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| Exhibition Hall | Monday 8:15 - 10:15 |
| 1272 | Joint Reconstruction of Simultaneous PET/MR Imaging with Motion Correction Using a B-spline Motion Model | |
1Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China, 2Key Laboratory of Particle and Radiation Imaging, Ministry of Education, Medical Physics and Engineering Institute, Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China |
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Joint Reconstruction (JR) is an important approach to utilize the similarity of PET and MRI in simultaneous PET/MR imaging. For now, almost all the JR models ignore the effect of motion during scan, leading to blurring in images. We propose a motion correction method under the framework of JR, assuming that PET images and MRI images share exactly the same motion field and using a B-spline free deformation model to describe the motion. Both simulation and patient study show that the proposed method can reduce the blurring caused by motion in PET and MR images. |
| 1273 | Motion Correction for Magnetic Resonance Fingerprinting by Using Sliding-Window Reconstruction and Image Registration | |
1School of Biomedical Engineering, Guangdong Provincial Key Laborary of Medical Image Processing, Southern Medical University, Guangzhou, People's Republic of China, 2laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, People's Republic of China, 3Department of Electrical and Electronic Engineering,The University of Hong Kong, Hong Kong SAR, People's Republic of China, 4Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong SAR, People's Republic of China, 5Philips Healthcare, Guangzhou, People's Republic of China, 6Department of Biomedical Engineering, Zhejiang University, Hangzhou, People's Republic of China |
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The recently proposed magnetic resonance fingerprinting (MRF) technique demonstrates to be motion insensitive, but the early motion during the acquisition can still lead to severe errors in parameter quantification. In this study, we present a novel motion correct method for MRF based on sliding-window reconstruction and image registration. |
| 1274 | Quantitative evaluation of prospective motion correction for structural imaging at 7T | |
1Department of Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Germany, 2German Center for Neurodegenerative Diseases, Magdeburg, Germany, 3Center for Behavioral Brain Sciences, Magdeburg, Germany, 4Leibniz Institute for Neurobiology, Magdeburg, Germany |
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The problem of motion in MRI scan still remains prevalent for many applications and numerous solutions for motion correction in MRI have been proposed to improve the image quality in presence of motion. Prospective motion correction using an optical tracking system has the advantage that it allows to eliminate motion artifacts without prolonging the overall scan time. In this study, we scanned healthy subjects at 7T with high resolution structural imaging sequences for diverse range of contrasts, which are commonly used in neuroscience applications. The final results show an improved image quality and a great potential of prospective motion correction. |
| 1275 | Validating the accuracy and effectiveness of Prospective Motion Correction on rsfMRI | |
1Cognition and Brain Science Unit, MRC, Cambridge, United Kingdom |
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Prospective motion correction for MRI has been shown to greatly improve image quality for structural scans but its impact on fMRI data is still unclear. In this work, we studied the effectiveness of prospective motion correction by analysing the accuracy of the tracking system and looking at the effects of motion correction on resting-state fMRI with no instructed subject motion. |
| 1276 | Quantifying the effectiveness of Prospective Motion Correction using a Visual fMRI task | |
1Cognition and Brain Science Unit, MRC, Cambridge, United Kingdom, 2Department of Systems Neuroscience, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany |
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Prospective Motion Correction (PMC) using an optical tracking system has been shown to improve data quality. We conducted a study on 18 subjects using robust visual stimuli to quantify the effectiveness of PMC on task-based fMRI. Our results show that PMC improves voxel-to-voxel registration across time and leads to better contrast-to-noise ratio. This is particularly evident in analyses which are more sensitive to inaccurate voxel registration and motion-induced noise. |
| 1277 | Free breathing & ungated cardiac cine MRI using joint smoothness regularization on image and patch manifolds (j-STORM) | |
1Electrical and Computer Engineering, University of Iowa, Iowa City, IA, United States, 2MR R&D, Siemens Healthcare, United States |
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A joint manifold smoothness regularization scheme (j-STORM) is proposed for free-breathing and ungated cardiac CINE imaging. The proposed method assumes that the images and square shaped image patches of the dynamic dataset live on a smooth, but separate, low-dimensional manifolds. We compare the reconstruction of two datasets from their highly undersampled measurements with the proposed j-STORM method to the image manifold smoothness scheme (STORM). The proposed scheme considerably reduces the streaking-artifacts present when only image manifold smoothness regularization is used and not the patch manifold smoothness. |
| 1278 | Automatic reference-free detection and quantification of MR image artifacts in human examinations due to motion | |
1Department of Radiology, University of Tuebingen, Tuebingen, Germany, 2Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany, 3Section on Experimental Radiology, University of Tuebingen, Tuebingen, Germany |
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MRI has a broad range of applications due to its flexible acquisition capabilities. This demands profound knowledge and careful parameter adjustment to identify stable sets which guarantee a high image quality for various and, especially in examinations of patients, unpredictable conditions. This complex nature and long examination times make it susceptible to artifacts which can markedly reduce the diagnostic image quality. An early detection and possible correction of these artifacts is desired. In this work we propose a convolutional neural network to automatically detect, localize and quantify motion artifacts. Initial results in the head and abdomen demonstrate the method’s potential. |
| 1279 | Gating PET data for cardiac imaging with radial MRI data | |
1Department of Clinical Radiology, University of Muenster, Muenster, Germany, 2European Institute for Molecular Imaging, University of Muenster, Muenster, Germany, 3Department of Nuclear Medicine, University Hospital Muenster, Muenster, Germany |
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The increasing availability of MR/PET scanners opens new perspectives for cardiac imaging. However, technical issues for the reconstruction of signal from the moving myocardium remain to be solved. Using the k-space center in radial cardiac MRI data allows for generating a robust gating signal. Here, MR data acquired with a radial FLASH sequence in a 3 T MR/PET scanner continuously during a 15 minutes PET acquisition were used for retrospective gating. The k-space center magnitude was used to sort MRI and PET data into different cardiac phases while respiration-corrupted data were excluded, resulting in well separated cardiac phases. |
| 1280 | Subject-specific 3D Modeling of Macaque Brain via Automatic Tissue Registration Based on in vivo MR Images Acquired at 7T | |
1Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University, Hangzhou, People's Republic of China, 2College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, People's Republic of China, 3Medical Imaging Department, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, People's Republic of China, 4MR Collaboration Northeast Asia, Siemens Healthcare, Shanghai, People's Republic of China |
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Accurate subject-specific 3D modeling of macaque brain with anatomical subdivisions is important for neuroscience, neurophysiology and engineering researches. In this study, we have proposed a feasible approach for automatically creating 3D models of macaque brain based on in vivo MR images. A 3D template of macaque brain, consisting of scalp, skull, grey matter, white matter, and cerebrospinal fluid, was firstly constructed from 7T T1w images over an anesthetized macaque; then, by implementing symmetric feature-based pairwise registration method, this template was used to register another in vivo 7T dataset of macaque brain, which enables automatic and subject-specific 3D macaque brain modeling. |
| 1281 | Estimating the bias associated with image registration in MRI | |
1NMR Unit, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany |
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The most promising techniques for understanding the biophysical basis of the MRI signals rely on combining multi-modal quantitative maps as a source of spatially-resolved information. If the MRI maps are not obtained from simultaneous acquisitions, they need to be co-registered in order to ensure a consistent localization of the signal sources for pixel-by-pixel fitting. However, the effects of the co-registration step are notoriously difficult to quantify. Here, we present a method for investigating the bias associated with co-registration for different quantitative MRI acquisitions, and outline the relevance of these biases for multi-parameter analysis. |
| 1282 | A Retrospective Cardiac Gating Method using Simultaneously Acquired Navigator | |
1Korea Advanced Institute of Science and Technology, Daejeon, Korea, Republic of |
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A cardiac gating method using a navigator MR signal requires the additional acquisition steps interleaved with the acquisition of image signals. To eliminate the additional acquisitions for navigators, the proposed method obtains an image signal and a navigator signal at the same time, and separates them in post-processing. Cardiac motion information estimated from the separated navigators is used for retrospective cardiac gating. To demonstrate the feasibility of the proposed method, in-vivo experiments were performed for cardiac MRI with short axis view. |
| 1283 | Prospective Self-Gating For Cardio-Respiratory Synchronised Imaging in the Mouse. | |
1Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom |
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Prospective cardio-respiratory self-gating is demonstrated in the mouse. A gradient echo scan operating at constant TR enabled acquisition of CINE data blocks or maintenance of the NMR steady state depending on the level of a gating control signal that was evaluated within each TR. A portion of the FID during each TR was submitted to a signal processor chain for streaming into a pseudo-continuous analogue cardio-respiratory signal trace and conversion to a series of logic control signals for gating. |
| 1284 | Fast motion robust abdominal stack of stars imaging using coil compression and soft gating | |
1Global MR Applications and Workflow, GE Healthcare, Houston, TX, United States, 2Global MR Applications and Workflow, GE Healthcare, Madison, WI, United States, 3GE Global Research Europe, Garching bei München, Germany, 4Cardiac Center of Excellence, GE Healthcare, Garching bei München, Germany |
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Stack of stars trajectory with golden angle ordering provides better motion robustness than Cartesian imaging for abdominal MRI. However, image reconstruction for non-Cartesian datasets is usually time-consuming, especially for datasets with high-density coil arrays. While additional motion correction methods can improve image quality for stack of stars, they often further increase the reconstruction time. In this work, we aim to reduce the reconstruction time for stack of stars using coil compression and improve motion robustness with a similar reconstruction time using soft gating. |
| 1285 | Golden-angle Sparse Liver Imaging: Radial or Cartesian Sampling? | |
1Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States, 2Siemens Healthineers, New York, USA |
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This work compares golden-angle stack-of-stars sampling and golden-angle Cartesian sampling for free-breathing liver MRI with eXtra-Dimensional (XD) compressed sensing reconstruction. For Cartesian sampling, the phase-encoding steps in the ky-kz plane are segmented into multiple interleaves that rotate at a golden angle. Each interleave starts from the center (ky=kz=0) of k-space and follows a pseudo-radial pattern on a Cartesian grid. Results from this initial study suggest that golden-angle Cartesian sampling achieves higher effective spatial resolution than radial sampling, but it still suffers from residual ghosting artifacts due to respiratory motion for free-breathing liver imaging. |
| 1286 | Motion-Correction Testing with an Anthropomorphic Brain Phantom | |
1Department of Electrical Engineering, University of Hawaii at Manoa, Honolulu, HI, United States, 2Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, United States |
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Motion-correction (MoCo) techniques enable clinicians to obtain high-quality MR images with decreased artifact from patient movement. MoCo methods can be tested on a phantom, but it is difficult to fully observe the benefits of MoCo on a simple phantom. In this study, we propose an anthropomorphic brain phantom with white matter and gray matter structure to work with a pneumatic motion simulator and demonstrate a practical application in a simulated motion study. |
| 1287 | How to correct block design task-induced coherent head motion; Evaluation of retrospective motion correction methods in HCP fMRI | |
1Radiology, Cleveland Clinic, Cleveland, OH, United States |
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Participants in block design finger tapping fMRI have a tendency to have paradigm coherent head motion. This finding appears to be very strong in HCP data, which utilizes spatially and temporally accelerated SMS sequence. We have introduced slice-oriented motion correction method (SLOMOCO1), and found SLOMOCO removed the head motion efficiently in HCP data, especially in the case that head motion pattern is synchronized to task paradigm. In this study, we compared the various motion correction methods in finger tapping fMRI HCP data. |
| 1288 | Phase-based Motion Detection for Diffusion Magnetic Resonance Imaging | |
1Diagnostic Radiology, University of Maryland School of Medicine, Baltimore, MD, United States, 2Neural and Pain Sciences and Orthodontics, University of Maryland Dental School, Baltimore, MD, United States, 3Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States |
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Diffusion-weighted imaging is sensitive to subject motion. Even small subject motion induces dramatic spin phase changes, allowing phase map to have higher sensitivity than the magnitude images to detect subtle motion. In this study, we derived metrics based on the Haralick features in DWI phase maps for automatic motion detection and data rejection in diffusion-weighted imaging data. The motion detection method is validated against motion tracked by an external electromagnetic motion tracking sensor. |
| 1289 | Motion Artifacts Reduction by Parallel Acquisition with Non-prolonged Deghosting Algorithm (PANDA) | |
1Advanced Applications, Alltech Medical Systems, Chengdu, People's Republic of China, 2Advanced Applications, Alltech Medical Systems America, Solon, OH, United States, 3Radiology, University of British Columbia, Vancouver, BC, Canada |
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Patient motion produces artifacts in MRI due to k-space data corruption. Ghosted images can be considered as a combination of ghost-free images and ghost masks. If two ghosted images contain the same ghost-free image component and different ghost components, the images and the ghost components can be separated. For images fully sampled with array coils, multiple images can be produced with parallel reconstruction with differently selected raw data subsets. In this work, we propose a new motion artifacts reduction algorithm, which regenerates a new k-space dataset based on data consistency, and then decomposes images into mostly ghost-free images and ghost masks. |
| 1290 | A Hybrid ECG/Self-Navigation Technique | |
1Medical Imaging, University Health Network, Toronto, ON, Canada, 2Medical Imaging, University of Toronto, Toronto, ON, Canada |
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In self-navigation, cardiac and respiratory information is extracted from the MR signal. ECG and conventional navigator echoes are not required. Conventional navigators disrupt the steady state and add delays. Thus, self-navigation provides a clear advantage. However, ECG is monitored independently of the MR acquisition. Therefore, eliminating the ECG needlessly throws away information. In this study, a hybrid ECG/self-navigated sequence is developed. ECG is used for cardiac triggering. Self-navigation is used for respiratory compensation, and to provide additional cardiac gating. In 10 healthy volunteers, the ECG/self-navigation sequence provided equivalent image quality and quantitative cardiac metrics as a reference breath-hold scan. |
| 1291 | Correction of Ghosting Due to Respiration-induced B0 Variation in Double Echo Steady State (DESS) Breast Imaging: Initial Validation | |
1Radiology, Stanford University, Stanford, CA, United States |
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Double Echo Steady State (DESS) breast imaging for T2 and diffusion-weighted imaging in the breast is limited due to prominent ghosting artifacts. While actual respiratory motion of the breast tissue is minimal due to the prone position of the patient as well as immobilization paddles on the coil, respiratory-induced B0-variation is a source of ghosting. A method based on a per-TR off-resonance estimate and simulated phase data for correction of ghosting artifacts in DESS in the breast is described and validated in eight breast cancer patients. The new method effectively reduces ghosting artifact greatly improving image quality. |
| 1292 | Markerless Optical Tracking for Motion Correction in MR and PET/MR Imaging of the Brain | |
1Department of Radiology, Stanford University, Stanford, CA, United States, 2Brain and Mind Centre, University of Sydney, Sydney, Australia |
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Optical prospective motion correction using markers attached to the patient’s head has been widely demonstrated to improve image quality in MRI of the brain. To simplify patient workflow, it would be helpful to remove the need for the marker. We have previously demonstrated markerless tracking using a stereo camera system, but this was done outside of the MR environment and used a 6-axis robot to validate tracking. In this work, we demonstrate markerless optical tracking in two volunteers during simultaneous MRI and use the markerless tracking data to retrospectively realign images. |
| 1293 | Image registration with structuralized Mutual Information: application to CEST | |
1Department of Radiology, Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 2Philips Research, Hamburg, Germany, 3Philips Healthcare, Gainesville, FL, United States |
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In image registration, mutual information (MI) has proved to be an effective similarity measure and is widely used for medical image registration. However, the MI algorithm does not consider spatial dependencies of voxels and introduces significant errors when registering images with large intensity changes, like in Z-spectral images of CEST-MRI. This abstract shows that by the incorporation of structural information the SMI algorithm demonstrates robust performance registering Z-spectral images with large and complex intensity variations. |
| 1294 | Synthetic MRI with Prospective Motion Correction | |
1Radiology, Stanford University, Stanford, CA, United States, 2Global MR Applications & Workflow, GE Healthcare, Rochester, MN, United States, 3Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States |
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Quantification of tissue parameters such as T1, T2 and PD has gained significant interest due to potential applications in characterization of certain pathologies (Alzheimer’s, multiple sclerosis, etc.). One such technique, called “Synthetic MRI”, utilizes a fast spin echo (FSE) readout with inversion recovery in order to simultaneously get T1, T2 and PD maps using a single scan. In this abstract, we demonstrated that application of optical motion correction to simultaneous T1, T2 and PD quantification. |
| 1295 | Motion-corrected image reconstruction of abdominal DCE-MRI images | |
1Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, United States, 2Department of Radiology, University of Michigan, Ann Arbor, MI, United States, 3Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States |
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Respiratory motion of abdominal organs causes motion artifacts, blur and signal loss in DCE-MRI images which can confound liver perfusion quantification. To correct for respiratory motion a motion signal derived using rigid-body image registration was used to group acquired data from a golden-angle stack-of-stars sequence into motion states. These were then aligned using deformable image registration and the resulting deformation vector fields were used to deform complex projection images reconstructed from individual spokes. Deformed projections were finally combined using view-sharing into an image time series. The resulting portal-venous input function exhibited a higher signal enhancement and no breathing-induced intensity ripples. |
| 1296 | From Hand-Eye Calibration of Optical Tracking Cameras to Motion Correction | |
1Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, 2Department of Radiology, University Medical Center Freiburg, Freiburg, Germany |
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For motion correction using an optical tracking camera, movements must be converted from the camera reference frame to the MR reference frame. This calibration transform is determined by matching poses recorded in both reference frames. We investigated the impact that errors in one or more of these poses has on the resulting calibration. We then investigated the impact that errors in calibration has upon the apparent motion recorded. Thus we outline the necessary precision in the calibration poses to achieve motion correction of different precisions. |
| Exhibition Hall | Monday 8:15 - 10:15 |
| 1297 | Evaluation of prospective and retrospective motion correction exploiting the slice-based acquisition of fMRI | |
1Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom, 2Behavioural and Clinical Neuroscience Institute, Department of Psychology, University of Cambridge, Cambridge, United Kingdom |
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Motion artefacts are damaging to fMRI studies, masking real effects or forcing data to be discarded. Standard processing pipelines include linear registration steps between frames, though some groups proposed prospectively exploiting the slice-based nature of acquisition. The improvement this offers is rarely quantified as no “baseline” is available. Here, we simulated MRI acquisitions with a general slice-based navigation method to quantify the accuracy of prospective correction over retrospective registration. Compared to retrospective linear and non-linear techniques, registration of individual slices most accurately matched trial motion trajectories with better image quality than linear methods. |
| 1298 | Measuring the accuracy of prospective motion correction through retroactive application of estimates | |
1Neuroradiology, Karolinska University Hospital, Stockholm, Sweden, 2Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden |
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Several prospective motion correction methods have been presented to address the issue of motion induced artifacts in MRI. We present a method to determine the accuracy of prospective motion correction methods by applying estimates to a PROPELLER reconstruction. |
| 1299 | Correcting diffusion data for off-resonace effects, movement-induced signal loss and intra-volume movement. | |
1Oxford University, Oxford, United Kingdom, 2University College London |
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An intra-volume movement model was added to an existing framework for correcting off-resonance distortions, movement-induced signal dropout and subject movement in diffusion data. It was validated on highly realistic simulated data with "normal" and "high" levels of subject movement. The results show that slice-wise movement parameters can be estimated with an accuracy of ~0.2mm and ~0.2degrees for translations and rotations respectively. The simulations also show that the method substantially decreases the difference in fidelity of FA between subjects who move a lot and subjects who move a little. We finally demonstrate how the method corrects telltale signs of intra-volume movement in real data. |
| 1300 | On the importance of skin color phase variations for video measurement of cardiac activity in MRI | |
1University of Applied Sciences and Arts Dortmund, Dortmund, Germany, 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany, 3Division of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany |
