massachusetts Institute of Technology, Cambridge, MA, United States, 7Medical Image Analysis and Biometry Laboratory, Universidad Rey Juan Carlos, Madrid, Spain |
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Abnormal oxygen transport through the placenta is thought to be a major etiologic factor in intrauterine growth restriction (IUGR). Blood-oxygen-level-dependent (BOLD) magnetic resonance imaging (MRI) with oxygen exposure is a non-invasive technique that can estimate oxygenation changes in specific organs. However, applying this technique to placentae and fetal organs can be challenging due to non-uniform signal and unpredictable fetal and maternal motion. This study presents a preprocessing pipeline to mitigate signal non-uniformities and motion, to enable automated regional analysis of placenta and fetal body for BOLD MRI studies. |
| 3893 | Computer #58 |
In Vitro and in Vivo MR measurement of fetal blood oxygen saturation |
1Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 2Philips Medical Systems, Hamburg, Germany, 3Department of Obstetrics and Fetal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany |
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Intrauterine growth restriction is associated with a decreased oxygen availability. In clinical practice, indicators such as Doppler changes of the ductus venosus and umbilical artery are measured and a direct measurement using MR oximetry would be desirable. The relationship between T2 relaxation time and oxygen saturation (sO2) is determined in in-vitro fetal blood samples and the feasibility of a noninvasively determination of fetal sO2 is evaluated. The calculated fetal sO2 highly correlated with measured sO2 values and determined parameters were successfully evaluated in-vivo in the left fetal ventricle. |
| 3894 | Computer #59 |
Real-time Chest MRI within the Neonatal Intensive Care Unit |
1Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States |
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The presented work investigates a real-time imaging approach to chest MRI on a 21.8cm bore scanner dedicated for neonatal examination within the neonatal intensive care unit (NICU). This approach is based on the development of a 10-channel small coil array, a fast imaging pulse sequence, and an iterative image reconstruction algorithm. It is experimentally demonstrated that real-time imaging can provide high-quality cardiac and pulmonary images for improved clinical diagnosis in premature babies within the NICU. |
| 3895 | Computer #60 |
Shortened Fatty Acid Chains in Cervical Cancer using 1H MRSI at 7T |
1Imaging Division, University Medical Center Utrecht, Utrecht, Netherlands, 2Gynaecological oncology, University Medical Center Utrecht, Utrecht, Netherlands, 3Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
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The feasibility of MRSI at 7T to image fatty acid composition in cervical cancer patients was investigated . A relatively high 2.1 ppm fatty acid signal was only observed in tumor tissue. Tumor free cervix showed predominantly the 1.3 ppm lipids signal. Metabolic maps of the 2.1 ppm fatty acid showed heterogeneity within the tumor, which coincided with a hyper-intense area within the T2-weighted image, that may indicate local necrosis. |
| 3896 | Computer #61 |
First Trimester Alcohol Exposure Alters Placental Perfusion and Fetal Oxygen Transport in a Pregnant Non-Human Primate Model |
1Oregon Health & Science University, Portland, OR, United States, 2Oregon National Primate Research Center, Beaverton, OR, United States |
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Alcohol consumption in pregnancy adversely affects fetal growth and development, likely secondary to altered placental perfusion resulting in decreased fetal oxygen availability. We developed a novel MRI technique that allows in-vivo assessment and correlation of placental perfusion and oxygenation. Our study demonstrated reduced placental perfusion and oxygenation with first trimester ethanol exposure in a pregnant nonhuman primate model using a novel MRI method and Doppler ultrasound. Impaired fetal growth was also observed. These findings suggest that discontinuation of alcohol consumption after the first trimester is associated with decreased placental perfusion and oxygenation subsequently affecting fetal growth and development. |
| 3897 | Computer #62 |
Quantitative evaluations of placental function using Half-Fourier acquisition single-shot turbo spin-echo comparing with T2-relaxation time. |
1Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan, 2Gynecology and Obstetrics, Graduate School of Medicine, Kyoto University, Kyoto, Japan, 3Diagnostic Pathology, Graduate School of Medicine, Kyoto University, Kyoto, Japan |
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Half-Fourier acquisition single-shot turbo spin-echo (HASTE) imaging is now widely used for placental and fetal imaging due to its rapidity and its low sensitivity to fetal movement. We aimed to investigate the index of placental dysfunction using HASTE imaging by comparing T2-relaxation time, which is known to be one of the noninvasive biomarkers for IUGR. The placental SIR to the maternal psoas muscle (SIRpl/psoas muscle) showed significant correlation with placental T2 relaxation time. There was possibility that SIRpl/psoas muscle may have relation with fetal well-beings. |
| 3898 | Computer #63 |
MRI Features of Placenta Percreta: Evaluation of the Features for 46 Patients Using Surgical and Histopathological Correlations |
1Shandong University, Jinan, China, People's Republic of, 2Shangdong Medical Imaging Research Institute, Jinan, China, People's Republic of, 3MR Collaborations NE Asia, Siemens Healthcare, Beijing, China, People's Republic of |
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The objective of the study was to identify valuable features to distinguish placenta percreta from placenta accreta and increta by retrospectively reviewing placenta MRI together with clinical findings for 46 patients diagnosed with invasive placenta. Single-shot turbo spin echo and true fast-imaging with steady-state precession sequence were included in the MR exam protocol. Two experienced radiologists evaluated seven MRI features using surgical and histopathological correlations. The features of bulging placenta including cyrtoid outline, marked placental heterogeneity and signs of placental protrusion are useful to distinguish placenta percreta from placenta accreta and increta. The wall of urinary bladder with nodular protrusion is indicative of urinary bladder involvement. |
| 3899 | Computer #64 |
Diffusional Kurtosis Imaging of Kidneys in Children with Chronic Kidney Disease: Initial Experience |
1Department of Radiology, Beijing Children’s Hospital Affiliated to Capital Medical University, Beijing, China, People's Republic of, 2GE Healthcare, MR Research China, Beijing, China, People's Republic of, 3Department of Nephrology, Beijing Children’s Hospital Affiliated to Capital Medical University, Beijing, China, People's Republic of |
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To evaluate the feasibility of DKI in assessment of renal functions in children with chronic kidney disease (CKD). Materials and Methods: This study was IRB approved and informed consent was obtained. Fifteen pediatric patients with CKD and nine children without renal diseases underwent DKI of kidneys. Maps of fractional anisotropy (FA), mean diffusivity (MD), mean kurtosis (MK), radial kurtosis (K⊥) and axial kurtosis (K//) were produced. Results: There is a significant difference of kurtosis metrics and FA of renal medulla compared to those of renal cortex in both the control group and CKD group. FA, MD, K⊥ and MK values of both the cortex and medulla of kidney have significant differences between patients with CKD and control group. Conclusion: DKI could be a useful tool in the evaluation of renal function in children with CKD. |
| 3900 | Computer #65 |
Estimation of Oxygen Saturation in Renal Blood Using Intravoxel Incoherent Motion (IVIM) Imaging by FLAIR DWI |
1Radiology, Tohoku University Hospital, Sendai, Japan, 2Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Japan, 3Graduate School of Medicine, Tohoku University, Sendai, Japan |
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We aimed to apply IVIM imaging to estimate blood oxygen saturation in kidneys with extraction of glomerular filtrate fraction by using fluid-attenuated inversion recovery diffusion-weighted imaging (FLAIR DWI). A 3-compartment model (renal tissue, blood and water) was considered for the estimation. Combination of DWI and FLAIR DWI provided renal tissue T1. Images were acquired with two TEs to provide blood T2 which allows for estimation of blood oxygen saturation. Our model generated estimation of glomerular filtrate fraction, blood R2 and blood oxygen saturation. FLAIR DWI has a potential to estimate blood oxygen saturation with extracting glomerular filtrates fractions in kidneys. |
| 3901
|
Computer #66 |
Renal ischemia and reperfusion assessment with 3D hyperpolarized 13C urea |
1Clinical medicine, Aarhus university, Aarhus C, Denmark, 2MR Research Centre, institute of clinical medicine, Aarhus C, Denmark, 3Institute of clinical medicine, Aarhus C, Denmark, 4institute of clinical medicine, Aarhus C, Denmark, 5MR Research Centre, Institute of clinical medicine, Aarhus C, Denmark |
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Renal homeostasis is determined by the active transport of water and waste products, and the key to this is the active intra-renal transport of ions, creating the needed osmotic gradient. The maintenance of this cortico-medullary ion gradient is believed to be a measurement of kidney function. We investigated 3D hyperpolarized 13C,15N-urea for mapping of this intra-renal gradient in a unilateral ischemic reperfusion renal rat model. A 3D balanced steady state sequence with an isotropic 1.25 mm resolution was used to image renal ischemic reperfusion injury. We revealed a significant reduction in the intra-renal ion gradient in the ischemic kidney. |
| 3902 | Computer #67 |
Lactate dehydrogenase activity, a novel renal cortical imaging bio-marker of tubular injury. |
1institute of clinical medicine, Aarhus C, Denmark |
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Renal I/R-I is a leading cause of AKI in several disease states; there is a current lack of precise methods to directly assess cortical tubular injury. In the present study, we investigated the in situ alterations of metabolic conversion of pyruvate to lactate in a unilateral I/R-I rat model using [1-13C]pyruvate magnetic resonance. A significantly reduced lactate-to-pyruvate ratio of 25% as compared to control was found in the I/R-I kidney, concomitant with a reduced LDH activity, which was specific for the I/R-I kidney. The lowered lactate-to-pyruvate ratio and LDH activity strongly correlated with general tissue damage. |
| 3903 | Computer #68 |
Antioxidant treatment attenuates renal lactate production in diabetic nephropathy |
1Department of Clinical Medicine, MR-Research Centre, Aarhus University, Aarhus, Denmark, 2Department of Endocrinology and Internal Medicine and Department of Clinical Medicine, Aarhus University, Aarhus, Denmark, 3The Danish Diabetes Academy, Odense, Denmark, 4Department of Electrical Engineering, Technical University of Denmark, Kgs Lyngby, Denmark, 5Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden |
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Early diabetic nephropathy (DN) disease progression is notoriously difficult to detect and quantify before substantial histological damage has occurred. Recently, hyperpolarized [1-13C]pyruvate has demonstrated increased lactate production, implying increased lactate dehydrogenase activity, in the kidney early after the onset of diabetes as a consequence of increased nicotinamide adenine dinucleotide (NADH) substrate availability due to elevated flux through the polyol pathway. Here we investigated whether this deranged metabolic profile can be reversed by antioxidant treatment targeting the pseudohypoxic condition. |
| 3904 | Computer #69 |
Quantitative Estimation of Renal Blood PO2 using BOLD MRI in Rat Kidneys. |
1Northwestern University, Evanston, IL, United States, 2University of Utah, Salt Lake City, UT, United States, 3NorthShore University HealthSystem, Evanston, IL, United States |
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Blood oxygen level dependent (BOLD) MRI measurements generally use the transverse relaxation rate, R2*, as an indirect measure of oxygenation. While it has been shown to be related to tissue PO2, and sensitive to changes in oxygenation induced by pharmaceutical maneuvers, R2* is sensitive to other physiological parameters (e.g. hydration, hematocrit, blood perfusion) and hence not a great measure of the physiologically parameters of interest. In this study, we apply a quantitative model to BOLD MRI measurements in rodent kidneys and derive regional values for hemoglobin saturation and blood PO2. The MRI derived blood PO2 measurements are in agreement with literature. |
| 3905 | Computer #70 |
Renal Ischemia/Reperfusion necrosis monitoring with hyperpolarized fumarate |
1institute of clinical medicine, Aarhus C, Denmark, 2Lyngby, Denmark |
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Renal I/R-I is a leading cause of AKI in several disease states; there is a current lack of precise methods to directly assess cortical tubular injury. In the present study, we investigated the in situ conversion of fumarate to malate in a unilateral Ischemia/reperfusion model, which is correlated with renal tubular necrosis. We saw a strong binary [1,4-13C2]malate signal in the I/R-I kidney and a strong binary [1,4-13C2]fumarate signal in the healthy CL kidney. This was correlated with histological examinations indication renal tubular necrosis. As well as compartmentalized fumarase activity specific for I/R-I. |
| 3906 | Computer #71 |
Renal [1-13C]-acetate turnover mapping with hyperpolarized MRI |
1MRI Research Centre, Aarhus University Hospital, Aarhus N, Denmark, 2Institute of Medical Engineering, Technische Universität München, Munich, Germany, 3GE Global Research, Munich, Germany |
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Positron Emission Tomography (PET) using carbon-11 acetate has previously been used to reveal the oxidative metabolism in the kidneys. It has been found that renal carbon-11 acetate turnover measured by PET was significantly correlated with renal oxygen consumption and tubular sodium reabsorption measured by an invasive approach. Hyperpolarized MRI is an alternative method to obtain similar intracellular measures of acetate, and the aim of this study was therefore to evaluate the rate constants of hyperpolarized [1-13C]-acetate in rat kidneys. The intrarenal oxygen level was altered by diuretics, and measures of acetate rate constants were calculated before and after injection of furosemide. |
| 3907 | Computer #72 |
Exploring Intratumoral Heterogeneity of Lipid Metabolism in Clear Cell Renal Cell Carcinoma with Dixon-based MRI |
1Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 2Pathology, UT Southwestern Medical Center, Dallas, TX, United States, 3Urology, UT Southwestern Medical Center, Dallas, TX, United States, 4Kidney Cancer Program, Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, TX, United States, 5Molecular Genetics, UT Southwestern Medical Center, Dallas, TX, United States, 6Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 7Philips Medical Systems, Cleveland, OH, United States, 8Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States, 9Developmental Biology, UT Southwestern Medical Center, Dallas, TX, United States |
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We investigated the correlation between in vivo fat fraction (FF) measurements by Dixon-based MRI in clear cell renal cell carcinoma (ccRCC) and both intracellular fat accumulation at histopathology and lipidomic profile in the same tumor by mass spectrometry. Quantitative targeted fat fraction measures were obtained from representative areas within each tumor and correlated with the percentage of cells containing fat in fresh tissue samples from the same location of the tumor. Lipidomic analysis of additional tissue samples was performed. Quantitative FF measures correlated with lipid accumulation in ccRCC and provide a tool for assessing heterogeneous metabolic pathways in these tumors. |
| Exhibition Hall | Wednesday, May 11, 2016: 13:30 - 14:30 |
| 3908 | Computer #73 |
Effect of a two week hyper energetic matched high carbohydrate vs high fat diet on hepatic fat stores and metabolic blood markers: A 1H MRS Study |
1NIHR Nottingham Digestive Diseases Research Unit, University of Nottingham, Nottingham, United Kingdom, 2Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, 3School of Life Sciences, University of Nottingham, Nottingham, United Kingdom |
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This study used 1H MRS to investigate the effects of a two week hyper-energetic 25% excess overfeeding diet of either high carbohydrate or high fat content on liver fat in 20 healthy overweight volunteers. Significant increases were found in whole group and in the high carbohydrate group, with smaller non-significant increases observed in the high fat group. Other blood measures and body fat were investigated also. |
| 3909 | Computer #74 |
Effects of lifestyle intervention on liver volume, intrahepatic fat and body weight: What are the metabolic benefits? |
1Department of Diagnostic and Interventional Radiology, University Hospital of Tübingen, Tübingen, Germany, 2Department of Endocrinology, Metabolism, Clinical Chemistry, Nephrology and Angiology, University Hospital of Tübingen, Tübingen, Germany, 3Department of Diagnostic and Interventional Radiology, Section on Experimental Radiology, University Hospital of Tübingen, Tübingen, Germany, 4Institute for Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University of Tübingen (Paul Langerhans Institute Tübingen), Tübingen, Germany, 5German Center for Diabetes Research (DZD), Tübingen, Germany |
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Using MRI, the quantification of liver volume and identification of several compartments of adipose tissue with varying impact on metabolism is reliably possible. 1H-MRS is established as non-invasive ‘gold standard’ to quantify the amount of ectopic lipids in the liver. Lifestyle interventions show differing effects on the compartments of physiological and ectopic lipids. Caloric restriction during lifestyle interventions leads to reduced liver volume, caused by a decrease of intrahepatic lipids (IHL). The decrease of IHL shows gender specific effects on liver enzymes, primarily resulting in lowered gamma-glutamyl transferase in females and lowered alanine transaminase in males. Only in females, the decrease of IHL seems to influence the systemic low-grade inflammation positively. |
| 3910 | Computer #75 |
Racial Differences in Visceral Fat and Hepatic Fat Fraction in Men with HIV, Hepatitis C, or HIV/Hepatitis C Co-infection |
1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Northern California Institute for Research and Education, San Francisco, CA, United States, 3University of California, San Francisco, San Francisco, CA, United States, 4Department of VA Medical Center, San Francisco, CA, United States |
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The purpose of this work is to compare differences in visceral fat volume (by IDEAL imaging) and hepatic fat fraction (FF) (by single-voxel MRS) between African American (AA) and Caucasian (CA) men with HIV, HCV, or co-infection (HIV/HCV) against an age-matched control population. We observe AA men to have a trend towards less MR-measured visceral fat and hepatic FF than CA men in a control population. This difference was enhanced and was significant in the HIV population, while there was no observable difference in the HCV or HIV/HCV populations, indicating a need to consider both race and disease status prior to interpretation of visceral or hepatic FF findings. |
| 3911 | Computer #76 |
Portosystemic shunts in C57BL/6J mice are associated with high levels of hepatic lipids and glucose intolerance |
1Laboratory of Functional and Metabolic Imaging (LIFMET), Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, 3Department of Radiology, University of Geneva (UNIGE), Geneva, Switzerland, 4Department of Radiology, University of Lausanne (Unil), Lausanne, Switzerland |
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C57BL/6J mice widely used in preclinical research exhibit sporadic congenital portosystemic shunts that prevent normal delivery of nutrients and hormones to the liver. We used MRI to diagnose portosystemic shunts in mice, and furthermore showed that their hepatic lipid content, as determined by 1H-MRS in vivo is abnormally high. Also, compared with healthy cage mates, mice with portosystemic shunts displayed lower fasting glucose and insulin levels, with a less efficient glucose clearance after a glucose gavage. Hence, hepatic metabolism is significantly altered in mice with portosystemic shunts with consequences to whole-body glucose homeostasis. |
| 3912 | Computer #77 |
Quantification of liver metabolites in a rat model of high-fat-diet-induced nonalcoholic fatty liver disease with 1H MRS using internal standard method |
1Department of Biomedical Engineering, and Research Institute of Biomedical Engineering, The Catholic University of Korea College of Medicine, Seoul, Seoul, Korea, Republic of |
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Our results of noninvasive in vivo proton magnetic resonance spectroscopy are based on accurate monitoring of the changes in lipid content, which were verified using the data on saturated fatty acids and unsaturated fatty acids. |
| 3913 | Computer #78 |
Subcutaneous fat unsaturation is negatively associated with liver fat fraction |
1Department of Diagnostic and Interventional Radiology, Technische Universitaet Muenchen, Munich, Germany, 2Else Kroener Fresenius Center for Nutritional Medicine, Technische Universitaet Muenchen, Munich, Germany, 3Philips Healthcare, Hamburg, Germany |
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Obesity, metabolic syndrome and diabetes are public health problems leading to increased morbidity and mortality. The present study performed fatty acid profiling of the abdominal adipose tissue by using MRS and found inverse correlations between SAT and liver fat fraction and regional distribution of adipose tissue (i.e. SAT and VAT volumes) assessed by chemical shift encoding-based water-fat MRI. This study allowed interesting insights into the obese phenotype and the reported findings may play an important role to identify different obese phenotypes, e.g. metabolically benign and insulin-resistant obese, which has clinical implications on patient treatment. |
| 3914 | Computer #79 |
Manganese-Enhanced Magnetic Resonance Imaging of Pancreatic Function in Mice |
1Dept of Cell Physiology and metabolism, University of Geneva, Geneva, Switzerland, 2Dept of Biomedical Engineering, Imperial College, London, United Kingdom, 3Animal Imaging and Technology CIBM-AIT, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 4Laboratory of functional and metabolic imaging LIFMET, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 5Radiology, University of Lausanne, Lausanne, Switzerland, 6Radiology, University of Geneva, Geneva, Switzerland |
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Magnetic Resonance Imaging (MRI) at high magnetic field, with the help of manganese, a calcium analogue and a T1 shortening contrast agent in MRI, could be beneficial for imaging murine pancreatic function. |
| 3915 | Computer #80 |
Automated Multi-Atlas Segmentation of Suspected Brown Adipose Tissue from Water-Fat MRI: Initial Evaluation |
1Department of Radiology, Uppsala University, Uppsala, Sweden, 2Department of Information Technology, Uppsala University, Uppsala, Sweden, 3Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden, 4Children Obesity Clinic, Uppsala University Hospital, Uppsala, Sweden, 5Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden, 6Department of Paediatrics, Division of Paediatric Gastroenterology, Hepatology and Nutrition, Paracelsus Medical University, Salzburg, Austria, 7Obesity Research Unit, Paracelsus Medical University, Salzburg, Austria, 8Department of Radiology, Paracelsus Medical University, Salzburg, Austria |
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Segmentation of brown adipose tissue (BAT) from water-fat MR images generally requires time-consuming manual delineation. In this work a fully automated method, based on multi-atlas registration, for segmentation of human cervical-supraclavicular adipose tissue (suspected BAT) was evaluated using a semi-automated reference method, based on manual delineation. The presented method shows promising results for automated segmentation that allows time-efficient and objective measurements of BAT in large cohort research studies. |
| 3916 | Computer #81 |
Longitudinal Evaluation of Brown Adipose Tissues in Rats By Multi-Modal Imaging |
1Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, 2Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, Singapore, 3Singapore Institute for Clinical Sciences, Singapore, 4Department of Endocrinology, Tan Tock Seng Hospital, Singapore |
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There are two types of fat tissues, white adipose tissue (WAT) and brown adipose tissue (BAT), which essentially perform opposite functions in whole body energy metabolism. Cold exposure activates adrenergic receptor in the brown adipose tissues, and improve the separation of WAT and BAT. In this study we have evaluated the longitudinal changes of fat fraction (FF), and relaxation times (T2 and T2*) of interscapular brown adipose tissue (BAT) of rats under thermoneutral and short term cold exposure, and validated with histology and UCP1. PET-CT was performed to visualize the activated BAT. |
| 3917 | Computer #82 |
Repeatability and accuracy of a novel, MRI-based, semi-automated analysis method for quantifying abdominal adipose tissue and thigh muscle volumes |
1Department of Radiology, UCSD, San Diego, CA, United States, 2Advanced MR Analytics AB (AMRA), Linkoping, Sweden, 3Center for Medical Image Science and Visualization, Linkoping University, Linkoping, Sweden, 4Department of Biomedical Engineering, Linkoping University, Linkoping, Sweden, 5Department of Medicine and Health, Linkoping University, Linkoping, Sweden, 6Radiology, UCSD, San Diego, CA, United States, 7Computational and Applied Statistics Laboratory (CASL), UCSD, San Diego, CA, United States, 8Department of Medicine, UCSD, San Diego, United Kingdom |
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Current MRI methods to estimate body tissue compartment volumes rely on manual segmentation, which is laborious, expensive, not widely available outside specialized centers, and not standardized. To address these concerns, a novel, semi-automated image analysis method has been developed. Image acquisition takes about six minutes, and uses widely available MRI pulse sequences. We found that this method permits comprehensive body compartment analysis and provides high repeatability and accuracy. Current and future clinical and drug development studies may benefit from this methodology, as may clinical settings where monitoring change in these measures is desired. |
| 3918 | Computer #83 |
A Preliminary Study on Brown Adipose Tissue Detection Using PET/MR |
1Physics, UNC Chapel Hill, Chapel Hill, NC, United States, 2Biomedical Research Imaging Center, UNC Chapel Hill, Chapel Hill, NC, United States, 3Biomedical Research Imaging Center, Chapel Hill, NC, United States, 4Department of Exercise and Sports Science, UNC Chapel Hill, Chapel Hill, NC, United States, 5Department of Emergency Medicine, UNC Chapel Hill, Chapel Hill, NC, United States |
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A hybrid PET-MR scanner was used to compare proposed MR techniques to the FDG PET gold standard for brown adipose tissue detection. The subjects were cooled inside of the magnet while PET and MR fat fraction and BOLD techniques were obtained. It was found that MR techniques alone are not sufficient to accurately predict BAT volume but can be used to increase along side PET to increase BAT specificity. |
| 3919 | Computer #84 |
The effect of flip-angle on body composition using calibrated water-fat MRI. |
1Department of Biomedical Engineering, Linköping University, Linköping, Sweden, 2Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden, 3Department of Medical and Health Sciences (IMH), Linköping University, Linköping, Sweden, 4Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden |
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This study tested how the flip angle affects body composition analysis by MRI, if adipose tissue is used as an internal intensity reference. Whole-body water-fat images with flip angle 5° and 10° were collected from 29 women in an ongoing study. The images were calibrated based on the adipose tissue signal and whole-body total adipose, lean and soft tissue volumes were measured. A mean difference of 0.29 L, or 0.90 % of the average volume, and a coefficient of variation of 0.40 % was observed for adipose tissue. |
| 3920 | Computer #85 |
Infant size-for-gestational age, obesity and ethnicity are associated with intramyocellular lipid content in Asian preschoolers |
1Singapore Institute for Clinical Sciences, A*STAR, Singapore, 2Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 3Singapore BioImaging Consortium, A*STAR, Singapore, 4Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 5Department of Paediatric Endocrinology, KK Women’s and Children’s Hospital, Singapore, 6Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 7Liggins Institute, University of Auckland, Auckland, New Zealand, 8MRC Lifecourse Epidemiology Unit & NIHR Southampton Biomedical Research Centre, University of Southampton & University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom, 9Clinical Nutrition Research Centre, Singapore Institute for Clinical Sciences, A*STAR, Singapore, 10Department of Endocrinology, Tan Tock Seng Hospital, Singapore, 11Department of Diagnostic and Interventional Imaging, KK Women’s and Children’s Hospital, Singapore |
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The goal of this study was to understand the contribution of ethnicity, obesity and early developmental factors on IMCL determined in Asian preschoolers. Prior works on IMCL in children have found IMCL to be positively associated with childhood obesity and maternal hyperglycemia. We show that, while children with higher BMI-for-age have higher IMCL, children born SGA also have higher IMCL at 4.5 years, despite being less obese, and despite having lower maternal BMI and maternal fasting glucose than children born AGA. We also found higher IMCL in 4.5 year-old Indian children than in Chinese and Malay children. |
| 3921 | Computer #86 |
Comparison of abdominal fat volume and fat cell hypertrophy in ex-SGA and AGA Asian preschoolers |
1Singapore Institute for Clinical Sciences, A*STAR, Singapore, 2Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 3Singapore BioImaging Consortium, A*STAR, Singapore, 4Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 5Department of Paediatric Endocrinology, KK Women’s and Children’s Hospital, Singapore, 6Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, 7Liggins Institute, University of Auckland, Auckland, New Zealand, 8MRC Lifecourse Epidemiology Unit & NIHR Southampton Biomedical Research Centre, University of Southampton & University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom, 9Clinical Nutrition Research Centre, Singapore Institute for Clinical Sciences, A*STAR, Singapore, 10Department of Endocrinology, Tan Tock Seng Hospital, Singapore, 11Department of Diagnostic and Interventional Imaging, KK Women’s and Children’s Hospital, Singapore |
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Children born small-for-gestational age (SGA) are at an increased risk of developing diabetes and obesity. In vitro studies have shown higher lipid content in adipocytes differentiated from mesenchymal stem cells obtained from the umbilical cord of SGA neonates compared to appropriate-for-gestational age (AGA) infants. However, validating this in children is difficult as assessment of adipocyte hypertrophy has traditionally necessitated adipose tissue biopsies. In earlier studies, we have shown that hydrolipidic ratio (HLR) determined using MRS is negatively associated with adipocyte hypertrophy. In this work, we examined the size-for-gestational age specific differences in abdominal subcutaneous fat and HLR in Asian preschoolers. |
| 3922 | Computer #87 |
Dietary Fat Content Modulates the Effect of Long-term Exercise on Intramyocellular and Intrahepatic Lipids but not on Weight or Insulin Sensitivity |
1Laboratory of Molecular Imaging, Singapore Bio-Imaging Consortium, BioMedical Sciences, Singapore, Singapore, 2Singapore Instiute for Clinical Sciences, Singapore, Singapore |
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The goal of this study was to investigate how dietary fat intake modulates the effect of long term exercise training on body weight, intrahepatic and intramyocellular lipids (IHL & IMCL), and effect on insulin sensitivity in an animal model of long-term exercise. Long term exercise was found to result in significant elevations in IMCL and IHL under low fat background diet, and significant reductions in IMCL and IHL under a high fat background diet, compared to sedentary diet-matched controls. Dietary fat content did not modulate the effect of exercise on insulin sensitivity. |
| 3923 | Computer #88 |
Longitudinal and Cross-Sectional Assessment of Proton Density Fat Fraction and Metabolic Syndrome in Obese Patients undergoing Weight Loss Surgery |
1Radiology, University of Wisconsin, Madison, WI, United States, 2Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN, United States, 3Radiology, University of California, San Diego, CA, United States, 4Surgery, University of Wisconsin, Madison, WI, United States, 5Surgery, Virginia Commonwealth University, Richmond, VA, United States, 6Medical Physics, University of Wisconsin, Madison, WI, United States, 7Biomedical Engineering, University of Wisconsin, Madison, WI, United States, 8Medicine, University of Wisconsin, Madison, WI, United States, 9Emergency Medicine, University of Wisconsin, Madison, WI, United States |
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The purpose of this work was to determine the relationship between proton density fat fraction (PDFF) and metabolic syndrome (MetS) in obese patients. Patients were recruited for an MRI study 1-2 days prior to weight loss surgery (WLS). A subset of these patients with biopsy confirmed hepatic steatosis were recruited for a second MRI 6 months post WLS. A cut-off PDFF of 7.5% had a sensitivity of 77% and specificity of 80% for predicting MetS prior to undergoing WLS. At 6 months follow-up, patients with confirmed hepatic steatosis had significantly decreased prevalence of MetS (91% to 52%). Additionally, other metabolic, biometric, and imaging (PDFF) markers related to MetS were significantly reduced. |
| 3924 | Computer #89 |
Assessment of Fat Accumulation and Mobilization during obesity and weight-loss Interventions in Rodents |
1Laboratory of Metabolic Imaging, Singapore Bioimaging Consortium, Singapore, Singapore, 2Singapore Institute for Clinical Sciences, Singapore, Singapore |
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Quantification of adipose tissue distribution within the abdomen is fundamental for investigations in obesity and diabetes. Distribution of fat within the body, and its accumulation in the abdominal cavity, exert different physiologic effects based on their anatomical location. Calorie-restriction and exercise interventions improve obesity risk factors. Fat accumulation and mobilization can vary depending on the type and quality of fat in different locations. We have investigated the quantitative changes in fat volumes at different positions in the abdomen in diet induced obese rats. |
| 3925 | Computer #90 |
Longitudinal imaging of interscapular brown adipose tissues in high fat diet induced obese rats |
1Laboratory of Metabolic Imaging, Singapore Bioimaging Consortium, A*STAR, Singapore, 2Singapore Institute for Clinical Sciences, A*STAR, Singapore, 3Fat Metabolism and Stem Cell Group, Singapore Bioimaging Consortium, A*STAR, Singapore |
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Obesity and diabetes are major metabolic disorders associated with dietary intake. Brown adipose tissue (BAT) is major site for adaptive thermogenesis involving uncoupling protein-1. We performed longitudinal imaging of fat fraction (FF) of interscapular BAT in control and high fat diet fed rats under thermoneutral and cold exposure conditions on Wistar rats of 7, 11 and 15 weeks. High fat diet results in increased fat fraction in iBAT. Histology shows increased size of brown adipocytes which may alter BAT function and influence thermogenic potential. UCP1 was upregulated in HFD groups. With cold exposure FF reduced significantly in control and HFD groups. |
| 3926 | Computer #91 |
Quantitative Magnetic Resonance Imaging of Renal Steatosis in Obesity and Type II Diabetes Mellitus |
1Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States, 2Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, 3Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States, 4Clinical Science, University of Texas Southwestern Medical Center, Dallas, TX, United States |
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In this retrospective pilot study, proton-density fat fraction (PDFF) of kidneys was compared in 40 and 29 adult subjects without and with type 2 diabetes mellitus (DM2), respectively. Median PDFF was significantly higher in DM2 (2.18%) than non-DM2 subjects (0.78%), with p=0.0008. Statistically significant correlation was found between renal PDFF and body-mass-index (BMI; r=0.2661, p=0.027). After correcting for age, sex, and BMI, PDFF difference due to DM2 remained statistically significant with p=0.0045. |
| 3927 | Computer #92 |
Multimodal MRI protocol for characterization of fat quantity and composition as well as cardiac parameters in patients with long-chain fatty acid oxidation defects (LCFAOD) |
1Magnetic Resonance Development and Application Center (MRDAC), University Medical Centre, Freiburg, Germany, 2Department of Pediatrics, Adolescent Medicine and Neonatology, University Medical Center, Freiburg, Germany, 3Medical Physics, Department of Radiology, University Medical Center, Freiburg, Germany |
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Deficiency of very-long-chain acyl-CoA dehydrogenase is the most common inherited disorder of mitochondrial β-oxidation of LCFAs with an incidence of about 1:50,000 to 1:100,000 newborns. The clinical phenotype is very heterogeneous, involving organs and tissues that mostly rely on fatty acid β-oxidation for energy production. In order to develop new monitoring and treatment strategies various approaches to characterize such patients are tested. Here a multimodal MR-approach already applied in a pre-clinical setting is transferred to humans within a pilot study. Cardiac MRI is combined with Dixon-fat/water MRI and liver MR-spectroscopy. |
| 3928 | Computer #93 |
ORBITAL FAT VOLUMETRY AND FAT FRACTION MEASUREMENT USING ITERATIVE DECOMPOSITION OF WATER AND FAT WITH ECHO ASYMMETRY AND LEAST-SQUARES ESTIMATION-FAST SPIN ECHO (IDEAL -FSE) |
1Radiology, Chugoku Rosai Hospital, Kure, Japan, 2Clinical radiology, Hiroshima University Hospital, Hiroshima, Japan, 3Diagnostic Radiology, Hiroshima University Hospital, Hiroshima, Japan |
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We believe that the quantitative evaluation of orbital fat proliferation and edema is useful for diagnosing and monitoring Graves’ ophthalmopathy. We demonstrate the feasibility of orbital fat volumetry and fat fraction measurement using iterative decomposition of water and fat with echo asymmetry and least-squares estimation-fast spin echo (IDEAL-FSE) and analyze preliminary data from healthy adults. |
| 3929
|
Computer #94 |
T2* and T1 assessment of abdominal tissue response to graded hypoxia and hypercapnia using a controlled gas mixing circuit for small animals |
1Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada, 2Physiology & Experimental Medicine, Hospital for Sick Children Research Institute, Toronto, ON, Canada, 3Lab Animal Services, Hospital for Sick Children, Toronto, ON, Canada, 4Anesthesia, University of Toronto, Toronto, ON, Canada, 5Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada, 6The Edward S. Rogers Sr. Department of Electrical & Computer Engineering, University of Toronto, Toronto, ON, Canada |
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Inspiring gases with altered O2 and CO2 levels is an approach to assess the health of the cerebral vasculature. However, application of this technique in the body is new and less well understood compared to its application in the brain. In this study, we adopt a comprehensive approach to investigate the MR signatures of abdominal tissue response to a wide spectrum of gas challenges. Results in the liver, kidney, and muscle of healthy rats confirmed T2* as a robust marker of blood oxygen saturation but suggested that T1, other than its conventional association to tissue oxygenation, may a marker of blood volume changes. |
| 3930 | Computer #95 |
Water-Fat MRI Detects Increased Brown Adipose Tissue Volume In Anticipation of Hibernation in Ground Squirrels |
1Biology, Western University, London, ON, Canada, 2Medical Biophysics, Western University, London, ON, Canada |
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During winter, brown adipose tissue (BAT) is the primary source of heat production in hibernating animals. White adipose tissue volumes increase and BAT-specific genes are upregulated in autumn even when temperatures are warm, but the rhythm of changes in BAT volume is unknown. Water-fat MRI was used to measure total BAT volume in hibernating squirrels two months after arousing from hibernation in spring and again at 18 days following the first MRI scan. BAT volumes increased significantly in this 20 day time period. |
| 3931 | Computer #96 |
Imaging of Dermal White Adipose Tissue in Mice |
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, WI, United States, 3Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 4Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 5Medicine, University of Wisconsin-Madison, Madison, WI, United States, 6Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States |
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Dermal white adipose tissue (DWAT) has only recently been recognized as a distinct adipocyte depot, with the potential to influence metabolism and physiology. In this study, we introduce a fat-water MRI approach for noninvasive quantification of the DWAT layer in mice on a clinical 3T scanner, and validate this approach using histology. As shown by MRI and histology, DWAT is thinner in Sdc1-/- mice compared to wild type. Interestingly, DWAT was dramatically thicker in an obese mouse model. |
| Exhibition Hall | Wednesday, May 11, 2016: 14:30 - 15:30 |
| 3932 | Computer #1 |
Simultaneous Determination of Metabolite Concentrations, Longitudinal and Transverse Relaxation Times |
1National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States |
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A data acquisition and quantification approach is proposed for simultaneous measurement of concentration, T1, and T2 of metabolites. The concentration, T1, and T2 of NAA, creatine, choline, glutamate and myo-inositol were determined reliably in less than 9 min using single voxel MRS at 7 Tesla. |
| 3933 | Computer #2 |
MR spectroscopy in the differentiation of benign, borderline and malignant cystic epithelial ovarian tumors |
1Department of Radiology, Obstetrics & Gynecology Hospital, Shanghai Medical College,Fudan University., Shanghai, China, People's Republic of, 2Department of Radiology, Jinshan Hospital, Shanghai Medical College,Fudan University, Shanghai, China, People's Republic of, 3Department of Radiology, Obstetrics& Gynecology Hospital, Shanghai Medical College, Fudan University, Shanghai, China, People's Republic of, 4Department of Radiology, Jinshan Hospital, Shanghai Medical College, Fudan University, Shanghai, China, People's Republic of |
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Because of the overlap in the imaging appearances of the benign, borderline, and malignant tumors, a considerable portion of cystic epithelial ovarian tumors(EOT) cannot be correctly diagnosedon conventional MR imaging. Recently, the rapid development of software and hardware has enabled the increasing application of proton magnetic resonance spectroscopy (1H-MRS) in ovarian tumors. However, 1H-MRS studies are still preliminary. To our knowledge, in vivo 1H-MRS differentiation of a single type of histopathological and morphological tumors has not yet been studied. We prospectively performed in vivo 1H-MRS of 86 patients with cystic EOT to understand the spectroscopic characteristics of different types of tumors and to investigate the ability of 1H-MRS in the differentiation of benign, borderline and malignant EOT. The results shows that 1H-MRS patterns of benign, borderline and malignant cystic EOT are different. The Cho/Cr ratio increases with the higher malignancy and a high Cho peak indicates a malignant tumor. A significantly elevated NAA peak indicates a borderline tumor. |
| 3934 | Computer #3 |
Prostate MRSI with reduced acquisition time and improved multichannel spectral processing |
1The University of Texas MD Anderson Cancer Center, Houston, TX, United States, 2GE Healthcare Technologies, Potsdam, Germany, 3GE Healthcare Technologies, Waukesha, WI, United States |
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Prostate MR spectroscopic imaging (MRSI) is limited with long acquisition time and need for an endorectal coil. Using an acquisition-weighted spectroscopic imaging sequence with an odd symmetric sampling scheme and a sorted singular value decomposition method for spectral processing of data from a multiple receive channels, we demonstrated that in vivo prostate MRSI can be performed at 3T in a substantially reduced scan time and without using an endorectal coil. Our proposed technique has the potential to help substantially expand the clinical use of prostate MRSI. |
| 3935 | Computer #4 |
Accelerated Magnetic Resonance Spectroscopic Imaging (MRSI) using Magnetic Resonance Fingerprinting (MRF) |
1Dayananda Sagar Institutions, Bangalore, India |
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Magnetic Resonance Spectroscopic Imaging (MRSI) is used as a tool to quantify metabolites in human brain and other organs. It is extensively used in clinical imaging and clinical research applications1. However, the major drawback of this technology is its long acquisition time which is the primary reason for not being used in the clinics. A novel approach of accelerating MRSI using Magnetic Resonance Fingerprinting (MRF) has been proposed in the current work. |
| 3936 | Computer #5 |
31P MRSI of Human Calf muscles Using Flyback Echo Planar Spectroscopic Imaging (EPSI) Readout Gradients |
1School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada, 2Imaging Research Centre, St Joseph's Healthcare, Hamilton, ON, Canada, 3Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada |
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Long acquisition time due to the low sensitivity is one of the main constrains for using 31P MRSI on a regular basis. Different methods have been proposed to accelerate the acquisition showing advantages and limitations. In this work we present for the first time an in vivo experiment using flyback-Echo Planar Spectroscopic Imaging readout and compare it with the traditional fidCSI sequence. Results suggest that the technique might be suitable for clinical applications. |
| 3937 | Computer #6 |
Improved Stability of the Inverse Laplace Transform with Non-negativity Constraints through Extension into a Second Dimension, with Applications to Magnetic Resonance Relaxometry of Tissue |
1Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States, 2Department of Mathematics, University of Maryland, College Park, MD, United States |
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Magnetic resonance (MR) relaxometry and related experiments provide useful information about tissues. These experiments reveal the distribution of a parameter, such as T2-relaxation, in a sample. The process required to recover the distribution from the observed data, an inverse Laplace transform (ILT), is highly ill-conditioned, meaning that small amounts of noise can create huge changes in the solution. Recent work has shown using simulations that 2D MR experiments result in a problem substantially more stable than in 1D. We present a theorem quantifying stability of the ILT and use it to explain the improved performance in 2D. |
| 3938 | Computer #7 |
31P MR Imaging with Radial bSSFP Data Acquisition and 1H Constraint Iterative Reconstruction |
1German Cancer Research Center (DKFZ), Heidelberg, Germany, 2University Medical Center Ulm, Ulm, Germany |
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Phosphorus (31P)-containing biomolecules play a crucial role in the energy metabolism of all cells. Since the in vivo MR signal of 31P is four orders of magnitude smaller compared to hydrogen, strategies to improve the signal-to-noise (SNR) are required. Therefore, this study focuses on the development of a signal-effective 31P acquisition in combination with a constraint iterative reconstruction applying prior knowledge from recorded hydrogen (1H) data. |
| 3939 | Computer #8 |
A Comparison of Rapid Acquisition Sodium T1 Mapping Techniques at 3T |
1Radiology, University of Cambridge, Cambridge, United Kingdom, 2Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom |
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Sodium T1 maps from three different Variable Flip Angle (VFA) methods were assessed against Inversion Recovery (IR) data, showing that the estimated method of slopes (eMOS) is superior to both linear and non-linear fitting methods in the healthy brain. eMOS requires two flip angle data sets to produce volumetric T1 maps of the brain, in comparison to other techniques which require 4 or more data sets to produce maps, and therefore allows for shortening of the overall time spent scanning. Furthermore, T1 maps may also give further insight in to the underlying tissue structure surrounding sodium nuclei. |
| 3940 | Computer #9 |
Assessment of benefit to use a non-Cartesian trajectory and nonlinear reconstruction method compared to a Cartesian strategy for Fast 31P MRI |
1MR Imaging and Spectroscopy Unit, NeuroSpin, Gif sur Yvette, France, 2Parietal, INRIA Saclay, Saclay, France, 3Institut des Technologies Avancées du Vivant, Toulouse, France, 4University Clinic RWTH Aachen, Aachen, Germany |
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This work illustrates the application of a wavelet based least square regularized image reconstruction for non-Cartesian MR sampling trajectories in the framework of low concentration Phosphorus Imaging. We compared performances between 3D Cartesian Fast Imaging with Steady-state free Precession (FISP) and the TPI (FISP) sequence and show that in equivalent acquisition durations we are able to produce better images with the TPI sequence. Prospective sub-sampling was also performed and results open exciting possibilities to reduce acquisition time without impacting image quality for non-proton MRI. |
| 3941 | Computer #10 |
Fast PCr Imaging of Rat Calf Muscles Using Spiral-In/Out bSSFP |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Radiology, Case Western Reserve University, Cleveland, OH, United States, 3Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, United States, 4Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States |
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In this study, a fast phosphocreatine (PCr) imaging method was developed by combining spectrally selective bSSFP with single-shot spiral-in/out encoding for measuring PCr distribution in vivo. 2 min acquisition yielded an SNR of ~9 in rat calf muscles with high spatial resolution (1.25 mm×1.25 mm×5 mm) at 9.4T. The SNR was increased to 25.5 with 30 min acquisition. This method also has the potential for imaging other metabolites such as ATP with a different carrier frequency, dynamic PCr imaging in exercise-recovery or ischemia-reperfusion studies, and quantification of the absolute metabolite concentration with appropriate T1, T2, and flip angle calibration/correction. |
| 3942 | Computer #11 |
Sensitivity Comparison of Ultrahigh-field Oxygen-17 MRS Imaging between 7T and 10.5T using a Human Head Size Phantom and Quadrature Surface Coil |
1CMRR, Radiology, University of Minnesota Medical School, Minneapolis, MN, United States |
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In vivo 17O MRS imaging provides a valuable tool for quantitatively imaging the cerebral rate of oxygen metabolism, cerebral blood flow and oxygen extraction fraction from a brief inhalation of 17O-isotope labeled oxygen gas. In this study, we conducted a pilot test to examine the 17O sensitivity using the human head size water phantom in the world's first 10.5T whole-body human scanner at the CMRR, then compared it with that at 7T. We found approximately doubled 17O sensitivity at 10.5T after careful consideration signal and noise contributions at both fields. |
| 3943 | Computer #12 |
A Beating Heart Simulation for Sequence Optimization of Sodium MRI |
1MR-Imaging and Spectroscopy, University of Bremen, Bremen, Germany, 2Fraunhofer MEVIS, Bremen, Germany |
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Sodium MRI can act as a biomarker for heart tissue viability. However, several aspects (blurring behavior of non-Cartesian ultra-short echo time sequences, blurring because of heart motion, small myocardial infarction (MI) regions) complicate MI detection due to resolution reasons. Optimal sequence parameters are difficult to find since many subject parameters (e.g., relaxation times, heart motion) must be considered. The presented simulation model of a beating heart can be used to optimize sequence parameters, among other things, for better visualization of MI and can be adapted to any kind of motion and to different subject/physiological parameters. |
| 3944 | Computer #13 |
31P MR Imaging and Concentration Measurements |
1MR Imaging and Spectroscopy Unit, NeuroSpin, Gif sur Yvette, France, 2Parietal, INRIA Saclay, Saclay, France, 3Siemens Healthcare, Saint Denis, France, 4University Clinic RWTH Aachen, Aachen, Germany |
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This work describes a novel method accounting for MR acquisition properties (B0, B1+,B1-,T1,T2*) to perform concentration measurements in the framework of in vitro Phosphorus MRI. Our pipeline uses a non-Cartesian 3D sequence for efficient signal sampling and a wavelet regularized least square method for reconstruction. We demonstrated within an acceptable time for human experiment, for 5mm isotropic resolution, that we are able to calibrate and measure absolute 31P concentrations. |
| 3945 | Computer #14 |
Mapping of sodium and water content ratio in vivo in the human calf |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Diagnostic and Interventional Radiology, University Medical Center Ulm, Ulm, Germany |
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Both lower legs of three male healthy volunteers were examined at 3 T and 7 T by means of 1H and 23Na MRI to obtain quantitative maps of the sodium and water content in muscle tissue. Corrections for T2* and T1 relaxation and RF profiles (B1+, B1–) were performed. The resulting water content value in calf muscle tissue was in the range of 75–85 mol/l, the level of sodium was 15–21 mmol/l (sodium-to-water content ratio: 0.20–0.27 ‰). |
| 3946 | Computer #15 |
Phase Modulated Array Coil Image Reconstruction: A means to correct B1+/- signal modulations for sodium Tx/Rx Array Coil at 3T |
1Radiology, New York University, New York, NY, United States, 2Siemens Medical Solutions USA, New York, NY, United States |
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A transmit/receive (Tx/Rx) array coil has high efficiency in transmission and thus reduces specific absorption rate (SAR), which is highly desired in clinical applications for sodium (23Na) MR imaging. However, a Tx/Rx array coil at 3T usually produces a spatially-varying excitation (B1+) field and does not provide a uniform sum-of-squares of coil sensitivities (B1- fields) for quantitative sodium MRI. Here we present a solution to this problem and demonstrate its effectiveness with studies on phantoms and subjects with neurological disorders such as multiple sclerosis (MS), epilepsy, and mild traumatic brain injury (mTBI). |
| 3947 | Computer #16 |
Spectral Quantification of MRSI Data Using Spatiospectral Constraints |
1Electrical and Computer Engineering, University of Illinois, Urbana-Champaign, Urbana, IL, United States, 2Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, Urbana, IL, United States |
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A new method is proposed for spectral quantitation of MRSI data. The method has two main features: 1) incorporation of prior spectral knowledge in the form of basis functions obtained by quantum simulation, and 2) incorporation of prior spatial knowledge by penalizing smoothness within each type of tissue. An efficient algorithm is also proposed to solve the underlying optimization problem, and its effectiveness for extracting quantitative spectral information from noisy MRSI data is demonstrated by comparing it with one of the state-of-the-art methods. |
| 3948 | Computer #17 |
Flexible flyback EPSI Waveform Generation under the Constraint of Peripheral Nerve Stimulation |
1GE Healthcare, Potsdam, Germany, 2GE Global Research, Munich, Germany |
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Echo-Planar Spectroscopic Imaging (EPSI) reduces the long acquisition time of Chemical Shift Imaging. “Flyback” trajectories sampling the lobe only along one direction are commonly used for robustness and artifact reasons. Main challenge in the design is that there is no analytic solution for an SNR optimized readout/flyback trapezoid pair. The goal of this work was to implement a fast SNR optimized algorithm that takes Peripheral Nerve Stimulation into account to calculate waveforms on the fly for any given spectral and spatial resolution and therefore doesn’t require pre-calculated waveforms. |
| 3949 | Computer #18 |
A pilot validation of compressed sensing four dimensional multi-echo based echo-planar J-resolved spectroscopic imaging in human brain |
1Radiological Sciences, UCLA School of Medicine, Los angeles, Los Angeles, CA, United States |
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Phase encoded MR spectroscopic imaging (MRSI) is a time-consuming protocol because there is a large number of phase encodings to be collected. Non-uniform undersampling (NUS) and Compressed Sensing (CS), which has been widely used in MRI/MRS can be used to speed up the acquisition further. In this study, we have implemented a novel CS based multi -echo echo planar J-Resolved spectroscopic imaging (ME-EP-JRESI) acquisition and CS reconstruction in in human brain at 3T. We were able to detect and quantify several metabolites using a modified ProFit algorithm. The CS reconstructed spectra were of high quality, with metabolite ratios matching the fully encoded data closely. |
| 3950 | Computer #19 |
Accelerated Five-Dimensional Echo Planer J-resolved spectroscopic imaging: Pilot findings in untreated and CPAP treated Obstructive Sleep Apnea |
1Radiological Sciences, UCLA School of Medicine, Los angeles, Los Angeles, CA, United States, 2School of Nursing, UCLA School of Medicine, Los angeles, Los Angeles, CA, United States, 3Division of Pulmonary and Critical Care Medicine, UCLA School of Medicine, Los angeles, Los Angeles, CA, United States |
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With the rise of people with obesity and older age, obstructive sleep apnea (OSA) has become a potentially disabling health problem. Continuous positive airway pressure (CPAP) is the most common treatment method for OSA patients. Here we examined neurochemical changes of untreated and CPAP treated OSA patients versus healthy controls in several brain region including parietal gray/white, insular cortex and frontal gray/white regions to demonstrate the nature of tissue changes using an accelerated five-dimensional (5D) echo-planar J-resolved spectroscopic imaging (EP-JRESI) sequence. We observed statistically significant differences between OSA patients and healthy control subjects in the occipital gray NAA/Cr, frontal gray Ch/Cr and mI/Cr, and occipital white Ch/Cr regions. Most of the differences were seen to be reversed in the OSA patients’ with CPAP cohort except that the differences in occipital gray NAA/Ch and frontal gray mI/Cr remained significance. To validate our findings, further longitudinal studies using a large cohort of OSA subjects before and after CPAP are required. These pilot findings demonstrate that the 5D EP-JRESI sequence can be easily combined with any MRI protocol. |
| 3951 | Computer #20 |
2D MR Spectroscopic Imaging of the Pediatric Brain using Compressed Sensing |
1Biomedical Engineering, Arizona State University, Tempe, AZ, United States, 2Radiology, Phoenix Children's Hospital, Phoenix, AZ, United States, 3Banner MD Anderson Cancer Center, Gilbert, AZ, United States |
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The spatial variations in brain metabolite concentrations can be mapped using magnetic resonance spectroscopic imaging (MRSI). The long scan times in MRSI do not permit its inclusion in pediatric imaging protocols. MRSI accelerated by compressed sensing was used to image the pediatric brain for various acceleration factors 2X-5X. The retrospectively undersampled reconstructions showed high data fidelity for up to 80% undersampling when compared with the fully sampled reference dataset. Studies are underway to prospectively acquire and validate CS accelerated MRSI data in pediatric patients. |
| 3952 | Computer #21 |
WITHDRAWN |
1UCBerkeley/UCSF Joint Graduate Group in Bioengineering, University of California Berkeley, Berkeley, CA, United States, 2Department of Radiology and Biomedical Imaging, Surbeck Laboratory of Advanced Imaging, San Francisco, CA, United States |
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This work investigates the feasibility of using GRAPPA-EPSI based reconstruction of the short-echo 3D MRSI to shorten the acquisition time and to increase the spatial resolution for future routine clinical purposes. Fully sampled data were retrospectively under-sampled to achieve effective acceleration rate of 2, 3 and 4 using variety of sampling patterns. GRAPPA algorithm was modified to take advantage of the FID time points and handle the arbitrary sampling patterns. Additional technique was also developed to prospectively udner-sample in-vivo data with various patterns for future studies. |
| 3953 | Computer #22 |
Enhanced T2 Spectroscopic Imaging Using Backprojections (SI-WEB): A Simulation Study |
1Radiological Sciences, University of California - Los Angeles, Los Angeles, CA, United States |
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Measuring the transverse relaxation times (T2s) of metabolites from different regions of the brain provides important insight into different pathologies, but requires long acquisition. A novel k-space acquisition using a hybrid technique involving both echo planar spectroscopic imaging (EPSI) and concentrically circular echo planar trajectories (SI-CONCEPT) was applied to simulated brain tumor spectroscopic imaging data. In addition, an algorithm incorporating the backprojection information from the EPSI scan was developed to enhance the spectroscopic images. This novel acquisition and reconstruction technique, called SI-WEB, decreases the total duration of the scan while producing similar results when compared to the true T2 spectroscopic images. |
| 3954 | Computer #23 |
Compressed Sensing 3D Echo Planar Spectroscopic Imaging of HIV Adults |
1Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States, 2Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA, United States |
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HIV affects more than 1 million individuals In the US and over 40 million people worldwide. CNS is commonly involved in the early stage HIV infection. Conventional 3D MRSI is time-consuming because it involves a large number of phase encodings. EPSI approaches have been used to reduce the long acquisition time required for multiple spatial encoding steps. In our study, non-uniformly undersampled (NUS) semi LASER based 3D EPSI was used to quantitate changes in brain metabolites, NAA, Cr, Cho and myo-inositol in a group of HIV adults in comparison to age matched control sample using compressed sensing reconstruction by minimizing total variation. |
| 3955 | Computer #24 |
Denoising of MR Spectroscopic Imaging Data Using Statistical Selection of Principal Components (SSPC) |
1Radiology, University of Miami, Miami, FL, United States, 2Radiation Oncology, University of Miami, Miami, FL, United States |
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In this study we evaluate a new principal components analysis (PCA) based denoising method for volumetric MRSI data that employs a statistical test for the selection of the significant noise-free principle components (PCs). |
| Exhibition Hall | Wednesday, May 11, 2016: 14:30 - 15:30 |
| 3956 | Computer #25 |
A Subspace-Based Approach to High-Resolution 31P-MRSI |
1Beckman Institute, University of Illinois Urbana-Champaign, Urbana, IL, United States, 2Electrical and Computer Engineering, University of Illinois Urbana-Champaign, Urbana, IL, United States |
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Conventional Fourier based phosphorus (31P)-MRSI methods have been limited by spatial resolution due to the low concentrations of phosphate-contained chemical compounds in the human body and the relatively low sensitivity of 31P NMR. This work presents a subspace-based data acquisition and reconstruction method to achieve accelerated, high-resolution 31P-MRSI. The feasibility of the proposed method is demonstrated using both phantom and in vivo experimental studies on a 3T scanner, which have yielded very promising results. The proposed method can be used in a range of 31P-MRSI applications. |
| 3957 | Computer #26 |
31P Magnetic Resonance Fingerprinting Method for Efficient Measurement of Creatine Kinase Mediated High Energy Phosphate Metabolism |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Radiology, Case Western Reserve University, Cleveland, OH, United States |
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We propose a novel 31P Creatine Kinase encoding Magnetic Resonance Fingerprinting method (CK-MRF) to efficiently measure high energy phosphate metabolism through creatine kinase (CK). Measurement reproducibility of CK rate constant (kf,CK) using CK-MRF was compared with both conventional 31P saturation transfer method, and Four Angle Saturation Transfer method in rat hind limb. CK-MRF measurement showed comparable or superior reproducibility using 20 s experiment time compared to 160 s experiment time of either comparison method. Changes in kf,CK following Ischemia/Reperfusion (IR) were also measured. |
| 3958 | Computer #27 |
Citrate production in prostate cancer metastasis cell lines LNCaP and VCaP |
1Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands, 2Urology, Radboud University Medical Center, Nijmegen, Netherlands |
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Citrate production by prostate cancer cell lines LNCaP and VCaP were studied with 13C-NMR spectroscopy. Glucose acts as carbon source for citrate production in LNCaP and VCaP cell lines, but not aspartate, in contrast to expectation. Also pyruvate and glutamine can act as carbon sources for citrate production in LNCaP. Anaplerosis via pyruvate carboxylase is found to be low in these cells. Glutamine label only ends up in citrate via isocitrate instead of downstream in the Krebs cycle. These typical features of citrate metabolism might serve as valuable biomarkers for transition from healthy prostate cells to malignant cells. |
| 3959 | Computer #28 |
Myocardial energetics in patients with degenerative mitral regurgitation studied by 31P MRS |
1Clinical Imaging Research Center, A*STAR & National University of Singapore, Singapore, Singapore, 2Department of Medicine, Yong Loo Lin School of Medicine and Cardiovascular Research Institute, National University Health System, Singapore, Singapore |
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31P MRS can noninvasively reflect the in vivo energy metabolism without using ionizing radiation. It has been widely applied in the clinical studies of cardiac energetics under different pathophysiological conditions. The aim of the present study was to evaluate the myocardial energetics in 30 patients with moderate or severe degenerative mitral regurgitation (DMR) using 31P MRS. |
| 3960 | Computer #29 |
Measurement of ATP Synthesis in Human Brain by 31P Localized Band Inversion Transfer at 7T |
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States |
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Despite recent advances in measuring ATP energy metabolism using 31P magnetization transfer, there is still a lack of localized techniques capable of assessing the regional ATP synthesis. The importance of measuring regional ATP rates and fluxes in the human brain is highlighted by the heterogeneity in normal brain functions and also in many cerebral metabolic abnormalities. In this study, we demonstrate that, by combining wide-band inversion transfer with image selected in vivo spectroscopy (ISIS), quantitative information regarding ATP synthesis reaction Pi ==> γ-ATP can be obtained from the localized regions in the human brain. |
| 3961 | Computer #30 |
7T allows correct measurement of PDE in the human liver without decoupling |
1OCMR, Department of Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom |
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Phosphomonoesters (PME) and phosphodiesters (PDE) are emerging biomarkers in cirrhosis and fatty liver disease. In this study, phosphorus (31P) liver metabolite concentrations were quantified at 7T for 10 healthy volunteers using a 28 minute, 3D UTE-CSI sequence and an endogenous 2.5mM ATP reference. The inorganic phosphate concentration was 1.95 ± 0.18mM (1.25-2.43mM in the literature). Summing individual ester peaks, the total PME and PDE concentrations were 1.90 ± 0.29mM (cf. 1.98-3.89mM) and 4.31 ± 0.80mM (cf. 8.01-11.40mM). We attribute this apparent reduction in PDE to a broadening of the underlying phospholipid bilayer resonance and the increased spectral resolution at 7T. |
| 3962 | Computer #31 |
Simultaneous Assessment of Abnormal Glycolysis and Oxidative Metabolisms in Brain Tumor using In Vivo Deuterium MRS Imaging |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Neurosurgery, University of Minnesota, Minneapolis, MN, United States |
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Recently, we developed a novel 3D-Deuterium MR (DMR) approach able to simultaneously image glucose consumption rate and TCA cycle flux in rat brain at ultrahigh field. To evaluate its sensitivity in detecting altered metabolism, in this study, we acquired localized DMR spectra in rat brains with gliosarcoma following a brief infusion of deuterated glucose at 16.4 T. We observed accelerated glucose consumption and lactate accumulation accompany with decreased glutamate/glutamine turnover in brain regions with tumor. This pilot study demonstrates the feasibility of the in vivo DMR imaging approach for investigating abnormal glucose metabolism in brain tumor at ultrahigh field. |
| 3963 | Computer #32 |
In Vitro Oxygen-17 NMR Spectroscopy of Cellular Metabolism at Ultra High Field |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, 2NUKEM Isotopes Imaging GmbH, Alzenau, Germany, 3Institute for Biological Interfaces 5, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany, 4Department of Complex Tissue Regeneration, MERLIN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, Netherlands |
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In this work we present a novel in vitro oxygen-17 NMR method using 17O-labeled glucose to investigate the metabolic process of cells cultivated in a MR-compatible microbioreactor. The metabolization of 17O-labeled glucose was demonstrated to produce MR-detectable H217O on the one hand and to not intervene with the inherent cellular physiology on the other hand, thus proving the method to serve as a neutral observation platform. The presented method has the potential to aid the modeling of fundamental physiological processes and to become a key element in cellular vitality assessment applications. |
| 3964 | Computer #33 |
Initial investigation of glucose metabolism in mouse brain using enriched 17O-glucose and dynamic 17O-MRS |
1University Medical Center Freiburg, Dept. of Radiology - Medical Physics, Freiburg, Germany, 2German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany, 3NUKEM Isotopes Imaging GmbH, Alzenau, Germany |
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In this work, we demonstrate the feasibility of monitoring glucose uptake in mouse brain using direct 17O-MRS at 9.4 Tesla for the first time. Time-resolved 17O-MRS spectra (temporal resolution: 42 s) are acquired in vivo after injection of D-glucose with 17O-labeled hydroxyl groups. The cerebral rate of glucose metabolism CMRGlc is estimated using a pharmacokinetic model in an anesthetized (1.25% isoflurane) mouse to 0.43 ± 0.21 µmol/g/min, which is of the same order of magnitude as reported by 18F-FDG PET. |
| 3965 | Computer #34 |
Evaluation of High Temporal and Spatial Resolution 17O-MRI |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Diagnostic and Interventional Radiology, University Medical Center Ulm, Ulm, Germany |
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Functional information of cell and tissue viability can be obtained via dynamic 17O-MRI. The quantification of H217O-concentration as a turnover product of oxidative phosphorylation in combination with 17O2-inhalation enables mapping of the cerebral metabolic rate of oxygen consumption (CMRO2). Due to low MR-sensitivity of the 17O-nucleus, spatial as well as temporal resolution is limited. Induced partial volume effects hinder accurate and stable signal quantification which is essential for dynamic studies. High resolution 17O-data with (4.5mm)3 was acquired with a Golden Angle acquisition scheme which allowed reconstruction of arbitrary time-frames. A partial volume correction algorithm was applied to test correction capability of data of different temporal resolution. |
| 3966 | Computer #35 |
Iterative Approach for Partial Volume Corrected T2* Determination in 17O-MRI |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Diagnostic and Interventional Radiology, University Medical Center Ulm, Ulm, Germany |
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The energy balance of a cell is closely connected to in-vivo H217O-concentration which also is the turnover product of oxidative phosphorylation. 17O-MRI during inhalation of 17O2 enables localized mapping of cerebral metabolic rate of oxygen consumption (CMRO2). Larger voxel sizes due to a low MR-sensitivity and short relaxation times induce partial volume effects which reduce quantification accuracy. For accurate signal correction exact T2*-values are essential. A partial volume correction algorithm for improved T2*-determination where T2*-values are adapted iteratively is presented. Consistent results to simulations were obtained for phantom and in-vivo data. The iteratively corrected in-vivo T2*-values were used for improved 17O-MRI-signal quantification. |
| 3967 | Computer #36 |
Random under-sampling and spectra reconstruction for in vivo 13C magnetic resonance spectroscopy |
1National Institute of Mental Health, Bethesda, MD, United States |
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The present study proposes and evaluates a novel under-sampled decoupling strategy in which no decoupling was applied during randomly selected segments of data acquisition. By taking advantage of the sparse spectral pattern of carboxylic/amide region of in vivo 13C spectra of brain, an iterative algorithm was developed to reconstruct spectra from under-sampled data. Simulations and in vivo experiments show that this novel decoupling and data processing strategy can effectively reduce decoupling power deposition by >30%. |
| 3968 | Computer #37 |
Energy metabolism in the rat cortex under thiopental anaesthesia measured in vivo by 13C MRS at 14.1T |
1Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polythechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 2Universitätsklinikum Münster, Münster, Germany, 3Center for Biomedical Imaging (CIBM) and Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 4Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland |
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Cerebral function relies on cooperative interaction between neuronal and glial cells. Anaesthetics modulate basal neuronal activity, and therefore the so-called neurometabolic coupling, by targeting different receptors, such as γ-aminobutyric acid type A (GABAA) receptors, in the case of thiopental or α-chloralose anaesthesia. We investigated cortical metabolism in vivo using 13C magnetic resonance spectroscopy (MRS) during infusion of [1,6-13C]glucose under thiopental anesthesia. Data indicate glycolysis inhibition, decreased mitochondrial oxidative metabolism and possible oxidation of three-carbon molecules, namely lactate, which plasma concentration increased two-fold (compared to α-chloralose anaesthesia). |
| 3969 | Computer #38 |
In vivo measurement of metabolic fluxes in mouse dorsal hippocampus using 1H-[13C] NMR spectroscopy at 14.1 Tesla |
1Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2Department of Radiology, University of Geneva, Geneva, Switzerland, 3Animal Imaging and Technology Core (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 4Department of Radiology, University of Lausanne, Lausanne, Switzerland |
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1H-[13C] MRS was applied in a mouse dorsal hippocampus to investigate brain metabolism in vivo. The measured fractional enrichments allowed to measure metabolic fluxes using a one compartment model of glucose metabolism. Results were similar to previous study using a 3 times bigger voxel. This study shows that metabolism of the mouse dorsal hippocampus, which is one of the most studied structures of the brain, can be assessed in vivo. |
| 3970 | Computer #39 |
Measuring Glycolysis versus Oxidative Phosphorylation in Human Sperm by 13C MR Spectroscopy |
1Academic unit of radiology, University of Sheffield, Sheffield, United Kingdom, 2Academic Unit of Reproductive and Developmental Medicine, University of Sheffield, Sheffield, United Kingdom |
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Two main metabolic pathways provide energy for sperm swimming; glycolysis and oxidative phosphorylation, producing different biomarkers, including lactate (glycolysis) and bicarbonate/CO2 (Oxphos) that can be detected by MR spectroscopy. By incubating 13C labeled exogenous metabolites with human spermatozoa we identify metabolic pathways and quantify rates of metabolism in spermatozoa. The rate constants for glucose and pyruvate conversion to lactate were estimated as 1.1±0.5x10-6s-1 and 2.4±1.1x10-6s-1 per million sperm respectively (mean±SD, n=4). Metabolic pathways used by live sperm were assessed and work is being done to estimate the relative importance of different metabolic activity in sperm of normozoospermic and asthenozoospermic patients. |
| 3971 | Computer #40 |
Towards direct detection of natural abundance glycogen C2-C6 resonances by localized 13C MRS at 7T. |
1Laboratory of Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 2Image Guided Interventions Laboratory, Radiology Department, University of Geneva (UNIGE), Geneva, Switzerland, 3Centre d'Imagerie Biomédicale - Animal and Imaging Technology (CIBM-AIT), Lausanne, Switzerland, 4Department of Radiology, University of Lausanne (UNIL), Lausanne, Switzerland, 5Department of Radiology, University of Geneva (UNIGE), Geneva, Switzerland |
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Glycogen is the main energy store in the human body, while its concentration is particularly abundant in muscle tissue. In vivo 13C MRS is unique for investigating glycogen metabolism, as it allows the non-invasive measurement of natural abundance glycogen C1 resonance in the human muscle. However, spatial localization is desirable to detect glycogen C2-C6 resonances due to their overlap with the glycerol C2 and C1, C3 resonances. In this study, we designed a pulse-acquire sequence for localized 13C MRS using ISIS-1D and OVS schemes. The localization performance of the sequence was validated in vitro and in vivo in human muscle at 7T. |
| 3972 | Computer #41 |
Comparison of in vivo potassium, chloride and sodium TQ effects at 21.1 T |
1NHMFL/FSU, Tallahassee, FL, United States, 2University of Heidelberg, Mannheim, Germany, 3German Cancer Research Center (DKFZ), Heidelberg, Germany, 4Lawrence Berkeley National Laboratory/ UCB, Berkeley, CA, United States |
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A comparison of the TQ MR signals without filtration from three in vivo ions was performed in a rat head at 21.1 T using a time proportional phase increment. A strong and competitive binding of potassium relative to sodium was demonstrated and confirmed using agarose samples. The TQ signal from in vivo chloride was the lowest. Our results support a model that normal cells have similar ion binding in intracellular and extracellular spaces. Visualization of TQ magnetization was demonstrated using matching angular dependence of spherical harmonics and corresponding irreducible tensors. |
| 3973 | Computer #42 |
Does Tempol enter the brain with an unpaired electron? |
1Center for Medical Education, Sapporo Medical University, Sapporo, Japan, 2Osaka University, Osaka, Japan |
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Nitroxides have unique biochemical properties, and thus they have been used for many biomedical applications. However, although piperidine nitroxide (4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl: Tempol) has been presently tested in clinical trials, details concerning the distribution and kinetics of Tempol in vivo have not been thoroughly studied. In particular, it is not clear whether Tempol enters the brain as paramagnetic materials with an unpaired electron. To examine this matter, electron paramagnetic resonance (EPR) imaging study of mouse brains was conducted using a modified EPR imager. The obtained EPR images clearly showed that Tempol could enter the brain with an unpaired electron. |
| 3974
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Computer #43 |
Comparison of a 30-channel head array with a birdcage for 23Na MRI at 7 Tesla |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Rapid Biomed, Rimpar, Germany, 3Diagnostic and Interventional Radiology, University Medical Center Ulm, Ulm, Germany |
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A 30 channel Rx array for 23Na MRI at 7 Tesla is compared with a reference Tx/Rx birdcage. Strong SNR improvement by the array technology is acknowledged and good B1 homogeneity could be found. Images were reconstructed using der adaptice combine algorithm which provides a near perfect channel combination. |
| 3975 | Computer #44 |
Reconstruction of asymmetrically undersampled high-resolution 23Na-MRI data after homodyne processing |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Diagnostic and Interventional Radiology, University Medical Center Ulm, Ulm, Germany |
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Due to the low concentration of 23Na in the human body, 23Na-MRI suffers from long acquisition times Taq, especially for high nominal spatial resolutions. In this work we investigated the performance of homodyne data processing prior to the iterative 3D-Dictionary-Learning Compressed Sensing reconstruction (3D-DLCS) for the reconstruction of asymmetrically undersampled radial 23Na-data, in order to take advantage of the point-symmetry in k-space. |
| 3976 | Computer #45 |
The venous contribution to sodium (23Na) MRI signals in human brain |
1CUBRIC, School of Psychology, Cardiff University, Cardiff, United Kingdom, 2Department of Biomedical Engineering, University of Alberta, Edmonton, AB, Canada |
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We show for the first time that venous sodium MRI signals in the human brain are elevated with respect to grey and white matter in-vivo. These results have implications for studies using sodium MRI signals to investigate pathologies such as stroke and cancer, with abnormal cerebrovasculature. Observed signal changes in these groups may be partially due to changes in vascular structure, rather than metabolic dysfunction or disruption of cell integrity. Also, potential studies aiming to use sodium MRI for direct detection of neuronal activity will need to account for functional hyperaemia changing the venous sodium signal. |
| 3977 | Computer #46 |
Development and Application of a 23Na Elliptical Body Coil for 7 Tesla |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Diagnostic and Interventional Radiology, University Medical Center Ulm, Ulm, Germany, 3Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany |
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Up to now only a few 23Na abdominal MRI studies have been performed at 7T. In this work, a versatile 23Na transceive elliptical-shaped body coil for 7T with a large FOV and a high transmit/receive efficiency was designed, simulated, and implemented on a 7T scanner. The setup was applied for in-vivo imaging of the human torso. The obtained 3D 23Na image data set contains 23Na signals from heart to pelvis. High regional 23Na signals are especially present in the areas of kidney, liver, cartilage, vessels, vertebral disks, spinal canal, and heart. |
| 3978 | Computer #47 |
Standardisation and quantification of 23Na-MRI: repeatability and reproducibility of sodium imaging across two independent sites |
1Centre for Imaging Sciences, The University of Manchester, Manchester, United Kingdom, 2CRUK & EPSRC Cancer Imaging Centre in Cambridge & Manchester, United Kingdom, 3Department of Radiology, University of Cambridge, Cambridge, United Kingdom, 4Bioxydyn Ltd., Manchester, United Kingdom |
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This work investigates the repeatability and reproducibility of total sodium concentration (TSC) estimates in the human brain. Healthy volunteers were scanned twice at two different sites using comparable 3D Cones acquisitions, and region of interest TSC values were compared. Consistent TSC estimates were observed across repeated scans at different sites, and, for robust multi-site comparisons, a need was identified for standardisation of non-Cartesian data reconstruction. These preliminary results provide an initial step in the technical validation of sodium MRI-derived cancer biomarkers. |
| 3979 | Computer #48 |
Development of translational simple multinuclear MRI system for ultra high-field |
1Institute of Neuroscience and Medicine-4, Research Centre Juelich, Juelich, Germany, 2Faculty of Medicine, Department of Neurology, JARA, RWTH Aachen University, Aachen, Germany |
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Non-proton MRI has recently been of great interest with the increased availability of ultra high-field MRI system. A translational multinuclear MRI system for 1H, 13C, 17O, 19F, 23Na and 31P was developed using six optimised single-tuned RF resonator sets and implemented at the home-assembled 9.4T small animal MRI scanner. This system demonstrated its capability of identifying the concentration difference and sensitivity of these X-nuclei without signal-to-noise-ratio loss for any nuclei, subject interruption and degrading in the static shim condition. |
| Exhibition Hall | Wednesday, May 11, 2016: 14:30 - 15:30 |
| Exhibition Hall | Wednesday, May 11, 2016: 14:30 - 15:30 |
| 4004 | Computer #73 |
On the composition of Glx in MEGA-PRESS measurements at 3T, is it glutamate? |
1Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, Netherlands, 2School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands, 3Russel H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, 4F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 5Epilepsy Center Kempenhaeghe, Heeze, Netherlands |
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Some authors claim that the 3.7 ppm Glx peak, measured with MEGA-PRESS, constitutes predominantly glutamate. This claim was tested measuring nine phantoms with different glutamate, glutamine, and GABA concentrations using a MEGA-PRESS sequence on a 3T MR scanner. The spectra were analyzed with Gannet (to measure the Glx peak) and LCModel (as an alternative approach). The results show that both glutamate and glutamine attribute to the Glx peak, but that an exclusive estimation of glutamate and glutamine is possible by using LCModel for analysis. |
| 4005 | Computer #74 |
The anterior cingulate cortex GABA levels with varied tissue composition measured by in vivo single voxel MRS |
1Shanghai Key Laboratory of Magnetic Resonance and Department of Physics, East China Normal University, Shanghai, China, People's Republic of, 2MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China, People's Republic of |
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Owing to relatively low concentration of GABA in the brain, a large voxel size is normally applied in MRS to achieve a high signal-to-noise ratio, but with combined signal from white matter, gray matter and cerebrospinal fluid. The tissue contribution in GABA measurement remains to be resolved. GABA levels from three closely adjacent voxels with varied tissue composition in the anterior cingulate cortex were acquired by using MEGA-PRESS. GABA level was found to be significantly higher in gray matter than in white matter. |
| 4006 | Computer #75 |
Quadrature 31P and single 1H dual-tune coil for cardiac 31P-MRS at 7T |
1RDM Cardiovascular Medicine, University of Oxford, OXFORD, United Kingdom, 2Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich GmbH, Juelich, Germany |
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Phosphorus spectroscopy is a powerful tool for cardiac metabolism studies. Working at 7T gives a significant (2.8x) gain in SNR compared to 3T. However, with existing RF coils, it is hard to excite the heart uniformly and with sufficient peak B1+. In this work we simulated 8 candidate coil designs and identified the best one for cardiac 31P-MRS. We built this quadrature pair of 15cm loops for 31P and a single 10cm loop for 1H, decoupled with LCC traps, performed safety tests, validated its B1+ in phantoms and recorded spectra in vivo in the human leg, liver and heart. |
| 4007 | Computer #76 |
Metabolite diffusion up to very high b in the mouse brain in vivo: revisiting the correlation between relaxation and diffusion properties |
1CEA/DSV/I2BM/MIRCen, Fontenay aux Roses, France, 2CNRS Université Paris-Saclay UMR 9199, Fontenay aux Roses, France |
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Diffusion-weighted magnetic resonance spectroscopy is performed in a large voxel in the mouse brain at two diffusion times, up to very high b-values. We combine different echo times and mixing times to investigate the potential interplay between relaxation properties and diffusion attenuation. Under current experimental conditions, we don’t observe any significant dependence of metabolite diffusion properties on TE/TM, except for water (and possibly NAA at very high b-values), which supports the interpretation and modeling of metabolite diffusion based primarily on geometry, irrespective of relaxation properties. |
| 4008 | Computer #77 |
MEGA-PRESS Single-voxel Spectroscopy for GABA J-editing with Real-time Frequency Adjustment |
1Siemens Healthcare, San Francisco, CA, United States, 2Siemens Healthcare, Baltimore, MD, United States, 3Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, 4CIND, Veterans Affairs Medical Center, San Francisco, CA, United States |
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Spectroscopy scan is highly sensitive to frequency drift during the acquisition. Although most spectroscopy sequences do not create large frequency drift themselves, it is problematic when they are run immediately after sequences with high gradient duty-cycle, as the frequency still drifts due to gradient cooling. In this paper, realtime frequency adjustment was implemented for MEGA-PRESS sequence for GABA J-editing. FID signal was read during water suppression and used to calculate and update the system frequency every TR cycle. It was tested on a phantom and in vivo and showed effectiveness by providing insensitivity to the frequency drifts during the acquisition. |
| 4009 | Computer #78 |
Toolbox for automatic localization of volume of interest in MRS (ALLVOI) |
1Electronic and Computer Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, 2Graduate Institute of Applied Physics, National Chengchi University, Taipei, Taiwan, 3Reasearch Center for Mind,Brain and Learning, National Chengchi University, Taipei, Taiwan |
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Magnetic Resonance Spectroscopy (MRS) data were usually acquired with single voxel spectroscopy techniques (SVS), which is used to access metabolites concentrations from a predefined volume of interest (VOI). Currently, MRS has been linked to fMRI studies to access metabolic information. Therefore, it’s important to define the VOI on standard space (template) and transform the predefined VOI from standard space to subject space for each MRS scan. In this study, we developed a tool to guide the definition of VOI on template before MRS scan then automatically calculate VOI in subject space. |
| 4010 | Computer #79 |
Downfield spectra of human brain obtained with and without water suppression at 9.4T |
1Depts. Radiology and Clinical Research, University of Bern, Bern, Switzerland, 2Institute for Biomedical Engineering, UZH and ETH Zurich, Zurich, Switzerland, 3Max Planck Institute for Biological Cybernetics, Tuebingen, Germany |
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Ultra high field strengths offer the benefit of higher signal to noise ratio as well as improved separation of metabolites in spectroscopy, which is beneficial for evaluating downfield peaks. In the current work, the metabolite cycling technique is implemented at 9.4T in order to evaluate the downfield part of the human brain spectrum. The 9.4T spectra confirm the 3T findings on exchanging peaks, and indicate that the higher field strength improves metabolite separation, allowing for better quantification of exchanging peaks, which is also of great interest for chemical exchange dependent saturation transfer experiments. |
| 4011 | Computer #80 |
1H MRS of gray and white matter in the human brain using B0 Adjusted Sensitivity Encoded Spectral Localization by Imaging (BASE-SLIM) |
1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States, 2Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, United States, 3Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States |
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Reliable localization of 1H MRS in gray and white matter of the human brain was achieved using the BASE-SLIM technique. Distinctive spectral patterns of gray and white matter were measured from all subjects using BASE-SLIM, which were consistent with those measured in both tissue types using single-voxel 1H MRS. BASE-SLIM spectroscopy promises 1) accurate and robust acquisition of MR spectra from gray and white matter with minimum cross contamination from other compartments, 2) shorter scan time and 3) flexibility in compartmental shapes that match anatomical structures. |
| 4012 | Computer #81 |
Parameter optimization for reproducible cardiac 1H-MR Spectroscopy at 3 T |
1CJ Gorter Center, Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Radiology, Leiden University Medical Center, Leiden, Netherlands |
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Cardiac proton MR spectroscopy is a challenging technique to perform in a reliable manner. In this study data acquisition parameters are optimized in terms of signal-to-noise and reproducibility. The optimal protocol was determined to be a PRESS localized scan, local power optimization, pencil beam B0 shimming, a cardiac trigger delay of 200 ms, MOIST water suppression and pencil beam navigator-based respiratory compensation. With these parameters high intra- (r=1.000, p<0.0001) and inter- (r=1.000, p=0.0004) session reproducibilities were achieved. Bland-Altman analysis showed limits of agreement from -0.11 to 0.04 (intra) and -0.15 to 0.9. |
| 4013 | Computer #82 |
Potential of NMR metabonomics of Small Intestinal Mucosa in assessing Marsh Grade in patients with Celiac Disease |
1Department of NMR & MRI Facility, All India Institute of Medical Sciences, New Delhi, India, 2Department of Gastroenterology and human Nutrition, All India Institute of Medical Sciences, New Delhi, India, 3Department of Pathology, All India Institute of Medical Sciences, New Delhi, India |
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This study illustrates the potential of proton NMR based metabonomics in determining biomarkers for assessing severity of villous abnormality in patients with celiac disease (CeD). CeD patients with Grade 3c showed significantly higher concentration of pyruvate, alanine and succinate compared to Grade 3b patients, suggesting more impaired oxidative phosphorylation in Grade 3c compared to Grade 3b patients. Increased acetoacetate in Grade 3c compared to Grade 3b patients indicated utilization of ketone bodies by intestinal mucosa for energy generation. Higher level of creatine seen in Grade 3c patients may probably be related to increased intestinal dysbiosis compared to Grade 3b patients. |
| 4014 | Computer #83 |
1H-MRS ultra-long echo time PRESS detects omega-3 fatty acids in vivo at 7T |
1High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 2Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria, 3MR Unit, Institute for Clinical and Experimental Medicine, Prague, Czech Republic, 4Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria |
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Omega-3 (n-3) fatty acids are essential to human health. However, the knowledge about their tissue concentrations is not well established. The spectral dispersion at 7T yields a sufficient spectral separation of n-3 (n-3 CH3) and non n-3 methyl (CH3) groups. Large differences in the T2 relaxation and J-modulation of outer triplet lines allowed for excellent separation of the n-3 CH3 signal and for estimation of its relative concentration in adipose tissue for the detection by 1H MR PRESS with TE of 1000ms. |
| 4015 | Computer #84 |
Broadband NOE for 7T 31-Phosphorous MRS of Human Brain |
1National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States |
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To further increase SNR of 7T Phosphorus (31P) MRS in human brain, Nuclear Overhauser Effect (NOE) has been utilized where WALTZ waveform was often applied during relaxation time with low RF peak power and long pulse width with inherent narrow bandwidth. At higher field with larger chemical shift dispersion of the protons, broadband saturation of protons is desirable. This study demonstrated the feasibility of broadband NOE at 7 Tesla for 31P MRS of human brain. |
| 4016 | Computer #85 |
Using Proton MR Spectroscopy and Quantitative Susceptibility Mapping (QSM) at 7 Tesla to Decipher Mitochondrial Membrane Protein–Associated Neurodegeneration (MPAN) |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany, 2Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, 3High Field MR Centre, Department of Biomedical Imaging and Image guided Therapy, Medical University of Vienna, Vienna, Austria, 4Department of Neurology and Center for Stroke Research Berlin, Charité Universitaetsmedizin, Berlin, Germany, 52nd Department of Neurology, Institute of Psychiatry and Neurology, Warsaw, Poland, 6Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Prague, Czech Republic, 7Institute of Neuroradiology, University Medicine Goettingen, Goettingen, Germany, 8Medical Image Analysis Center, Basel, Switzerland, 9Neurology Department, University of Kiel, Kiel, Germany |
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1H MR spectroscopy (MRS) in the white matter (WM) of the precentral region and quantitative susceptibility mapping (QSM) of basal ganglia acquired at 7 Tesla in patients (homozygotes), non-manifesting heterozygotes, and control subjects were used to investigate mitochondrial membrane protein-associated neurodegeneration (MPAN). MPAN is a rare, but severe disorder from the neurodegeneration with brain iron accumulation (NBIA) group. Comparison of results for the different subject groups showed no abnormalities in heterozygotes. In contrast, metabolic changes in patients detected by MRS, in particular an increase in glutamate, suggests an underlying mechanism for MPAN related to neurotransmission in corticospinal pathway. |
| 4017 | Computer #86 |
Investigating the effects of decoupling on in vivo 13C MRS to optimize acquisition in glycogen studies |
1Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, 2NIHR Nottingham Digestive Diseases Research Unit, University of Nottingham, Nottingham, United Kingdom |
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In this study the decoupling efficiency of in vivo 13C MRS measurements of glycogen levels was assessed. Due to SAR restrictions and surface coil decoupling field inhomogeneity, this study showed that short TR coupled spectroscopy provides improved SNR and better defined spectral parameters for fitting, whereas decoupled spectra reduces the number of averages in the same timeframe and runs the risk of varying residual coupling constants across a large field of view with inhomogeneous B2 |
| 4018 | Computer #87 |
Longitudinal relaxation time editing for acetylcarnitine detection with 1H-MRS |
1Radiology, Maastricht University Medical Center, Maastricht, Netherlands, 2Human Biology and Human Movement Sciences, Maastricht University Medical Center, Maastricht, Netherlands |
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The use of a long TE enables detection of acetylcarnitine with 1H-MRS. However, in (very) obese subjects, suppression of overlapping lipid resonances becomes problematic, even with long TE. We here show short T1 metabolites, such as lipids, can additionally be suppressed with a new T1 editing approach. |
| 4019 | Computer #88 |
Kinetic modelling of hyperpolarized13C-pyruvate metabolism in Canines using a model-based input function |
1Centre of Medical Imaging, UCL, London, United Kingdom, 2Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark, 3Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark, 4Centre for Medical Imaging, UCL, London, United Kingdom |
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Mathematical models based on kinetic parameters allow us to investigate 13C-pyruvate metabolism. Metabolic exchanges between pyruvate and its metabolites can differentiate benign from malignant tissue but their quantification is limited by the estimation of the arterial input function (AIF). This work suggests to model the AIF using a Gaussian pdf to account for the time pyruvate needs to travel and dispersion effects. The proposed AIF fits the measured data better than the commonly used box-car AIF, and is in agreement with the model-free formalism which approximates the kinetics using the ratios of AUC of the injected and product metabolites. |
| 4020 | Computer #89 |
Visualizing lactate in the ischemic hindleg of mice using localized proton 2D correlation spectroscopy (UHf-P-COSY) at ultrahigh field. |
1Radiology, Radboud University Nijmegen, Nijmegen, Netherlands |
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Lactate is associated with mitochondrial and neuromuscular diseases. Therefore, its methylene (CH2) and methyl (CH3) proton assignment is necessary in the skeletal muscle. In particular for understanding mechanisms associated with the skeletal muscle ischemia in rodents. Unambiguous detection of lactate resonances in the ischemic and/or hypoxic rodent muscle remains challenging, however, necessary for the assessment of treatment in the dysfunctional muscle of transgenic animals. In vivo lactate resonances remain hidden under lipid pool. However, by tuning spinecho delays in the localized 2D proton correlation sequence we are able to separate lactate CH2 and CH3 protons from the lipid resonances in the F1 dimension of the 2D-spectrum. |
| 4021 | Computer #90 |
Study of MS Tissue Injury and Repair with In Vivo MR Spectroscopy of Lipids and Proteins - First Results |
1Yale University, New Haven, CT, United States |
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Altered lipid and protein contents have been detected with MR spectroscopy in acute multiple sclerosis lesions and speculated to reflect de- and remyelination processes. To date, however, neither the metabolites involved nor their pathological relevance have been satisfactorily described. Hofmann et al. introduced an elegant concept for the separation of biochemicals of varying metabolic weight based on differences in T1 relaxation behavior (MRM 46, 2001). Here, we describe T1-encoded MR spectroscopy at 7 Tesla, the extraction of individual, spectroscopically overlapping lipid/protein signals by two-dimensional processing and initial applications to the study of the pathological processes associated to multiple sclerosis tissue injury and repair. |
| 4022 | Computer #91 |
Metabolic profiling of normal hepatocyte and hepatocarcinoma cell lines related to metastasis potentials by 1H NMR spectroscopy and chemometrics |
1Department of Electronic Science, Xiamen University, Xiamen, China, People's Republic of, 2The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, MengChao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, China, People's Republic of, 3Laboratory of Radiobiology, Fujian Provincial Tumor Hospital, Fuzhou, China, People's Republic of |
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To explore metabolic characteristics of hepatocarcinoma cell lines associated with different metastasis potentials, 1H NMR-based metabolomics conjugated with multivariate statistical analysis were performed to determine the molecular mechanisms of metastasis. Characteristic metabolites from both cell extracts and cultured medium were identified. Our results provide evidences that cells with different metastasis potentials exhibit different levels of glucose consumption, as well as the products of some intermediates of glycolysis. |
| 4023 | Computer #92 |
Simultaneous absolute quantitation of glutamate and GABA on highly resolved 2D constant time PRESS spectra using 2D FT with shared time domain data |
1Center for Environmental Measurement and Analysis, National Institute for Environmental Studies, Ibaraki, Japan |
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Absolute quantitation framework on highly resolved 2D CT-PRESS spectra with 1H decoupling was proposed for measurement of concentration of glutamate and GABA. Although peaks of these metabolites are clearly resolved on the spectra, long constant time delay (Tct) requires T2 correction. To overcome this, we proposed a fast T2 correction method using 2D FT with shared time domain data. After curve fitting of series of spectra with varied Tct's, we obtained series of peak volumes that can be expressed as an exponential decay of T2. In phantom experiments, we could measure the concentrations of glutamate and GABA by our method. |
| 4024 | Computer #93 |
Localized in-phase one-dimensional proton MRS |
1Electronic science, Xiamen University, Xiamen, China, People's Republic of |
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Magnetic resonance spectroscopy (MRS) is a powerful noninvasive tool in diagnoses, progressive monitoring, and studies of disease states of humans and animals. In this study, we present a MRS pulse sequence for localized one-dimensional in-phase proton MRS. The proposed pulse sequence can be utilized to reduce undesired broad resonances with short T2s and increasing signal intensity of J coupling metabolites. Moreover, it provides an approach of direct measurement of non-overlapping J coupling peaks at achievable arbitrary TEs and of their transverse relaxation times (T2). |
| 4025 | Computer #94 |
Grey and white matter signal separation in the single voxel NMR spectroscopy at 7T |
1Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany, 2Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands, 3Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, Netherlands |
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GABA spectroscopy has two potential confounds widely ignored by the spectroscopic community: 1) a potential 5-10Hz frequency shift between grey and white matter shown in imaging experiment and 2) the fact that the GABA is circa 9 times more concentrated in grey matter. To investigate whether these confounds could affect GABA spectroscopy at 7T, we compute grey and white matter lineshapes by frequency mapping. We found a slight frequency shift and lineshape which can be ignored. Hence, we conclude that we can probably safely use a single lineshape for fitting using LCModel. |
| 4026 | Computer #95 |
Potential of 3T fMRS to detect dynamic changes of glutamate related to activation in visual cortex |
1NMR Group, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Charité - Berlin Center for Advanced Neuroimaging (BCAN), Berlin, Germany |
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Dynamic changes of metabolite concentrations in the human brain have been successfully detected in response to stimulus at 7T. The present study focus on characterize the detection limits at 3T. 20min fMRS paradigm alternated 5min intervals with stimulus OFF/ON/OFF/ON. A significant intra-individual increase in glutamate+glutamine (Glx) was found in the group analysis (1.83%, p = 0.017). The cross-subjects averaged time course also indicated 1.98% concentration increase during the ON periods. A direct correlation between subtle changes of Glx concentrations and the application of a visual stimulus could be shown consistent with reports from ultra-high field studies. |
| 4027 | Computer #96 |
GABA+ levels in postmenopausal women with mild-to-moderate depression: A Preliminary Study |
1Shandong Medical Imaging Research Institute, Jinan, China, People's Republic of, 2Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China, People's Republic of, 3Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China, People's Republic of, 4Shandong Chest Hospital, Jinan, China, People's Republic of, 5Philips Healthcare, Shanghai, China, People's Republic of, 6QiLu Hospital of Shandong University, Jina, China, People's Republic of, 7Shandong Medical Imaging Research Institute, Shandong University, Jinan, China, People's Republic of, 8Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA, Baltimore, MD, United States, 9FM Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA, Baltimore, MD, United States |
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The present study hypothesized that the GABA levels would be lower in postmenopausal women with mild-to-moderate depression. We investigate the cerebral GABA levels in postmenopausal women using the edited MRS technique MEGA-PRESS. 18 postmenopausal women with mild-to-moderate depression and 11 healthy controls with the age- and body index-, educationally matched were enrolled. GABA+ levels were quantified in the anterior cingulate cortex/medial prefrontal cortex (ACC/mPFC) and the posterior cingulated cortex (PCC). Water-scaled GABA+ levels were significantly lower in the ACC/mPFC regions of patients group than in healthy controls, which suggesting that dysfunctional GABAergic system may be involved in depression in postmenopausal women. |
| Exhibition Hall | Wednesday, May 11, 2016: 16:00 - 17:00 |
| 4028 | Computer #1 |
Simultaneous assessment of cerebral iron load, as estimated by Quantitative Susceptibility Mapping, and Amyloid-β plaque density, as measured by 18F-Flutametamol, in Super-agers |
1Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland, 2F.M. Kirby center for Functional Brain Imaging, Kennedy Krieger Institute and Johns Hopkins School of Medicine, Baltimore, MD, United States, 3Division of Nuclear Medicine, University of Zurich, Zurich, Switzerland |
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We investigated “super-agers” (a minority of elderly subjects that display significantly higher cognitive performance levels) for the interaction of Aβ-plaque burden and iron load, using Quantitative Susceptibility Mapping and simultaneous 18F-Flutametamol measures in the PET-MR. We found significant increased iron load in the putamen and caudate nucleus of subjects with a high Aβ-plaque burden, but no regional correlations between the two markers in gray matter. This suggests that while super-agers are affected by common age-related brain pathologies, such as cortical Aβ-plaque burden and increased striatal iron load, these might exert less neurotoxic damage. |
| 4029 | Computer #2 |
The glutamine and glutamate complex measured by functional MRS alters during a face-name association task in patients with MCI and AD |
1Department of Radiology, Kyung Hee University Hospital at Gangdong, Kyung Hee University, Seoul, Korea, Republic of, 2Department of Biomedical Engineering, The Catholic University of Korea, Seoul, Korea, Republic of, 3Department of Neurology, Kyung Hee University Hospital at Gangdong, Kyung Hee University, Seoul, Korea, Republic of, 4Department of Mental Health, Kyung Hee University Hospital, Kyung Hee University, Seoul, Korea, Republic of, 5Department of Radiology, Kyung Hee University Hospital, Kyung Hee University, Seoul, Korea, Republic of |
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To investigate the metabolite changes in subjects with AD, MCI, and cognitively normal (CN) elderly during a memory task using dynamic MRS at a 3T MRI system, we included 95 subjects who included: 23 young normal control (YC), 24 cognitively normal (CN) elderly, 24 aMCI, and 24 mild and probable AD. The functional MRS data were measured during the face-name association task with the stimulation paradigm of fixation, novel, and repeat conditions. The fMRS data were analyzed using the LCModel software. Glx was altered during the stimulation conditions, which can be used in neuronal dysfunction for a patient with dementia. |
| 4030 | Computer #3 |
Abnormal Grey Matter Arteriolar Cerebral Blood Volume and its Association with the Presence of E4 Allele of the Apolipoprotein E (APOE) Gene in Elderly Subjects at Risk for Alzheimer’s Disease (AD) |
1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 2Neurosection, Div. of MRI Research, Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States, 4Institute for Biomedical Engineering, University of Zürich and ETH Zürich, Zürich, Switzerland, 5Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich and ETH Zürich, Zürich, Switzerland, 6Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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Cerebrovascular dysfunction has been associated with mild-cognitive-impairment (MCI) and Alzheimer’s Disease (AD). Recent animal studies in aging show that abnormalities in pial arteries and arterioles start before other blood vessels and blood flow are affected. We show that cerebral-blood-volume of pial arteries and arterioles (CBVa), measured with the inflow-based vascular-space-occupancy (iVASO) MRI, is significantly altered in various brain regions in MCI patients compared to healthy elderly controls. CBVa in the orbitofrontal cortex significantly correlated with APOE-e4 carrier-status, the major genetic risk factor for sporadic AD. Our results suggest CBVa as a potential biomarker at an early stage of the disease. |
| 4031 | Computer #4 |
Sildenafil improves vascular and metabolic function in patients with Alzheimer’s Disease |
1Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, 3Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 4Avid Radiopharmaceuticals, Inc., Philadelphia, PA, United States, 5Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States |
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Alzheimer’s disease (AD) is the leading cause of degenerative dementia in the aging population. Patients with AD have alterations in cerebral hemodynamic function. Therefore, improved cerebrovascular function may be an attractive goal for pharmaceutical intervention in AD. Our study applied several novel non-invasive MRI techniques to investigate the alterations of CBF, cerebral metabolic rate of oxygen (CMRO2) and cerebrovascular reactivity (CVR) after a single dose of sildenafil administration in order to assess its physiological effects in AD patients. Our data suggest that a single dose of sildenafil improves cerebral hemodynamic function and increases cerebral oxygen metabolism in patients with AD. |
| 4032 | Computer #5 |
Multi-Parametric Imaging Assessment of Alzheimer’s Disease Pathology |
1Radiology, Massachusetts General Hospital, Boston, MA, United States, 2A. A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, 3Neurology, Massachusetts General Hospital, Boston, MA, United States |
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The purpose of this study was to find associations between metabolites measures by MRS and glucose metabolism using FDG PET and cerebral blood flow (CBF) measured by ASL MRI in the assessment of Alzheimer’s Disease. Our study shows an association between increased myo-inositol, a marker of glial inflammation, and hypo-metabolism measured by FDG as well hypo-perfusion measured by ASL. Liner regression analysis revealed that creatine, a marker of altered energy metabolism positively correlated with increased glucose uptake by FDG PET. Increased levels of glutamate+glutamine (contributing to excitotoxicity) were related to decreased metabolic activity by PET and decreased CBF. |
| 4033 | Computer #6 |
Functional connectome architecture of Alzheimer’s disease, mild cognitive impairment and behavioral variant of frontotemporal dementia: a graph analysis study. |
1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 3Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy |
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This is a graph analysis study applying a new parcellation approach, which combines the need for equal sized nodes with respecting brain anatomy, on resting state fMRI data from a population of 247 patients with neurodegenerative cognitive impairment (early [EO] and late onset [LO] Alzheimer’s disease (AD), behavioural frontotemporal dementia [bvFTD], mild cognitive impairment [MCI]) and 86 controls. Compared to other groups, AD patients showed disrupted global network connectivity, while MCI had specific regional changes, suggesting that graph-analysis is promising to detect early features of neurodegeneration. Global and regional graph network properties were able to distinguish EOAD and bvFTD. |
| 4034 | Computer #7 |
Investigating the correspondence of clinical diagnostic grouping with underlying neurobiological and phenotypic clusters using unsupervised learning: An application to the Alzheimer’s spectrum |
1Electrical and Computer Engineering, AU MRI Research Center, Auburn, AL, United States, 2Medical Electronics, Dayananda Sagar College of Engineering, Bangalore, India, 3Psychology, Auburn University, Auburn, AL, United States, 4Alabama Advanced Imaging Consortium, Auburn University and University of Alabama Birmingham, Auburn, AL, United States |
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Many brain-based disorders are traditionally diagnosed based on clinical interviews and behavioral assessments. Using Alzheimer’s spectrum (i.e. mild cognitive impairment [MCI] and Alzheimer’s disease [AD]) as a test case, we investigated whether clinical diagnostic grouping is grounded in underlying neurobiological and phenotypic clusters. In order to do so, three unsupervised learning methods were applied on resting-state fMRI connectivity measures obtained from subjects with MCI and AD. High similarity was achieved between connectivity and phenotypic clusters while similarity was low with clinical diagnosis. It shows that neurobiological and phenotypic markers could be used to improve the precision of clinical diagnosis. |
| 4035 | Computer #8 |
Imaging vascular alterations in a mouse model of Down’s syndrome using magnetic resonance angiography with tensor-based morphometry |
1Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom, 2Centre for Medical Image Computing, University College London, London, United Kingdom, 3National Institite for Medical Research, London, United Kingdom, 4Institute of Neurology, University College London, London, United Kingdom |
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Magnetic resonance angiography (MRA) is an established MRI technique for visualising the cerebral vasculature. Interpretation of MR angiograms is often reliant on visual inspection of the data;1 however, it is possible to misinterpret flow artefacts (e.g. signal voids) as vascular alterations.2 In this work, we have used a novel combination of MRA and advanced registration as well as statistical algorithms to explore vascular alterations in the Tc1 mouse model of Down’s syndrome. We identified operator-independent local disturbances in the vascular architecture, which supports previous work in this mouse model as well as observations in the wider DS population. |
| 4036 | Computer #9 |
Probing white matter abnormalities in preclinical and early Alzheimer’s disease |
1Mallinckrodt Institute of Radiology, Washington University in St. Louis, St. Louis, MO, United States, 2Knight Alzheimer's Disease Research Center, St. Louis, MO, United States, 3Obstetrics and Gynecology, Washington University in St. Louis, St. Louis, MO, United States, 4Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States, 5Neurology, Washington University in St. Louis, St. Louis, MO, United States, 6Knight Alzheimer’s Disease Research Center, St. Louis, MO, United States, 7Neurosurgery, Washington University in St. Louis, St. Louis, MO, United States |
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Robust neuroimaging biomarker sensitive to the early white matter abnormalities could provide novel insights into the pathogenesis of Alzheimer’s disease (AD), and serve as surrogate measures for disease progression. We demonstrated that novel DBSI white matter abnormality biomarkers strongly correlate with invasive CSF measures of neuronal injuries, and provide specific preclinical measures of WM abnormalities for early diagnostics and accurate assessment of disease-modifying therapies targeting neuro-protection in AD. |
| 4037 | Computer #10 |
White matter lesion volume does not affect the relationship between CSF Aβ42 and cerebral amyloid deposition assessed with PET |
1Diagnostic Radiology, Lund University, Lund, Sweden, 2Memory Clinic, Lund University, Lund, Sweden, 3The Sahlgrenska Academy at University of Gothenburg, Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Gothenburg, Sweden |
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White matter lesions (WML) are abundant in the elderly and even more so in Alzheimer’s disease (AD). Previous studies indicate that WML affect the level of cerebrospinal fluid (CSF) Aβ42 and this in turn might affect the validity of CSF Aβ42 as biomarker of the pathological hallmark of AD, namely cerebral amyloid deposition. Therefore, we studied the influence of WML on the association between CSF Aβ42 and amyloid deposition measured with [18F]-flutemetamol positron emission tomography (PET). |
| 4038 | Computer #11 |
Voxel-Based Analysis of Cerebral Perfusion in Subcortical Ischemic Vascular Dementia and Alzheimer’s Disease Dementia: a Multi-Parametric Multi-TI Arterial-Spin-Labeling Study |
1Shandong Medical Imaging Research Institute, Shandong University, Jinan, China, People's Republic of, 2Siemens Healthcare, MR Collaborations NE Asia, Beijing, China, People's Republic of, 3Shandong provincial Hospital, Shandong University, Jinan, China, People's Republic of, 4Siemens Healthcare, Application Development, Erlangen, Germany |
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This study aims to present the feasibility of multi-TI (mTI)-ASL in distinguishing between AD and SIVD patients in cerebral perfusion. Nineteen SIVD subjects, twelve AD subjects, and ten controls were included in the study. There was no significant difference in CBF between SIVD and HCs, and between SIVD and AD patients. However, significant differences of BAT were detected among all three groups. The mTI-ASL could evaluate the cerebral perfusion of AD and SIVD patients. Compared with CBF, the BAT could better detect perfusion differences and demonstrated better efficiency. |
| 4039 | Computer #12 |
DynamicDysfunctionof DMN in AD and MCI:a Time Point-Based Network Analysis |
1MR Collaborations NE Asia, Siemens Healthcare, Beijing, China, People's Republic of, 2Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China, People's Republic of |
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In recent years, the study of dynamic changes within brain functional networkshas become a trend topic in the fields of neuroscience and neuroradiology. In this study, we proposed a time-pointbased analysis method to search for dynamic pattern changes in normal controls, AD and two MCI stages.We aim to investigate whether the DMN deficit we observed in previous studiesis related to changes of activity frequency of micro-state network condition.The results show that the dynamic patterns obtained by the time point-based analysis could detect several DMN micro-states and the frequency of the appearance of these micro-states changes during the progress of cognitive impairment. |
| 4040 | Computer #13 |
Temperature effects in post mortem structural MRI of human brain in situ |
1Medical Radiation Physics, Lund University, Lund, Sweden, 2Cognitive Neurology, Göttingen University Medical Center, Göttingen, Germany, 3Neuropathology, Göttingen University Medical Center, Göttingen, Germany |
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Structural 3D MRI and FLASH-based mapping of T1 and magnetization transfer (MT) at 3T was performed in situ on 11 subjects with probable Creutzfeldt-Jacob disease prior to autopsy. The mean diffusivity in ventricles yielded temperatures between 6°C and 29°C. T1 contrast in the deep brain decreased with temperature and vanished under refrigerated conditions. T1 of gray matter lowered towards the normal white matter’s T1 which did not change. The MT saturation was generally independent of temperature, except in normal WM below 13°C. Above 13°C, MT maps yield a high contrast and can be used for quantitative assessment of structural changes. |
| 4041 | Computer #14 |
Histological correlates of MRI contrast in patients with Alzheimer’s Disease |
1Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Department of Anatomy and Neurosciences, VU University Medical Center, Amsterdam, Netherlands, 3Human Genetics, Leiden University Medical Center, Leiden, Netherlands |
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Investigating the histological correlates of MRI contrasts in patients with Alzheimer’s disease (AD) will give more insight into the pathological correlates of T2* and SWI. Using 7T MRI and histology of post-mortem brain tissue we showed that the frontal cortex of AD patients has a different imaging phenotype compared to non-demented controls, which spatially correlates to changes in iron deposition and grey matter myelin organization Most importantly, within the AD group the early-onset AD patients are distinguishable on MRI from the late-onset AD patients, and these differences are mirrored in the underlying pathology of these AD subtypes. |
| 4042 | Computer #15 |
Probing the effects of elevated glucose level on the integrity of white matter in Alzheimer’s disease using diffusion kurtosis imaging |
1Radiology Department, the First Affiliated Hospital of Dalian Medical University, Dalian, China, People's Republic of, 2GE Healthcare MR Research China, BeiJing, China, People's Republic of |
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AD concomitant with hyperglycemia is commonly observed during clinical work, and it was known that AD and disorder of glucose metabolism are related.However, the factor of glucose level in AD patients have not yet been taken into consideration in the past studies, which might be of clinical significance in learning the AD progression. In this work, DKI is used to probe the likely effects of elevated glucose level in the white matter microstructure of AD patients. |
| 4043 | Computer #16 |
The effect of physical exercise on cerebral blood flow in Alzheimer’s disease |
1Department of Radiology, UMC Utrecht, Utrecht, Netherlands, 2Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark, 3Danish Dementia Research Centre, Department of Neurology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark, 4Musculoskeletal Rehabilitation Research Unit and Institute of Sports Medicine, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark |
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The purpose of this study was to determine the effect of moderate-to-high-intensity aerobic exercise on cerebral blood flow in patients with Alzheimer’s disease (AD). In the ADEX trial, patients with mild to moderate AD participated in aerobic exercise for 16 weeks. Pulsed Arterial Spin Labeling was performed at baseline and at 16 weeks. CBF in the anterior cingulate cortex was significantly lower at 16 weeks in the control group, but it remained unchanged in the intervention group. Our results suggest that even brains affected by mild to moderate Alzheimer’s disease may still benefit from regular exercise. |
| 4044 | Computer #17 |
TDP43 correlates of amygdala volume in aging with ex-vivo MRI |
1Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States, 2Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, United States |
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Transactive response DNA-binding protein 43 (TDP43) pathology was the primary protein abnormality in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Recent findings showed that TDP43 pathology is common in old age and strongly associated with cognition, cognitive decline and increased risk of dementia beyond the contributions of other age-related neuropathologies. TDP43 pathology in aging is mainly found in the medial temporal lobes with the being one of the first regions to be affected. The purpose of this project was to study associations of TDP43 in aging with amygdalar volume for the first time in a large community cohort. |
| 4045 | Computer #18 |
Gender Based Analyses of Cortical Thickness and Structural Networks Connectivity in Parkinson’s Disease |
1Division of Translational Medicine, Sidra Medical and Research Center, Doha, Qatar, 2Department of Medical physics, University college of Landon, Landon, United Kingdom, 3Center for Biomedical Engineering, Indian institute of Technology, Delhi, India, 4Department of diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, MD, United States, 5Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States |
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We evaluated the gender based differences in cortical thickness and structural brain network connectivity in PD patients. Significantly reduced cortical thicknesses and disrupted structural networks connectivity appeared in PD males compared to PD females suggestive of more brain tissue changes in PD males than PD females. These male-specific cortical thickness changes and disrupted structural networks connectivity may contribute to or derive from physiological and genetically differences between males and females and may have significant implications in diagnosing and treating PD among the gender. |
| 4046 | Computer #19 |
Investigating pathology-related functional connectivity in cognitively normal super-agers |
1Psychiatric Research, University of Zurich, Zurich, Switzerland, 2F.M. Kirby center for Functional Brain Imaging, Kennedy Krieger Institute and Johns Hopkins School of Medicine, Baltimore, MD, United States, 3Division of Nuclear Medicine, University of Zurich, Zurich, Switzerland |
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To investigate early stages of preclinical Alzheimer’s, this study investigates the functional connectivity of 25 cognitively healthy elderly participants (“super agers”) in relation to cortical iron (using QSM) and cortical amyloid-beta load (18F-Flutemetamol PET). Functional connectivity analysis with the posterior cingulate cortex (PCC) as a seed found significant regional and temporal overlaps in primary DMN regions for groups with high iron and high amyloid. Despite the network synchronicities, a contrast between high iron and high amyloid networks found significant FC differences between the PCC, precuneus, hippocampus and parahippocampus which are DMN connections known to be affected by Aß-burden. |
| 4047 | Computer #20 |
Deformation Based Classification of Alzheimer’s Disease |
1Computer Science, University of Copenhagen, Copenhagen, Denmark |
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Effective and accurate diagnosis of Alzheimer’s disease (AD) purely based on structural magnetic resonance imaging (MRI) is a very pertinent clinical problem. We present a simple but highly accurate registration-based method to discriminate between the three classes of healthy controls (HC), mild cognitively impaired (MCI) and AD. The method uses the norm of the tangent space of the deformation in a K-nearest neighbor KNN classifier. The result show that for 60 subjects, 20 in each class using n-fold cross-validation an overall accuracy of 81.6% with 75% for HC, 85% MCI and 85% for AD. |
| 4048 | Computer #21 |
A follow-up study of hippocampal subfield atrophy in mild cognitive impairment with automatic segment method |
1RADIOLOGY, PEKING UNIVERSITY THIRD HOSPITAL, BEIJING, China, People's Republic of |
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Mild cognitive impairment (MCI) is often considered as an intermediate stage between normal aging and dementia, as reflected by a higher rate of conversion to clinical Alzheimer’s disease (AD) than in the normal elderly population. The hippocampal formation is a complex brain region with a primary role in memory function and vulnerable to neurodegenerative diseases. The aim of this research is to investigate the atrophy feature of hippocampal subfield and follow up the changes of hippocampal subfield in about two years by using automatic segmentation tool in patients with MCI.Our results suggest that compared to ICV, hippocampal subfield could be a more sensitive to detect cerebral changes of MCI. CA1, CA3 and left entorhinal cortex may be main subfields involved during MCI stage. Volumes of hippocampal subfield decreased in MCI patients and were positive correlation with clinical scores. There were also decreases in volumes of hippocampal subfield in MCI patients with the progress of the disease. |
| 4049 | Computer #22 |
4D Flow MRI for assessing cerebral venous flow, a potential surrogate marker for capillary pulsatility in Alzheimer’s disease |
1Medical Physics, University of Wisconsin Madison, Madison, WI, United States, 2Radiology, University of Wisconsin Madison, Madison, WI, United States, 3Medicine, University of Wisconsin Madison, Madison, WI, United States |
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Cerebral arteries are often morphologically altered and dysfunctional in Alzheimer’s disease. In this study, 4D flow MRI was used to assess cerebral venous flow, particularly mean blood flow and pulsatility index in patients with AD, and in healthy age matched controls. We found a statistically significant increase in pulsatility index and decrease in mean flow for the AD in most venous segments. With the large volume coverage and high temporal and spatial resolution, 4D flow MRI can provide additional biomarkers of vascular health that can contribute to the identifying patients who could benefit from interventions to improve circulatory system functions. |
| 4050 | Computer #23 |
Evaluation of blood brain barrier permeability in Alzheimer’s disease with DCE-MRI |
1Imanova, London, United Kingdom, 2Klarismo, London, United Kingdom, 3MIT Sloan School of Management, Cambridge, MA, United States, 4GSK, Brentford, United Kingdom, 5Imperial College London, London, United Kingdom |
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DCE 3T MRI data acquired from 6 subjects with previous diagnoses of AD, 2 subjects with vascular dementia, and 7 healthy controls group-matched for age and gender. Radiofrequency transmit (B1) field corrected Gd concentration values were calculated via dual-temporal resolution dynamic T1 mapping during and over 45 minutes post rapid Gd infusion. The extended Tofts model was used to determine the volume and rate transfer constants of BBB permeability in 11 regions of interest. No differences were detected between groups, implying BBB leakage in AD is slower than detectable in this experiment, or that BBB permeability in AD is moderated by an active transport mechanism. |
| 4051 | Computer #24 |
Quantitative Susceptibility Mapping in Alzheimer’s Disease using Joint background-field removal and segmentation-Enhanced Dipole Inversion |
1Philips Research Europe, Hamburg, Germany, 2University of Sheffield, Sheffield, United Kingdom |
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Quantitative Susceptibility Mapping (QSM) is used to study the deep gray-matter nuclei of patients with Alzheimer’s Disease (AD) and healthy control subjects. QSM is performed using “Joint background-field removal and segmentation-Enhanced Dipole Inversion” (JEDI), which leverages the information from automated model-based segmentation and allows the compact single-step formulation of the ill-posed inversion problem of QSM. The tissue magnetic susceptibility shows a trend for increase in the amygdala and the putamen of AD patients as compared to healthy control subjects, in agreement with previous studies. |
| Exhibition Hall | Wednesday, May 11, 2016: 16:00 - 17:00 |
| 4052 | Computer #25 |
Effect of patient motion on the visibility of small veins in T2*w imaging: A simulation experiment with implications for the study of the central-vein-sign (CVS) theory in MS |
1Buffalo Neuroimaging Analysis Center, Department of Neurology,Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States, 2High Field Magnetic Resonance Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 3MRI Molecular and Translational Research Center, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States |
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FLAIR* is a fusion of T2-FLAIR and 3D-T2*w images and it is used to assess the central-vein-sign, a recent promising research direction in MRI-based study of Multiple Sclerosis. However in this experiment we show that researchers should be aware that slight patient movement during acquisition can produce blurring effect in 3D-T2*w images. This subtle artifact can mask small vessels even in case which the overall quality of the image is not substantially degraded. |
| 4053 | Computer #26 |
Combined Anatomic and Functional Connectivity Metric for Tracking Disease Progression in MS |
1Imaging Institute, Cleveland Clinic, Cleveland, OH, United States, 2Neurologic Institute, Cleveland Clinic, Cleveland, OH, United States |
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Based on the observation that anatomic and functional connectivity measures in multiple sclerosis (MS) are correlated, but not highly correlated, we propose to combine these metrics into an imaging based measure of disease progression. We show that this metric is sensitive to disease progression in a cohort of MS patients over a time period of one year. |
| 4054 | Computer #27 |
Assessment of ferritin in the multiple sclerosis brain using temperature induced R2* changes |
1Department of Neurology, Medical University of Graz, Graz, Austria, 2Blizard Institute (Neuroscience), Queen Mary University of London, London, United Kingdom, 3Barts Health NHS Trust, Emergency Care and Acute Medicine Clinical Academic Group (Neuroscience), London, United Kingdom |
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Evidence for a possible role of iron in the pathogenesis and progression of multiple sclerosis (MS) has raised interest in iron mapping techniques. However, current approaches are not reliable in white matter because of the diamagnetic properties of myelin. We recently proposed a new method for iron mapping which is based on the temperature dependency of the paramagnetic susceptibility. Here, the temperature coefficient of R2* (TcR2*) as a measure of iron content was assessed in three post-mortem MS brain samples. Validation of TcR2* mapping was done with immunohistochemistry using cell counting on ferritin light-chain stains. |
| 4055 | Computer #28 |
Longitudinal mcDESPOT Shows Contrasting Patterns of Change in Multiple Sclerosis and Neuromyelitis Optica Cervical Cord |
1Neuroimaging, King's College London, London, United Kingdom, 2Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 3Medicine, University of British Columbia, Vancouver, BC, Canada, 4Radiology/UBC MS/MRI Research Group, University of British Columbia, Vancouver, BC, Canada |
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Neuromyelitis optica (NMO) severely affects the optic nerves and spinal cord and shares features with multiple sclerosis (MS). Ongoing diffuse neurodegeneration, however, is thought to be absent in NMO between relapses. We collected cervical cord mcDESPOT at baseline and one-year follow-up in patients and matched controls. While there were no significant changes in controls and MS patients, the NMO group showed a loss of cord volume, decrease in T1 and increase in myelin water fraction. We hypothesize that continuing atrophy in lesioned areas reduces the amount of damaged tissue relative to healthy tissue, and is responsible for the observed changes. |
| 4056 | Computer #29 |
White Matter Water Content in Multiple Sclerosis and Neuromyelitis Optica |
1Radiology, University of British Columbia, Vancouver, BC, Canada, 2Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 3Medicine, University of British Columbia, Vancouver, BC, Canada |
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Multiple sclerosis (MS) and neuromyelitis optica (NMO) are both autoimmune diseases of the central nervous system. Normal appearing white matter is known to be affected by diffuse tissue damage in MS whereas damage in NMO is thought to be restricted to acute lesions. Surprisingly, in this study, water content within whole white matter and white matter tracts of subjects with neuromyelitis optica (NMO) was found to be higher than in healthy matched controls and similar to MS. Both NMO and MS lesions had a higher water content compared to normal appearing white matter. |
| 4057 | Computer #30 |
A randomized controlled trial on the efficacy of cognitive training in MS reveals functional connectivity changes |
1IRCCS, Don Gnocchi Foundation, Milan, Italy, 2Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy, 3Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton, United Kingdom, 4Neuroimaging Laboratory, University of Campinas, Cidade Universitária, Campinas, Brazil, 5Psychology Department, Royal Holloway, University of London, Egham, United Kingdom, 6Department of Neurology, Brighton and Sussex University Hospitals NHS Trust, Brighton, United Kingdom |
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We investigated the resting-state functional connectivity (FC) changes induced after 6 weeks of computerised, home-based cognitive rehabilitation in patients with multiple sclerosis (MS) in a randomized controlled trial. The intervention and control groups were evaluated at baseline (T1), after a 6-week intervention period (T2) and a 12-week follow-up period (T3). Out of the 94 regions investigated, many memory-, attention- and motor-related areas strengthened their FC at T2 and T3 in the intervention group. This study supports the hypothesis that this cognitive rehabilitation is a feasible and effective approach in patients with MS and confirms that rfMRI is a useful tool for mapping plastic changes. |
| 4058 | Computer #31 |
Quantitative T2 mapping detects pathology in normal-appearing brain regions of relapsing-remitting MS patients |
1Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States, 2The Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, 3Department of Radiology, New York University School of Medicine, New York, NY, United States |
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Accurate quantification of T2 values in vivo is a long-standing challenge hampered by the inherent inaccuracy associated with rapid multi-SE sequences. This inaccuracy is, moreover, not constant and depends on both the pulse sequence scheme and parameter-set employed, resulting in different vendors or scanners yielding different results! We used a recently developed novel T2 mapping technique, the EMC algorithm, to quantify T2 changes in different brain regions of MS patients. Our results demonstrate that the robustness of the EMC approach allows the detection of subtle, but statistically significant T2 differences in normal appearing brain regions for MS patients. |
| 4059 | Computer #32 |
Ultra-high Resolution MRSI of Multiple Sclerosis at 7T |
1MRCE, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 2Department of Neurology, Medical University of Vienna, Vienna, Austria, 3Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria |
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In this study fourteen MS patients were measured with an FID-based MRSI sequence at 7T with resolutions of 64x64 and 100x100. Metabolic maps of total NAA, total Choline, total Creatine, and myo-Inositol were compared to FLAIR images. All patients had lesions with decreased tNAA, and eight had increased myo-Inositol levels. However, not all lesions showed decreased tNAA values. Two patients showed decreased tNAA levels with no visible lesion on the FLAIR image. In average, a decrease of 26% in tNAA and an increase of 42% in myo-Inositol were observed in comparison to normal appearing white matter. |
| 4060 | Computer #33 |
BA 4p BOLD response profile distinguishes low and high MS morbidity |
1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom, 2Department of Diagnostic Radiology, Faculty of Applied Medical Science, KAU, Jeddah, Saudi Arabia, 3Department of Neurosciences, Ophthalmology and Genetics, University of Genoa, Genoa, Italy, 4Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy, 5Brain Connectivity Center, C.Mondino National Neurological Institute, Pavia, Italy, Pavia, Italy, 6Wellcome Centre for Imaging Neuroscience, UCL, Institute of Neurology, London, United Kingdom, 7NMR Research Unit, Department of Brain Repair and Rehabilitation, Queen Square MS Centre, UCL Institute of Neurology, London, United Kingdom |
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This study investigates how multiple sclerosis (MS) selectively affects regional BOLD response to variable grip forces (GF). It is known that the anterior and posterior BA4 areas are anatomically and functionally distinguishable – and that in healthy subjects there are linear and non-linear BOLD response components. After modelling BOLD responses with a polynomial expansion of the applied GF during task, we showed that in BA4a MS subjects respond like healthy subjects. BOLD response in BA4p, instead, was altered in MS, with those with greatest disability showing the greatest deviations from the non-linear profile of the healthy response. |
| 4061 | Computer #34 |
Functional cognitive control load in multiple sclerosis |
1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 3Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy |
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In this study, we investigated behavioral and functional MRI (fMRI) correlates of a N-back task in 72 patients with multiple sclerosis (MS). We found a load-dependent alteration of executive network recruitment, varying according to the disease phenotype. Increased recruitment of frontal regions was associated to the early phase of MS. Conversely, the modulation of regions belonging to the default mode network was more evident in patients with long-lasting disease and was related to the global cognitive profile, suggesting an increased need of cognitive resources to cope with task-demand. |
| 4062 | Computer #35 |
Formation of transient and persistent multiple sclerosis lesions: serial follow-up with quantitative MR imaging and spectroscopy |
1Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States, 2Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, NY, United States, 3Chemical Physics, Weizmann Institute of Science, Rehovot, Israel, 4Neurology, New York University Langone Medical Center, New York, NY, United States |
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Using MR imaging and proton spectroscopy, we follow the evolution of transient and persistent multiple sclerosis lesions from pre-lesional state to long-term (over 2 years post-formation) status. The main finding was that the sharp drop in N-acetyl-aspartate associated with the formation of an acute lesion was reversible in resolving, but not in persisting black holes, substantiating the idea that transient new lesions revert to pre-lesional axonal state. The additional findings were a decrease in creatine after the appearance of a persisting lesion and the lack of metabolic differences between pre-lesional tissue giving rise to resolving versus persisting lesions. |
| 4063 | Computer #36 |
Assessment of grey matter cortical lesions in Multiple Sclerosis using high resolution ASL at 7T |
1Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, 2Nottingham University Hospital, University of Nottingham, Nottingham, United Kingdom |
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Grey matter cortical lesions have been associated with physical disability, cognitive impairment and fatigue in Multiple Sclerosis. Only one previous study has assessed cerebral blood flow (CBF) and cerebral blood volume (CBV) within cortical lesions. Here we use high spatial resolution 7T FAIR TrueFISP ASL to assess the perfusion in grey matter cortical lesions and compare this to surrounding normal appearing grey matter. Cortical lesions showed a significant 32% reduction in perfusion signal compared to normal appearing grey matter. This ASL method can be used to evaluate longitudinal perfusion changes in new and chronic cortical lesions. |
| 4064 | Computer #37 |
Energy dysregulation and neuro-axonal dysfunction in multiple sclerosis measured in-vivo with diffusion-weighted spectroscopy |
1Brain and Spine Institute, INSERM U1127, Sorbonne Universités, UPMC, CHU Pitié-Salpêtrière, Paris, France, 2Brain and Spine Institute, Center for Neuroimaging Research (CENIR), CHU Pitié-Salpêtrière, Paris, France, 3C.J. Gorter Center for High Field MRI, Radiology, Leiden University Medical Center, Leiden, Netherlands |
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Diffusion-weighted spectroscopy (DWS), allowing to measure in-vivo the diffusion properties of endogenous intracellular metabolites such as total N-acetyl-aspartate (tNAA) and total creatine (tCr), offers the opportunity to explore the early phase of neuronal structural damage and energetic mismatch in multiple sclerosis (MS). We compared the apparent diffusion coefficient (ADC) of tNAA and tCr in 25 patients with MS and 20 healthy volunteers, and found a reduced diffusivity of both metabolites in patients, both in the corona radiate and in the thalami. These results may reflect an ongoing neuro-axonal damage and a simultaneous energy dysregulation affecting neurons and/or glial cells in MS. |
| 4065 | Computer #38 |
N-acetyl aspartate predicts disease severity in an animal model of multiple sclerosis (MS) |
1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom, 2Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, University College London, London, United Kingdom, 3Leonard Wolfson Experimental Neurology Centre, UCL Institute of Neurology, University College London, London, United Kingdom, 4Department of Neuroinflammation, Queen Square MS Centre, UCL Institute of Neurology, University College London, London, United Kingdom, 5Department of Brain Repair and Rehabilitation, Queen Square MS Centre, UCL Institute of Neurology, University College London, London, United Kingdom |
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EAE, an animal model of MS, can be investigated with MR to address the clinical need to understand mechanisms of the MS disease course. Longitudinal MR studies with EAE are currently under-explored. This study investigated longitudinal changes in metabolite concentrations and lesion development, in relation to neurological deficits in EAE, using 9.4T MRI and 1H-MRS. Five time-points of EAE disease progression were assessed. The results suggest that before visible signs of neurological deficits, higher [NAA] predicts the severity of late-stage neurological deficits in EAE. Considering NAA is predominantly associated with neuronal mitochondria, this may reflect relevant pathological processes in MS. |
| 4066 | Computer #39 |
Longitudinal follow-up of chronic multiple sclerosis lesions with quantitative MR imaging and partial volume-corrected proton MR spectroscopy |
1Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States, 2Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, NY, United States, 3Chemical Physics, Weizmann Institute of Science, Rehovot, Israel, 4Neurology, New York University Langone Medical Center, New York, NY, United States |
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We describe the evolution of chronic multiple sclerosis lesions from a quantitative MR imaging and spectroscopy perspective. Metabolite concentrations were obtained along with measures of lesion T1-hypointensity and size. Moderately hypointense lesions were more metabolically active than severely hypointense lesions, driving an increase in the glial marker myo-inositol. Correlational analyses revealed that lesion size is a better predictor of axonal health than T1-hypointensity, with lesions larger than 1.5 cm3 exhibiting terminal axonal injury. A positive correlation between changes in choline and in lesion size in moderately hypointense lesions implied that changes in lesion size are mediated by chronic inflammation. |
| 4067 | Computer #40 |
2D Localised Correlated Spectroscopy (L-COSY): A potential tool for identifying biochemical changes in Multiple Sclerosis |
1Imaging, HMRI, Newcastle, Australia, 2Imaging, TRI Brisbane, Brisbane, Australia, 3Neurology, John Hunter Hospital, Newcastle, Australia, 4Faculty of Health and Medicine, University of Newcastle, Newcastle, Australia |
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1H Magnetic Resonance Spectroscopic techniques (1H-MRS) have been utilised to assess inflammatory nature of both acute and chronic lesions as well as normal appearing brain tissue to understand the neuro degenerative irreversible component of multiple sclerosis (MS) from early stages1-3. However, due to high spectral overlap in one-dimensional (1D) 1H-MRS, it has been challenging to establish a standard specific spectral pattern in plaques or normal appearing brain tissues. L-COSY might provide the needed spectral dispersion |
| 4068 | Computer #41 |
Multiple Sclerosis: Assessment of normal-appearing white matter hypoperfusion with DCE MRI |
1Josef-Lissner-Laboratory for Biomedical Imaging, Institute for Clinical Radiology, Ludwig-Maximilians-University Munich, Munich, Germany, 2Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, United Kingdom, 3Institute for Clinical Radiology, Ludwig-Maximilians-University Munich, Munich, Germany, 4Institute for Clinical Neuroimmunology, Ludwig-Maximilians-University Munich, Munich, Germany |
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Several studies have reported diffuse hypoperfusion in normal-appearing white matter(NAWM) in patients with relapsing-remitting multiple sclerosis(RR-MS). Here, we investigate this issue using dynamic contrast-enhanced (DCE)MRI. The statistical power of a DCE-MRI acquisition to reveal hypoperfusion was estimated for n=16 patients at 96% using a Monte-Carlo simulation. 24 patients with RR-MS and 16 healthy controls underwent a DCE-MRI examination and cerebral blood flow (CBF), cerebral blood volume (CBV) and permeability-surface area product (PS) were quantified in NAWM, revealing no significant differences between groups. This indicates that, in our patient cohort, NAWM hypoperfusion is much less pronounced than in previous DSC studies. |
| 4069 | Computer #42 |
Structural connectivity in multiple sclerosis and simulation of disconnection |
1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 3Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy |
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Aim of the study was to quantify structural connectivity integrity in multiple sclerosis (MS) patients with different clinical phenotypes, to simulate a disconnection due to T2 visible lesions and to test its effect on network based measures. Diffusion tensor MRI was obtained from 239 MS patients and 131 healthy controls; connectivity matrices were produced and then artificially disconnected based on T2 visible lesion distribution. Global and nodal network metrics were calculated for both cases. Crucial nodes of the network were found to be different in strength between MS phenotypes. Disconnection simulation highlighted the role of T2 lesions in determining structural connectivity abnormalities. |
| 4070 | Computer #43 |
Preliminary Experience Using Magnetic Resonance Fingerprinting in Multiple Sclerosis |
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Biomedical Engineering, Cleveland Clinic, Cleveland, OH, United States, 3Radiology, Case Western Reserve University, Cleveland, OH, United States, 4Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, United States, 5Biogen, Boston, MA, United States, 6Mellen Center for Multiple Sclerosis Research and Treatment, Cleveland Clinic, Cleveland, OH, United States, 7Radiology, University Hospitals, Cleveland, OH, United States |
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Magnetic Resonance Fingerprinting (MRF) is used to simultaneously map T1, T2, and spin density in the normal appearing white matter and normal appearing grey matter of multiple sclerosis patients and healthy controls. Relaxation parameters measured by MRF are found to be significantly different between MS subjects and healthy controls, to distinguish between relapsing remitting MS and secondary progressive MS in certain brain structures, and to correlate with clinical measures of function and disability. |
| 4071 | Computer #44 |
QSM is sensitive to myelin changes just beyond the boundaries of conventional T2 lesion detection |
1Department of Radiology, Weill Cornell Medicine, New York, NY, United States, 2Department of Neurology, Weill Cornell Medicine, New York, NY, United States |