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The limitations of contact-based hardware for cardiac activity measurement in MRI (e.g. electrocardiography, pulse oximetry) might eventually be overcome by using videos of the skin. Currently, a limitation for practical usage is the poor signal-to-noise ratio of the acquired signals, especially in an MR environment. We analyzed pixel intensity variations over time measured on the forehead and observed that 15%-25% of pixels exhibit a different signal morphology and phase than the remaining pixels. This effect is a limitation for many algorithms related and unrelated to MRI: If all pixels within a region-of-interest are used for averaging, different signal types are mixed which biases results. |
| 1301 | 3D Motion Estimation of Head Using Three Orthogonal Navigator Echoes and Coil Sensitivity Profiles | |
1National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States |
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Subject motion is a common source of artifact in MRI scans. Various navigator techniques have been developed to monitor motion and correct motion artifacts. In this study, a new approach was developed to extract 3D motion information of the head based on three orthogonal 1D gradient-encoded echoes acquired in about 2 ms. Complementary positional information carried by the individual sensitivity profiles of a receive array was exploited. The method was evaluated in experiments. It suggested the estimated motion parameters were within ±0.5° and ±0.5 mm accuracy in reference to co-registered head images in various positions with rotations up to ±4°. |
| 1302 | Motion-induced Magnetic Field Changes Inside the Brain | |
1National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States |
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In this study, changes of the B0 field inside the brain due to head motion were measured and analyzed. The sources contributing to this change include a static field introduced by the relative position of the head to the body and the shim coils, and a dynamic one from the head’s orientation and its susceptibility. The experimental results suggest that the component from the head and/or body has a strong magnitude and complex spatial pattern, which makes it difficult to be measured with simple navigators. This B0 field change should be properly taken into account for motion correction. |
| 1303 | High resolution free breathing abdominal imaging | |
1Philips Research Europe, Hamburg, Germany |
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The scan resolution of abdominal MR imaging using Cartesian sampling is generally limited by the breath-holding capability of the patient, as the respiratory motion would introduce ghosting artefacts. Here we show that golden-angle stack-of-stars sampling in combination with retrospective motion state binning and elastic registration enables sub millimeter in-plane scan resolutions. The technique allows the patient to breathe freely during the examination, hence improving the patient’s comfort, and simultaneously increasing the achievable scan resolution. |
| 1304 | A Comparison of Prospective Motion Correction with 19F NMR Field Probes and an Optical Camera | |
1High Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 2Institute for Microelectronics, University of Ulm, Ulm, Germany, 3Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark, 4Department of Biomedical Magnetic Resonance, University Clinic Tuebingen, Tuebingen, Germany |
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This work shows a comparison of prospective motion correction using NMR field probes and an optical tracking system in a phantom with induced motion as well as in an initial in vivo experiment. Tracking results for both systems were recorded concurrently to compare the motion estimates. The prospectively corrected images of a moving phantom and a moving human subject show a comparable correction ability for both systems. However, the lower precision of the field probe based system might prevent an application in highest-resolution imaging. |
| 1305 | Retrospective motion correction of head rotations in 2D RARE brain images using TArgeted Motion Estimation and Reduction (TAMER) | |
1A. A. Martinos Center for Biomedical Imaging, Department of Radiology, MGH, Charlestown, MA, United States, 2Graduate Program in Biophysics, Harvard University, Cambridge, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Harvard-MIT Division of Health Sciences and Technology, MIT, Cambridge, MA, United States |
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RARE/TSE/FSE imaging is the most common brain sequence, but can be severely degraded by patient motion. While 2D navigated versions (PROPELLER) and motion-tracking approaches exist, they are not widely used. We introduced a data-consistency based retrospective method, TAMER, whereby the image and motion parameters are jointly estimated by minimizing data consistency error of a SENSE+motion forward model. We employ reduced modeling techniques which assess only a few targeted voxels at each step to make the large non-linear estimation problem computationally achievable. We demonstrate the approach to mitigating rotations in phantom and human scans in addition to previously reported translation mitigation. |
| 1306 | Impact of image registration on renal T1 mapping in children with chronic kidney disease | |
1UCL Great Ormond Street Institute of Child Health, Developmental Imaging and Biophysics Section, London, United Kingdom, 2National Hospital for Neurology and Neurosurgery, Lysholm Department of Neuroradiology;, 3UCL Institute of Neurology, Department of Brain Repair and Rehabilitation |
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Renal longitudinal relaxation time (T1) is an established indicator of pathophysiological tissue status. We have applied image registration techniques to correct for motion during saturation recovery (SR) acquisitions with multiple recovery times used for T1 mapping in kidneys of paediatric patients. All registration techniques were successful in improving the intra and inter-session repeatability of the T1 estimates, as well as the quality of the underlying saturation recovery fits on a challenging patient population, as assessed by intra- and inter-scan repeatability and analysis of the root mean squared error of the SR fits. |
| 1307 | Ultrasound Monitoring of a Respiratory Phantom for the Development andValidation of Segmented EPI Reconstruction Methods | |
1Radiology, Brigham and Women's Hospital, Boston, MA, United States, 2Radiology, Massachusetts General Hospital, MA, United States, 3Harvard Medical School, Boston, MA, United States, 4Boston University, Boston, MA, United States, 5Dept. of Biomedical Engineering, Akdeniz University, Antalya, Turkey |
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In MRI, changes in lung volume can affect the static encoding field during brain imaging, inducing phase modulations in the acquired signal. In segmented EPI, these phase modulations manifest as ghost artifacts. To enable rapid development of new segmented EPI image formation methods, this work presents a respiratory phantom that can be monitored using an ultrasound transducer. Using inexpensive materials, the transducer tracks the thickness of a flexible water bottle as the respiratory phantom inflates/deflates. Results verify that phase changes induced by the changing air volume can be observed in both MR and ultrasound data, and are well correlated. |
| 1308 | Comparison of Multishot Readout-Segmented EPI and Interleaved-EPI for Motion Correction | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, People's Republic of China, 2Harvard-MIT Health Sciences and Technology, MIT, Cambridge, MA, United States |
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Readout-segmented EPI (RS-EPI) and interleaved-EPI (iEPI) are the two most widely used multishot EPI techniques for high resolution DWI. Many methods have been proposed to correct the motion-induced phase variations and rigid-motion in RS-EPI and iEPI. To compare the performance of motion correction in RS-EPI and iEPI, DWI and DTI simulations were designed. The correction methods we implemented for RS-EPI and iEPI take account of motion-induced phase variation, bulk motion and altered diffusion gradient orientation due to rotation. In our test, iEPI show less artifacts, however the b-matrix correction of RS-EPI is more straightforward with better accuracy. |
| 1309 | Readout-Segmented EPI with 2D-PACE for the Abdominal Diffusion Weighted Imaging | |
1Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, People's Republic of China |
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The 2D-PACE technique has been proved to be superior to conventional respiratory triggering techniques for imaging the abdominal region because it could detect more accurate respiratory waveform, which is already widely used in single shot EPI for high quality abdominal diffusion weighted imaging. The readout-segmented EPI features much shorter echo spacing compared with single shot EPI and consequently enjoys less distortion. In this study, the 2D-PACE technique is integrated into a readout-segmented EPI sequence and makes high resolution abdominal diffusion images with less distortion and image blurring. |
| 1310 | Unified Rigid Motion Compensation Using Wireless MR Active Markers for Simultaneous PET/MR Imaging of the Brain | |
1Engineering Physics, Tsinghua University, Beijing, People's Republic of China, 2Gordon Center for Medical Imaging, Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 3Athinoula A. Martinos Centerfor BiomedicalImaging, Radiology, Massachusetts General Hospital, Boston, MA, United States, 4Radiology and Psychiatry, Stony Brook Medicine, Stony Brook, NY, United States |
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Head motion degrades image quality through loss of resolution in brain PET/MR. This work presents a wireless MR active marker based method to track and correct head motion for both PET and MRI. The proposed rigid motion correction method has been validated using a phantom study on a clinical PET/MR scanner. |
| 1311 | Motion simulation and correction validation using MR tagging | |
1Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 2IMPRS for Cognitive and Systems Neuroscience, University of Tübingen, Tübingen, Germany, 3Biomedical engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran, 4Department of Biomedical Magnetic Resonance, University of Tübingen, Tübingen, Germany |
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Involuntary subject motion is a well-known problem in MR imaging. Motion simulation is an important step to evaluate correction performance and motion induced artifacts. Here we introduce a new approach based on MR tagging to simulate desired motion pattern on a plain phantom. We employed SPAMM method to generate grid tags with a specified orientation and position. Grid tags were rotated and shifted with a desired pattern per TR. Correspondingly, the imaging slice followed the pattern to compensate the rotation and translation of the tags. Employing this approach, we could simulate motion in 5 DOF. |
| 1312 | Repeatability and motion-invariance of Zero Echo Time bone maps | |
1GE Healthcare, Cambridge, United Kingdom, 2GE Global Research, Germany, 3GE Healthcare, United States |
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The goal of the present study was to evaluate the repeatability of a ZTE-based bone imaging method with respect to clinically realistic variations of the ideal acquisition conditions. |
| 1313 | Rapid continuous multiarterial MRI of the hepatic arterial dominant phase during free-breathing. | |
1Radiology, University Hospital Tübingen, Tübingen, Germany, 2Radiology, University Hospital Tübingen, 3Siemens Healthineers |
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Acquisition of continuous multiarterial MRI of hepatic arterial dominant phase during free-breathing using a free-breathing self-gated spoiled gradient-echo sequence with compressed sensing is feasible and yields excellent arterial enhancement with good compensation of respiratory artifacts and can improve robustness of arterial Phase liver MRI |
| 1314 | 19F imaging with physiologic motion using UTE sequence with randomized spokes ordering | |
1Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States, 2Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, United States, 3Department of Biomedical Engeneering, Salt Lake City, UT, United States, 4Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States |
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3D radial, such as ultra-short TE (UTE) MRI, is insensitive to motion-related ghosting artifact, mainly because of heavy over-sampling at the k-space origin. However, using the smooth view ordering, of which direction of the readout gradient smoothly changes, any small portion of FID data with motion-corruption tends to be clustered, while directions of random view ordering are spread out over the entire 3D surface. In this work, we will compare the artifact induced by both motion and missing lines in 3D UTE MRI for smooth and random view orderings. |
| 1315 | Application of retrospective motion correction to magnetic resonance fingerprinting | |
1IMAGO7 Research Institute, Pisa, Italy, 2IMAGO7 Research Institute, 3IRCCS Stella Maris, Pisa Italy, 4Università di Pisa, Italy |
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The image quality of MRI exams is often poor in patients that cannot lay still or are unable to follow instructions. MR Fingerprinting is a novel technique with a greatly reduced sensitivity to patient motion and a short scan time. However, its images can still have artifacts when the degree of head movement is substantial. Here, we evaluate a novel motion correction scheme for MRF. Five subjects were instructed to intentionally move their head. In post-processing an iterative motion-correction algorithm was used on the anti-aliased image frames. When using our algorithm, we observed clearer images in all subjects, indicating that our technique can further increase the motion robustness of MRF. |
| 1316 | Motion detection in spectroscopy using FID navigators | |
1Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States, 2Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 3Department of Radiology, University Hospital (CHUV), Lausanne, Switzerland, 4LTS5, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland |
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A free induction decay navigator (FIDnav) was implemented in a spectroscopic sequence to identify motion-corrupted spectra for retrospective rejection. An optimal channel combination of a weighted sum of channels based on the magnitude of a localized water reference signal allowed for improved identification of motion events. The FID navigator successfully detected motion events in both phantom studies and in vivo for both single voxel spectroscopy (SVS) and 2D chemical shift imaging (CSI). Removal of the motion-corrupted data based on the FIDnav is demonstrated to show improved spectral quality. |
| Exhibition Hall | Monday 8:15 - 10:15 |
| 1317 | Analytic description of the magnetisation phase during excitation | |
1Dept. Electrical and Computer Systems Engineering, Monash Institute of Medical Engineering, Monash University, Clayton, Australia, 2Monash Biomedical Imaging, Monash University, Clayton, Australia, 3Faculty of Medicine, Department of Neurology, JARA, RWTH Aachen University, Aachen, Germany |
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An approximate analytic expression is calculated for the phase of the transverse magnetisation during the excitation period. A spherical Bloch equation is used to find this expression. Simulation results are in agreement with the analytic solution. This analytic solution can be used where the phase information is required and, therefore, may be used to improve the performance of imaging through optimal pulse sequence design. |
| 1318 | Sheared 2DRF Excitation for Improved Off-resonance Robustness in Reduced FOV Imaging | |
1Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey, 2National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey, 3Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States |
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Reduced field-of-view (FOV) using two-dimensional spatially selective radio frequency (2DRF) excitation has been widely used for targeted, high-resolution diffusion weighted imaging (DWI). This work proposes a sheared 2DRF excitation scheme to rapidly and efficiently cover the excitation k-space. This approach not only enables extended slice coverage and preserves fat suppression capabilities, but also significantly improves the robustness against off-resonance-induced signal losses of 2DRF pulses. |
| 1319 | Double-Spoke Slab-Selective Ramp Pulse Design for UHF TOF MR Angiography | |
1CEA/DRF/I2BM/NeuroSpin/UNIRS, Gif-Sur-Yvette, France, 2Siemens Healthineers France, Saint-Denis, France, 3CEA/DRF/I2BM/NeuroSpin, Gif-Sur-Yvette, France, 4Laboratoires des Signaux et Systèmes, Université Paris-Saclay/CentraleSupélec/CNRS, Gif-sur-Yvette, France |
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Recently, the use of TOF with parallel transmission at Ultra High Field demonstrated an improvement in vessel-to-background contrast and spatial resolution. This study further investigates the in-vivo feasibility to correct for blood flow saturation effects in TOF slabs with a new double-spoke ramp pulse design optimization at 7T while mitigating in-plane TOF heterogeneities. |
| 1320 | 2D Outer Volume Suppression with T2-Preparation and Fat Saturation for Coronary Angiography | |
1Electrical Engineering, Stanford University, Stanford, CA, United States |
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A sequence for combined 2D outer volume suppression (OVS) with T2-preparation and fat saturation is proposed. This sequence provides a uniform passband robust to inhomogeneities, significantly lower SAR than existing methods, and flexibility to be used as a standalone OVS sequence. Numerical simulation and phantom results verify the sequence in theory and in vivo results corroborate the performance in practice. |
| 1321 | An Efficient Minimum-Time VERSE Algorithm | |
1GE Healthcare, Waukesha, WI, United States |
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A computationally-efficient constrained minimum-time VERSE algorithm is presented which is sufficiently fast that it could be used for real time VERSE’ing of RF pulses during pulse sequence prescription. |
| 1322 | Selective excitation using Multix and Active contouR Technique | |
1Medical Imaging Research Centre, Dayananda Sagar Institutions, Bangalore, India, 2Philips Innovation Campus, Bangalore, India |
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Selective excitation using Multix and Active contouR Technique (SMART) proposed here, is an optimization framework for the joint design of k-space trajectories and radio frequency pulses. The combination of active contour and the multix has been done for the first time which allows the use of arbitrary k-space trajectories. SMART has been prospectively implemented on two channel 3T Philips Ingenia system for different geometric shapes and organs to demonstrate arbitrary volume selective excitation and has shown improved excitation profile. Current and future work involves implementation on in-vivo studies. |
| 1323 | The Effect of RF Exposure Duration in RF Pulse Design Using Temperature Constraints | |
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, 2The Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY, United States |
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There is an increasing interest in using temperature to ensure safety in MRI. We designed parallel transmission RF pulses using either SAR or temperature constraints and compared to each other and unconstrained RF pulse design in terms of excitation fidelity and safety for four different RF exposure durations (from 6 mins to 24 mins). We found that the benefit of using temperature correlation matrices on RF pulse design diminishes as RF exposure duration increases. However, safety of the subject is always guaranteed (the maximum temperature was equal to 39°C). This trend was observed in both head and hip regions, where the perfusion rates are very different. |
| 1324 | RF pulse design by optimal control with physical constraints | |
1Institute for Mathematics and Scientific Computing, University of Graz, Graz, Austria, 2BioTechMed Graz, Graz, Austria, 3Institute of Medical Engineering, Graz University of Technology, Graz, Austria |
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The design of customized RF pulse and slice selective gradient shapes gives rise to an optimal control problem for the Bloch equation with different inequality constraints. A state-of-the-art method of optimal control is designed especially for this problem class. The optimization model and method is applied to recent test examples. The results are validated on a 3T scanner with phantom and in vivo measurements. |
| 1325 | Combined flip angle and echo scaling modulation for optimal fast spin echo | |
1Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States |
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Fast spin echo acquisition plays an essential role in a worthy of MRI applications. But the flip angles of refocus pulses are conventionally designed intuitively. In this work, we proposed a global scheme that can provide a comprehensive framework for flip angled design and proposed the requirement with a well-proposed optimization problem. The performance of the proposed method was demonstrated on the correction of T2 blurring with numerical simulation. |
| 1326 | Local SAR minimization of Turbo Spin-Echo sequences by Dynamic RF Shimming | |
1UMC Utrecht, Utrecht, Netherlands, 2King's College London |
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Turbo Spin-Echo sequences (TSE) are frequently characterized by high local specific absorption rate (SAR), a limiting factor for their application. Here we show that the direct signal control (DSC) framework can drastically reduce the local SAR response of a TSE sequence by expanding the search-space for the amplitude and phase RF weights. A solution is found which enforces optimal contrast behavior and local SAR limits across different shim settings. A cardiac exam at 3 Tesla MRI is used as simulated test case. |
| 1327 | Squeezed Variable Density Spiral Trajectory for SAR Reduction in Parallel Transmission 2D RF Design | |
1Center for Brain Imaging Science and Technology, Department of Biomedical Engineering, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China |
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A squeezed variable density spiral (SVDS) trajectory was proposed to reduce SAR and peak RF power in 2D RF pulse design using parallel transmission (pTX). SVDS was generated by applying a pointwise squeezing factor to conventional variable density spiral (CVDS) trajectory. Compared to CVDS, SVDS can reduce peak RF and SAR by close to 40%, with minimal increase in the normalized root mean square error (NRMSE) of the excitation profile and pulse duration. |
| 1328 | New method to characterize and correct with sub-µs precision gradient delays in bipolar multi-spoke RF pulses | |
1UNIRS, CEA/DRF/I2BM/Neurospin, Gif-sur-Yvette, France, 2Siemens Healthcare, Saint Denis, France |
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Small gradient delays with respect to radiofrequency (RF) pulses can have disastrous effects on the performance of bipolar spokes RF pulses employed in parallel transmission (pTx) to mitigate RF field inhomogeneity problems. This work reports a new method to characterize this delay with a precision of ~20 ns, shown to appear necessary for high performance pTx. By the same token, the same physics principles underlying the method suggest a way to correct for it by simply phase-shifting every second spoke RF pulse. The technique is validated with measurements on a water phantom and on an adult volunteer at 7T. |
| 1329 | Validation of the universal pulse concept at 7 Tesla on the Nova 8Tx/32Rx head coil with parallel transmit kT-point RF pulses | |
1UNIRS, CEA/DRF/I2BM/Neurospin, Gif-sur-Yvette, France, 2Siemens Healthcare, Saint Denis, France, 3DZNE, Bonn, Germany |
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At ultra-high field, the use of parallel transmit (pTx) kT-point RF pulses can greatly improve the excitation uniformity of non-selective radiofrequency pulses but this approach generally requires additional pre-scans to map subject-specific transmit field sensitivities and compute optimal waveforms thereupon. Alternatively, quasi-optimal RF pulses can be obtained by replacing subject-specific field maps by a so-called field database resulting from the accumulation of field maps acquired in a small cohort. This concept is validated here at 7 Tesla on the Nova 8Tx/32Rx head coil with the implementation of a MP-RAGE protocol integrating universal kT-point pTx pulses. |
| 1330 | Probabilistic analysis of the SAR intersubject variability safety factor in parallel transmission MRI | |
1DRF/I2BM/NeuroSpin, CEA, Gif sur Yvette, France, 2DRF/Irfu/SACM, CEA, Gif sur Yvette, France |
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Electromagnetic simulations remain to date the preferred method to assess the Specific Absorption Rate (SAR). Within that framework, taking into account the SAR intersubject variability by using a multiplicative safety factor on generic model results remains attractive due to its computational simplicity. Here we report a probabilistic analysis based on the unscented transform sampling scheme followed by the reconstruction of a polynomial approximation of the SAR with respect to head geometrical and position variables. Probabilities of exceeding a given SAR value in the population are returned and safety factors can be deduced based on risk over benefit ratio assessments. |
| 1331 | B1+ maps intersubject variability study for universal pulses applications in parallel transmission MRI | |
1DRF/I2BM/NeuroSpin, CEA, Gif sur Yvette, France, 2DRF/Irfu/SACM, CEA, Gif sur Yvette, France |