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MRI-derived measures of lesion accrual and tissue loss have acquired a central role in the understanding of MS disease evolution, pathogenesis of symptoms, and prediction of clinical outcome. Conventional MRI imaging is highly sensitive for detection of MS lesions, which are characteristically hyperintense on a T2 weighted images, however this technique lacks pathological specificity. QSM can help identify myelin and iron content changes during an MS lesion’s lifetime. |
| 4072 | Computer #45 |
Influence of cognitive impairment and depression on cortical thinning in patients with multiple sclerosis |
1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Department of Neuroradiology, Neurocenter of Southern Switzerland, Lugano, Switzerland, 3Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 4Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy |
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In this study, we investigated cortical thickness abnormalities associated with cognitive impairment and depression in 126 patients with multiple sclerosis (MS). Compared with controls, MS patients exhibited a widespread bilateral cortical thinning involving all brain lobes. While cognitive impairment was associated with atrophy of regions located in the fronto-parietal lobes (including the middle and superior frontal gyrus, the inferior parietal lobule and the precuneus), depression was linked to atrophy of the orbitofrontal cortex. This study shows that cortical thickness analysis was able to detect specific effects of clinical symptoms on cortical atrophy in MS. |
| 4073 | Computer #46 |
CE-MRV with concordant 4D flow MRI and ultrasound reveals no internal jugular venous outflow obstruction in multiple sclerosis |
1Centre for Advanced MRI, University of Auckland, Auckland, New Zealand, 2Radiology, University of Wisconsin - Madison, Madison, WI, United States, 3Medical Physics, University of Wisconsin - Madison, Madison, WI, United States |
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Contrast-enhanced MR venography scoring in internal jugular veins is performed and compared with 4D flow MRI and ultrasound assessment in patients with multiple sclerosis, patients with other neurological disorders and healthy controls. Narrowing assessment is shown to be more variable in flow MRI and ultrasound. |
| 4074 | Computer #47 |
Multimodal Characterization of Grey Matter Alterations in Neuromyelitis Optica |
1Xuanwu Hospital,Capital Medical University, Beijing, China, People's Republic of, 2Beijing, China, People's Republic of, 3Amsterdam, Netherlands, 4Hanzhou, China, People's Republic of |
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Combining double-inversion-recovery (DIR), high-resolution structural MRI, diffusion tensor imaging (DTI) and resting-state functional MRI (rs-fMRI), this study systematically investigated structural and functional alterations in grey-matter (GM) structures in thirty-five neuromyelitis optica (NMO) patients compared with healthy controls. We demonstrated that NMO exhibits both structural and functional alterations of GM in the cerebrum and cerebellum. Multimodal MRI techniques complementary worked to capture NMO-related GM abnormalities. GM alterations, especially diffusion abnormalities, correlated with cognitive impairment in NMO. These findings have important implications for understanding the roles of GM damage and also for highlighting multimodal MRI techniques as objective biomarkers in NMO. |
| 4075 | Computer #48 |
A longitudinal assessment of brain iron using quantitative susceptibility mapping (QSM) in multiple sclerosis (MS) over 2 years |
1Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States, 2MRI Molecular and Translational Research Center, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States, 3MR Research Laboratory, IRCCS Don Gnocchi Foundation ONLUS, Milan, Italy, 4Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany, 5Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States, 6Michael Stifel Center for Data-driven and Simulation Science Jena, Friedrich Schiller University Jena, Jena, Germany |
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Quantitative susceptibility mapping (QSM) is the most sensitive technique currently available to study brain iron in vivo. The technique opens the door to a longitudinal assessment of brain iron, bearing the potential to understand and disentangle factors resulting in the large scatter of reported iron concentrations in later decades of life. In the present work, we investigated longitudinal changes of brain magnetic susceptibility in a cohort of 40 healthy controls (HCs) and 160 multiple sclerosis (MS) patients over a period of 2 years. |
| Exhibition Hall | Wednesday, May 11, 2016: 16:00 - 17:00 |
| 4076 | Computer #49 |
LONG TERM EFFECTS OF SINGLE VS. REPEATED LOW INTENSITY PULSED FOCUSED ULTRASOUND TREATMENT WITH MICROBUBBLES |
1Frank Laboratory, Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD, United States, 2Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD, United States, 3National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, United States |
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One potential issue for using MR-guided pulsed Focused Ultrasound (pFUS) to open the blood brain barrier (BBB) is the lack of data on the long term effects. Safety determination in the brain have been limited to the MR characterization after repeated BBB opening that can be achieved without hemorrhage, edema and behavioral changes in non-human primates (Arvanitis, et al. 2015; Downs, et al. 2015). We use multimodal imaging technics to characterize long term effects of pFUS + MB in the rat brain. |
| 4077 | Computer #50 |
MRI of Peripheral Nerve: MT of Short T2 Components, Susceptibility and Diffusion Weighting of Collagen Components |
1University of California, San Diego, San Diego, CA, United States, 2Global MR Applications & Workflow, General Electric, San Diego, CA, United States, 3Clinical Neurosciences Center, University of Utah, Salt Lake City, UT, United States |
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The objective of this paper is to describe the use of several new approaches for magnetic resonance (MR) imaging of peripheral nerves. MR examinations were performed on fresh human median, tibial and sciatic nerve samples, as well as cadaveric forearms at 3T and/or 11.7T as well as one fresh human median nerve sample. Application of MR techniques used elsewhere in the body, and the use of MR microscopy show a variety of new imaging findings in peripheral nerve. This approach is likely to improve understanding of the MR appearances of peripheral nerve and lead to improved experimental and clinical studies. |
| 4078
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Computer #51 |
Convex Optimized Diffusion Encoding (CODE) for Improved SNR in Diffusion-Weighted Neuro MRI |
1Radiological Sciences, UCLA, Los Angeles, CA, United States, 2Biomedical Physics IDP, UCLA, Los Angeles, CA, United States |
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Spin Echo EPI Diffusion Weighted MRI (SE-EPI DWI) is widely used for neuro applications because of its speed. Conventional SE-EPI DWI approaches, however, often require long echo times (TE) which degrade SNR. Because SNR is inherently limited in high b-value DWI, TE must be kept as short as possible to ensure high-quality DWI. A Convex Optimized Diffusion Encoding (CODE) framework was developed to design waveforms which eliminate sequence dead times and minimize TE. CODE gradients were designed and implemented on a 3.0T scanner and demonstrated improved SNR in neuro DWI for healthy volunteers. |
| 4079 | Computer #52 |
Role of MR cerebrospinal fluid flow study in assessment of Ventriculomegaly in the Elderly |
1Radiology, Alexandria University Hospitals, Alexandria, Egypt |
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Elderly patients often present with ventriculomegaly, not only with normal aging, but also due to a multitude of neurological disorders. The aim of this work was to study the role of MR CSF flow studies in assessment of elderly patients with ventriculomegaly. We identified variable underlying causes of ventriculomegaly in 20 elderly subjects including communicating hydrocephalus, obstructive hydrocephalus, and age-related cerebral atrophy. |
| 4080 | Computer #53 |
Morphometric analysis of cerebrospinal fluid alterations by MRI for spontaneous intracranial hypotension patients before and after treatments |
1Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan, 2Radiology, Taichung Veterans General Hospital, Taichung, Taiwan, 3Neurological Institute, Taichung Veterans General Hospital, Taichung, Taiwan, 4College of Medicine, China Medical University, Taichung, Taiwan |
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Cerebrospinal fluid (CSF) is the fluid circulating through the subarachnoid space and providing a neuroprotective function as a hydraulic cushion for the brain and the spinal cord. CSF not only plays a vital role for normal brain function, but also servers numerous important functions in the central nervous system. However, CSF leaks are a key cause of new-onset headaches. Despite numerous reports characterizing CSF and its circulation in subarachnoid space, our understanding of CSF leakage remains limited. In this study, we calculate the CSF volumes in the brain and the spine of SIH patients using T2-weighted MRI images. |
| 4081 | Computer #54 |
Magnetic resonance spectroscopy reveals oral lactobacillus promotion of increases in brain GABA, N-acetyl aspartate and glutamate |
1Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada, 3Department of Nerurosurgery and Pediatric Neurosurgery, Medical University of Lublin, Lublin, Poland |
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We previously have demonstrated that administration of Lactobacillus rhamnosus (JB-1) to healthy male BALB/c mice, promotes consistent changes in GABA-A and -B receptor subtypes in specific brain regions, accompanied by reductions in anxiety and depression-related behaviours. In the present study, using magnetic resonance spectroscopy (MRS), we quantitatively assessed two clinically validated biomarkers of brain activity and function, glutamate + glutamine (Glx) and total N-acetyl aspartate + N-acetylaspartylglutamic acid (tNAA), as well as GABA, the chief brain inhibitory neurotransmitter. |
| 4082 | Computer #55 |
Analysis of brain volume in a 19 year-old extremely-preterm born cohort |
1Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 2Institute for Women's Health, University College London, London, United Kingdom, 3University College Hospital, London, United Kingdom |
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This abstract presents an analysis of brain tissue volume in a cohort of 69 extremely preterm born young adults and 50 term-born controls at 19 years of age. |
| 4083 | Computer #56 |
MEMRI Detection of Neuronal Activity Following Acute and Chronic Nicotine Exposure in Rats |
1Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Omaha, NE, United States, 2Second Affiliated Hospital, Dalian Medical University, Dalian, China, People's Republic of, 3Department of Radiology, University of Nebraska Medical Center, Omaha, Omaha, NE, United States |
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Rats with acute and chronic nicotine exposure were studied using manganese-enhanced MRI (MEMRI). Neuronal activity was found on nucleus accumbens and hippocampus in rats with acute nicotine exposure, and on nucleus accumbens and hippocampus, prefrontal and insular cortex. The neuronal activity was confirmed by immunohistology. The above-mentioned brain regions are believed to play roles in drug addiction. We demonstrate that MEMRI can be used to assess neuroadaptations from nicotine addiction. |
| 4084 | Computer #57 |
Mapping of Time and Space Spatial Preferences in the Hippocampus |
1sagol school of neuroscience, tel aviv university, tel aviv, Israel, 2tel aviv university, tel aviv, Israel |
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The hippocampus plays an important role in spatial and non-spatial episodic memory. Using DTI, a micro-structural probe sensitive to rapid neuroplasticity, and the Morris water maze, we investigated spatial preference for place and time in the hippocampus as revealed by changes in diffusion indices induced by learning of a specific location in the maze and the overall training experience. We were able to find a system-level mapping of space and time in the rat hippocampus. |
| 4085 | Computer #58 |
Cortical folding patterns in extremely preterm born young adults |
1Translational Imaging Group, Centre for Medical Image Computing, University College London, London, United Kingdom, 2University College London, London, United Kingdom, 3University College Hospital, London, United Kingdom, 4Institute for Women's Health, University College London, London, United Kingdom |
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Preterm born individuals may be subject to abnormal gyrification, associated with behavioural-cognitive deficit. In this work we perform a cortical folding analysis of the white-grey matter boundary in extremely preterm born young adults when compared to their term born peers, through a groupwise analysis using joint spectral matching. The results show that there are significant differences in folding in the temporal lobe, results which could be connected with poor executive function and language deficits in the extremely preterm cohort. |
| 4086 | Computer #59 |
Evaluation of Whole-Body Iron Loading in Transfusion-Dependent Patients with Quantitative Susceptibility Imaging |
1Tianjin First Central Hospital, Tianjin, China, People's Republic of, 2MR Collaboration NE Asia, Siemens Healthcare, Beijing, China, People's Republic of |
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To quantify the iron loading in the whole body among transfusion-dependent patients, 32 transfusion-dependent patients and 32 healthy volunteers were recruited to participate in this study. The quantitative susceptibility mapping was processed to get the susceptibility of the ROIs in the brain, and T2*values of their livers, pancreas and myocardium. Significantly higher iron levels in the putamen were found in transfusion-dependent patients (right/left=0.147±0.066/0.149±0.811ppm) compared with healthy controls(right/left=0.064±0.037/0.060±0.326ppm) (P=0.021/0.011). A ROC curve was performed, and the results suggested that liver T2* and pancreas T2* values can be great predictors to diagnose the iron overload in the brain ( AUC=0.877, 0.974, P＜0.01). |
| 4087 | Computer #60 |
Reproducibility of Cerebral Blood Flow Measurements Across MR Systems: A Matter of Magnet Geometry |
1Diagnostic Imaging, St Jude Children's Research Hospital, Memphis, TN, United States |
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For longitudinal investigations reproducibility and accuracy of ASL measurements are of essence. The purpose of this study is to investigate how magnet design and labeling position within the magnet impact CBF quantification. Our results indicate that CBF values are not always reproducible in our ultra-short wide bore scanner. Great variability may be introduced by the actual position of the labeling slice with respect to the magnet isocenter. The exact cause of this difference requires further investigation. However, positioning the labeling slice in isocenter provided a simple solution to overcome this issue and to measure reproducible CBF values. |
| 4088 | Computer #61 |
Quantitative pH using chemical exchange saturation transfer and phosphorous spectroscopy |
1Biomedical engineering, University of Alberta, Edmonton, AB, Canada, 2Medical Imaging, 2nd Affiliated Hospital of Shantou University Medical College, Shantou, China, People's Republic of, 3Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, MGH and Harvard Medical School, Charlestown, MA, United States, 4Math and Information Technology, Hanshan Normal University, Chaozhou, China, People's Republic of, 5Provincial key laboratory of medical molecular imaging, Shantou, China, People's Republic of |
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pH is a very important biochemical property that changes in many pathological states. Monitoring pH is of significance in early diagnosis and treatment therapy. However, there is lack of non-invasive methods to image pH in vivo effectively. Our study quantified the pH value using a chemical exchange saturation transfer (CEST) method in rat brain and established a strong correlation of pH between CEST and 31P-MRS in vivo, Pearson correlation factor is 0.819, P < 0.01. Because CEST imaging has superior spatial resolution to 31P-MRS, CEST may provide an alternative, straightforward, and effective way to obtain quantitative pH images in vivo. |
| 4089 | Computer #62 |
Double-tuned (1H/23Na) vs. clinically used 1H coil – Intraindividual comparison of image quality |
1Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Mannheim, Germany |
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Although 23Na-MRI can offer additional information regarding tissue function and viability compared to 1H-MRI several obstacles have impeded its clinical implementation, including hardware costs and technical challenges. One step towards a more widespread clinical use of 23Na-MRI would be the use of double-tuned (1H/23Na) coils. This would require morphologic and functional images with diagnostic image quality. The purpose of this study was therefore to prospectively compare image quality of a double-tuned (1H/23Na) vs. a clinically used 1H head coil in healthy subjects. Image data of both coils showed excellent image quality with no significant differences in SNR. |
| 4090 | Computer #63 |
Diffusion-weighted MR Imaging and Spectroscopy reveal brain tissue alterations induced by ionizing radiation in the mouse brain |
1UNIRS, NeuroSpin, I2BM, Life Sciences Division, Commissariat à l’Energie Atomique, Gif-sur-Yvette, France, 2Laboratoire de Radiopathologie, SCSR, iRCM, UMR 967, Life Sciences Division, Commissariat à l’Energie Atomique, Fontenay-aux-Roses, France |
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Patients frequently suffer from cognitive impairments following brain radiotherapy. Ionizing radiations are known to induce various brain alterations and impair neurogenesis. Following whole cerebral irradiation (3X5 Gy), we found significant changes in non-Gaussian water diffusion parameters (ADC0 and kurtosis) and related S-index, a new diffusion biomarker sensitive to changes in tissue microstructure, in the subventricular zone, a site of adult neurogenesis and in the olfactory bulbs. MRS exhibited a longitudinal decrease in taurine specifically in the olfactory bulbs. These results suggest that diffusion MRI and MRS could be used to monitor changes induced by radiation injury. |
| 4091 | Computer #64 |
Magnetic Resonance Imaging de-noising using the squared eigenfunctions of the Schrödinger operator: Application to brain MRI data. |
1Computer, Electrical and Mathematical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia, 2Department of Radiology, University Hospital of Gent, gent, Belgium, 3University of Gent, Gent, Belgium |
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A magnetic resonance imaging denoising method based upon the spectral analysis of the shrodinger operator is proposed.The method called semi-classical signal analysis SCSA, employs an adaptive filter to represent the MRI image as a set of useful vectors and others representing noise. The separation between signal and noise vectors is achieved using a soft and efficient threshold. Method validation is achieved on anatomical brain images acquired with low signal to noise ratio. The obtained results demonstrate that the SCSA is efficient in reducing noise while preserving image details necessary for accurate image diagnosis. |
| 4092 | Computer #65 |
Susceptibility Weighted Imaging in the Early Stages of Hypoxia |
1University Hospitals Coventry and Warwickshire, Coventry, United Kingdom, 2Warwick Medical School, Warwick University, Coventry, United Kingdom |
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The apparent changes in venous calibre on susceptibility weighted imaging (SWI) of six normal volunteers pre-hypoxia, during the first 12 minutes of hypoxia, and at 30 and 60 minutes were investigated. For all subjects there was a step increase in apparent venous calibre on SWI which occurred within the first few minutes of hypoxia, and this was maintained up to 60 minutes. The apparent increase in venous calibre occurred too rapidly after hypoxia induction to be entirely due to an increase in vessel volume. The vessels appear dilated because of the greater magnetic susceptibility of deoxyhaemoglobin than oxyhaemoglobin. |
| 4093 | Computer #66 |
Imaging of Nicotinamide adenine dinucleotide (NAD+) in vitro using CEST |
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Research Branch, Sidra Medical and Research Center, Doha, Qatar |
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Nicotinamide adenice dinucleuotide (NAD+) is a ubiquitous molecule present in all cells and tissues of the body with an important role in the redox reactions and metabolism. Small changes in NAD levels may lead to oxidative stress and may be a cause for various disorders. Currently, NAD can be detected in vivo only by 31P NMR spectroscopy. Chemical Exchange Saturation Transfer (CEST) MRI is an imaging technique which exploits the properties of exchangeable protons on the molecule for imaging. In the present study, we have shown the in vitro CEST effect of solution containing NAD+. |
| 4094 | Computer #67 |
Frontal-parieto-temporal white matter integrity in chronic HIV infection reflects a complex combination of education level, immune recovery, antiretroviral brain penetration and current neurocognitive functioning |
1UNSW Australia, NeuRA, Sydney, Australia, 2UNSW Australia, Sydney, Australia, 3NeuRA, Sydney, Australia, 4Reed College, Portland, WA, United States, 5St. Vincent's Hospital, Sydney, Australia, 6UCSF, San Francisco, CA, United States, 7The University of New South Wales, Randwick, Australia |
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DTI was performed in 40 HIV- men and 82 HIV+ men with comparable demographics and life styles. The study was designed to recruit chronic HIV+ participants with successful viral control. DTI was 32 directions; FA values were quantified in each participant in 12 skeleton regions of interest, which have been associated with HIV-related brain injury. The study present first evidence for complex brain repair processes in treated and chronic HIV infection arguing for careful multilevel characterization of HIV+ samples in neuroHIV DTI studies. The association of neurocognitive function with FA suggests ongoing vulnerability despite successful treatment. |
| 4095 | Computer #68 |
Evaluation of Cerebral Venous Oxygen Saturation in Patients with Long-Term Haemodialysis using Susceptibility Mapping |
1Department of Radiology, Tianjin First Central Hospital, Tianjin Medical University First Central Clinical college, Tianjin, China, People's Republic of, 2Department of Prophylactic Inoculation, Tianjin First Central Hospital, Tianjin Medical University First Central Clinical College, Tianjin, China, People's Republic of, 3Department of Radiology, Tianjin First Central Hospital, Tianjin Medical University First Central Clinical College, Tianjin, China, People's Republic of, 4Department of Haemodialysis, Tianjin First Central Hospital, Tianjin Medical University First Central Clinical college, Tianjin, China, People's Republic of, 5MR Collaboration NE Asia, Siemens Healthcare, Beijing, China, People's Republic of, 6Department of Radiology, Wayne State University, Detroit, MI, United States |
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The aim of this study was to explore cerebral venous oxygen saturation changes in long-term hemodialysis (HD) patients using susceptibility mapping (SWIM). SWIM was reconstructed from phase data of SWI and used to measure the susceptibility of cerebral veins in HD patients and healthy controls respectively. The results suggested that SWIM was a feasible and reliable method to measure the venous oxygen saturation. It can show the decrease of CMRO2 in HD patients and the susceptibility value of the left cerebral cortical vein is positively correlated with MMSE scores. |
| 4096 | Computer #69 |
Reduced Creatine Concentrations in Severe Short-sleep Insomnia Disorder |
1NeuroSleep and Woolcock Institute of Medical Research, The University of Sydney, Sydney, Australia, 2The University of New South Wales, Randwick, Australia, 33 Department of Respiratory and Sleep Medicine, RPAH, Sydney, Australia, 4Sydney Nursing School, Sydney, Australia, 5Nuffield Department of Clinical Neurosciences and Sleep & Circadian Neuroscience Institute, The University of Oxford, Oxford, United Kingdom |
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We investigated 31 subjects with Insomnia Disorder grouped by hierarchical cluster analysis into long (N = 19) or short (N = 12) sleep duration insomnia and 16 healthy, good sleeping controls using an aymmetric PRESS MRS sequence at 3T in the left occipital cortex. A super metabolite variable constructed from creatine, Asp, Glu and Gln separated short sleeping insomnia from long sleeping and controls, positively correlated with total sleep duration and negatively with wake-time after sleep onset. Short sleep is associated with reduced creatine concentration. |
| 4097 | Computer #70 |
Decreased Cortical GABA in Youth with Tourette's Disorder |
1Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Weill Medical College of Cornell University, New York, NY, United States |
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γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system, may play a role in the pathophysiology of Tourette’s disorder (TD). We used 1H MRS to measure GABA in the anterior cingulate cortex (ACC) and striatum of adolescents with TD and healthy controls (HC). Adolescents with TD had lower GABA spectra in the ACC than HC, suggesting a role for dysregulated ACC neurotransmitter function. Within the TD group, ACC GABA was positively associated with tic severity, potentially related to attempts at regulating or suppressing tics. Findings provide evidence for dysfunction of the central GABAergic system in TD. |
| 4098 | Computer #71 |
Neurotoxic side effects of immunosuppressive in patients after liver transplantation: Preliminary results of a brain 31P-MRS study |
1Institute for Neuroradiology, Hannover Medical School, Hannover, Germany, 2Institute for Neurology, Hannover Medical School, Hannover, Germany |
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Patients treated with immunosuppressive calcineurin inhibitors (CNI) for at least 3 years after liver transplantation were studied by using non-localized whole brain 31P-MRS at 3T to evaluate possible chronic neurotoxic side effects of the CNI. Global concentrations of brain high-energy metabolites Adenosine-5'-triphosphate (ATP) and phosphocreatine (PCr) were estimated. The values of the patient with different doses of CNI were compared with those of age-matched healthy volunteers. In our preliminary results significant lower concentrations of ATP and PCr were found in patients treated both with standard and low doses of CNI, indicating possible neurotoxic side effects. |
| 4099 | Computer #72 |
Quantitative Susceptibility Mapping – Comparison of Silent and Conventional Acquisitions |
1GE Healthcare, Menlo Park, CA, United States, 2GE Global Research, Munich, Germany, 3GE Healthcare, Waukesha, WI, United States, 4GE Global Research, Niskayuna, NY, United States, 5GE Healthcare, San Diego, CA, United States |
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A silent 3D multi-echo gradient-echo pulse sequence is developed for quantitative susceptibility mapping (QSM). The new, silent sequence is compared to the standard acquisition and gives comparable susceptibility values. The silent acquisition gives the benefit of patient comfort and workflow ease at some cost to SNR and acquisition time. |
| Exhibition Hall | Wednesday, May 11, 2016: 16:00 - 17:00 |
| 4100
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Computer #73 |
Mapping of ex-vivo human cervical spinal cord using magnetic resonance micro-imaging |
1Centre for Advanced Imaging, University of Queensland, Brisbane, Australia, 2Najran University, Najran, Saudi Arabia, 3Faculty of Health Sciences, Curtin University of Technology, Perth, Australia, 4National University Hospital Systems, Kent Ridge, Singapore, 5School of Biomedical sciences, The University of Queensland, Brisbane, Australia |
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Imaging the spinal cord is normally performed at lower magnetic field with limited resolution. In this study, 13 ex-vivo cervical spinal cords have been scanned at 9.4T to provide high-resolution images. A variation of the position of the rostral brachial motorneurons among the cords was used to classify the samples into normal and pre-fixed types. For each segment, the length and GM/WM total areas were measured. A high resolution MRI template of the normal type samples was created to assist registration and delineation of spinal cord structures and improve the accuracy of diagnostic radiology. |
| 4101 | Computer #74 |
Increased Apparent Diffusion Coefficient And Thickness In The Optic Nerve Is Associated With Visual Acuity Loss In Optic Pathway Glioma |
1Developmental Imaging & Biophysics Section, University College London Institute of Child Health, London, United Kingdom, 2Great Ormond Street Children's Hospital, London, United Kingdom |
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Conventional MRI sequences have so far failed to provide imaging biomarkers that reliably differentiate asymptomatic optic pathway glioma (OPG) tumours from those which cause visual impairment. ADC maps are now acquired as standard in most institutions, and despite their typically limited resolution, may provide quantitative assessment of tumour invasion of the optic nerve. We measured ADC and optic nerve thickness using standard clinical imaging sequences in OPG patients, in conjunction with visual assessment. We found that the product of ADC and nerve thickness showed a significant correlation with visual acuity, and was significantly increased in patients who had gone blind. |
| 4102 | Computer #75 |
Interleaved acquisition of high resolution 3D susceptibility-weighted and FLAIR MRI |
1Department of Diagnostic and Interventional Imaging, The University of Texas Health Science Center at Houston (UTHealth), houston, TX, United States, 2Philips Healthcare, Cleveland, OH, United States |
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Combining the contrast of susceptibility weighted imaging (SWI) and fluid-attenuated inversion recovery (FLAIR) allows simultaneous visualization of multiple sclerosis lesions and the penetrating veins and iron deposition. However, the need for image registration, to account for patient motion between the scans, adds to the complexity of the post-processing pipeline, and introduces undesirable blurring of the image. We have developed an interleaved sequence for simultaneous acquisition of 3D FLAIR and SWI data, which produces self-registered images in a clinically feasible time, greatly simplifying the post-processing steps and eliminating interpolation effects. The interleaved time delays in between the FLAIR and SWI modules provide a degree of freedom for further optimization of the image contrast. Experiments in MS patients show the utility of the proposed sequence. |
| 4103 | Computer #76 |
Improved reproducibility in subcortical gray matter atrophy measurement using FIRST and FreeSurfer |
1Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, Netherlands, 2Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, Netherlands, 3Image Analysis Center, VU University Medical Center, Amsterdam, Netherlands |
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Interest in measuring brain atrophy in neurodegenerative diseases such as Multiple Sclerosis (MS) and Alzheimer’s disease (AD) is growing. To this end, FreeSurfer and FSL-FIRST are widely used as fully automated algorithms for quantification of the brain volume and volume change in both cross-sectional and longitudinal MRI studies. We have tested reproducibility of these methods in measuring deep gray matter atrophy rates in a group of subjects consisting of healthy aging, mild cognitive impairment and AD. We showed that using longitudinal mode for FreeSurfer and highest number of modes for FIRST provides the best reproducibility that is similar for FreeSurfer and FIRST. |
| 4104 | Computer #77 |
A SEMI-AUTOMATIC METHOD TO SEGMENT MULTIPLE SCLEROSIS LESIONS ON DUAL-ECHO MAGNETIC RESONANCE IMAGES |
1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 3MRI Center “SUN-FISM”, Second University of Naples and Institute of Diagnosis and Care “Hermitage-Capodimonte, Naples, Italy, 4I Division of Neurology, Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Second University of Naples, Naples, Italy, 5Department of Neurological and Behavioral Sciences, University of Siena, Siena, Italy, 6Department of Radiology and Nuclear Medicine, MS Centre Amsterdam, VU University Medical Centre, Amsterdam, Netherlands, 7NMR Research Unit, Queen Square MS Centre, UCL Institute of Neurology, London, United Kingdom, 8Department of Neurology, Medical University of Graz, Graz, Austria |
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Aim of the study was to develop a semi-automatic method for the segmentation of hyperintense multiple sclerosis (MS) lesions on dual-echo (DE) PD/T2-weighted scans. DE MRI scans were obtained from 6 different European centers from 52 MS patients with a mean lesion load of 10.3 (± 11.9) ml. The method was based on a region growing approach initialized by manual identification of lesions and a priori information. The segmentation results with the new method showed high accordance with the ground truth and a low misclassification of lesion voxels. Furthermore, operator time required for lesion segmentation was drastically reduced. |
| 4105 | Computer #78 |
Subcortical brainstem changes in the motor system in patients with chronic spinal cord injury revealed by quantitative MRI protocols |
1Spinal Cord Injury Center Balgrist, University of Zurich, Zurich, Switzerland, 2Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom, 3Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom, 4Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany |
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Neurodegeneration and neuroplasticity within the brainstem is poorly understood in patients suffering from spinal cord injury (SCI). We acquired quantitative MRI data of the brainstem using a multi-parameter mapping protocol to assess trauma-induced volumetric and microstructural changes after SCI. We show focal atrophic changes within different subregions of the brainstem in chronic SCI patients and their correlation with clinical outcomes. Neuroimaging biomarkers using quantitative MRI at the brainstem level could be applied to complement clinical assessments during rehabilitation and interventional studies. |
| 4106 | Computer #79 |
Comparison of CEST and [18F]-FDG Imaging in Patients with Brain Tumor: A hybrid PET/MR Study |
1Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, 2Philips Healthcare, Beijing, China, People's Republic of, 3Department of Radiololgy, Shengjing Hospital, Shenyang, China, People's Republic of, 4Philips Healthcare, Cleveland, OH, United States |
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Hybrid PET/MR provides a high resolution anatomical and metabolic imaging approach to evaluate human brain tumors. As a novel molecular MRI technique, CEST MRI has been successfully employed in clinical practice. The combination of [18F]-FDG and CEST images will provide further supplementary information on the study of clinic and molecular mechanism for human brain tumors. |
| 4107 | Computer #80 |
Fast and full coverage dual-venc 4D flow MRI: can time-averaged acquisition be useful? |
1Biomedical Engineering, Northwestern University, Chicago, IL, United States, 2Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States, 3Biomedical Engineering, Northwestern University Feinberg School of Medicine, Chicago, IL, United States |
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This work compares the utility of time-averaged vs. time-resolved dual-venc 4D flow MRI to look at intracranial blood flow distribution for applications such as evaluation of cerebral arteriovenous malformation (AVM). Time-averaged scans provide larger FOV, no additional time for image reconstruction after the scan and net flow distributions that correlate well with time-resolved scans. |
| 4108 | Computer #81 |
Intraoperative MRI Guided Resection for Glioblastoma Results in Increased Short-term Survival Compared to Conventional Surgery |
1Radiology, HCMC, Minneapolis, MN, United States, 2Radiology, University of Minnesota, Minneapolis, MN, United States, 3John Nasseff Neuroscience Institute, Allina Health, St. Paul, MN, United States, 4John Nasseff Neuroscience Institute, Allina Health, Minneapolis, MN, United States, 5MCC Biostatistics Core, University of Minnesota, Minneapolis, MN, United States |
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A retrospective analysis of survival after resection of glioblastoma was performed comparing use of intraoperative MRI with conventional surgery. There was a significant difference in extent of resection, with more gross total resections achieved with iMRI. There was a significant improvement in overall survival at 6 months with iMRI. The groups had equivalent survival from 12-36 months. Younger age was correlated with longer overall survival. |
| 4109 | Computer #82 |
Metabolic and morphological characterization of the triple transgene mouse model of Alzheimer disease: effects of palmitoylethanolamide on the onset and progression of the AD-pathology |
1Cell Biology and Neurosciences, Istituto Superiore di Sanita', Roma, Italy, 2Department of Physiology and Pharmacology “Vittorio Erspamer”., University of Rome SAPIENZA, Rome, Italy, 3Dipartimento di Medicina Clinica e Sperimentale, Università degli Studi di Foggia, Foggia, Italy |
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Alzheimer disease (AD) is characterized clinically by progressive cognitive decline, and pathologically by the presence in the brain of senile plaques composed primarily of amyloid-beta peptide and neurofibrillary tangles containing hyperphosphorylated tau protein. Here we investigated the effects ofa naturally occurring amide of ethanolamine and palmitic acid (PEA), abundant in the CNS to contrast the AD phenotype in triple transgene (PS1, APP and Tau) mice model, by in vivo 1H MRI and MRS and histology. Our data indicate that PEA treatment affects brain metabolism as a function of age and that PEA rescues altered molecular pathways that can mimic some traits of AD |
| 4110 | Computer #83 |
Network-wide longitudinal atrophic covariance after ischaemic stroke |
1Stroke Division, The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia, 2Epilepsy Division, The Florey Institute of Neuroscience and Mental Health, Heidelberg, Australia |
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Brain atrophy is common after stroke. The extent and pattern of atrophy has not been well investigated and has been limited to localised atrophy and cross-sectional studies, despite network-wide effects of stroke on brain structure and function. We examined correlations in the rate of longitudinal cortical thickness change in stroke patients, compared to healthy age-matched controls. We aimed to investigate whether patterns of neurodegeneration occur in healthy networks as in aging and dementia. We provide evidence of correlations in the rate of cortical atrophy within the DMN suggesting a process of network-based degeneration one year after stroke. |
| 4111 | Computer #84 |
Experimentally Optimizing Labeling Position in Pseudo-continuous ASL in the Presence of Carotid Artery Stenting |
1GE Healthcare, Taipei, Taiwan, 2GE Healthcare MR Research China, Beijing, China, People's Republic of, 3Department of Radiology, Taipei Medical University - Shuang Ho Hospital, New Taipei City, Taiwan |
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Pseudo-continuous arterial spin labeling (pCASL) has been recently used for investigating cerebral hemodynamic change on the patient receiving carotid artery stenting (CAS) because it permits repeated measurement of absolute cerebral blood flow in a short interval without MR contrast agent or radioactive material. However, labeling efficiency of pCASL has been proved to be dependent on B0 inhomogeneity. Labeling position may need to be carefully applied after CAS. The aim of this study was to experimentally determine the optimal labeling position for pCASL with minimal frequency shift caused by stent in exploring cerebral perfusion in the patient with CAS treatment. |
| 4112 | Computer #85 |
Assessment of Moyamoya Disease by Using Vessel Wall Imaging with MSDE Technique: Feasibility and Implication |
1Department of Radiology, The University of Tokyo, Tokyo, Japan, 2Department of Radiology, The University of Tokyo Hospital, Tokyo, Japan, 3Global MR Applications and Workflow, GE Healthcare, Tokyo, Japan |
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We assessed diagnostic feasibility of vessel wall imaging with MSDE-prepared, 3D T1-weighted variable refocusing flip angle fast spin echo MR imaging (CUBE T1) in differentiation between moyamoya disease (MMD) and intracranial atherosclerotic disease (ICAD), both of which can cause stenosis of the intracranial arteries. MSDE-prepared CUBE T1 enabled correct differentiation in our cohorts and may be helpful to differentiate MMD from ICAD when luminal narrowing is found on conventional brain MRA. |
| 4113 | Computer #86 |
The integrity and atherosclerosis of Circle of Willis detected by bright-blood and black-blood MRI are associated with severity of stroke |
1Center for BioMedical Imaging Research, Tsinghua University, Beijing, China, People's Republic of |
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Circle of Willis (CoW) is an important source of collateral blood flow, which may influence the severity of ischemia stroke. However, traditional methods only evaluate the luminal conditions of CoW. This study evaluate the luminal and vessel wall conditions of CoW using bright- and black-blood MRI. We found that most stroke patients have incomplete CoW, and patients with atherosclerotic CoW tends to have larger ischemic infraction. More importantly, the infarction size in stroke patients was significantly associated with integrity&atherosclerosis of CoW, suggesting that the integrity and atherosclerosis of CoW may be a risk factor for stroke severity. |
| 4114 | Computer #87 |
Characterization of Asymptomatic Intracranial Atherosclerosis using 3D High Resolution Contrast-enhanced MRI |
1The Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins Hospital, Baltimore, MD, United States, 2Shandong Medical Imaging Research Institute, Shandong University, Jinan, China, People's Republic of, 3Inner Mongolia Autonomous Region People's Hospital, Inner Mongolia, China, People's Republic of, 4Department of Neurology, The Johns Hopkins Hospital, Baltimore, MD, United States, 5F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States |
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Although most of strokes occur in asymptomatic patients, most studies have been conducted in symptomatic cohort. Here we aimed to characterize ICAD in stroke-free participants and compare with stroke patients using 3D high-resolution contrast-enhanced BBMRI. Nineteen asymptomatic and 15 stroke patients were included and underwent a standardized protocol which contains 3D TOF MRA and pre- and post-contrast 3D BBMRI imaging. Plaque enhancement was categorized, and morphology and signal-based measurements were compared. The results showed that asymptomatic plaques demonstrated lower contrast-enhancement compared with symptomatic plaques. Contrast-enhancement of ICAD may serve as a marker for plaque stability, providing insight into stroke risk. |
| 4115 | Computer #88 |
Contralateral Cerebro-Cerebellar White Matter Pathways for Verbal Working Memory: A Combined Diffusion Spectrum Imaging and fMRI Study |
1Psychology, Nanyang Technological University, Singapore, Singapore, 2Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan, 3The Queensland Brain Institute, The University of Queensland, Brisbane, Australia, 4The Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia, 5Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan, 6Department of Radiology, National Taiwan University College of Medicine, Taipei, Taiwan, 7Molecular Imaging Center, National Taiwan University, Taipei, Taiwan, 8Centre for Research And Development in Learning, Nanyang Technological University, Singapore, Singapore |
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Diffusion spectrum imaging was employed to establish structural connectivity between cerebro-cerebellar regions co-activated during verbal working memory. IFG, IPL, pons, thalamus, superior cerebellum and inferior cerebellum were used as seed points to reconstruct the white matter cerebro-cerebellar circuitry. The reconstructed pathways were examined further to establish the relationship between structural and effective connectivity as well as the relationship between structural connectivity and verbal working memory performance. It was found that structural connectivity is indirectly related to effective connectivity but does not predict it. Additionally, it was demonstrated that the integrity of the ponto-cerebellar tract is an important factor in explaining individual differences in verbal working memory. The findings of the study furthered our understanding of the relationship between structural and functional connectivity and provided insight to the variability in verbal working memory performance. |
| 4116 | Computer #89 |
Interpreting patterns of BOLD responses to carbon dioxide through flow resistance |
1Department of Physiology, University of Toronto, Toronto, ON, Canada, 2Departments of Anaesthesia, University Health Network, Toronto, ON, Canada, 3Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada, 4Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, ON, Canada, 5Department of Anaesthesia, University Health Network, Toronto, ON, Canada |
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The patterns of BOLD changes in response to a ramp CO2 stimulus ranging from hypocapnia to hypercapnia can be classified into four types, based on the two linear slopes fitted to each range. We describe the physiology underlying the different response patterns using a simple model of two vascular beds competing for the same limited blood supply; deriving the sigmoidal resistance changes in each branch of the model from measured BOLD responses. We illustrate the use of the model to analyse the BOLD responses in an example patient. |
| 4117 | Computer #90 |
Relationship between the position of the plaque signal intensity identified by 3D-FSE T1W MR plaque imaging and development of microembolic signals on transcranial Doppler during exposure procedure of carotid arteries in endarterectomy |
1Department of Neurosurgery, Iwate Medical University, Morioka, Japan, 2Department of Neurology and Gerontology, Iwate Medical University, Morioka, Japan, 3Institute for Biomedical Sciences, Iwate Medical University, Morioka, Japan |
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Preoperative 2D MR carotid plaque imaging can assess plaque vulnerability. It may allow improved risk stratification for patients considered for CEA and may be associated with development of MES during CEA. On the other hand, it is unclear what position of high signal intensity in the plaque, especially at the position showing maximum stenosis or maximum signal intensity, is deeply associated with MES, and it is difficult to validate it by the 2D plaque imaging. The aim of the present study was to determine where in the plaque is deeply associated with development of MES on TCD during CEA in carotid artery stenosis, using 3D-FSE T1W plaque imaging. |
| 4118 | Computer #91 |
A semi-automatic workflow of constructing printable 3D models for cerebrovascular surgical planning based on MR angiography and CT data |
1Huaxi MR Research Center, Department of Radiology., West China Hospital, Chengdu, China, People's Republic of, 2Department of Neurosurgery, West China Hospital, Chengdu, China, People's Republic of, 3Laboratory of Pathology, West China Hospital, Chengdu, China, People's Republic of |
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A semi-automatic workflow, which can be done within one hour and need minimal manual intervention, was proposed for constructing printable 3D models for cerebrovascular surgical planning based on MR angiography and CT data. The constructed models were consistent with the findings of MR angiography and have the potential to help surgeons to rehearse the operation beforehand and reduce operative risk. |
| 4119 | Computer #92 |
Z-shim with Parallel-Transmit Methods (pTX) in MR Neuro Applications |
1MR Application Development, Siemens Healthcare, Erlangen, Germany |
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In clinical 3T imaging, gradient-echo-based sequences often suffer from signal loss induced by patient-specific susceptibility artifacts. To tackle this problem, a proposed local signal recovery z-shim method using parallel transmission was implemented for a clinical setup. The approach was further extended by an automated slice-specific delay-time calculation to ensure user-friendly operation as well as maximal signal gain in artifact regions. Studies in humans were carried out using commonly used GRE and EPI sequences. Signals could be nearly fully recovered in artifact regions; tSNR gain maps for EPI time series showed an increase up to 148%. |
| 4120 | Computer #93 |
Noninvasive imaging of oxygen extraction fraction in adults with sickle cell anemia |
1Vanderbilt University Medical Center, Nashville, TN, United States, 2Johns Hopkins University, Baltimore, MD, United States |
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The goal of this work is to apply hemo-metabolic MRI to evaluate relationships between oxygen extraction fraction (OEF), cerebral blood flow (CBF), and clinical impairment in adults with sickle cell anemia (SCA). Healthy (n=11) and sickle cell anemia (n=34) participants received neurological evaluation, head/neck-angiography, structural-MRI, CBF-weighted-MRI, and T2-relaxation-under-spin-tagging (TRUST)-MRI. CBF and OEF were elevated (P<0.05) in SCA relative to control participants; OEF (P<0.0001) but not CBF was increased in SCA participants with higher clinical impairment. Data provide support for TRUST-MRI being able to quickly and noninvasively detect elevated OEF in SCA participants with high levels of clinical impairment. |
| 4121 | Computer #94 |
Clinical Evaluation of TOF-MRA with Sparse Undersampling and Iterative Reconstruction (Sparse TOF) for Cerebral Aneurysms. |
1Kyoto University Graduate School of Medicine, Kyoto, Japan, 2Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan, 3Siemens, Erlangen, Germany |
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Sparse TOF has demonstrated the potential to accelerate TOF MRA. We conducted comparison study targeting patients with cerebral aneurysms to check the clinical relevance of evaluation of aneurysms on Sparse TOF 3X, 5X and TOF with parallel imaging (PI TOF). MIP images of patients with cerebral aneurysms were blindly evaluated by one neuroradiologist, and the sum of grades were compared among Sprase TOF 3X, 5X and PI-TOF 3X. Sparse TOF 3X and 5X were reconstructed with clinically acceptable time, and cerebral aneurysms were visible in both Sparse TOF 3X and 5X with equivalent quality as PI TOF. |
| 4122 | Computer #95 |
A probabilistic atlas based on 168 subjects for labeling of brain arteries |
1Department of Radiation Sciences, Umeå University, Umeå, Sweden, 2Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden, 3Centre for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden, 4Department of Clinical Neuroscience, Umeå University, Umeå, Sweden |
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The cerebral arterial system is complex with large inter-individual spatial variations, which are potentially challenging for automatic methods. The objective of this work was to construct an artery specific probabilistic atlas of 16 large cerebral arteries, based on 168 subjects, and to investigate if the regional specificity of vascular branches was sufficient to permit atlas based arterial labeling. Voxels of the arterial centerlines was labeled according to the highest probability at the corresponding location in the atlas. The rate of correctly labeled voxels was over 80% for all arteries, which should be sufficient to permit atlas based arterial labeling. |
| 4123 | Computer #96 |
Magnetic Resonance imaging features of normal and abnormal fetal Ganglionic Eminence. A pictorial essay. |
1Radiology and Neuroradiology, Children's Hospital V. Buzzi, Milan, Italy, 2Radiology Institute, University of Milan, Milan, Italy |
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Ganglionic eminence (GE) is the main proliferative structure of the ventral telencephalon and contributes to GABA-ergic cortical interneuron population; GE imaging characterization in normal and abnormal conditions is poor. After searching a 3500 cases fetal MR database, we illustrate normal GE features, its abnormalities and its possible associations. GE malformations are divided: 1) bilateral symmetric cavitations as inverted C shape separating GE from parenchyma; 2) GE volume increase associated or not with the above mentioned cavitation. About half of cases are associated with micro-lissencephaly, the others with minor-moderate anomalies. As group apart are presented clastic GE lesions, featuring haemorrhagic changes. |
| Exhibition Hall | Wednesday, May 11, 2016: 17:00 - 18:00 |
| 4124 | Computer #1 |
Magnetic Resonance Imaging of hippocampal subfield in a large sample of posttraumatic stress disorder |
1Huaxi MR Research Center (HMRRC), radiology department, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 2radiology department, The First People's Hospital of Zunyi, Zunyi, China, People's Republic of |
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We analysis hippocampal subfields volume changes in a relatively large sample of adult patients with post-traumatic stress disorder and same stressor event survivors using an automatically segmentation protocol. Our findings provided evidence that the responsive change of hippocampus after stress which cause cellular edema or at a early stage of the disorder. The second find is the difference between genders referring to the role of hippocampus in PTSD etiology. Male patients seem to be more likely affected in right hippocampus while in female patients, left hippocampus seems contributed more. |
| 4125 | Computer #2 |
Redox Dysregulations in Schizophrenia Revealed by in vivo NAD+/NADH Measurement |
1McLean Imaging Center, McLean Hospital, Harvard Medical School, Belmont, MA, United States, 2Psychotic Disorders Division, McLean Hospital, Harvard Medical School, Belmont, MA, United States, 3Program for Neuropsychiatric Research, McLean Hospital, Harvard Medical School, Belmont, MA, United States, 4Behavioral Psychopharmacology Research Laboratory, McLean Hospital, Harvard Medical School, Belmont, MA, United States |
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In this work, we demonstrated the feasibility of 31P MRS-based in vivo intracellular redox state quantification at 4 T. We applied this novel method to investigate oxidative stress in the frontal lobe of chronic and first-episode SZ as well as first-episode BD patients. We found evidence for striking Rx reductions in SZ, with every chronic SZ patient showing an Rx of at least one standard deviation below the control mean. Rx reduction was of even greater magnitude among first-episode SZ patients. This study illustrates the power of examining in vivo brain redox dysregulation (measured as Rx) in psychiatric disorders. |
| 4126 | Computer #3 |
Functional Disconnectivity in Schizophrenia Patients with Auditory Hallucinations: a Dynamic Resting-State Functional MRI Study with a Multiband EPI Sequence |
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 2Department of Psychiatry, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 3Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, United States |
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A simultaneous multi-slice multiband EPI sequence, which could significantly increase temporal resolution for the fMRI scanning, was adopted to investigate the dynamic functional connectivity in the schizophrenia patients with auditory hallucinations. We found that, relative to traditional static functional connectivity calculation, dynamic analysis evaluated with multiband EPI provides much more information, including more widespread aberrant functional connectivity maps across different states and their temporal variability over time. The expanded information may help to give better insight into the pathological processes and subsequently reveal the spontaneous model of affected networks in schizophrenia. |
| 4127 | Computer #4 |
Glutamatergic metabolism and disease severity in Schizophrenia: a 7T MRS study |
1The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, United States, 3Radiology, Kennedy Krieger Institute, Baltimore, MD, United States |
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Imbalance in the glutamatergic system is implicated in the pathophysiology of schizophrenia. Various previous MRS studies have reported altered levels of glutamate and/or glutamine in schizophrenia, however most of these studies have been performed at 3T or lower where separation from Glu from Gln is challenging, and few have looked at correlations with disease severity or cognitive impairment. The purpose of this study was to investigate neurochemical differences in participants with and without schizophrenia using high-resolution 7T MRS in multiple brain regions, and to exam correlations with measures of cognitive impairment, function and symptom severity. |
| 4128 | Computer #5 |
Microstructural alterations detected by dMRI in KO mouse model showing schizophrenic like phenotype |
1CIBM-AIT, École Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland, 2Laboratory of Behavioral Genetics, École Polytechnique Fédérale de Lausanne, EPFL, Lausanne, Switzerland, 3Department of Radiology, University of Geneva and Lausanne, Geneva, Lausanne, Switzerland |
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Schizophrenia is a severe mental disorder that afflicts 1% of the world’s population. However, the cause of this disorder remains unknown. Increasing evidence points toward a neurodevelopmental mechanism, which implicates genes involved in neuronal proliferation, migration, or synapse formation. We investigate microstructural changes by ex-vivo diffusion MRI in PSA-KO mice brain. Trends of microstructural alterations were visible in a few fiber tracts such as ST, ST-post, AC and FX. These preliminary results suggest that altered plasticity during development of the PSA-KO mice, presenting schizophrenic like phenotype and altered sociability, creates long term effects and structural alterations depicted by dMRI. |
| 4129 | Computer #6 |
Prediction of treatment response with multi-modality MRI in first-episode antipsychotic-naive schizophrenia |
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 2Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan university, Chengdu, China, People's Republic of |
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Using SVM to characterize structural and functional pattern implicated in antipsychotic-naive schizophrenia to predict the response of anti-psychotic treatment and also to examine the structural neuroanatomy and functional activity . And revealed that anatomical and functional changes revealed by Multi-modality MRI in first-episode schizophrenia patients before treatment showed the potential in predicting the one year treatment response, which could help psychiatrists to make treatment strategy for individual patient in future. |
| 4130 | Computer #7 |
31P MRS study of schizophrenia induced changes of energy metabolism in activated cerebral cortex. |
1Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, Moscow, Russian Federation, 2Radiology, Scientific Research Institute of Children's Emergent Surgery and Trauma, Moscow, Russian Federation, 3Scientific Centre of Mental Health, Moscow, Russian Federation, 4Semenov Institute of Chemical Physics of Russian Academy of Sciences, Moscow, Russian Federation |
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31P MRS in the period of neuroactivation allows direct analysis of metabolic response on energy consuming processes. In this study we revealed decreased creatine kinase system response in visual cortex of early stage schizophrenia patients in the period of videostimulation: while PCr in normal activated cortex is reduced for ATP regeneration during activation, no PCr decrease was observed in patients. The data obtained allowed to offer a new neuronal metabolism scheme in response to stimulation at early stage of schizophrenia. |
| 4131 | Computer #8 |
A novel framework for global comparison of tract-topology between subjects reveals callosum shape variations in first episode psychosis |
1CUBRIC, School of Psychology, Cardiff University, Cardiff, United Kingdom, 2School of Medicine, Newcastle University, Newcastle, United Kingdom, 3Neuroscience and Mental Health Research Institute (NMHRI), School of Medicine, Cardiff University, Cardiff, United Kingdom |
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Changes in the size and shape of white matter tracts are known to be associated with the onset or progress of various brain disorders. Common techniques for characterising tract shape include measuring cross sectional area or thickness1-3, Fourier descriptors4 and measures of streamline dispersion5. Here we present a novel principal component analysis (PCA)-based method and demonstrate two ways in which those representations may be used to examine inter-group differences in tract shape. As an example, we compare 30 first-episode psychosis patients with age/sex matched controls and find significant shape differences in the genu of the callosum. |
| 4132 | Computer #9 |
Common Pattern of Gray Matter Changes in First Episode Schizophrenia Patients with and without Antipsychotics: VBM Meta-analyses Using Signed Differential Mapping |
1Radiology, Sichuan University, Chengdu, China, People's Republic of, 2Chengdu, China, People's Republic of |
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Current study provides an insight about the brain morphological changes of first episode schizophrenia patients at drug-naive state and after antipsychotic treatment. Our study reveals that GM changes in frontal, temporal and insular regions are the fundamental regions of pathologic GM changes in first-episode schizophrenia irrespective of antipsychotic medication. This common pattern of GM changes in first episode schizophrenia patients with and without antipsychotics suggest the anatomical deficits involved in the fronto-temporal and limbic regions are likely to be the trait- instead of state-related changes at the early course of illness in schizophrenia. Until now only assumptions have been made about the potential effects of antipsychotics rather than making a strong statement due to lack of proper investigation methods and also due to difficulty in gaining access to a satisfactory number of drug naïve and medicated patients group of the same age. We therefore hope this study would be helpful in providing important information about the pathology of the schizophrenic brain after the early course of treatment with antipsychotics. |
| 4133 | Computer #10 |
Reduced gamma-amino butyric acid and elevated Glu/Gln complex in the anterior cingulate cortex of medicated schizophrenic patients |
1Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong, 2Philips Healthcare, Hong Kong, Hong Kong, Hong Kong, 3Institute of Mental Health, Castle Peak Hospital, Hong Kong, Hong Kong, 4Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia, 5Neuropsychology and Applied Cognitive Neuroscience Laboratory, Chinese Academy of Sciences, Beijing, China, People's Republic of, 6Psychiatry, The University of Hong Kong, Hong Kong, Hong Kong, 7Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD, United States |
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Gamma-amino butyric acid (GABA) is thought to play an important role in the pathophysiology of schizophrenia. The anterior cingulate cortex (ACC) has been reported to exhibit functional and morphological abnormalities in schizophrenic patients compared to healthy controls(HC). In this pilot study, absolute concentrations of GABA([GABA]abs) and Glx([Glx]abs) were measured in the ACC of 9 schizophrenic patients and 14 HC at 3.0T. Significant lower [GABA]abs level in ACC of schizophrenic patients might provide evidence of abnormalities in GABAergic neurotransmission in schizophrenia. Significant positive correlation between [Glx]abs and positive symptoms subscale might indicate Glx level is specific for positive symptoms in ACC. |
| 4134 | Computer #11 |
A 7T MRS Study of First Episode Psychosis: glutamatergic abnormalities and correlations with symptom severity |
1The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Radiology, Kennedy Krieger Institute, Baltimore, MD, United States |
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Imbalance in glutamatergic systems is implicated in the pathophysiology of psychosis. The purpose of this study was to assess differences in metabolite levels between subjects with a first episode of psychosis (FEP) and healthy controls, and to study correlations between metabolites and measures of disease severity, including neuropsychological scales, positive and negative symptoms. |
| 4135 | Computer #12 |
Glutamatergic metabolite concentrations in the superior temporal gyrus in schizophrenia are increased and glutamate predicts neuroticism |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany, 2Charité Universitätsmedizin Berlin, Berlin, Germany, 3Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany |
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Findings of deviant glutamate (Glu) and glutamine (Gln) levels in brain of patients support the glutamate hypothesis of schizophrenia. Thickness and volume of the left superior temporal gyrus (STG) are established endophenotypes of schizophrenia. We quantified glutamatergic metabolites using proton MRS with SPECIAL in the left STG of schizophrenic patients and controls, and investigated the relationships between Glu and personality traits. Glu was significantly higher in patients than in controls, Gln likewise but with a weak trend only. Glu predicted neuroticism in patients. Our results suggest dysfunctional glutamatergic neurotransmission in STG and confirm widespread Glu increases in cortical regions in schizophrenia. |
| 4136 | Computer #13 |
Cortical GluCEST in Schizophrenia and Youth at Clinical High Risk for Psychosis |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Psychiatry, University of Pennsylvania, Philadelphia, PA, United States |
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In this glutamate Chemical Exchange Saturation Transfer (GluCEST) study, typically developing individuals and youth at clinical high risk for psychosis exhibit subtle, but significant, abnormalities in brain glutamate, similar to patients with schizophrenia in the entire cortical area. GluCEST technique holds distinct promise for understanding neurodevelopmental contributions to schizophrenia pathophysiology. |
| 4137 | Computer #14 |
Hippocampal metabolic abnormalities in Schizophrenia: a 3D multi-voxel MR spectroscopic imaging study |
1Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States, 2Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, NY, United States, 3Chemical Physics, Weizmann Institute of Science, Rehovot, Israel, 4Psychiatry, New York University School of Medicine, New York, NY, United States, 5Institute for Social and Psychiatric Initiatives (InSPIRES), New York University Langone Medical Center, New York, NY, United States |
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The objective of this study was to test the hypothesis that schizophrenia patients’ hippocampi are metabolically different from healthy controls’. Twenty-four patients and seven controls were studied with proton MR spectroscopic imaging at 3 T. Hippocampal volumes were also obtained. The findings were increased choline concentration in patients' hippocampi compared with controls, but no statistically significant changes in n-acetyl-aspartate or total creatine. While contrary to previous (mostly single-voxel) proton MR spectroscopy studies, these findings are nevertheless consistent with neuropathology reports of neither gliosis nor net neuronal loss. Bilateral hippocampal volume was 10% lower in the patients, consistent with previous reports. |
| 4138 | Computer #15 |
Altered cortical thickness related to the SNPs on the major histocompatibility complex in never-medicated schizophrenia |
1Radiology, West China Hospital of SiChuan University, Chengdu, China, People's Republic of |
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In summary, the present study provided evidence that single nucleotide polymorphisms（SNPs) on the major histocompatibility （MHC） relate with cortical thickness deficits in several regions，which support the critical role of immune system in the pathology of schizophrenia via modulation the development of the cerebral cortical structure. |
| 4139 | Computer #16 |
Reduced clustering co-efficient in structural connectivity of schizophrenia patients analyzed using diffusion tensor imaging |
1University of Iowa, Iowa City, IA, United States |
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Schizophrenia is a psychiatric illness characterized by failure of functional integration. To shed light on the underlying pathophysiology, the complex networks of the brain have to be studied comprehensively. This study used network analysis tools to study the topological features of the brain in schizophrenia. Using diffusion tensor imaging, we generated the graph network of schizophrenia patients and controls. We defined 68 cortical regions as nodes and used streamlines derived from deterministic fiber tracking to define the edges of the graph. A permutation testing was used to test differences between topological measures derived from the graphs of schizophrenia patients and controls. |
| 4140 | Computer #17 |
Reduced amygdala and hippocampal fractional anisotrophy in methamphatamine use with psychosis |
1The Affiliated Ningbo Medical Treatment Center Lihuili Hospital of Ningbo University, Ningbo, China, People's Republic of, 2Ningbo Addiction Research and Treatment Center, Ningbo, China, People's Republic of, 3Institute of psychology, Chinese academy of sciences, Beijing, China, People's Republic of |
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This study detected microstructural changes of amygdala and hippocampus in methamphetamine(METH) users with psychosis by analyzing FA index on diffusion weighted imaging, while these users presented no evident volume reduction in these 2 structures. These 2 structures play a vital part in METH psychosis |
| 4141 | Computer #18 |
Age-related abnormalities of the corpus callosum in autism spectrum disorder: A diffusion spectrum imaging study using template-based tract-specific analysis |
1School of Medicine, National Taiwan University, Taipei, Taiwan, 2Institute of Medical Device and Imaging, National Taiwan University, Taipei, Taiwan, 3Department of Psychiatry, National Taiwan University College of Medicine, Taipei, Taiwan, 4Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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The corpus callosum (CC) has been the most investigated white matter tract in autismspectrum disorder (ASD). However, whether the development of the CC is altered in ASD is not clearly identified. In this study, we performed diffusion spectrum imaging using tract specificanalysis to measure the generalized fractional anisotropy of 16 segments of the CC. A GFA–age hyperbolic model was applied to test the age effect. The CC connecting bilateral temporal lobes was signficantly different between ASD and TD. Our results identify the unique time trajectory of the CC in ASD. |
| 4142 | Computer #19 |
Application of the Mahalanobis Distance for Depicting the Neuroanatomical Variability within Autism Spectrum Disorders |
1Waisman Center, University of Wisconsin-Madison, Madison, WI, United States, 2McLean Hospital, Boston, MA, United States, 3University of Utah, Salt Lake City, UT, United States, 4Brigham Young University, Provo, UT, United States |
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To date, the heterogeneity of neuroimaging findings has made it challenging to identify specific brain-related phenotypes within autism spectrum disorder (ASD). In particular, a quantitative index of individual deviation across a set of brain measurements may be informative for constructing distributions of brain variation and identifying individuals who may or may not have abnormal brain structure. To this end, we investigated the use of the Mahalanobis distance to characterize multidimensional brain measures in individuals with and without ASD and to demonstrate that patterns of brain features distinguishing individuals with ASD are multidimensional and likely encompass differing cortical and sub-cortical characteristics. |
| 4143 | Computer #20 |
One-Class Classifiers detect a specific endophenotype in young children with Autism Spectrum Disorders |
1National Institute of Nuclear Physics, Pisa, Italy, 2University of Sassari, Sassari, Italy, 3University of Pisa, Pisa, Italy, 4IRCCS Stella Maris Foundation, Pisa, Italy |
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Binary classifiers are widely used to analyze brain MRI features and to identify useful biomarkers of pathology. Strong challenges arise when dealing with extremely heterogeneous conditions such as Autism Spectrum Disorders (ASD). We propose the use of the One-Class Classifier (OCC) method that, in contrast to two-class classification, is based on the description of the positive class only. A test of similarity of new cases to the positive examples is then performed, and they are eventually considered as outliers. The application of OCC to Freesurfer-based brain MRI features identified a specific endophenotype in young children with ASD. |
| 4144 | Computer #21 |
Identification of Novel Gene-Specific Bioimaging Markers in Autism Spectrum Disorder |
1Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States, 2Department of Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States |
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Autism spectrum disorder (ASD) is a complex genetic neurodevelopmental disorder. Differential expression patterns, splice-variants, and mutations in Neurexin1 (Nrxn1) have been implicated in the neurodevelopment of ASD. New targeted genome editing technologies have yielded the first cogent genetic animal models of ASD with animals harboring biallelic deletions of Nrxn1, allowing for the assessment of gene-specific perturbations in white matter composition and organization. Interrogating changes in brain structure attributable to a specific genetic allele is the first step towards the development and validation of an objective imaging biomarker, which can contribute to the diagnosis of ASD. |
| 4145 | Computer #22 |
Abnormal brain structure is associated with depression and anxiety in obese patients using DTI |
1Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, 2Department of Psychiatry, Chang Gung Memorial Hospital, Chiayi, Taiwan, 3Tiawan Center for Metabolic and Bariatric Surgery, Jen-Ai Hospital, Taichung, Taiwan, 4Department of Psychology, Chung Shan Medical University, Taichung, Taiwan, 5Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan |
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Since there is more and more delicious food in our daily life, people cannot resist the attraction to food. Therefore, obesity has become an important issue in modern society. Previous studies used food pictures to stimulate obese patients and used functional MRI to find the brain regions with increased activity. However, few studies mentioned about particular brain structure changes in obese patient. Noninvasive diffusion tensor imaging (DTI) are able to observe the water diffusion in the brain on the microscopic level for the early detection of white matter structural changes. Therefore, we used DTI to find the differences of brain structures between obese patients and healthy controls. The correlation between clinical and the DTI indices were also calculated and discussed. The clinical indices included body mass index (BMI), and measures of anxiety and depression. |
| 4146 | Computer #23 |
Mapping Cerebral Oxidative Metabolism of Oxygen in Patients with Post-Stroke Apathy |
1Radiology, Stony Brook University School of Medicine, Stony Brook, NY, United States, 2Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States, 3Psychiatry, Stony Brook University School of Medicine, Stony Brook, NY, United States |
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Five post-stroke apathy patients underwent simultaneous 18F-FDG-PET/MRI to determine brain metabolic rates. PET data was used to determine whole brain metabolic rate of glucose (MRGlu). Quantitative BOLD and arterial spin labeling MRI was used to determine cerebral metabolic rate of oxygen (CMRO2). Metabolic rates were compared for the two modalities to determine useful information associated with post-stroke apathy. The prefrontal cortex showed decreased metabolic rates for both CMRO2 and MRGlu potentially indicating apathy. MR qBOLD-derived CMRO2 measurements demonstrated good correlation with PET 18F-FDG metabolism, providing strong support for its adoption as a non-invasive mapping of brain metabolism in patients with post-stroke apathy. |
| 4147 | Computer #24 |
Cerebellar microstructural abnormalities in bipolar depression and unipolar depression: a diffusion kurtosis and perfusion imaging study |
1Jinan university, Guangzhou, China, People's Republic of, 2Guangzhou, China, People's Republic of |
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Depression in the context of bipolar disorder (BD) is often misdiagnosed as unipolar depression (UD), leading to mistreatment and poor clinical outcomes. However, little is known about the similarities and differences in cerebellum between BD and UD. Patients with BD (n = 35) and UD (n = 30) during a depressive episode as well as 40 healthy controls underwent diffusional kurtosis imaging (DKI) and three dimensional arterial spin labeling (3D ASL). The DKI parameters including mean kurtosis (MK), axial kurtosis(Ka), radial kurtosis (Kr),fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (Da) and radial diffusivity (Dr) and 3D ASL parameters (i.e. cerebral blood flow) was measured by using regions-of-interest (ROIs) analysis in the superior cerebellar peduncles(SCP), middle cerebellar peduncles (MCP) and dentate nuclei (DN) of cerebellum. Patients with UD exhibited significant differences from controls for DKI measures in bilateral SCP and MCP and cerebral blood flow (CBF) in bilateral SCP and left DN. Patients with BD exhibited significant differences from controls for DKI measures in the right MCP and left DN and CBF in the left DN. Patients with UD showed significantly lower MD values compared with patients with BD in the right SCP. Correlation analysis showed there were negative correlations between illness duration and MD and Dr values in the right SCP in UD, and negative correlations between illness duration and CBF in bilateral SCP in BD. Our findings provide new evidence of microstructural changes in cerebellum in BD and UD. The two disorders may have overlaps in microstructural abnormality in MCP and DN during the depressive period. Microstructural abnormality in SCP may be a key neurobiological feature of UD. |
| Exhibition Hall | Wednesday, May 11, 2016: 17:00 - 18:00 |
| 4148 | Computer #25 |
Abnormal brain volume and shape are associated with aspects of inhibitory control and implicit attitude toward betel nut in chewers |
1Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, 2Department of Psychology, Chung Shan Medical University, Taichung, Taiwan, 3Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan |
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Betel nut is the seed of the betel palm, which grows in the tropical or subtropical regions, especially in Taiwan, India, China and parts of east Africa. It has been confirmed that chewing betel nuts can be addicted to it and is also carcinogenic to humans. Chewing betel nuts lead to a greatly increased risk of developing a range of serious diseases, including oral and esophagus cancers. In Taiwan, 88% of people who were diagnosed to oral cancer have the habit of chewing betel nuts, but very few researches studied on how chewing betel nuts effects brian structure. Therefore, in this study we tried to find out the structural volume and shape changes in the brain between betel nut chewers and healthy controls with voxel-based morphometry (VBM) and vertex-wise shape analyses. In addition, the relationship between brain structural volume size and implicit attitude or inhibitory control were also discussed. |
| 4149 | Computer #26 |
Glutamate level change in anterior cingulate elicited by alcohol cues in alcohol use disorder |
1Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States, 2School of Health Sciences, Purdue University, West Lafayette, IN, United States, 3Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States |
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Evidence indicates that glutamate neurotransmission plays a critical role in alcohol and other substance addiction. This study investigated the dynamic change of glutamate level elicited by alcohol cues in individuals with alcohol use disorder (AUD). Both the absolute value of glutamate concentration and its ratio to total creatine measured decreased significantly for AUD subjects after they viewed the pictures of alcoholic beverages. A high correlation (r = -0.90) between baseline glutamate level and alcohol problem counts was observed for AUD subjects. This cue induced decrease of glutamate is not a direct translation from animal studies. |
| 4150 | Computer #27 |
Disadvantage of social sensitivity: Interaction of oxytocin receptor genotype (OXTR rs53576) and childhood maltreatment on limbic gray matter |
1Department of Clinical Radiology, University of Muenster, Muenster, Germany, 2Department of Psychiatry, University of Muenster, Muenster, Germany, 3Department of Psychiatry, University of Marburg, Marburg, Germany, 4Department of Psychosomatics and Psychotherapy, University of Leipzig, Leipzig, Germany, 5Department of Psychiatry, University of Wuerzburg, Wuerzburg, Germany, 6Department of Psychology, University of Muenster, Muenster, Germany, 7Department of Psychology, University of Freiburg, Freiburg, Germany, 8Freiburg Brain Imaging Center, University of Freiburg, Freiburg, Germany, 9School of Medicine, Discipline of Psychiatry, University of Adelaide, Adelaide, Australia |
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Oxytocin is a pro-social and anxiolytic neuropeptide, especially if the G-allele of a common polymorphism (rs53576) in the oxytocin receptor gene is present. Recent studies suggest, however, a detrimental role of this allele in the context of childhood maltreatment. Structural MRI data show reduced gray matter volumes of the ventral striatum, fMRI shows increased amygdala responsiveness associated with increased CTQ (maltreatment) score. Thus for individuals with adverse childhood experiences the G-allele may be a vulnerability factor. |
| 4151 | Computer #28 |
Differences in the structural brain network analysis between internet addicted adolescents and healthy adolescents |
1Department of Biomedical Engineering, Yonsei University, Wonju, Korea, Republic of, 2Department of Radiological Science, Yonsei University, Wonju, Korea, Republic of, 3Department of Radiology, Korea University Ansan Hospital, Ansan, Korea, Republic of |
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Although Internet addiction (IA) has been increasingly considered as a serious public health issue for adolescents, its neurobiological mechanisms remain poorly understood. Therefore, new biomarkers are needed to understanding IA. Using diffusion tensor images for IA and healthy adolescents, we analyzed brain network to reveal structural alterations in brain of IA adolescents. IA adolescents showed increase of regional efficiency in bilateral superior orbitofrontal cortex, right rectus and parahippocampal gyrus. Severity of IA is correlated with regional efficiency of brain regions which showed differences between groups. The brain network analysis can be used to disclose potential functional deficits in IA. |
| 4152 | Computer #29 |
Alteration of white matter microstructure within the reward circuit revealed by neurite orientation dispersion and density imaging (NODDI) |
1The Department of Radiology, The University of Tokyo, Tokyo, Japan, 2The Department of Neuropsychiatry, The University of Tokyo, Tokyo, Japan, 3The Department of Radiological Technology, The University of Tokyo Hospital, Tokyo, Japan, 4The Department of Radiology, Teikyo University School of Medicine, Tokyo, Japan, 5Office for Mental Health Support, Division for Counseling and Support, The University of Tokyo, Tokyo, Japan |
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This study aimed to investigate the brain microstructural alteration in patients with major depressive disorder (MDD) using neurite orientation dispersion and density imaging (NODDI). Nineteen MDD patients and 13 controls were involved. The TBSS analyses revealed significant increase in orientation dispersion index (ODI) in patients with MDD, distributed in bilateral frontal lobes and right occipital lobe, right internal capsule, bilateral thalamus and hypothalamus, right nucleus accumbens, and midbrain tegmentum, suggesting involvement of the reward circuit. The neurite density was not significantly altered, arousing interest on further study focusing on treatment response, whether the ODI increase is reversible or not. |
| 4153 | Computer #30 |
Alterations of neural correlates in drug-naïve first episode pediatric patients with posttraumatic stress disorder: An optimized voxel-based morphometry study |
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China, People's Republic of |
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The current study used voxel-based morphometry (VBM)-diffeomorphic anatomical registration through exponentiated lie algebra (DARTEL) algorithm to investigate the gray matter abnormalities in drug-naïve first-episode pediatric patients with posttraumatic stress disorder (PTSD) using high resolution structural MRI. Meanwhile, we investigated the association between altered neural correlates and symptom severity as measured by clinician-administered PTSD scale (CAPS) and PTSD checklist (PCL) scores with the age as a covariate. The current study provided the preliminary evidence that the intrinsic abnormalities of neural correlates in pediatric PTSD patients were mainly in fear circuit and default mode network. |
| 4154 | Computer #31 |
Altered whole brain functional connectivity in drug-naive patients with obsessive–compulsive disorder: A resting-state functional magnetic resonance imaging study |
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 2Department of Psychiatry, West China Hospital of Sichuan University, Chengdu, China, People's Republic of |
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We analysis whole brain connectivity in a relatively large sample of drug-naive patients with obsessive-compulsive disorder (OCD) using a novel graph-theory approach known as functional connectivity strength (FCS) to identify brain regions displaying high-degree centrality of connectivity. Based on the new approach of FCS, our findings demonstrated obvious significant hyperactivity of default mode network (DMN) in OCD patients at resting state. Furthermore, our results provided evidence that besides the prevailing model of cortical–striatal–thalamic–cortical circuits in OCD, the disequilibrium between the DMN and the salience network (SN) might be associated with the pathophysiology of OCD. |
| 4155 | Computer #32 |
Altered Intrinsic Brain Functional Connectivity in Suicidal Patients with Major Depressive Disorder |
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 2State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China, People's Republic of, 3Department of Nuclear Medicine, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 4Department of Psychiatry, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 5Department of Psychology, School of Public Administration, Sichuan University, Chengdu, China, People's Republic of |
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The underlying neural correlates of suicide attempts in major depressive disorder (MDD) at the connectivity or circuit level remains incompletely understood. Therefore, we utilized a graph-theory approach—functional connectivity strength (FCS) to identify resting-state functional connectivity alterations of whole-brain networks in MDD patients with a history of suicide attempts. Relative to healthy controls, two MDD patient groups (attempters and non-attempters) showed overlapping reduced FCS in the middle and inferior occipital gyrus (IOG), insula, superior temporal gyrus, thalamus and limbic regions, while attempters showed more decreased FCS in right insula and left IOG. The depression severity was positively correlated with FCS in right thalamus in suicide attempters. Disconnection of the insula and IOG could be biological correlates of impaired decision making and emotional information processing in MDD patients with a history of suicide attempt. |
| 4156 | Computer #33 |
Functional connectivity and neuroanatomical differences in a stress susceptible and resilient mouse model |
1Radiology, Translational and Molecular Imaging Institute at Mount Sinai, New York, NY, United States, 2Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 3Radiology & Psychiatry, Translational and Molecular Imaging Institute at Mount Sinai, New York, NY, United States |
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We studied functional and structural connectivity in a stress susceptible and resilient mouse model using rsfMRI and DTI. We also investigated the integrity of the Blood Brain Barrier using Gd-DTPA. We found hyperactivity in the susceptible mice which had also several regions in the brain with compromised BBB. We also detected increased structural connectivity in the resilient mice. |
| 4157 | Computer #34 |
Altered Dynamic Functional Connectivity of Amygdala in Major Depressive Disorder |
1Radiology, The Second People's Hospital of Yibin, Yibin, China, People's Republic of, 2West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 3Beijing Normal University, Beijing, China, People's Republic of |
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Neuroimaging studies have shown that MDD is accompanied by functional abnormalities in amygdala and related connections; yet, little is known about amygdala subregion dynamic functional connectivity alterations of the whole-brain networks in MDD patients. In this work, general linear model analysis were used to assess the between-group differences of amygdalar subregion dynamic functional connectivity alterations in MDD patients. We found the altered amygdaloid projection were mainly in brainstem, cerebellum, thalamus, temporal and orbital cortical areas. These areas belong to limbic-thalamo-cortical circuitry which play important role in MDD and may associated with the impaired emotional modulation ability in MDD. |
| 4158 | Computer #35 |
Increased pregenual anterior cingulate glucose and lactate concentrations in major depressive disorder |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Department of Psychiatry, Psychotherapy and Psychosomatics, Hospital of Psychiatry, University of Zurich, Zurich, Switzerland, 3Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 4Department of Psychiatry, Charité, Berlin, Germany |
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Proton magnetic resonance spectroscopy (1H-MRS) was used to test whether patients with major depressive disorder have increased glucose and lactate levels in the pregenual anterior cingulate cortex (PACC) compared to healthy controls. Therefore, forty healthy and depressed participants spectra were acquired from the PACC using a maximum echo JPRESS protocol. Results show significant increases of glucose and lactate in patients, which are also associated with depression severity. These findings indicate impaired brain energy metabolism in MDD with increased fraction of energy utilization via glycolysis and reduced mitochondrial oxidative clearance of lactate. |
| 4159 | Computer #36 |
Increase of grey matter following bifrontal rTMS in drug resistant major depressive disorder patients: A VBM study |
1Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland, 2Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, 3Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland, 4Department of Psychiatry, Kuopio University Hospital, Kuopio, Finland |
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Repetitive transcranial magnetic stimulation (rTMS) is able to induce long-term excitatory and inhibitory effects on cortical functions if applied repeatedly over several days. Thus, rTMS possesses a great potential in therapeutic applications and several promising therapies have already been developed. Whether rTMS causes structural neuroplasticity, however, remains mainly unknown. In this study, we found that bifrontal rTMS applied to dorsolateral prefrontal cortex (DLPFC) elicited structural changes in major depressive disorder patients. The increase in grey matter was found in the right post- and precentral gyri, which are both functionally connected to DLPFC. |
| 4160 | Computer #37 |
Neurochemical alterations detected in Irritable Bowel Syndrome using 2D L-COSY |
1Queensland University of Technology, Brisbane, Australia, 2The University of Newcastle, Newcastle, Australia, 3The University of Queensland, Brisbane, Australia, 4Translational Research Institute, Brisbane, Australia |
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IBS is a characterised intermittent chronic abdominal pain and altered bowel habit in the absence of an organic cause. Neurochemical changes may play a role in the pathophysiology of IBS. Our pilot studies indicate that in vivo neuro 2D L-COSY monitors alterations to neurochemical pathways associated with IBS. |
| 4161 | Computer #38 |
Amygdala down-regulation with fMRI neurofeedback in healthy subjects and BPD patients |
1Neuroimaging, Central Institute of Mental Health, Mannheim, Germany, 2Department of Psychosomatic Medicine and Psychotherapy, Central Institute of Mental Health, Mannheim, Germany |
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fMRI neurofeedback on emotion-related brain activation via a brain-computer interface can improve brain self-regulation. We could show that neurofeedback is associated with amygdala down-regulation and alterations in frontolimbic functional connectivity in healthy female participants and female patients with borderline personality disorder. Real-time fMRI neurofeedback may in future help patients with severe emotion dysregulation to improve control over emotion-related brain networks. |
| 4162 | Computer #39 |
White matter microstructure is associated with auditory and tactile processing in children with and without sensory processing disorder |
1University of California in San Francisco, San Francisco, CA, United States |
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Sensory processing disorders (SPD) affect 5-16% of school-aged children, and can cause downstream deficits of intellectual and social development. In this study, we use diffusion tensor imaging to study a cohort of 41 children with SPD and 41 typically developing children ages 8-12. We confirm and generalize results from our prior pilot study indicating disrupted posterior white matter in SPD, and further demonstrate a relationship between direct measurements of tactile and non-linguistic auditory function and white matter microstructure -- not just in SPD, but also in typically developing children. |
| 4163 | Computer #40 |
Intra-hippocampal Diffusion Tensor Imaging Identifies Dendritic Abnormalities After Early-life Stress |
1Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, United States, 2Pediatrics, Loma Linda University, Loma Linda, CA, United States, 3Neurosugery, University of California, Los Angeles, Los Angeles, CA, United States, 4Neurology, University of California, Irvine, Irvine, CA, United States, 5Pediatrics, University of California, Irvine, Irvine, CA, United States |
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The effects of early-life adversity observed in the brain anatomy of rodents might be instructive about the human condition. Chronic early life stress in a rodent model results in dendritic paring in the dorsal hippocampus. High resolution volumetric MRI found hippocampal volume loss and DTI measures of microstructure found increased fractional anisotropy. Structural MRI measures can be used to find microstructural abnormalities related to dendritic morphological abnormalities. Thus, MRI metrics could be subsequently tested clinically to monitor adolescents at risk for neuropsychiatric illness. |
| 4164 | Computer #41 |
Sensitivity of MT and T1 VBM to subcortical morphometric alterations in adult ADHD |
1Brighton & Sussex Medical School, Brighton, United Kingdom |
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Attention Deficit Hyperactivity Disorder (ADHD) is robustly associated with striatal abnormalities in childhood, though results in adults have been less definitive. Whilst this may reflect maturational normalisation, studies in adults have also typically been smaller. To enhance sensitivity to such changes we employ VBM analysis to MT saturation maps in adult ADHD, which have been shown to enhance localisation and segmentation of subcortical structures. In comparing these results to VBM analysis performed with T1 images in the same subjects, we show that MT-VBM is sensitive to striatal morphometric alterations that are not detected using T1-VBM. |
| 4165 | Computer #42 |
Assessment of chemotherapy-induced brain volume and shape changes in breast cancer patients using voxel-based morphometry and vertex-wise shape analysis |
1Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, 2Department of Psychiatry, Chang Gung Memorial Hospital, Chiayi, Taiwan, 3Department of Breast Surgery, Taichung Veterans General Hospital, Taichung, Taiwan, 4Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan |
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Recent advances in breast cancer treatment have improved the long-term survival rate in cancer patients. The success in primary breast cancer treatment marks the importance of the post-treatment care. Cancer-related trauma after chemotherapy have been widely reported by breast cancer survivors. Previous study showed the decreased gray matter volume one month after chemotherapy completion, especially in frontal regions which is known for cognitive function. Another study indicated that there is reduction in cerebellar regions and right thalamus after the chemotherapy. However, several studies focused on the change of brain volume, but did not mention about the change of brain shape. Thus, in the study we aim to find out the differences of both brain volume and shape between chemotherapy-treated breast cancer patients and healthy subjects based on voxel-based morphometry (VBM) and vertex-wise shape analysis, respectively. In our results, reduced gray matter volume of right thalamus and white matter volume of cerebellum, and altered shape of left amygdala, bilateral thalamus, and bilateral hippocampus was found in the chemotherapy-treated breast cancer patients compared to normal controls. |
| 4166 | Computer #43 |
Neurobiological Quantification of Stress-Induced Sleep-Perturbation in Rats using In Vivo Proton MR Spectroscopy and In Vitro Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) |
1Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2MR Core Laboratory, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea, Republic of, 3Department of Psychiatry, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea, Republic of, 4Biomedical Research Center, Asan Institute for Life Sciences, Asan Medical Center University of Ulsan College of Medicine, Seoul, Korea, Republic of, 5Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea, Republic of |
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The aim of this study was to quantitatively assess the differences on the cerebral metabolites and to identify factors determining the alterations of endogenous biomolecules on stress-induced sleep disturbance in rats using in vivo 1H-MRS and in vitro LC-MS/MS. The GABA, Gln concentrations, Gln/Glu, Gln/tCr, and GABA/Glu ratios were significantly higher in SSP rats than in CNTLs. The serotonin concentrations were significantly lower in SSP rats than in CNTLs. Our in vivo 1H MRS and in vitro LC-MS/MS results suggest that the various metabolites and endogenous biomolecule signals in hippocampal region are particularly sensitive and vulnerable to stress-induced sleep perturbation. |
| 4167 | Computer #44 |
Quantitative prediction of symptom progression in drug-naive individuals with obsessive-compulsive disorder using resting-state functional magnetic resonance imaging |
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China, People's Republic of, 2Department of Psychosis Studies, Institute of Psychiatry, King’s College London, London, United Kingdom, 3Department of Psychiatry, West China Hospital of Sichuan University, Chengdu, China, People's Republic of |
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Neuroimaging techniques hold the promise that they may one day aid the clinical assessment of individual psychiatric patients. However, the vast majority of studies published so far have been based on average differences between groups. The current study aimed to apply a novel multivariate pattern analysis technique known as relevance vector regression to evaluating the potential of resting-state functional magnetic resonance imaging for making accurate predictions about symptom progression in a relatively large sample of drug-naive patients with obsessive-compulsive disorder. |
| 4168 | Computer #45 |
Parcellation of nigrostriatal and mesolimbic midbrain components in adults ADHD: Relationship to waiting impulsivity and motivation |
1Brighton & Sussex Medical School, Brighton, United Kingdom, 2Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom |
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The substantia nigra/ventral tegmental area (SN/VTA) is central to the modulation of dopaminergic networks implicated in Attention Deficit Hyperactivity Disorder (ADHD). However, little is known of its specific contribution to the disorder. Whilst motivational abnormalities and impulsivity are known to be related to the structure, it is not clear whether SN/VTA subcomponents differentially contribute to these deficits. Using diffusion MRI tractography parcellation of the SN/VTA, we show that increased waiting impulsivity in ADHD is related to the microstructure of the mesolimbic SN/VTA, whilst trait motivation is related to the nigrostriatal component. Unlike previous reports in unmedicated ADHD, we detect no motivational abnormalities in this medicated cohort. However, we report that patients who have been medicated longer show alterations in microstructure consonant with increased motivation. |
| 4169 | Computer #46 |
Longitudinal VBM of downregulation in mice with striatum-specific D2R overexpression |
1RG Translational Imaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany, 2Department of Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany, 3Department of Radiation Oncology, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany, 4Department of Pharmacology, Columbia University, New York, NY, United States |
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Striatal D2R overexpression has been linked to the pathophysiology of schizophrenia. We used longitudinal voxel based morphometry on a transgenic mouse model before and after switching off the striatal D2R overexpression using doxycycline. Longitudinal registration showed a significant volume gain after the treatment in large areas covering frontal, prefrontal, striatal and temporal regions in the animals with D2R overexpression. The areas with volume increase over time show a remarkable plasticity as a result of the D2R downregulation within three weeks and correspond largely to regions with decreased gray matter volume commonly found in VBM studies on schizophrenia patients. |
| 4170 | Computer #47 |
Brain cortical thickness abnormalities in untreated, first-episode adult patients with major depressive disorder |
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China, People's Republic of |
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The present study aimed to use surface-based morphometric analysis to characterize the alteration of cortical thickness in first-episode never-medicated adult MDD patients. 37 MDD patients and 41 healthy controls were enrolled. Results showed increased cortical thickness (p<0.05, False Discovery Rate) in left anterior and posterior cingulate cortex extending to medial superior frontal cortex, bilateral precentral cortex, left paracentral cortex, bilateral superior parietal cortex, left temporal poles, and right lateral occipital cortex in MDD patients than HC group. The data provide evidence that even early in the course of depression brain regions involved in mood regulation show cortical thickness abnormalities. |
| 4171 | Computer #48 |
Whole-brain volume alteration and its correlation with anxiety severity in patients with obsessive compulsive disorder and generalized anxiety disorder |
1Research Institute of Medical Imaging, Chonnam National University Medical School, Gwang-ju, Korea, Republic of, 2Department of Radiology, Chonnam National University Medical School, Gwang-ju, Korea, Republic of |
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Obsessive compulsive disorder (OCD) and generalized anxiety disorder (GAD) are associated with abnormalities in the processing and regulation of anxiety. The purpose of this study was to evaluate gray matter (GM) and white matter (WM) volume alterations over whole-brain structures in healthy controls vs. patients with OCD vs. GAD using voxel-based morphometry (VBM), and further to assess the correlations of the GM and WM volume variations with the scores for anxiety severity in OCD and GAD. |
| Exhibition Hall | Wednesday, May 11, 2016: 17:00 - 18:00 |
| 4172 | Computer #49 |
Multiparametric MR imaging of oxygen metabolism and angiogenesis for detection of recurrence or grade increase in glioma patients |
1Department of Neurosurgery, University of Erlangen, Erlangen, Germany, 2Department of Neurology, University Clinic of St. Pölten, St. Pölten, Austria, 3Department of Radiology, University Clinic of St. Pölten, St. Pölten, Austria |
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Early detection of recurrence is crucial in patient care, but differentiation of treatment related necrosis from recurrent neoplasm is often difficult with conventional MRI (cMRI). We evaluated the usefulness for glioma recurrence grade increase detection of a multiparametric MRI for combined exanimation of oxygen metabolism and microvessel architecture. Forty-one patients with suspected recurrent glioma and one patient under antiangiogenic therapy were examined using vascular architecture mapping (VAM) and multiparametric quantitative BOLD (mp-qBOLD). 57% of LGG-patients, 22% of glioma WHO°III, and 32% of glioblastoma patients which were diagnosed as unsuspicious showed changes in oxygen metabolism and microvasculature indicative for recurrence. |
| 4173 | Computer #50 |
MCT down-regulation contributes to reduced conversion of hyperpolarized [1-13C]-pyruvate to [1-13C]-lactate in IDH1 mutant glioma cells |
1Radiology, University of California San Francisco, San Francisco, CA, United States, 2Neurological Surgery, University of California San Francisco, San Francisco, CA, United States |
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In this study we used hyperpolarized 13C-MRS to investigate pyruvate to lactate flux in IDH1 mutant cells. We found reduced hyperpolarized [1-13C]-lactate production from hyperpolarized [1-13C]-pyruvate in IDH1 mutant cells compared to wild-type. While there was no difference in lactate dehydrogenase A activity or NAD+/NADH, IDH1 mutant cells and patient samples showed reduced expression of monocarboxylate transporters MCT1 and MCT4. Comparison of hyperpolarized [1-13C]-lactate production between IDH1 wild-type and mutant lysates confirmed that reduced MCT expression was responsible for reduced hyperpolarized [1-13C]-lactate production. Thus, our study indicates that reduced MCT expression is a metabolic feature of the IDH1 mutation. |
| 4174 | Computer #51 |
Assessment of changes in structural connectivity of the central executive network during cranial radiotherapy in children treated for medulloblastoma |
1Diagnostic Imaging, St. Jude Children's Research Hospital, Memphis, TN, United States, 2Biostatistics, St. Jude Children's Research Hospital, Memphis, TN, United States, 3Oncology, St. Jude Children's Research Hospital, Memphis, TN, United States |
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Diffusion tensor imaging from 30 childhood medulloblastoma patients were analyzed to assess changes in structural connectivity of the central executive network (CEN) in response to cranial irradiation. Significant drops in fractional anisotropy and axial diffusivity (AX) were demonstrated in most of the CEN subnetworks after irradiation. Furthermore, patients receiving the highest CRT dose had significantly decreased AX in all subnetworks of the CEN. These findings suggest significant reduction in the microstructural integrity within the CEN immediately after CRT in this population and support the use of the CEN model for evaluating changes in cerebral white matter early in therapy. |
| 4175
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Computer #52 |
Slip interface imaging: a novel MR-elastography based imaging method for assessing the surgical plane of cleavage in meningiomas |
1Radiology, Mayo Clinic, Rochester, MN, United States, 2Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States, 3Neurosurgery, Mayo Clinic, Rochester, MN, United States, 4Naval Research Laboratory, Washington, WA, United States |
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The preoperative assessment of the surgical cleavage plane at the tumor-brain interface in meningiomas is important for surgical planning. A recently developed slip interface imaging (SII) technique is uniquely capable of directly assessing the degree of tumor adherence at the tumor-brain interface. In this study, SII was applied to assess the surgical cleavage plane between the tumor and the underlying brain in meningiomas. The correlation between the SII results and the surgical plane of cleavage was statistically significant (p=0.0014). The presence of a complete slip interface suggests the tumor can be removed using a dissection plane outside the pia mater. |
| 4176 | Computer #53 |
High grade intracranial gliomas exhibit widespread impaired cerebrovascular reactivity |
1Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland, 2Department of Neuroradiology, University Hospital Zurich, Zurich, Switzerland, 3Department of Neurology, University Hospital Zurich, Zurich, Switzerland |
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Neurovascular uncoupling (false negative BOLD activation) can be found in patients with high grade gliomas. An underlying mechanism could be impaired cerebrovascular reactivity. We determined overall cerebrovascular reactivity (CVR) as well as the perifocal CVR and used a healthy control group. We applied an automated tumor masking with determination of CVR in 7 consecutive rings of 3 mm. We found an overall impaired CVR as well as significantly impaired intratumoral CVR and perifocal up to 12 mm. No such trend was found on the contralateral hemisphere, after flipping of the tumor mask. |
| 4177 | Computer #54 |
Fractional Motion Diffusion Model for Differentiation of Low- and High-Grade Pediatric Brain Tumors |
1Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States, 2Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China, People's Republic of, 3Philips Research China, Shanghai, China, People's Republic of, 4Department of Radiology, University of Illinois at Chicago, Chicago, IL, United States, 5Department of Radiology, Xinhua Hospital, Shanghai, China, People's Republic of, 6Departments of Radiology, Neurosurgery, and Bioengineering, University of Illinois at Chicago, Chicago, IL, United States |
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It has been well-recognized that the complexity of biological tissues, particularly the brain tumors with high degree of structural heterogeneity, requires more sophisticated diffusion models than a simple mono-exponential model due to the non-Gaussian behavior. Among these, a newly introduced model to MRI, the fractional motion (FM) model has been the focus of many biophysical studies at the molecular level. While the FM model has been demonstrated at the voxel-level, it has not been utilized to address a clinical question. In this study, we investigate the utility of FM model for differentiating low-grade and high-grade pediatric brain tumors. |
| 4178 | Computer #55 |
Association of Apparent Diffusion Coefficient with PFS for recurrent Astrocytoma and Generation of Maps to aid in Defining Tumor Pathology |
1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States |
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Patients with recurrent low-grade Astrocytomas may experience a large variety of clinical disease courses and outcomes. Diffusion MR imaging and its associations with patient and tumor level characteristics provide an opportunity to use images as maps of tumor aggression and therefore prognosis. This study examines the relationships between the Apparent Diffusion Coefficient (ADC), histology and progress free survival in order to develop a colormap that highlights regions of the tumor with more aggressive characteristics. The colormaps provide an easier way for neuro-oncologists and neurosurgeons to interpret ADC images that can aid them in making decisions about how to manage their patients. |
| 4179 | Computer #56 |
Whole-brain echo planar spectroscopic imaging distinguishes recurrent tumor versus pseudoprogression in glioblastoma patients |
1Department of Neuroradiology, University of Pennsylvania, Philadelphia, PA, United States, 2Department of Radiology, University of Miami, Miami, FL, United States, 3Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA, United States, 4Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States, 5Department of Hematology/Oncology, University of Pennsylvania, Philadelphia, PA, United States, 6Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom |
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Differentiating brain tumor recurrence (True Progression, TP) from treatment effect (pseudoprogression, PsP) among enhancing neoplasms following radiation therapy by non-inavsive imaging may directly inform treatment strategies, yet similar imaging patterns makes this difficult leading to invasive biopsy or repeat surgery. Three-dimensional echo-planar spectroscopic imaging (EPSI) facilitates region-of-interest analysis with high-resolution metabolic data. In this study, we compared seven patients with PsP and seven with recurrent tumor using EPSI. Higher choline was detected from the contrast-enhancing, peritumoral and distal peritumoral regions in TP patients compared to PsP. |
| 4180
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Computer #57 |
ASL, DCE, DSC and IVIM: A 4-way comparison of perfusion imaging in brain tumours |
1Centre for MR Investigations, Hull York Medical School, Hull, United Kingdom, 2Centre for MR Investigations, Hull York Medical School at University of Hull, Hull, United Kingdom, 3Hull York Medical School at University of Hull, Hull, United Kingdom, 4Hull and East Yorkshire Hospitals NHS Trust, Hull, United Kingdom |
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This study aimed to compare Intravoxel Incoherent Motion (IVIM) to more established measures of perfusion; Arterial Spin Labelling (ASL), Dynamic Contrast Enhanced (DCE) and Dynamic Contrast Susceptibility (DSC) imaging, both in tumours and white matter. Mean and 95th percentile values for f, D*, fD*, CBF, Ktrans, ve, vb, rCBV and K2 were calculated. Multiple correlations were observed. Significant correlations of note include CBF vs. fD*, vb vs. rCBV and Ktrans vs. K2. Spatial registration of the 4 different methods yielded acceptable agreement given technical differences. |
| 4181 | Computer #58 |
Myoinositol as a predictive baseline biomarker for overall survival of patients with recurrent glioblastoma treated with Bevacizumab: A 1H-magnetic resonance spectroscopy study. |
1Institute of Neuroradiology, Frankfurt am Main, Germany, 2Dr. Senckenberg Institute of Neurooncology, Frankfurt am Main, Germany, 3German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, Germany |
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Myoinositol is an organic osmolyte, with intracellular concentration changes depending on the extracellular osmolality. Since Bevacizumab reduces tumor edema, we asked whether the Myoinositol concentration changes during therapy. We used 1H-MRS to measure the Myoinositol concentrations in the tumor and contralateral control of patients with recurrent glioblastomas treated with Bevacizumab (n=30) and CCNU/VM26 (n=9). Pre-therapeutic Myoinositol concentrations in the contralateral control were predictive of overall survival in patients treated with Bevacizumab. Furthermore our data confirm that recurrent glioblastoma show a strong metabolic reaction to Bevacizumab and support the hypothesis that Myoinositol might be a marker for early tumor cell invasion. |
| 4182 | Computer #59 |
Comparison of tumor microstructure derived NODDI and DTI metrics to histopathology in different grades of brain tumor |
1Department of Radiology and Biomedical Imaging, University of California San Francisco (UCSF), San Fransisco, CA, United States, 2Indiana University, Indianapolis, IN, United States, 3Department of Pathology, University of California San Francisco (UCSF), San Fransisco, CA, United States, 4Department of Neurological Surgery, University of California San Francisco (UCSF), San Fransisco, CA, United States, 5Department of Bioengineering and Therapeutic Sciences, University of California San Francisco (UCSF), San Fransisco, CA, United States |
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New non-Gaussian measurement techniques like neurite orientation dispersion and density imaging (NODDI) that allow quantification of specific tissue microstructure features can provide meaningful biophysical indices to overcome the low specificity of DTI. In this study we applied three compartment model based NODDI and DTI to histopathology and explored the correlation with tumor cellularity between non-enhancing and contrast enhancing lesions. Unlike in normal brain where Vin represents the neurite density, it was positively correlated with tumor grade and tumor score in tissue samples from the tumor region, indicating the association of Vin with tumor cellularity. Although NODDI is not directly built on tumor, it brings parameters that were sensitive to tumor cellularity, which may complement the conventional DTI model and adds specificity. Thus NODDI, when combined with DTI, could add value in understanding the heterogeneity of tissue microstructure in brain tumors. |
| 4183 | Computer #60 |
Axial diffusivity is more sensitive in detecting white matter injury in adult survivors of childhood brain tumors: a DTI study using tract-based spatial statistics |
1Department of Radiology and Imaging Sciences, EMORY UNIVERSITY, ATLANTA, GA, United States, 2Medical Imaging Center, The Second Hospital of Wuxi, WuXi, China, People's Republic of, 3Department of Psychology & Neuroscience Institute, Georgia State University, Atlanta, GA, United States |
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White matter injury is considered as a major contributory factor of treatment-induced neurotoxicity prevalent among childhood cancer survivors. DTI study with TBSS analysis shows significantly lower FA, λ// and higher λ⊥ in survivors compared to controls. DTI indices show unmatched white matter regions with significant difference. In comparison of FA, λ// may be more sensitive to detect white matter injury. Combining analysis of DTI indices provide additional information to explore white matter injury induced by radiotherapy or chemotherapy. |
| 4184 | Computer #61 |
Diagnostic value of 2-hydroxyglutarate detection by 1H MR spectroscopy in patients with glioma |
1Brain and Spine Institute (ICM), Center for Neuroimaging Research (CENIR), F-75013, Paris, France, 2INSERM U1127/CNRS UMR7225, Sorbonne Universités, UPMC Univ Paris 06, ICM, F-75013, Paris, France, 3AP-HP, GH Pitié-Salpêtrière, Service de Neurologie 2, F-75013, Paris, France, 4Division of Neurology, Foch Hospital, Paris, France, 5Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States |
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Reliable quantification by magnetic resonance spectroscopy of the oncometabolite 2-hydroxyglutarate (2HG) has important implications in diagnosis of IDH mutation, prognosis, as well as assessment of the efficacy of anti-IDH targeted therapies. In this study, we employed two approaches for 2HG detection previously described, e.g., difference spectroscopy and optimized for 2HG detection conventional spectroscopy, in order to assess for the first time the specificity and sensitivity of the two methods, and to relate these results to the natural history and the neuroradiological status of patients with glioma. |
| 4185 | Computer #62 |
Correlated MR imaging and ultramicroscopy (MR-UM) is a tool kit to assess the dynamics of glioma angiogenesis |
1Neuroradiology, University of Heidelberg, Heidelberg, Germany, 2German Cancer Research Center, Heidelberg, Germany |
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Gliomas are malignant brain tumors that depend on neoangiogenesis. Novel imaging methods are required to assess vascularization status, treatment effects and disease progression. We developed a combined MR and optical vascularization “tool kit” to study neoangiogenesis in mouse glioma models. We use T2* post contrast imaging (iron oxide nanoparticle or Gd-based) of vascular susceptibility signals and innovative ultramicroscopy (UM) of cleared brains. T2* imaging identifies single arterioles and venules in glioma development. Correlated UM of fluorescently labeled microvessels shows typical features of pathological vessels (increased caliber, density and tortuousness). Thus, MR-UM facilitates the preclinical search for more effective antiangiogenic agents. |
| 4186 | Computer #63 |
Automatic acquisition of dynamic susceptibility contrast and dynamic contrast enhanced images using a single contrast dose |
1Radiology, Northwestern University, Chicago, IL, United States |
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In clinical settings, dynamic susceptibility contrast (DSC) and dynamic contrast enhanced (DCE) data are rarely acquired together as both require a full single dose for optimal contrast-to-noise-ratio (CNR). However, both techniques offer complementary information that aid in the assessment of tumors. Current double acquisition methods acquire the DCE scan first with a half dose to minimize leakage effects in the subsequent DSC scan, compromising both scans. Here, we demonstrate the feasibility of an automatically switching DSC-DCE scan sequence by monitoring the signal intensity of the DSC scan, allowing acquisition of both datasets with a single contrast dose. |
| 4187 | Computer #64 |
Characterization of Pediatric Brain Tumors and Treatment Effect using Magnetic Resonance Fingerprinting: Initial Experience |
1Pediatrics, University Hospitals, Cleveland, OH, United States, 2Case Western Reserve University, Cleveland, OH, United States, 3University Hospitals, Cleveland, OH, United States, 4Neurology, University Hospitals, Cleveland, OH, United States, 5Surgery, University Hospitals, Cleveland, OH, United States, 6Radiology, University Hospitals, Cleveland, OH, United States |
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This study uses magnetic resonance fingerprinting to investigate relaxometry values in pediatric and young adult primary brain tumors. Six children with primary brain tumors were scanned: 3 with low-grade tumors and 3 with high-grade tumors. T1 and T2 values of tumor were significantly different from contralateral white matter. T1, T2 quantification of tumor were also significantly different between high- and low-grade tumors. Three subjects underwent serial observations: 2 received therapy and 1 did not. Subjects that underwent surgical decompression and chemotherapy appeared to have larger changes in T1 values than those that were only observed. |
| 4188 | Computer #65 |
Assessment of Global and Regional Cerebral White Matter Changes Induced by Cranial Radiotherapy in Childhood Brain Tumor Patients Using a Structural Connectivity Network Approach |
1Diagnostic Imaging, St.Jude Children's Research Hospital, Memphis, TN, United States, 2Oncology, St.Jude Children's Research Hospital, Memphis, TN, United States |
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Global and regional cerebral white matter changes induced by cranial radiotherapy (CRT) were analyzed by comparing Pre-CRT and Post-CRT diffusion tensor imaging (DTI) from 30 childhood medulloblastoma patients using a structural connectivity network model and graph theory approaches. At the global level, global network efficiency and character path were significantly changed for the whole network. At the regional level, 17 of 82 network nodes had significantly decreased local efficiencies, and 14 of those nodes also had significantly decreased clustering coefficients. These findings suggest significant reduction in the microstructural integrity immediately after CRT in this population. |
| 4189 | Computer #66 |
Characteristics of apparent relative oxygen extraction fraction (rOEF) in human high grade glioma |
1Dept. of Neuroradiology, Technische Universität München, Munich, Germany, 2Clinic for Neurology, Technische Universität München, Munich, Germany, 3Clinic for Nuclear Medicine, Technische Universität München, Munich, Germany, 4Clinic for Nuclear Medicine, Klinikum Bayreuth, Bayreuth, Germany |
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Hypoxia plays an important role in prognosis and therapy response of cancer. This study explores the characteristics of multi-parametric measurements of relative oxygen extraction fraction (rOEF) in a sample of 36 mostly high grade glioma patients. This study confirms previous results in human glioma where rOEF values were found to increase with tumor grade but does not find a similar increase of a supposedly hypoxic tumor area with tumor grade. According to present results, high rOEF values, supposedly corresponding to a high oxygen extraction, prevail in edematous tissue with low rCBV. Whether this translates into tissue hypoxia, needs further investigation. |
| 4190 | Computer #67 |
Altered Frontal Functional Networks in Adult Survivors of Pediatric Brain Tumors |
1Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States, 2Radiology, Cancer Hospital Chinese Academy of Medical Sciences at Shenzhen, Shenzhen, China, People's Republic of, 3School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, China, People's Republic of, 4Psychology and Neuroscience Institute, Georgia State University, Atlanta, GA, United States |
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Pediatric brain tumors and associated treatment affect brain development and functional network. We investigated the functional connectivity (FC) of adult survivors of pediatric brain tumors using resting-state functional MRI and independent component analysis to better understand the neural mechanisms underlying long term cognitive outcomes of the survivors. It was found that survivors exhibited differences in the FC in executive control network, default mode network and salience network compared to demographically-matched controls with increased number of effective functional connectivities and increased FC strength in survivors compared the controls. |
| 4191 | Computer #68 |
Differentiation of Central Nervous System Lymphoma and Gliomas using Dynamic Susceptibility Contrast and Dynamic Contrast-Enhanced MRI |
1Radiology, Fujita Health University, Toyoake, Japan, 2Radiology, Fujita Health University Hospital, Toyoake, Japan, 3Toshiba Medical Systems, Otawara, Japan, 4Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University, Toyoake, Japan |
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A combination of Ktrans, Ve, and rCBV would be useful in differentiating between central nervous system lymphoma and gliomas. Dynamic contrast-enhanced MRI parameters have been successfully applied to obtain quantitative estimates of the permeability of brain tumors for characterization of the vascular microenvironment. |
| 4192 | Computer #69 |
Diffusion kurtosis imaging can efficiently assess the glioma grade, cellular proliferation and survival |
1Radiology, Tongji Hospital, Wuhan, China, People's Republic of |
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Compared with conventional diffusion metrics, the kurtosis metrics derived from DKI in the solid region of the tumors were better diagnostic factors in distinguishing HGGs from LGGs and identifying grade II, III and IV gliomas. The kurtosis metrics offered great potential to noninvasively predict the cellular proliferation of gliomas. DKI was also useful to evaluate the survival of glioma patients, and MK was a significant death risk in glioma patients. |
| 4193 | Computer #70 |
Comparison of ferumoxytol and gadolinium enhancement changes in response to Avastin in high grade glioma patients |
1Department of Neurology, Oregon Health and Science University, Portland, OR, United States, 2Department of Neurosurgery, University of Pécs, Pécs, Hungary, 3Diagnsotic Center of Pécs, Pécs, Hungary, 4Department of Radiology, University of Pécs, Pécs, Hungary |
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Ferumoxytol is an alternative, investigational, iron-based MRI contrast agent, which might be beneficial in the accurate diagnosis of treated glioma patients. In this study we investigated how gadolinium and 24 hour ferumoxytol enhancement change as a result of Avastin treatment. The enhancement volumes and normalized signal intensities before and after Avastin treatment were calculated with histogram analysis and were compared between contrast agents. Changes in enhancement volumes and in signal intensities in response to Avastin were not different between contrast agents. Ferumoxytol shows good potential in brain tumor imaging. |
| 4194 | Computer #71 |
Application of diffusion kurtosis imaging for a structural differentiation of the brain metastasis and primary glioblastomas |
1Neuroimaging, Burdenko Neurosurgery Institute, Moscow, Russian Federation, 2Institute of Neuroscience and Medicine – 4, Medical Imaging Physics, Forschungszentrum Juelich GmbH, Juelich, Germany, 3Experimental physics III, TU Dortmund University, Dortmund, Germany, 4Institute of Neuroscience and Medicine – 4, Medical Imaging Physics, Forschungszentrum Juelich GmbH, Julich, Germany, 5Faculty of Medicine, Department of Neurology, RWTH Aachen University, JARA, Aachen, Germany, 6Radiology, Krasnodar Regional Hospital, Krasnodar, Russian Federation |
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MRI allows one to detect and visualize the primary and metastatic tumours in the brain. However, conventional methods suffer from a poor contrast. In turn, it leads to a problem in proper diagnostics of the tumour origins. In the present work we demonstrated the potential of kurtosis imaging technique in the tumour differentiation of primary tumour and metastasis cancers. |
| 4195 | Computer #72 |
How much microvascular anatomy is in T1-DCE MRI? – A computerized analysis of meningioma microvasculature correlated to kinetic parameters applying the extended Tofts model |
1Department of Radiology, Universitätsklinikum Bonn, Bonn, Germany, 2Center for Pathology, Universitätsklinikum Bonn, Bonn, Germany, 3Department of Neuropathology, Universitätsklinikum Bonn, Bonn, Germany, 4Clinic for Neurosurgery and Stereotaxy, Universitätsklinikum Bonn, Bonn, Germany, 5Philips Healthcare, Best, Netherlands |
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Tissue perfusion is co-defined by anatomical factors of the microvasculature. If and how kinetic parameters of T1w dynamic-contrast enhanced (T1-DCE) MRI fit into this anatomical perfusion model, is a topic of on-going discussion. Based on the extended Tofts model (ETK) we therefore performed a focal analysis of kinetic parameters in meningioma and surgically retrieved precisely corresponding tissue specimens. Their microvasculature underwent multimodal computerized analysis. Kinetic parameters were found to correlate poorly and inconsistently with the microvascular anatomy on both an inter- and intra-individual level. |
| Exhibition Hall | Thursday, May 12, 2016: 10:30 - 11:30 |
| 4196 | Computer #1 |
Rapid high-resolution T1 mapping using highly accelerated radial steady-state free-precession acquisition |
1Electrical and Computer Engineering, The University of Arizona, Tucson, AZ, United States, 2Program in Applied Mathematics, the University of Arizona, Tucson, AZ, United States, 3Department of Medical Imaging, the University of Arizona, Tucson, AZ, United States, 4Electrical and Computer Engineering, the University of Arizona, Tucson, AZ, United States, 5Biomedical Engineering, the University of Arizona, Tucson, AZ, United States |
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A golden angle radial steady-state free-precession technique and a principle component based iterative algorithm are developed for the reconstruction of high resolution T1 maps from highly undersampled data. The total acquisition time is < 3 seconds per slice. |
| 4197 | Computer #2 |
Concentration time-course Model-based Angiogram SEparation (MASE) for dynamic contrast-enhanced magnetic resonance angiography |
1Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, Korea, Republic of, 2Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of |
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Dynamic contrast-enhanced (DCE) 3D MRA has been widely used for diagnostic assessment of vascular morphology and hemodynamics in a clinical routine. It acquires a series of time-resolved images, revealing details on contrast dynamics. To extract angiograms while eliminating unwanted background tissues, subtraction between the reference (pre-contrast) and DCE images in each time frame is typically employed. However, in the presence of non-stationary background signal transition such as subject motion and time-varying magnetic field, subtraction results in incomplete background suppression and noise amplification. Due to the inherent, subtraction sparsity in either between the reference and each dynamic image or between neighboring time frames, compressed sensing (CS) is well suited to DCE MRA to enhance spatial and temporal resolution. Nevertheless, these approaches remain suboptimal due to the inherent limitation of subtraction. In this work, we propose a new, DCE MRA method called “concentration time-course Model-based Angiogram SEparation (MASE)”, in which DCE signals in the temporal direction are directly modeled and reconstructed with sparsity priors while background signals are attenuated. |
| 4198 | Computer #3 |
Entangled Compressed Sensing for Highly Accelerated 4D Flow MRI |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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Entangled denoising (eSPARSE) was developed for highly undersampled 4D Flow MRI, combining both k-t SPARSE-SENSE and 3D-L1-Wavelets. Undersampling factors of 8 and 10 were studied in healthy volunteers. The proposed algorithm improves the reconstruction of fluid vector fields in the aorta compared to k-t SPARSE-SENSE. The relative RMSE velocity is reduced by up to 16% for an undersampling rate of R = 8 and by up to 19% for R = 10. Entangled denoising (eSPARSE) is a promising approach to accelerate 4D Flow MRI while preserving key features of the flow field. |
| 4199 | Computer #4 |
High resolution CBV assessment with PEAK-EPI and PS-SPIRiT-EPI |
1University Medical Center Freiburg, Dept. of Radiology - Medical Physics, Freiburg, Germany, 2Beckman Institute, Dept. of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 3Heart Institute and Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 4University Medical Center Freiburg, Dept. of Neuroradiology - Freiburg Brain Imaging, Freiburg, Germany |
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This work is to provide perfusion parameters such as cerebral blood volume at high spatial resolution, for detailed delineation of tumor borders and to guide stereotactic surgery biopsies in locating the most aggressive tumorous tissue. This is achieved with an k-t-undersampled EPI acquisition and PEAK-GRAPPA reconstruction. Additionally, an advanced iterative reconstruction method is developed incorporating partial separability constraint into parallel imaging with SPIRiT kernels (PS-SPIRiT). Two half-dose first-pass perfusion acquisitions in tumor patients allow direct comparison of the standard clinical protocol with the proposed acquisition and reconstruction schemes. |
| 4200 | Computer #5 |
Sliding-window Reconstruction Strategy for Accelerating the Acquisition of MR Fingerprinting |
1Center for Brain Imaging Science and Technology, Department of Biomedical Engineering, Zhejiang University, Hangzhou,Zhejiang, China, People's Republic of, 2MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China, People's Republic of |
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The original MRF method uses one spiral interleaf acquired within each time point to reconstruct one image, leading to dramatic fluctuation in the signal evolution caused by undersampling error. In this work, a sliding window is utilized to select multiple interleaves to generate one full-sampled image for each step so that the fluctuation in signal evolution could be significantly alleviated. Therefore our proposed method can reach an expected result with reduced time points. The results demonstrate that the proposed method can reduce the acquisition time from about 11s to 5.6s or even less. |
| 4201 | Computer #6 |
Improving temporal resolution in fMRI using 3D spiral acquisition and low-rank plus sparse image reconstruction |
1Department of Medicine, University of Hawaii, Honolulu, HI, United States, 2Department of Radiology and Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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Recent advances in dynamic MRI propose low-rank plus sparse (L+S) matrix decomposition for image reconstruction from reduced data acquisition. The L+S method has been successfully applied to multiple applications including cardiac MRI, perfusion, angiography and recently to denoise resting-state fMRI data, suggesting that it might be promising for improving temporal resolution in task-based fMRI. We propose to use 3D spiral acquisition, undersampled in kz-t domain, and L+S method for image reconstruction. Our results indicate that proposed approach allows 4x acceleration for the data acquisition and improved statistical significance of activation maps in the S component from an increased temporal resolution and eliminating physiological noise in the L component. |
| 4202 | Computer #7 |
Accelerated 3D Coronary Vessel Wall MR Imaging Based on Compressed Sensing with A Novel Block-Weighted Total Variation Regularization |
1Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology,CAS, Shenzhen, China, People's Republic of, 2Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States |
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Coronary vessel wall MR imaging has great potential to detect coronary plaques which can be important for heart disease diagnosis. However, the imaging is always time-consuming because it needs a large amount of data for clear vessel wall depiction. In this work, a novel method based on compressed sensing (CS) with block-weighted total variation (BWTV) was proposed to accelerate coronary vessel wall imaging. Simulation and in vivo experiment results demonstrated that the proposed method can significantly decrease the amount of data for image reconstruction without compromising the depiction of the tiny coronary vessel wall. |
| 4203 | Computer #8 |
Non-rigid Motion Correction using Localized PROPELLER and Low-Rank Minimization |
1Radiology, Stanford University, Stanford, CA, United States, 2Electrical Engineering & Computer Sciences, University of California, Berkeley, CA, United States, 3Electrical Engineering, Stanford University, Stanford, CA, United States |
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A major obstacle in MRI is artifacts from patient motion. This is especially challenging for pediatric imaging where anesthesia is often required to obtain diagnostic image quality from uncooperative patients. Thus, we developed a PROPELLER-based method to correct for non-rigid motion. Simple localized motion is estimated for each spatial region by first applying a spatial window to the image data. Low-rank minimization is used to iteratively estimate the motion without the need of determining a reference motion state and to potentially enable higher-resolution navigation. The final image is constructed via autofocusing. This approach is demonstrated in free-breathing abdominal scans of healthy and patient volunteers. |
| 4204 | Computer #9 |
MRI acceleration using correlation imaging with tissue boundary sparsity |
1Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States |
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In MRI data acquisition, gradient encoding introduces a non-uniform distribution of tissue contrast and boundary information in k-space. As a result, data correlation increases with tissue boundary sparsity from the center to the outer k-space. The presented work investigates a new approach to accelerating MRI by taking advantage of non-uniform k-space data correlation. In this approach, k-space data are collected and reconstructed in a region-by-region fashion using a previously developed high-speed imaging framework, "correlation imaging"1,2. It is demonstrated that region-by-region correlation imaging can introduce a gain over parallel imaging in imaging acceleration by utilizing more information. |
| 4205 | Computer #10 |
Projected Fast Iterative Soft-thresholding Algorithm for Tight Frames in Compressed Sensing Magnetic Resonance Imaging |
1Department of Electronic Science, Xiamen University, Xiamen, China, People's Republic of, 2Department of Mathematics, Hong Kong University of Science and Technology, Hong Kong SAR, Hong Kong, 3School of Computer and Information Engineering, Xiamen University of Technology, Xiamen, China, People's Republic of |
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Redundant sparse representations can significantly improve the MRI image reconstruction with sparsity constraint. An appropriate sparse model is very important to improve image quality even with the same sparsifying transforms and undersampled data. We propose a new fast, stable, compatible and simple iterative thresholding algorithm to solve the analysis sparse models that can obviously improve the image reconstruction for tight-frame-based sparsifying transform in compressed sensing MRI. We theoretically prove the convergence of the proposed projected fast iterative soft-thresholding algorithm (pFISTA). Numerical results show that pFISTA achieves better reconstruction than state-of-art FISTA for synthesis sparse model and more stable and compatible than the state-of-art SFISTA. |
| 4206 | Computer #11 |
On-scanner sparse sampling for high resolution structural imaging of the human brain at 7T |
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Spinoza Centre for Neuroimaging, Amsterdam, Netherlands |
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We aimed to increase spatial resolution while maintaining scanning time for 3D-T1 weighted imaging by on-scanner undersampling at 7T. A 3DT1-weighted structural scan with a resolution of 0.5 mm3 was acquired with 4 times variable poisson disc compressed sensing (CS) undersampling. For comparison, scans with resolutions of 0.5 and 0.7 mm3 were acquired, with SENSE undersampling adapted to match scanning time.The CS-reconstructed scan showed no streaking artifacts, was less hampered by noise in deep brain regions, had better contrast between gray matter and CSF and less partial voluming effects. |
| 4207 | Computer #12 |
Promoting incoherence of radial x-f point spread functions using randomly perturbed golden angles |
1FMRIB Centre, University of Oxford, Oxford, United Kingdom |
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In this work we propose a simple method for increasing the spatio-temporal incoherence of a golden angle radial time-series acquisition by mildly perturbing the golden angles with a random variable. Despite its quasi-random distribution of golden angle samples, x-f point spread function analysis reveals strong coherence along the frequency domain. When the golden angles are slightly jittered using a normal random variable with small variance, the x-f point spread functions take on a more diffuse, noise-like appearance, making the acquisition scheme more appropriate for k-t reconstruction methods relying on incoherence, while maintaining its favourable spatial properties. |
| 4208 | Computer #13 |
Accelerated Dynamic MRI Reconstruction with Sequential Low Rank Matrix Completion and Parallel Imaging |
1Radiology, Mayo Clinic, Rochester, MN, United States |
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Multi-level (uniform + non-uniform) sampling for accelerated dynamic MRI either solves a computationally expensive full regression problem, or breaks the problem into two separate steps for each sampling operator. Here, the latter approach is taken, with low-rank matrix completion used as a pre-processing step to complete the non-uniform sampling operator before SENSE reconstruction unfolds the effects of the uniform sampling operator. It is shown that both spatial and temporal resolution are retained with LRMC + SENSE in comparison with more traditional pre-processing steps. |
| 4209 | Computer #14 |
Optimized image reconstruction for high resolution cerebral blood volume mapping with Ferumoxytol |
1GE Healthcare, Calgary, AB, Canada, 2Radiology, University of Calgary, Calgary, AB, Canada, 3Biomedical Engineering, University of Calgary, Calgary, AB, Canada, 4Neurology, Oregon Health and Science University, Portland, OR, United States |
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Quantitative or semi-quantitative mapping of cerebral blood volume typically involves complex modeling of a dynamic gadolinium-enhanced acquisition. Off-label use of ferumoxytol is being explored as a mechanism for high-resolution quantification of cerebral blood volume. Acquisition involves high-resolution pre- and post-contrast T2*-weighted scans; quantification is straightforward and does not require fitting. We present a multi-echo acquisition and optimal quantification algorithm for improved detection of ferumoxytol-based blood volume measurements. Our approach provides high dynamic range and minimal noise amplification. |
| 4210 | Computer #15 |
Improved Temporal Resolution TWIST Reconstruction using Annihilating Filter-based Low-rank Hankel Matrix |
1KAIST, Daegeon, Korea, Republic of, 2Gacheon Unversity Gil Medical Center, Incheon, Korea, Republic of, 3Seoul National University Hospital, Seoul, Korea, Republic of |
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In dynamic contrast enhanced (DCE) MRI, temporal and spatial resolution can be improved by time-resolved angiography with interleaved stochastic trajectories (TWIST). However, due to view sharing, the temporal resolution of TWIST is not a true one. To overcome this limitation, we employ recently proposed annihilating filter-based low rank Hankel matrix approach (ALOHA) that interpolates the missing k-space data by performing low-rank matrix completion of weighted Hankel matrix. In vivo results showed considerably better temporal resolution than standard TWIST reconstruction. |
| 4211 | Computer #16 |
Accelerated Dynamic MRI Using Tensor Dictionaries Learning |
1School of Biomedical Engineering and Guangdong Provincial Key Laboratory of Medical Image Processing, South Medical University, Guangzhou, China, People's Republic of, 2School of Mathematics and Computer Science, Gannan Normal University, Ganzhou, China, People's Republic of |
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Conventional CS methods treat a 2D/3D image to be reconstructed as a vector. However, many data types do not lend themselves to vector data representation, and this vectorization based model may lose the inherent spatial structure property of original data and suffer from curse of dimensionality that occurs when working with high-dimensional data. In this work, we introduce a novel tensor dictionary learning method for dynamic MRI reconstruction. Numerical experiments on synthetic data and in vivo data show approximately 2 dB improvement in PSNR presented by the proposed scheme over existing method with overcomplete dictionary learning. |
| 4212 | Computer #17 |
A combined Compressed Sensing Super-Resolution Diffusion and gSlider-SMS acquisition/reconstruction for rapid sub-millimeter whole-brain diffusion imaging |
1Brigham and Women's Hospital, Boston, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3Massachusetts General Hospital, Boston, MA, United States |
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We introduce a new method for rapid acquisition of sub-millimeter whole-brain diffusion imaging. Our method combines the gSlider-SMS acquisition method and the compressed-sensing super-resolution reconstruction algorithm. We demonstrate that this proposed approach is able to increase the resolution to 860μm iso in an effective acquisition time of 12 min. |
| 4213 | Computer #18 |
Accelerating MR measurement of liver steatosis using combined compressed sensing and parallel imaging: quantitative evaluation for clinical trials |
1Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom, 2Philips Healthcare, Guildford, United Kingdom |
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We compared hepatic fat fractions quantified with accelerated magnetic resonance (MR) imaging reconstructed with combined compressed sensing and parallel imaging (CS-PI) with conventional acquisitions. Undersampled data at ratios of 2.6×, 2.9×, 3.8×, and 4.8× were prospectively acquired from eleven subjects with type 2 diabetes and a healthy control. Fat fraction maps were calculated using CS-PI and Bland-Altman analysis. Inter- and intrarater analysis was performed. The fat fractions from the accelerated acquisitions had tight 95% limits of with no bias. The fat fractions were acceptable up to a factor of 3.8×, shortening the breath-hold from 17.7s to 4.7s. |
| 4214 | Computer #19 |
Under-sampled multi-shot diffusion data recovery using total variation regularized structured low-rank matrix completion |
1Dept. of Psychiatry, University of Iowa, Iowa City, IA, United States, 2Dept. of Electrical and Computer Engineering, University of Iowa, Iowa City, IA, United States, 3General Electric Healthcare Technologies, San Francisco, CA, United States, 4Dept. of Radiology, University of Iowa, Iowa City, IA, United States |
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Multi-shot diffusion imaging holds great potential for enabling high spatial resolution diffusion imaging as well as short echo time imaging to enhance studies at higher field strengths. However, the imaging throughput of multi-shot diffusion scheme is low. To increase the efficiency, under-sampled multi-shot acquisitions can be employed. However the conventional multi-shot diffusion-weighted imaging reconstructions that rely on motion-induced phase estimates are not appropriate for such acquisitions since the phase estimates will be highly corrupted due to the under-sampling. Here we propose a new total-variation regularized reconstruction for under-sampled multi-shot diffusion data using an annihilating filter bank formulation in a weighted k-space domain. |
| 4215 | Computer #20 |
Reconstruction Using Compressed Sensing with Edge Preservation for High Resolution MR Characterization of Myocardial Infarction: In-Vivo Preclinical Validation |
1Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2Sunnybrook Health Sciences Centre, Toronto, ON, Canada |
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Multi-contrast late enhancement (MCLE)1 images offer better visualization of myocardial infarction (MI) than conventional IR-FGRE. However, current MR images either with IR-FGRE or MCLE provide an inferior spatial resolution of 1.6-2.0mm in-plane with a slice thickness of 5-8mm in the clinical setting. Characterization of infarct heterogeneity requires high spatial resolution. We propose a novel method to reconstruct MCLE images at a high spatial resolution from a highly accelerated dataset acquired prospectively with three-dimensional (3D) MCLE. The method was validated in a preclinical model, producing an isotropic resolution of 1.5mm within a single breath-hold. |
| 4216 | Computer #21 |
Accelerated MP2RAGE Imaging Using Sparse Iterative Reconstruction |
1Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG, Lausanne, Switzerland, 2Department of Radiology, University Hospital (CHUV), Lausanne, Switzerland, 3LTS5, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland |
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MP2RAGE is a T1 imaging method providing greatly reduced B1 bias as well as less T2* and PD-contributions. It requires, however, long acquisition time (standard protocol with GRAPPAx3: ~8min) which hampers its clinical application. This work proposes to use sparse iterative reconstruction techniques to shorten MP2RAGE acquisition times. Resulting images are benchmarked using contrast assessment, changes in obtained T1 values as well as evaluating the effect of undersampling on an automated brain morphometry algorithm. Acceptable penalty in image quality and morphometric outcome was achieved with up to 5-fold acceleration, yielding a measurement time of 3.8min compared to fully sampled 20min. |
| 4217 | Computer #22 |
Estimation and Correction of Systematic Bias Inherent in Sparsely Undersampled Sodium Imaging of the Human Brain at High-Field |
1Electrical & Electronic Engineering, University of Melbourne, Melbourne, Australia, 2Siemens Healthcare, Melbourne, Australia, 3Anatomy & Neuroscience, University of Melbourne, Melbourne, Australia, 4Florey Institute of Neuroscience and Mental Health, Melbourne, Australia |
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Sodium plays a vital role in various physiological processes and functions due to the delicate balance between intra- and extracellular sodium concentration. Disturbance to this electrochemical gradient is considered to be a sensitive, early indicator of cell breakdown and provide an insight into cellular integrity. Iterative reconstruction of sparsely undersampled data has been shown to cause inaccuracies in the estimation of tissue sodium content. This work investigates the bias in sodium concentration estimates and presents a method for correction that recovers the quantitative property of sodium imaging for high undersampling factors. |
| 4218 | Computer #23 |
Highly accelerated fat-fraction measurements for clinical trials in muscular dystrophy |
1Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom, 2Philips Healthcare, Guildford, United Kingdom, 3Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom |
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Fat fraction measurement in muscular dystrophy is important for therapy trials. Accelerated acquisition reconstructed by combined compressed sensing and parallel imaging (CS-PI) can improve patient compliance. Eight patients with Becker muscular dystrophy were recruited and prospectively undersampled data at ratios of 3.65×, 4.94×, and 6.42× were acquired in addition to fully sampled data. The CS-PI reconstructions were of sufficient quality at 3.65× and 4.94× acceleration. Compared to fully sampled data, non-significant bias and 95% limits of agreement of 1.65%, 1.95% and 2.22% were found for the three CS-PI reconstructions, significantly outperforming conventional parallel imaging alone. |
| 4219 | Computer #24 |
Evaluation of highly undersampled contrast-enhanced MR angiography (SPARSE CE-MRA) in intracranial applications |
1High Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany, 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany, 3Neuroradiology, University Hospital Giessen and Marburg GmbH, Giessen, Germany, 4Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany |
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Highly undersampled contrast-enhanced intracranial MR angiography (SPARSE CE-MRA) was evaluated regarding the vascular visibility and image quality in a clinical setting on a 3T MRI system for 23 patients with various pathologies. The overall performance is comparable to TOF MR angiography, yet with much shorter acquisition times and a high-resolution whole-head coverage in both arterial and venous phase. However, a strong dependence of the obtained MRA quality on the bolus timing of the contrast agent was found and needs to be properly addressed by the operators to minimize the arterio-venous overlap in the imagery for best diagnostic quality. |
| Exhibition Hall | Thursday, May 12, 2016: 10:30 - 11:30 |
| 4220 | Computer #25 |
Magnetic Resonance Imaging Cross-Modality Synthesis |
1Department of Electronic and Electrical Engineering, The University of Sheffield, Sheffield, United Kingdom, 2 Department of Computer Science and Digital Technologies, Northumbria University, Newcastle, United Kingdom |
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Multi-modality MRI protocols are becoming standard in the everyday clinical practise. The advantages of such acquisitions were shown to be fundamental in a wide range of applications, such as medical diagnosis and image segmentation. However, the implementation of these protocols tends to be time-consuming, consisting in one key limitation. In this paper we address this problem by presenting a novel method for synthesising any MRI modality from a single acquired image. This is done using machine learning techniques for dictionary learning. Results show that our approach can lead to significant performance over the state-of-the-art methods. |