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Despite its power to mitigate B1+-inhomogeneity, subject-specific tailored parallel transmission (pTx) suffers from a cumbersome workflow involving measurement of field maps as well as online pulse design. Recently however, it was shown that RF inhomogeneity-mitigating (universal) pulses could be found offline to work robustly over a given B1+ maps-database, thus potentially sparing the user the time-consuming calibration. To gain further performance with improved database matching for universal pulses, in this work we investigate with electromagnetic simulations the intersubject B1+ map variability by systematically varying position (in Z and Y), head length and head breadth of a reference head model. |
| Exhibition Hall | Monday 8:15 - 10:15 |
| 1332 | Water and Fat Based Partial Volume Correction for PET/MRI | |
1Radiology, University of Wisconsin, MADISON, WI, United States, 2Electrical Engineering, University of Wisconsin, MADISON, WI, United States, 3University of Wisconsin, MADISON, WI, United States |
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In this study we propose to develop methods that improve the resolution of PET images by utilizing water and fat-based partial volume correction. These methods are expected to be particularly useful in simultaneous breast PET/MR imaging as white adipose tissue is known to be minimally FDG avid. |
| 1333 | Simultaneous Estimation of ADC, T2-relaxation, Perfusion and 11C-acetate PET Uptake in Prostate Cancer | |
1Department of Radiation Sciences, Umeå University, Umeå, Sweden, 2Department of Radiology, Uppsala, Sweden, 3Healthcare Systems, GE Healthcare, Stockholm, Sweden, 4Applied Science Laboratory, GE Healthcare, Uppsala, Sweden |
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Multiparametric MRI is the standard to evaluate suspected prostate cancer. T2-weighted and DWI are essential, while DCE is less crucial. We here demonstrate that simultaneous quantification of ADC, T2-relaxation and perfusion fraction f, which was calculated from non-IVIM low b-value data, is feasible in combination with 11C-acetate PET/MR imaging. ADC and T2-values differed significantly between healthy tissue and cancer, while f was more inconsistent. An important benefit of simultaneous acquisition is the lack of image mismatch between T2-maps and DWI. This enables more objective tumor grading, decreased inter-rater variability and using mathematical/statistical approaches or computer-aided detection to estimate cancer probability. |
| 1334 | Zero-echo-time PET/MRI attenuation correction shows good correlation between 15O-water PET and simultaneously acquired ASL in standard regional flow territories | |
1Surgical Sciences, Uppsala University, Uppsala, Sweden, 2Biomedical Technology, Medical Physics and IT, Uppsala University Hospital, Uppsala University Hospital, Uppsala, Sweden, 3Applied Science Laboratory, GE Healthcare, Uppsala, Sweden, 4Medicinal Chemistry, Uppsala University, Uppsala, Sweden, 5Neuroscience, Uppsala University, Uppsala, Sweden |
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Zero-Echo-Time (ZTE) MRI for attenuation correction (AC) in hybrid PET/MRI-systems is a promising method. This study aims to examine reproducibility between 15O-water PET and simultaneously acquired Arterial Spin Labelling (ASL) using ZTE-MRI AC and the reproducibility between to subsequent ASL measurements. Measurements were performed on six subjects on an integrated 3.0 T PET/MRI-system. Regional cerebral blood flow (CBF) values from standard flow territories were compared. ASL showed good correlation with 15O-water PET, presenting another advantage of ZTE-MRI AC. A significant decrease between ASL measurements was detected, which may be important to consider when designing PET/MRI-studies. |
| 1335 | Hybrid ZTE/Dixon MR-based Attenuation Correction for Knee PET/MR Sodium Fluoride Studies | |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 2GE Global Research, Munich, Germany, 3GE Healthcare, Waukesha, WI, United States |
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This study introduces a new hybrid ZTE/Dixon MR-based attenuation correction (MRAC) method including bone density estimation for PET/MRI and quantifies the effect of bone attenuation on sodium fluoride uptake in the knee. |
| 1336 | Impact of new attenuation correction methods on whole-body PET/MR | |
1High Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany, 2Erwin L. Hahn Institute for MR Imaging, University Duisburg-Essen, 3Department of Nuclear Medicine, University Hospital Essen, 4Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, 5Siemens Heathineers, Siemens AG, Erlangen, Germany |
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Recent developments in MR-based whole-body PET/MR attenuation correction allow for adding bone information and for eliminating truncation artefacts along the patients’ arms using the HUGE technique. 43 patients underwent a PET/MR whole-body examination. The PET SUVmax of 57 active lesions were measured for PET data reconstructed with four different µmaps: standard, standard+bone, standard+HUGE, and standard+bone+HUGE. Compared to the standard-µmap, the mean SUVmax of all 57 lesions increases by 14%±12% when adding bone, by 17%±12% when adding HUGE, and by 24%±19% when adding bone+HUGE. These results are an important step towards improved MR-based attenuation correction in whole-body PET/MR hybrid imaging. |
| 1337 | Comparison of UTE-based Attenuation Correction Methods for Simultaneous PET/MR Imaging of the Children's Brain | |
1Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China, 2Department of Nuclear Medicine, Chinese PLA General Hospital, People's Republic of China, 3Key Laboratory of Particle and Radiation Imaging, Ministry of Education, Medical Physics and Engineering Institute, Tsinghua University, Beijing, People's Republic of China |
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In simultaneous PET/MR imaging, PET attenuation correction is based on MRI, unlike PET/CT systems, which directly use CT measurements. Various approaches have been developed based on templates, atlas information, direct segmentation of T1-weighted MR images. In the present study, we introduced two approaches of UTE-based attenuation correction for simultaneous PET/MR imaging focusing on children’s brain, including segmentation-based method and Support Vector Machine (SVM) regression method. The results have been compared with Gaussian Mixture Regression (GMR) model method. |
| 1338 | A Non-invasive Method for Quantifying Cerebral Blood Flow by Hybrid PET/MR | |
1Lawson Health Research Institute, London, ON, Canada, 2Medical Biophysics, Western University, London, ON, Canada |
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While PET with [15O]H2O is the gold standard for imaging CBF, quantification requires measuring the arterial input function (AIF), which is an invasive and noisy procedure. ASL is an attractive alternative, however, its accuracy is limited by low SNR. Considering these limitations, we propose a hybrid PET/MRI approach using global CBF measurements from phase contrast MRI to convert [15O]H2O PET data into CBF maps. To test this method, using a large animal model, CBF was measured by this hybrid approach and by PET only, where the AIF was measured. Good agreement was found over a CBF range (20-100 ml/100g/min). |
| 1339 | Effects of B1 Correction on the Accuracy of T1, T2 and ADC Values Measured with a Diffusion-Weighted Dual-Echo Steady-State (DW-DESS) Sequence | |
1Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 2Medical Imaging, University of Toronto, Toronto, ON, Canada |
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Diffusion-weighted dual-echo steady-state (DW-DESS) imaging allows multiple MR parameters to be quantified without image distortion. In this work, we investigate the effects of B1 correction on the accuracy of T1, T2 and ADC parameters estimated from DW-DESS. We extend the quantification to species with ADC and T2 values that are similar human cancers by using a novel phantom mixture. The accuracy of parameter estimates measured with DW-DESS is improved after B1 correction, with correlation coefficients of 0.912, 0.997 and 0.778 without B1 correction to 0.993, 0.998 and 0.947 after B1 correction (for T1, T2 and ADC, respectively). |
| 1340 | Improved clinical workflow for simultaneous whole-body PET/MRI using high-resolution CAIPIRINHA-accelerated MR-based attenuation correction | |
1Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Siemens Healthineers, Erlangen, Germany, 3Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 4Divison of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Germany, 5Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center (DKFZ), Heidelberg, Germany, 6Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany, 7Junior Group Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany |
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The present study assesses the value and reproducibility of a novel CAIPIRINHA-accelerated T1-weighted Dixon-based prototype for whole-body PET/MRI in comparison to the clinical standard. This prototype allows the aquisition of an MR-based attenuation correction and a high-resolution T1w DIXON stack that may be used for diagnostic correlation of PET findings in one single step. Voxel-wise intra-individual differences, intermethod-agreement using regression and bland-altman plot analysis, inter-reader agreement for image quality and a repeated measurement experiment in a healthy volunteer without tracer injection were peformed. The novel prototype demonstrated a high reproducibility of standardized uptake value quantification compared to the standard and excellent image quality for all body regions. Smaller breathing artifacts in the lungs may transfer on the PET µmap and thus influence the attenuation correction. Therefore, physicians and the technicians need to assess the µmap to veriy artifact-free acquisition. The novel protoype is useful for clinical PET/MRI studies towards time-efficient protocols as a separate T1w-sequence may be omitted. |
| 1341 | Preliminary Clinical Experience with FDG-PET/MRI in Plasma Cell Dyscrasias | |
1Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO, United States |
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Multiple |
| 1342 | Application of MR-based truncation correction (HUGE) in whole-body PET/MR hybrid imaging | |
1University Hospital Essen, Essen, Germany, 2Siemens Healthcare GmbH, 3Erwin L. Hahn Institute for Magnetic Resonance Imaging |
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In quantitative PET-imaging, it is essential to correct for the attenuation of photons in tissue. In combined PET/MR-imaging the attenuation correction (AC) is based on MR-data and subsequent tissue class segmentation. The MR-FOV is limited due to B0-inhomogeneities and gradient nonlinearities. Therefore, the AC-map is truncated and reconstructed PET-data are biased. HUGE (B0-Homogenization using gradient enhancement), which determines an optimal readout gradient to compensate gradient nonlinearities, was applied in whole-body PET/MR examinations of 24 oncologic patients. The extension of the MR-FOV for MR-based AC showed an improvement of PET-quantification in integrated PET/MR-imaging by reducing the truncated areas of the AC-map. |
| 1343 | 3D Printed Phantom for PETMR Attenuation Correction | |
1Radiology and Biomedical Imaging, UCSF Medical Center, San Francisco, CA, United States |
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This experiment sought to explore PET/MRI attenuation correction with a 3D printed skull phantom used to mimic bone attenuation and MR characteristics. |
| 1344 | Optimal MRI sequences for 68Ga-PSMA-11 PET/MRI in evaluation of biochemically recurrent prostate cancer | |
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, 2Urology, UCSF, San Francisco, CA, United States, 3Medicine, Division of Hematology and Oncology, UCSF, San Francisco, CA, United States |
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On 68Ga-PSMA-11 PET/MRI for biochemically recurrent prostate cancer, small PSMA-positive lesions are detected on some, but not all MRI sequences. To determine the most effective sequences to obtain for a 68Ga-PSMA-11 PET/MRI protocol, the sensitivities of small FOV T2, T1 post-contrast, and diffusion-weighted sequences for identification of small abdominopelvic nodes were evaluated. In addition, multiphasic contrast-enhanced Differential Subsampling with Cartesian Ordering (DISCO) images were evaluated for detection of prostate bed recurrence. Examination of 48 consecutive patients indicates that small FOV T2 images are most sensitive for small abdominopelvic nodes and DISCO images are most sensitive for prostate bed recurrence. |
| 1345 | T1 and T2 mapping using highly accelerated radial data acquisition and alternating direction method of multipliers | |
1Electrical and Computer Engineering, University of Arizona, Tucson, AZ, United States, 2Department of Medical Imaging, University of Arizona, Tucson, AZ, United States, 3Biomedical Engineering, University of Arizona, Tucson, AZ, United States |
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Quantitative MRI requires accurate parameter estimation but long acquisition time limits the use of conventional techniques in the clinic. Recently, several T1 and T2 mapping methods based on highly accelerated radial trajectories have been proposed. The reconstruction problems in these works are formulated as unconstrained optimizations and solved using the non-linear conjugate gradient method. We propose an alternative formulation based on the alternating direction method of multipliers which reduces reconstruction time without compromising reconstruction quality. |
| 1346 | Eye Tracking System for Prostate Cancer Diagnosis Using Multi-Parametric MRI | |
1Clinical Center, National Institutes of Health, Bethesda, MD, United States, 2SZI, Children's National Health System, Washington, DC, United States, 3Pediatrics, George Washington University, Washington, DC, United States, 4NCI, National Institutes of Health, Bethesda, MD, United States, 5CIT, National Institutes of Health, Bethesda, MD, United States, 6Center for Research in Computer Vision, University of Central Florida, Orlando, FL, United States |
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Medical images have been studied using eye tracker systems from visual search and perception perspectives since 1960’s. However number of studies for the multi slice imaging is very limited due to the technical challenges. We developed a software to overcome the difficulties, and enable visual search/perception studies using multi-parametric MRI of prostate cancer. Multiparametric MR images (T2w, DWI, ADC map, and DCE) were synchronized with the eye tracker system and visual-attention maps were successfully created for each image types using gaze information. This is the first multiparametric MR study using an eye tracker system. |
| 1347 | A Constrained Least Squares Approach to MR Image Fusion | |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Mathematics, California State University in Northridge, Northridge, CA, United States |
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Fusing a lower resolution color image with a higher resolution monochrome image is a common practice in medical imaging. By incorporating spatial context and/or improving the Signal-to-Noise ratio, the fused image provides clinicians with a single frame of the most complete diagnostic information. In this paper, image fusion is formulated as a convex optimization problem which avoids image decomposition and permits operations at the pixel level. This results in a highly efficient and embarrassingly parallelizable algorithm based on widely available robust and simple numerical methods that realizes the fused image as the global minimizer of the convex optimization problem. |
| 1348 | A Comparison of Optimised Single-Shot MR Fingerprinting Pulse Sequence Designs. | |
1FMRIB, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, United Kingdom, 2Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom |
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The parameter mapping accuracy of MR Fingerprinting (MRF) relies on specific signal patterns for each set of parameters. Choice of sequence design and acquisition parameters are two aspects that affect this. We optimised the TR and Flip Angle (FA) of a selection of simulated single-shot MRF designs, based on Inversion-Recovery Gradient Echo (IR-GRE), GRE, Spin Echo (SE) and IR-SE sequences. We compared the parameter assignment accuracy of each optimised design. Our results suggest that GRE-based sequences should be used for single-shot MRF. |
| 1349 | First results from an MRI compatible small animal PET insert operating in a clinical 3T PET/MRI | |
1Imaging Program, Lawson Health Research Institute, London, ON, Canada, 2Department of Medical Biophysics, University of Western Ontario, London, ON, Canada, 3Cubresa, Winnipeg, MB, Canada, 4National Research Council of Canada, Winnipeg, MB, Canada, 5Department of Radiology, University of Manitoba, Winnipeg, MB, Canada, 6Department of Physics and Astronomy, University of Manitoba, 7PET/CT Imaging Program, Section of Nuclear Medicine, Health Sciences Centre, Winnipeg, MB, Canada |
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Reaching sub-millimeter limits in spatial resolution and improved temporal resolution, simultaneous PET/MRI using a pre-clinical MR compatible PET insert enables new discoveries in science and medicine. We recently evaluated a versatile MR compatible small animal PET insert in collaboration with Cubresa. Presented here are the first simultaneous images obtained using both imaging modes within our clinical 3T MRI. |
| 1350 | Quality Factors for Efficient and Precise MRF Imaging | |
1Physics, Case Western Reserve University, Cleveland, OH, United States, 2Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 3Radiology, University Hospitals Case Medical Center, Cleveland, OH, United States |
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With the invention of MRF imaging, there is considerable freedom in input parameter selection, but it is difficult to determine how each choice affects the resulting parameter maps. Quality factors are introduced as a means of comparing MRF sequences with various input parameters (FA, TR, TE, N) on their abilities to precisely quantify T1 and T2. Simulations, fully sampled, and undersampled experiments verified that sequences with higher quality factors result in lower standard deviations in R1 and R2. With quality factor analysis, researchers and clinicians can readily determine the appropriate MRF input parameters to image more efficiently and precisely. |
| 1351 | Cross-Modality MR Image Reconstruction: CT-Constrained Anisotropic Diffusion to Preserve Edge Information in MRI of an Ancient Mummified Hand | |
1Dept. of Radiology, Medical Physics, Medical Center – University of Freiburg, Freiburg, Germany, 2Institute of Evolutionary Medicine, Medical Faculty, University of Zürich, Zürich, Switzerland |
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Constrained reconstruction is making use of additional image information to improve the precision in the reconstruction of undersampled MR data. Here we use co-registered CT-data as an anisotropic diffusion constraint to improve sharpness in short T2* images reconstructed from undersampled 3D UTE data of a mummified human hand. The results are compared to other established reconstruction methods. |
| 1352 | Contrast matching of ultra-high resolution minimum deformation averaged MRI models to facilitate computation of a multi-modal model of the human brain | |
1Centre for Advanced Imaging, University of Queensland, Brisbane, Australia, 2Department of Health Science and Technology, Aalborg University, Aalborg, Denmark |
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A contrast matching algorithm was developed to enable non-linear coregistration of multi-modal minimum deformation averaged MRI models using cross correlation. The registration results show that the contrast conversion enables non-linear multi-modal coregistration. |
| 1353 | Fast Analytical Solution for Extreme Unaliasing of MR Fingerprinting Image Series | |
1Imaging Division, The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 2Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 3Radiology, Case Western Reserve University & University Hospitals, Cleveland, OH, United States |
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A non-iterative analytical solution to the MRF image reconstruction problem is presented. The method performs a direct interpolation of the acquired k-space points based on a singular-vector basis of fingerprints from a first-pass MRF estimate. The method is shown to drastically reduce spatio-temporal aliasing, allowing accurate T1 and T2 measurements for a single slice with a 7.6s acquisition, without need for auto-calibration data, and with computational overhead an order of magnitude faster than previously reported iterative image-based methods. |
| 1354 | Removing the estimation bias due to the noise floor in multi-parameter maps | |
1WIAS, Berlin, Germany, 2Emory University, Atlanta, USA, 3Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, London, United Kingdom, 4Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, Leipzig, Germany, 5Department of Systems Neuroscience, Medical Center Hamburg-Eppendorf, Hamburg, Germany |
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We demonstrate the bias effect due to the low signal-to-noise ratio of ultra-high resolution (0.5μm isotropic) Multi-Parameter Mapping acquisitions of quantitative R1, R2* and PD maps and develop a method for improved parameter estimation. |
| 1355 | Analyzing the Bayesian Approach to Partial Volume in Magnetic Resonance Fingerprinting | |
1Radiology, Case Western Reserve University, Cleveland, OH, United States, 2Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States |
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We present work to optimize the parameters used in the Bayesian approach to partial volume in MRF. Care needs to be taken when choosing parameter values to balance effects from noise and over regularization of the solution. MRF brain data from a normal volunteer is analyzed to determine the optimal parameters in separating white matter from gray matter and gray matter from CSF. Parameter choices are confirmed by examining the results from our algorithm in regions of pure white matter. |
| 1356 | Accelerated Magnetic Resonance Fingerprinting Reconstruction using Majorization-Minimization | |
1Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, 2Department of Diagnostic Radiology, The University of Hong Kong, Pokfulam, Hong Kong, 3The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong |
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Magnetic resonance fingerprinting (MRF) is a novel and efficient method for the estimation of MR parameters, such as off-resonance (DB0), proton density (PD), T1 and T2. Because of the highly undersampled readout that is conventionally used, large number of dynamics (e.g. <1000) are often acquired for maintaining the fidelity of MR parameter estimations (a.k.a. dictionary matching). In this study, we propose a new algorithm, MRF reconstruction using majorization-minimization (mmMRF), such that fidelity of dictionary matching can remain similar even when significantly less number of dynamics are available. |
| 1357 | Toward an Optimized Dictionary for Pattern Matching in Magnetic Resonance Fingerprinting | |
1Dept. of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Dept. of Radiology, University Hospitals of Cleveland, Cleveland, OH, United States |
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An important issue in magnetic resonance fingerprinting (MRF) is the precision of pattern matching. The sensitivity of inner product between the signal and dictionary can be corrupted by closely spaced dictionary entries. In order to make MRF more sensitive and precise, four modifications of the MRF dictionary are proposed. The performance of each method is tested and compared over 30 repetitions in a phantom scan. Some of the methods demonstrate a significant reduction in the error over the original MRF dictionary. |
| 1358 | Proton Density Mapping and Receiver Bias Correction for Absolute Quantification with 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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MR Fingerprinting (MRF) can simultaneously map multiple parameters and can be used to compute estimates of tissue fractions. However, MRF-derived M0 maps contain information about both proton density (PD) and the receiver sensitivity profile (RP). Here we estimate relative PD and RP from MRF M0 and T1 maps. Relative PD and tissue fractions are combined for absolute quantity mapping of CSF, gray matter, and white matter as a fraction of the voxel equilibrium magnetization. |
| 1359 | In vivo MR blood oximetry based on $$$T_2$$$-prepared bSSFP | |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, PA, United States |
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To develop in vivo MR oximetry based on T2-prepared bSSFP constant refocusing-pulse interval ($$$\tau_{180}$$$) T2-preparation, three-parameter signal fitting for T2 extraction and magnetization reset for shortened pulse sequence cycle were implemented and evaluated against a multi-spin echo sequence using static and flowing MnCl2 solutions with known T2 values. The whole-blood T2 was also quantified to investigate the effect of varying . The phantom results support three-parameter fitting, and <5% error incurred in T2 quantification with shortened T2-preparation cycle and presence of constant flow. Approximately 10% longer whole-blood T2 was observed with constant relative to varying . |
| 1360 | Comparison of Renal R2* Analysis Methods | |
1Dept. of Radiology, Medical Physics, Medical Center - University of Freiburg, Germany, Freiburg, Germany, 2Medical Center - University of Freiburg, Germany |
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BOLD MRI can be applied as an indirect measure of the oxygenation level changes in the kidneys while performing an experiment with a functional renal challenge. These changes are detected by the relaxation rate R2* in the renal cortex and medulla. For R2* analysis different methods are proposed, such as the conventional manual ROI method and a compartmental method. Here, these methods and two further compartmental methods are compared to each other by analyzing full time-resolved renal BOLD MR experiments in healthy volunteers. |