| 4221 | Computer #26 |
Fast Dynamic MRI from Undersampled Acquisitions Using Weighted, Adaptive Model Consistency Reconstruction (WI-MOCCO) |
1Medical Physics, University of Wisconsin, Madison, WI, United States, 2Radiology, University of Wisconsin, Madison, WI, United States |
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We describe next generation of Model Consistency COndition (MOCCO) reconstruction which makes use of new Weighted low-rank models and attains high image quality through Iterative model adaptation to complexity of the local temporal dynamics (WI-MOCCO). |
| 4222 | Computer #27 |
Accelerating Intravoxel Incoherent Motion Imaging of the Brain using k-b PCA |
1Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland |
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In vivo Intravoxel Incoherent Motion (IVIM) parameter mapping in the brain is particularly challenging because of inherent noise amplification of parallel imaging. To address this limitation, correlations in space and in the b-value dimension may be jointly exploited. To this end, an iterative approach of k-t PCA was adapted to allow image reconstruction from undersampled IVIM data. Reconstruction and parameter estimation errors of the proposed k-b PCA approach relative to parallel imaging were assessed. Mean absolute parameter errors of k-b PCA were lower compared to CG-SENSE (R=4): 1.3±1.9·10-4/1.8±2.0·10-4 mm2/s (D) 0.068±0.083/0.085±0.101 (f) and 6.4±16.9·10-2/7.6±18.3·10-2 mm2/s (D*). It is concluded that k-b PCA is a promising alternative to parallel imaging to reduce scan times while maintaining the quality of diffusion and perfusion parameter maps in brain exams. |
| 4223 | Computer #28 |
An Improved Tissue-Fraction MRF (TF-MRF) with Additional Fraction Regularization |
1Center for Brain Imaging Science and Technology, Department of Biomedical Engineering, Zhejiang University, Hangzhou,Zhejiang, China, People's Republic of, 2MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China, People's Republic of |
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MR fingerprinting has been used for estimating the intra-voxel tissue component fractions by resolving the equation Svoxel=Dw. In this study, potential fractions of interested components are used for building dictionary instead of T1 and T2, changing the solution of Svoxel =Dw into an optimization problem with regularization terms. The results demonstrate that the proposed method could provide more robust quantification of tissue composition and estimation of partial volume effects. |
| 4224 | Computer #29 |
Effect of a Low-Rank Denoising Algorithm on Quantitative MRI-Based Measures of Liver Fat and Iron |
1Radiology, Duke University Medical Center, Durham, NC, United States, 2MR Application Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany, 3MR R&D Collaborations, Siemens Healthcare, Cary, NC, United States, 4Center for Advanced Magnetic Resonance Development, Duke University Medical Center, Durham, NC, United States |
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Applying the described low-rank denoising algorithm to a liver fat/iron quantification technique reduces image noise in PDFF and R2* maps without adversely affecting mean values of the quantitative measures or reader assessment of edge sharpness. |
| 4225 | Computer #30 |
Steady-State Magnetic Resonance Fingerprinting |
1Philips Research Europe, Hamburg, Germany |
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We propose an acceleration technique for MR Fingerprinting measurements based on Cartesian or otherwise segmented sampling. We show that quick repetition of MR Fingerprinting sequences leads to stationary signal responses. Instead of waiting for the spin system to relax completely before the start of the next fingerprint sequence, we take the evolution of the spin system into account and calculate a dictionary of steady-state fingerprints. We present a Cartesian fingerprint measurement with a SENSE factor of four. Using our method, additional acceleration by more than a factor of two could be achieved, without reducing the match accuracy. |
| 4226 | Computer #31 |
Reconstructing all physical quantities from time-domain data of a very short sequence |
1UMC Utrecht, Utrecht, Netherlands |
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Magnetic Resonance Spin TomogrAphy in Time-domain (MR-STAT) aims at reconstructing all physical quantities (T1,T2, PD, etc) directly from the data in the time-domain. By solving a large scale nonlinear inversion problem, the parameters can be inferred. The spatial encoding is entangled implicitly in the time response of the system. A very quick acquisition can be performed and processed to derive all system parameters, including electromagnetic field maps like B0 and B1. We illustrate MR-STAT at high resolution for a realistic numerical phantom and we show high precision reconstructions of quantitative maps. |
| 4227 | Computer #32 |
Acceleration of MR Fingerprinting with Low Rank and Sparsity Constraint |
1Center for Brain Imaging Science and Technology, Zhejiang University, Hangzhou, China, People's Republic of, 2MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China, People's Republic of |
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In this study, a low rank and sparsity based MRF reconstruction scheme (L&S MRF) is proposed for reducing the artifacts of each time point with a fraction of acquisition times. |
| 4228 | Computer #33 |
Highly Accelerated Chemical Exchange Saturation Transfer (CEST) MRI Using Combination of Compressed Sensing and Sensitivity Encoding |
1The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States |
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Chemical exchange saturation transfer (CEST) imaging is a unique contrast enhancement technique that enables the indirect measurement of endogenous metabolites with water-exchangeable protons. The measurement of a complete Z-spectrum using standard imaging acquisition scheme is time consuming because a large number of the RF saturation frequency offset followed by MR signal readout is inevitable to obtain the full Z-spectrum. In this study, the feasibility of accelerated CEST imaging using combined CS and SENSE technique (CS-SENSE) was demonstrated in healthy volunteers and glioma patients at 3 T. |
| 4229 | Computer #34 |
Multi-shot sensitivity encoded diffusion data recovery using structured low-rank matrix completion (MUSSELS) |
1Dept. of Psychiatry, University of Iowa, Iowa City, IA, United States, 2Dept. of Electrical and Computer Engineering, University of Iowa, Iowa City, IA, United States, 3General Electric Healthcare Technologies, San Francisco, CA, United States, 4Dept of Radiology, University of Iowa, Iowa City, IA, United States |
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Multi-shot diffusion imaging holds great potential for enabling high spatial resolution diffusion imaging as well as short echo time imaging to enhance studies at higher field strengths. Conventional reconstructions rely on motion-induced phase estimates to recover the diffusion-weighted images from multi-shot acquisitions. Since a good estimate of phase cannot be obtained in many situations either due to noisy data or high under-sampling, these methods are unreliable in such situations. Here we propose a new reconstruction for multi-shot diffusion imaging that recovers the missing k-space data of the multiple shots by formulating the recovery as a structured low-rank matrix completion problem. |
| 4230 | Computer #35 |
Two-step adaptive reconstruction of multichannel phase images |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of |
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Adaptive reconstruction (AR) can be used to combine multichannel images without acquiring coil sensitivity information. It can improve the SNRs of combined magnitude and phase images. But the reconstructed phase images may suffer from open-ended fringe artifacts when coil-sensitivity maps vary a lot. We propose a two-step adaptive reconstruction method to combine multichannel images. This method is shown to be more robust than the traditional AR method and can still maintain the high SNR. |
| 4231 | Computer #36 |
Improved Time Fidelity in Sparse ADMM Reconstruction via Tempered Data Weighting |
1Mayo Clinic, Rochester, MN, United States |
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By adding an age-of-sample dependent weighting to the data fidelity penalty of an Alternating Direction Method of Multipliers sparse reconstruction of a view-shared accelerated acquisition, improved temporal fidelity is observed in a time-resolved motion-controlled phantom study. |
| 4232 | Computer #37 |
Reference-guided CS-MRI with Gradient Orientation Priors |
1Shenzhen Institutes of Advanced Technology, Shenzhen, China, People's Republic of |
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In various MR applications, a pre-scan is usually practicable that extra morphology information can be extracted from the reference image. However, with a reference image obtained from a different contrast mechanism, the signal variation in the reference may differ from that in the target image. In this work, we propose to exploit gradient orientation information, which is closely related to the anatomical structures but less dependent on the image contrast, to enable superior CS-based reconstruction. The proposed method was validated using multi-scan experiment data and is shown to provide high speed and high quality imaging. |
| 4233 | Computer #38 |
Temporal point spread function interpretation of low rank, dictionary learning models in dynamic MRI |
1Electrical Engineering, University of Southern California, Los Angeles, CA, United States, 2Electrical and Computer Engineering, University of Iowa, Iowa city, IA, United States |
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A number of dynamic MRI applications have seen the adaptation of data-driven models for efficient de-noising and reconstruction from under-sampled data. In this work, we develop a novel temporal point spread function interpretation of two data-driven models: low rank, and dictionary-learning. Through this interpretation, we show (a) the low rank model to perform spatially invariant non-local view-sharing, and (b) the dictionary-learning model to perform spatially varying non-local view-sharing. Both the models can be viewed as efficient data-driven retrospective binning techniques. We provide demonstrations using the application of de-noising real-time MRI speech data. |
| 4234 | Computer #39 |
Kernelized Low-Rank: Improve Low-Rank with Adaptive Nonlinear Kernel for Dynamic MRI |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States |
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Low-Rank methods are widely applied to improve reconstruction for Dynamic Contrast Enhanced (DCE) MRI by imposing linear spatial-temporal correlation in global, local or multiple scales. This assumption does not fully capture the highly nonlinear spatial-temporal dynamics of DCE signals. We proposed a generalized Kernelized-Low-Rank model, assumed Low-Rank property after nonlinear transform and solved it by Regularizing singular-values with Adaptive Nonlinear Kernels. The proposed method captures the spatial-temporal dynamics as a sparser representation and achieves more accurate reconstruction results. Kernelized-Low-Rank model can be easily integrated to provide significant improvements to Global Low-Rank, Locally Low-Rank, LR+S and Multi-scale LR models. |
| 4235 | Computer #40 |
Efficient algorithm for maximum likelihood estimate and confidence intervals of $$$T_1$$$ from multi-flip, multi-echo FLASH |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Radiology, Harvard Medical School, Boston, MA, United States |
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Multi-flip, multi-echo 3D FLASH is routinely used to estimate T1. We present a novel, efficient algorithm for finding both the ML estimate and a confidence interval for T1, given full, multi-channel data from such an experiment. Finding the ML estimate is based on minimizing a cost function. The ends of the CI are a threshold value for the same cost function, where the threshold is determined via Monte Carlo experiment based on the protocol and desired confidence level. Results from a phantom study are shown, demonstrating the value of CIs in interpreting the validity of the ML estimates. |
| 4236 | Computer #41 |
Advances in Model-Based Reconstruction of High Resolution T1 maps |
1Biomedizinische NMR Forschungs GmbH, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany |
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Fast and accurate determination of T1 values can be accomplished by Look-Locker type MRI sequences. Here, we formulate T1 mapping as a nonlinear optimization problem which we subsequently solve by the iteratively regularized Gauss Newton (IRGN) method. Our choice of the model parameterization allows to exploit smoothness of the spatial flip angle distribution as additional prior knownledge. This model-based reconstruction allows accurate and precise reconstruction of high resolution T1 maps from radial, highly undersampled data as validated in phantom studies and demonstrated in the human brain. |
| 4237 | Computer #42 |
Whole-Brain Gray Matter Imaging Exploiting Single-Slab 3D Dual-Echo TSE With Relaxation Modulation: Comparison With Double Inversion Recovery Gray Matter Imaging |
1Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Korea, Republic of, 2Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of |
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In this work we propose a novel, GM-selective single-slab 3D dual echo TSE with relaxation modulation (no long IR), in which white matter signals remain nulled before signal encoding while CSF signals are modulated to be cancelled during residual reconstruction between echoes with sparsity prior. We demonstrate the effectiveness of the proposed method over conventional DIR in that the former can achieve 1mm-isotropic whole-brain GM acquisition in 5-6 min. without apparent artifacts. |
| 4238 | Computer #43 |
Dynamic Tagged Liver MRI Exploiting Tag-Constrained Sampling and Separation: Assessment of Liver Stiffness |
1Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, Korea, Republic of, 2Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of |
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It is important to assess liver stiffness and monitor the progression of fibrosis in patients with liver diseases using non-invasive imaging. Exploiting the fact that the motion of the heart during cardiac cycle is an intrinsic driving source to deform the liver, dynamic tagged MRI can be employed to measure the cardiac motion induced displacements using harmonic phase images and thereby evaluate the corresponding strain maps in the liver. In this work, we propose a novel framework of compressed sensing (CS) for dynamic tagged liver MRI, in which: 1) data is acquired using tag-constrained, incoherent undersampling in k-t space, 2) a time series of morphologies is decomposed into transient tag-only images and stationary tag-free liver images, 3) both morphological components are then reconstructed directly from the tag-constrained, undersampled k-t space, and 4) the transient tag-only images are employed to estimate time-varying displacements and the corresponding strain maps while the stationary tag-free liver images are used as a structural roadmap. |
| 4239 | Computer #44 |
Dynamic Contrast-Enhanced MRA with Robust Background Suppression Exploiting Motion Subspace Learning and Sparsity Priors |
1Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, Korea, Republic of, 2Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of |
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Dynamic contrast-enhanced magnetic resonance angiography(DCE-MRA) has been widely used for diagnostic assessment in clinical practices. To enhance the conspicuity of arteries relative to unwanted background tissues, subtraction between the pre-contrast and the post-contrast images was typically performed displaying maximum intensity projection images(MIP). Nevertheless, if there exists non-stationary signal transition due to time-drifting field inhomogeneity, and subject motion etc, the subtraction leads to incomplete background suppression, impairing the detectability of arteries as well as small vessel particularly at high reduction factors. In this work, we propose a novel DCE-MRA method exploiting motion subspace learning and sparsity priors for robust angiogram separation, in which the motion subspace is learned using partial Casorati matrix without any motion information while image reconstruction with sparsity priors is performed to jointly estimate motion-induced artifacts and DCE angiograms of interest under the framework of the decomposition. Simulation and experimental studies show that the proposed method is highly competitive with the competing methods including subtraction and fast reconstruction techniques. |
| 4240 | Computer #45 |
High Spatiotemporal Resolution 3D Dynamic MRI using Spiral Acquisition and Compressed Sensing with L0 Homotopic Minimization |
1Center for Biomedical Imaging Research, Department of Biomedical Enginnering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of, 2Institute of nuclear and new energy technology, Tsinghua University, Beijing, China, People's Republic of, 3Radiology, Weill Cornell Medical College, New York, NY, United States, 4Healthcare Department, Philips Research China, Shanghai, China, People's Republic of, 5Biomedical Engineering, Cornell University, New York, NY, United States |
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High spatiotemporal resolution 3D imaging is a desired technique for detecting dynamic information of detailed anatomy and getting accurate modeling parameters. In this abstract, we developed a method using golden angle spiral and compressed sensing with L0 homotopic minimization for high resolution 3D imaging. In this method, a high undersampling rate and high motion insensitivity can be achieved. In clinical applications such as dynamic contrast enhanced MRI, this new method is very promising to achieve high spatiotemporal resolution without breath-hold. |
| 4241
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Computer #46 |
Improved Field-Map Estimation and Deblurring for MAVRIC-SL |
1Department of Radiology, Stanford University School of Medicine, Stanford, CA, United States, 2Department of Electrical Engineering, Stanford University, Stanford, CA, United States |
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In order to image in the large B0 field inhomogeneity near metallic implants, multi-spectral imaging sequences, such as MAVRIC-SL, acquire images at multiple spectral bins to reduce distortion while imaging the entire anatomy. However, blurring is introduced when these overlapping bins are combined. While a deblurring method, which uses a field-map estimated from the bin images, does exist, the resulting images are subject to increased noise and distortion. Here we propose both a better field-map estimation method along with an improved deblurring algorithm, both of which are less sensitive to noise and help provide excellent deblurring without distortion. |
| 4242 | Computer #47 |
Free-breathing 3D Cine Whole-heart Magnetic Resonance Imaging using Compressed Sensing Parallel Image Reconstruction |
1Pediatrics, Harvard Medical School, Boston, MA, United States, 2Cardiology, Boston Children's Hospital, Boston, MA, United States, 3Arterys, San Francisco, CA, United States, 4Cardiology, Boston Children’s Hospital, Boston, MA, United States |
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We developed and evaluated a variable density Poisson disc undersampling technique and compressed sensing image reconstruction algorithm for free-breathing 3D cine steady-state free precession whole-heart imaging. In 10 patients, we found good agreement between 3D cine and conventional breath-hold 2D cine imaging measurements of ventricular volumes. |
| 4243 | Computer #48 |
Accelerated 3D coronary MRA using non-rigid motion corrected regularized reconstruction |
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom |
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Accelerated 100% scan efficiency whole-heart 3D coronary MR angiography (CMRA) is achieved by combining undersampling and non-rigid motion correction in a unified regularized reconstruction. 3D undersampled CMRA is performed using a golden-step spiral-like Cartesian trajectory. Motion correction is achieved in two steps: beat-to-beat 2D translational correction with motion estimated from interleaved image navigators, and bin-to-bin 3D non-rigid correction with motion estimated from the data itself. A generalized matrix formalism with total variation regularization is used to perform the non-rigid correction directly in the reconstruction. This approach produces good quality images, comparable to those of a navigator-gated approach, but in a ~5x shorter scan time. |
| Exhibition Hall | Thursday, May 12, 2016: 10:30 - 11:30 |
| 4244 | Computer #49 |
Impact of non-rigid registration and retrospective image correction (RETROICOR) on detecting BOLD fMRI vasomotor response in the breast |
1Department of Radiology, University of Cambridge, Cambridge, United Kingdom, 2Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom |
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Physiological fluctuations and motion artifacts are expected to be dominant sources of noise in BOLD fMRI experiments to assess tumor oxygenation and angiogenesis. This work assesses the impact of a non-rigid registration algorithm and retrospective image correction (RETROICOR) on the detection of activation signals in the breast, both at resting state and in response to a modulated respiratory stimulus paradigm. Our results suggest that correction for motion artifacts is associated with a reduction in false-positive activation effects, which can be further improved by the addition of RETROICOR, confirming the importance of these physiological corrections in functional parameter estimation. |
| 4245 | Computer #50 |
Prospective Motion Correction in Brain Imaging Using a Passive Magnetic Sensor |
1Radiology, Center for Metabolic Imaging and Therapeutics, University of Maryland, School of Medicine, Parkville, MD, United States, 2Radiology, Center for Metabolic Imaging and Therapeutics, University of Maryland, School of Medicine, Baltimore, MD, United States, 3Department of Mechanical Engineering, University of Maryland, College Park, Maryland, United States, Baltimore, MD, United States |
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We present a prospective motion correction (PMC) technique using a miniature passive magnetic sensor. The motion sensor can virtually work with any imaging technique that is sensitive to motion. Especially techniques such as fMRI, DTI and spectroscopy sequences are likely to benefit greatly when dealing with non-cooperative subjects. In this study, the GRE sequence was initially modified by adding three bipolar gradients along the read, phase, and slice-selection directions respectively. The bipolar gradients were used to trigger the position and orientation tracking sensor. A dynamic feedback loop mechanism was implemented into the sequence to receive the sensor position and orientation for real-time update of the imaging slice using an in-house developed application. We demonstrate that our PMC method in brain imaging using a passive magnetic sensor is capable of tracking the patient head motion with high accuracy. |
| 4246 | Computer #51 |
Synchronization of longitudinal multi time-point breast DCE data using a group-wise registration approach |
1GE Global Research, Bengaluru, India, 2University of Cambridge, Cambridge, United Kingdom |
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Multi-parametric longitudinal imaging is an important tool to monitor therapy response at tumor locations. The key challenge in longitudinal data is the synchronization of volumes across time points, as large variations are seen due to therapy response, weight loss/gain, patient positioning, and surgery. We employ a group-wise registration approach to synchronize the longitudinal volumes and compare/contrast it with a more typical pair-wise registration approach. Group-wise approach results in consistent registration across time-points as it does not require a reference image. The group-wise non-rigid registration approach is demonstrated on longitudinal MRI data used for assessing breast tumor therapy response. |
| 4247 | Computer #52 |
Outer volume suppression improves motion tracking and image quality in self-navigated whole heart cardiac MRI: results from a moving phantom and healthy volunteers |
1Department of Radiology, University Hospital (CHUV) / University of Lausanne (UNIL), Lausanne, Switzerland, 2Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland, 3CardioVascular Magnetic Resonance (CVMR) research centre, Centre for Biomedical Imaging (CIBM), Lausanne, Switzerland |
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In respiratory self-navigation (SN), static structures, such as the arms or chest wall, may complicate motion detection due to the superposition of signal originating from different tissues. Even if motion detection is successful, the subsequent motion correction may introduce streaking artefacts when applied to static structures. Suppressing signal from those tissues may therefore improve image quality. In this study, we address the hypothesis that SN coronary MRA will benefit from the introduction of an outer volume suppressing "2D-T -Prep", and present results from a moving cardiac phantom and 10 healthy volunteers. |
| 4248 | Computer #53 |
Reconstruction of under-sampled Propeller gradient-echo image using projection onto convex sets based multiplexed sensitivity-encoding (POCSMUSE) |
1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong, 2Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC, United States |
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The Propeller technique is a useful acquisition scheme and reconstruction method to reduce motion artifact. However, the higher specific absorption rate (SAR) of RF pulse at high-field magnetic strength can limit the number of multiple slices for a given TR, which in turn reduces the efficiency of acquisition, especially for Propeller-FSE sequence. A possible solution is to reduce the echo-train-length with under-sampling of data of each blade. In this study, we propose to apply POCSMUSE instead of SENSE reconstruction and Propeller reconstruction, to reconstruct the image from all under-sampled blade data with reduced noise amplification. The data acquired from brain and liver using Propeller-GRE will be used to test purposed POCSMUSE algorithm. |
| 4249 | Computer #54 |
Respiratory Motion Compensation for Simultaneous PET/MR Using Strongly Undersampled MR Data |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany |
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To allow for MR acquisition times as short as 1 minute per bed, we propose a new method for PET/MR respiratory motion compensation (MoCo), which is based on strongly undersampled radial MR data. We acquired simultaneous PET/MR data of the thorax of three patients. Motion vector fields were estimated with a newly-developed algorithm, which alternates between MR image reconstruction and motion estimation. Subsequent 4D MoCo PET reconstructions employing the motion vector field derived from strongly undersampled MR data yielded a considerable visual and quantitative improvement compared to standard 3D PET and 4D gated PET reconstructions. |
| 4250 | Computer #55 |
Motion Correcting Complete MR-PET Exams Via Plot Tone Navigators |
1Radiology, New York University, New York, NY, United States, 2Siemens Medical Systems, Malvern, PA, United States, 3Siemens Medical Systems, Erlangen, Germany |
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We demonstrate the use of an external RF signal as a mean to provide motion tracking information for motion-state sorting of k-space line during dynamic MRI scans. |
| 4251 | Computer #56 |
High temporal resolution retrospective motion and $$$B_0$$$ correction using FIDNavs and segmented FatNavs at 7T. |
1CIBM, EPFL, Lausanne, Switzerland, 2Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG, Lausanne, Switzerland, 3Department of Radiology, University Hospital (CHUV), Lausanne, Switzerland, 4LTS5, EPFL, Lausanne, Switzerland, 5Donders Centre for Cognitive Neuroimaging, Radboud University, Netherlands |
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FID navigators (FIDNavs) and a few lines of highly accelerated double-echo 3D fat navigators (FatNavs) were measured each TR of a high-resolution 3D-GRE acquisition. High temporal resolution $$$B_0$$$ variations and motion parameters could be estimated by the FIDNavs using the lower temporal resolution FatNavs to derive calibration data. The cardiac cycle pattern emerged clearly in these estimates and retrospectively corrected images were of clearly improved quality, thereby demonstrating the potential for this hybrid approach. |
| 4252 | Computer #57 |
Self-navigated real-time motion tracking of the abdomen in free-breathing single-shot EPI data using the Extended Kalman Filter. |
1Department of Radiology, University of California, San Diego, San Diego, CA, United States, 2Global Applied Sciences Lab, GE Healthcare, Menlo Park, CA, United States, 3Department of Neuroscience, University of California, San Diego, San Diego, CA, United States |
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Free-breathing single-shot EPI data in the abdomen is confounded by respiratory motion artifact. Previous work has demonstrated the utility of using the Extended Kalman Filter (EKF) for real-time image-based tracking of spiral-navigated scans in brain. This this study we demonstrate the feasibility of using the EKF framework for real-time self-navigated motion tracking in the abdomen. |
| 4253 | Computer #58 |
Motion-resolved 3D dynamic contrast enhanced liver MRI |
1Siemens Healthcare GmbH, Erlangen, Germany, 2Medical Imaging Technologies, Siemens Healthcare, Princeton, NJ, United States, 3Siemens Healthcare Ltd., Seoul, Korea, Republic of, 4Department of Radiology, Seoul National University Hospital, Seoul, Korea, Republic of |
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Free-breathing dynamic contrast-enhanced liver MRI is explored using a Cartesian spoiled Volume-Interpolated Breath-hold Examination (VIBE) GRE sequence that also acquires a navigation signal. Images are iteratively reconstructed using a hard-gating approach as well as resolving the motion-states using an additional dimension. With both approaches yielding promising results, the latter appears to be more motion robust at the cost of computational effort. |
| 4254 | Computer #59 |
Prospective motion correction for MRI using EEG-equipment |
1Danish Research Center for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark, 2DTU Elektro, Technical University of Denmark, Lyngby, Denmark |
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A new prospective motion correction technique is presented that is based on signals from gradient switching, in an EEG-cap with interconnected electrodes the subject wears during scanning. The method has no line-of-sight limitations as optical methods, requires no interleaved navigator modules or additional hardware for sites already doing EEG-fMRI. Instead a training scan is performed were signals recorded with the EEG-system are correlated with motion parameters estimated by image realignment. Initial results from application of the method in a phantom are promising. |
| 4255 | Computer #60 |
Motion Correction Using Orthogonal Images |
1Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH, United States, 2Small Animal Imaging Shared Resources, The Ohio State University, Columbus, OH, United States, 3Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH, United States, 4Department of Biomedical Informatics, The Ohio State University, Columbus, OH, United States |
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In most small animal imaging studies both long axis (coronal or sagittal) and short axis (axial) images of the region of interest are obtained. The goal of this study is to explore whether combining two orthogonal views obtained with different slice-select directions could reduce the motion artifacts and improve image quality. The advantages of this method are that no a priori knowledge or external hardware is needed and it doesn’t increase the acquisition time. The results show that it is advantageous to use the available orthogonal image(s) to improve the image quality by reducing ghosting artifacts caused by motion. |
| 4256 | Computer #61 |
Image Registration and Robust Fitting for Motion Insensitive Magnetic Resonance Fingerprinting (MRF) |
1Radiology, Case Western Reserve University, Cleveland, OH, United States |
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Motion is one of the biggest challenges in clinical MRI. The recently introduced Magnetic Resonance Fingerprinting (MRF) has been shown to be less sensitive to motion. However, it is still susceptible to patient motion primarily occurring in the early stages of the acquisition. In this study, we propose a novel reconstruction algorithm for MRF, which uses robust fitting and image registration algorithms to decrease the motion sensitivity of MRF. The evaluation was performed in numerical phantoms with simulated rigid motion. |
| 4257 | Computer #62 |
Dynamic, T2-Weighted, Single-Shot Fast Spin Echo with Variable Refocusing Flip Angle and Cylindrical Navigator for Retrospective Respiratory Compensation |
1Global MR Applications & Workflow, GE Healthcare, New York, NY, United States, 2Department of Radiation Oncology, Mayo Clinic, Rochester, MN, United States, 3Department of Radiology, Mayo Clinic, Rochester, MN, United States, 4Global MR Applications & Workflow, GE Healthcare, Hino, Tokyo, Japan, 5Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States, 6Global MR Applications & Workflow, GE Healthcare, Houston, TX, United States |
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Here we present a multi-slice, multi-phase, single-shot fast spin echo sequence with variable refocusing flip angle and interleaved cylindrical reference navigator for retrospective respiratory-guided image sorting for the purpose of managing motion in the context of MR-guided radiation therapy treatment planning. |
| 4258 | Computer #63 |
Beyond high resolution MPRAGE: In vivo T1-weighted imaging at 7T with 250 µm isotropic resolution using prospective motion correction |
1Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Germany, 2Leibniz Institute for Neurobiology, Magdeburg, Germany, 3Center for Behavioral Brain Sciences, Magdeburg, Germany, 4German Center for Neurodegenerative Disease, Magdeburg, Germany |
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Increasing the spatial resolution is of major importance to structural imaging as this may build bridges to optical microscopy and may lead to superior diagnostics and segmentations. Increasing the spatial resolution with sufficient SNR usually prolongs time of acquisition. This inevitably introduces more motion artifacts even with experienced subjects. However, this can be compensated by prospective motion correction. Increasing the resolution to a few hundred micrometers inherently reduces SNR such that reconstruction by sum of squares is not adequate anymore. Here we demonstrate our work on the acquisition and reconstruction of the currently highest resolution in vivo MPRAGE at 7T. |
| 4259 | Computer #64 |
Low rank and sparsity on MR-based PET motion correction using simultaneous PET/MRI: a patient study |
1Key laboratory of Particle and Radiation Imaging, Ministry of Education, Tsinghua University, Beijing, China, People's Republic of, 2Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, MA, United States, 3UCSF/UC Berkeley Bioengineering Graduate Group, University of California Berkeley, Berkeley, CA, United States |
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In this work, we exploited the low-rank and sparse properties of dynamic MRI data to accelerate the MR acquisition and assessed its impact on MR-based PET respiratory motion using a PET/MR oncologic patient study. PET/MR motion correction workflow was accomplished, and good performance of partially sampled MR based motion correction attests the possibility of faster PET/MR data acquisition and better lesion estimation. |
| 4260 | Computer #65 |
High Efficiency Coronary MRA: Beyond the Quiescent Period |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Department of Computer and Information Science, University of Pennsylvania, Philadelphia, PA, United States, 3Bioengineering, University of California, Los Angeles, CA, United States |
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Current motion compensation strategies for whole-heart coronary MRA only accept data acquired during specific motion phases, thus significantly reduce the imaging efficiency. In this work, we developed a reconstruction framework based on 4D coronary MRA that allowed one to increase the cardiac gating efficiency by accepting cardiac phases beyond the quiescent period, while minimizing the associated cardiac motion artifacts through non-rigid motion correction. Preliminary results from healthy subjects showed that the proposed method significantly improved the imaging efficiency, aSNR, and coronary sharpness compared with images reconstructed from the quiescent period. |
| 4261 | Computer #66 |
Motion Tracking using Nonlinear Gradient Fields: Experimental Verification and Oblique Slices |
1Diagnostic Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States, 2Neurosurgery, Yale University, New Haven, CT, United States |
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Motion navigation using nonlinear gradient fields is demonstrated experimentally. The method makes use of the simultaneous multi-dimensional encoding capabilities of nonlinear gradient fields. A two-dimensional navigator image is obtained from a single-echo encoded using a nonlinear gradient field and multiple receiver coils. Without exceeding the maximum field generated by the linear gradient fields of a 3T scanner inside a 20cm isotropic field-of-view, the navigator can be acquired in under one millisecond, including its rewinder. The method can track both translational and rotational in-plane rigid body motion, as demonstrated in phantom experiments. Simulations show the method is applicable in oblique angles. |
| 4262 | Computer #67 |
3D Stack-of-Stars Dixon Fat-Only Signal for Respiratory Motion Detection |
1Biomedical Physics, UCLA, Los Angeles, CA, United States, 2Radiological Sciences, UCLA, Los Angeles, CA, United States, 3Neurology, UCLA, Los Angeles, CA, United States |
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Respiratory motion is one of the biggest confounders of liver DCE-MRI. There are methods that use a 3D radial self-gated signal (SGS) to compensate for respiratory motion. However, SGS includes both respiratory motion and contrast uptake in DCE-MRI, and it is not trivial to perfectly separate the two from SGS, leading to inaccuracies of respiratory motion. In this work, we propose a method to extract the respiratory motion only from SGS using golden angle radial acquisition with two-point Dixon separation. The proposed method utilizes the fact the fat-only SGS does not include contrast uptake while including the same respiratory motion. |
| 4263 | Computer #68 |
Navigator-Free Motion Correction for Cartesian FSE |
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, China, People's Republic of, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China, People's Republic of |
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A navigator-free motion correction method for Cartesian FSE is proposed for intermittent motion compensation. It first divides all shots into several motion-free groups, then estimates and corrects inter-group motion. In vivo imaging results show that this approach has decent performance in dealing with intermittent motion problems. Though only demonstrated with Cartesian acquisition, it is also applicable for non-Cartesian acquisitions, such as spiral and radial acquisitions. |
| 4264 | Computer #69 |
Phantom pose detection with spherical navigator echoes for calibration of optical tracking systems in MRI |
1Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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In this work, we present a new k-space based approach for position and rotation detection to improve calibration of optical tracking systems used for prospective motion correction in MRI. 3D radial acquisition was employed to detect motion of a custom built phantom. The integrated method was tested for different motion types and showed a high precision along with a good robustness for rotation detection. |
| 4265 | Computer #70 |
Respiratory Motion Corrected 3D Patch based Reconstruction of Under-sampled Data for Liver 4D DCE-MRI |
1College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China, People's Republic of, 2Department of Radiology, Weill Cornell Medical College, New York, NY, United States, 3Department of Biomedical Engineering, Cornell University, Ithaca, NY, United States |
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Liver dynamic contrast enhanced MRI (DCE-MRI) requires high spatial and temporal resolution such that all relevant enhancement phases are clearly visualized. Image quality is compromised when breathing occurs during the acquisition. This abstract presents a novel 4D respiratory Motion corrected Patch based Reconstruction of Under-sampled Data (M-PROUD) which uses 3D patch based local dictionaries for sparse coding and simultaneously estimates 3D nonrigid motion. Results on in vivo data demonstrated that the proposed method can significantly reduce motion blurring artifacts and preserve more details at a sub-second temporal frame rate in free breathing liver 4D DCE-MRI. |
| 4266 | Computer #71 |
Motion-Robust Abdominal DCE-MRI Using Respiratory-Gated Golden-Angle Radial Sparse Parallel MRI |
1Siemens Healthcare GmbH, Erlangen, Germany, 2Medical Imaging Technologies, Siemens Healthcare, Princeton, NJ, United States, 3Radiology, New York University School of Medicine, New York City, NY, United States, 4Klinik für Radiologie und Nuklearmedizin, Universitätsspital Basel, Basel, Switzerland |
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Although the radial sampling scheme of GRASP DCE-MRI leads to inherent motion robustness, strong respiration can still impair the image quality of free-breathing abdominal examinations. We propose to combine GRASP with respiratory gating to minimize motion artifacts within and between temporal frames, without prolonging the reconstruction time and maintaining a high spatio-temporal resolution. A validation in 10 clinical patients confirmed the improved sharpness of the gated reconstruction. |
| 4267 | Computer #72 |
Investigating the temporal stability of phase offsets at 7T for field mapping and multi-channel phase combination. |
1High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria |
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A common assumption for phase combination and dynamic distortion correction is that phase offsets ($$$Ф_0$$$), i.e. the phase of coil sensitivities, are temporally stable. We investigate the validity of this assumption at 7T for long measurements (40min) and large head rotations (up to 12°) made with multi-channel coils. We show that changes in separate-channel $$$Ф_{0,ch}$$$ have little effect on the combined phase images (unwarping errors of 0.2 voxel, reduction in phase matching quality by 2%). We thus conclude that the assumption of $$$Ф_0$$$ temporal stability holds and methods based on this assumption should work at 7T with substantial motion. |
| Exhibition Hall | Thursday, May 12, 2016: 11:30 - 12:30 |
| 4268 | Computer #1 |
Off-Resonance Map Extrapolation Using Image Inpainting |
1Imaging Research, Barrow Neurological Institute, Phoenix, AZ, United States |
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An inpainting technique using the fast marching method was used to implement a fast, robust algorithm for extrapolating $$$\Delta f_0$$$ map data into low signal areas. |
| 4269 | Computer #2 |
Measuring Magnetic Field Inhomogeneity From Spatial Distortion of Echo Planar Images |
1Radiology, University of Kentucky, Lexington, KY, United States, 2Radiation Medicine, University of Kentucky, Lexington, KY, United States |
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We developed an imaging and analysis method to use the spatial distortion in echo planar images to estimate the magnetic field inhomogeneity. The method requires the acquisition of two images from an unmodified echo planar sequence with the direction of the phase encode reversed between the two. After combining the images appropriately an undistorted and a displacement image are produced. The displacement image is a map of the local magnetic field inhomogeneity. |
| 4270 | Computer #3 |
Real time shimming over multiple regions across the DTI volume with motion correction using a multislab navigated DTI sequence |
1Human Biology,MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa, 2Massachusetts General Hospital, Charlestown, MA, United States |
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Most DTI acquisitions are based on 2D multislice EPI sequences. The spatial distribution of the field inhomogeneity may differ from region to region within the DTI volume. While the scanner and traditional prospective shimming methods shim over the whole volume, this may not be optimal for DTI. Further, changes in the shim in different regions across DTI volume in the presence of subject motion are yet to be explored. In this work, we introduce a technique to measure and correct the changes in the static field from region to region and for different sized regions across the DTI volume |
| 4271 | Computer #4 |
Multiband DREAM: Multi-Slice B1+ Mapping in a Single Shot |
1Philips Research, Hamburg, Germany, 2Philips Healthcare, Best, Netherlands, 3Radiology, LUMC, Leiden, Netherlands |
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Simultaneous multi-slice imaging has been employed for the DREAM B1+ mapping approach, allowing a multi-slice B1+ map to be acquired in a fraction of a second. Basic feasibility has been shown in experiments on phantoms and in vivo using a clinical 3T MRI system. The presented approach potentially allows free-breathing multi-slice B1+ mapping, freezing respiratory motion in a short single shot acquisition window. |
| 4272 | Computer #5 |
Signal-domain optimization metrics for MPRAGE RF pulse design in parallel transmission at 7 Tesla |
1Neurospin, CEA/DSV/I2BM, Gif-sur-Yvette, France, 2Siemens Healthcare, Saint-Denis, France, 3IRFU, CEA/DSM, Gif-sur-Yvette, France |
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The standard approach to design radiofrequency pulses in MRI is to minimize the deviation of the flip angle from a target value. An alternative approach is proposed here for the MPRAGE sequence which uses the signal as a surrogate of the flip angle in the optimization of the excitation and inversion pulses. The results obtained in simulation and in the brain in vivo on a parallel transmission enabled 7T scanner show two possible applications of the method: an improvement in image quality or a significant reduction of the SAR at equivalent image quality. |
| 4273 | Computer #6 |
Spiral trajectories for 2D parallel excitation of limited slice profiles |
1Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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In this study, the feasibility of 2D spiral-encoded parallel excitation of limited slice profiles was investigated. The imaging experiments were performed in phantoms on a 3T MRI system with 8 RF channels for transmission and compared to 2D parallel excitation using EPI encoding. The resulting profiles revealed that 2D spiral-encoded parallel excitation is more robust against B1 deviations compared to EPI. |
| 4274 | Computer #7 |
Transmit SENSE on a whole-body 10.5 Tesla system using 16 RF channels: initial results |
1CMRR, Radiology, University of Minnesota, Minneapolis, MN, United States |
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Increased signal to noise ratio and tissue contrast are strong incentive for pushing toward higher magnetic fields. However, as the magnetic field increases, transmit B1 fields become more and more non-uniform, leading to spatially varying contrast and local signal dropouts. This problem can be addressed with parallel RF transmission (pTx). We have recently made operational the first 10.5 Tesla whole body MRI scanner which holds promise for a wide range of biomedical applications. In this study, we assessed the performance of the installed 16-channel pTx system by designing 2D Transmit SENSE pulses. Our results suggest that high fidelity excitation patterns can be attained after correction of system imperfections. |
| 4275 | Computer #8 |
Optimization of the kT-points placement under explicit SAR and power constraints in the large flip angle regime |
1Neurospin, CEA/DSV/I2BM, Gif-sur-Yvette, France, 2IRFU, CEA/DSM, Gif-sur-Yvette, France |
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The kT-points parametrization is a powerful technique to mitigate the RF inhomogeneity at ultra-high field which can also be used to achieve homogeneous non-selective inversion profiles with less SAR than adiabatic RF pulses. The large flip angle regime thus is an interesting domain of application of the kT-points technique. However, to fully exploit it, it is necessary to optimize the placement of the kT-points in k-space. In this work, the simultaneous optimization of the RF and k-space trajectory coefficients is proposed and validated, whereby SAR and power constraints are handled explicitly. |
| 4276 | Computer #9 |
Frequency shimming with local excitation coils improves fat suppression in breast MRI at 7 T |
1Radiology, UMC Utrecht, Utrecht, Netherlands |
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Using multiple local excitation coils for different parts of the body, such as bilateral breast coils, opens up the possibility to perform frequency shimming: using multiple carrier frequencies to excite the different body parts without gradient based localization. In this work we demonstrate frequency shimming to improve fat suppressed breast MRI at 7 T. |
| 4277 | Computer #10 |
A parallel transmit VERSE RF pulse design method using dynamic field monitoring |
1Institute of Biomedical Engineering, ETH Zurich, Zurich, Switzerland, 2Kings Collage London, London, United Kingdom |
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Variable-rate selective excitation (VERSE) is a powerful method to control RF power and SAR that bounds to a key condition as retaining the RF-to-gradient amplitude ratio at each sample that preserves the rotational behavior of on-resonance spins (1). The maintenance of VERSE condition strictly depends on the fidelity of the local gradient fields implying that any deviation from the nominal VERSE’d gradients will modulate the spin rotations similar to off-resonances ultimately resulting excitation errors and the RF pulse to converge to a significantly different peak RF power. |
| 4278 | Computer #11 |
3D volumetric parallel excitation at 9.4T using the trajectory container concept |
1Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 2Institute of Biomedical Engineering, University and ETH, Zürich, Switzerland |
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This work presents experimental results of 3D volumetric parallel excitation at a 9.4T human whole-body MRI scanner. The approach and concept of a “trajectory container” is adopted to match practical considerations. The “trajectory container” is used to shape the k space trajectory and restrict it to a limited traversing area in the k space and therefore to constrain the pulse duration. A simplified and direct way of the definition of the “trajectory container” is proposed and verified with promising experimental results. |
| 4279 | Computer #12 |
Distortions during excitation and acquisition in zoomed DWI combined with parallel transmission |
1Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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In this work, we discuss off-resonance effects observed in zoomed DWI combined with 2D pulses based on EPI trajectories. Our main focus is placed on the use of parallel excitation (PEX) for shortening 2D pulses and further minimizing the distortion. Experimental data were obtained using a 3T MRI system with an 8-channel TxArray extension and analyzed in detail. We conclude that the use of PEX improves the matching between excitation and acquisition in zoomed EPI applications. |
| 4280 | Computer #13 |
Optimisation of Post-processing Correction of Transmit Field Inhomogeneity in R1 Maps by Relaxometry Modelling |
1Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom, 2Birkbeck/UCL Centre for Neuroimaging, London, United Kingdom, 3Spinal Cord Injury Center Balgrist, University Hospital Zurich, Zurich, Switzerland, 4Department of Psychology, Carnegie Mellon University, Pittsburgh, PA, United States, 5Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany |
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Unified segmentation based correction of R1 brain maps for RF transmit field inhomogeneities (UNICORT) has previously been shown to reduce bias in R1 maps caused by inhomogeneity in the RF transmit field (B1+). This approach simultaneously estimates the B1+ inhomogeneities and R1 values from the uncorrected R1 maps without the need for additional B1+ calibration data. It employs a probabilistic framework that incorporates a physically informed generative model of smooth transmit field inhomogeneities and their multiplicative effect on R1 estimates. However, different systems may require different priors, depending on the particular transmit coil used. Here we show that these parameters can be estimated using a linear relaxometry model framework, without the need to acquire B1+ mapping data. |
| 4281 | Computer #14 |
Single point based techniques for rapid and robust gradient measurement |
1Department of Radiology, University of Wisconsin, Madison, WI, United States, 2Department of Electrical and Computer Engineering, University of Wisconsin, Madison, WI, United States |
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Accurate knowledge of the k-space trajectory is critical for artifact-free MR imaging, particularly in non-Cartesian imaging. In this study we propose a new gradient measurement technique based on single point imaging (SPI), which allows simple, rapid, and robust measurement of k-space trajectory. In the proposed technique, the zoom-in/out effect of SPI is used for k-space trajectory measurement. First, 1D SPI data are acquired from a targeted gradient in each axis, and then relative FOV scaling factors between encoding times are found, which represents relative k-space position. Improvements in image quality are demonstrated for UTE, spiral, and ramp-sampled IDEAL imaging. |
| 4282 | Computer #15 |
Multi-slice spiral imaging trajectory mapping using high density 25-channel field probe array |
1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan |
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We use a dense 2D field probe array with 24 probes moving over a 3D volume to estimate magnetic field distribution dynamically and demonstrate that trajectory calibration is slice-dependent. The image reconstructed using measured dynamic magnetic field information 7 cm away shows similar l2 norm error as the image reconstructed without any dynamic magnetic field information. |
| 4283 | Computer #16 |
Linear Gradient Characterization Using A Rapid Thin-slice Measurement |
1Imaging Research, Barrow Neurological Institute, Phoenix, AZ, United States |
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Gradient impulse response functions can predict gradient behavior in the presence of eddy currents and other sources of error. This work presents a rapid method for generating the 0th and 1st order gradient impulse response functions using existing software measurement techniques. The proposed method is applied to spiral imaging but could be similarly applied to EPI, projection reconstruction, or any other imaging sequence. |
| 4284 | Computer #17 |
Chemical Shift based Fat-Water Separation using a Variational Approach for B0-field Correction |
1Institute of Medical Engineering, Graz University of Technology, Graz, Austria, 2Institute of Mathematics and Scientific Computing, University of Graz, Graz, Austria, 3Institute of Molecular Biosciences, University of Graz, Graz, Austria, 4BioTechMed Graz, Graz, Austria |
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In this work we present an approach for chemical shift based fat/water-separation using variational methods for the estimation of the underlying B0-field inhomogeneity. We show that the fat/water-problem can be solved by the application of total-generalized-variation (TGV) regularization on the underlying B0-field to enforce piecewise smoothness. With this approach we are able to model huge B0-deviations as well as discontinuities in the B0-field at tissue boundaries with different susceptibility parallel to the main-field. This is shown on different datasets, including two of the ISMRM fat/water-challenge of 2012. |
| 4285 | Computer #18 |
Reduction of Ghosting Due to Respiration Induced B0 Variation in Double Echo Steady State (DESS) Imaging in the Breast with a DC Navigator and Image Entropy Metric |
1Radiology, Stanford University, Stanford, CA, United States, 2Electrical Engineering, Stanford University, Stanford, CA, United States |
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The double echo steady state (DESS) acquisition has the potential to provide high-resolution and distortion-free T2 and diffusion-weighted images in the breast. Initial investigations of DESS in the breast have been limited by the presence of ghosting artifacts. Respiratory-induced B0 variation is one source of these artifacts. A method utilizing an in-vivo time-varying off-resonance estimate along with an image entropy metric to assess the level of artifact is described and investigated for correction of ghosting due to respiration-induced B0 variation in DESS in the breast. |
| 4286 | Computer #19 |
Gradient Pre-Emphasis Correction for First-order Concomitant Field on Head-only Asymmetric Gradient MRI System |
1Radiology, Mayo Clinic, Rochester, MN, United States, 2GE Global Research, Niskayuna, NY, United States, 3GE Healthcare, Milwaukee, WI, United States |
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Based on Maxwell’s equation, the spatial encoding gradient fields must be accompanied by spatially-varying higher-order concomitant fields. Different from conventional gradient systems whose concomitant fields contain second-order and higher spatial dependence, some MRI platforms employ asymmetric gradient systems, and their concomitant fields also include zero- and first-order terms. The first-order terms cause artifacts including image blurring and ghosting in spiral acquisition and echo shifting in EPI. Here, an efficient gradient pre-emphasis scheme suitable for real-time implementation is demonstrated to simultaneously correct all the first-order concomitant fields with a real-time implementation on gradient firmware typically used for eddy current compensation. |
| 4287 | Computer #20 |
Gradient Unwarping: Reverse Engineering the Warpfield with Spherical Harmonics |
1Neurology, Buffalo Neuroimaging Analysis Center, State University of New York at Buffalo, Buffalo, NY, United States, 2Molecular and Translational Imaging, Clinical Translational Research Center, Buffalo, NY, United States |
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Gradient “unwarping” is the removal of image distortions caused by non-linearity of the imaging gradient fields. Exasperated by increasing distance from isocenter, the unwarping process is applied to every image by the manufacturer and generally is a “black-box” process occurring near the end of the image processing pipeline. This is problematic for researchers who source their data from a more primitive step, e.g. from raw k-space, since this data is generally “warped”. Presented here is a method to reverse engineer the spherical harmonic coefficients that describe the warp field and are used by the vendor’s black-box process, allowing the researcher to perform the gradient unwarping off-line as a post-processing step. |
| 4288 | Computer #21 |
Rapid whole body B1 mapping using continuously moving table imaging at 3 Tesla |
1Department of Radiology, Vanderbilt University, Nashville, TN, United States |
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In this abstract, we present an approach for rapid mapping of the whole body B1 field at 3 Tesla. We use a combination of dual interleaved TR B1 mapping with continuously moving table imaging to measure the B1 field in the whole body in 90 seconds. Considerable variation is observed in the B1 distribution in different sections of the body. This measurement will serve as the basis for dynamic B1 field shimming with the moving table for whole body imaging in future work. |
| 4289 | Computer #22 |
Automatic Gradient Predistortion Applied to Clinical 2D-UTE |
1Institute of Image Science, Vanderbilt University, Nashville, TN, United States, 2Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 3Electrical Engineering, Vanderbilt University, Nashville, TN, United States, 4Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States |
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Transient gradient waveform errors can degrade MRI quality. This work presents an automatic implementation of gradient waveform predistortion, which has been applied to half-pulse excited 2D-ultrashort echo time imaging. The predistortion method reliably improves image quality and quantification of ultrashort T2 species by reducing out-of-slice signal that contaminates half-pulse excited images. |
| 4290 | Computer #23 |
Assessment of geometric distortion in six clinical scanners using a 3D-Printed Grid Phantom |
1Clinical Physics, Barts Health NHS Trust, City of London, United Kingdom |
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Major hardware-related geometric distortions in MRI arise from gradient field non-linearity and static field inhomogeneity. For an accurate mapping of geometrical distortion in 3D, the number of control points must be sufficiently large to provide a comprehensive mapping of the spatial variation of distortion and the positional accuracy of these control points must be ensured. In this study, the spatial accuracy of coordinates in 3D space is assessed across six clinical MRI scanners at both 1.5T and 3T field strengths using a previously reported 3D-printed grid phantom. This is a cost-effective approach to determine the spatial accuracy of control points. |
| 4291 | Computer #24 |
Characterising and Modelling Susceptibility Artifacts in the Mouse Brain at 9.4 T |
1Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 2UCL Centre for Advanced Biomedical Imaging, Division of Medicine, London, United Kingdom, 3UCL Centre for Medical Imaging Computing, London, United Kingdom |
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Susceptibility artifacts hamper gradient-echo MRI of the mouse brain at 9.4 Tesla. Here, we characterised and modelled magnetic field maps aiming to improve preclinical mouse MRI. To characterise field perturbations, we measured and coregistered field maps in 7 mice to create a group-average field map. Next, a Fourier forward model was used to simulate a field map based on a susceptibility distribution constructed from the group-average magnitude image. The measured and modelled field maps showed similar qualitative field patterns, especially around the aural air cavities, but had quantitative differences. Work is ongoing to improve the accuracy of the model. |
| Exhibition Hall | Thursday, May 12, 2016: 11:30 - 12:30 |
| 4292 | Computer #25 |
Zero Echo Time imaging of ocular tumours at 7T |
1Leiden University Medical Centre, Leiden, Netherlands, 2Philips Research Laboratories, Hamburg, Germany |
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MRI is becoming an increasingly valuable non-invasive tool in ocular tumour assessment and treatment planning. ophthalmology. High resolution images acquired at high field provide multi-dimensional information on tumour size. However, image quality is often compromised by eye motion which is often triggered by gradient noise In the present work the use of magnetization prepared 3D Zero Echo Time imaging (ZTE) is proposed, enabling for almost silent volumetric scanning at isotropic resolution. An initial validation showing the potential of the ZTE approach at 7T for is shown in volunteers and tumour patients. |
| 4293 | Computer #26 |
In-vivo detection of oscillatory magnetic field with an oscillatory-selective detection (OSD) |
1Center for MRI Research, Peking University, Beijing, China, People's Republic of, 2GE Healthcare, MR Research China, Beijing, China, People's Republic of |
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In-vivo detection of oscillatory magnetic field may lead to fundamental development of functional MR imaging. The recently developed spin-lock oscillatory excitation (SLOE) method exhibited sub-nanotesla level of sensitivity. However its application in vivo is troubled by main field inhomogeneity. In this work, an oscillatory-selective detection (OSD) is proposed to overcome this limitation and hence to improve sensitivity of in-vivo detection of oscillatory magnetic field. OSD has also been verified as a viable tool in mapping transcranial alternating current. |
| 4294 | Computer #27 |
Simultaneous Spin Echo and Gradient Echo Imaging with Controlled Aliasing and Parallel Imaging Reconstruction |
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China, People's Republic of, 3Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong SAR, China, People's Republic of |
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We propose a method to simultaneously acquire spin echo and gradient echo and form two images with distinct contrasts. The spin echo and gradient echo are created by phase-cycled RF pulses, so that they are shifted from each other in image space. In reconstruction, coil sensitivity information can be used to separate them. This study demonstrates the feasibility of extracting multiple echo components using controlled aliasing and parallel imaging reconstruction. |
| 4295 | Computer #28 |
Single-shot T2 mapping through overlapping-echo detachment planar imaging (OLED) sequence |
1Department of Communication Engineering, Xiamen University, Xiamen, China, People's Republic of, 2Department of Imaging Sciences, University of Rochester, ROCHESTER, NY, United States, 3Department of Electronics Science, Xiamen University, Xiamen, China, People's Republic of |
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Magnetic Resonance parameters mapping can provide useful quantitative information for characterization of tissue properties. However, the long acquisition time usually hinder the real-time MR parameter mapping. In this abstract, a novel single-shot T2 mapping method was proposed based on spin-echo EPI method. Two overlapping echo signals with the different T2 weighting were obtained simultaneously. A detachment algorithm based on joint sparsity constraint was proposed to separate the two echo signals. The robustness and efficiency of the sequence were demonstrated through phantom experiments. The reliable T2 mapping can be obtained in the order of milliseconds. |
| 4296 | Computer #29 |
Simultaneous Quantification of T1, T2 and Diffusion with Diffusion-weighted drive-equilibrium prepared Magnetic Resonance Fingerprinting |
1Department of Biomedical Engineering, Case Western Reserve University, Clevleand, OH, United States, 2Department of Radiology, Case Western Reserve University, Clevleand, OH, United States |
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The purpose of this study is to develop a method for simultaneous quantification of T1, T2, and diffusion within the MR Fingerprinting (MRF) framework. Multiple diffusion-weighted driven-equilibrium modules are inserted into the MRF-FISP acquisition in this study. The results from the prostate show the promising ability of this combination of MRF-FISP and diffusion preparation modules to quantify relaxation parameters along with diffusion in one scan. |
| 4297 | Computer #30 |
Multi-shot Magnetic Resonance Fingerprinting using Saturation Recovery Preparation Pulse |
1Medical Imaging Technologies, Siemens Healthcare, Princeton, NJ, United States, 2Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States |
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In MRF, a single image is reconstructed from data collected from each short TR due to the non-repeatable magnetization history. The highly-undersampled single-shot imaging leads to high levels of noise and artifacts. In this study, an SR preparation module was introduced to MRF, enabling multi-shot MRF without a waiting time for magnetization recovery. The SR prepared multi-shot MRF can achieve similar or even better accuracy than the original single-shot IR prepared MRF with the same amount of data collected. |
| 4298 | Computer #31 |
Optimizing MRI contrast with optimal control theory |
1CREATIS, Université de Lyon ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Claude Bernard Lyon 1, Lyon, France, 2Department of Chemistry, Technische Universität München, Munich, Germany, 3Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR 5209 CNRS-Université de Bourgogne, Dijon, France |
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Magnetic Resonance Imaging (MRI) uses the difference in tissue relaxation times to create contrast. Various image weightings can be obtained by tuning acquisition parameters which are usually empirically defined. In this article, optimal control theory is used to design excitation pulses that produce the optimal contrast between given tissues. The designed pulses are tested on numerical phantoms with and without magnetic field inhomogeneities and for the first time in vitro on a small-animal MRI. The reasonable match between simulation and real experiments is promising for the development of such pulses in further in vivo applications. |
| 4299 | Computer #32 |
Correction of Phase Offset Induced From Eddy Current in MR Phase Contrast Cine Flow Measurement of Cerebrospinal Fluid in the Cervical Spine |
1Radiology, University of Louisville, Louisville, KY, United States, 2Neurosurgery, University of Louisville, Louisville, KY, United States |
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The phase offset in the phase contrast MR flow imaging was corrected using an image-based method in order to account for the spatially inhomogeneous and subject-dependent phase offset. The phase shift on the flow region was estimated iteratively from the phase shift of the stationary tissue using the low spatial distribution of the phase offset. This phase offset correction method with an automated segmentation and iterative estimation of the phase offset allowed us to study the cerebrospinal fluid flow in the spinal subarachnoid space of ten healthy and ten spinal cord injury participants reliably without elaborate manual effort. |
| 4300 | Computer #33 |
MR artifacts removal using sparse + low rank decomposition of annihilating filter based Hankel matrix |
1Dept. of Bio and Brain Engineering, KAIST, Daejeon, Korea, Republic of |
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In this paper, we propose a sparse and low-rank decomposition of annihilating filter-based Hankel matrix for removing MR artifacts such as motion, RF noises, or herringbone artifacts. Based on the observation that some MR artifacts are originated from k-space outliers, we employ a recently proposed image modeling method using annihilating filter-based low-rank Hankel matrix approach (ALOHA) to decompose the sparse outliers from the low-rank component. The proposed approach can be applied even for static images, because the k-space low rank component comes from the intrinsic image properties. We demonstrate that the proposed algorithm clearly removes several types of artifacts such as impulse noises, motion artifacts, and herringbone artifacts. |
| 4301 | Computer #34 |
Gradient Nonlinearity and B0-induced Distortion Corrections of Prospective Motion Correction Data at 7T MRI |
1Department of Biomedical Magnetic Resonance, Otto-von-Guericke University Magdeburg, Magderburg, Germany |
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Patient motion during an MRI of the brain can result in non-diagnostic image quality. Even with perfect prospective motion (PMC) tracking and correction, the varying coil sensitivity, gradient non-linearity, and B0 field shift can cause significant artifacts that cannot be corrected prospectively. Recently, a model-based MR image reconstruction via iterative solver was employed to minimize the sensitivity misalignment due to physiological movement. In this study, we extended the mentioned model by gradient-warped and B0-induced distortion corrections to reconstruct the PMC MR data. The result shows the improvement that is remarkably reduced artifacts after a few iterations of the proposed technique. |
| 4302 | Computer #35 |
Referenceless high order EPI calibration based on multiplexed SENSE |
1Radiology Department, University of Cambridge, Cambridge, United Kingdom, 2GE healthcare MR Research China, Beijing, China, People's Republic of, 3GE heathcare China, Beijing, China, People's Republic of |
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Usually aper-volume or even per-slice basis reference scan is usually needed for correcting the phase inconsistency between odd and even shots attributed to eddy current in EPI. The phase correction is usually first order. In this work, the concept of multiplxed SENSE (MUSE) is extended for EPI N/2 ghost calibration. |
| 4303 | Computer #36 |
Improving functional imaging of the fetal brain using constrained image-based shimming to suppress maternal fat |
1Biomedical Engineering, King's College London, London, United Kingdom, 2Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal, 3Perinatal Imaging and Health, King's College London, London, United Kingdom, 4Centre for the Developing Brain, King's College London, London, United Kingdom |
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Effective suppression of maternal fat is critical for functional imaging of the fetal brain with echo planar imaging (EPI). Localized image-based shimming (IBS) for the fetal brain is required but can provoke high field variation in maternal adipose regions causing fat suppression to fail. We have addressed this issue by using IBS of the fetal brain with linear constraints across maternal fat regions and optimization of saturation pulse frequency offset. The results showed that is possible to obtain more complete fat supression when combining an optimized pulse offset with a constrained shimming approach without compromising fetal brain shim. |
| 4304 | Computer #37 |
Sparse Parameter Global Signal Correction for Resting State fMRI Analysis |
1Department of Biomedical Engineering, Columbia University, New York, NY, United States, 2Coulter Department of Biomedical Engineering, Georgia Tech and Emory University, Atlanta, Georgia |
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We describe a novel global signal removal method, sparse parameter global signal regression (SP-GSR), for fMRI data preprocessing. We assume the global signal to be low-rank and the remaining signal can be decomposed into orthogonal regressors with spatially sparse parameters. We demonstrated by simulation that SP-GSR can remove global signal and recovery true correlations without introducing anti-correlations. Application of this method to experimental data led to a more prominent and focused default mode network with isolated negative correlations. |
| 4305 | Computer #38 |
Data Acquisition Strategies for Reducing Eddy-Current and Transient Oscillation Artifacts in Balanced Steady-State Free Precession |
1Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea, Republic of, 2Department of Radiology, Seoul National University College of Medicine, Seoul, Korea, Republic of |
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The quality of balanced steady-state free precession is vulnerable to eddy-currents and transient oscillations. However, the conventional centric phase-encoding (PE) scheme makes these artifacts severe, thus needs additional compensation strategies. In this study, we propose an improved PE scheme where k-space is encoded from center to periphery in a group-wise manner (PE-grouping). This reduces related artifacts by preventing big jumps in k-space along PE direction. Also proposed were various averaging strategies that could further eliminate the residual artifacts by averaging two full images acquired not only with the PE-grouping, but also with the conventional centric and pairing schemes. |
| 4306 | Computer #39 |
An effective way of overcoming TE variation in single-refocusing spatiotemporal-encoding imaging. |
1Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Korea, Republic of, 2Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of |
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RASER(Rapid Acquisition by Sequential Excitation and Refocusing) sequence acquires all the echoes with same TE by using two refocusing pulses [1], whereas other spatiotemporal-encoding(SPEN) techniques using a single-refocusing pulse offers a shorter effective TE than RASER but with varying TE, thereby causing signal variation in the SPEN dimension [2]. Here, we propose an effective way of overcoming this problem of TE variation in single-refocusing SPEN imaging. |
| 4307 | Computer #40 |
Improved gradient warping correction for large field-of-view imaging and application to radiation therapy planning |
1Mayo Clinic, Rochester, MN, United States, 2Radiation Oncology, Mayo Clinic, Rochester, MN, United States, 3MD Anderson, Houston, TX, United States, 4GE Global Research, Niskayuna, NY, United States |
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Radiation therapy, especially proton beam therapy requires exacting spatial accuracy to deliver a sterilizing dose of ionizing radiation to the target volume with confidence. The superior soft tissue contrast afforded by MRI vs. CT has increased interest in using MRI for treatment planning. However, gradient non-linearities reduce the spatial accuracy of MRI. We have developed a fiducial phantom based calibration procedure to map these gradient nonlinearities on a system-specific basis and generate up to 9th order spherical harmonic coefficients for correction. These coefficients show improved spatial accuracy vs. standard 5th order, especially at distances >400mm from magnet and gradient isocenter. |
| 4308 | Computer #41 |
Calibration-free EPI trajectory error correction by k-space data consistency |
1Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 2Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 3Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, 4Department of Electrical Engineering, Vanderbilt University, Nashville, TN, United States |
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A method for automatic correction of EPI trajectory errors is presented. The method is an iterative parallel imaging reconstruction which uses k-space data consistency to correct image artifacts. An advantage of the method is that it requires no calibration data and allows correction of non-static errors such as those due to gradient coil heating. |