| 1361 | Development of contrast agents for simultaneous PET/MRI of murine tumor models | |
1University of Arizona, Tucson, AZ, United States, 2Pharmaceutical Sciences, University of Arizona, Tucson, AZ, United States, 3Medical Imaging, University of Arizona, Tucson, AZ, United States |
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PET/MRI contrast agents represent a new field of molecular imaging that provide an outstanding opportunity to employ simultaneous PET/MRI instrumentation for quantitative imaging. Over 90 responsive MRI contrast agents have been reported that change their contrast based on a biomarker and agent concentration, limiting their utility in vivo because a change in signal could arise from the presence of the biomarker and/or a change in the concentration of the agent. We propose to use PET to quantify the agent concentration, and a comparison of PET and MRI contrast can quantitatively evaluate the biomarker in a concentration-independent manner. Herein we describe the synthesis and characterization of 18F-radiolabeled responsive MRI contrast agents that are designed to measure pH and redox state using simultaneous PET/MRI for small animal studies. |
| 1362 | STEAM-CPMG: A method for localized Pulsed-Field-Gradient-Stimulated-Echo CPMG acquisitions | |
1Institute of Myologie, La Pitié-Salpêtrière University Hospital, Paris, France, 2CEA/DRF/I2BM/MIRCen, Fontenay aux Roses, France, 3Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland, 4Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland |
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The CPMG method has been long applied for multi-component T2 studies which have been shown to reveal the micro-anatomical compartmentation of water in biological tissue. A new method for localized CPMG acquisitions that makes use of the Stimulated Echo Acquisition Mode technique is presented. Besides offering localized T2-relaxation data within less than 10 s, the method is suited for performing Diffusion-Relaxation-Correlation-Spectroscopy studies. Such studies allow evaluating the translational diffusion of the different T2-compartments observed in vivo and shall offer new insights on diffusion and relaxation processes in biological tissues. The method has been validated in vitro. |
| 1363 | Early changes of irradiated parotid glands evaluated by T1rho-weighted imaging: a pilot study | |
1Department of Radiology, Drum Tower Hospital, School of Medicine, Nanjing University, Nanjing, People's Republic of China, 2Department of Radiology, Drum Tower Hospital, School of Medicine, Nanjing University, 3Philips Healthcare, Shanghai, People's Republic of China |
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Twenty-six NPC patients underwent serial T1rho-weighted imaging to evaluate the dynamic changes of parotid glands in patients undergoing intensity-modulated radiation therapy. Parotid volumes, T1rho values, mean radiation doses, and xerostomia degrees were recorded. Change rates of T1rho values were correlated with atrophy rates, mean radiation doses and xerostomia degrees. During RT, parotid volume decreased and parotid T1rho values increased significantly. The change rate of T1rho value correlated with the atrophy rate significantly at post-RT. Intra- and interobserver reproducibility of T1rho measurements were excellent. Dynamic changes of radiation-induced parotid damage in NPC patients underwent IMRT could be evaluated by T1rho-weighted imaging. |
| 1364 | A short protocol for determining apparent kurtosis validated in a hybrid MR-PET clinical environment | |
1INM-4, Research Centre Jülich, Jülich, Germany, 2Instituto de Biofísica e Engenharia Biomédica, Sciences Faculty, University of Lisbon, Lisbon, Portugal |
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Mean kurtosis (MK) obtained from the kurtosis tensor is often associated with acquisition protocols that may be long for clinical demands. Apparent kurtosis (Kapp), obtained from the direct fit of the signal to an exponential decay, is faster to acquire and may provide with similar information. Directional averaging is required to preserve spherical invariance; however, in clinical applications the trace of diffusion tensor measured with 3 directions is often used as tissue marker with good results. In this study we investigate Kapp derived from trace data in forty brain tumour patients and compare it to mean kurtosis. Kapp was found to be underestimated but the two metrics show a significantly high degree of correlation. |
| 1365 | 68Ga-PSMA dose reduction for imaging the pelvic region with simultaneous PET/MR | |
1Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland, 2University of Zurich, Zurich, Switzerland, 3GE Healthcare, Waukesha, WI, United States |
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When performing simultaneous single station PET and MR scans in the pelvic region, the PET acquisition time could be increased to match the usually more extensive MR protocol acquisition time. The gain in detected coincidences could be applied to decrease the PET tracer dose and thus the patient’s radiation burden, while maintaining the same image quality. In this study we investigate the minimal 68Ga-PSMA dose for a 15-minute single station PET(/MR) scan to match image quality of the standard 2 minutes scan at full dose. |
| 1366 | Comparison of Myelin Water Fractions from Multi-Echo Spin-Echo and Multi-Gradient Echo Techniques | |
1McGill University, Montreal, QC, Canada, 2Research Institute, McGill University Health Centre, Montreal, QC, Canada, 3University of Calgary, Calgary, AB, Canada |
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Myelin Water Fraction (MWF) imaging is typically achieved using a Multi-Echo Spin-Echo (MESE) sequence that has a long acquisition time. The Multi-Gradient Recalled Echo (MGRE) |
| Exhibition Hall | Monday 8:15 - 10:15 |
| 1367 | High Resolution 3D GRE Brain MR Elastography is Feasible with a High Performance Compact 3T Scanner | |
1Radiology, Mayo Clinic, Rochester, MN, United States |
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Several groups have investigated the role of magnetic resonance elastography (MRE) for the diagnosis of neurological diseases, which has primarily been done using 2D imaging acquisitions. The objective of this study is to determine if 3D FGRE MRE can localize small regions of elevated stiffness for brain MRE applications on a high performance compact 3T head only scanner. This study demonstrated that a compact 3T scanner has sufficient gradient performance to successfully acquire high resolution 3D FGRE MRE exams, and localize inclusions as small as 1.75cm in diameter, which is not possible on a conventional 3T scanner. |
| 1368 | Robust MR elastography stiffness quantification using a localized divergence free finite element reconstruction | |
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom |
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The increasing use of MR elastography demands that fast, robust, and out-of-the-box reconstruction methods are available. A new local direct method is presented here to fit these needs. The method utilizes the finite element method, assumes that stiffness is locally homogeneous, and includes additional advancements that improve quality and robustness. Efficacy of the proposed method is demonstrated across phantoms and volunteer data in the brain and breast. The method is contrasted with other standard techniques, showing similar or improved accuracy and robustness, improved computational cost and an independence from regularization parameters. |
| 1369 | A novel MR Elastography transducer concept based on a rotational eccentric mass: the gravitational transducer | |
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 2Radiology, Academic Medical Center, Amsterdam, Netherlands, 3Biomedical NMR, Eindhoven University of Technology, Eindhoven, Netherlands, 4Preclinical and Translational MRI, Academic Medical Center, Amsterdam, Netherlands |
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Several transducer designs are in use for MR Elastography, based mainly on either pneumatic (or compressed) air or on electromagnetic engine-coils fixed to a lamella. These technologies have enabled significant development within the MR Elastography community and shaped its clinical application. In this abstract, we build on these concepts to introduce a novel transducer that limits image artefacts, limits resonant frequencies and vibrational impurities, and importantly preserves transducer amplitude with frequency; effectively improving the quality of the wave data that can be encoded with MR. |
| 1370 | Fast Magnetic Resonance Elastography using a DENSE approach with Multi Phase Offset Readout | |
1Department of Neurology, Medical University of Graz, Graz, Austria |
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In MRE, motion encoded phase images are acquired to calculate mechanical tissue parameters based on shear wave propagation. We here propose a fast multi readout MRE imaging concept based on the displacement encoding via stimulated echo acquisition (DENSE). In this proof of concept study, phantom experiments yielded excellent clear wave images. The results indicate that the proposed technique could be used to acquire images using short echo times and accelerate the total acquisition time of MRE examinations. |
| 1371 | Reproducibility Study of Direct and Non-Linear Inversion High-Resolution Magnetic Resonance Elastography (MRE) of the Hippocampus | |
1Alzheimer Scotland Dementia Research Centre, University of Edinburgh, Edinburgh, United Kingdom, 2Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, United Kingdom, 3Department of Biomedical Engineering, University of Delaware, 4Thayer School of Engineering, Dartmouth College, 5Department of Biomedical Engineering, Columbia University, 6Institute for Medical Informatics, Charité Universitätsmedizin Berlin, 7Department of Radiology, Mayo Clinic |
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Certain neurological disorders may not be detected with current clinical imaging modalities. Magnetic Resonance Elastography (MRE) combines acoustics with MRI to provide maps of tissue mechanical properties and may be sensitive to subtle tissue pathologies. Two published approaches for performing high-resolution MRE (so-called Direct Inversion and Non-Linear inversion) were applied to enable comparison of test-retest reproducibility of the hippocampus. Intraclass correlation coefficient found DI and NLI to display fair (0.42) and excellent (0.95) reproducibility, respectively, for measuring the magnitude of the complex shear modulus |G*|. Future work will assess the relative magnitude of technical and biological variance including both sex and ageing effects. |
| 1372 | Anisotropic shear modulus estimation in ex vivo white matter of the brain using magnetic resonance elastography and finite element modeling | |
1Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, MO, United States, 2Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States, 3Radiology, Washington University in St. Louis, St. Louis, MO, United States |
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White matter in the brain is thought to be mechanically anisotropic and vulnerable to mechanical strain. By studying mechanical shear wave propagation in ex vivo brain tissue using magnetic resonance elastography (MRE), and comparing to results from computer models, shear moduli and shear anisotropy were estimated. This method allows the relaxation of assumptions of isotropy and homogeneity in traditional MRE inversions. The ratio of shear moduli governing shear parallel and perpendicular to fiber direction was approximately 1.25, indicating mild anisotropy in shear. This quantitative characterization of shear anisotropy in white matter has important implications for traumatic brain injury modeling. |
| 1373 | Utilization of MR Elastography for selective boost to dominant intraprostatic lesions | |
1Medical Physics Department, Saskatoon Cancer Centre, Saskatchewan Cancer Agency, Saskatoon, SK, Canada, 2Division of Biomedical Engineering, University of Saskatchewan, Saskatoon, SK, Canada, 3Department of Medical Imaging, University of Saskatchewan and Saskatoon Health Region, Saskatoon, SK, Canada, 4Department of Electrical & Computer Engineering, University of Saskatchewan, Saskatoon, SK, Canada |
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MRE has the ability to distinguish between elastic properties of the tissue. Furthermore, it is maturing as a technique to differentiate normal and cancerous tissue. In this work we present a strategy to establish |
| 1374 | Waveguide Effects in Cardiac Magnetic Resonance Elastography: A Finite Element Study | |
1Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States, 2Division of Engineering, Mayo Clinic, Rochester, MN, United States, 3Radiology, Mayo Clinic, Rochester, MN, United States |
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MR elastography is increasingly being applied to thin or small structures in which wave propagation is dominated by waveguide effects, which can bias stiffness results with common processing approaches. Finite element simulations of a realistic cardiac geometry were used to investigate the importance of waveguide effects, and to study the ability of the curl operator to remove these effects. The results establish that waveguide effects in a cardiac geometry can strongly bias stiffness results, but can be correctly handled by application of the curl operator to the measured displacement field, followed by true 3D inversion. |
| 1375 | In vivo cerebral MR elastography in a mouse model of Alzheimer’s disease: preliminary results | |
1Richard and Loan Hill Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States |
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In vivo magnetic resonance elastography (MRE) experiments on Alzheimer’s disease (AD) mouse model were conducted. The AD and Control mice were in the age group of 3-4 months (n = 4 for both). Median stiffness values for the overall mouse brain (central axial slices) and for the hippocampus region were calculated. No differences were observed between the two groups for the overall brain. For the hippocampus region, a trend of cerebral stiffness decrease in AD was measured. The small sample size did not allow for statistically significant conclusions. Further experiments are underway. |
| 1376 | Introduction of IVPD-MRE: Quantitative Assessment of Shear Stiffness without Spatial Derivative Operators | |
1Richard and Loan Hill Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States |
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Intravoxel phase dispersion (IVPD) in MRE describes signal loss of the MR magnitude due to spin dephasing imposed by voxel deformation. The extensity of IVPD is, among other parameters, dependent on the tissue stiffness. Therefore, tissue stiffness can be quantified by analyzing IVPD-imposed signal loss within a single voxel. The new approach does not rely on the use of spatial derivative operators as in conventional MR Elastography. In the present work, we examine in simulations the extensity of IVPD for varying experimental conditions and present stiffness maps of an inhomogeneous phantom, which were calculated by numerically fitting the IVPD equation. |
| 1377 | Comparison of mechanical properties of porcine brain tissue in vivo and ex vivo using MR elastography | |
1Mechanical Engineering, Washington University in St. Louis, St. Louis, MO, United States, 2Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States, 3Biomedical Engineering, University of Delaware, Newark, DE, United States |
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Computational models of traumatic brain injury (TBI) require accurate estimates of brain tissue mechanical properties, however properties of brain tissue ex vivo may differ from corresponding properties in vivo. To characterize possible differences, we performed MR elastography (MRE) on four Yucatan mini-pigs in vivo. Brain tissue samples from the same animals were later tested using ex vivo MRE. Shear moduli of both in vivo and ex vivo brain tissue were estimated using local direct inversion. Our results suggest that in vivo tissue is stiffer than ex vivo tissue at the same frequency, which has important implications for TBI model development. |
| 1378 | Hadamard Encoding for Magnetic Resonance Elastography | |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 3Department of Radiology, Academic Medical Center, Amsterdam, Netherlands |
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We propose the use of Hadamard encoding for Magnetic Resonance Elastography (MRE) of the full displacement vector field (4D-MRE). To this end, motion is encoded along the four diagonals of the regular cube spanned by the main gradient axes. This allows for a factor four higher phase accumulation compared to classical, unbalanced four-point encoding within the same acquisition time. In this abstract, we demonstrate the increase in phase-to-noise ratio for a gel phantom and show the direct benefit of using Hadamard encoding in-vivo to capture high-quality wave displacement maps in the brain. |
| 1379 | Development and validation of spin-echo planar imaging (SE-EPI) based MR Elastography on 3T: A phantom and volunteer study | |
1Philips, Cincinnati, OH, United States, 2Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 3Philips, Cleveland, OH, United States |
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While MRE based on 2D gradient recalled echo (GRE) MRI is FDA approved at 1.5T, the utility of 2D GRE MRE in the liver at 3T is limited by susceptibility effects and relatively long echo times that results in less SNR. MRE performance, particularly at 3T, can be improved by developing a faster technique that is less sensitive to liver T2* effects. In this work, we describe the development of SE-EPI MRE and its validation with respect to 2D GRE MRE in phantoms and healthy volunteers. |
| 1380 | Two novel low-cost 3D-printed mechanical actuators for MR elastography using exact end-to-end motion and centripetal force | |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany |
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For reliable quantification of the shear modulus of soft tissues, MR elastography (MRE) needs consistent methods of low-frequency wave induction to the region of interest in the human body. This work proposes two novel designs of 3D-printed mechanical actuators powered by compressed air. Driver A offers constant and specific actuation amplitude independent of the chosen frequency of wave induction. Driver B employs centripetal force for wave induction. Contrary to conventionally used air cushions, the amplitude increases at higher frequencies, thus, making it suitable for high frequency MRE and multi-source wave induction. |
| 1381 | Integration of MR Elastography and Fat/Water Separation Imaging | |
1Radiological Science, Tokyo Metropolitan University, Tokyo, Japan, 2National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan, 3Mechanical Engineering, TOKYO DENKI UNIVERSITY, Tokyo, Japan, 4Judo Neurophysiotherapy, University of Toyama, Toyama, Japan, 5System Emotional Science, University of Toyama, Toyama, Japan |
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In the present study, we developed a method to combine a simple MRE technique with a fat/water separation method (Dixon method) based on a conventional gradient-echo type multi-echo MR sequence (GRE-MultiEcho-MRE). Because the proposed method used the GRE-multiecho MRE, it is possible to select shortest in-/opposed-phase TE in the 1st TE. Thus, the proposed method allows to increase signal-to-noise ratio of fat/water images. |
| 1382 | Stacked Frequency Wave Inversion (SFWI): Heterogeneous And Edge-Preserving Direct Inversion For Magnetic Resonance Elastography (MRE) | |
1Radiological Science, Charité Universitätsmedizin Berlin, Berlin, Germany, 2Physics, Indian Institute of Technology Delhi, New Delhi, India, 3Medical Informatics, Charité Universitätsmedizin Berlin, Berlin, Germany |
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A new reconstruction method for MR elastography exploits a recent finding of mathematical uniqueness to develop a heterogeneity-accommodating and edge-preserving direct inversion method that uses first order derivatives. We investigate this new method on FEM models and a cohort of in vivo brain acquisitions by comparing it with a previously published method known as ESP. In models the method removes artefacts from use of second derivatives and homogeneity assumptions. In brain images appear better conditioned, but shows values differing from ESP in more anisotropic brain regionss. |
| 1383 | Validation of MRE measurements of shear modulus in both annulus fibrosus and nucleus pulposus within in two animal species | |
1Mechanical Engineering, Polytechnique Montreal, Montreal, QC, Canada, 2Research Center, Sainte-Justine Hospital, Montreal, QC, Canada, 3NeuRA, Sydney, Australia |
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Magnetic resonance elastography (MRE) is an effective method to measure the shear modulus of the nucleus pulposus, and its changes with degenerescence. However, MRE was not used for the annulus fibrosus. This study validated the use of MRE for the measurements of the shear modulus variations within the intervertebral discs between regions (annulus fibrosus versus nucleus pulposus) and animal species (bovine versus kangaroo). Shear dynamic mechanical tests and MRE showed equivalent tissue differences. This study also highlighted that the loading history of the intervertebral disc has to be considered when choosing an animal model. |
| 1384 | Magnetic Resonance Elastography based on Finite Deformation Imaging and Topology Optimization | |
1Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 2Dassault Systèmes, Germany, 3Mechanical Engineering, University of Colorado Boulder, CO, United States |
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We developed an inverse modeling approach for magnetic resonance elastography of tissues undergoing finite (large) deformations at physiologically-relevant loading rates. Inverse modeling was designed to directly incorporate displacement-encoded MRI with topology optimization to reveal stiffness distributions. The approach was validated using forward simulations with known material properties and boundary conditions, and sensitivity analyses. Inverse modeling may enable noninvasive characterization of material stiffness for complex tissues like articular cartilage in disease and repair. |
| 1385 | Optimal spatial resolution for accuracy and precision in simulated and experimental micro-MRE at 11.7 T | |
1Imagerie par Résonance Magnétique Médicale et Multi-Modalités, IR4M, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Orsay, France, 2Centre de Recherche sur l’Inflammation, CRI, Inserm, CNRS, Univ. Pierre et Marie Curie, Paris, France, 3Unité d’Imagerie par Résonance Magnétique et Spectroscopie, NeuroSpin, I2BM, DRF, CEA, Gif Sur Yvette, France, 4Imagerie Moléculaire In Vivo, IMIV, Inserm, CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Orsay, France |
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MRE outcomes depend on various factors, which include SNR, spatial resolution, mechanical frequency, induced shear wave amplitude, and reconstruction method. It was formerly shown in a simulation study that 7 to 10 voxels were needed to properly resolve the shear wavelength, λref, and both accurately and precisely quantify the mechanical properties of the targeted tissue by inversion of the equation of motion. The purpose here is to experimentally reproduce the conditions defined by the simulation to determine the actual influence of the acquisition voxel size, a, on MRE acquisitions and validate the predicted λref/a conditions for optimal MRE reconstruction. |
| 1386 | Alteration of mechanical tissue parameters during progressive formalin fixation measured by broadband Magnetic Resonance Elastography using a compact and portable tabletop scanner | |
1Department of Medical Informatics, Charité - Universitätsmedizin Berlin, Berlin, Germany, 2Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany, 3Beuth Hochschule für Technik Berlin, Berlin, Germany, 4Pure Devices GmbH, Würzburg, Germany |
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A compact tabletop MR elastography (MRE) device was employed for rheological tests of soft tissue samples to measure the change of viscoelastic powerlaw constants in liver and brain tissue during progressive fixation. Shear-modulus dispersion functions were acquired from 300 to 5700Hz in animal tissues at different states of formaldehyde fixation and fitted by the rheological springpot-powerlaw model. Formalin fixation reduced viscosity and increased elasticity of liver tissue faster and to a higher degree than in brain tissue similar to the alteration of mechanical properties observed by in vivo elastography of hepatic fibrogenesis. |
| Exhibition Hall | Monday 8:15 - 10:15 |
| 1387 | Robust k-space trajectory mapping with data readout concatenation and automated phase unwrapping reference point identification | |
1Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 2Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, 3Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 4Neuroimaging Research, Barrow Neurological Institute, Phoenix, AZ, United States |
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A fundamental challenge when mapping k-space trajectories that require unwrapping of phase proportional to position in k-space is the accrual of phase during gradient prewinders and phase encodes, which are not sampled. To overcome this challenge, we present a simple method using data readout concatenation and automated phase unwrapping reference point identification to robustly map a broad range of trajectories. This approach works for any k-space trajectory for which data readouts can be connected to provide a path crossing near the center of k-space from which 1D phase unwrapping can be performed. |
| 1388 | Characterization of k-space trajectory error using time delay correction for EPI | |
1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, 2Medical Physics, Department of Radiology, University Medical Center Freiburg, Freiburg, Germany, 3Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland |
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The ghosting artifacts in echo-planar imaging can be greatly reduced by aligning the k-space coordinates between odd and even lines based on their relative time delay. However, we found this approach is limited in artifact reduction. Specifically, we found that the image still has prominent artifacts and high spatial frequency k-space coordinates for even and odd lines still differ from each other significantly after time delay correction. This result suggested the origin of the ghosting artifact is beyond the time delays between neighboring readouts. The image artifact, however, can be greatly reduced using trajectory correction. |
| 1389 | Susceptibility-induced local ΔB0 variations are essential for predicting EPI distortions in the breast | |
1Center for Image Sciences, UMC Utrecht, Utrecht, Netherlands, 2Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands |
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Applications involving EPI readouts, such as diffusion weighted imaging and functional imaging, are hampered by geometrical distortions caused by static field inhomogeneities (ΔB0). Pixel shift maps can be inferred from ΔB0 maps. Though it is common practice to smooth these maps before calculating pixel shifts, doing so reduces susceptibility-induced local ΔB0 variations. This study investigates the importance of local ΔB0 changes in correctly predicting EPI distortions. Preliminary data obtained from the human breast in-vivo shows that susceptibility-induced changes in ΔB0 are essential in accurately predicting EPI distortions. |
| 1390 | Performance assessment of EPI-distortion correction of brain images; which plane and phase encoding direction should be chosen? | |
1Radiology, Harvard Medical School, Boston, MA, United States |
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Echo-Planar-Imaging (EPI) is often used in DW-MRI to acquire a full volume in a short period of time. These images, however, show substantial local geometric and intensity distortions due to the susceptibility artefact. A popular method to correct for these distortions is to acquire a pair of images with opposite phase-encoding-directions (PED) but same slice-encoding-direction (SED) from which the distortion field can be estimated. While the choice of SED and PED likely impacts the correction effectiveness, it has never been rigorously quantitatively evaluated. In this work, we acquired scans with all combinations of SEDs and PEDs and evaluated the correction quality of three different distortion correction implementations. |
| 1391 | Characterising and correcting for MR signal drift in dynamic SPGR oxygen-enhanced MRI acquisitions | |
1Division of Informatics, Imaging and Data Sciences, The University of Manchester, Manchester, United Kingdom, 2CRUK & EPSRC Cancer Imaging Centre in Cambridge and Manchester, Cambridge and Manchester, United Kingdom, 3Division of Molecular and Clinical Cancer Studies, The University of Manchester, Manchester, United Kingdom, 4Department of Radiology, The Christie NHS Foundation Trust, Manchester, United Kingdom, 5Bioxydyn Ltd., Manchester, United Kingdom |
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Dynamic oxygen-enhanced (OE)-MRI, in combination with dynamic contrast-enhanced (DCE)-MRI, shows use in identifying hypoxic regions in tumours, but relies on an accurate knowledge of baseline (pre contrast-agent administration) tissue characteristics. We present a method of characterising baseline signal drift in an oxygen-enhanced MRI study of preclinical tumour xenografts, where the drift would otherwise impede quantitative analyses. We then demonstrate the utility and necessity of our methods through a comparison of calculated ∆R1 values (reflecting tissue oxygen delivery) with and without our baseline drift correction. |
| 1392 | Comprehensive analysis of MR geometric distortion of multiple pulses sequence for radiotherapy applications | |
1Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong, Hong Kong |
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This study evaluated three-dimensional geometric distortion of six selected potential MR sequences for radiotherapy applications, acquired from a 1.5T 700mm-wide bore MR-simulator. Every sequence was investigated in three acquisition-orientations and multiple receiver-bandwidths, under various diameter-sphere-volume (DSVs). A large geometric accuracy phantom was constructed to quantify the distortion within the largest field-of-view allowed. Detailed distortion statistics, evaluation based on distortion requirements of different radiotherapy applications and comparison among sequences were reported. Results showed that sequence-types and acquisition-orientations were more influential to distortion than receiver-bandwidths. The distortion statistics are also a valuable guideline for sequence selection and optimization for radiotherapy. |
| 1393 | Longitudinal Monitoring of MR Image Distortion of a dedicated MR-Simulator for Radiotherapy over a 6-month Period | |
1Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, Hong Kong, Hong Kong |
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This study investigated the variation of |
| 1394 | Robust On- and Off-Resonance constant amplitude spin-lock at the presence of B1 RF and B0 field inhomogeneity | |
1Imaging and Interventional Radiology, The Chinese University of Hong Kong, New Territory, Hong Kong |
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T1rho is often measured by constant amplitude spin-lock, which can be played out either on-resonance or off-resonance. A major challenge to T1rho imaging with constant amplitude spin-lock is its susceptibility to B1 RF and B0 field inhomogeneity. A method to improve the robustness of on- and off-resonance constant amplitude spin-lock is presented in this work. The experimental results indicated that the proposed method can achieve superior image quality and improved quantification accuracy compared to the conventional approach in the presence of system imperfections. |
| 1395 | Correct Shaking Artifact in Diffusion Spectrum Imaging Using Estimated Maximum Likelihood | |
1Graduate Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan, 2Institute of Medical Device and Image, National Taiwan University College of Medicine, Taipei, Taiwan, 3Molecular Imaging Center, National Taiwan University College of Medicine, Taipei, Taiwan |
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Unexpected phase errors occurred in the k-space of the diffusion spectrum EPI sequence would lead to abrupt shifts in the phase-encoding direction across different diffusion gradient directions which cause shaking artifact of the image. The shaking artifact can lead to errors in image registration and diffusion index calculation. Here, we developed an estimated maximum likelihood method to detect and correct image shifts. After correcting the shaking artifact, the performance of registration and the diffusion index calculation were significantly improved comparing to the images without correction. |
| 1396 | Improving Apparent Diffusion Coefficient Accuracy on a Compact 3T MRI Scanner using Gradient Non-linearity Correction | |
1Radiology, Mayo Clinic, Rochester, MN, United States, 2GE Global Research, Niskayuna, NY, United States |
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Errors are introduced into apparent diffusion coefficient quantification of diffusion weighted imaging (DWI) due to imperfect gradient linearity. A post-processing gradient non-linearity (GNL) correction algorithm can alleviate this problem on a conventional whole-body MR scanner equipped with a symmetrical gradient system. A compact 3T (C3T) scanner with a high-performance gradient was recently developed and exhibits more complex GNL than conventional whole-body gradients due to its asymmetric design. Here, we test the robustness of this GNL correction on the C3T using phantom and in-vivo experiments, and demonstrated improved accuracy of quantitative maps for DWI on the C3T using this algorithm. |
| 1397 | Compensation for Distribution of Receiving Sensitivity in Body Coil | |
1Healthcare Business Unit, Hitachi, Ltd., Tokyo, Japan |
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We propose a new method to compensate for distribution of receiving sensitivity in a body coil. It corrects a shading artifact that remains after compensation based on sensitivity ratio of surface and body coils. The method utilizes body coil sensitivity taken in advance with an uniform phantom. The body coil sensitivity is transformed by referring the ratio of intensity between channels. The method is intrinsically insensitive to tissue contrast because it is cancelled by taking ratio. The method is useful when the reference image has strong tissue contrast. The effect of proposed method is examined by phantom and volunteer study. |
| 1398 | Shimming for BOLD sensitivity in the brain | |
1Oxford Centre for Functional MRI of the Brain, University of Oxford, Oxford, United Kingdom |
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Whole brain resting state fMRI benefits greatly from shimming due to increases in BOLD sensitivity. This work presents a rapid shim calculation method using prior knowledge of nonlinear optimization results on a large database of field maps, which can significantly reduce the time spent on shim determination for BOLD sensitivity optimization, whilst delivering shim quality that is closer to the results of nonlinear optimization. |
| 1399 | Single-Scan GRE Myelin Water Imaging with Macroscopic Field Inhomogeneity Compensation | |
1Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of, 2Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea, Republic of |
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In this study, we propose a single-scan GRE-MWI method that corrects for the effects of macroscopic field inhomogeneity using a modified z-shimming. In addition, a new three-component magnitude model corresponding to the modified sequence is proposed. Compared to the conventional method, the results showed an improved MWF estimation, particularly in frontal lobe regions. |
| 1400 | Partial Volume Correction and Transit Time correction effect in absolute perfusion quantification with 3D Pseudo-Continuous Arterial Spin Labelling. | |
1Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, Netherlands, 2Rey Juan Carlos University, 3A Coruña University, 4GE Healthcare |
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This work studies partial volume correction and transit time correction in CBF assessment with 3DPCASL sequence. It is shown how important are these corrections depending on brain regions and the amount of gray matter inside the voxel. |
| 1401 | Validation of an ASL processing pipeline accounting for low SNR and the presence of an EPI artifact, using simulated and real data. | |
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom, 2Neuroimaging in Cardiovascular Disease (NICAD) Network, University of Sheffield, Sheffield, United Kingdom, 3Department of Psychology, University of Sheffield, Sheffield, United Kingdom, 4Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital, Hvidovre, Denmark, 5Center for Magnetic Resonance, DTU Elektro, Technical University of Denmark, Lyngby, Denmark |
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This study aimed to optimize a processing pipeline for QUASAR ASL. We have focused on 3 aspects: the assignment of AIFs in voxels; dealing with voxels having excessive values potentially due to an EPI artifact; and minimization of partial volume effects. Simulations showed that GM CBF values closer to the ground truth are obtained by using AIFs in a distance double than the nearest-neighbor AIF to every voxel. In terms of an EPI artifact present in the analysis, we have shown that identification and exclusion of influenced voxels with a developed algorithm, results in values closer to the expected ones. |
| 1402 | Patch-based super-resolution for arterial spin labeling MRI | |
1Siemens Healthineers, Saint-Denis, France, 2Univ Rennes 1, F - 35043, Rennes, France, 3INRIA, F - 35042, Rennes, France, 4INSERM, U746, F - 35042, Rennes, France, 5CNRS, U 6074, F - 35042, Rennes, France, 6CHU Rennes, F - 35033, Rennes, France |
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Partial volume effects (PVE) are an important limitation of arterial spin labeling (ASL) acquisitions, impacting the validity of quantitative cerebral blood flow (CBF) estimations. This abstract presents a super-resolution algorithm, which includes information of high resolution (HR) structural images to reconstruct HR CBF maps from low resolution ASL series, without increasing the acquisition time. Compared with nearest neighbor, trilinear and 3rd order spline interpolations, the proposed algorithm is found to generate a CBF image closer to the one obtained with a reference HR ASL acquisition. CBF calculations can therefore be improved by using this algorithm, which reduces the PVE. |
| 1403 | Automated segmentation of Intramuscular Connective Tissue (IMCT) from skeletal muscle in presence of artifacts: Application to Changes in IMCT in an Unilateral Limb Suspension Induced Acute Atrophy Model in the Plantarflexors | |
1Physics, San Diego State University, San Diego, CA, United States, 2Physics, UC San Diego, San Diego, CA, United States, 3Radiology, UC San Diego, San Diego, CA, United States |
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Chronic muscle atrophy can be induced by limb suspension and is characterized by a loss of muscle mass and force. However, there could also be changes to the connective tissue volume that may contribute to the loss of muscle function. We studied the changes in connective tissue volume in a model of chronic atrophy induced by Unilateral limb suspension (ULLS) using ultralow TE sequences. We integrated an artifact correction algorithm to a 3D fuzzy segmentation algorithm to automatically segment the connective tissue from dual echo UTEs images corrupted by artifacts. Percent connective tissue increased post-ULLS but not the absolute values. |
| 1404 | Contrast and Resolution Mixing for Magnetic Resonance Fingerprinting | |
1Application Development, Siemens Healthcare, Erlangen, Germany, 2Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany, 3Department of Biomedical Engineering, Case Western Reserve University, OH, United States, 4Dept. of Radiology, Case Western Reserve University and University Hospitals of Cleveland, OH, United States |
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Quantitative parameter maps obtained from Magnetic Resonance Fingerprinting (MRF) are sensitive to B1+ inhomogeneities. Extending a dictionary by an additional B1+ dimension is a promising approach to account for this. In order to improve the differentiation of data in the B1+ dimension, we implemented a novel B1+ sensitive encoding. This approach employs the extension of the conventional FISP encoding by RF spoiled parts. Since high undersampling factors prevent a direct implementation of this technique, the undersampling pattern is varied during the acquisition. We use a spiral acquisition scheme which samples most of the FISP encoded parts of the fingerprint with high resolution. RF spoiled parts as well as a small fraction of the FISP encoded parts are being sampled with low resolution. |
| 1405 | Background Field Removal Technique using Non-regularized Variable Kernels Sophisticated Harmonic Artifact Reduction for Phase Data for Quantitative Susceptibility Mapping | |
1Department of Radiology, Nagoya City University Hospital, Nagoya, Japan, 2Unit of Healthcare Business, Hitachi, Ltd. |
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QSM is relatively new biochemical and quantitative reconstruction method which directly estimates the iron distribution. It needs a precision of separation of local field from background field for measurement of accurate susceptibility value. We introduced a novel method using non-regularized variable kernels sophisticated harmonic artifact reduction for phase data (NR-VSHARP). The proposed method utilized multiple kernel sizes and minimization of norm only inside mask without any regularization parameter. NR-VSHARP enabled to estimate high accurate local field, compared with VSHARP. NR-VSHARP method provides high accurate local field map with saving cortical information. |
| 1406 | Noise and Artifact Reduction in 3D Abdominal and Thoracic Imaging using CAIPIRINHA | |
1Radiology, University of Wisconsin, Madison, WI, United States, 2Medical Physics, University of Wisconsin, Madison, WI, United States, 3Biomedical Engineering, University of Wisconsin, Madison, WI, United States, 4Medicine, University of Wisconsin, Madison, United States, 5Emergency Medicine, University of Wisconsin, Madison, WI, United States |
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This study investigated Controlled Aliasing In Parallel Imaging Results IN Higher Acceleration (CAIPIRINHA) in combination with Rotated Slab Excitation (ROSE) to reduce parallel imaging artifacts and residual aliasing artifacts using a coronal reconstruction and sagittal excitation. Images acquired using the CAIPIRINHA sampling pattern had fewer parallel imaging artifacts than using a conventional sampling pattern. G-factor analysis also demonstrated improved SNR performance using the CAIPIRINHA sampling pattern. The CAIPIRIHNA sampling pattern when combined with ROSE reduced residual aliasing artifacts and parallel imaging artifacts. This enables higher acceleration factors for shorter scan times, without sacrificing image quality. |
| Exhibition Hall | Monday 8:15 - 10:15 |
| 1407 | Continuous domain compressed sensing (CD-CS): application to accelerated dynamic MRI | |
1Electrical and Computer Engineering, University of Iowa, Iowa City, IA, United States, 2EECS, University of Michigan, MI, United States |
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We introduce a novel continuous domain compressed sensing (CD-CS) framework for the recovery of MRI data. We formulate the recovery of the high-resolution continuous domain Fourier coefficients of the image from few of its samples as a structured low-rank matrix completion problem. We also introduce novel algorithms to solve this matrix completion problem in run-times that are comparable with discrete CS formulations. The application of this algorithm to (2D+time) dynamic MRI problems is observed to yield significantly improved reconstructions compared to state of the art CS methods. |
| 1408 | Novel annihilation filter framework for accelerated parameter mapping | |
1Electrical and Computer Engineering, University of Iowa, Iowa City, IA, United States |
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Quantitative parameter maps offer valuable information about various tissue attributes, which are early markers for many neurological disorders. However the long acquisition time of the associated image time series puts a restriction on the achievable spatial resolution. In this work, we introduce a novel framework, which exploits the exponential nature of the time profiles at every pixel and spatial smoothness of the exponential parameters to recover the images from highly under-sampled measurements. Our preliminary results clearly demonstrate the potential of the proposed algorithm. |
| 1409 | Task-based Optimization of Regularization in Highly Accelerated Speech RT-MRI | |
1Electrical Engineering, University of Southern California, Los Angeles, CA, United States |
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Speech RT-MRI has recently experienced significant improvements in |
| 1410 | Study on regularization paremeter tuning in compressed sensing using no-reference image quality assessment | |
1School of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea, Republic of |
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In Magnetic Resonance Imaging system, acquiring fewer measurements is required to reduce scan time, but it leads the aliasing artifact. Compressed Sensing is exploited to reconstruct image from undersampled data without artifacts by solving the optimization problem. However, It has some difficulites in selecting regularization parameters and this abstract propose the way to select regularization parameters by evaluating image quality. The quality of reconstructed image from proposed method is much better than the image from manual parameters. This study also has potential to be helpful in fast MR imaging. |
| 1411 | Compressed Sensing MRI Using Bunched Phase Encoding | |
1School of Software and Electrical Eng, Swinburne University of Technology, Melbourne, Australia, 2Dept of Electrical and Computer Systems Eng, Monash University, Melbourne, Australia |
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This abstract presents a novel method for compressed sensing (CS) MRI. This method combines the variable density random undersampling and iterative image reconstruction in CS-MRI with the regularly reduced bunched phase encoding (BPE) and linear equation based image reconstruction of BPE-MRI to further reduce data acquisition time and improve image quality of CS-MRI. Simulation results demonstrate the effectiveness and advantage of the presented method. |
| 1412 | A Novel Hybrid Total Variation Minimization Method to MRI Reconstruction from Highly Undersampled Data | |
1Department of Biomedical Engineering, Department of Electrical Engineering, The State University of New York at Buffalo, Buffalo, NY, United States, 2School of Electronic Engineering, Xidian University, Xi'an, People's Republic of China, 3Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Shenzhen, People's Republic of China |
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This abstract presents a novel hybrid total variation minimization algorithm to reconstruct MR images from reduced measurements. The method combines the benefits of both L1 and homotopic L0 minimization algorithms for sparse signal reconstruction in the sense that substantially fewer measurements are needed for exact reconstruction. The algorithm minimizes the conventional total variation when the gradient is small, and minimizes the L0 of gradient when the gradient is large. An auto-adaptive threshold determines the transition between L1 and L0 of the gradients. The experimental results show the proposed algorithm outperforms either L1 or homotopic L0 minimization when the same reduction factor is used. |
| 1413 | High resolution 3D MRI reconstruction using 3DMDTV regularization | |
1Harbin Institute of Technology, Harbin, People's Republic of China, 2CSIC 703 Institute, 3University of Iowa, Iowa City, IA, United States |
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Three-dimensional (3D) MRI plays an important role in many clinical applications due to its ability to provide the full geometry of the targeted region of the body. However, speed limitation remains the key challenge to 3D MRI. Here, we present a compressed sensing reconstruction scheme using the 3DMDTV regularization. The experiments demonstrate that for high acceleration factors, the proposed method has better performance than other schemes by providing more accurately recovered images with more subtle details preserved. |
| 1414 | Accelerated 3D Arterial Spin Labeling using Cartesian Acquisition with Spiral Reordering and Compressed Sensing | |
1Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 2Bioengineering, UT Dallas, Dallas, TX, United States, 3Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States |
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Arterial spin labeling (ASL) is a non-contrast perfusion imaging method for MRI. However, 2D ASL suffers from low signal to noise ratio. 3D ASL is favorable to overcome the limitation of 2D ASL, but 3D acquisition is time-consuming, so acceleration of 3D ASL is highly desired. The new compressed sensing (CS) theory allows perfect reconstruction far below Nyquist rate. We implemented a novel 3D TSE acquisition using Cartesian Acquisition with SPiral Reordering (CASPR), which can be undersampled and combined with CS. Preliminary results show improved image quality using 3D Sparse-BLIP reconstruction that is comparable to fully sampled acquisition. |
| 1415 | Accelerated MR Diffusion Tensor Imaging Using Partial Fourier Compressed Sensing | |
1ECE, University of Maryland College Park, College Park, MD, United States, 2Neurophysiology Imaging Facility, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, and National Eye Institute, National Institutes of Health, Bethesda, MD, United States, 3NINDS/LFMI/CMS, National Institutes of Health, Bethesda, MD, United States, 4Diagnostic Radiology and Nuclear Medicine, UM School of Medicine, Baltimore, MD, United States |
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3D-DTI are often used in ex vivo imaging to achieve superior spatial resolution and to map fine white matter structure. However, image acquisition time is long especially when many diffusion directions are used to better define orientation profiles and resolve crossing fibers. In this study we apply a new imaging acceleration technique – Partial Fourier Compressed Sensing (PFCS) on DTI acceleration. We demonstrated PFCS provide satisfactory reconstruction with only half of the raw data while retaining fine anatomical details on DTI parameter maps. |
| 1416 | Beyond Low-Rank and Sparsity: A Manifold driven Framework for Highly Accelerated Dynamic Magnetic Resonance Imaging | |
1Electrical Engineering, University at Buffalo, State University of New York, Buffalo, NY, United States, 2Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, United States |
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The state-of-the-art methods in accelerating dynamic Magnetic Resonance (dMR) Imaging rely on sparse and/or low-rank priors. We propose a novel manifold driven framework that exploits the manifold smoothness priors to highly accelerate data acquisition in dMR. We postulate that images in dMR lie on or close to a smooth manifold and learn the manifold geometry from the navigator signals. Capitalizing on the learned manifold, we develop two regularization loss functions and subsequently build a framework to reconstruct dMR images from highly undersampled k-space data. The proposed method is shown to be superior than competitive methods in different data sets. |