| 4309 | Computer #42 |
Measurement of magnetic susceptibility of commonly implanted metals from commercial prostheses |
1Radiology, University of Wisconsin, Madison, WI, United States, 2Florida State University, Tallahassee, FL, United States, 3St. Jude's Children's Hospital, Memphis, TN, United States, 4Medical Physics, University of Wisconsin, Madison, WI, United States |
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Despite important recent development, further progress of MR imaging around metallic prostheses is dependent on the ability to model the field perturbations surrounding the prostheses. These calculations require knowledge of the magnetic susceptibility of the metal which is not reported by the manufacturers. The purpose of this work was to estimate the magnetic susceptibility of commonly implanted metal alloys by measuring the magnetic moment across a range of clinical field strengths (0-5 Tesla) using a SQUID (Superconducting QUantum Interference Device) magnetometer. Linearity of the susceptibility across field strengths was also assessed. |
| 4310 | Computer #43 |
Phase drift effect correction for MR Thermometry using magnetic field monitoring |
1Bio-medical engineering, Kyung Hee University, Yogin, Korea, Republic of |
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We propose a method to correct phase drift artifact from MR thermometry measurements with the use of Magnetic field monitoring (MFM). Field variations are measured with an array of MFM probes and correction maps are computed from the frequency shifts of FID signals. This method allows to have better resolution and can be used with any MR thermometry pulse sequence. |
| 4311 | Computer #44 |
Reference-free Nyquist ghost removal in single-shot SPEN MRI using phase-corrected partial Fourier reconstruction |
1Center for Brain Imaging Science and Technology, Zhejiang University, Hangzhou, China, People's Republic of, 2MR Collaboration Northeast Asia, Siemens Healthcare, Shanghai, China, People's Republic of, 3Department of Electronic Science, Xiamen University, Xiamen, China, People's Republic of, 4Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, China, People's Republic of |
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Single-shot SPEN MRI is a technique capable of retaining the time efficiency of single-shot EPI but with significantly reduced geometric distortions. Akin to EPI, the phase inconsistency between even and odd echoes also result in Nyquist ghosts in SPEN images. This work is to present a scheme with more reliable performance than the previously reported Nyquist ghost correction method. Experimental results of human brains and in vivo rats show that the proposed method can remove ghosts without introducing blurring, and unwarping procedures can be conducted on the ghost-corrected data for further distortion correction. |
| 4312 | Computer #45 |
Comparison of methods for choosing radial spoke directions in 3D UTE |
1Aix Marseille Université, MARSEILLE, France |
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Several algorithms for choosing the radial spoke directions were evaluated for use in 3D UTE imaging. It was observed that methods that produce a highly regular set of directions result in higher aliasing than those that are more irregular. |
| 4313 | Computer #46 |
Flow-induced artifacts in two-point Dixon MRI: Incidence, severity and potential diagnostic pitfalls. |
1Radiology, University of Wisconsin Madison, Madison, WI, United States, 2Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 3Medical Physics, University of Wisconsin Madison, Madison, WI, United States |
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Chemical shift based two-point “Dixon” MRI with bipolar readout gradients may produce flow induced fat-water misallocation artifacts. These artifacts have the potential to mimic intravascular thrombus. We reviewed 100 cases of two-point body MRI exams to characterize the incidence, location and severity of these artifacts. Artifacts appeared in 46% of the cases, with severe artifacts in 20% and mild artifacts in 26% of the patients. Given this high number of potentially thrombus-mimicking, flow-induced artifacts, radiologists should be aware of this potential pitfall when using two-point fat-water separation methods. |
| 4314 | Computer #47 |
Two-Step Generic Referenceless Phase Combination (GRPC) for accurate phase image reconstruction from multiple receiver coils |
1Radiological Physics, University of Basel Hospital, Basel, Switzerland, 2Department of Biomedical Engineering, University of Basel, Basel, Switzerland, 3Institut du Cerveau et de la Moelle épinière, Hôpital Pitié-Salpêtrière, Paris, France, 4CNRS, ICube Laboratory, FMTS, Université de Strasbourg, Strasbourg, France |
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This work presents a method to combine the signal from multiple coils in order to obtain a coherent phase image. The methods is agnostic to the acquisition protocol and the coil geometry, and does not require operator interaction. |
| 4315 | Computer #48 |
Image-based phase correction for dual-band EPI with slice-GRAPPA using point-by-point procedures in k-space |
1CiNet, NICT, Suita, Japan, 2Department of Structural BioImaging, Kumamoto University, Kumamoto, Japan |
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We proposed an Image-based phase correction for dual-band EPI with slice-GRAPPA using point-by-point procedures in k-space. The results showed the usefulness and robustness of the proposed method compared with the conventional approach. |
| Exhibition Hall | Thursday, May 12, 2016: 11:30 - 12:30 |
| 4316 | Computer #49 |
A combinatorial model approach for feature selection from multimodal MRI data |
1Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States, 2Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO, United States |
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Clinical applications of brain abnormality detection with supervised machine learning techniques are limited due to less and unbalanced sample sizes as compared to rich feature sets in patient population. We proposed a new combinatorial model approach, fs-RBFN, involving sampling from multivariate joint distribution, LASSO feature selection, RBFN cross validation, and inverse probability weighting to solve this problem. The proposed approach was validated against a ground truth phantom and further tested on a multimodal MRI dataset for cognitively impaired and non-impaired professional fighters. Our results suggest superior performance of this technique over several other out-of-the-bag feature selection algorithms. |
| 4317 | Computer #50 |
Three-dimensional lung tumour motion tracking using an advanced template matching technique: Texture Reformatted Angle Correlation (TRAC) |
1Ingham Institute for Applied Medical Research, Sydney, Australia, 2South Western Sydney Clinical School, University of New South Wales, Sydney, Australia, 3Department of Medical Physics, Cancer Therapy Centre, Liverpool Hospital, Sydney, Australia, 4Centre for Medical Radiation Physics (CMPR), University of Wollongong, Sydney, Australia |
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Real-time lung tumour tracking and motion analysis is important in MRI-based radiotherapy planning to inform treatment margins and to permit accurate delivery for developing MR-Linac technology. This work describes a template matching approach to provide 3D motion assessment of lung tumours from real-time 2D images. Compared to previous work the TRAC technique utilises a multi-angled correlation analysis of the target region to correctly identify the tumour position. Results in both a moving phantom and in lung cancer patients show that the technique is feasible, accurate and can be easily adopted in widely used single plane cine imaging. |
| 4318 | Computer #51 |
Renal segmentation from non-contrast T1-weighted MR images |
1Bernard and Irene Schwartz Center for Biomedical Imaging, Center for Advanced Imaging Innovation and Research, Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Department of Radiology, Austin Health, Melbourne, Australia, 3Department of Endocrinology, Austin Health, Melbourne, Australia, 4Florey Neuroscience Institute, Melbourne, Australia, 5The University of Melbourne, Melbourne, Australia |
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A semi-automatic renal segmentation technique for non-contrast T1-weighted MR images was developed. Renal segmentation and volumetric analysis was tested in ten healthy volunteers and ten Type I diabetic patients. We found that this segmentation tool is fast, reliable, and requires minimal user interaction. Upon further validation, this method has clinical potential for monitoring renal status in appropriate patient populations. |
| 4319 | Computer #52 |
Exploring abnormal arch shape patterns using CMR-based hierarchical 3D shape clustering: Application to a generic imaging population of repaired coarctation of the aorta |
1Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science & Great Ormond Street Hospital for Children, London, United Kingdom |
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We present a novel method for hierarchical 3D shape clustering of aortic arch shape models segmented and reconstructed from CMR imaging data. We apply the method to a cohort of 45 patients post aortic coarctation repair in order to explore previously unknown arch shape patterns that may relate to clinical outcome. Exploring a pathologic shape population using data mining and statistical shape modeling techniques can provide novel insight for improved diagnosis and treatment strategies and can thereby assisst in clinical decision making when analysing complex cases. |
| 4320 | Computer #53 |
Direct CT conversion from a single ultra-short echo sequence |
1eHealth, CSIRO, Brisbane, Australia, 2Liverpool Cancer Therapy Centre, Liverpool, Australia, 3Siemens Healthcare Pty Ltd, Macquarie Park, Australia, 4Medical Physics, Ingham Institute, Liverpool, Australia, 5UNSW Australia, Liverpool, Australia, 6University of Wollongong, Wollongong, Australia |
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Accurate conversion of MRI into attenuation correction maps is of current interest in PET-MR and MR-only radiotherapy planning in particular, where electron density calculation is particularly demanding and usually derived from CT. MRI methods to date have usually involved building a patient atlas and/or use of multiple imaging sequences and are time intensive. We propose a new single sequence approach based on ultra-short echo time to identify tissue classes of air, bone and soft-tissue in combination with a dynamic clustering regression based model that provides a direct CT conversion which is both efficient and accurate. |
| 4321 | Computer #54 |
Non-invasive estimation of arterial input function for imaging of cerebral blood flow on a PET/MR scanner |
1Applied Science Lab, GE Healthcare, Menlo Park, CA, United States, 2Radiology Department, Stanford University, Stanford, CA, United States, 3Applied Science Lab, GE Healthcare, Zurich, Switzerland, 4Molecular Imaging Program, Stanford University, Stanford, CA, United States |
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Accurate measurement of Arterial Input Function (AIF) is essential in quantitative analysis of cerebral blood flow (CBF) using 15O-H2O PET imaging. The time-of-flight enabled Signa PET/MR scanner (GE Healthcare, Waukesha, WI, USA) provides quality PET images during the arrival of 15O-H2O tracer to the brain arteries, which can be used for carotid artery segmentation. The optimal time frame to segment these brain arteries for image-based AIF, is found by binning the PET list file every second and plotting the total number of true and scatter coincident events over time. |
| 4322 | Computer #55 |
Partial volume correction of quantitative susceptibility maps for oxygen extraction fraction measurements. |
1Monash Biomedical Imaging, Monash University, Clayton, Australia, 2Faculty of Information Technology, Monash University, Clayton, Australia, 3Lucas Center for Imaging, Department of Radiology, Stanford University, Stanford, CA, United States, 4Monash eResearch Centre, Monash University, Clayton, Australia, 5ARC Centre of Excellence for Integrative Brain Function, Melbourne, Australia |
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Partial volume effects impede the use of quantitative susceptibility maps for assessing small veins. Oxygen extraction fraction measures are particularly sensitive to these effects. We propose a geometric technique for calculating partial volume from binary venograms. The technique is able to calculate accurate partial volume maps, and vessel geometry, on simulated veins of sub-voxel radius. These partial volume maps are used to adjust for partial volume effects in estimating venous magnetic susceptibility. |
| 4323 | Computer #56 |
Improving Tissue Segmentation of Brain MRI through Sparsity-guided Super-resolution Imaging |
1Radiology, New York University School of Medicine, New York, NY, United States |
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Since human gray matter cortex is a relatively thin structure and has a complex folding pattern blended with white matter and cerebrospinal fluid (CSF), partial volume effect is always considered a challenging issue for precise tissue segmentation. Super-resolution (SR) is a common method that is often used in the picture world to recover a high-resolution image from low-resolution images. This study was performed to test whether a newly developed sparsity-guided SR algorithm can be adapted on standard clinical MRI images to improve brain tissue segmentation by decreasing partial volume effect. |
| 4324 | Computer #57 |
Data and cluster-extent based thresholding to analyze statistical parametric maps in the study of knee articular cartilage biochemical composition. |
1Radiology & Biomedical Imaging, UCSF, San Francisco, CA, United States |
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Voxel-based relaxometry (VBR) allows for MR relaxtion time analysis without the sometimes deletorious assumtions of traditional ROIs. However, VBR introduces potentially new analysis issues, such as noise and map heterogeneity. In this study we propose to use VBR significance thresholding in conjunction with cluster-extent based thresholding to define data-driven regions of interest (ROIs) that include the most critical information in Statistical Parametric Maps (SPM), controlling the aforesaid issues. The results suggests that the data driven voxel cluster ROIs and predefined traditional ROIs have unique, separate anatomical locations, and that the data-driven clusters perform better when correlated to osteoarthritis (OA) disease markers. |
| 4325 | Computer #58 |
Automatic organ-specific localization and quantification of fat in abdominal chemical shift encoding-based water-fat MRI: application to weight-loss in obesity |
1Department of Computer Science, TU Munich, Munich, Germany, 2Department of Radiology, TU Munich, Munich, Germany, 3Else Kröner Fresenius Center for Nutritional Medicine, TU Munich, Munich, Germany, 4ZIEL Research Center for Nutrition and Food Sciences, TU Munich, Munich, Germany, 5Philips Healthcare, Hamburg, Germany |
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The accumulation and regional distribution of abdominal adipose tissue and organ fat plays an important role in several diseases including obesity, metabolic syndrome and diabetes. The present work proposes a fully automatic method for abdominal organ segmentation and adipose tissue classification and measurement based on chemical shift encoding-based water-fat MR images. The results from the automatic method showed very good agreement with the manually created references. The developed automatic algorithm allowed the detection of regional differences in changes of adipose tissue depots in a study of 20 obese women undergoing a calorie restriction intervention. |
| 4326 | Computer #59 |
Semi-Automatic Comparison of Myocardial Tissue Injury using a Non-Rigid Registration Method in patients with non-ischemic disease |
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine, Berlin, Germany, 2Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center (ECRC), Berlin, Germany, 3Department of Cardiology and Nephrology, HELIOS Klinikum Berlin Buch, Berlin, Germany, 4Siemens Healthcare GmbH, Erlangen, Germany |
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Late Gadolinium Enhancement (LGE) is the noninvasive gold standard for focal fibrosis, parametric mapping with and without contrast-media enable detection of diffuse fibrosis. We developed a non-rigid registration method to superimpose LGE images and T1-Maps allowing for pixel-wise comparison of LGE extent and abnormal T1 times. We observed significantly larger regions of ECV, T1 native and post-contrast abnormalities than LGE positive areas. However, LGE was not always completely covered by abnormalities of any of the mentioned parameters. |
| 4327 | Computer #60 |
MRI-guided PET image denoising using a non-local means filter |
1Centre d'imagerie moléculaire de Sherbrooke, Université de Shebrooke, Sherbrooke, QC, Canada |
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Positron emission tomography (PET) images suffer from statistical noise, especially in short time frames. For applications requiring high temporal resolution, such as dynamic studies, efficient edge-preserving denoising algorithms such as the non-local means filter (NLMF) are needed. Because this filter relies on structural data, coregistered MR images were used to guide the NLMF. This novel method was compared to conventional PET-guided NLMF and proved superior in terms of increased contrast-to-background ratio and signal-to-noise ratio in a phantom model. It also increased small structure resolution in a rat model. |
| 4328 | Computer #61 |
THOMAS: Thalamus Optimized Multi-Atlas Segmentation at 3T |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Neuroradiology, Bordeaux University Hospital, Bordeaux, France, 3Radiology, University of Arizona, Tucson, AZ, United States, 4Radiology, Stanford University, Stanford, CA, United States |
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The efficacy of the Thalamus Optimized Multi-Atlas Segmentation (THOMAS) algorithm for segmentation of thalamic nuclei with white-matter-nulled MP-RAGE images is studied in 3T and 7T variants of the image contrast. 5 subjects are evaluated at both field strengths and ground truth manual delineations of nuclei are performed on the 7T images. We demonstrate that the algorithm performs as well on 3T images as on 7T within a dice coefficient of ±0.1 as evaluated against the ground truth. This indicates that THOMAS can now reach a much wider audience of interested groups. |
| 4329 | Computer #62 |
Evaluation of feature-driven clustering of dynamic contrast enhanced and oxygen enhanced MRI data to assess tumour microenvironment heterogeneity |
1Centre for Imaging Sciences, The University of Manchester, Manchester, United Kingdom, 2CRUK & EPSRC Cancer Imaging Centre in Cambridge and Manchester, Cambridge and Manchester, United Kingdom, 3Institute of Cancer Sciences, The University of Manchester, Manchester, United Kingdom, 4School of Pharmacy, The University of Manchester, Manchester, United Kingdom, 5Bioxydyn Ltd., Manchester, United Kingdom |
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DCE-MRI and OE-MRI scans were performed on 8 preclinical U87 tumour xenografts. Heuristic features (area-under-curve and rate-of-enhancement) were calculated from tumour voxel enhancement curves for each imaging modality. Clustering algorithms (k-means clustering and Gaussian mixture modelling) were applied to these features and native tissue T1 to investigate their utility in characterising physiological heterogeneity in tumours. Efficacy in identifying large regions where there is agreement between features is shown. Further optimisation is needed to optimise the approach to characterise smaller, and potentially important, regions where there is a lack of concordance between features.
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| 4330 | Computer #63 |
Automatic sodium maps reconstruction using PatchMatch algorithm for phantom detection |
1Translational Imaging Group, Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 2NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom, 3Brain Repair & Rehabilitation, UCL Institute of Neurology, University College London, London, United Kingdom, 4Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy |
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Quantitative sodium magnetic resonance imaging (23Na-MRI) enables the non-invasive measurement of in vivo total 23Na concentration (TSC) in the human brain. This involves a complex process of reconstructing datasets acquired to calculate a TSC map. Quantitative TSC map calibration relies on external reference phantoms with known concentration for linear calibration. This commonly involves manually segmenting the phantoms by trained raters, hindering automatic image analysis, and presenting a bottleneck in the TSC computation. We propose to substitute the manual segmentation by OPAL, a novel, fast, robust and reliable technique for segmenting sodium phantoms that allows fully-automatic reconstruction of TSC maps. |
| 4331 | Computer #64 |
Dynamic Whole-Brain Connectivity underlying Abnormal Brain States in Late-onset Depression |
1Biomedical Engineering, Peking University, Beijing, China, People's Republic of, 2Biomedical Engineering, Emory University & Georgia Institute of Technology, Atlanta, GA, United States, 3University of Shanghai for Science & Technology, Shanghai, China, People's Republic of, 4Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China, People's Republic of, 5School of Life Science and Technology, Xidian University, Shaanxi, China, People's Republic of, 6Department of Psychosomatics and Psychiatry, ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, China, People's Republic of |
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We conducted dynamic whole-brain connectivity analysis in Late-onset depression (LOD) to investigate alterations in brain networks. All subjects’ ROI-to-ROI dynamic FC were explored using a data-driven method to obtain the most explanatory states. Each state indicate a particular ROI-to-ROI FC pattern. The property of each state were determined based on its scores across time. Besides decreased FC in normal state, we found LOD patients switch between brain states more frequently and tend to enter LOD-risk states, due to and its high states variance and dominating increased FC in LOD-risk states. These results suggest neural mechanisms of disorder from dynamic perspective. |
| 4332 | Computer #65 |
Application of Partial Least Squares regression for Fast and Robust Dictionary Matching for Magnetic Resonance Fingerprinting |
1Medical Imaging Research Center, Dayananda Sagar Institutions, Bangalore, India, 2Institute of Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland |
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The step size of the parameters used for simulation of dictionary determines the parameters being determined. Partial Least squares (PLS) can be used as a general frame work for fast and robust dictionary matching. Regression co-efficient matrix obtained from PLS can be used for localizing the different brain tissue types thus avoiding iterative searching. The increase in contrast between the grey matter and white matter can be attributed to the intermediate values generated by PLS based matching. PLS matches comparatively better at low SNR images compared to the straight forward dot product method. |
| 4333 | Computer #66 |
Cluster Analysis of Dynamic Contrast-Enhanced MRI Pharmacokinetic Parameters for Prostate Cancer Risk Stratification: a Step towards Practical Translation |
1Radiology/Wright Center of Innovation, The Ohio State University, Columbus, OH, United States, 2Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA, United States, 3Urology, The Ohio State University, Columbus, OH, United States, 4Pathology, The Ohio State University, Columbus, OH, United States, 5Radiology, The Ohio State University, Columbus, OH, United States, 6Robotic Urologic Surgery, OhioHealth Dublin Methodist Hospital, Dublin, OH, United States |
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Feasibility of classifying PCa into clusters based on microcirculatory features has the potential to predict outcome and assist in therapeutic treatment of PCa. |
| 4334 | Computer #67 |
Pulmonary Imaging Biomarkers of COPD for Personalized Treatment and Better Outcomes |
1Robarts Research Institute, The University of Western Ontario, London, ON, Canada, 2Credit Valley Hospital, Mississauga, ON, Canada, 3Department of Medicine, The University of Western Ontario, London, ON, Canada |
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In this proof-of-concept demonstration, we developed and generated multimodal-parametric-response-mapping (mPRM) from CT and MRI pulmonary measurements to phenotype chronic obstructive pulmonary disease (COPD). We performed principal component analysis of the voxel distribution generated from co-registered inspiration or expiratory CT with 3He MRI SV cluster maps and 3He MRI ADC maps for ex-smokers with and without COPD. Further work is necessary to determine the appropriate combination of imaging biomarkers generated from MRI and CT to provide useful information in deeply phenotyping COPD. |
| 4335 | Computer #68 |
Brain Connectivity Analysis of Parkinson's Disease and “Scans Without Evidence for Dopaminergic Deficit" Patients |
1Lisbon School of Health Technology-ESTeSL, Lisbon, Portugal, 2Spitalzentrum Biel, Biel, Switzerland, 3Institute of Biophysics and Biomedical Engineering, Faculty of Sciences of the University of Lisbon, Lisbon, Portugal, 4Centre for Neuropsychopharmacology, Imperial College London, London, United Kingdom |
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In this work we propose a comparison study between “Scans Without Evidence for Dopaminergic Deficit" (SWEDD) and Parkinson’s Disease (PD) patients against healthy subjects using the MIBCA toolbox. Here, we studied the difference in imaging and connectivity metrics obtained from anatomical (T1-weighted) and structural (Diffusion Tensor Imaging) data between the three groups. Results showed increased mean diffusivity in the frontal pole, rostral middle frontal gyrus and superior frontal gyrus between SWEDD and PD patients, which can be related with the dopaminergic mesocortical pathway degeneration in PD. These preliminary results help clarify the differences between SWEDD and PD patients. |
| 4336 | Computer #69 |
Resolving ambiguity in T1 mapping using complex MRI data |
1Departments of Medical Informatics and Radiology, Erasmus MC, Rotterdam, Netherlands, 2Imaging Science and Technology, Delft University of Technology, Delft, Netherlands |
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We have recently developed an optimized T1 mapping protocol for carotid atherosclerotic plaque imaging, using a combination of inversion and recovery prepared acquisitions. This protocol requires less images to be taken (and thus shorter acquisition time) for precise T1 estimation than conventional inversion-prepared or saturation-prepared acquisition schemes. However, estimating T1 from magnitude data, acquired with the optimized settings, causes bimodality of T1 estimates, due to the ambiguity in sign of the inversion prepared magnitude images. Simulations and experiments on a hardware phantom and a volunteer show that the ambiguity resolves when we fit a complex-valued model to the complex data. |
| 4337 | Computer #70 |
Comparing MRI texture heterogeneity with MTR and myelin water fraction as measures of myelin integrity |
1Bachelor of Health Sciences, University of Calgary, Calgary, AB, Canada, 2Biomedical Engineering Program, University of Calgary, Calgary, AB, Canada, 3Computer Science, University of Calgary, Calgary, AB, Canada, 4Radiology and Clinical Neurosciences, University of Calgary, Calgary, AB, Canada |
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Changes in myelin integrity are associated with many neurological diseases. We acquired 9.4T MRI from healthy mouse brain to evaluate the utility of texture heterogeneity in T2-weighted MRI for assessing myelin integrity, in comparing with proposed measures including magnetic transfer ratio and myelin water fraction. Measurements were focused on the corpus callosum, with both anatomical (genu, body, splenium) and hemispheric (left, center, right) locations evaluated. All 3 methods showed the uniformity of myelin in corpus callosum between hemispheres, and no significant differences between anatomical locations were detected. Texture heterogeneity showed the best consistency between animals and deserves further verification. |
| 4338 | Computer #71 |
Color mapping in medical imaging - you're (probably) doing it wrong |
1University of Münster, Münster, Germany |
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Some imaging software packages do not accurately display datasets due to difficulties in color mapping. We show some of the shortcomings an three of the most widely used tools (FSL, SPM, FreeSurfer) and provide an easy fix that can be applied to correct the images output by these tools. |
| 4339 | Computer #72 |
T1 Mapping through Bayesian Analysis with Spatial Information Collaboration (BASIC) using Steady-State-Based Imaging Data |
1NIA, NIH, Baltimore, MD, United States |
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We introduce two Bayesian-based analyses that use spatial information as a prior to improve the quality of voxel-by-voxel T1-mapping from spoiled gradient recalled echo (SPGR) imaging data. These approaches, called BASIC, combine voxel-by-voxel fitting with region-of-interest (ROI) parameter estimation. ROI parameters act as a constraint, while voxel fitting mitigates blurring and detail loss. The results were compared with those derived using a conventional nonlinear least-squares-based algorithm. Estimation of T1 from SPGR imaging data was markedly improved through use of the BASIC methods. |
| Exhibition Hall | Thursday, May 12, 2016: 13:30 - 14:30 |
| 4340 | Computer #1 |
Investigation of Varied Readout Sequences Impact on the Amide Proton Transfer Contrast |
1GE Healthcare, Taipei, Taiwan, 2GE Healthcare MR Research China, Beijing, China, People's Republic of, 3PLA general hospital, Beijing, China, People's Republic of |
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The aim of this study was to understand whether amide proton transfer (APT) contrast on brain tumor patient will be impacted by applying three different imaging sequences, spin-echo EPI, single-shot FSE, and a recent developed 3D FSE spiral. Although our finding on APT contrast appears to be similar among various sequences, careful consideration may be required when choosing the appropriate CEST readout sequences for your own applications. |
| 4341
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Computer #2 |
2HG Optimized PRESS MRS for Metabolic Profiling of IDH-mutant Gliomas in Patient-Derived Orthotropic Mouse Model of Human Brain Tumor |
1Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 2Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States, 3Department of Radiology, UT Southwestern Medical Center, Dallas, TX, United States |
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2-Hydroxyglutarate (2HG) is elevated in gliomas harboring IDH1 or IDH2 mutations, and can be a biomarker for the diagnosis of IDH-mutant gliomas. The present study was undertaken to develop PRESS MRS Methodology for 2HG-detection with enhanced precision, and studying 2HG kinetics together with metabolic profiling in Patient-Derived Xenograft Orthotropic Mouse model. In-vivo PRESS MRS was performed at an optimized long-TE of 96ms. A large inverted-signal of 2HG at 2.25-ppm was obtained from IDH-mutant gliomas, well separated from neighboring signals of positive-polarity, with minimal interference from macromolecules. The method was successfully employed to detect 2HG and brain metabolism with tumor progression. |
| 4342 | Computer #3 |
Cerebral blood volume MRI elucidates the impact of ERK1 on high grade glioma growth and invasion |
1Berlin Ultrahigh Field Facility, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany |
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Glioma progression involves complex interactions of tumor vasculature and infiltrating anti-tumor immune cells. As we previously found that mouse lacking ERK1 formed significantly smaller tumors, it was still not clear whether ERK1 deletion in the tumor vascular architecture might influence the outcome of glioma growth. To further study this, we examined the relative cerebral blood volume (rCBV) in the glioma tumor. R2* changes induced by a blood-pool contrast agent, ferumoxytol, were quantified. Here, we established a model system to noninvasively monitor brain tumor angiogenesis, and found evidence supporting the role of ERK1 in regulating glioma growth via angiogenesis. |
| 4343 | Computer #4 |
Dynamic Contrast Enhanced perfusion MRI in pediatric brain tumors |
1Healthcare, Philips India ltd, Gurgaon, India, 2Healthcare, Philips India ltd, Bangalore, India, 3Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, India |
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Perfusion Studies in Pediatric Brain Tumors is a less explored area due to technical challenges of performing contrast enhanced perfusion in infant and children. This study is the first preliminary study reported in Dynamic Contrast Enhanced MRI perfusion involving both high grade and low grade brain tumors. Purpose of this study is to quantify the range of various perfusion metrics in high and low grade tumor as well as normal gray and white matter regions of brain. This ongoing study shows significant statistical difference in cerebral blood volume and fractional plasma volume in high grade and low grade tumor population. |
| 4344 | Computer #5 |
Adiabatic T2-Prepared 3D Fast Gradient Echo Imaging for Brain Tumor Studies at 7T |
1Department of Radiology, University of California at San Francisco, San Francisco, CA, United States, 2GE Healthcare, Waukesha, WI, United States |
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Mechanisms to create a homogenous T2 contrast at 7T should be robust to both B0 and B1 inhomogeneities. This issue was addressed by applying a zero-degree BIR-4 adiabatic pulse for T2 preparation. Simulation and in vivo experiments in mouse brain verified the robustness and contrast of the preparation scheme at 7T. Application of this method was further demonstrated in a study of a patient with a brain tumor. The adiabatic T2 weighting showed high intensity in the region of the tumor, suggesting that the proposed method is likely to be useful in screening and characterizing tumors. |
| 4345 | Computer #6 |
Comparing the CEST imaging of Cerebral Glioma using APT and LOVARS |
1Henan Provincial People’s Hospital, Zhengzhou, China, People's Republic of, 2Zhengzhou, China, People's Republic of, 3Baltimore, MD, United States, 4Beijing, China, People's Republic of, 5Macquarie Park, Australia |
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To evaluate the value of length and offset varied saturation (LOVARS) in the diagnosis of gliomas, and compared with amide proton transfer (APT), We performed the study using LOVARS and APT imaging technique .And we found that APT images is useful in distinguishing low-grade and high-grade glioma, while LOVARS phase images shows better contrast between glioma and peripheral tissue, and the internal heterogeneous components of the glioma. |
| 4346 | Computer #7 |
Chemotherapy increases anti-correlation between default mode and attention networks |
1General Electric Global Research, Bangalore, India, 2General Electric Healthcare, Madrid, Spain, 3Departamento Diagnostico por la imagen, Hospital Universitario Quiron, Madrid, Spain, 4Departamento de Oncología Médica, Hospital Universitario Quiron, Madrid, Spain |
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More than three-fourth of chemotherapy treated cancer survivors have cognitive impairment, including memory loss, inability to think, lasting several years after completion of therapy, sometimes labelled as ‘chemobrain’. Previously, the default mode network (DMN) has been shown to be specifically vulnerable to chemotherapy. In this study we study changes in DMN connectivity after chemotherapy within the same patients. In healthy adults, the DMN is anti-correlated to task positive networks. We observe an increase in this anti-correlation between DMN regions and task positive network regions post-chemotherapy. |
| 4347 | Computer #8 |
Predicting overall survival in glioblastoma patients from DTI, DCE and DSC MRI data acquired prior to surgery and post-chemoradiotherapy |
1Centre for MR Investigations, Hull York Medical School at University of Hull, Hull, United Kingdom, 2Hull York Medical School at University of Hull, Hull, United Kingdom, 3Hull and East Yorkshire Hospitals NHS Trust, Hull, United Kingdom |
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DTI, DCE and DSC MRI parameters obtained pre-surgery and post-chemoradiotherapy were used to predict overall survival in a cohort of patients with glioblastoma multiforme. Results suggest that preoperative diffusivity measurements contain prognostic information about survival. Following chemoradiotherapy, Ktrans, ve, rCBV and tumour volumes were found to have significant prognostic value with higher values associated with shorter overall survival. Cox regression analysis identified 2 volumes and 2 MR parameters, confirming the Kaplan-Meier findings that preoperative DTI and post-chemoradiotherapy DCE parameters have added prognostic value to more traditional prognostic features such as tumour volume. |
| 4348 | Computer #9 |
Optimizing Magnetization Prepared Rapid Gradient Echo (MPRAGE) for Brain Tumor Detection |
1The Ohio State University, Columbus, OH, United States, 2Radiology, Nationwide Children’s Hospital, Columbus, OH, United States, 3Center for Perinatal Research, Nationwide Children’s Hospital, Columbus, OH, United States |
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Gadolinium based contrast agents decrease T1 times in pathologic regions of the brain and improve image contrast and lesion visualization with increased sensitivity and specificity. Magnetization Prepared Rapid Gradient Echo (MPRAGE) sequence offer thinner slices, near seamless reformatting options, and lower specific absorption rates than 2D spin-echo based technique. In this study, we optimize MPRAGE sequence using computer simulation to improve brain tumor enhancement and detection. Compared with a Siemens default MPRAGE sequence, our optimized protocol greatly shortened scan time by around 60% without sacrificing tumor delectation sensitivity. |
| 4349 | Computer #10 |
Diffusional kurtosis imaging for differentiating between high-grade glioma and primary central nervous system lymphoma |
1Affiliated Huashan Hospital of Fudan University, Shanghai, China, People's Republic of, 2The 307th Hospital of Chinese People’s liberation Army, Beijing, China, People's Republic of, 3MR Research China, GE Healthcare, Beijing, China, People's Republic of |
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This study provided a new non-invasive method to better discriminate between high-grade gliomas and primary nervous system lymphomas. We found the kurtosis parameters (MK and K//) showed more obvious differences that can be used for differentiating between these two types of tumors than diffusion parameters (FA, MD, λ// and λ⊥). The ROC curve analysis showed MK and K// had the largest area under curve, which further confirmed that the kurtosis parameters MK and K// could better separate these tumors than traditional diffusion parameters. |
| 4350 | Computer #11 |
Automated extraction of glioblastoma tumor sub-components using multi-modal MRI |
1Diagnostic and Interventional Imaging, The University of Texas Health Science Center at Houston, Houston, TX, United States, 2Neurosurgery, The University of Texas Health Science Center at Houston, Houston, TX, United States |
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Automated quantification of tumors and its components are important in monitoring disease status in glioblastoma patients. We have proposed an automatic segmentation procedure based on morphological grayscale reconstruction techniques to classify and identify tumor sub-regions using multi-modal MRI. |
| 4351 | Computer #12 |
Characterizing metabolic profiles in non-enhancing gliomas using 3D MRSI |
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States, 2Tobacco-Related Disease Research Program, University of California, Oakland, CA, United States |
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This study evaluated the metabolite profiles that were acquired using short and long echo time (TE) magnetic resonance spectroscopic imaging (MRSI) for forty patients with non-enhancing gliomas, including 25 grade 2 and 15 grade 3 gliomas. Metabolite differences were detected between the lesions and white matter, as well as between grades. There were also differences in the T2 values between metabolites within the lesions that could influence the Cho/NAA ratios between short and long TE MRSI. |
| 4352 | Computer #13 |
Enhanced brain labeling by atlas registration in Neuro-oncology using virtual tumor shrinking |
1General Electric Global Research, Bangalore, India, 2University of California at San Francisco, San Francisco, CA, United States, 3Diagnostic Imaging and Biomedical Technologies, General Electric Global Research, Bangalore, India |
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In this work, we address the problem of registration of brain images to atlases in presence of large, space-occupying tumor pathologies. We provide an integrated registration framework to address two types of tumors - a) infiltrating tumors - which penetrate the surrounding tissues b) extrinsic tumors - which grow and compress the surrounding tissues. We propose a mathematical model to shrink extrinsic tumors before registration, thereby reversing the compression effects. |
| 4353 | Computer #14 |
Improved Modeling of Glioblastoma Proliferation and Necrosis using Growth Parameters Derived from MRI |
1University of California, Los Angeles, Los Angeles, CA, United States, 2Harvard University, Boston, MA, United States |
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We outline a new model for the proliferation and necrosis of glioblastoma multiforme. Our approach uniquely accounts both for the anisotropic migration of tumor cells through brain parenchyma and for central tumor necrosis. Model parameters relating to cell division, cell migration, and tumor necrosis are estimated directly from serial MR imaging to generate a customized growth profile for each tumor. The proposed model is shown to replicate observed tumor growth more closely than existing techniques. We anticipate that improved modeling of tumor growth profiles will enable more effective tailoring of treatment regimens. |
| 4354 | Computer #15 |
Quantitative DCE-MRI for differentiating high grade glioma recurrence from treatment-related changes: Effect of T1 mapping method |
1The Ottawa Hospital, Ottawa, ON, Canada, 2Ottawa Hospital Research Institute, Ottawa, ON, Canada, 3University of Ottawa, Ottawa, ON, Canada, 4Carleton University, Ottawa, ON, Canada, 5University of Toronto, Toronto, ON, Canada, 6Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON, Canada, 7Siemens Healthcare GmbH, Erlangen, Germany |
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After a patient has received treatment for a high grade glioma, a new enhancing lesion presents a common diagnostic dilemma: Malignant tumor recurrence and benign treatment-related changes (TRC) appear similar on conventional MRI. MRI tracer kinetic studies may help distinguish recurrence from TRC. We investigated whether Ktrans measurements using quantitative DCE-MRI can accurately diagnose recurrence. We also studied the effect of the DCE T1 mapping method (VFA versus LL). Ktrans values in recurrent tumor were higher than in TRC, providing sensitivity of 69-77%, specificity of 100%. The choice of T1 mapping had little effect on diagnostic accuracy. |
| 4355 | Computer #16 |
Differentiation of Glioblastoma from Brain Metastasis: Qualitative and Quantitative Analysis using Pseudo-continuous Arterial Spin Labeling MR Imaging |
1Radiology, Seoul National University Bundang Hospital, Seongnam, Korea, Republic of, 2Seoul National University College of Medicine, Seoul, Korea, Republic of, 3Radiology, Seoul National University Hospital, Seoul, Korea, Republic of, 4Radiology, Seoul National University Healthcare System Gangnam Center, Seoul, Korea, Republic of |
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Arterial spin labeling (ASL) magnetic resonance (MR) imaging could be used to assess the tumor blood flow (TBF). To distinguish glioblastoma (GBM) from brain metastasis, we compared TBF between the two groups by using visual grading and quantitative analyses. Both intratumoral and peritumoral blood flow were significantly higher in GBM than in brain metastasis. We propose that ASL-TBF can aid in differentiating GBM from brain metastasis either by qualitative or by quantitative methods. |
| 4356 | Computer #17 |
Changes in DTI and DSC Parameters as Markers for Assessing Treatment Response in Glioblastomas |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States, 3Radiation Oncology, University of Pennsylvania, Philadelphia, PA, United States, 4Neurosurgery, University of Pennsylvania, Philadelphia, PA, United States, 5Hematology-Oncology, University of Pennsylvania, Philadelphia, PA, United States, 6Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom |
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The study was performed to determine whether changes in DTI and DSC parameters can aid in differentiating glioblastomas with pseudo-progression (PsP) from true-progression (TP) and partial response. MRI data from thirty patients with these diagnoses (based on pathological evaluation and clinical follow-up) were included. All patients underwent two MR scans before pathological confirmation. A significant increase in median rCBV and rCBVmax value was noted in TP compared with PsP, while none of the DTI parameters showed significant differences between groups. Our preliminary results indicate that changes in rCBV may be helpful in identifying PsP from TP. |
| 4357 | Computer #18 |
Which is the best predictor for histological grade of glioma: DWI, MRS, 11C-methionine -, and 18F-fluorodeoxyglucose -PET |
1Radiology, Ehime University School of Medicine, Ehime, Japan, 2Neurosurgery, Ehime University School of Medicine, Ehime, Japan |
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Various imaging modalities are commonly used for preoperative examinations of brain tumors. Here we evaluated the specificity of ADC, MRS, and PET-CT to predict the WHO glioma grade and identified potential correlations with the Ki-67 index as a marker of tumor cell proliferation. In this limited patients series, minimum ADC was the best predictor of the histological glioma grade and it was also significantly negatively correlated with the Ki-67 index indicating its potential as a reliable marker of cellular proliferation. |
| 4358 | Computer #19 |
Histogram analytics and data mining of multiparametric FMRI (perfusion, diffusion) in preoperative histologic prediction of posterior fossa tumors. |
1Radiology, Baylor College of Medicine, Bellaire, TX, United States, 2Medical Imaging, King Fahad Medical City, Riyadh, Saudi Arabia, 3Pathology and Laboratory Medicine, King Fahad Medical City, Riyadh, Saudi Arabia, 4KFMC-Riyadh, Riyadh, Saudi Arabia, 5Radiology, King Fahad Medical City, Riyadh, Saudi Arabia, 6King Fahad Medical City, Riyadh, Saudi Arabia, 7IGI Technologies, College Park, MD, United States, 8Johns Hopkins Aramco Healthcare, Dhahran, Saudi Arabia |
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Histogram metrics derived from a combination preoperative MRI: AFDC and perfusion maps, appear to be promising in differentiation of posterior tumors |
| 4359 | Computer #20 |
Perfusion MRI as the predictive/prognostic and Pharmacodynamic Biomarkers in Recurrent Malignant Glioma Treated with Bevacizumab: A Systematic Review and a time-to-event meta-analysis |
1Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea, Republic of, 2National Evidence-based Healthcare Collaborating Agency, Seoul, Korea, Republic of |
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The current evidence in the literature shows that the rCBV of DSC-MRI is the most widely used perfusion MRI parameter. The rCBV can be used to predict disease progression and overall survival in patients with recurrent malignant glioma treated with BVZ. Various perfusion MRI parameters from DSC-MRI and DCE-MRI could play a role as pharmacodynamic biomarkers to evaluate the drug’s anti-angiogenic effect on tumor. |
| 4360 | Computer #21 |
Is there an optimal acquisition delay for postcontrast quantitative MRI of brain metastasis? |
1Seoul National University Hospital, Seoul, Korea, Republic of, 2MR Applications and Workflow, GE Healthcare, Seoul, R.Korea, Seoul, Korea, Republic of, 3SNUH healthcare system gangnam center, Seoul, Korea, Republic of, 4Department of Radiology, Seoul National University Hospital, Seoul, Korea, Republic of |
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In the brain metastasis, T1 shortening after the administration of gadolinium contrast agent may vary with the timing of contrast administration. Synthetic MRI enables quantitative measurements with relatively short times. Our study aimed to determine the optimal acquisition delay for quantitative imaging of brain metastases with contrast-enhanced synthetic MRI. This study revealed that there was no significant difference and relationship in the histogram parameters between three different delay time points of immediately, 8 minutes and 20 minutes after the contrast injection. Therefore, postcontrast quantitative MRI might be acquired regardless of time within 20 minutes. |
| 4361 | Computer #22 |
Differentiating radiation-induced brain necrosis from glioma recurrence: using 3-Dimensional arterial spin labeling and dynamic susceptibility contrast perfusion MR imaging |
1Radiology, PLA General Hospital, beijing, China, People's Republic of |
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Perfusion made it possible to obtain measurements of vascularity within brain lesions. The vascularity of malignant tumor differs dramatically from that of radiation necrosis. Thus, tumor recurrence within irradiated lesions may be differentiated from regions of radiation necrosis with perfusion. 64 patients were prospectively entered into the study on the basis of the following criteria: previous treatment with radiation therapy after surgical resection for intraaxial tumors; new development of enhancing lesions within the radiation field. To compare 3D-ASL with DSC and to see whether 3D ASL-derived CBF values can be used as an alternative to DSC for their differentiation. |
| 4362 | Computer #23 |
Can cerebral lymphomas and glioblastomas be differentiated based on histogram parameters on contrast-enhanced T1-weighted images? |
1Department of Radiology, University of Fukui, Fukui, Japan, 2Division of Radiology, University of Fukui Hospital, Fukui, Japan |
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Cerebral lymphomas are sometimes difficult to distinguish from glioblastomas based on routine magnetic resonance (MR) examination. Therefore, this study assessed the utility of a histogram analysis of the intratumoral enhanced region, using contrast-enhanced T1WI (CET1WI) with a 3D-spoiled gradient recalled aquisition in the steady state (SPGR) sequence, for cerebral lymphomas and glioblastomas, to determine whether the histogram parameters differed between the two tumors. There was significant difference (p < 0.01) in skewness between lymphomas and glioblastomas. This suggests the possibility of differential diagnosis of cerebral lymphomas and glioblastomas by histogram analysis of CET1WI. |
| 4363 | Computer #24 |
Multiparametric quantitative MRI of meningiomas (H2O, T1, T2*, kurtosis) for microscopic tissue characterization |
1Institute of Medicine and Neuroscience (INM-4), Research Centre Juelich, Juelich, Germany, 2Institute of Neuroscience and Medicine 4 (INM-4), Research centre Juelich, Juelich, Germany, 3Institute of Medicine and Neuroscience (INM-4), Research Centre Juelich, Juelich, Georgia, 4University Hospital Aachen, Aachen, Germany, 5university Hospital Aachen, Aachen, Germany |
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Differentiation between meningioma types has implications in preoperative planning but is seldom achieved by conventional MRI. We investigate a multiparameter quantitative characterization of meningioma in clinically acceptable measurement times characterizing each tumour by its “qMRI fingerprint”. The parameters included are water content, T1, T2* and diffusion maps (MD, FA, MK, axonal water fraction, tortuosity) derived from a diffusion kurtosis acquisition. The “qMRI fingerprints” are distinct for each tumour. |
| Exhibition Hall | Thursday, May 12, 2016: 13:30 - 14:30 |
| 4364 | Computer #25 |
Cell treatment improves recovery after stroke in type two diabetic rats measured by MRI |
1Neurology, Henry Ford Health System, Detroit, MI, United States, 2Physics, Oakland University, Rochester, MI, United States, 3Tianjin Geriatrics Institute, Tianjin Medical University General Hospital, Tianjin, China, People's Republic of |
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With a suture 2-hour occlusion and reperfusion stroke model and a low dose Streptozotocin injection combined with a high fat food diet diabetic model of young adult Wistar rats, longitudinal measurements of MRI demonstrated that bone marrow stromal cell treatment of stroke in type 2 diabetes mellitus rats, compared with the saline treated control rats, not only significantly reduced blood-brain barrier leakage and hemorrhagic spots starting from 1 week and 3 weeks after stroke (p<0.05) measured by contrast enhanced T1WI with Gd-DTPA and identified by SWI, respectively; but also significantly improves white matter remodeling after stroke measured by DSI. |
| 4365
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Computer #26 |
The MIPP study: Monitoring Intracranial atherosclerotic Plaque Progression using high resolution MRI - initial results |
1Radiology, University of California, San Francisco, San Francisco, CA, United States, 2Radiology, Changhai Hospital, Shanghai, China, People's Republic of, 3Radilogy, University of Pittsburgh, Pittsburgh, PA, United States, 4Radiology, University of Cambridge, Cambridge, United Kingdom |
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Intracranial large artery atheroma is a major cause of stroke, however its natural history is still poorly understood. In this study we followed 63 symptomatic patients who had intracranial atherosclerotic plaque for up to 3 years. Multi-contrast black blood vessel wall MRI and clinical brain imaging were performed. Initial results included 22 patients who were followed for 6 months showed an overall plaque volume progression rate of 0.8%, however with a large standard deviation (20.1%) and range (-45.9% to 40.1%). Patients with hypertension or low HDL tended to progress faster. The feasibility of MRI for monitoring intracranial plaque pathological changes was demonstrated. |
| 4366 | Computer #27 |
Simultaneous Time-Encoding for Bi-Polar (STEP) MRA combining Arterial Spin Labeling (ASL) and Phase-Sensitive Inversion Recovery Black-Blood (PSIR-BB) |
1Toshiba Medical Systems, Otawara, Japan, 2Toshiba Medical Research Institute, Vernon Hills, IL, United States |
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We proposed and assessed a simultaneous time-encoding for bipolar MRA technique (STEP-MRA), combining both the 4DASL-MRA of nulling background signals and PSIR BB-MRA with preserving Mz polarities and background stationary signals, which allows simultaneously providing using the same acquired data as the standard 4DASL-MRA. In addition, vessel visualization and SNR were improved by synthesizing multiple TI data. Although further parameter optimization and clinical evaluation are required, our proposed method has a potential to provide various information with limited acquisition data. |
| 4367
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Computer #28 |
High-resolution intracranial vessel wall magnetic resonance imaging in an elderly asymptomatic population: comparison of 3.0T and 7.0T |
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Neurology, University Medical Center Utrecht, Utrecht, Netherlands, 3Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands |
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In recent years, multiple intracranial vessel wall MRI sequences have been developed for direct evaluation of the intracranial vessel wall and its pathology in vivo. These studies have mainly been performed on 3T and 7T field strengths. In the current study, we compared 3T and 7T MRI for visualizing both healthy intracranial arterial vessel wall as well as possible vessel wall lesions. Vessel wall visibility was significantly better at 7T even though there were more artefacts hampering assessment. Overall, more lesions were scored on 7T images; however – surprisingly – only half of all 3T lesions were seen at 7T. |
| 4368
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Computer #29 |
High Resolution Whole Brain Intracranial Vessel Wall Imaging at 3T and 7T |
1Radiology, University of California, San Francisco, San Francisco, CA, United States, 2Neurology, University of California, San Francisco, San Francisco, CA, United States, 3Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States, 4Siemens Healthcare, San Francisco, CA, United States |
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High resolution MRI of the intracranial vessel wall provides important capabilities for the assessment of intracranial vascular disease including atherosclerotic plaques and aneurysms. This study developed and optimized 3D high resolution (0.5mm isotropic) techniques for intracranial vessel wall imaging at 3T and 7T. The abilities of 3T clinical scanners and 7T research scanners were systematically compared through theoretical simulations and in vivo patient studies. We found 3D T1-weighted SPACE sequence could be used for whole brain intracranial vessel wall evaluation at both 3T and 7T. 7T provides significantly better image quality and improves the confidence of diagnosis. |
| 4369 | Computer #30 |
Altered Temporal Dynamics in BOLD Measurements of Vascular Reserve in Children with Sickle Cell Disease |
1Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, ON, Canada, 2Physiology, University of Toronto, Toronto, ON, Canada, 3Medical Imaging, University of Toronto, Toronto, ON, Canada |
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Cerebrovascular reactivity (CVR) measured with BOLD MRI can be robustly acquired by altering blood flow with a square-wave CO2 stimulus. However, the BOLD response to a step change is confounded by a temporal lag and transient period of signal change. Differences in temporal response between different tissues can lead to CVR underestimation. Transfer function analysis (TFA) provides a frequency domain analysis of CVR that is less sensitive to temporal variations. This study compares the results of TFA to conventional CVR analysis in children with and without sickle cell disease. |
| 4370 | Computer #31 |
Diffusion Corrected Aneurysm Wall Permeability as a Measure of Rupture Risk |
1Biomedical Engineering, Northwestern, Chicago, IL, United States, 2College of Medicine, University of Illinois, Chicago, IL, United States, 3Radiology, Northwestern, Chicago, IL, United States |
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We report the first evidence of diffusion corrected DCE-MRI modeled contrast permeability in intracranial aneurysms and show the diffusion model more accurately represents physiology than previous methods. Permeability metrics, as measured in 23 patients, demonstrate a statistically significant trend with rupture risk as defined by anatomic imaging and clinical risk factors. |
| 4371 | Computer #32 |
Estimation of the Evolution of Cerebral Ischemia by MRI with T1 Relaxation Time in Rotating Frame and Apparent Diffusion Coefficient |
1Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, China, People's Republic of, 2Philips Healthcare, Guangzhou, China, People's Republic of, 3Philips Healthcare, HongKong, China, People's Republic of |
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This study was to evaluate the abilities of T1ρ and ADC to estimate the duration of ischemia in human, and focus on clinical application. We take a cross-sectional study to collect patients with brain ischemia in period of time(March 2014 to February 2015), and exploit the characteristics of ADC and T1ρ in brain ischemia in various stages of ischemia and uncover their relationships with ischemia stages. Our results indicate that T1ρ parametric results were elevated in the ischemic lesion, and increased over time of ischemia in a linear fashion. |
| 4372 | Computer #33 |
Assessment of cortical cerebrovascular permeability using 3-dimension pseudo-continuous arterial spin labeling and T1 dynamic contrast enhancement magnetic resonance imaging in moyamoya disease |
1Huashan Hospital, Fudan University, Shanghai, China, People's Republic of, 2MR Research, GE Healthcare, Shanghai, China, People's Republic of, 3Advanced application, GE Healthcare, Beijing, China, People's Republic of |
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In moyamoya disease (MMD), the compensatory collateralization from external cerebral artery or bypass artery is essential to evaluate the severity of disease and perfusion efficacy of surgical revascularization. And the leptomeningeal anastomoses were regarded as significant contributors to the collateral blood supply. However, the characteristic of the compensatory collateralization has not been clarified up to now, such as the permeability of vessels, which could be the reason of rehemarrhage and other complications after the surgical revascularization for MMD. We hypothesize the high permeability of collateralization leads to rehemarrhage in MMD. In this work, quantitative assessment of 3D-pCASL and DCE-MRI suggests no significant increased permeability in the cortical areas with collateral neovascularization in MMD. |
| 4373 | Computer #34 |
T1 weighted, black blood variable flip angle spin echo imaging utilizing variable density, distributed spirals and a low rank reconstruction |
1Medical Physics, University of Wisconsin - Madison, Madison, WI, United States, 2Radiology, University of Wisconsin - Madison, Madison, WI, United States |
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Summary |
| 4374
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Computer #35 |
Intracranial vessel wall and cerebrovascular reactivity imaging provides evidence for mechanistic differences in atherosclerotic and non-atherosclerotic stenotic disease |
1Radiology, Vanderbilt University, Nashville, TN, United States, 2DXP Imaging, Louisville, KY, United States, 3Neurology, Vanderbilt University, Nashville, TN, United States, 4McLean Hospital, Boston, MA, United States, 5University Medical Center Utrecht, Utrecht, Netherlands |
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No study to date has assessed the relationship between intracranial vessel plaque and wall thickening and its impact on tissue-level function. A novel intracranial vessel wall imaging protocol and BOLD imaging were applied in patients with intracranial stenosis secondary to atherosclerosis and moyamoya disease (non-atherosclerotic stenosis). The time of maximum correlation of BOLD data with the applied stimulus, the CVR time, calculated using a novel time regression technique, is prolonged in vascular territories with a proximal vessel wall lesion for both atherosclerosis and moyamoya patients. The maximum z-statistic, a qualitative metric of CVR, is decreased in vascular territories with a proximal vessel wall lesion in moyamoya patients only. |
| 4375 | Computer #36 |
Neurovascular Reactivity in Smokers and Nonsmokers Measured by High-Speed MR Flow Mapping During Volitional Apnea |
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States |
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Smoking is well known to cause vasoconstriction as a result of the formation of reactive oxygen species, which reduce nitric oxide availability. Vasomotor reactivity can be measured in terms of the change in cerebral blood flow in response to a hypercapnic challenge. Here we measured the change in superior sagittal sinus flow at 2-second temporal resolution during breath-hold (a predominantly hypercapnic stimulus) and computed a breath-hold index (BHI) as the slope of the flow velocity-time curve in 20 nonsmokers and 13 chronic smokers. The data suggest reduced BHI in the smoking group (0.252±0.097 vs. 0.306±0.098 cm/s2, p<0.07) indicative of dysregulation of vascular reactivity. |
| 4376 | Computer #37 |
Non-contrast enhanced 4D intracranial MR angiography based on pseudo-continuous arterial spin labelling (PCASL) with the keyhole technique |
1Healthcare, Philips Electronics Japan Ltd., Tokyo, Japan, 2Department of Clinical Radiology, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan, 3Philips Healthcare, Tokyo, Japan, 4Department of Radiology, Tokai University Hospital, Kanagawa, Japan |
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A non-contrast enhanced intracranial three-dimensional dynamic magnetic resonance angiography (4D-MRA) based on pseudo-continuous arterial spin labelling with the keyhole technique (4D-PACK) was implemented. Images acquired from three volunteers were compared with the data acquired without the keyhole technique. We show that the 4D-PACK can accelerate acquisition speed, while keeping flow dynamics information. |
| 4377
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Computer #38 |
Feasibility of Combining Perforating Artery Imaging and Whole Brain Vessel Wall Imaging at 7T |
1State Key Laboratory of Brain and Cognitive Science, Beijing MR Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, People's Republic of, 2Graduate School, University of Chinese Academy of Sciences, Beijing, China, People's Republic of, 3Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 4Xuanwu Hospital, Beijing, China, People's Republic of, 5Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China, People's Republic of, 6Beijing Institute for Brain Disorders, Beijing, China, People's Republic of |
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In this study, we improved TOF-MRA and T1w-SPACE to a higher resolution for imaging perforating arteries and intracranial vessel walls at 7T. With the combination of the two techniques, we are for the first time able to depict the position of perforators and the vessel wall lesion in patients with ICAD. Small changes within the vessel wall may be revealed, and the certainty of the diagnosis may become better established, enabling better therapeutic management. |
| 4378 | Computer #39 |
High-resolution whole-brain intracranial vessel wall MRI at 3T: Technical considerations toward a clinically practical imaging approach to stroke etiology assessment |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Radiology, Xuanwu Hospital, Beijing, China, People's Republic of, 3Bioengineering, University of California, Los Angeles, CA, United States, 4Neurology, Cedars-Sinai Medical Center, Beijing, CA, United States, 5Neurology, Xuanwu Hospital, Beijing, China, People's Republic of, 6Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 7MR R&D, Siemens Healthcare, Los Angeles, CA, United States |
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High-resolution MR using variable-flip-angle 3D fast spin-echo (FSE) has emerged as a promising intracranial vessel wall imaging technique. However, its typical implementations on clinically available MR systems have several limitations. This work aimed to develop a 3D FSE-based method that allows for CSF-attenuated T1-weighted whole-brain vessel wall imaging within 8 min. Volunteer studies were performed during technical optimization. Preliminary clinical validation was conducted in patients with various vessel wall pathologies. The technique demonstrated excellent vessel wall delineation quality, diagnostic accuracy, and patient tolerance. It may potentially become a clinically practical imaging approach to stroke etiology assessment. |
| 4379
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Computer #40 |
Iterative algorithm for the temporal decomposition of the cerebrovascular reactivity dynamic response in neurovascular patients. |
1Department of Neuroradiology, University Hospital Zurich, Zurich, Switzerland, 2Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland |
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Our iterative algorithm evaluates transient phases of BOLD fMRI signal dynamics during a CO2 pseudo-square wave challenge and optimizes CO2 arrival time determination to increase sensitivity and reliability of cerebrovascular reactivity analysis. On 25 healthy controls and unilateral internal carotid occlusion patients, all BOLD-derived parameters maps are normalized in MNI space and combined for reference atlases and assess alterations within single patient. The transient phase durations, temporal delay maps and dynamic and static CVR maps were calculated. We determined the optimal CO2 arrival time and found that excluding the transient phases resulted in the best fit to the physiological data. |
| 4380 | Computer #41 |
Patterns of bold signal responses to progressive hypercapnia enhance the interpretation of underlying cerebrovascular pathologies |
1Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada, 2Department of Physiology, University of Toronto, Toronto, ON, Canada, 3Departments of Anaesthesia, University Health Network, Toronto, ON, Canada, 4Joint Department of Medical Imaging and the Functional Neuroimaging Laboratory, University Health Network, Toronto, ON, Canada, 5Department of Anaesthesia, University Health Network, Toronto, ON, Canada |
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We surveyed the varied patterns of BOLD changes in response to a ramp CO2 stimulus ranging from hypocapnia to hypercapnia in 10 healthy individuals and 10 patients with steno-occlusive disease. The patterns of response fell into 4 types, based on the two linear slopes fitted to each range. Maps of these types on a voxel by voxel basis were compared to cerebrovascular reactivity (CVR) calculated as the linear slope over the whole ramp. We suggest that for assessing cerebrovascular reactivity, CVR and type scoring enhance the interpretation of each other, and that modeling the possible underlying patho/physiologies to explain the type patterns is the portal to further work. |
| 4381 | Computer #42 |
Evaluation of the cross flow for anterior communicating artery aneurysms using 4D-Flow MRI |
1Radiology, Osaka University, Suita, Japan, 2Neurosurgery, Osaka University, Suita, Japan |
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The purpose of this study was to elucidate in vivo analysis of the flow dynamics of ACOM aneurysms from both A1 arteries using 4D-Flow and digital subtraction angiography (DSA). 2 out of 8 ACOM aneurysms showed intra-aneurysm flow from both A1 arteries and 6 other patients showed the unilateral A1 inflow. Inflow findings of all patients are consistent with 4D-Flow and DSA. 4D-FLOW MRI is able to visualize cross flow in ACOM aneurysms. |
| 4382 | Computer #43 |
Functional Reorganization of the Brain in Ischemic Stroke Patients after the Repetitive Transcranial Magnetic Stimulation: a fMRI Study |
1Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College, Beijing, China, People's Republic of, 2Department of Interventional Radiology, China Meitan General Hospital, Beijing, China, People's Republic of, 3State Key Laboratory of Brain and Cognitive Science, Beijing MR Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, People's Republic of, 4Department of Radiology, School of Medicine, University of Pennsylvania, Philadelphia, PA, United States, 5Department of Neurology, Peking Union Medical College Hospital, Peking Union Medical College, Beijing, China, People's Republic of |
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It is a resting-state fMRI( rs-fMRI) study of patients with motor disturbance after acute ischemic stroke. We assessed the functional connectivity (FC) changes of the ipsilesional primary motor cortex (M1) within the brain before and after the repetitive transcranial magnetic stimulation (rTMS) by rs-fMRI. The research not only gave theoretical support of the rTMS treatment in stroke patients but also investigated the cerebral functional changes in motor recovery. |
| 4383 | Computer #44 |
Evaluation of perfusion and hypoxia parameters in healthy subjects and patients with high-grade carotid artery stenosis |
1Department of Neuroradiology, Technische Universität München, Munich, Germany, 2Department of Radiology, Technische Universität München, Munich, Germany, 3Clinic for Neurology, Technische Universität München, Munich, Germany |
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Severe intracranial arterial stenosis (SIAS) is a major health issue as it often accounts for strokes. Here, we present preliminary data from a clinical study in patients with SIAS compared to healthy controls. The major aim was to evaluate the reliability of perfusion and oxygenation related measures by analyzing their hemispheric symmetry to assess their potential diagnostic capabilities. Preliminary results imply symmetry of all measures between hemispheres of healthy controls. Regarding patients, only pCASL-based CBF implies a reduced perfusion on the side of carotid artery stenosis which is in accordance to recent literature and is currently under further investigation. |
| 4384 | Computer #45 |
Arterial Spin Labeling MRI Evaluation of Cerebrovascular Reserve with Acetazolamide in Patients with Sickle Cell Disease |
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Sunnybrook Research Institute, Toronto, ON, Canada, 3Internal Medicine, Academic Medical Center, Amsterdam, Netherlands, 4Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, United States, 5Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, Netherlands |
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Arterial spin labelling perfusion MRI was employed with an acetazolamide challenge to probe the cerebrovascular physiology in patients with sickle cell disease and matched controls. Cerebral blood flow was estimated at baseline and cerebrovascular reserve(CVR) was calculated after vasodilation with acetazolamide. We found that patients had limited CVR compared to controls, and that the patients with the highest CBF at baseline also had the smallest response to acetazolamide. ASL-based CBF measurements with ACZ showed robust CVR results indicating the cerebral hemodynamics of some patients may be impaired. |
| 4385 | Computer #46 |
Amide Proton Transfer-Weighted MR Imaging Signal as Predictor of Non Thrombolysis Treatment Efficiency for Stroke |
1Beijing Hospital, Beijing, China, People's Republic of, 2Johns Hopkins University, Baltimore, MD, United States |
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This study is to evaluate the longitudinal Amide Proton Transfer-weighted (APTw) signal changes in patients with stroke after treatment. APT weighted images of stroke patients was acquired, including non-treatment and post treatment. 91.7% patients (22/24) showed gradual increased APT values with the extension of time, accompanied with the clinical symptoms improvement. The other 2 patients (8.3%) showed further decreased APT values in the second scan (the first scan after treatment), accompanied with the clinical symptoms aggravation. The increase of APT weighted signal may indicate the improvement of clinical symptoms while the decrease may indicate the aggravating of clinical symptoms. |
| 4386 | Computer #47 |
Diffusion kurtosis imaging for preliminary analysis of micro-structural changes of brain tissue affected by acute ischemic stroke |
1Radiology, Xiamen Second Hospital, Xiamen, China, People's Republic of, 2MR Research China, GE Healthcare, Beijing, China, People's Republic of, 3Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States |
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One hundred and thirteen patients with acute ischemic stroke underwent DKI sequence scanning. 131 lesions were outlined and divided into six groups. The changed percentages of DKI indices (FA%, MD%, Da%, Dr%, MK%, Ka%, Kr%) relative to normal contra-lateral ROI were computed. The statistical analysis results illustrated that there was a trend that when the acute ischemic stroke affected tissue mostly contained white matter, the complexity of micro-structure changes of the tissue was much higher than other affected locations. Also, the kurtosis-derived parameters presented to have greater potential in distinguishing each group. |
| 4387 | Computer #48 |
Evaluation of Retrograde Embolization in Cryptogenic Stroke by Aortic 4D flow MRI and 3D TOF MRA |
1Northwestern University, Chicago, IL, United States |
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The purpose of this study was to employ aortic 4D flow MRI and brain TOF MRA for the evaluation of retrograde diastolic flow from the descending aorta into the supra-aortic vessels as a mechanism for embolic stroke. In 35 cryptogenic stroke patients, 4D flow MRI demonstrated close to 50% concordance with stroke location on imaging with retrograde diastolic flow into the feeding vessels of the affected cerebral area, identifying a potential etiology for cryptogenic stroke. Our findings further document the importance of taking into account variants in cerebrovascular anatomy which identified retrograde embolization risk in an additional 14% of subjects. |
| Exhibition Hall | Thursday, May 12, 2016: 13:30 - 14:30 |
| 4388 | Computer #49 |
Characterization of Regional and Longitudinal Changes in Z-spectra of Spinal Cord Injury |
1Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, 2Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 3Biomedical Engineering, Vanderbilt University, Nashville, TN, United States |
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Non-human primates provide a valuable pre-clinical model for studying spinal cord injuries. Here we examine the fingerprints in the Z-spectra of abnormal tissues and cysts surrounding the lesion site after spinal cord injury, regionally and longitudinally. Characteristic chemical exchange saturation transfer (CEST) and nuclear Overhauser enhancement (NOE) effects extracted from Z-spectra may enable the non-invasive assessment of spontaneous recovery from traumatic injury. |
| 4389 | Computer #50 |
In Vivo Proton Magnetic Resonance Spectroscopy Reveals Metabolite Changes in a Rat Model of Kainic Acid Induced Spinal Cord Injury |
1Department of Diagnostic Radiology, University of Louisville School of Medicine, Louisville, KY, United States, 2Departments of Neurological Surgery, Anatomical Sciences & Neurobiology, and Bioengineering, University of Louisville School of Medicine, Louisville, KY, United States, 3Department of Bioengineering, University of Louisville School of Medicine, Louisville, KY, United States |