| 1417 | Application of Iterative Reconstruction for MR Digital Subtraction Angiography: Toward Better Visualization of Small Vessels and Reduction of Gadolinium-Based Contrast Media. | |
1Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan, 2Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan, 3Siemens Healthcare GmbH, Erlangen, Germany |
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Improved signal and temporal footprint for dynamic MRA due to the retrospective iterative reconstruction may better visualize small peripheral vessels with reduced GBCA dose. CE-MRA-TWIST images were reconstructed twice from the same raw data, with the standard product reconstruction and with iterative reconstruction (IT) by using L1 wavelet regularization in space and time. CE-MRA-IT-TWIST nicely visualized hemodynamics in the brain even with 20% GBCA dose administration compared with CE-MRA-TWIST, especially in the arterial phase. Enhancement slope of CE-MRA-IT-TWIST was statistically higher than that of CE-MRA-TWIST. |
| 1418 | A low rank Hankel matrix reconstruction approach to recover hybrid time and frequency data in non-uniformly sampled magnetic resonance spectroscopy | |
1Department of Electronic Science, Xiamen University, Xiamen, People's Republic of China, 2School of Computer and Information Engineering, Xiamen University of Technology, Xiamen, People's Republic of China |
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Magnetic resonance spectroscopy has many important applications in bio-engineering while the acquisition of high dimensional spectroscopy is usually time consuming. Non-uniformly sampling can speed up the data acquisition but the missing data points have to be restored with proper signal models. In this work, a specific two dimensional magnetic resonance signal, of which the first dimension lies in time domain while the second dimension lies in frequency domain, is reconstructed with a proposed low rank enhanced Hankel matrix method. Results on realistic magnetic resonance spectroscopy shows that proposed method outperform the state-of-art compressed sensing method on recovering low intensities spectral peaks. |
| 1419 | Accelerating 3D Head-and-Neck MR Imaging Using Compressed Sensing with Structure-Guided Total Variation for MR-Guided Multi-Fractional Radiotherapy | |
1Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong, 2Department of Radiotherapy, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong |
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MR image-guided radiotherapy (IGRT) holds potentials on outcome improvement in the head-and-neck (HN) radiotherapy. Patients receiving MR-guided multi-fractional HN IGRT are immobilized in each treatment fraction and set up to the exact position as of the treatment planning scan. Inter-fractional MR images are supposed to show highly correlated anatomy structure and edge information which can be incorporated into compressed sensing (CS) based MR reconstruction to shorten the scan time while preserve image quality in multiple fractions. In this study, we investigated the feasibility of accelerating high spatial resolution 3D MRI using CS with structure-guided total variation for multi-fractional HN radiotherapy. |
| 1420 | Accelerate multi-dimensional magnetic resonance spectroscopy with low rank tensor and Hankel structures | |
1Department of Electronic Science, Xiamen University, Xiamen, People's Republic of China, 2School of Life Sciences, University of Science and Technology of China, Hefei, People's Republic of China, 3Department of Mathematics, Hong Kong University of Science and Technology, People's Republic of China, 4School of Computer and Information Engineering, Xiamen University of Technology, Xiamen, People's Republic of China |
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Non-uniformly sampling is an effective way to accelerate high-dimensional magnetic resonance spectroscopy (MRS). The spectrum is usually reconstructed with proper prior knowledge. In this work, we exploit the intrinsic N-D exponential signals of multi-dimensional MRS to reconstruct the spectrum. A low rank tensor representation of multi-dimensional MRS and the exponential structure of the associated factors are simultaneously explored. Results on 3-D MRS data shows that the proposed method can faithfully reconstruct the spectrum from a small amount of measurements, allowing a significant reduction of acquiring time in real applications. |
| 1421 | A novel compressed sensing inspired approach for flow reconstruction | |
1Department of Electrical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, 2Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Santiago, Chile, 3Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile, 4Department of Radiology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile |
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High scan times are one of the most important drawbacks in 4D flow scans and multiple solutions have been proposed to solve this issue. We propose a novel method for undersampled flow reconstruction inspired on the ideas of compressed sensing. By considering the magnitude and complex phase as separate variables, we were able to impose independent properties on each, such as having a constant magnitude over all flow enconding acquisitions and enforcing low phase values on low magnitude areas, thus directly reducing the resulting images' noise. Our method was able to successfully reconstruct flow data with negligible error from undersampled data. |
| 1422 | Quantitative Susceptibility Map Reconstruction from MR Phase Data Using Morphology-Adaptive Total Variation | |
1Guangdong Provincial Key Laborary of Medical Image Processing, School of Biomedical Engineering, Southern Medical University, Guangzhou, People's Republic of China, 2Philips Healthcare, Guangzhou, People's Republic of China |
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MEDI reduces streaking artifacts in QSMs by minimizing total variation in smooth regions in the susceptibility map. However, MEDI still contains artifacts near image edges because this method does not impose any constraint on voxels near edges. We aim to improve the reconstruction of quantitative susceptibility map from MR phase data by introducing morphology-adaptive TV regularization which imposes the TV constraint on the whole susceptibility map but with different weights in smooth and non-smooth regions. The performance of the proposed method is demonstrated in both simulation and in vivo data sets. |
| 1423 | Multi-contrast image guided graph representation and its application in compressed sensing MRI reconstruction | |
1Dept. of Communication Engineering, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen 361005, China, xiamen, People's Republic of China, 2Dept. of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen 361005, China, People's Republic of China, 3Dept. of Computer Science, Xiamen University of Technology, Xiamen 361024, China, People's Republic of China |
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Under-sampling the k-space data and reconstructing images with sparsity constraint is one efficient way to accelerate magnetic resonance imaging However, achieving high acceleration factor is challenging since image structures may be lost or blurred when the sampled information is not sufficient. In this work, we propose a new approach to reconstruct magnetic resonance images by learning the prior knowledge from multi-contrast images with graph-based sparsifying transform. To incorporate extra information from multi-contrast image, registration is included in a bi-level optimization frame as well as the sparse reconstruction. Experiment results demonstrate that the proposed method outperforms the state-of-art with high accelerating factor. |
| 1424 | Image quality impact of randomized sampling trajectories: implications for compressed sensing | |
1Biomedical Engineering, University of Calgary, Calgary, AB, Canada, 2Seaman Family MR Centre, Foothills Medical Centre, Calgary, AB, Canada, 3Radiology, University of Calgary, Calgary, AB, Canada, 4GE Healthcare, Calgary, AB, Canada |
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Compressed sensing (CS) has the potential to drastically reduce MR acquisition times, |
| 1425 | Optimization of Reconstruction Parameters of Compressed Sensing STIR SEMAC for Metal Artifact Reduction MRI of Hip, Knee and Ankle Arthroplasty Implants: How many Iterations and how much Regularization is needed? | |
1Johns Hopkins University, Baltimore, MD, United States, 2Siemens Healthcare GmbH, 3Siemens Healthcare USA |
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Compressed sensing-(CS)-based Slice Encoding for Metal Artifact Correction (SEMAC) turbo spin echo (TSE) pulse sequences achieve high–quality metal artifact reduction MRI around arthroplasty implants. Compressed sensing-based undersampling of k-space permits the time-neutral use of SEMAC, but requires iterative reconstruction algorithms, which are time consuming. We determined minimum number of iterations and regularization required for diagnostic image quality of STIR CS-SEMAC data sets of hip, knee and ankle arthroplasty implants. Our results show that 15-17 iterations and 0.0035 regularization results in optimal image quality of STIR CS-SEMAC images, which currently requires 4-5 minutes of reconstruction time. |
| 1426 | Flexible Prospective Compressed Sensing Acceleration of Prostate DCE-MRI with Quantized CIRCUS | |
1Biomedical Translational Imaging Centre (BIOTIC), Nova Scotia Health Authority, Halifax, NS, Canada, 2Diagnostic Radiology, Dalhousie University, Halifax, NS, Canada, 3Physics and Atmospheric Science, Dalhousie University, Halifax, NS, Canada, 4Biomedical Engineering, Dalhousie University, Halifax, NS, Canada |
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Improving the temporal resolution of dynamic contrast-enhanced (DCE) MRI sequences often requires a reduction in image spatial resolution or quality. We propose an acquisition and reconstruction strategy, Quantized CIRCUS, which allows reconstruction of prospectively accelerated DCE-MRI data with desired spatial and temporal resolution, similar to golden-angle radial acquisition schemes but using Cartesian sampling. We demonstrate that this approach allows improved temporal resolution compared to standard clinical methods, without significant degradation of image quality or resolution, which may provide more accurate information for diagnosis of diseases like prostate cancer. |
| 1427 | Flexible convex optimization with non-smooth regularizations for accelerated MRI reconstructions | |
1United-Imaging Healthcare America, Houston, TX, United States, 2Indiana University School of Medicine, Fort Wayne, IN, United States |
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Convex optimization with non-smooth regularizers has recently gained increased interest as it has shown excellent performance and the ability to facilitate most of reconstruction problems in MR convincible. While there are many approaches towards its fulfillment, a flexible yet easy and comprehensive to realize method is always beneficial. One of the algorithms is proposed in this abstract. and we demonstrate that this algorithm can be easily adapted to many reconstruction problems in MRI with accelerated performance. |
| 1428 | Quantitative Evaluation of Temporal Sparse Regularizers for Compressed Sensing Breast DCE-MRI | |
1School of Science, Nanjing University of Science and Technology, Nanjing, Jiangsu, People's Republic of China, 2Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN 37232, 3Institute for Computational and Engineering Sciences, and the Departments of Biomedical Engineering and Internal Medicine, The University of Texas at Austin, Austin, Texas, USA |
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We quantitatively evaluate temporal sparse regularizers for breast DCE-MRI data under standard compressed sensing schemes. We consider five temporal regularizers on 4.5x retrospectively undersampled Cartesian in vivo breast DCE-MRI data, namely Fourier transform (FT), Haar wavelet transform (WT), total variation (TV), second order total generalized variation (TGV$$$_{\alpha}^{2}$$$) and nuclear norm (NN). Both signal-to-error ratio and concordance correlation coefficients of the derived pharmacokinetic parameters $$$K^{\text{trans}}$$$ (volume transfer constant) and $$$v_\mathrm{e}$$$ (extravascular extracellular volume fraction) are estimated. Results show that NN produces the lowest image error while TV/TGV$$$_{\alpha}^{2}$$$ produce the most accurate pharmacokinetic parameters. |
| 1429 | Assessing a radial multi-spin-echo sequence for robustness to motion artefacts in quantitative NMR imaging | |
1NMR Laboratory, Institute of Myology, Paris, France, 2CEA, DRF, I²BM, MIRCen, Paris, France, 3Consultants for Research in Imaging and Spectroscopy, Tournai, Belgium |
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Fast parametric NMR imaging such as T2 and fat fraction mapping can be performed with a multi-spin-echo (MSE) sequence and an EPG-based model. Here, we compared a radial MSE encoding scheme to a standard Cartesian acquisition to monitor these two parameters in area subject to respiratory motion artifacts. Results show that the radial sequence was less affected from motion than the cartesian one and then improved the confidence of parameters estimation at these locations. |
| Exhibition Hall | Monday 8:15 - 10:15 |
| 1430 | Evaluating effect of B1 field Inhomogeneity on DCE-MRI Data Analysis of Brain Tumor Patients at 3T | |
1Centre for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi, India, 2Department of Radiology, Fortis Memorial Research Institute, GURGAON, 3Biomedical Engineering, All India Institute Of Medical Science, New Delhi, India |
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In the current study, transmit B1 field inhomogeneity(B1FI) distribution and propagation of flip-angle(FA) related errors to Dynamic-contrast-enhanced(DCE) MRI data analysis in brain tumors of human subjects at 3T MRI were studied. Experimental and simulation studies were performed to evaluate the propagation of these errors to DCE-MRI data analysis and its correction were performed during signal intensity(S(t)) to concentration-time-curve(C(t)) conversion. This study show that B1FI introduced substantial errors in DCE-MRI data analysis(tracer-kinetic and hemodynamic parameters) and these errors were mitigated by correcting FA using B1 map. B1FI related error also showed dependence on concentration of contrast agent and length of concentration-time-curve. |
| 1431 | Brain Network Atlas Estimation using Centered Graph Shrinkage with Application to Developing and Aging Brains | |
1Department of Radiology and BRIC, University of North Carolina, Chapel Hill, NC, United States, 2Department of Brain and Cognitive Engineering, Korea University, Seoul, Republic of Korea |
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Learning how to average brain networks (i.e., build a brain network atlas) constitutes a key step in creating a reliable ‘mean’ representation of a set of normal brains, which can be used to spot deviations from the normal network atlas (i.e., abnormal cases). However, this topic remains largely unexplored in neuroimaging field. In this work, we propose a network atlas estimation framework through a non-linear diffusion along the local neighbors of each node (network) in a graph. Our evaluation on both developing and aging datasets showed a better ‘centeredness’ of our atlas in comparison with the state-of-the-art network fusion method. |
| 1432 | Robust and fast phase unwrapping strategy to improve SWI quality | |
1United Imaging of Healthcare America, Houston, TX, United States, 2Shanghai United Imaging of Healthcare, Shanghai, People's Republic of China |
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A robust and fast phase unwrapping strategy was developed for multi-echo SWI, to improve image quality where classic SWI fails, such as cavity vicinity regions, as well as to provide pristine field map for subsequent QSM applications. A smoothing and a seed prioritizing method were proposed, which was demonstrated to provide very robust unwrapping on phase difference map between neighboring echoes. And with a high quality unwrapped phase difference map, the phase of all echoes can be robustly unwrapped in seconds. |
| 1433 | A Fast Adaptive Multispectral Nonlocal Denoising Filter | |
1Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, United States |
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We introduce a new high-performance nonlocal filter, NESMA, for noise reduction in multispectral (MS) MR imaging. Through extensive analysis, we show that the NESMA filter demonstrates a high degree of overall image denoising while preserving edges and small structures. We compared the performance of the NESMA filter to the multispectral nonlocal maximum likelihood (MS-NLML) filter. Although the MS-NLML filter is highly efficient, it requires extensive computational time. NESMA markedly decreases computation time while maintaining comparable levels of noise reduction and feature preservation. Finally, we show that adaptive selection of similar voxels further improves filtering quality. |
| 1434 | Inversion quality independent robust $$$T_1$$$-quantification of MOLLI sequence data | |
1Experimental Physics V, Universität Wuerzburg, Wuerzburg, Germany, 2University Hospital Wuerzburg, 3University Hosptial Wuerzburg |
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Quantitative mapping of the longitudinal relaxation time has gained increasing interest as it allows monitoring of important structural and functional information of the myocardium. The MOLLI sequence commonly used in clinical research requires a high quality of the inversion pulses for unbiased quantification which is non-trivial especially at high fields. In this work we present a simple modification of the MOLLI sequence which in combination with the recently introduced IGF post processing solves the problem of insufficient inversion quality as demonstrated in phantom experiments. |
| 1435 | Improved Infant MRI Brain Extraction utilizing Clustering and Morphological Approaches | |
1The Developing Brain Research Laboratory, Children’s National Health System, Washington, DC, United States |
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Accurate brain extraction is a key procedure in neuroimage analyses. This paper aims to solve the intracranial cavity overestimation issue inherent to existing brain extraction methods when applied to |
| 1436 | SNR-Weighted Regularization of ADC Estimates using Double-Echo in Steady-State | |
1Radiology, Stanford University, Stanford, CA, United States |
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Double-echo in steady-state (DESS) is a 3D sequence which offers both morphological images and quantitative parameter maps (SNR-efficient 3D maps of T2 and apparent diffusion coefficient (ADC)) in various applications, such as breast imaging or knee cartilage imaging. The sequence has less sensitivity to ADC than to T2, sometimes leading to noisy ADC maps. Here, we investigate the effects of using regularized fitting of the signals, with a penalty in ADC variability, to produce less noisy ADC maps. The method is designed to apply less regularization to regions with high SNR. The approach makes use of a recent analytical expression for a ratio between DESS signals. |
| 1437 | Optimal contrast enhancement of blockface images for MRI guided reconstruction of mouse brain volumes | |
1Department of Health Science and Technology, Aalborg University, Aalborg, Denmark, 2Centre for Advanced Imaging, University of Queensland, Brisbane, Australia |
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Blockface imaging can improve atlases of the rodent brain by supplying high resolution images. This study compares three different contrast stretching methods for enhancing the information in blockface images together with a registration to a 16.4 T atlas of the mouse brain. Contrast enhancement technique used was histogram equalization, adjusting the image intensity values by stretching them between the bottom 1% and the top 1% and CLAHE with a clip limit of 0.01 and a uniform histogram. Registrations was rigid, affine and SyN. By using CLAHE as contrast stretching method a high similarity to the MRI was found. |
| 1438 | B0 Field Inhomogeneity Corrected Quantitative Susceptibility Mapping | |
1Electrical engineering, Kwangwoon University, Seoul, Korea, Republic of, 2Korea Basic Science Institute, Ochang, Korea, Republic of |
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QSM is a method that generates internal susceptibility distribution of subject using material’s intrinsic magnetic susceptibility property. Bo inhomogeneity affects magnitude and phase images. In this study, QSM with B0 field inhomogeneity correction is proposed. Using numerical simulation and in-vivo experiment, proposed method is verified. In simulation, improved susceptibility map is obtained with less root mean square error. In in-vivo experiment, signal loss and non-uniformity at frontal lobe are reduced. As field inhomogeneity increases according to the increase of main field strength, this method would be a more important element for QSM. |
| 1439 | Real-time large-scale anatomical landmark detection with limited medical images | |
1Radiology and BRIC, UNC at Chapel Hill, Chapel hill, NC, United States |
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Landmark detection based on deep neural networks has achieved state-of-the-art performance in natural image analysis. However, it is challenging to detect anatomical landmarks from medical images, due to limited data. Here, we propose a real-time large-scale landmark detection method with limited training data. We train our model with image patches and test it with the entire image, inspired by fully convolutional networks. Also, we develop a weighted loss function in our model to increase the correlations between image patches and their nearby landmarks. The experimental results of detecting 1741 landmarks from brain MR images demonstrate the effectiveness of our method. |
| 1440 | A fully automatic prostate segmentation method for both DWI and T2WI | |
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, People's Republic of China, 2Department of Radiology, Peking University First Hospital, Beijing, People's Republic of China, 3Philips Healthcare, Suzhou, People's Republic of China, 4College of Engineering, Peking University, Beijing, People's Republic of China |
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Automatic prostate segmentation in MR images is a meaningful work, not only can be used in the first step of the Prostate Imaging Reporting and Data System, but also helps to predict pathologic stage of disease by determining the prostate volume. Here we show a novel new method can get the prostate contour for both T2WI and DWI fast and accurately without any manual intervention. The segmentation accuracies for 60 images are 83.7% (T2WI) and 87.1% (DWI). Even in some cases, such as prostate hyperplasia, our method shows good robustness. |
| 1441 | Fast fitting method for simultaneously quantifying multiple MR parameters using local optimization method with predetermined initial values | |
1Research & Development Group, Hitachi, Ltd., Tokyo, Japan |
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A fast fitting method for quantifying multiple MR parameters using local optimization method with predetermined initial values is proposed. In the proposed method, an optimal neighborhood solution is extracted as predetermined initial values. A difference in MR parameters between the proposed method and the conventional method was less than 5 %. On the other hand, a computing time of the proposed method was approximately 15 times faster compared with the conventional method. We concluded that the proposed method can provide fast fitting process while maintaining calculation accuracy. |
| 1442 | Improved image texture features by Gaussian mixture models of grey-level co-occurrence matrices | |
1Department of Radiation Sciences, Umeå University, Umeå, Sweden, 2Akademiska Hospital, Uppsala, Sweden |
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Image texture features based on gray-level co-occurence matrices (GLCMs) are useful in e.g. the analysis of MR images of tumours. However, the features can be quite sensitive to the number of grey-levels in the analysed image, in particular if the region of interest is small. In this work we propose a new method for computing the GLCM, based on Gaussian mixture models. The results show that the new method improves the estimation of the GLCM and at the same time eliminates the difficult task of selecting the number of grey-levels. |
| 1443 | Optimization of 2D registration using minctracc on myelin stained brain slices | |
1Department of Radiologic Technology, Carinthia University of Applied Sciences, Klagenfurt, Austria, 2Institute for Applied Research on Ageing, Carinthia University of Applied Sciences, Klagenfurt, Austria, 3Center for Brain Research, Medical University of Vienna, Vienna, Austria, 4Medical Physics Group, Institute for Diagnostic and Interventional Radiology, Jena University Hospital – Friedrich Schiller-University, Jena, Germany, 5Centre for Advanced Imaging, University of Queensland, Brisbane, Australia, 6Montreal Neurological Institute, McGill University, Montreal, Canada, 7University Clinic for Trauma Surgery, Medical University Vienna, Vienna, Austria, 8High Field Magnetic Resonance Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria, 9Department of Medical Engineering, Carinthia University of Applied Sciences, Klagenfurt, Austria, 10Center of Anatomy and Cell Biology, Medical University Vienna, Vienna, Austria |
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Histological analyses are important for a wide spectrum of in vivo and in vitro imaging projects. But unlike MRI or CT, histological analyses are typically performed in two dimensions. Nonlinear tissue deformation and ruptures of brain tissue are often common, making analysis in slice direction more difficult. In this work, we optimized a hierarchical, nonlinear fitting pipeline on the basis of two high resolution, myelin stained brain sections using mintracc. |
| 1444 | Comparison of MP2RAGE-based morphometry methods for anorexia nervosa | |
1Advanced Clinical Imaging Technology, Siemens Healthcare HC CEMEA SUI DI PI, Lausanne, Switzerland, 2Department of Radiology, CHUV, Lausanne, Switzerland, 3LTS5, EPFL, Lausanne, Switzerland, 4Department of Neuroradiology, Geneva University Hospital, Geneva, Switzerland, 5Department of Psychiatry, Geneva University Hospital, Geneva, Switzerland, 6Department of Radiology and Medical Informatics, University of Geneva, Geneva, Switzerland |
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We explore the sensitivity of a morphometry tool to detect anorexia-related brain atrophy in MP2RAGE images. We compare volumetry resulting from two previously reported morphometry strategies on 16 patients with clinical suspicion of anorexia and identify both similarities and differences in brain atrophy evaluation. |
| 1445 | Bias and SNR of $$$T_1$$$ estimates derived from joint fitting of actual flip-angle and FLASH imaging data with variable flip angles | |
1Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States |
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Previous work has suggested fitting joint AFI/FLASH data for T1 and B1+ by minimizing the 2-norm of the difference between the signal model and measurements will produce unbiased estimates of T1. We demonstrate that, contrary to previous results, the estimator has a substantial bias that varies with both the true T1 and B1+, and the receive channel count. We also demonstrate that the correct ML estimator removes the effect of channel count, and that the choice of AFI protocol has a larger impact of the quality of estimates than the addition of an extra FLASH scan. |
| 1446 | Quantification of iron liver with clinical MRI protocols | |
1Sorbonne University, Université de technologie de Compiègne CNRS UMR 7338 Biomechanics and Bioengineering, Compiègne, France, 2Echosens, R&D Department, France, 3Radiology, ACRIM, Polyclinique Saint Côme de Compiègne, France |
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Iron quantification has been assessed through the development of magnetic resonance sequences. The purpose is to improve the existing MRI iron protocols to better diagnose the degree of hemochromatosis. Five volunteers with healthy livers underwent four protocols for the quantification of iron overloads concentration (IOC). The results have demonstrated that existing clinical protocols could be improved to provide spatial distribution of iron within one slice and all over the entire liver volume. IDEAL-IQ® could be the best protocol to have IOC volume representation with a short time of acquisition and standard deviation values associated to mean IOC data. |
| 1447 | Harmonization for cortical thickness across sites in multi-center MRI study | |
1Brain Decoding Research Center, Northwestern Polytechnical University, Xi'an, People's Republic of China, 2Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, People's Republic of China, 3MR Research China, GE Healthcare, Beijing, People's Republic of China, 4Department of Radiology, Xijing Hospital, the Fourth Military University, Xi'an, People's Republic of China, 5Department of Diagnostic Radiology, Xi'an Children Hospital, Xi’an, People's Republic of China, 6Department of Radiology, Xi'an Gaoxin Hospital, Xi'an, People's Republic of China, 7CT MR Department, the People's Hospital of Shaanxi Province, Xi'an, People's Republic of China |
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Cerebral cortex encodes crucial information of brain development, cytoarchitecture and function. However, varying data acquisition conditions at different centers could hamper group-wisely statistical analysis. This study aims to test the consistency of cortical thickness in the human brain across four sites and harmonize the deviations. Our results showed that variation of cortical thickness across sites were regionally independent, and deviation across centers could be reduced by linear regression method at a global scale, while the variations across subjects were well preserved. Those results suggest that our method has the promise in harmonizing cortical thickness measures in multi-center study. |
| 1448 | QEMDIM : Quality Evaluation using Multi-DIrectional Filter for no-reference MR image | |
1School of Electrical and Electronic Engineering, Yonsei University, Seoul, Korea, Republic of |
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This paper proposes a new image quality assessment (IQA) for no-reference MRI, Quality Evaluation using Multi-DIrectional filters for MRI (QEMDIM), that is obtained from difference of statistical features between test images and numerous pre-scanned images in Mean Subtracted Contrast Normalization (MSCN) coefficient and Multi-Directional Filtered Coefficients (MDFC). the proposed method is capable of detecting various types of artifact and can be applied to clinical applications as well as being used to evaluate the performance of MRI hardware and software |
| 1449 | Diagnostic performance of texture analysis on MRI in differentiated degree of head and neck carcinoma | |
1Peking Union Medical College Hospital, Beijing, People's Republic of China |
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The aim of this study was to determine the diagnostic accuracy of pathological differentiated degree of head and neck squamous cell carcinoma (HNSCC) using MRI texture analysis. The following texture analysis parameters were derived from the T1WI, T2WI , T2fs and Post-Gad T1WI based on different scale: entropy , mean pixel intensity, standard deviation(SD), skewness, and kurtosis. ROC curves and AUC of each parameter was determined, respectively. We conclude that the entropy at fine texture scale on Post-Gad T1WI had the best ability . |
| 1450 | Regional variations in cerebral venous contrast using susceptibility-based MRI | |
1Monash Biomedical Imaging, Monash University, Clayton, Australia, 2Faculty of Information Technology, Monash University, Clayton, Australia, 3Monash Imaging, Monash Health, Clayton, Australia, 4The Australian eHealth Research Centre, CSIRO Health and Biosecurity, Australia, 5Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia, 6Monash Immersive Visualisation Platform, Monash University, Clayton, Australia, 7ARC Centre of Excellence for Integrative Brain Function, Melbourne, Australia |
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In this study we compared the image contrast properties of susceptibility-weighted imaging (SWI) and quantitative susceptibility mapping (QSM) for cerebral venous identification and visualisation. SWI and QSM are minimally invasive techniques to image cerebral veins with distinct contrast properties. We hypothesised that these techniques would provide complementary vein contrast in different brain regions. Contrast was measured using 1072 manually traced vein images from ten volunteers. We found regional variations in the predictive power of vein contrast and computed maps of contrast profiles that may inform which technique is best for a given application. |
| 1451 | Quantitative and qualitative evaluation of bias field correction methods | |
1Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Germany, 2Center for Behavioral Brain Sciences, Magdeburg, Germany, 3Leibniz Institute for Neurobiology, Magdeburg, Germany, 4German Center for Neurodegenerative Disease (DZNE), Magdeburg, Germany |
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Bias field correction is an essential prerequisite for image analysis, especially at high field strength. In this study multiple correction methods, based on acquisition of a reference image and computational approaches with varied input parameters, are compared. The results indicate that acquisition of a conventional MPRAGE corrected by SPM yields quantitatively and qualitatively comparable results to acquiring a reference image (e.g. MP2RAGE), however, scan time is up to halfed. |
| 1452 | Rapid registration of EPI to high-resolution structural images | |
1Department of Biomedical and NeuroMotor Sciences, University of Bologna and Functional MR Unit, Policlinico S. Orsola - Malpighi, University of Bologna, Bologna, Italy |
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Post-processing methods that can non-linearly register diffusion-weighted EPI data to high-resolution images are useful in the context of clinical protocols. The current research attempts to apply currently available registration methods to rapidly perform such registration. Investigations on healthy subjects show that an appropriately generated target image allows good quality registration to be performed even with freely available software. This is useful for example to provide cortical seeds for diffusion tractography. |
| 1453 | A graphical programming environment for creating and executing adaptive MRI protocols | |
1Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, TX, United States, 2Texas Advanced Computing Center, University of Texas at Austin, Austin, TX, United States, 3Philips Healthcare, Cleveland, OH, United States |
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Inline processing of magnetic resonance images allows fast feedback of analysis and immediate access to quantitative information. It further allows the development of adaptive MRI protocols. Here, we present GRAPE, a development platform for graphical programming to facilitate the development of adaptive magnetic resonance imaging (MRI) protocols. This platform provides tools to enable graphical creation, execution, and debugging of image analysis algorithms integrated with the MRI scanner, all within a graphical environment. GRAPE is demonstrated with the implementation of patient-specific optimization of the scan parameters of 3D fluid-attenuated inversion recovery (FLAIR) protocol to enhance the contrast of brain lesions in multiple sclerosis, performed on a 3.0 Tesla MRI scanner. |
| 1454 | Validation of CSF based calibration for accurate and robust quantification of water content. | |
1Medical Imaging Physics, Institute of Neuroscience and Medicine, Juelich, Germany, 2Faculty of Medicine, RWTH Aachen, JARA, Aachen, Germany |
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Estimating tissue water content is challenging. Reliable quantification of the water content requires significant number of corrections and calibration to a reference. In this work, we proposed to use a region in cerebrospinal fluid for robust calibration; this is further validated in a cohort of healthy volunteers and compared to existing methods. |
| 1455 | Automatic nonlinear transformation of 7T MRI brain image to Talairach stereotaxic space | |
1Cleveland Clinic, Cleveland, OH, United States |
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Transforming MRI brain images into Talairach space will greatly facilitate the comparison of neuroimaging research results across subjects and applications of atlas to research subjects and clinical patients. We developed an automatic processing pipeline based on nonlinear registration to transform 7T MRI brain images to Talairach space. The pipeline utilized matching scores derived from brain parcellation for quality assurance (QA). The pipeline was tested on subjects including five controls, three MS patients and three ALS patients. The results showed that the method generated better results than the automatic Talairach transformation provided by AFNI. The QA scores were also comparable to those computed from 3T MRI brain images in our previous study. |
| 1456 | Epilepsy Surgery Followup: Resected Tissue Analysis and Classification | |
1Department of Physics, University of São Paulo, Ribeirão Preto, Brazil, 2Clinical Hospital of the Faculty of Medicine, University of São Paulo, Ribeirão Preto, Brazil |
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Focal cortical dysplasia (FCD) is one of the main causes of refractory epilepsy. There is no self-sufficient method in order to evidence the presence and location of FCD, making complete diagnosis very difficult. Although some studies have addressed FCD identification, image texture is poorly explored. This study evaluated pre and post-surgical magnetic resonance images (MRI) of epilepsy patients in order to test Machine Learning classifiers and their ability to identify dysplasia using texture features and cortical thickness. Precision and recall scores suggest the capabilities of the proposed methodology in responding to the presence of FCD tissue. |
| 1457 | Optimization of multiple orientation QSM for building a clinically feasible protocol | |
1Center for Neuroscience and Regenerative Medicine, National Institute of Helath, Bethesda, MD, United States |
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Quantitative Susceptibility Mapping (QSM) offers unique, quantitative information about tissue magnetic susceptibility. A multi-orientation method, calculation of susceptibility through multi-orientation sampling (COSMOS), enables the dipole inversion by acquiring data at multiple orientations. In practical imaging settings, however, it is a challenge to image the subject multiple orientations. Although small angle COSMOS has been shown to generate reasonable QSM images, the selection of orientations within a practical acquisition protocol remains an open question. In this work, we investigated the influence of the number and direction of orientations on the outcome of small angle COSMOS for in vivo imaging. |
| 1458 | Differences in parameter sensitivities of GESFIDE MR signals generated on realistic angiograms and on idealized cylinders | |
1Electrical engineering, Ecole Polytechnique Montreal, Montreal, QC, Canada, 2Radiology, Harvard Medical School, Massachusetts General Hospital, MA, United States |
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Idealized models of cylinders for the vasculature are used in several quantitative MRI techniques such as for perfusion, CBV, vessel size and vascular MR fingerprinting. While limitations of these models are recognized, a direct comparison of the predicted MR signal between different cylinder models and those using a real vasculature as substrate has not been done to our knowledge. Here we compare the sensitivity of the MR signal for the GESFIDE sequence for 4 sets of , models of cylinders and 6 realistic angiograms from mouse somatosensory cortex. In general, simulation results are all different between the different angiograms and the different models of cylinders. This suggests that much care should be used in interpreting literature results based on models of cylinders, or as well with models on angiograms, to account for the possibility of biases in the absolute results. Correlations and differences in absolute values, for some parameters, may perhaps be less subject to bias. |
| 1459 | Adaptive Magnetic Resonance Image signal enhancement using squared eigenfunctions of the Schrodinger operator | |
1Computer, Electrical and Mathematical Science and Engineering (CEMSE) division, King Abdullah University of Sciences and Engineering (KAUST), Thuwal, Saudi Arabia, 2Department of Radiology, University of Gent, Gent, Belgium |
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The main of challenge of Magnetic Resonance Imaging (MRI) is dealing with high levels of noise which may corrupt the image especially since the noise is almost correlated with the image details. In this regard, we propose a new MRI enhancement method to overcome this limitation. The proposed MRI enhancement method relies on square sub-images enhancement depending on the noise level in each position using spatial adaptation of the Semi-Classical Signal Analysis (SCSA) method, where an enhancement parameter h is subject to a Gaussian distribution. The results show significant improvement in noise removal and preserving small details in the image. |
| 1460 | Obtaining accurate and fast unwrapped phase images | |
1NMR Unit, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany |
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The unwrapping of phase data is a common problem in MRI. However, its solution is non-trivial for 2D or 3D images, and there has been some general research in this direction, notably in the field of optics. The two most pupular algorithms for MRI applications are: (i) a Laplacian-based method that is fast but inaccurate; (ii) a region-merging optimization method that is accurate but very slow. Here, we propose the adoption of a recently developed and freely available unwrap algorithm that significantly outperforms the other considered methods, allowing for both fast and accurate calculation of unwrapped phase images. |
| 1461 | Spatial resolution properties of QSM images using MEDI algorithm | |
1Electrical and Computer Engineering, UNIST, Ulsan, Korea, Republic of |
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We investigated the spatial resolution of the MEDI reconstructed QSM images by deriving an analytical expression of the estimator in terms of the true QSM image. The implication of this expression is that no regularization will be applied to some part of the QSM images if the corresponding magnitude image area contains strong edges and relatively strong regularization will be applied to some part of the QSM images if the corresponding magnitude image area contains low magnitude values. Our simulations with a phantom and a in-vivo QSM image confirm this analysis; Impulse perturbations were suppressed on the area where the magnitude image has low contrasts and impulses were preserved on the area where the magnitude image has high contrast or edges. |
| 1462 | AWESOME-Based De-Noising of Complex-Valued fMRI Time Series | |
1NMR, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Section on Functional Imaging Methods, National Institute of Mental Health, Bethesda, MD, United States |
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In this study we investigate possible benefits of an application of ‘AWESOME’ de-noising on fMRI. The application in a high-SNR finger tapping experiment showed a reduction of the already low thermal noise contribution and therefore improvement of tSNR and reduction of false positives; no adverse effects in the form of smoothing or suppression of ‘true’ activation was observed. A second investigation of the scalability of tSNR improvement on a resting state experiment with variable slice thickness / SNR showed that thermal noise can be reliably reduced and the tSNR proportionally improved without visible reduction of detail sharpness / resolution. |
| 1463 | Assessment of interplatform reproducibility of T1 quantification methods used for DCE-MRI: results from a multicenter phantom study | |
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Radiology, Groupe Hospitalier Pitié Salpêtrière, Paris, France, 3Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, 4Radiation Oncology, University of Michigan, Ann Arbor, MI, United States, 5Physical Measurement Laboratory, National Institute of Standards and Technology (NIST), Boulder, CO, United States, 6Radiology, University of Michigan, Ann Arbor, MI, United States, 7Radiology, Brigham and Women's Hospital, Boston, MA, United States, 8Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, 9Radiology, University of California San Francisco Mount Zion Hospital, San Francisco, CA, United States, 10Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 11Biomedical Engineering, University of Texas at Austin, Austin, TX, United States |
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Our multicenter study examined variability in T1 quantification by testing common inversion-recovery spin echo and variable flip angle (VFA) protocols, as well as T1 mapping methods used by participating sites, using a phantom with known T1 values. We found field strength dependence of the accuracy, and platform dependence of the repeatability of T1 measurements with the common VFA protocol. Accuracy for site-specific protocols was influenced by site, while repeatability, by type of protocol. Our findings suggest modified IR methods and VFA protocols with multiple flip angles and B1 correction as good methods for repeatable T1 measurement. |
| 1464 | Bio-inspired optimization of technical fiber-reinforced ramifications using high-resolution MRI of Dracaena marginata branchings as concept generators | |
1Botanical Garden, University Freiburg, Plant Biomechanics Group, Freiburg, Germany, 2Freiburg Centre for Interactive Materials and Bioinspired Technologies (FIT), Freiburg, Germany, 3Freiburg Centre for Interactive Materials and Bioinspired Technologies (FIT), Freiburg, 4Competence Network Biomimetics, Germany, 5Karlsruhe Institute of Technology, Institute of Microstructure Technology, Eggenstein-Leopoldshafen, Germany, 6Department of Radiology University Medical Center Freiburg, Medical Physics, Freiburg, Germany |
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MRT is still a little-known and highly underestimated imaging method within the field of functional morphology and biomechanics of plants and biomimetics. Its non-invasive and non-destructive character in combination with a large variety of applicable imaging sequences, gives this method a strong potential to shed light to various unanswered scientific questions concerning both the plant structure and function as well as on physiology. Using a Bruker Biospec 94/20 9.4T and a 3D FLASH sequence we could gain new insights into the biomechanics and development of dragon tree ramifications as a source of inspiration for the optimization of technical fiber-reinforced ramifications. |
| 1465 | Fast Bloch-Torrey simulation of 3D RF spoiled gradient echo sequences using a number of subvoxels and molecular diffusion effect | |
1MRTechnolocy, Inc., Tsukuba, Japan, 2University of Tsukuba, Tsukuba, Japan |
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RF spoiled gradient echo sequences were studied both with experiments and Bloch-Torrey simulation. The Bloch simulation of the 256×256×32 voxel images clarified that adequate number of subvoxels were required for artifact-free images. The Bloch-Torrey simulation for one voxel magnetization clarified that adequate number of subvoxels were required for image intensity reproduction by diffusion effect. In conclusion, molecular diffusion effects are indispensable to reproduce the image contrast in SPGR. |
| 1466 | Analysis of error in Fat-Water Quantifications Originated from Models | |
1Clinical Science, Philips Healthcare, Beijing, People's Republic of China, 2Department of Radiology, Beijing Jishuitan Hospital, 3Department of Radiology, Beijing Shijingshan Hospital |
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Fat-water separation imaging methods with multi-echo acquisition require specific fat spectrum model. The optimal spectrum model to be applied relies on the fat chemical properties as well as the acquisition scheme regarding to, for example, TR and TE. Herein we exam the consequence if inaccurate fat spectrum is used in the fat quantification processing, and analyze the related errors. |
| 1467 | Liver Biopsy Analysis to Determine Fat Droplet Distribution | |
1Biomedical Engineering, University of Wisconsin, Madison, Madison, WI, United States, 2Radiology, University of Wisconsin, Madison, Madison, WI, United States, 3Medical Physics, University of Wisconsin, Madison, Madison, United States, 4School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu, People's Republic of China, 5School of Biomedical Engineering and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, People's Republic of China, 6Pathology, University of Wisconsin, Madison, Madison, United States, 7Radiology, University of California, San Diego, San Diego, United States, 8Medicine, University of Wisconsin, Madison, Madison, United States, 9Emergency Medicine, University of Wisconsin, Madison, Madison, United States |
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The purpose of this work was to quantify the size and clustering of fat droplets using liver biopsy, as part of a long-term effort to characterize the relationship between tissue microstructure and quantitative MRI signals in fat-containing tissue. Three H&E stained liver core biopsies with varying fat-fractions were analyzed using segmentation software in order to generate probability density functions for fat droplet size and location. This work demonstrates that fat droplet distribution in the liver can be modeled statistically to determine the size and location distribution of fat droplets, potentially enabling characterization of the MR signal observed from fatty liver. |
| 1468 | Diffusion effects on T2 relaxometry with triple echo steady-state free precession sequence | |
1Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China |
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In this study, the underestimation of T2 by TESS was revealed through simulation and phantom study. The bias becomes significant in high resolution TESS imaging with larger unbalanced gradient moment, as the diffusion effect can not be neglected. A possible correction scheme was also proposed, the results validated the diffusion effect on T2 estimation. However, the correction method relies on T1/T2/D as priori to calculate the signal change ratio through EPG algorithm. A possible solution might be simultaneous estimation on apparent diffusion coefficient and T2. |
| 1469 | Brain activity alteration during the training period of the Hybrid Assistive Limb® (HAL) for chronic spinal cord injuries: a task-based fMRI case report | |
1Center for Cybernics Reseach, University of Tsukuba, Tsukuba, Japan, 2Graduate School of Comprehensive Human Science Majors of Medical Sciences, University of Tsukuba, Tsukuba, Japan, 3Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan, 4Department of Neurosurgery, Ibaraki Prefectural University of Health Sciences, Inashiki, Japan, 5Faculty of Engineering, Information and Systems, University of Tsukuba, Tsukuba, Japan, 6Department of Radiology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan, 7Department of Orthopaedic Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan |