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Current study was to focus on the proton MRS detection of metabolite profile of spinal cord gray matter just caudal to a kainic acid injury in rats 14 days after administration of the excitotoxic agent, and further to correlate the MRS findings to the histopathology of the animal model. Quantitative evaluations of different metabolites were also performed to identify potential MR based biomarkers of neurotoxicity. |
| 4390 | Computer #51 |
In vivo T1 mapping of the spinal cord using a reduced Field-of-View Inversion Recovery sequence (IR-ZOOM-EPI) |
1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom, 2Philips Healthcare, Guildford, United Kingdom, 3Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy |
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The T1 relaxation time is a fundamental quantitative Magnetic Resonance parameter widely used to characterize healthy and pathological tissue. However, investigation of quantitative T1 in the human spinal cord has been limited to date. In this work, we propose a scan time efficient protocol in the spinal cord for Inversion Recovery T1 mapping, which is considered the “gold-standard” method. The mean (± standard deviation) T1 for white matter and grey matter in the cervical spinal cord were found to be respectively 1096 (±26) ms and 1153 (±24) ms. |
| 4391 | Computer #52 |
Demyelination and remyelination: frequency shift assessment in lysolecithin rat model |
1MRI Research Center, University of British Columbia, Vancouver, BC, Canada, 2Research Scientist, University of British Columbia, Vancouver, BC, Canada, 3Radiology, University of British Columbia, Vancouver, BC, Canada |
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GRE images provide strong gray/white matter contrast that is determined by the local MR resonance frequency, which has been shown to be strongly influenced by the local tissue microstructure. While studies have looked at well-defined architectures in rat spinal cord to study this biophysical mechanism, the specific effects of axon/myelin microstructure on frequency shifts is difficult to evaluate independently. Using lysolecithin to induce chemical demyelination while preserving axonal integrity, we assess predominantly myelin-related effects on frequency shifts in rat dorsal column as it demyelinates/remyelinates, providing insight important to applications of frequency shift mapping to demyelinating diseases such as multiple sclerosis. |
| 4392 | Computer #53 |
A comprehensive assessment of cervical cord lesions in patients with multiple sclerosis on T1-MPRAGE at 3T: relationship with cord atrophy and disability |
1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Clinical Neurology Department, Faculty of Medicine, Al-Azhar University, Cairo, Egypt, 3Xinapse System Ltd, West Bergholt, Essex, United Kingdom, 4Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 5Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy |
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In this study, we performed a comprehensive assessment of cervical cord lesions in 133 patients with multiple sclerosis (MS) on 3D T1-weighted scans at 3.0 T. Lesion occurrence, regional distribution, influence on cord atrophy and disability were evaluated. T1 lesions were detected in a large proportion (85%) of MS patients, with a higher frequency of cord lesions in the progressive than in the relapsing forms of the disease. There was only a modest correlation between cord T1 lesions and atrophy. Both cord T1 lesions and atrophy were significant and independent contributors to patient disability. |
| 4393 | Computer #54 |
Single acquisition multiple contrast spine MRI using accelerated quantitative mapping |
1Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States, 2Global MR Applications & Workflow, GE Healthcare, Houston, TX, United States, 3Department of Imaging Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States, 4Synthetic MR Technologies AB, Stockholm, Sweden |
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Recently, several techniques for rapid simultaneous mapping of proton density and T1, T2 relaxation parameters from a single acquisition and generation of synthetic images of any desired image contrast have been demonstrated, mostly in the brain. Such an approach could potentially shorten a spine MRI exam which typically consists of multiple 2D acquisitions with different contrast weightings. But even routine spine MRI is fraught with technical challenges such as motion and inhomogeneity. So in this work we explore the feasibility of obtaining synthetic MRI images of usable image quality in the spine using a 2D quantitative mapping technique. |
| 4394 | Computer #55 |
Detection of Stellate Ganglion and Thoracic Sympathetic Chain Ganglia on Non-contrast CISS MRI |
1Diagnostic Radiology, Johns Hopkins Medical Institute, Elkridge, MD, United States, 2Neuroradiology, Johns Hopkins Medical Institute, Baltimore, MD, United States, 3Radiology, Johns Hopkins Medical Institute, Baltimore, MD, United States, 4Radiology, Johns Hopkins, Baltimore, MD, United States, 5Radiology, Hospital of Special Surgery, New York, NY, United States |
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Thoracic sympathetic chain ganglia can be readily seen and well characterized on pre-contrast 3D-CISS MRI. This technique can aid in initial evaluation of potential stellate and/or SCG pathology as well allow for post-treatment follow-up. |
| 4395 | Computer #56 |
Magnetisation Transfer Ratio (MTR) Measurements in the Lumbar cord: A Pilot Study using ZOOM-EPI at 3T |
1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom, 2Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy |
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The Magnetisation Transfer Ratio (MTR), and quantitative Magnetisation Transfer (MT) parameters have proven to be sensitive to the diseased spinal cord (SC), however in vivo quantitative imaging of the cord is challenging. Rapid acquisition sequences such as Echo Planar Imaging (EPI) are desirable but may suffer from artefacts and image distortions. Here we present results from the use of single-shot ZOOM-EPI to reduce acquisition time and distortions in SC MTR mapping. The mean SC MTR value for 9 subjects was 38.8 (±4.05). The mean scan-rescan coefficient of variation for measuring SC MTR (from 5 subjects) was 4.39%. |
| 4396 | Computer #57 |
Functional connectivity in spinal cord for clinical translation |
1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, 2Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States |
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Spinal cord functional magnetic resonance imaging studies have previously used task-based paradigms, but we recently showed the existence of resting state networks within the cord at 7 Tesla. More recently we have successfully translated the acquisition, preprocessing, and analysis methods developed at 7 Tesla to more clinically relevant 3T scanners. Our results suggest that a run of approximately 6 mins is sufficient at 3T if resting state signals undergo bandpass filtering with frequencies up to 0.17 Hz. Thus, functional connectivity measures in the cervical cord are practical for widespread clinical applications for studying diseases of the central nervous system. |
| 4397 | Computer #58 |
MRI of the thoracic spinal cord in multiple sclerosis at 7T |
1NINDS, NIH, Bethesda, MD, United States, 2INSERM U1127/CNRS UMR7225, CENIR, Brain and Spine Institute, Paris, France |
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MRI of the thoracic spinal cord (t-spine) is challenging especially due to motion, flow, and susceptibility artifacts. Improving the image quality and resolution in t-spine has the potential to improve visualization of anatomy, as well as lesions in neurodegenerative diseases such as multiple sclerosis (MS). Towards this end, we have developed high-resolution t-spine imaging techniques at 7T with a custom built RF transmit-receive coil and navigator based frequency correction. |
| 4398 | Computer #59 |
Spinal Perimedullary Vein Enlargement Sign: An Added Value for the Differentiation between Intradural-Extramedullary and Intramedullary Tumors on MR Imaging |
1Shandong University, Jinan, China, People's Republic of, 2Shanghai, China, People's Republic of |
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Magnetic resonance imaging (MRI) is widely used to narrow the differential diagnosis in the preoperative study of spinal cord tumors. The use of a medium in MRI is preferred to improve visualization of tumor’s intrinsic characteristics and boundaries, and to identify reactive changes (such as cysts and dilated veins) in adjacent tissues. Most times, it is easy to determine whether a lesion arises from the spinal cord itself or from the IDEM space according to common MRI findings, however, at other times, this might be difficult. There have been reported cases of schwannoma located at IDEM space misdiagnosed with IMT. Thus, radiologists must discern the characteristic imaging features of IDEMs to distinguish them from IMTs. The presence of vein enlargement is often a sign in some cases of intradural spinal tumors , most of which are extramedullary. A perimedullary vein enlargement sign around an intradural spinal tumor (without dilated veins in the tumor)has not been reported, which might be an imaging mark to differentiate IDEMTs from IMTs.The purpose of this study was to determine the added value of the perimedullary spinal vein enlargement sign on MRI in helping to distinguish IDEMTs from IMTs. |
| 4399 | Computer #60 |
Comparison of 3D FSE Cube and 3D Fiesta-c sequences for image contrasts of the tissues on T2-weighted images in cervical spine MRI |
1Division of Radiology, Seirei Sakura Citizen Hospital, Sakura, Japan, 2Department of Radiology, Toho University Sakura Medical Center, Sakura, Japan |
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Currently, various 3D MR sequences such as 3D FSE, GRE, and steady-state sequences have been developed and used to obtain MR images of submillimeter thicknesses in the spine. However, the question,“which 3D sequence has a better image contrast of the tissues in spinal MRI?”, has come up. Therefore, we examined optimal imaging parameters of variable refocus flip angle 3D FSE (Cube) and 3D Fiesta-c sequences for T2-weighted images in cervical spine MRI and compared the two different 3D sequences for better image contrasts of the tissues on T2-weighted images in cervical spine MRI. In conclusion, 3D FSE Cube T2-weighted images has excellent image contrasts between the spinal cord versus other tissues except cerebrospinal fluid, vertebral body, and subcutaneous fat in the cervical spine compared to 3D Fiesta-c T2-weighted images. Therefore, 3D FSE Cube sequence is believed to be more appropriate for T2-weighted images in cervical spine MRI compared to 3D Fiesta-c sequence. |
| 4400 | Computer #61 |
fMRI of lumbar spinal cord during electrical stimulation in diabetic patients |
1The 2nd Affilited Hosptial of Shantou Universtiy Medical College, Shantou, China, People's Republic of |
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Diabetic peripheral neuropathy (DPN) is one of the main complications of long-term diabetes and the incidence is 60% to 90%. However, there is no objective noninvasive method to detect the degree of damage of DPN and its pathogenesis remains unknown. Functional magnetic resonance imaging (fMRI) has the advantages of high spatial and temporal resolution, which had been used to detect neuron activity. In this study, the activation in the lumbar spinal cord of by electric stimulation were detected. Elevated activation percentage changes of DPN were found and the activation changes have the correlated relatioship with blood biochemical indexes such as glucose, the total cholesterol and haemoglobin A1c. |
| 4401 | Computer #62 |
The feasibility study of imaging lumbosacral spinal nerve roots by IDEAL sequence at 3.0T MR |
1Radiology Department, The Second Affiliated Hospital of Anhui Medical University, HeFei, China, People's Republic of, 2Department of CT &MRI, Air Force General Hospital, Beijing, China, People's Republic of, 3GE Healthcare, MR Research China, Beijing, Beijing, China, People's Republic of |
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The IDEAL acquisition can generate a water, fat, in-phase and out-phase data sets for clear tissue differentiation in a single sequence. It offers a great opportunity for imaging the nerve root compression. In this work, we demonstrated the feasibility of IDEAL sequence to image the anatomic structure and the whole contort of the lumbosacral nerve roots as well as the microstructural of lumbosacral nerve on the canals of lumbar spinal nerves is possible.IDEAL imaging on lumbosacral nerve roots can be valuable for clinical diagnosis to estimate the nerve compression, and provide detailed information for the right treatment at early-stage. |
| 4402 | Computer #63 |
Reduced Field-of-View Diffusion-Weighted Imaging of the Lumbosacral Enlargement: A Pilot In Vivo study of the healthy spinal cord using a clinical 3T MR system |
1NMR Research Unit, Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, University College London, London, United Kingdom, 2Translational Imaging Group, Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 3NIHR Biomedical Research Centre, UCL-UCLH, London, United Kingdom, 4Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy |
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The use of imaging methods to study the lower spinal cord has been hindered by a number of technical challenges; hence the relative contribution of pathology affecting the lower spinal cord to the observed clinical symptoms remains largely unexplored. In this pilot study, we investigate the feasibility of obtaining tissue-specific (grey matter and white matter) diffusion tensor imaging metrics within the lumbosacral enlargement in vivo in healthy volunteers using reduced field-of-view echo planar imaging on a clinical 3T MRI system. Preliminary results show that such measures may be obtained reliably and within clinically acceptable scan times. |
| 4403 | Computer #64 |
Right-handedness is associated with myelination asymmetry of the motor tracts in the human spinal cord |
1CRMBM UMR 7339, Aix-Marseille Université, CNRS, Marseille, France, 2LBA UMR T 24, Aix-Marseille Université, IFSTTAR, Marseille, France, 3CEMEREM, AP-HM, Pôle d'imagerie médicale, Marseille, France, 4iLab-Spine international associate laboratory, Marseille/Montréal, France |
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Handedness is known to influence brain structure. However, no evidences of such influence in the spinal cord (SC) exist. Hence, we propose to use multi-parametric MRI (DTI and inhomogeneous MT, both sensible to microstructural properties), combined with atlas-based analysis in specific fascicles, to assess the influence of handedness on the SC structure. Results demonstrated that right-handers presented higher ihMTR/MTR values in the right motor tracts, suggesting an asymmetric myelination while left-handers did not present differences between left and right regions. This is consistent with brain findings suggesting that right-handedness is associated with higher structural asymmetry in the central nervous system. |
| 4404 | Computer #65 |
Ultra-high-resolution postmortem imaging of marmoset EAE spinal cords |
1NINDS, NIH, Bethesda, MD, United States, 2INSERM U1127/CNRS UMR7225, CENIR, Brain and Spine Institute, Paris, France |
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Multiple sclerosis (MS) is a demyelinating disease that affects the entire central nervous system, with more than 90% of patients showing focal or diffuse abnormalities in the spinal cord (SC). Experimental autoimmune encephalomyelitis (EAE) in marmosets is an attractive animal model of MS due to its radiological presentation with brain lesions that mimic MS1. However, spinal cord lesions in marmoset EAE have not yet been well characterized. The proposed methodology allows high-quality, high-resolution imaging of SC lesions in autopsied marmosets with EAE. The artifact-free images allowed accurate detection of focal and confluent rim lesions along the edges of the SC. |
| 4405 | Computer #66 |
Multiband Excitation Enables Diffusion Tensor Imaging of Brain Stem and Cervical Spinal Cord in Clinically Feasible Scan Times at 3T |
1Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 2Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 3Philips Healthcare, Cleveland, OH, United States, 4Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States |
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Multiband excitation with diffusion tensor imaging (DTI) was implemented at 3T to enable characterization of the cervical spinal cord and brainstem in a clinically feasible scan time. The efficiency of the multiband acquisition (9 minutes) was compared to a standard acquisition (18 minutes), which included all of the same parameters except no multiband was applied. Results with multiband generated high-resolution images with similar SNR to the standard (whole cord: multiband – 6.60, no multiband – 6.14). Additionally, DTI measurements from the multiband acquisition were in good agreement to the standard, yielding a percent difference of less than 3% for the cervical spine. |
| 4406 | Computer #67 |
Diffusion basis spectrum imaging (DBSI) reveals axon loss on spinal cord in RRMS and NMO |
1Radiology, Washington University in St. Louis, St. Louis, MO, United States, 2Neurology, Washington University in St. Louis, St. Louis, MO, United States |
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DTI failed to detect the extent of axonal loss which plays a significant role in irreversible neurological impairments in MS and NMO patients. Our results suggest diffusion basis spectrum imaging (DBSI) may serve as a useful method to quantify the extent of axonal loss and confounding pathologies in RRMS and NMO. |
| 4407 | Computer #68 |
Correlation of DTI Metrics to Spinal Cord Cross Sectional Area in Pediatric Subjects with Spinal Cord Injury |
1Temple University, Philadelphia, PA, United States, 2Thomas Jefferson University, Philadelphia, PA, United States, 3University of Maryland, College Park, MD, United States, 4National Institutes of Health, Bethesda, MD, United States |
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As more advanced imaging techniques are used for the spinal cord (such as DTI) it is important to examine potential relationships to other injury biomarkers. This study was to examine correlations between DTI metrics and spinal cord cross sectional area in pediatric subjects with spinal cord injury. Cord cross section data was acquired using a recently developed technique for semi-automated spinal cord segmentation and measurement of spinal cord cross sectional area. Fractional anisotropy was found to be strongly significantly correlated with spinal cord cross sectional area in the injured subjects. |
| 4408 | Computer #69 |
A Simple and Fast Approach for Spinal Cord Imaging at 3T with High In-Plane Resolution and Good Contrast |
1Dept. of Radiology, Radiological Physics, University of Basel Hospital, Basel, Switzerland |
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For fast spinal cord images of high in-plane resolution and estimable contrast, an image combination of different inversion recovery (IR) prepared balanced steady state free precession (bSSFP) images acquired by a Modified Look Locker IR (MOLLI) sequence with fixed RR-intervals is suggested. The strength of the approach lies in its simplicity and that for short acquisition times of currently about 2mins per slice already a good contrast can be achieved at the high in-plane resolution of 0.4mm. |
| 4409 | Computer #70 |
Multisite feasibility study of spinal cord gray matter and total cord areas measurements on 2D Phase Sensitive Inversion Recovery images |
1Neurology, University of California San Francisco, San Francisco, CA, United States, 2Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 3Neurology, University Hospital Basel, University of Basel, Basel, Switzerland, 4Siemens Healthcare USA, San Francisco, CA, United States, 5Neuroscience Imaging Center, University of California San Francisco, San Francisco, CA, United States |
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The goal of the present work was to test the reliability of the C2-C3 spinal cord gray matter and total cord areas measurements performed using a 2D-PSIR sequence. Nine healthy subjects were scanned twice with repositioning in between the scans (test/retest) on three different 3T scanners with different hardware. On the phase sensitive-reconstructed images, total cord area was measured in a semi-automated way and gray matter area was estimated by using an automatic segmentation method. Evaluations of contrast to noise ratio, intra-scanner and inter-scanner reliability suggest that multicenter studies using a 2D-PSIR sequence are feasible. |
| 4410 | Computer #71 |
Automatic Gray Matter Segmentation of the Spinal Cord in 2D Phase-Sensitive Inversion Recovery Images |
1UCSF, San Francisco, CA, United States |
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This study demonstrates the accuracy and reliability of a new method for automatic segmentation of spinal cord gray matter in 2D PSIR images at 3T of the C2-C3 spinal cord level in healthy controls. This method deforms an initial contour, based on registration from a template, using an active contours algorithm to ultimately obtain the final gray matter segmentation. When comparing the automatic segmentations with manual segmentations in 12 subjects, the Dice coefficients ranged from .82 to .93, with an average of .88. In 8 additional subjects that were scanned twice, the percent changes ranged from 1% to 6%. |
| 4411 | Computer #72 |
Towards Tissue Characterization of the Spinal Cord: High-Resolution T1 Relaxometry with Precise B1+-Mapping of the Spinal Cord at 3T |
1Dept. of Radiology, Radiological Physics, University of Basel Hospital, Basel, Switzerland |
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A high-resolution T1 mapping protocol for the spinal cord (SC) based on ultra-fast RF spoiled gradient echo sequences with initial precise B1-Tx mapping was developed. The measured T1 values for white matter (WM-SC) of 976ms and for gray matter (GM-SC) of 1154ms deviate notably from the corresponding T1 values found for the human cerebellum at 3T. This finding may partially explain the relatively low contrast between GM-SC and WM-SC frequently observed in SC imaging. Furthermore, the knowledge of these precise T1 values will allow to set up dedicated SC imaging protocols with an optimized GM-SC/WM-SC contrast in the future. |
| Exhibition Hall | Thursday, May 12, 2016: 13:30 - 14:30 |
| 4412 | Computer #73 |
Improving the Quality of Neonatal Brain Structural MRI with Shorter Acquisition Train Length |
1Center for Perinatal Research, Nationwide Children’s Hospital, Columbus, OH, United States, 2The Ohio State Univeristy, Columbus, OH, United States, 3Radiology, Nationwide Children’s Hospital, Columbus, OH, United States, 4Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, United States |
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Three-dimensional (3D) T1-weighted sequences such as MP-RAGE are invaluable for evaluation of neonatal and infant brain injury/development. Sequence optimization for neonates has been historically challenging because neonatal brains exhibit reversed white matter–gray matter (WM-GM) contrast on T1-weighted scans, and the contrast is much lower than that of adult brains. In this study, we show in preterm neonates that shortening the acquisition train length of the MP-RAGE sequence significantly improved SNR and CNR efficiencies. The proposed optimization methodology can be easily extended to other populations (e.g. term infants, adults and elders), and different organs, field strengths and MR sequences. |
| 4413 | Computer #74 |
HASTE imaging with EPI volumetric navigators for real-time fetal head motion detection |
1Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA, United States, 2Radiology, Harvard Medical School, Boston, MA, United States, 3Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 4Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 5Siemens Medical Solutions USA Inc, Charlestown, MA, United States, 6Harvard-MIT Health Sciences and Technology, Institute of Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, United States |
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Although heavily used in clinical fetal imaging due to its encoding efficiency, the image quality of T2-weighted singe-shot fast-spin-echo (ss-FSE, or HASTE) acquisitions is often compromised by fetal head motion. We have implemented and tested an enhanced version of the HASTE acquisition scheme that includes EPI-based volumetric navigators (EPI-vNavs) played each TR, enabling detection and estimation of fetal head motion along six degrees of freedom in real time, while maintaining equivalent T2 contrast in the fetal head compared to the original HASTE acquisition. |
| 4414 | Computer #75 |
Free-breathing T1-weigthed gradient-echo imaging for fetus brain |
1Department of Radiology, Xijing Hospital, xi'an, China, People's Republic of |
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Magnetic resonance (MR) imaging appears to be increasing used for the diagnosis of abnormalities in fetuses because of the absence of ionizing radiation and superior contrast of soft tissues. However, the T1-weighted 3D MR imaging for fetus remains very challenging due to the respiratory motion of the mother and the movement of the fetus. In this study, we evaluated the feasibility of a free-breathing 3D T1-weighted gradient-echo imaging with radial data sampling for fetus imaging, and compared with a standard breath-hold imaging with Cartesian k-space acquisition |
| 4415 | Computer #76 |
HARDI Acquisition in Neonates and Children using Modular Multiband Multi-shell Sequence |
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2University of Pittsburgh, Pittsburgh, PA, United States, 3Children's Hospital of Pittsburgh, Pittsburgh, PA, United States |
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High angular-resolution diffusion imaging (HARDI) is the best imaging technique to distinguish crossing fibers and high turning angle neuronal tracts, which is critical for identifying and characterizing the microstructural changes in neuro pathology and traumatic brain injury. Its main disadvantage has been the lengthy scan time needed to acquire analyzable images – a challenge especially in children and neonates who do not tolerate long scanning sessions. This study presents the preliminary fiber tractography of healthy neonatal and pediatric subjects acquired using multiband multi-shell HARDI sequence within a practicable scan time without sacrificing image quality. |
| 4416 | Computer #77 |
Gender-specific attention system subnetwork vulnerability in prematurely born children |
1Division of Development and Growth. Department of Pediatrics, University Hospital of Geneva, Geneva, Switzerland, 2Signal Processing Laboratory 5, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 3Child Clinical Neuropsychology Unit, Department of Psychology, University of Geneva, Geneva, Switzerland, 4Research Unit, University Service of Child and Adolescent Psychiatry, Department of Psychiatry, University Hospital of Lausanne (CHUV), Lausanne, Switzerland, 5Department of Radiology and Medical Informatics, Faculty of Medicine, University of Geneva, Geneva, Switzerland, 6Department of Radiology, University Hospital Center (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland |
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Within preterm-born children, being born male and at a lower gestational age have both been associated with a heightened risk for developmental difficulties. However, in this population little is known about the combined effect and the influence of these risk factors on the structural networks subserving attention and executive. Using a diffusion-based brain connectome approach, in this work we analyze the effect of these two factors in the brain networks of school-age preterm born children and provide evidence of a gender-specific vulnerability in the executive attentional subnetwork. |
| 4417 | Computer #78 |
White Matter Structural Alternations in Children with HIV Infection and Exposure |
1MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, South Africa, 2Scientific and Statistical Computing Core, National Institutes of Health, Bethesda, MD, United States, 3African Institute for Mathematical Sciences, Muizenberg, South Africa, 4Children’s Infectious Diseases Clinical Research Unit, Department of Pediatrics and Child Health, Stellenbosch University, Cape Town, South Africa, 5Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States |
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In this work we examine WM alterations in HIV infected children at age 7 years and compare those who initiated ART before and after 12 weeks of age. |
| 4418 | Computer #79 |
Drum Training induces MR visible changes in the Cerebellum and Cortex |
1Department of Neuroimaging, King's College London, The Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom, 2School of Sport and Exercise, University of Gloucestershire, Chichester, United Kingdom, 3NatBrainLab, Department of Neuroimaging, King's College London, The Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom, 4Department of Sport and Exercise, University of Chichester, Chichester, United Kingdom, 5Centre for Digital Music, School of Electronic Engineering and Computer Science, Queen Mary University, London, United Kingdom |
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Cerebellar networks show long-term plasticity and motor training has been shown to change cerebellar microstructure and cortical thickness. We used a combination of neuroimaging measures to visualise plastic changes in drumming - a demanding multilimb training method: cerebellar lobular volume and shape analysis, cortical thickness and diffusion tensor imaging. Drum training reorganises and reshapes the posterior cerebellum, expanding to connected parietal and prefrontal cortical structures through the inferior cerebellar white matter pathway. Thus, it may offer a novel method for cerebellar and cortical plasticity, relevant as an intervention method for psychiatric disorders connected to cerebellar dysfunction, including autism spectrum disorder. |
| 4419 | Computer #80 |
Absolute metabolite concentration of Creatine in the deep gray matter measured using short echo 1H-MRS predict long-term prognosis of neonatal hypoxic-ischemic encephalopathy as excellent as NAA concentration |
1Radiology, Kanagawa Children's Medical Center, Yokohama, Japan, 2Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan, 3Neonatology, Kanagawa Children's Medical Center, Yokohama, Japan, 4Social Medicine, National Research Institute for Child Health and Development, Tokyo, Japan |
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Absolute metabolite concentrations of N-acethylaspartate (NAA), Choline(Cho) and Creatine(Cr) in the deep gray matter of 44 near term neonates with hypoxic-ischemic encephalopathy (HIE), measured using PRESS method short echo 1H-MRS within 2 weeks after birth, showed excellent prognostic values (AUC; NAA: 0.98, Cho: 0.96, Cr: 0.99) with the adverse outcomes having significantly lower measurements compared to those with favorable outcomes, while Lactate was less efficient (AUC 0.74). Moreover NAA and Cr concentrations measured at 24-96 hours revealed perfect prognostic values (AUC 1.00). Early measurement of absolute Cr and NAA concentrations can be excellent biomarkers of infants suffered with neonatal HIE. |
| 4420 | Computer #81 |
Iron deposition in the globus pallidus of healthy youth |
1University of Pennsylvania, Philadelphia, PA, United States |
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R2*, the transverse relaxation rate was used to measure iron deposition in the globus pallidus of 815 youth and young adults between the ages of 8 and 22. Significant iron deposition occurs in the globus pallidus between the ages of 8 and 22 in accordance with previously described models of iron deposition in the brain throughout the lifespan. Among adolescents (age 12-16) females had lower iron deposition in the globus pallidus (p < 0.001) as compared to males, this may be related to adolescent females being especially susceptible to dietary iron deficiency because of poor dietary intake in conjunction with high iron requirements related to rapid growth and menstrual blood loss. |
| 4421 | Computer #82 |
Parcellation of neonatal brain MRI into 107 regions using atlas propagation through intermediate time points in childhood. |
1MRC Centre for Reproductive Health, University of Edinburgh, Edinburgh, United Kingdom, 2Department of Radiology, Royal Hospital for Sick Children, Edinburgh, United Kingdom, 3Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom, 4Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, United Kingdom |
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We created a neonatal brain atlas of healthy subjects that can be applied to multi-modal MRI data. Structural and diffusion 3T MRI scans were acquired after birth from 25 neonates born at term. The SRI24/TZO atlas was propagated to the neonatal data using temporal registration via childhood templates (NIHPD), with the final atlas (the Edinburgh Neonatal Atlas, ENA25) constructed using iterative averaging of T1-weighted volumes. The computed transformations were applied to T2-weighted data, diffusion maps and tissue probability maps to provide a multi-modal atlas with 107 anatomical regions; and we have generated a symmetric version to facilitate studies of laterality. |
| 4422 | Computer #83 |
Assessing the effects of pediatric subject motion on T2 relaxation under spin tagging (TRUST) cerebral oxygenation measurements using volume navigators (vNavs) |
1Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, 2Martinos Center for Biomedical Imaging, MGH/Harvard Medical School, Boston, MA, United States, 3Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 4Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Boston, MA, United States, 5Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, 6Institute for Medical Engineering and Science, Cambridge, MA, United States |
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When using the T2-relaxation under spin tagging (TRUST) technique on non-compliant subjects, motion has an unknown effect on estimations of cerebral oxygenation that are derived from an empirical mapping between T2 and blood oxygen saturation. Incorporating low resolution 3D-EPI volume navigators into the TRUST pulse sequence permits independent measurements of motion during scanning. We show that for static scans vNav modules have only small effects on resulting venous blood T2 estimates, that poor exponential goodness of fit is not a sufficient indicator of motion, and that T2 is biased upwards with increasing motion. |
| 4423 | Computer #84 |
Congenital sensorineural hearing loss affects the development of corpus callosum |
1Center for MRI Research, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China, People's Republic of, 2Beijing cancer hospital, Beijing, China, People's Republic of, 3Tianjing First Central Hospital, Tianjing, China, People's Republic of, 4Aerospace Central Hospital, Beijing, China, People's Republic of |
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Congenital sensorineural hearing loss (CSHL) is a common disease in newborns, which can affect the development of corpus callosum (CC). In this study, a novel method of CC thickness analysis was employed to compare the CC difference between deaf and control groups. The results indicate that after 24 months deaf group has thinner CC thickness in the anterior splenium of CC compared to control group, which means the development of deaf anterior splenium is slowed down. Our study suggests that 12~24 month old is the best time period for CSHL treatment and intervention. |
| 4424 | Computer #85 |
Age-specific gray and white matter DTI atlas for human brain at 33 and 36 postmenstrual weeks |
1Department of Radiology, Children’s Hospital of Philadelphia, Philadelphia, PA, United States, 2Research Center for Sectional and Imaging Anatomy, Shandong University School of Medicine, Jinan, China, People's Republic of, 3Department of Radiology, Beijing Children’s Hospital Affiliated to Capital Medical University, Beijing, China, People's Republic of, 4Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, 5Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, 6Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States |
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The large brain morphological differences of the preterm brain at 33 or 36 postmenstrual week (PMW) to that at 40 PMW makes it necessary to establish age-specific atlases for preterm brains. In this study, with diffusion MRI (dMRI) data acquisition of 82 preterm and term normal neonates, we aimed to establish a comprehensive digital atlas including labeling of gray and white matter for preterm brains at 33 and 36 PMW. We demonstrated these atlases and showed the differences of the major neural structures including ganglionic eminence and uncinate fasciculus by comparison to JHU-neonate-SS atlas for brains at around 40PMW. |
| 4425 | Computer #86 |
Variable Refocusing Flip Angle Single Shot Imaging For Anesthesia-Free Brain MRI |
1Stanford University, Stanford, CA, United States |
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Conventional single shot fast spin echo (SSFSE) and variable refocusing flip angle SSFSE (vrfSSFSE) were compared for fast sedation-free pediatric brain MRI (N=33). Two neuroradiologists independently and blindly evaluated SSFSE and vrfSSFSE images for motion, perceived resolution (sharpness), contrast and lesion conspicuity on a five-point scale. vrfSSFSE gave less motion and misregistration artefacts than conventional SSFSE, due to the shorter scan duration. As for the other image quality metrics, vrfSSFSE was found to be either comparable or superior to conventional SSFSE. |
| 4426 | Computer #87 |
Distortion correction of fetal EPI using registration of orthogonal stacks with Laplacian constraint |
1King's College London, London, United Kingdom, 2Instituto de Biofisica e Engenharia Biomedica, Faculdade de Ciencias, Universidade de Lisboa, Lisbon, Portugal |
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We present a novel method for correction of geometric distortions induced by static B0 field in fetal EPI. The method estimates distortion by including a distortion-correction step in the slice to volume reconstruction of orthogonal EPI stacks with orthogonal phase encoding directions, in the form of non-rigid registration with a Laplacian constraint. We show that the proposed method achieves better consistency with reconstructed ssFSE volumes than EPI volumes constructed from data corrected by B0 field map. The registration-based distortion correction is thus a viable alternative to acquisition of B0 field map. |
| 4427 | Computer #88 |
Age-related white matter changes on phase difference enhanced imaging in children |
1Radiology, Tokai University School of Medicine, Isehara, Japan, 2Medical Physics in Advanced Biomedical Sciences, Kumamoto University, Kumamoto, Japan, 3Biomedical Engineering, Tokai University School of Engineering, Isehara, Japan |
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Recent reports suggest that phase shift in the white matter may be related to myelin content. We assessed the age-related phase changes of the white matter in small children (age range, 0‒6 years) on phase difference enhanced imaging (PADRE). PADRE showed progression of the phase changes in the white matter along with age, particularly in the pyramidal tract and subcortical region in Rolandic are. Whereas, less phase changes were noted in the subcortical white matter in the temporal lobe. PADRE showed age-related white matter phase shift, suggesting progression of myelination and myelin content. |
| 4428 | Computer #89 |
A simple method for myelin mapping using T1-weighted, T2-weighted and PD-weighted images |
1Biomedical Engineering, King's College London, London, United Kingdom, 2Centre for the Developing Brain, King's College London, London, United Kingdom, 3Perinatal Imaging and Health, King's College London, London, United Kingdom |
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Myelin mapping is of great interest, particularly to study brain development. However, existing methods are time consuming and/or noisy. We propose a simple method to obtain semi-quantitative maps of myelin from routinely acquired T1-, T2- and proton density weighted images, by modelling the signal as a linear combination of non-exchanging tissue types: lipid, tissue water and free water. The method is calibrated empirically from the signal intensities in the data themselves. We show promising results in neonatal scans, showing the expected pattern of myelination in infants at term-equivalent age. |
| 4429 | Computer #90 |
Reduced GABA levels and altered sensory function in children with Autism Spectrum Disorder |
1Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States, 2F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 3Center for Autism and Related Disorders, Kennedy Krieger Institute, Baltimore, MD, United States, 4Psychiatry and behavioral sciences, Johns Hopkins University, Baltimore, MD, United States, 5Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada, 6Radiology, University of Calgary, Calgary, AB, Canada, 7Laboratory for Neurocognitive and Imaging Research, Kennedy Krieger Institute, Baltimore, MD, United States, 8Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 9Neurology, Johns Hopkins University, Baltimore, MD, United States |
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Children with Autism often show difficulties processing sensory stimuli, but the underpinnings are poorly understood. Multiple lines of evidence suggest that GABA, the main inhibitory neurotransmitter in the brain, plays a role in the pathophysiology of ASD. Here we show reduced GABA levels in children with ASD, which is associated with abnormal performance on vibrotactile tasks related to inhibition. We show that alterations in GABA can contribute to alterations in sensory processing in ASD. |
| 4430 | Computer #91 |
Microstructural organization of the language connectome in typically developing left-handed children: a DTI tractography study |
1Dept. Neurosciences, KU Leuven, Leuven, Belgium, 2Dept. Pediatrics, UZ Leuven, Leuven, Belgium, 3Dept. Translational MRI, KU Leuven, Leuven, Belgium |
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The main objective of this study was to investigate the relationship between the microstructural properties of language-related white matter (WM) tracts and hand preference in typically developing school-aged children. Our DTI tractography results provide evidence for a different structural connectivity pattern of the language connectome in left-handed children. Whereas right-handed children show a clear left-lateralized structural language network, our group of left-handed children seems to have a more bilateral organized language system. Those observed differences in WM microstructure and lateralization might reflect an interaction between handedness and the neural processing of language in children. |
| 4431 | Computer #92 |
Optimal Slice Planning of the Fetal Brain Using Interactive Real-Time MRI |
1MR Research Centre, Aarhus University Hospital, Skejby, Aarhus N, Denmark, 2Department of Procurement & Clinical Engineering, Region Midt, Aarhus N, Denmark, 3Department of Obstetrics and Gynecology, Aarhus University Hospital, Skejby, Aarhus N, Denmark, 4Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark, 5Department of Computer Science, Aarhus University, Aarhus N, Denmark |
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Diagnostic image quality of MRI can be hampered by fetal movements during data acquisition which may limit its diagnostic use (1;2). We propose an interactive real-time MRI technique which may serve as an alternative to traditional fetal MRI for anthropometrics or as a supplement for representation of fetal brain structures in cases in which fetal motion causes challenges in relation to obtaining optimal slice planes using conventional MRI techniques. |
| 4432 | Computer #93 |
A hybrid premature neonatal segmentation pipeline for clinical brain imaging acquired without dedicated neonatal coils. |
1Bioengineering, University of Washington, Seattle, WA, United States, 2Pediatrics, University of Washington, Seattle, WA, United States, 3Pediatrics, Bioengineering, Radiology, University of Washington, Seattle, WA, United States |
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Due to the difference in individual cases, larger multi-site studies of brain injury after premature birth may be needed, but dedicated neonatal imaging technology isn't always available. The use of older scanners with coils not specifically aimed at imaging neonatal brains introduces a severe intensity variation across the field of view, which can cause conventional image analysis pipelines to fail. A robust hybrid tissue segmentation pipeline was developed and shown to improve tissue segmentations of four test subjects with manual segmentations for reference. This enables automated and consistent analysis to better quantitatively study early human brain development. |
| 4433 | Computer #94 |
Utilization of Simultaneous Multi-slice Accelerated Turbo Spin Echo in Pediatric Epilepsy |
1Children MRI Centre, Royal Childrens Hospital, Parkville, Australia, 2Murdoch Childrens Research Institute, Parkville, Australia, 3Royal Childrens Hospital, Parkville, Australia, 4Siemens Healthcare, Bayswater, Australia, 5Centre for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 6Siemens Medical Solutions, Malvern, PA, United States |
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The objective of our prospective study was to examine the clinical utility of Simultaneous Multi-Slice(SMS) Accelerated TSE at 3T imaging paediatric patients who present with seizures.A randomly selected cohort of patients were enrolled in the protocol covering a broad spectrum of clinical entities. A direct comparison was undertaken with anatomically matched conventional TSE and SMS TSE acquisitions with matched in-plane and through plane resolution, echo train lengths and echo spacing. Analysis of the data confirmed that although there were minimal variations in the quantitative measures recorded both sequences provided images of consistent image quality and diagnostic confidence with a significant scan time reduction attributed to the SMS TSE acquisition. |
| 4434 | Computer #95 |
Amide proton transfer imaging of neonatal brain development and brain injury: a preliminary study |
1Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China, People's Republic of, 2Philips Healthcare, Beijing, China, Beijing, China, People's Republic of, 3Division of MR Research, Department of Radiology, Johns Hopkins University, Maryland, USA, Baltimore, MD, United States |
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Yang Zheng M.D. Department of Radiology, Shengjing Hospital of China Medical University, No. 36, Sanhao Street, Heping District, Shenyang 110004,PR China E-mail address: jingshenbing0702@gmail.com Tel.: +86 13889830846 |
| 4435 | Computer #96 |
Effects of pediatric HIV/antiretroviral therapy on basal ganglia metabolite-volume relationships |
1Department of Human Biology, University of Cape Town, Cape Town, South Africa, 2Department of Statistical Sciences, University of Cape Town, Cape Town, South Africa, 3Department of Paediatrics & Child Health, Stellenbosch University, Stellenbosch, South Africa, 4A.A. Martinos Centre for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 5Department of Radiology, Harvard Medical School, Boston, MA, United States |
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HIV is associated with structural deficits in the basal ganglia (BG). Volumes from structural MRI may relate to metabolic changes measurable with magnetic resonance spectroscopy. We investigated the relationship between BG NAA and Glutamate/Glutamine and caudate, putamen, nucleus accumbens and subcortical gray matter (GM) volumes in 7-year old HIV-infected children on antiretroviral therapy and uninfected controls. Higher NAA was associated with smaller accumbens and left putamen in all children. Higher Glutamate/Glutamine was associated with greater subcortical GM in controls, but not HIV-infected children. Relationships between brain metabolites and volumes add to the description of effects of HIV/ART on the BG. |
| Exhibition Hall | Thursday, May 12, 2016: 14:30 - 15:30 |
| 4436
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Computer #49 |
Mapping Glutamate Changes in the Brain: GluCEST as a Biomarker to Study Localized Glial Function Derangements |
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States |
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MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) causes selective dopaminergic death in the substantia nigra and striatum leading to dopamine loss in the basal ganglia. Here, we apply glutamate chemical exchange saturation transfer (GluCEST), a novel non-invasive MRI technique, to investigate glutamate changes in MPTP mouse model. The data suggests elevation in GluCEST contrast in striatum and motor cortex of MPTP treated mice. Immunostaining experiments showed elevation of glial markers in the striatum, which correlates with the GluCEST contrast. Also, motor function was found to be negatively correlated with GluCEST. |
| 4437
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Computer #50 |
Acute pressure changes in the brain are measurable with MR Elastography: Initial feasibility in an in vivo porcine model |
1Mayo Clinic, Rochester, MN, United States |
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Hydrocephalus is a common medical condition that results from obstruction to the flow of cerebral spinal fluid (CSF) or resorption of CSF. No non-invasive method offers direct measurement of intracranial pressure (ICP). Magnetic resonance elastography (MRE) is capable of non-invasively measuring brain tissue stiffness in-vivo, and may act as a surrogate to ICP. The objective of this study was to investigate the impact of ICP on brain stiffness using MRE in a porcine model. This study shows that MRE brain stiffness changes directly correspond to changes in ICP, motivating future investigation into shunt-therapy monitoring in a patient population. |
| 4438
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Computer #51 |
Long term high fat diet modifications of the neurochemical profile of the mouse hypothalamus |
1Laboratory for Functional and Metabolic Imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2Department of Radiology, University of Lausanne, Lausanne, Switzerland, 3Department of Radiology, University of Geneva, Geneva, Switzerland |
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Obesity is a complex disorder that leads to reduced life expectancy, with increased risk of heart disease, type-2 diabetes, high blood pressure and some type of cancers. To understand the mechanisms of obesity development, several animal models, such as high fat diet administered rodents, are being studied. We designed a longitudinal study to investigate the short and long term effects of high caloric diet intake in two populations of mice -high fat or regular fed- during 6 months, evaluating in vivo the changes in the neurochemical profile of the hypothalamus by 1H MRS. |
| 4439 | Computer #52 |
A 3D HIGH RESOLUTION MRI ATLAS OF THE SHEEP BRAIN |
1Laboratory of Reproductive Physiology and Behavior, INRA - Centre Val de Loire, Nouzilly, France |
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The sheep model was first used in the field of reproductive physiology in agronomy to improve milk and meat production, and then was brought into fundamental and preclinical neurosciences. Since a decade, MR studies performed on this model are increasingly reported. To play an important role in MR translational neuroscientific research, a brain template and an atlas are therefore necessary. Simultaneously, two MR templates were proposed in 2015. To complete the set of MR tools, we computed a high resolution 3D in-vivo sheep brain atlas including: i) gyri and sulci ii) inner structures iii) main external structures. |
| 4440 | Computer #53 |
TBM and DTI reveal structural changes by memantine treatment in YAC128 mouse model of Huntington disease |
1Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore, Singapore, 2Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, Singapore, Singapore, 3Department of Medicine, National University of Singapore, Singapore, Singapore |
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T2 weighted structural and diffusion MRI together with behavioral tests were conducted to evaluate the effects of memantine treatment in YAC128 mouse model of Huntington disease. In low-dose (2 mg/kg)-treated YAC128 mice, cognitive functions improved, and increased fractional anisotropy was found in major fiber tracts including the corpus callosum, anterior commissure, and internal capsule. No significant gray matter volume change was detected in treatment groups, though the relative caudate putamen volume showed increasing trend with dose. Our results suggest that low dose memantine treatment had protective effects on white matter in YAC128 mice. |
| 4441 | Computer #54 |
A step towards developing MR elastography and diffusion tensor imaging as complementary MR tools to improve the management of hydrocephalus. |
1Neuroscience Research Australia, Randwick, NSW, Australia, 2School of Medical Sciences, University of New South Wales, Kensington, NSW, Australia, 3Biological Resources Imaging Laboratory, University of New South Wales, Kensington, NSW, Australia, 4BHF Centre of Excellence, Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 5Prince of Wales Clinical School, University of New South Wales, Kensington, NSW, Australia, 6Department of Engineering, Faculty of Science, Macquarie University, North Ryde, NSW, Australia |
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Hydrocephalus is characterised by enlarged ventricles resulting in compression of surrounding tissues. Conventional imaging techniques depict ventricle size accurately. However, they are limited to detect changes in brain microstructure. The aim of this work was to quantify changes in brain mechanical and diffusion properties during the development of hydrocephalus in rats, using MR Elastography and Diffusion Tensor Imaging. Results showed that both techniques have the potential to be complementary imaging tools for tracking the effects of hydrocephalus on the tissue microstructure and provided new insights on how the brain changes during the course of the disease. |
| 4442 | Computer #55 |
Glymphatic clearance impaired in a mouse model of tauopathy: captured using contrast-enhanced MRI |
1Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom, 2Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom, 3Eli Lilly and Company, Windlesham, United Kingdom, 4Eli Lilly and Company, Indianapolis, IN, United States |
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The ‘glymphatic’ clearance system is a brain-wide pathway for removal of waste solutes from the brain. It has recently been implicated in Alzheimer’s disease (AD), due to discovery that both amyloid and tau, accumulations of which lead to AD development, can be cleared from the brain via this pathway. We therefore hypothesise that an impairment of ‘glymphatic’ clearance occurs in the initial stages of disease development, leading to accumulation of amyloid and tau in the brain. Here, we determine whether this is the case, by using dynamic contrast-enhanced MRI to quantify glymphatic clearance in the brain of a mouse model of AD. |
| 4443 | Computer #56 |
High Field MR Demonstrates Effect of Glucocorticoids in a Novel Murine Model of VEGF-Induced Vasogenic Brain Edema |
1Surgical Neurology Branch/NINDS, National Institutes of Health, Bethesda, MD, United States |
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The molecular mechanisms mediating the formation of peritumoral vasogenic brain edema (VBE) and its abrogation from glucocorticoid treatment is poorly understood. In order to study the molecular underpinnings and temporal evolution of these processes we successfully developed a murine model of VBE confirmed by high field MRI and histopathologic studies. Furthermore, we demonstrate a differential effect of systemic glucocorticoids on blood-brain-barrier breakdown and edema formation. This in-vivo model will allow for further investigation into the molecular mechanisms of VBE formation and potentially provide additional targets for its treatment. |
| 4444 | Computer #57 |
Gray Matter Atrophy in A Rat Model of Chronic Hypoperfusion and The Effects of Environmental Enrichment: A Voxel-based Morphometry Study |
1National Center of Magnetic Resonance in Wuhan, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China, People's Republic of |
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Permanent bilateral common carotid arteries occlusion (2VO) rat model can induce pathological changes in brain, do these changes induce MRI visible structural changes? The enriched environment, an useful paradigm of increasing brain structural plasticity, may have a structural effect on 2VO rat brain. In this study the structural changes of 2VO rat brain with and without enriched environment (EE) were studied by in vivo MRI. Our results showed that sensorimotor cortex, dorsolateral striatum, cingulate cortex and dentate gyrus represented significant atrophy after 2VO and EE effectively protected against the gray matter atrophy. |
| 4445 | Computer #58 |
Neuroprotective Effects of Acetyl-L-Carnitine on Neonatal Hypoxia-Ischemia Induced Brain Injury in Rats |
1Diagnostic Radiology & Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States, 2Core for Translational Research in Imaging, University of Maryland School of Medicine, Baltimore, MD, United States, 3Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, United States |
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Cerebral hypoxia ischemia (HI) is a primary cause of perinatal brain injury. Infants surviving HI face risk of abnormal neurodevelopment, motor and intellectual disability. Acetyl-L-carnitine (ALCAR) is neuroprotective while its efficacy in perinatal HI treatment has yet to be shown. To test the neuroprotective efficacy of ALCAR and potential sex differences, we performed in vivo MRI and behavioral tests in a rat model of neonatal HI. Results revealed that ALCAR is neuroprotective in both morphological and behavioral outcomes. Males exhibit more consistent HI-induced functional impairments. ALCAR was effective in ameliorating functional impairments in both males and females. |
| 4446 | Computer #59 |
Sensitivity and specificity of susceptibility weighted imaging to cerebral microbleeds: A radiologic-neuropathologic correlation study |
1Magnetic Resonance Innovations Inc., Detroit, MI, United States, 2Abbvie, North Chicago, IL, United States |
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This study uses cynomologus macaques, a non-human primate, as an animal model for cerebral microbleeds (CMBs). The intent is to leverage histological slices stained for iron detection against an MRI protocol with susceptibility weighted imaging (SWI) systematically collected over the course of several weeks. The radiologic-neuropathologic assessment of the CMBs was done separately on SWI, T2WI, T2*, SWI phase, and susceptibility weighted imaging and mapping (SWIM). SWIM was also used to quantify the iron content in the basal ganglia structures, such as the caudate nucleus. A quantified increase in CMBs and iron content was observed. |
| 4447 | Computer #60 |
Acute high altitude exposure induces ADC change in rat brain |
1NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences (INMAS), Delhi, India, 2Department of Biophysics, Panjab University, Chandigarh, India |
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High altitude hypoxia poses a serious threat to human health. In the present study, rat were exposed to acute simulated high altitude exposure which resulted in apparent diffusion coefficient changes in brain regions including corpus callosum and hippocampus. The study suggested the occurrence of vasogenic edema in corpus callosum and delayed cytotoxic edema in hippocampus region of brain due to acute high altitude exposure. This study has potential in setting new insights to address high altitude related health problems effectively. |
| 4448 | Computer #61 |
Identification of the nigrostriatal and pallidothalamic fiber tracts by high-resolution probabilistic diffusion tractography in Squirel monkey |
1Centre de NeuroImagerie de Recherche - CENIR, Paris, France, 2Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, France |
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This work present tractography of an ex vivo brain of a primate model. Parkinson's disease ralated tracts were clearly identified and can serve as biomarkers in our primate model. |
| 4449 | Computer #62 |
MR GluCEST Study of Neuroinflammation |
12nd Affilicated Hospital, Shantou University Medical College, Shantou, China, People's Republic of |
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Glutamate (Glu) plays a crucial role in the early stage of neuroinflammation, which requires early diagnosis and treatment. This study aimed to explore Glu concentration changes in rats brain abscess model and patients with neuroinflammation using chemical exchange saturation transfer (CEST) MRI. |
| 4450 | Computer #63 |
MR spectroscopy predicts injury in a variable rat model of epilepsy |
1Developmental Biology, University of Pittsburgh, Pittsburgh, PA, United States, 2Pittsburgh, PA, United States, 3New Haven, CT, United States, 4University of Pittsburgh, Pittsburgh, PA, United States |
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MR spectroscopy in a variable rat status epilepticus (kainate induced) model of epilepsy is shown to segregate between mildly and severely injured animals. As measured 3days after status epilepticus, animals with NAA/tCr values of less than 1.0 (kainate more injured, KMI) segregated with greater increases in Inositol/tCr, Glutamine/tCr and Lac/tCr, with these changes predicting the metabolic measured 3weeks after status. Although Inositol/tCr was elevated in the kainate less injured KLI group, the KLI group showed milder changes at 3days and at 3weeks. This metabolic classification was also sustained into histologic studies. |
| 4451 | Computer #64 |
Assessment of intrauterine growth restriction on pup rat brain by DTI and NODDI at 9.4T |
1Division of Child Growth & Development, Department of Pediatrics, University of Geneva, Geneva, Switzerland, 2Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3Inserm U1141 – DHU PROTECT, Robert Debré Hospital, Paris, France |
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Experimental studies of intrauterine growth restriction (IUGR) in the rat, induced by protein or caloric restriction, have shown to have extensive effects on brain development including white and grey matter structural changes [1]. The aim of this work was to establish offspring cerebral structural changes following low protein diet in rats during gestation by using DTI and NODDI. LPD microstructural consequences on pup rats at P10/P21 were characterized. At P10, structural changes were mainly found in the white matter whereas at P21 cortical structure was abnormally developed. DTI and NODDI give accurate probing of the cerebral impairment following IUGR. |
| 4452 | Computer #65 |
Probiotics as possible treatment in Chronic Liver Disease-induced Hepatic Encephalopathy, an in vivo longitudinal 1H MRS study in a rat model |
1Laboratory of Functional and Metabolic Imaging, Center for Biomedical Imaging, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland, Lausanne, Switzerland, 2Service of Biomedicine, University Hospital of Lausanne, Lausanne, Vaud, Switzerland, Lausanne, Switzerland, 3Center for Biomedical Imaging, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland, Lausanne, Switzerland, 4Laboratory of behavioral genetics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Vaud, Switzerland, Lausanne, Switzerland, 5Sapienza University of Rome, Department of Public Health and Infectious diseases, Section of Microbiology, Rome, Italy, Rome, Italy, 6Swiss Center for Liver Disease in Children, Department of Pediatrics, University Hospitals Geneva, Geneva, Switzerland, Geneva, Switzerland |
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We investigated potential therapeutic effect of probiotic treatment with anti-inflammatory proprieties (VSL#3) in a rat model of Chronic Liver Disease induced Hepatic Encephalopathy (HE). 1H MRS at 9.4T revealed significantly lower increase of glutamine (typical sign of HE) and better osmoregulation in the hippocampus together with overall better performance in behavioural tests in treated animals. These results are very promising. |
| 4453 | Computer #66 |
Monitoring Treatment Response to Gene Therapy in a Feline Model of Alpha-mannosidosis using 1H MRS |
1Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States, 2Center for Perinatal Research, The Research Institute, and Nationwide Children’s Hospital, Columbus, OH, United States, 3Abramson Research Center, Children’s Hospital of Philadelphia, Philadelphia, PA, United States, 4Department of Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom |
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To evaluate the potential of in vivo proton MR spectroscopy (1H MRS) in monitoring treatment response to adeno-associated viral (AAV) gene therapy to the cisterna-magna in a cat model of alpha-mannosidosis. Normal (n=3), untreated (n=3) and AAV-treated (n=3) cats underwent multivoxel 1H MRS. Significant elevations in resonances due to mannose-rich oligosaccharides (OG) and N-acetylated sugars (Glc-NAc) were observed in brain of untreated cats compared to normal controls. AAV treated cats demonstrated a decrease (normalization) in the OG and Glc-NAc resonances, which were not significantly different from untreated cats indicating some degree of positive response to this therapy. |
| 4454 | Computer #67 |
Prenatal exposure to common insecticide Malathion selectively alters micro-structural architecture in male guinea pigs |
1Radiology, University of Maryland School of Medicine, Baltimore, MD, United States, 2Core for Translational Research in Imaging @ Maryland, Baltimore, MD, United States, 3Department of Epidemiology & Public Health, University of Maryland School of Medicine, Baltimore, MD, United States |
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To test the hypothesis that prenatal exposure of guinea pigs to malathion, one of the few organophosphate insecticides that is still in residential use in the USA, disrupts axonal integrity. After the sub-acute maternal exposure to malathion, male offspring of exposed mothers had significantly decreased diffusion metrics and anisotropy in the corpus callosum. The findings reveal the lasting effect of prenatal exposure to malathion and the danger of mother to child transmission of malathion in the environment. |
| 4455 | Computer #68 |
Radiation induced sub-acute, early delayed and late delayed changes in hippocampus: A successive MRS, DTI and behavioral evaluation after whole body radiation |
1NMR Research Centre, INMAS, Delhi, India, 2Division of Radiation Biosciences, INMAS, Delhi, India |
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Nuclear accidents or terrorist activities may lead to moderate dose whole body radiation exposure to a mass population. Whole body radiation exposure may influence brain function but it has not been extensively studied. Present study was conducted on mice to look for whole body radiation induced delayed behavioural, metabolic and microstructural changes. The results illustrated changes in recognition memory, MRS and MD values till 8 months post-irradiation. At later time points (10 and 12 months post-irradiation), no profound effect of radiation exposure was observed which indicates that 5Gy whole body radiation dose exposure does not have late delayed radiation injury. |
| 4456
|
Computer #69 |
R1 Relaxation Mapping of Manganese Uptake and Wash-out in a Non-Human Primate Model of Chronic Mn Exposure |
1School of Health Sciences, Purdue University, West Lafayette, IN, United States, 2Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States, 3Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, United States, 4School of Health Sciences, Purdue University, West lafayette, IN, United States |
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High exposure to manganese (Mn) causes motor impairments resembling Parkinson’s disease. Using R1 mapping we investigated the dynamics of brain Mn accumulation during and after chronic manganese exposure in nonhuman primates. The R1 in whole brain displayed a significant increase after 27-41 wks of exposure. The visual cortex was found to have continuous Mn accumulation over exposure duration, while R1 of substantia nigra was decrease at 66-81 wks. Some select brain areas still show hyperintensities ten months after cessation of exposure. Understanding the regional uptake and retention may help elucidating the relation of Mn exposure to neurological symptoms. |
| 4457 | Computer #70 |
Follow-up analyses on the effects of long-term use of high fat diet on hippocampal volumes and hippocampal metabolite concentrations in Wistar rats: a voxel based morphology and 1H MRS approach |
1Nencki Institute for Experimenal Biology, Warsaw, Poland, 2Warsaw University of Technology, Warsaw, Poland, 3Neuroanatomy, Jagiellonian University, Krakow, Poland, 4CNS Lab, Military Institute for Aviation Medicine, Warsaw, Poland |
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Our study of long-term use of high fat diet inducing mild ketonemia in Wistar rats showed improvements in learning and memory, as well as larger hippocampi and higher concentrations of tNAA (marker of neuronal viability), tCho (involved in metabolite turnover), and tCr (involved in cell energetics). Here, we applied voxel based morphometry (VBM) for structural images and used TARQUIN for 1H MRS data obtained at 7T. Results of VBM and TARQUIN provided results consistent with previous analyses. However, the use of a literature-based template lead to tissue contractions not detectable with study specific template. |
| 4458 | Computer #71 |
Feasibility of 50μm in vivo MR microscopy (μMRI) of mouse brain at 9.4 Tesla |
1Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States, 2MRI Molecular and Translational Research Center, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States, 3Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, The State University of New York at Buffalo, Buffalo, NY, United States |
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The technique of MR microscopy (μMRI) has evolved into an important tool for morphologic phenotyping and computational neuroanatomy research. However, due to the inherent challenges of mouse imaging, μMRI of mouse brain has so far mostly been limited to post mortem tissue, often relying on perfusion with a mixture of saline and a T1-shortening constant agent, which increases the MRI sampling efficiency. In this work, we demonstrate the feasibility of in vivo μMRI of mouse brain at 9.4 Tesla with a resolution of 50μm using a cryogenic brain coil and an optimized imaging sequence. |
| 4459 | Computer #72 |
Effect of dystrophin levels on brain volumes in Duchenne muscular dystrophy mouse models |
1Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Division of Image Processing, Dept. of Radiology, Leiden University Medical Center, Leiden, Netherlands, 3Percuros B.V., Enschede, Netherlands, 4Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands |
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Besides muscle, Duchenne muscular dystrophy also affects the brain, resulting in memory and behavior problems. The consequences of dystrophinopathy on gross macroscopic alterations in the mouse brain are unclear. We used a number of mouse models that express either 0%(mdx), 100%(Bl10-WT) or a low amount of dystrophin(mdx-Xist∆hs). We showed that while whole brain volume does not significantly differ between mdx and Bl10-WT mice, there are differences in volumes of individual brain substructures. These results are in line with human data, where brain volume was found to be reduced only in patients lacking both full-length dystrophin and the shorter isoform Dp140. |
| Exhibition Hall | Thursday, May 12, 2016: 14:30 - 15:30 |
| 4460 | Computer #25 |
Image Fusion of Ultrasound and Magnetic Resonance Imaging for Regional Anesthesia of the Hip: The Influence of MRI Scanning Position for Fusion Accuracy and Post Anesthesia Visualization of Anatomical Distribution of Local Anesthetics |
1Department of Anesthesiology, Aarhus University Hospital, Aarhus C, Denmark, 2Department of Radiology, Aarhus University Hospital, Aarhus C, Denmark, 3Hospital Pharmacy, Aarhus University Hospital, Aarhus C, Denmark, 4Electron Microscopy Lab and Stereology, Institute of Clinical Medicine, Aarhus University, Aarhus C, Denmark, 5Department of Orthopedic Surgery, Aarhus University Hospital, Aarhus C, Denmark |
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Ultrasound guided lumbar plexus blocks holds the potential for reducing anesthesia related complications in hip surgery in the elderly punctum. The ultrasound guidance is, however, imprecise and associated with epidural spread of local anesthetic due to limited visualization. It is the overall aim of this study to improve the quality of lumbar plexus blocks using Fusion imaging between MRI and ultrasound. Here we report preliminary results of the impact of different MR scanning positions for the accuracy of fusion imaging and report on the feasibility of using gadolinium doped anesthetics for studying the distribution of local anesthetic fluid using MRI. |
| 4461 | Computer #26 |
PET/MRI molecular imaging in sports medicine: Assessment of ACL graft viability with combined 18F-FDG and 3T MR imaging |
1Radiology, The Ohio State University, Columbus, OH, United States, 2Sports Medicine, The Ohio State University, Columbus, OH, United States, 3Sports Medicine, Pepperdine University, Malibu, CA, United States |
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Evaluation of ACL graft healing by combined PET/MR imaging is readily feasible but has limited quantitative accuracy with use of conventional PET systems. The application of next generation digital photon counting in PET improves the quantitative accuracy and precision of assessment of graft metabolic activity. This advanced imaging modality also holds potential for ultra-low dose PET imaging, enhancing the clinical utility of such a combined imaging approach for detailed assessment of ACL graft viability after reconstructive surgery. |
| 4462 | Computer #27 |
Diffusion Tensor Imaging of the brachial plexus as an aid to the diagnosis of inflammatory neuropathies: preliminary results. |
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Neurology, Academic Medical Center, Amsterdam, Netherlands, 3Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, Netherlands, 4Radiology, University Medical Center, Utrecht, Utrecht, Netherlands |
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Diagnosing -treatable- inflammatory neuropathies such as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN) can be challenging, especially differentiating MMN from -untreatable- focal spinal muscular atrophy (fSMA). One of the reasons is that conduction studies cannot evaluate reliably the proximal part of the brachial plexus. Therefore we investigated DTI of the brachial plexus in patients with CIDP, MMN, fSMA and healthy controls and found significant differences, indicating DTI might be a valuable diagnostic tool in the clinic. |
| 4463 | Computer #28 |
Comparison of vertebral bone marrow water ADC between young and old subjects: DW-MRS versus DWI |
1Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, 2Philips Research Laboratory, Hamburg, Germany, 3Neuroradiology, Technische Universität München, Munich, Germany |
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The apparent diffusion coefficient (ADC) of vertebral bone marrow has been proposed as a useful biomarker for differentiating between benign and malignant vertebral compression fractures and could potentially be beneficial for the understanding of physiological as well as pathological bone marrow changes. In this work we exploit the spectral resolution of diffusion weighted magnetic resonance spectroscopy (DW-MRS) to exclusively quantify the ADC of the bone marrow water component and compare it to DWI based measurements. The results of two age groups are compared. |
| 4464 | Computer #29 |
Using hyperpolarised 13C-MRS to explore murine skeletal muscle metabolism during exercise |
1Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom, 2PulseTeq Ltd, Surrey, United Kingdom, 3Queen's Medical Centre, University of Nottingham Medical School, Nottingham, United Kingdom, 4Physics, University of Oxford, Oxford, United Kingdom, 5Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom |
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Previous techniques used to determine the hierarchy of skeletal muscle metabolic fuel selection have been unable to directly describe the changes in cellular metabolic flux during exercise. The aim of this project was to develop a technique that allows the simultaneous assessment of metabolism and function in exercising skeletal muscle in real-time, in an intact mouse, using hyperpolarized [1-13C] pyruvate MRS. Our results demonstrate that the technique is sensitive enough to distinguish differences in metabolic flux between the resting and exercising states shown by a significant increase in 13C label incorporation into bicarbonate during exercise. |
| 4465 | Computer #30 |
Radiation-induced Early Temporal Changes of IVIM-based Diffusion and Perfusion Patterns of Bone Marrow Predict the Likelihood of Hematological Toxicity |
1The Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong, 2Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China, People's Republic of, 3Philips Healthcare, Hong Kong, Hong Kong |
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Intravoxel incoherent motion (IVIM) diffusion-weighted MRI offers the unique opportunity to simultaneously study the diffusion and perfusion changes in the bone marrow following whole-pelvis radiotherapy. We prospectively studied twenty-eight patients with cervical cancer who had paired IVIM MRI examinations before and at week-4 of treatment. We observed a distinctive positive trend of D (true diffusion coefficient) in patients who suffered hematological toxicity (HT), whilst D remained relatively stable in patients who did not suffer HT. In addition, f (perfusion fraction) increased following treatment, but this pattern was not unique to patients who suffered HT. |
| 4466 | Computer #31 |
The value of BOLD-MRI in early diagnosis of osteonecrosis of the femoral Head in patients with steroid treatment |
1Pingjin Hospital, Tianjin, China, People's Republic of, 2Northwestern Univerisity, Chicago, IL, United States, 3Philips Healthcare, Beijing, China, People's Republic of, 4MRI, PingJin Hospital, TianJin, China, People's Republic of |
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This study attempted to compare BOLD with conventional MRI sequences for determining the onset of osteonecrosis of the femoral head following steroid-related osteonecrosis. 112 patients who had received steroid treatment were scanned using conventional MRI and BOLD. The manifestation in BOLD-MRI is in accordance with the pathology of ONFH, which would allow early treatment of ONFH.
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| 4467 | Computer #32 |
Associations between quantitative MRI biomarkers in the lumbar spine and pain in chronic low back pain patients with disc degeneration |
1Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States, 2Center for Imaging Research, Medical College of Wisonsin, Milwaukee, WI, United States |
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Associations between quantitative MRI biomarkers in the lumbar spine and pain in chronic low back pain patients (CLBP) were studied. These biomarkers are currently being explored as quantitative metrics of disc degeneration. Since most CLBP cases are associated with pathologic disc degeneration processes, these biomarkers might provide clues about the actual source of pain. For analysis, the discs from each subject were pooled from the least to the most degenerated one using a semi-quantitative metric. Results showed that these biomarkers might aid in identifying the source of pain in CLBP patients. |
| 4468 | Computer #33 |
Quantitative assessment of lumbar disc degeneration by non-Gaussian diffusion-weighted imaging |
1Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan, 2Radiology, The University of Tokyo Hospital, Tokyo, Japan, 3Intelligent Systems, Graduate School of Information Sciences, Hiroshima City University, Hiroshima, Japan, 4Radiology, School of Medicine, Juntendo University, Tokyo, Japan |
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We performed q-space imaging(QSI) analyses for lumbar intervertebral discs(IVDs) in patients suffering from lower back pain with different stages of degeneration. We evaluated the correlation between the quantitative QSI measurements and the qualitative grading(Pfirrmann's scale) of disc degeneration. Our results suggest that the degenerative process of IVDs involves narrowing of the space for free water movement and a generally higher degree of microstructural complexity, in which we are unable to assess with conventional quantitative MR measurements. QSI may provide sensitive biomarkers for IVD degenerative microstructural changes and can potentially become a tool to allow characterization of various IVD pathologies. |
| 4469 | Computer #34 |
B1-insensitive high-resolution isotropic T2 mapping of the lumbar plexus with a T2-prepared 3D TSE |
1Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, 2Department of Neurosurgery, Technische Universität München, Munich, Germany, 3Philips Healthcare, Hamburg, Germany, 4Section of Neuroradiology, Technische Universität München, Munich, Germany, 5Zentralinstitut für Medizintechnik, Technische Universität München, Garching, Germany |
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T2 mapping is a great candidate for quantitatively assessing inflammatory changes in peripheral nerves. However, measuring T2 of the lumbar nerve roots is challenging because of the need for high isotropic resolution and the sensitivity of the region to transmit B1 inhomogeneities. The present work proposes a T2 preparation, based on a modified BIR-4 pulse, and combined with 3D TSE imaging for B1-insensitive high-resolution isotropic T2 mapping of the lumbar plexus. The feasibility of the method is shown in five healthy volunteers and a variation of T2 along the nerve root course is observed. |
| 4470 | Computer #35 |
Feasibility of brachial plexus assessment using 3D fat suppression T2-weighted Cube combined with double inversion recovery at 3T |
1Kurume University Hospital, Kurume, Japan, 2Saiseikai Futsukaichi Hospital, Chikushino, Japan, 3Mayo Clinic, Rochester, MN, United States |
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A high-resolution MR neurography using 3D fat suppression T2-weighted Cube combined with double inversion recovery (3D FS DIR Cube) was evaluated the feasibility of brachial plexus assessment. 15 normal volunteers were scanned 3D FS DIR Cube, 3D FS T2-weighted Cube (3D FS T2 Cube), and 2D IDEAL water on a 3T MRI scanner using a GEM NV coil. The 3D FS DIR Cube can provide excellent contrast between brachial plexus branch and surrounding tissues and increase the conspicuity of the nerves delineation with uniformed fat suppression and vessels signal suppression compared with 3D FS T2 Cube and 2D IDEAL water. |
| 4471 | Computer #36 |
Quantitative MR Imaging of Vertebral Disc and Bone Marrow in Chronic Kidney Disease: A Rat Model Study |
1Department and Institute of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, 2Division of Nephrology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, 3Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, 4Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, 5Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, 6Institute of BiomedicalSciences, Academic Sinica, Taipei, Taiwan, 7Department of Medical Research, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan |
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An animal study to investigate bone marrow changes in the lumbar spine by quantitative Magenetic Resonance Imaging |
| 4472 | Computer #37 |
Differentiation of spinal lesions using monoexponential, biexponential, and gamma distribution diffusion-weighted MR Imaging: Initial clinical results |
1Diagnostic Radiology, Hiroshima University Hospital, Hiroshima-shi, Japan, 2Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan |
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The purpose of this study was to quantitatively compare various diffusion parameters obtained from monoexponential, biexponential, and gamma distribution models in differentiating vertebral lesions in human subjects. All MR parameters, except for ADCfast and frac > 3, were significantly different between normal bone marrow and lesions. Water molecular diffusion parameters may provide additional information and improve the differentiation of spinal lesions compared with conventional diffusion parameters. This also refers to differentiation of malignant lesions from acute spinal fracture, in which both PG (D) calculated from gamma distribution model and perfusion fraction f of the biexponential model proved to be useful. |
| 4473 | Computer #38 |
Predictive patient assessment via T2 Mapping of the Lumbar Intervertebral Disc at 3T: Correlation of T2 values with clinical reports, morphological grading, RMDQ, and VAS at a 5-year follow-up in patients with low back pain |
1High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 2Department of Orthopaedics, Medical University of Vienna, Vienna, Austria, 3Department of Physical Medicine and Rehabilitation, Medical University of Vienna, Vienna, Austria |
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Anatomical determination of cause for low back pain often remains impossible in the majority of patients. This study examined the diagnostic and predictive capabilities of T2 values of the lumbar intervertebral discs (IVDs). Twenty-five symptomatic patients were examined via magnetic resonance imaging (MRI) at 3T at baseline and 5-year follow-up (FU). Combining radiological reports, morphological grading, region-of-interest (ROI) analysis and patient assessment (VAS and Roland-Morris-Disability-Questionnaire), significant predictive capabilities were identified. |
| 4474 | Computer #39 |
High-Resolution DWI of the Lumbar Plexus using B1-insensitive Velocity-Compensated Diffusion-Prepared 3D TSE |
1Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, 2Philips Healthcare, Hamburg, Germany, 3Zentralinstitut für Medizintechnik, Garching, Germany, 4Neuroradiology, Technische Universität München, Munich, Germany |
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Diffusion weighted imaging (DWI) can describe the microstructure of nerve fibers and is therefore a powerful tool in the study of neuropathic changes. Diffusion imaging in the body faces challenges with motion and B0 and B1 field effects. Particularly, imaging of nerves has resolution requirements that can limit the performance of the acquisition method. The lumbar plexus is a particularly difficult region to image due to the complexity of the nerve geometry there and its susceptibility to motion and field inhomogeneity. Therefore, careful considerations need to be taken in the design of a diffusion-prepared sequence for imaging the lumbar plexus. The present work proposes an adiabatic diffusion preparation module in combination with a 3D TSE readout to achieve high-resolution DWI of the lumbar plexus. |
| 4475 | Computer #40 |
Is intravoxel incoherent motion(IVIM) more helpful for differentiating benign from malignant vertebral bone marrow lesions comparing with the conventional DWI? |
1Department of medical radiology, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China, People's Republic of, 2Philips Healthcare, Guangzhou, China, People's Republic of |
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The aim of this study is to evaluate the value of intravoxel incoherent motion (IVIM) for the differentiation between benign and malignant vertebral bone marrow lesions. The results of our study show that IVIM is potentially a promising and valuable non-invasive method in differentiating the spinal benign and malignant diseases. |
| 4476 | Computer #41 |
Postoperative Spinal Imaging Metal Artefact Reduction Using Ultrashort Echo Time MRI: A Feasibility Study |
1Anatomy with Medical Imaging, University of Auckland, Auckland, New Zealand, 2Sydney, Australia, 3Auckland, New Zealand, 4Erlangen, Germany, 5University of Auckland, Auckland, New Zealand |
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Post-operative spine imaging with metal implants in situ are problematic because of the significant metal artefacts, in both CT due to beam hardening, and MRI fom signal loss. Ultrashort Echo Time (UTE) MRI has potential to significantly reduce metal artefacts because of its method of acquisition. Significant differences in metal artefacts between conventional MR and UTE are found in our study, imaging sheep spine with spinal fusion hardware in situ, with importnat clinical implications. |
| 4477 | Computer #42 |
Rapid and Distortion-Free Diffusion Tensor Imaging for Evaluation of Lumbar Nerve Roots Using Direct Coronal Single-Shot Turbo Spin-Echo Diffusion Sequence |
1Eastern Chiba Medical Center, Chiba, Japan, 2Chiba university graduate school of medicine, Chiba, Japan, 3Orthopaedic surgery, Eastern Chiba Medical Center, Chiba, Japan, 4Philips Electronics Japan, Tokyo, Japan |
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The purpose of this study was to visualize the lumbar nerve roots and to measure their FA values in healthy volunteers and in patients with neurological symptom of leg by using TSE-DTI. Tractography of the patients with symptomatic side of lumbar nerve roots indicated abnormalities such as narrowing, deformation, and disruption. The FA values of the symptomatic side of lumbar nerve roots were significantly lower than those of the asymptomatic side. TSE-DTI might more accurately evaluate compressed lumbar nerve roots compared to conventional EPI-DTI. Additionally, tractography of TSE-DTI enables visualization of abnormal nerve tracts and has a lower geometric distortion for diagnosing lumbar nerve compression than EPI-DTI. |
| 4478 | Computer #43 |
Quantification of vertebral bone marrow fat fraction using time-interleaved multi-echo gradient-echo water-fat MRI: preliminary experience in children |
1Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, 2Radiology, Phoenix Children's Hospital, Phoenix, AZ, United States, 3Philips Research, Hamburg, Germany, 4Section of Diagnostic and Interventional Neuroradiology, Technische Universität München, Munich, Germany, 5Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany |
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In this work, we describe our preliminary clinical experience using a previously reported time-interleaved six-echo gradient-echo (TIMGRE) acquisition for water-fat chemical-shift encoded MRI. The acquisition scheme involved two interleaves that acquired three echoes each with fly-back gradients. The pulse sequence was used to quantify vertebral bone marrow fat fraction in a pilot cohort of 12 pediatric patients (age range: 1-13 years) at 3T with 1.2-1.6 mm in-plane resolution and 1.2-3 mm slices. The knowledge on bone marrow fat fraction may provide insight into adverse effects on bone health later in life, given that there is clinical relevance of vertebral osteoporotic fractures in adults. |
| 4479 | Computer #44 |
UTE-T2* detects matrix changes in Achilles tendon after tendon allograft reconstruction for old Achilles tendon rupture and the correlation with clinical score: a preliminary study |
1Radiology, Huashan Hospital, Fudan University, Shanghai, China, People's Republic of, 2GE Healthcare, MR Research China, Shanghai, China, People's Republic of, 3Sports Medicine, Huashan Hospital, Fudan University, Shanghai, China, People's Republic of |
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This preliminary study used UTE-T2*, a novel quantitative technique with potential short-T2* relaxations that are not well captured by standard T2 mapping, to investigate T2* value in Achilles tendon (AT) after tendon allograft reconstruction (AT-R) and analyze the correlation between T2* value and AOFAS score. Six patients with AT-R and 6 sex, age, and BMI matched healthy controls were recruited for comparison. The results showed T2* values of middle (MID) and muscle-tendon junction (MTJ) regions in AT-R patients were statistically lower compared with the matched regions of controls and T2* value of MID region was negatively correlated with AOFAS score, which suggest T2* may be a promising marker for the detection of matrix changes in AT after AT-R. |
| 4480 | Computer #45 |
MR properties of cadaveric Achilles tendon enthesis with ultrashort echo time (UTE) sequences and correlate with biomechanics |
1Radiology Department, UCSD, San Diego, CA, United States, 2Radiology Department, The first affiliated hospital of Jinan University, Guangzhou, China, People's Republic of, 3The Scripps Research Institute, San Diego, CA, United States, 4GE Healthcare, san diego, CA, United States |
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Entheses are sites where tendons, ligaments, and joint capsules attach to bone. They may be fibrous or fibrocartilaginous. Entheses are adapted at both the macroscopic and the microscopic level to distribute stress over a wide area or volume. Entheses are very commonly involved in many diseases and the primary target of disease in the seronegative spondyloarthropathies .we aim to study the MR properties of cadaveric Achilles tendon enthesis using ultrashort echo time (UTE) sequences and correlate them with biomechanics. |
| 4481 | Computer #46 |
Accuracy evaluation of pulse sequences using inversion recovery pulse for T1 measurement. |
1Faculty of Health Sciences, Hokkaido University, Sapporo, Japan, 2Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand |
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It has been reported that T1 in skeletal muscles is proportional to the percentage of typeⅠfibers which would be a determinant for athletic performance. However, the precision of the measured T1 values is unclear due to various pulse sequences used for the measurement. In this study, we evaluated the reliability of T1 measured by pulse sequences with inversion recovery technique that is believed to be most accurate in T1 measurement. A value of goodness of fitting was employed for the quantitative evaluation of the obtained data. The influence of SNR on the T1 measurement was also examined. |
| 4482 | Computer #47 |
Depiction of deep fascia, epimysium and periosteum in 3 dimensional Ultrashort Echo Time MR Imaging (3D UTE) with histologic correlation in porcine model |
1Department of radiology, Inha University Hospital, Incheon, Korea, Republic of, 2Department of radiology, Soonchunhyang University Hospital, Bucheon, Korea, Republic of, 3GE Healthcare, San Diego, CA, United States, 4GE Healthcare, Seoul, Korea, Republic of |
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We evaluated the ability of depiction of deep fascia, epimysium and periosteum in 3 dimensional Ultrashort Echo Time MR Imaging (3D UTE) with histologic correlation in porcine model. In our study, the 3D UTE might depict deep fascia and periosteum as high signal intensities whereas the ability of visualization of epimysium was uncertain and high signal intensity of artifact remains in naked cortex without periosteum. |
| 4483 | Computer #48 |
The Advantages of Spectrally Calibrated 3D-MSI in Assessments of Symptomatic Spinal Fusion |
1Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 2Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States |
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Failed back surgery syndrome (FBSS) is a commonly encountered clinical condition for which the root cause often remains elusive after lengthy clinical assessment. While MRI provides great potential utility for uncovering the causes of failed back surgery syndrome, it also is confounded by metal-induced artifacts. This study explores the benefits of a prospectively calibrated 3D-MSI metal artifact reduction technique in assessing instrumented FBSS. Residual artifacts and clinical diagnostic impact were assessed on a cohort of symptomatic FBSS subjects. The results of the study indicate diagnostic advantages using calibrated 3D-MSI, even in the presence of lower-susceptibility titanium spinal hardware. |
| Exhibition Hall | Thursday, May 12, 2016: 14:30 - 15:30 |
| 4484 | Computer #49 |
Multiparametric quantitative MRI of cartilage composition and bone blood perfusion applied in a case-control study of patellofemoral pain. |
1Radiology, Erasmus University Medical Center, Rotterdam, Netherlands, 2General Practice, Erasmus University Medical Center, Rotterdam, Netherlands, 3Imaging Science and Technology, Delft University of Technology, Delft, Netherlands, 4Medical informatics, Erasmus University Medical Center, Rotterdam, Netherlands, 5Orthopedics, Erasmus University Medical Center, Rotterdam, Netherlands, 6Sports medicine, MC Haaglanden, Leidschendam, Netherlands |
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Diminished patellofemoral cartilage composition and vascular problems are potential pathogenic mechanisms in patellofemoral pain (PFP). These mechanisms can be studied in depth using advanced MRI techniques. We are the first to successfully apply a wide range of quantitative MRI techniques for cartilage composition and bone blood perfusion in a case-control study on PFP. The results show no significant differences in patellofemoral cartilage composition and patellar bone blood perfusion between PFP patients and healthy controls. |
| 4485 | Computer #50 |
MR texture analysis of subchondral bone in osteoarthritis |
1Radiology, Norfolk & Norwich University Hospital, Norwich, United Kingdom, 2Norwich Medical School, University of East Anglia, Norwich, United Kingdom, 3Trauma & Orthopaedics, Norfolk & Norwich University Hospital, Norwich, United Kingdom |
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Subchondral bone (SB) plays an important role in osteoarthritis (OA). Texture analysis (TA) is a method of quantifying changes in SB and may be a useful OA biomarker. The optimum MR method to allow TA of SB is unclear. We compared TA using two sequences which demonstrated promise in depicting SB structure in three groups of participants: normal controls (n=10), individuals with early OA (n=10) and individuals with advanced OA (n=10). TA using a 2D T1-weighted spin echo sequence demonstrated more significant differences in texture features between groups and improved classification accuracy compared to a 3D gradient echo sequence. |
| 4486 | Computer #51 |
T1 bi-component analysis across whole articular cartilage depth - from calcified cartilage to superficial cartilage |
1Radiology, University of California, San Diego, San Diego, CA, United States |
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Articular cartilage is a highly ordered tissue with an organized layered structure that can be functionally and structurally divided into the superficial, transitional, radial and the calcified cartilage. By exploiting intrinsic magnetic resonance (MR) properties of cartilage, current techniques allow for the non-invasive assessment of many of the structural components. More recently, ultrashort echo time (UTE) imaging sequences have been used to investigate the T2* relaxation times of bound and free water components in different layers of articular cartilage. However, the depth dependence of longitudinal relaxation times, or T1s are still unknown. In this study we aim to study the T1s of bound and free water in different layers of patella cartilage using UTE imaging sequences on a clinical 3T scanner. |
| 4487 | Computer #52 |
T1ρ imaging in hip cartilage: A comparative study in hips with and without cam type deformity |
1Medical Imaging, The Ottawa Hospital, Ottawa, ON, Canada, 2Radiology, University of Ottawa, Ottawa, ON, Canada, 3Orthopaedic Surgery, The Ottawa Hospital, Ottawa, ON, Canada, 4Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada |
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In this study we systematically investigated the analysis of hip cartilage T1ρ images in healthy as well as asymptomatic and symptomatic subjects with cam deformities. Hips with cam-type deformity showed a significant T1ρ prolongation compared to the healthy subjects indicating loss of proteoglycan in the lateral third of the anterosuperior quadrant. A significant correlation between entire hip cartilage T1ρ values and WOMAC subscore pain was found. The study shows that in the presence of a cam deformity, T1ρ has the ability to detect proteoglycan depletion, the earliest stage of cartilage degeneration, even before to symptoms occur. |
| 4488 | Computer #53 |
Buy One, Get Two for Free: Simultaneous Knee T2 Mapping and Morphological Analysis On Synthetic Images Using GRAPPATINI |
1Radiology, Lausanne University Hospital, Lausanne, Switzerland, 2Advanced Clinical Imaging Technology (HC CMEA SUI DI BM PI), Siemens Healthcare AG, Lausanne, Switzerland, 3LTS5, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland |
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A fast quantitative T2 mapping technique that additionally provides synthetic images for morphological assessment was validated by two experienced radiologists regarding (1) the T2 values through a phantom experiment and (2) the image quality through a quantitative and qualitative assessment for the knee joint in five healthy volunteers. |
| 4489 | Computer #54 |
Isotropic Three-Dimensional T2 Mapping of Knee Cartilage with T2-Prepared Segmented Gradient Echo at 3T |
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland |
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An isotropic three-dimensional T2 mapping technique with adiabatic T2 magnetization preparation for T2 relaxation time quantification was implemented and validated at 3T in phantoms and 6 healthy volunteers. |
| 4490 | Computer #55 |
Repeatability and reproducibility of in vivo magnetic resonance T1rho relaxation time measurements of hip cartilage at 3T |
1CREATIS, Université de Lyon ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Claude Bernard Lyon 1, Lyon, France, 2Radiologie et Imagerie médicale diagnostique et thérapeutique, Hôpital François Mitterrand, Dijon, France, 3Radiologie Pavillon B, Hôpital Edouard Herriot, Hospices Civils de Lyon, INSERM U1033 and Université Lyon 1, Lyon, France |
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To detect early changes in cartilage, quantification methods were developed with Magnetic Resonance Imaging. T1rho sequence is a valuable tool to quantitatively access the proteoglycans content, complementary to T2 mapping technique that is correlated with the collagen content. The thin cartilage thickness and deep location of the hip joint require a strong compromise between SNR, pixel size and acquisition time. The aim of this study is to test the repeatability and reproducibility of in vivo (magnetic resonance) T1rho and T2 relaxation times measures in the hip joint cartilage of thirty healthy asymptomatic volunteers. |
| 4491 | Computer #56 |
Osteochondral lesion depth on MRI can help predict the need for a sandwich procedure |
1Orthopedics, UMC Utrecht, Utrecht, Netherlands, 2Radiology, UMC Utrecht, Utrecht, Netherlands |
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Autologous subchondral bone grafting combined with ACI (sandwich procedure) is a well-accepted procedure for the treatment of osteochondral lesions of the knee. This requires a different surgical technique and preoperative planning. Also pain from bone marrow donor site location is expected and should be part of patient consent and expectations. This study evaluates whether MRI is able to predict the need for a sandwich procedure to help in optimizing the preoperative planning and consent. |
| 4492 | Computer #57 |
7 Tesla quantitative hip MRI: A comparison between TESS and CPMG for T2 mapping |
1Erwin L. Hahn Institute for MRI, University Duisburg-Essen, Essen, Germany, 2Department of Diagnostic and Interventional Radiology and Neuroradiology, University Duisburg-Essen, University Hospital, Essen, Germany, 3Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland, 4Department of Biomedical Engineering, University of Basel, Basel, Switzerland, 5High Field and Hybrid MR Imaging, University Duisburg-Essen, University Hospital, Essen, Germany |
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Purpose was the assessment of TESS T2 relaxometry in comparison to standard CPMG as a potential candidate to improve workflow in quantitative hip MRI protocols at 7T. A total of 8 healthy volunteers were included. T2 relaxation times were measured by manually drawing regions of interest in both acetabular and femoral cartilage in multiple regions of the hip joint. Compared to CPMG, TESS provides systematically reduced T2 values in both hip cartilage layers, in line with previously reported values. Nevertheless, with a 5-fold increase in spatial coverage TESS seems to be a good candidate to improve hip protocols at 7T. |
| 4493 | Computer #58 |
Repeatability of R1ρ, R2, and R2* in Knee Cartilage |
1Radiology, University of Cambridge, Cambridge, United Kingdom, 2GE Healthcare, Amersham, United Kingdom, 3GE Healthcare, Milwaukee, WI, United States |
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R1ρ, R2, and R2* imaging have been considered as biomarkers of degenerative cartilage diseases. In order to ensure the reliability of these measurements, we acquired data in eight subjects twice and compared measurements of variability. R1ρ-measurements had lower variability (CVRMS=21%) and a higher correlation to age (r2-value=0.566) when compared to R2 (r2-value=0.183; CVRMS=25%) and R2* (r2-value=0.092; CVRMS=38%). These measurements suggest that R1ρ is a more sensitive biomarker than R2 or R2*. |
| 4494 | Computer #59 |
Diffusion Weighted MRI of the Fibrous Structure of the Meniscus of the Knee: In Vitro Studies at 11.7T |
1University of California, San Diego, San Diego, CA, United States, 2Ningbo Jansen NMR Technology Co., Ltd., Cixi, Zhejiang, China, People's Republic of |
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In vitro high resolution diffusion weighted imaging of the meniscus of the knee at 11.7T shows detailed structure of fiber groups that has not previously be seen with MRI. There were clearly differentiated from cartilaginous areas of the meniscus. The diffusion contrast adds to that which results from the magic angle effect. This acts as a T2 filter. The diffusion contrast has more flexibility than magic angle contrast since it is not dependent on B0 and in principle any diffusion direction can be used. The results may be translatable to high field clinical systems. |
| 4495 | Computer #60 |
Spotlight on gagCEST imaging in human menisci with MR-microimaging on ultra-high field 7T - a pilot study |
1High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 2Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria, 3Department of Orthopaedic Surgery, Medical University of Vienna, Vienna, Austria, 4Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, 5Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia |
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The purpose of this study was to examine whether gagCEST imaging reflects the histopathological changes concerning glycosaminoglycan in human meniscus in vitro. All MRI acquisitions were performed on 7T MRI with a microimaging system. Histological staining using safranin-O was performed for correlation to imaging findings. Qualitatively, the gagCEST map and the corresponding safranin-O image show the same relative regional intensity of glycosaminoglycans. In sum, gagCEST imaging in a 7T microimaging system allows a very detailed look into the glycosaminoglycan distribution in the human meniscus.
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| 4496 | Computer #61 |
Diffusion Weighted 3D UTE in the Posterior Cruciate Ligament |
1Global MR Applications & Workflow, General Electric, San Diego, CA, United States, 2University of California San Diego, San Diego, CA, United States |
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In this work, we used a stimulated echo prepared diffusion 3DUTE sequence to image the posterior cruciate ligament. Volunteer scans in the knee were performed. We found that stimulated echo based diffusion weighted 3DUTE MR imaging can be used effectively to achieve useful b-values in short T2 MSK tissues. This initial proof-of-principle study shows good quantitative agreement with clinical EPI diffusion sequences. |
| 4497 | Computer #62 |
Open MRI of FAI: Reader agreement of a new method for quantifying femoroacetabular clearance for hips in an impingement posture |
1Orthopaedics, University of British Columbia, Vancouver, BC, Canada, 2Centre for Hip Health and Mobility, Vancouver, BC, Canada, 3Radiology, University of British Columbia, Vancouver, BC, Canada, 4Arthritis Research Canada, Richmond, BC, Canada, 5Vancouver Coastal Health, Vancouver, BC, Canada, 6University of British Columbia, Vancouver, BC, Canada |
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In this study, we describe a novel open MRI method for evaluating femoroacetabular impingement (FAI) in subjects with and without symptomatic FAI. First, we acquired images of subjects in postures suspected of inducing impingement using a T1-weighted gradient echo MR sequence. Second, readers measured β-angle to quantify clearance between the femur and acetabulum. Reader agreement for β-angle was equivalent or better to agreement when measuring α-angle, a similar structural measure. The open MRI method has the potential to assess functional relationships between the femur and acetabulum that otherwise cannot be assessed with closed-bore MRI scanners and conventional imaging protocols. This approach may be useful in addressing fundamental questions in FAI. |
| 4498 | Computer #63 |
Rapid T2 Relaxometry of the Meniscus, Tendons, and Ligaments with an Ultrashort Echo-Time Double-Echo Steady State Sequence |
1Radiology, Stanford University, Stanford, CA, United States, 2Bioengineering, Stanford University, Stanford, CA, United States, 3Electrical Engineering, Stanford University, Stanford, CA, United States |
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Quantitative MR imaging has the potential to provide information regarding the biochemical state of tissues and to track biochemical changes before the onset of morphological changes. However, with current MRI techniques, it is challenging to obtain signal from tissues with short-T2 relaxation times in the knee, let alone to perform quantitative imaging on them. Ultrashort echo-time double-echo in steady state (UTEDESS) is a pulse sequence that offers echo times of 50μs, and high resolution imaging with high SNR efficiencies. In this study, UTEDESS was also used to measure T2 relaxation times of the menisci, tendons, and ligaments in human knees. |
| 4499 | Computer #64 |
µMRI T2* mapping of degenerated human meniscal specimens compared to histology |
1High Field MR Centre, Department of Biomedical Imgaing and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 2Department of Orthopaedic Surgery, Medical University of Vienna, Vienna, Austria, 3Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria, 4Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Vienna, Austria, 5Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria |
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In this study, T2* maps of degenerated meniscal specimens were obtained using MRI on an ultra-high field scanner in combination with an MR microscopy insert and these images were compared to histological findings. The results showed that all five investigated menisci specimens had very similar morphological appearance when comparing histological images, T2* weighted images and T2* maps. |
| 4500 | Computer #65 |
Measurement of Fast T2* of the ACL Using 3D UTE Imaging |
1Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States, 2Radiology, Stony Brook University School of Medicine, Stony Brook, NY, United States, 3Orthopaedic Surgery, Stony Brook University School of Medicine, Stony Brook, NY, United States |
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3D-UTE imaging was utilized to estimate the fast T2* component of ACL after graft repair surgery. The average fast T2* component in the grafted ACL 3 months post-surgery for eight subjects is 1.66 +/- 0.4 ms. Two subjects currently have both 3 and 6 month post-surgery images. The ACL average fast T2* component went from 2.55ms to 1.81ms at three and six months post-surgery respectively for the first subject, and 1.39ms to 1.24ms for the second subject. The results demonstrate promise for 3D-UTE T2* mapping of bound water to evaluate ACL repair. |
| 4501 | Computer #66 |
Variable angle GLCM analysis for T2 maps of osteoarthritic knee cartilage with endpoint analysis: Oulu Knee Osteoarthritis study |
1Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland, 2Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, 3Research group of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland |
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Texture analysis methods based on gray level co-occurrence matrices can be optimized to probe the spatial information from knee MR T2 maps and of the changes caused by osteoarthritis. Curvature of the cartilage surfaces and relatively low resolution in relation to cartilage thickness set special requirements for texture analysis tools. Here we report an optimized analysis tool with customized point-wise offset angle and endpoint extrapolation for cartilage texture analysis. Method provides excellent performance compared to traditional texture analysis implementation. |
| 4502 | Computer #67 |
Comparing The Performance Of 3D T1W-WATS Sequence With 2D T2* FFE Sequence In Cartilage Changes Of Pediatric Hemophilic Joints |
1Beijing Children's Hospital Affiliated To Capital Medical University, Beijing, China, People's Republic of, 2Imaging systems Clinical Science,Philips Healthcare, Beijing, China, People's Republic of |
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Comparing the performance of 3D T1W-WATS sequence with 2D T2*W FFE sequence in the evaluation of cartilage damage in Pediatric hemophilia joints. 16 hemophiliac joints including 8 knees and 8 ankles were scanned on a 3.0 T, signal to noise of Cartilage, relative contrast between cartilage and surrounding tissue and the impact of hemosiderin were employed to compare.Our result showed that 3D T1W-WATS sequence had better relative contrast between cartilage and surrounding tissues and the immunity to hemosiderin compared with 2D T2*W sequence.3DT1W-WATS sequence can be performed in the evaluation of cartilage damage in hemophilia patients. |
| 4503 | Computer #68 |
Effects of the acquisition window length on articular cartilage sodium MR image quality |
1School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada, 2Imaging Research Centre, St Joseph's Healthcare, Hamilton, ON, Canada, 3Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada |
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We assessed articular cartilage sodium MR image SNR and blurring as a function of acquisition window length. Increasing the acquisition window dramatically improved the SNR with minimal reduction in image quality as shown by minimal blurring. |
| 4504 | Computer #69 |
Simultaneous Extraction of ADC and T2: Validation of Quantified DESS Sequence at 3T and 7T |
1Electrical Engineering, Brigham Young University, Provo, UT, United States, 2Biomedical Imaging, Electrical Engineering, University of Oxford, Oxford, United Kingdom, 3Radioligy, Stanford University, Palo Alto, CA, United States |
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A modification of the dual-echo steady state (DESS) pulse sequence was recently proposed that allows the extraction of both T2 and apparent diffusion coefficient (ADC) maps from a pair of DESS acquisitions (termed quantitative DESS, or qDESS). A careful validation of the accuracy of the qDESS T2 and ADC estimates has not yet been performed. The qDESS sequence produces accurate, high-resolution ADC and T2 maps. This is especially notable at 7T, where transmit B1 inhomogeneity makes it very difficult to produce reasonable T2 maps using typical multi-echo spin echo techniques. The qDESS technique shows great promise in providing both high-resolution morphological data and maps of T2 and ADC at 3 and 7 Tesla. |
| 4505 | Computer #70 |
Diffusion MRI models for Cartilage: beyond the Diffusion Tensor |
1Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Department of Orthopaedic Surgery, New York University School of Medicine, New York, NY, United States, 3Radiologisches Zentrum München-Pasing, Munich, Germany |
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The current DTI model has shown promise in capturing the early trends of change in cartilage. However, the model is very sensitive to the noise in the signal, hence blurring the contrast in the the anisotropy maps. Here we propose a simplification of the 6-parameter model to a 4-parameter one, called the "Zeppelin". The biophysical description that the Zeppelin makes remains the same and, additionally, provides fits that are more stable and provide better constrast. We also propose a new and simple 4-parameter multicompartment model (which is already known in neuroimaging). This provides an even more robust model fitting to the data, producing parameters that are analogous to those of Zeppelin, and promising more specificity to the early changes that occur in cartilage. |
| 4506 | Computer #71 |
Loading Significantly Influences the Zonal T1 of Medial Tibial Cartilage Topographically |
1Physics, Oakland University, Rochester, MI, United States, 2Center for Biomedial Research, Oakland University, Rochester, MI, United States, 3Univeristy of Calgary, Calgary, AB, Canada |
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This study aims to quantify the loading-modified T1 in articular cartilage using a canine model of early osteoarthritis (OA) at different degradation stages, at a 17.6µm resolution and with the use of Gd contrast agent. Both lesion and mechanical compression were found to alter T1 in cartilage at each sub-tissue zone and topographically, which provide a better understanding of the MRI properties of cartilage during joint loading. This result could help to design effective protocols in clinical MRI to better detect and manage the osteoarthritic diseases. |
| 4507 | Computer #72 |
Chondral Injury from ACL Injury: Monitoring Disease Progression |
1Department of Radiology and Imaging - MRI, Hospital for Special Surgery, New York, NY, United States, 2Sports Medicine and Shoulder Service, Hospital for Special Surgery, New York, NY, United States, 3Mayo Clinic, Rochester, MN, United States, 4University of California San Francisco, San Francisco, CA, United States |
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this is a synopsis |
| Exhibition Hall | Thursday, May 12, 2016: 14:30 - 15:30 |
| 4508 | Computer #73 |
Functional Changes in Medial Gastrocnemius from Unilateral Limb Suspension Induced Acute Atrophy: a 2D Strain Rate Study during Isometric Contraction |
1Physics, University of California at San Diego, San Diego, CA, United States, 2Physics, San Diego State University, San Diego, CA, United States, 3Radiology, University of California at San Diego, San Diego, CA, United States |
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Unilateral limb suspension is a controlled method to generate acute atrophy. The loss of muscle force with acute atrophy may be due to changes in contractile elements and extracellular matrix (ECM); a study of the strain rate (SR) patterns could provide information on these changes. Subjects were assessed at baseline (pre-ULLS) and post-ULLS using dynamic velocity encoded phase contrast MR imaging. The indices extracted from the SR tensor show at post-ULLS (i) a decrease in the asymmetry of deformation in the fiber cross-section and (ii) larger SR-muscle fiber angles. These findings may reflect a loss of integrity in the ECM. |
| 4509 | Computer #74 |
Physiological insights into medial gastrocnemius function during eccentric contraction in normal and in acute atrophy – Quantification of 2D strain rate indices from Velocity Encoded Phase Contrast MR Imaging. |
1Physics, San Diego State University, San Diego, CA, United States, 2Physics, University of California at San Diego, San Diego, CA, United States, 3Radiology, University of California at San Diego, San Diego, CA, United States |
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In-vivo studies of muscle function under different motion paradigms can elucidate the physiology of acute atrophy. This study maps the 2D strain rate tensor in subjects performing eccentric contractions before and after Unilateral Limb Suspension induced acute atrophy. As expected, strain rate values are smaller during eccentric compared to isometric contractions, since in the eccentric mode, muscle contraction occurs under lengthening conditions resulting in a net smaller local elongation. Changes of SR indices with atrophy are negligible possibly due to a balance of force loss from atrophy and greater force generation from a potentially stiffer matrix. |
| 4510 | Computer #75 |
Feasibility study of interleaved multi-nuclear acquisitions on a 3 T clinical NMR scanner without hardware modifications |
1NMR Laboratory, Institut of Myology, Paris, France, 2NMR Laboratory, CEA/DSV/I2BM/MIRCen, Fontenay-aux-Roses, France |
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NMR allows to investigate multiple aspects of physiological parameters like regional perfusion, blood and tissue oxygenation, intracellular pH or high-energy phosphate metabolism. In the past, interleaved multiparametric multinuclear dynamic NMR imaging and spectroscopy of skeletal muscle was developed on prototype scanners. Here we evaluated an interleaved pulse sequence combining the NMR acquisition of a 1H image and 31P spectrum on a clinical system without any hardware modifications from the customer. Having the possibility to run interleaved multinuclear sequences on unmodified clinical systems will greatly facilitate simultaneous measurements of tissue perfusion, oxygen content and mitochondrial ATP production in clinical research studies. |
| 4511 | Computer #76 |
Comparison of T2-prepared 3D TSE with multi-echo spin-echo sequences for T2 mapping of thigh muscles in healthy volunteers |
1Neuroradiology, Technische Universität München, München, Germany, 2Radiology, Technische Universität München, München, Germany, 3Neurology, Technische Universität München, München, Germany, 4Philips Healthcare, Hamburg, Germany |
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There is a growing interest for applying T2 mapping for non-invasively tracking inflammatory changes in patients with neuromuscular diseases. T2 has been traditionally quantified using multi-echo spin-echo (MESE) sequences with known problems related to the refocusing pulses in presence of B1-inhomogeneity and slice profiles effects. The present work proposes the combination of an adiabatic T2-preparation with 3D TSE for B1-insenstive T2 mapping. The proposed method is compared with 2D-MESE and 3D-MESE, in terms of reproducibility on T2 quantification and sensitivity to B1 effects, in the thigh musculature of ten healthy subjects. |
| 4512 | Computer #77 |
T2* Mapping of Lower Leg Muscles Following Single Brief Contractions at 3 T |
1Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Siemens Medical Solutions USA, Siemens Healthcare, New York, NY, United States, 3Department of Radiology, Michigan State University, East Lansing, MI, United States |
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Microvascular function in the skeletal muscle can be assessed through blood oxygenation level dependent (BOLD) MRI signal changes after performing a brief exercise or following a period of induced ischemia. Such BOLD related relaxation changes are mainly attributed to intravascular mechanisms, such as changes in the hemoglobin content and oxygen saturation levels. In this work, we developed and implemented a rapid echo-planar imaging (EPI) method to map T2* changes, following a single maximum voluntary contraction on a 3 T whole body clinical scanner. |
| 4513 | Computer #78 |
Quantitative Assessment of Muscle Fat in Sarcopenia Using Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) |
1Institute of Medical Physics, Erlangen, Germany, 2Product Definition & Innovation, Siemens Healthcare GmbH, Erlangen, Germany, 3Institute of Radiology, University Hospital Erlangen, Erlangen, Germany, 4Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany |
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Sarcopenia describes muscle degeneration. In particular with increasing age, muscle tissue is replaced by fatty infiltrations. We developed an MRI sequence protocol (T1w TSE, PDw SPACE, PDw TSE Dixon, q-Dixon, and HISTO) for quantifying this degradation and applied it twice to 54 patients suffering from sarcopenia. Between both measurements three months of whole body electromyostimulation (EMS) training were performed. Initial results show that image data can be used for muscle segmentation and determination of muscle volumes, fat fractions, and fat distribution within the muscles. Muscle fat fractions correlate with muscle strength. In spectroscopy accurate voxel repositioning is challenging. |
| 4514 | Computer #79 |
Foot Oximetry Angiosomes with MRI |
1Radiology, Washington University in St. Louis, St. Louis, MO, United States, 2Radiology, Peking University First Hospital, Beijing, China, People's Republic of, 3Surgery, Washington University in St. Louis, St. Louis, MO, United States, 4The Program in Physical Therapy, Washington University in St. Louis, St. Louis, MO, United States |
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The objective of this study was to develop a non-contrast MRI based oximetry approach to assess the skeletal muscle microcirculation in diabetic and healthy feet. In both healthy and subjects with diabetes, the feasibility of the foot oximetry was examined when the subjects were at rest and during a toe-flexion isometric exercise. The percent difference in the areas of the oxygen extraction fraction within the 0.7 – 1.0 range between rest and exercise was significantly different between healthy subjects and subjects with diabetes. This is the first MRI foot oximetry developed for assessing regional skeletal muscle oxygenation. |
| 4515 | Computer #80 |
Correlation between sodium and T1ρ dispersion in human calf muscle |
1Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, 2Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 3Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, United States |
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Simultaneous acquisitions of sodium concentrations and T1ρ in muscles from different aged individuals show that sodium values increase with age and are accompanied by increases in the dispersion of spin-lock relaxation rates (i.e. the difference in R1ρ = 1/T1ρ at low and high locking frequencies). A previous study has suggested that such differences in R1ρ at different fields reflects the contribution of chemical exchange to relaxation, which is known to dominate transverse relaxation at high fields, and potentially reflects GAG concentration in cartilage. In this study, we found ΔR1ρ in muscle was smaller than in cartilage at 3T but was measureable and showed a strong correlation with sodium content in muscle. The increase in sodium with age possibly corresponds to the loss of muscle mass and increase in extracellular volume within a voxel, but this appears to be accompanied by an increase in exchangeable protons as well. |
| 4516 | Computer #81 |
Automatic segmentation for volume quantification of quadriceps muscle head in athletes during an extreme mountain ultra-marathon |
1LIRMM; CNRS (UMR 5506) Université de Montpellier, Montpellier, France, 2Radiology Dept, CHU de Saint Etienne, Saint Etienne, France, 3CREATIS, Université de Lyon ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Claude Bernard Lyon 1, Saint Etienne, France, 4Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland, 5CREATIS, Université de Lyon ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Claude Bernard Lyon 1, Villeurbanne, France |
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Acute loss of skeletal muscle mass is a common feature of several pathologies such as stroke, cancer, chronic obstructive pulmonary disease. Having a none invasive method to accurately quantify muscle mass is of crucial interest to follow procedure that could prevent muscle wasting and restore physical capacity, mobility and optimize motor recovery. The aim of the current study is to propose an automatic segmentation technique to quantify muscle mass. The automatic segmentation of 3D quadriceps volumes was performed using a deformable registration technique applied to 3D isotropic in-phase (IN), out-phase (OUT), and calculated fat (F) and water (W) images obtained using a double-echo gradient echo Dixon coronal acquisition in order to test the best contrast channel for segmentation. The method was tested in a longitudinal study in athletes enrolled for the most extreme mountain ultra-marathon (The Tor des Géants, Courmayeur, Italy: +24000 positive elevation, 330km). 51 athletes were scans at departure, 27 finishers at the arrival and 2 days after recovery, leading to 105 datasets that were segmented in total. The best automatic segmentation accuracy was obtained when using the calculated Water image (DSC=0,946). |
| 4517 | Computer #82 |
Simultaneous quantitative susceptibility, PDFF and transversal relaxation time mapping in dystrophic skeletal muscle |
1Center of Research on inflammation; Inserm U1149, Université Paris Diderot, Paris, France, 2CREATIS CNRS UMR 5220; Inserm U1044, Université de Lyon, Villeurbanne, France, 3CRMBM; CNRS UMR 7339, Aix-Marseille University, Marseille, France, 4Genetique Médicale et Génomique Fonctionelle; Inserm UMR S_910, Aix Marseille University, Marseille, France, 5CEMEREM, Hopital de la Timone, Pôle d’imagerie médicale, AP-HM, Marseille, France |
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We have developed a dedicated algorithm allowing to quantify, from a single MR acquisition fat and muscle fractions together with magnetic susceptibility and transverse relaxation time (T2*). This approach was linked to a dedicated segmentation algorithm allowing to quantify specific indices which could be of interest for the assessment of disease severity and progression. Our results showed the feasibility of quantitative susceptibility mapping (QSM) in thigh muscles and demonstrated that its implementation into the fat-water separation reconstruction pipeline is possible. For dystrophies assessment, magnetic susceptibility-related information might provide a useful supplementary materials in comparison to relaxometry and fat fraction measurements. |
| 4518 | Computer #83 |
Evaluation of Cuff-Induced Skeletal Muscle Microvascular Perfusion of Lower Extremity by ASL and IVIM MRI techniques |
1Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China, People's Republic of, 2GE Healthcare China, Shanghai, China, People's Republic of |
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Arterial spin labeling (ASL) and intravoxel incoherent motion (IVIM) are both noninvasive MRI techniques that offer quantitative perfusion measurements. The current study showed that the ASL perfusion decreased while the IVIM vascular volume fraction increased compared to baseline under cuff compression paradigm in the lower extremity muscle, indicating that the two MRI techniques based on two completely distinct mechanisms provide complementary tissue perfusion characteristics. |
| 4519 | Computer #84 |
Quantitative MR evaluation of fatty infiltration and edema-like processes in skeletal muscles of Myotonic Dystrophy type 1 |
1Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, Netherlands, 2Department of Neurology, Radboud university medical center, Nijmegen, Netherlands |
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We used quantitative MR to evaluate the extent of fatty infiltration and edema-like processes in muscles of patients with Myotonic Dystrophy type 1 (DM1). Fat fractions were obtained using a DIXON method and the T2 of muscle water (T2water) was calculated using a bi-component extended phase graph model. The results show that fatty infiltration in DM1 is a slow gradual process whereby the distal part of the muscle is more heavily fat infiltrated than the proximal part. In addition, muscles that are in an active process of fatty infiltration have an elevated T2water, possibly from reactive edema. |
| 4520
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Computer #85 |
Rapid High Resolution 3D Musculoskeletal Imaging at 7T: Contrast Optimization and Comparison of DESS, Phase-Cycled bSSFP, and 3D SPACE |
1Electrical Engineering, Brigham Young University, Provo, UT, United States, 2Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom |
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In this study, we (1) implemented a two-acquisition 3D phase-cycled bSSFP protocol at 7 Tesla that achieves 0.31mm isotropic resolution in under 9 minutes of scan time, (2) implemented a 3D DESS protocol at 7 Tesla that achieves 0.36mm isotropic resolution in just under 7 minutes, (3) performed a contrast optimization to identify flip angles that maximize both cartilage/muscle and cartilage/synovial fluid contrast, and (3) compared to a 3D SPACE acquisition at 7T that achieves 0.55mm isotropic resolution in a scan time of 11:37. |
| 4521
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Computer #86 |
1H MRS can detect and quantify acetylcarnitine in different human skeletal muscles at rest at 7T. |
1High-Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, 2Faculty of Chemical and Food Technology, Department of NMR Spectroscopy and Mass Spectrometry, Slovak University of Technology in Bratislava, Bratislava, Slovakia, 3Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria, 4John Radcliffe Hospital, University of Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, United Kingdom, 5Department of Imaging Methods, Institute of Measurements Science, Slovak Academy of Sciences, Bratislava, Slovakia, 6Center of Sport Science and University Sport, University of Vienna, Vienna, Austria, 7Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria |
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Carnitine plays an important role in fat metabolism. A long-echo time (TE of 350ms) proton magnetic resonance spectroscopy protocol was implemented for detection of skeletal muscle acetylcarnitine at rest on a clinical 7T scanner in the calf (soleus) and thigh (vastus lateralis) muscle. T2 relaxation times of the 2.13 ppm signal of acetlylcarnitine at 7T were assessed as 137.8±47.7ms. Concentrations of acetylcarnitine in vastus lateralis muscle in four healthy volunteers were found to be 1.69±0.21mmol/kg wet weight, whereas lower concentrations (i.e., 0.54±0.19mmol/kg) were found in soleus muscle. |
| 4522 | Computer #87 |
A Low-Cost MR Compatible Ergometer For Assessing Lower Leg Muscle Metabolism |
1Department of Radiology, New York University School of Medicine, New York, NY, United States, 2NYU WIRELESS, Polytechnic Institute of New York University, Brooklyn, NY, United States |
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In this work, we designed and constructed an inexpensive MR compatible ergometer that can be used for studying lower leg muscle metabolism. This ergometer allows subjects to perform a plantar flexion exercise protocol while 31P-MR data are acquired. The device is easy to use, and it can be positioned inside the bore of the magnet in less than 10 min. The mechanical power exerted by the subject can be estimated from force and angle displacement signals that are continuously monitored, while the exersice intensity can be varied by changing the number and/or the material of the resistive elastic cords. |
| 4523 | Computer #88 |
What is the Relationship between Vascular Disease Distribution in PAD and Exercise-Induced Hyperemia Pattern in Calf Muscle? |
1Radiology, Utah Center for Advanced Imaging Research (UCAIR), University of Utah School of Medicine, Salt Lake City, UT, United States, 2Internal Medicine, Division of Geriatrics, Utah Vascular Research Lab (UVRL), University of Utah School of Medicine, Salt Lake City, UT, United States, 3Surgery, University of Utah School of Medicine, Salt Lake City, UT, United States |
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Calf muscle perfusion by first-pass gadolinium MRI provides objective measures to help understand the relationship between vascular pathology and muscle dysfunction in peripheral arterial disease (PAD) patients. We compared perfusion in healthy and PAD subjects in exercise-recovery and, in the same PAD patients, related muscle perfusion pattern to hemodynamically significant vessel pathology found at MR arteriography. We found no relation between specific stenosis/occlusion and the expected muscle perfusion downstream, but calf vascular pathology significantly decreased perfusion in the superficial posterior compartment muscles compared to abdominopelvic/thigh vessel abnormality. Assessing muscle perfusion shows promise in assessing PAD disease severity and guiding treatment. |
| 4524 | Computer #89 |
Magnetic resonance imaging estimates of muscle volume and inter-muscular fat in the thigh in sarcopenia population: correlation with physical performances |
1Institute of Geriatrics and Active Ageing, Tan Tock Seng Hospital, Singapore, Singapore, 2Department of Diagnostic Radiology, Tan Tock Seng Hospital, Singapore, Singapore |
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This study presented using MRI to quantify muscle and fat volumes in thigh for sarcopenic and sarcopenic obese (SO) populations. The correlation between different thigh components and patients’ physical performances was also assessed. Results show that MRI is a promising tool for early detection of sarcopenia and SO. This may translate to use in clinical trials and in clinical practice. MRI measurement of inter-muscular fat volume is a valuable component in thigh to monitor patients’ physical performances. |
| 4525 | Computer #90 |
Comparison of relative RF power deposition for shoulder MRI at 3.0T and 7.0T using 3D dual echo steady state imaging |
1HELIOS Klinikum Berlin Buch, Radiology, Max Delbrück Center for Molecular Medicine (MDC) Berlin,Ultrahigh Field Facility (B.U.F.F.), Berlin, Germany, 2Max Delbrück Center for Molecular Medicine (MDC), Ultrahigh Field Facility (B.U.F.F.), Berlin, Germany, 3HELIOS Klinikum Berlin Buch, Radiology, Berlin, Germany, 4Max Delbrück Center for Molecular Medicine (MDC), Experimental and Clinical Research Center (ECRC), Charite Campus Berlin Buch, Humboldt University Berlin, Ultrahigh Field Facility (B.U.F.F.), Berlin, Germany |
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Technology advances in ultra-high field systems improve significantly diagnose of different musculoskeletal structures. A challenge of this work examines relative RF power deposition for shoulder MRI with dual echo steady state imaging at 3.0T and 7.0T. Volunteers (n=10, mean age 36.5 ± 8.51 years) were investigated at 3.0 T and 7.0 T. The flip angle was varied for each field strength. A comparison of flip angle between 3.0T and 7.0T showed a SAR gain of approximately 2.6 for the local RF coil setup used at 7.0 T versus the body coil configuration employed at 3.0 T. It is important to considering a right choice of sequences and these parameters. |
| 4526 | Computer #91 |
Fat infiltration is non-uniform along the proximodistal muscle axis in Duchenne Muscular Dystrophy |
1Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Neurology, Leiden University Medical Center, Leiden, Netherlands |
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Progressive replacement of muscle tissue by fat is one of the main characteristics of DMD. This muscle degeneration process has been extensively studied in terms of differences between individual muscles, but not as a function of physical location within each individual muscle. This work showed non-uniform fat infiltration along the proximodistal muscle axis within individual muscles using the Dixon water/fat technique. These observations provide new insight into disease progression in DMD. |
| 4527 | Computer #92 |
Towards Fast and Robust Bilateral Brachial Plexus Imaging |
1Global MR Applications & Workflow, GE Healthcare, Madison, WI, United States, 2Global MR Applications & Workflow, GE Healthcare, Houston, TX, United States, 3Department of Imaging Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States, 4MR Engineering, GE Healthcare, Waukesha, WI, United States, 5Global MR Applications & Workflow, GE Healthcare, Waukesha, WI, United States, 6Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States |
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MR imaging of bilateral brachial plexus has been challenging due to various reasons, such as fat suppression failures caused by B0 inhomogeneity, arms wrapping in arms-down imaging for patient comfort, and long scan time, etc. In this work, these aforementioned challenges were addressed by combining and utilizing novel MR imaging techniques, and a fast and robust protocol for bilateral brachial plexus MR imaging is proposed. |
| 4528 | Computer #93 |
Fasciculation MR Imaging (faMRI) of the Lower Leg |
1Radiology, University of California, San Diego, San Diego, CA, United States |
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Fasciculations are brief spontaneous contractions affecting a small number of muscle fibers. We investigated how diffusion sensitized MR images were able to detect these contractions in the lower leg of healthy volunteers. Large intensity decreases were observed (at random times) in random areas of muscle on images, acquired repeatedly using single shot (diffusion sensitized) EPI acquisitions over the course of several minutes. Signal intensity reductions were attributed to intra-voxel incoherent-like motion due to displacement of tissue. Quantification compared activated areas to total muscle area and frequency of activation on a per pixel basis. Results were expressed as a fasciculation index parameter and in fasciculation frequency maps. |
| 4529 | Computer #94 |
Towards high temporal resolution Creatine Chemical Exchange Saturation Transfer (Cr-CEST) during plantar flexion exercise: Preliminary results at 7T |
1High Field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 2Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria |
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Once the technical limitations are cleared, Cr-CEST could replace 31P-MRS, becoming a powerful tool for assessment of treatment outcomes and diagnosis of muscular disorders, due to its superior spatial resolution and sensitivity. Phantom measurements show how Cr concentration and pH are linearly correlated with CEST contrast maps. The preliminary in-vivo measurements, with a time resolution of 13.1s per repetition, produce an enhancement of gastrocnemius muscle of 12% during plantar flexion exercise. However, a further increased time resolution is anticipated for dynamic studies, close to those routinely used in dynamic 31P-MRS. |
| 4530 | Computer #95 |
High-Resolution DTI of Distal Peripheral Nerves Using Flow-Compensated Diffusion-Prepared 3D TSE |
1Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, 2Radiology, Academic Medical Center, Amsterdam, Netherlands, 3Philips Healthcare, Best, Netherlands, 4Philips Healthcare, Hamburg, Germany, 5Zentralinstitut für Medizintechnik, Garching, Germany, 6Neuroradiology, Technische Universität München, Munich, Germany |
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Quantitative MRI is becoming a promising tool in the assessment of peripheral nerve pathologies and anomalies. Peripheral neuropathy is frequently accompanied by neuropathic changes, which can be quantified with diffusion tensor imaging (DTI). Given the small sizes and oblique geometries of many peripheral nerves, peripheral-nerve DTI requires an acquisition method that can provide high-resolution, distortion-free images in acceptable clinical scanning times. The present work demonstrates isotropic- and sub-millimeter-resolution, artifact-free DTI of the nerves in the lower extremity using flow-compensated diffusion-prepared 3D turbo spin echo (TSE). |
| 4531 | Computer #96 |
Volumetric Brachial Plexus Imaging at 3T with Dual-echo Dixon TSE: comparison against 3D STIR and 3D SPAIR |
1Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 2Philips Innovation Campus, Philips Healthcare, Bangalore, India, 3Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States |
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Volumetric Brachial Plexus imaging at 3T often suffers from incomplete fat suppression and reduced SNR with standard STIR and SPAIR due to increased B1 and B0 inhomogeneities. Dual-echo Dixon TSE has been shown to achieve uniform fat suppression without increasing total scan time or SNR penalty by acquiring two echoes in the same repetition. In this work, we compared 3D dual-echo Dixon TSE against current standard of care 3D STIR and 3D SPAIR for brachial plexus imaging with respect to fat suppression, blood suppression, nerve visualization and SNR at 3T. Overall, the 3D dual-echo Dixon TSE showed significantly improved performance. |