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We previously developed the novel brain phantom showing image contrast and construction similar to those of in vivo MRI. This phantom has the potential to quantitatively assess the capability of the motion-corrected PROPELLER technique, which has been never approached. In the current study, we investigated the rotational frequency dependencies of the different two motion-corrected PROPELLER techniques by using our brain phantom. Our findings allow to quantitatively assess the capability of the Motion-Correction in PROPELLER. |
| 1470 | Determining the Time Efficiency of Quantitative MRI Methods using Bloch Simulations | |
1Quantitative Imaging, Delft University of Technology, Delft, Netherlands, 2Biomedical Imaging Group, Erasmus Medical Center, Rotterdam, Netherlands, 3Radiology, Academic Medical Center, Amsterdam |
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When measuring $$$T_1, T_2, T_2^*, PD$$$, or $$$B_1^+$$$, we prefer the MRI sequence that provides the best precision in the allowed scan time (i.e. having optimal time efficiency). However, experimentally determining the time efficiency is impractical when comparing many sequences, each possibly with varying settings, and multiple tissue types of interest. Here, we derive time efficiency through Bloch simulations which is applicable to any MRI sequence and tissue type. A specific strength of our framework is that it does not require an explicit fitting procedure which may not yet exist when designing novel MR sequences. |
| 1471 | Quantitative DCE-MRI Accuracy Evaluation Using Dynamic Physical vs. Digital Phantom: a Cross-Validation | |
1Radiology, Mayo Clinic Arizona, Scottsdale, AZ, United States, 2Radiology, Mayo Clinic Arizona, Phoenix, AZ, United States, 3Radiology-Diagnostic, Mayo Clinic, Rochester, MN, United States |
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To study the image accuracy of quantitative DCE-MRI a digital phantom and computer simulation were usually used. To validate the digital phantom method, we conducted a cross-validation study comparing the image accuracy estimation from simulation with that from a dynamic physical phantom with contrast infusion. Results showed that the estimated errors were usually higher with the physical phantom, likely due to the difference in reproducibility. Consistency was found in the measurement error comparison between imaging techniques when the temporal resolution was high. |
| 1472 | Early enhancement in breast DCE-MRI is sparse and can be imaged with a reduced FOV to increase temporal resolution | |
1Radiology, University of Chicago, Chicago, IL, United States |
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Early enhancement in breast DCE-MRI is very sparse, if the FOV is reduced in these images and aliasing occurs, the likelihood that two significantly enhancing voxels overlap is low. We present a method for ‘unfolding’ of aliased DCE-MRI acquisitions that closely approximates fully-sampled acquisitions. This method could be used to increase the temporal resolution of DCE-MRI at very early times when enhancement is rapidly changing, allowing for the accurate measurement of early lesion kinetics. |
| 1473 | Simulation of Sound Pressure Level of MRI Scan Considering Eddy Currents | |
1Medical Systems Research Department, Research & Development Group, Hitachi, Ltd., Tokyo, Japan |
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Since optimal waveforms should be chosen for each gradient pulse in order to reduce sound pressure levels (SPLs) in MRI scans, the simulation accuracy of the SPL must be improved. Assuming that the eddy current component is a cause of the disagreement between the measured and the simulated SPLs, we compared the simulation results with and without the eddy current component in this study. By including the eddy current component in the simulation, the magnitude of the SPL decreased, which reflects the decrease in the peak amplitude of the frequency component of the gradient waveform. However, the eddy current component did not affect the change trends of the SPLs depending on the change of waveforms. On the other hand, a slight change in the peak position of the frequency response functions appears to cause a significant change in the SPL, and the error of the FRF was also thought to cause disagreement between the measured and simulated SPLs. |
| 1474 | The effect of MR noise and resolution on textural features in simulated and real textures: implications for clinical practice. | |
1The Royal Marsden NHS Foundation Trust, London, United Kingdom, 2Institute of Cancer Research, United Kingdom |
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Sensitivity of textural features to acquisition parameters has important clinical implications. The aim of this study is to investigate the effect of noise and resolution on textural features. We compared textural features from a uniform and simulated texture, varied with noise, with experiment in a uniform phantom and organic texture. Our data demonstrate that a uniform texture behaves as if it has inherent texture, due to presence of artefact, and this in turn will influence textural features as noise and acquisition parameters are varied. We note that certain textural features used in clinical practice vary widely with image noise, whereas others appear to be robust. |
| 1475 | Quantification of contrast agent-induced enhancement of brain lesions in multiple sclerosis | |
1Department of Neurology, University of California San Francisco, San Francisco, CA, United States, 2Department of Cell Biology and Anatomy, National Cheng Kung University, Tainan, Taiwan |
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Contrast agents are routinely used in MRI to detect and evaluate tissue lesions. Conventional clinical protocols use T1-weighted sequences to visualize Gd contrast agent enhancement. Because T1-weighted MRI does not produce quantitative measurements, it is difficult to describe the lesion enhancement in quantitative terms and to infer the degree of the underlining disease activities of the lesions. A fast, whole-brain high-resolution T1 mapping method was developed to address this problem and applied to multiple sclerosis. |
| 1476 | LEI-ALOHA – Magnetic Resonance Imaging in the Tropical Island Setting | |
1Scannexus BV, Maastricht, Netherlands, 2Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands |
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While there are exceptions, most major MRI research centers are located in urban areas where a sizeable population is served by a large medical infrastructure and/or university. For researchers and technical staff alike, this often precludes the possibility of combining their research program with a remote, island-based lifestyle. Here we propose a set of theoretical techniques that form a framework for a purely philosophical research program. |
| Exhibition Hall | Monday 8:15 - 10:15 |
| 1477 | Respiratory Self-Gating using Principal Component Analysis in 2D Golden Angle Radial Free Breathing Cine Imaging | |
1Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden, 2Department of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden |
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Due to respiratory motion, cardiac imaging is performed during breath holding. Breath holding can be strenuous, or even impossible, for patients with heart disease. We suggest a method for respiratory self-gating using a Golden Angle radial k-space trajectory and principal component analysis. Radial trajectories sample the middle of k-space, which corresponds to the large structure content of the image, each repetition time. The respiratory motion can be detected from the |
| 1478 | Free-Breathing T2-Weighted Abdominal Examination Using Radial 3D Fast Spin-Echo Imaging | |
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 and Medical Imaging, University of Virginia, Charlottesville, VA, United States, 4Department of Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands, 5Center of Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY, United States |
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A 3D fast spin-echo (FSE) sequence design for free-breathing T2-weighted abdominal examination is described. Due to use of radial stack-of-stars sampling, the sequence provides pure T2 contrast and achieves high robustness to motion, enabling that patients can be scanned during shallow breathing. Using an integrated FID navigator, the sequence can additionally be combined with the self-navigated XD-GRASP reconstruction principle for patients who perform deep breathing. Furthermore, the navigator can be used for bulk-motion detection. Initial results in a free-breathing adult volunteer are shown. |
| 1479 | Rapid Spinal Cord Imaging | |
1Radiology, Radiological Physics, University Hospital Basel, Basel, Switzerland, 2Dept. of Biomedical Engineering, University of Basel, Basel, Switzerland |
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For rapid spinal cord imaging, an inversion recovery prepared balanced steady state free precession (bSSFP) sequence with time-limited cine sampling was developed. It simultaneously acquires eight consecutive images of remarkable different tissue contrasts at 0.67mm in-plane resolution within a single measurement of only 51s per slice. The acquired images can be further combined to considerably improve the contrast to noise ratios (CNR) of the spinal cord tissues such as gray matter and white matter. Representative examples for images measured at different cervical spinal cord locations, various image combinations, and CNR gains are shown. |
| 1480 | Synthetic MRI of the spine using outer volume suppression and virtual coil concepts to further increase scan productivity | |
1Global MR Applications & Workflow, GE Healthcare, Menlo Park, CA, United States, 2Department of Imaging Physics, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States, 3SyntheticMR AB, Linköping, Sweden |
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Several methods for rapid simultaneous quantification of proton density, T1 and T2 maps from a single acquisition have emerged recently, allowing for retrospective synthesis of MR images with any desired contrast weighting from these maps. This work adapts a 2D fast spin echo based mapping method to spine MRI where scans are typically long and prone to artifacts. Outer volume suppression was incorporated to be able to save time by encoding only the anatomy of interest without aliasing concerns. Interleaved k-t sampling and virtual coil methods were explored to overcome limited coil acceleration capability and to further increase scan productivity. |
| 1481 | Three-dimensional T1-weighted spiral imaging of the spine | |
1Imaging Research, Barrow Neurological Institute, Phoenix, AZ, United States, 2Philips Healthcare, United States |
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Spine imaging requires lengthy examination times to yield sufficient SNR and to account for patient motion. Spiral MRI is a promising method for yielding high SNR acquisitions with reduced scan times and is more robust to patient motion. This work investigates the feasibility of applying spiral MRI to T1w imaging of the spine. Initial results indicate that spiral is well suited for anatomical spine imaging. |
| 1482 | Intra-Scan Center Frequency Drift Correction for 3D Spiral Exams | |
1Magnetic Resonance Technology Design Group, Barrow Neurological Institute, Phoenix, AZ, United States, 2Philips Healthcare, Cleveland, OH, United States |
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High gradient demand and heating results in a changing main magnetic field and center frequency drift during minutes-long acquisitions. Center frequency drifts on the order of tens of Hz may produce visible artifacts in images acquired with long-readout spiral acquisitions. We propose a method for removing such artifacts in spiral acquisitions by demodulating individual spiral arms using a linear interpolation of center frequency measured before and after a scan. |
| 1483 | Slice-Accelerated Single-Shot Variable-Flip-Angle Fast Spin Echo with Very Long Echo Trains | |
1Department of Biomedical Engineering, Sungkyunkwan Univiersity, Suwon, Korea, Republic of, 2Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, Korea, Republic of |
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A Fast spin echo (FSE) pulse sequence has been a main workhorse for clinical imaging due to its flexible contrast. Simultaneous multi-slice (SMS) FSE in [1] was shown to be efficient for slice acceleration without much loss of signals. Nevertheless, the previous SMS FSE methods, which employ high-flip-angle, spatially-selective multi-band RF pulses for both excitation and refocusing, still remain sub-optimal due to either high energy deposition or elongated echo spacing (ESP) and thereby limited echo train length (ETL). The purpose of this work is to develop a novel, slice-accelerated single-shot variable-flip-angle (VFA) FSE with very long echo trains, in which multi-band RF pulses are used only for excitation while short hard pulses with VFA are utilized along the refocusing pulse train, enabling very short ESP and very long ETL and thus enhancing imaging efficiency. It is shown that the proposed method makes it possible to complete whole brain imaging within 30 sec without apparent artifacts and noise. |
| 1484 | SPAMM Based Dual Current Injection to Accelerate Data Acquisition in Magnetic Resonance Electrical Impedance Tomography | |
1Electrical and Electronics Engineering, Middle East Technical University, Ankara, Turkey |
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Reducing acquisition time in magnetic resonance electrical impedance tomography (MREIT) improves signal to noise ratio and temporal resolution of measured conductivity data. On the other hand, the reconstruction accuracy of MREIT can be improved by acquiring multiple data using different current injection patterns, which in turn increases the total scan time. In this study, a novel pulse sequence is proposed to reduce the scan time in MREIT by injecting two current patterns in a single acquisition. This method is experimentally realized using a physical phantom, and its feasibility is evaluated. |
| 1485 | Full-FOV, whole-brain, half-millimetre in-plane readout-segmented EPIK for high-resolution fMRI studies | |
1Institute of Neuroscience and Medicine, Medical Imaging Physics (INM-4), Forschungszentrum Juelich, Juelich, Germany, 2Faculty of Medicine, Department of Neurology, JARA, RWTH Aachen University, Aachen, Germany |
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Since the advent of EPI, numerous approaches have been suggested to enhance its resolution for high-resolution fMRI. Recently, several methods were demonstrated for fMRI with a sub-millimetre resolution. However, none of them can achieve such resolution with a full-FOV and, at the same time, with whole-brain coverage. This work aims to develop a novel imaging method based on EPIK in combination with readout-segmentation to achieve half-millimetre resolution with a full FOV. Here, under a typical fMRI constraint (TR of 3 s), the method was shown to provide 93 slices when further combined with the multi-band technique. |
| 1486 | Diffusion-weighted Echo Planar Spectroscopic Imaging in human brain at 3T | |
1Radiological Sciences, UCLA School of Medicine, Los Angeles, CA, United States, 2School of Nursing, UCLA School of Medicine, Los Angeles, CA, United States |
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There have been only few attempts to obtain maps of the diffusion properties of brain metabolites with diffusion weighted spectroscopic imaging. In this study we developed an echo planar based diffusion weighted spectroscopic imaging (DW-EPSI) method which uses a pairs of bipolar diffusion gradient to measure the apparent diffusion coefficient (ADC) of metabolites across an entire slice. The sequence was tested and validated on phantom and five healthy volunteers. The ADC values from DW-EPSI are in agreement with previous studies. The novel technique will enable a better understanding of the intracellular metabolism and water diffusivity correlates in pathologies. |
| 1487 | Inversion Recovery with SMS PROPELLER | |
1Neuroradiology, Karolinska University Hospital, Stockholm, Sweden, 2Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden |
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We show that simultaneous multi-slice (SMS) PROPELLER can be used with inversion recovery. This is accomplished by using an adiabatic multi-band RF pulse (PINS-DANTE), an in-house developed PROPELLER sequence and a reconstruction that calibrates both in-plane-GRAPPA and slice-GRAPPA weights for all PROPELLER blade angles on a single fully sampled PROPELLER blade volume. |
| 1488 | Spectral-Model Based Undersampling of Multi-Phase MSI: Application to Diffusion-Weighted Imaging Near Metal | |
1Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 2Applications and Workflow, GE Healthcare, Milwaukee, WI |
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Diffusion weighted imaging around metal implants is a difficult task that requires a combination of multi-spectral MRI approaches with non-CPMG spin-echo refocusing techniques. Current implementations of this approach have shown promising initial clinical results. Further work on improving the acquisition efficiency of these techniques are required to achieve robust clinical viability. Here, we present an approach that utilizes the MSI spectral domain to enable spectral undersampling of diffusion-weighted acquisitions. The approach is also easily extendable to other multi-phase implementations of MSI, such as thermometry or relaxometry, where multiple volumes of data need to be acquired for quantitative computations. |
| 1489 | MR Imaging of Magnetic Ink Patterns via Off-Resonance Sensitivity | |
1Radiology, Stanford University, Stanford, CA, United States, 2Bioengineering, Stanford University, Stanford, CA, United States, 3Electrical Engineering, Stanford University, Stanford, United States |
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Printed magnetic ink creates predictable B0 field perturbations based on printed shape and magnetic susceptibility. This can be exploited for contrast in MR imaging techniques that are sensitized to off-resonance, such as fat-suppressed imaging with spectral presaturation. Magnetic ink therefore has the potential to be used in temporary tattoos for creating MR-visible skin markings of arbitrary shape and size, with applications in surgical planning, radiation therapy, tracking of joint movement, or other image registration scenarios. Here we characterize the susceptibility variations of magnetic ink and demonstrate application for MR-visible skin markings. |
| 1490 | Multiple‑TR neuronal resonance-MRI (NR-MRI) for detection of weak oscillating magnetic field | |
1Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea, Republic of, 2Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea, Republic of |
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We propose a new approach termed neuronal resonance MRI (NR-MRI) with multiple TRs for detection of weak oscillating magnetic field. NR MRI could detect signals from oscillating magnetic fields with random frequency, phase, and on/off intervals, without synchronization between MR acquisition and neuronal oscillation. The detected signals showed higher SNR with increasing number of dynamic scans, demonstrating that temporal averaging is possible with NR-MRI. Two‑TR approach showed multiple frequency components in an absolute frequency spectrum with no a priori target frequency information while suppressing the systematic noises, which warrants further investigation. |
| 1491 | Determination of the Optimum Pattern Length of MRF Sequences | |
1Philips Research Europe, Hamburg, Germany |
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An important open question in magnetic resonance fingerprinting (MRF) is the optimal choice of sequence parameters, i.e. the ideal length and shape of the pattern that defines the variation of the acquisition parameters. Here we apply a Monte Carlo based measure of sequence performance to find the optimal flip angle pattern for different pattern lengths. Afterwards, the most efficient pattern is found by evaluating these optimized sequences’ actual performance in phantom experiments using various acceleration factors. |
| 1492 | On the Influence of Intra-Voxel Dephasing in FISP-MRF with Variable Repetition Time | |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Institute for Forensic Medicine and Traffic Medicine, 3Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany |
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In this |
| 1493 | An algorithm for refocusing of T2* effects in bSSFP-MRF with relaxation corrections | |
1Physics, Case Western Reserve University, Cleveland, OH, United States, 2Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 3Radiology, University Hospitals Case Medical Center, Cleveland, OH, United States |
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It is found that bSSFP-MRF is in general subject to T2* not T2 relaxation. Like traditional bSSFP, dephasing effects of intra-voxel inhomogeneities can be refocused in bSSFP-MRF with appropriate choices in TR, TE, and FA so that parameter maps are reflective of T2 rather than T2*. An algorithm is introduced and verified in simulation for refocusing intra-voxel dephasing at TE for bSSFP-MRF with corrections to previous work for relaxation effects previously assumed as negligible. These corrections are relevant for bSSFP-MRF in which T2 is not much larger than TR to ensure that T2 maps do not contain T2* effects. |
| 1494 | Ingredients for balanced SSFP Microimaging | |
1Dept. of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2Bruker Biospin GmbH, Ettlingen, Germany, 3Department of Microsystems Engineering IMTEK, University of Freiburg, Freiburg, Germany, 4Clinics of Radiology and Nuclear Medicine, Radiological Physics, University Hospital Basel, Basel, Switzerland |
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In this work, balanced SSFP microimaging was succesfully performed in 3D (voxel size 40μm x 40μm x 94μm) and 2D (in-plane resolution 16μm x 16μm) on a 7T small animal system and a small-bore 7T spectrometer with maximally used gradient amplitude of 1.03 T/m. Key for optimzed image quality was the choice of susceptibility matched phantom materials and the proper choice of bSSFP flip angle under consideration of diffusion attenuation due to imaging gradients. |
| 1495 | Rapid background magnetic field inhomogeneity correction in MR-based oxygen imaging | |
1Neurology, Washington Univ. in St. Louis, St. Louis, MO, United States, 2Radiology, Peking University Hospital, Beijing, People's Republic of China, 3Radiology, Washington Univ. in St. Louis, St. Louis, MO, United States, 4Pediatrics, Washington Univ. in St. Louis, St. Louis, MO, United States |
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Quantitative blood oxygenation level dependent (qBOLD) technique provides an invaluable and noninvasive means for mapping brain oxygen extraction fraction (OEF) and R2’ in various neurological disorders. However, background magnetic field inhomogeneity causes errors in the measurement. In this work, we propose a triple echo asymmetric spin echo sequence with imbedded Z-shimming table to measure and correct the adversary effect of the field inhomogeneity. With both simulation and 16 patient image sets, we have demonstrated the effectiveness of the proposed technique. |
| 1496 | Improving Arterial Spin Labeling Acquisition to Reduce the Effect of Delayed Arrival Time | |
1Physics Department, University of Sao Paulo, Ribeirao Preto, Brazil, 2Internal medicine, Medical School of Ribeirao Preto, Ribeirao Preto, Brazil, 3Physics Institute of Sao Carlos, University of Sao Paulo, Sao Carlos, Brazil |
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Arterial Spin Labeling (ASL) is a powerful technique to evaluate cerebral blood flow. To analyze hemodynamics effects with ASL, multiples acquisitions over the time are realized, which is called multiphase ASL. In conventional multiphase ASL methods, the later phases has low contrast to noise ratio, so it becomes difficult to analyze it. This study purposes a solution to this problem, through a modulation in the acquisition flip angle. With this technique, the flip angle of all phases follows a modulation equation, so that the ASL signal over the phases becomes nearly constant. |
| 1497 | Territorial Arterial Spin Labeling by Using Asymmetrically RF-shimmed Labeling Pulse with 4-channel RF Transmit at 3T | |
1Healthcare Business Unit, Hitachi, Ltd., Tokyo, Japan |
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Territorial ASL (tASL) using asymmetrically RF-shimmed labeling pulse was proposed. By using 4-channel RF transmit coil, spatially asymmetric transmission was applied to pCASL pulse. Proposed method does not require longer duration of RF pulse. Also, by using knowledge of B1 map, appropriate scaling was applied to the tASL image, and labeling efficiency was consistent between nonselective ASL and tASL. Proposed method was implemented to a 3T MRI system, and demonstrated tASL in-vivo by a volunteer study. tASL of RICA, LICA, and VBA was imaged. |
| 1498 | Phase Encoding with Bloch-Siegert effect using Parallel Transmit | |
1Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT, United States, 2Neurosurgery, Yale School of Medicine, New Haven, United States |
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A gradient-free, Bloch-Siegert effect based nonlinear spatial encoding scheme was introduced for silent scanning and to eliminate gradient-induced eddy currents in conventional MRI. We implemented a phase encoding scheme with a parallel transmit system on a 7T scanner to demonstrate feasibility. As a proof of concept, we demonstrated that B-S RF pulses can easilty produce nonlinear spatial encoding for MR imaging. The SAR limitations at 7T limit the efficiency of the encoding, but suggest the feasibility of this approach at lower fields. |
| 1499 | Tri-Fast Spin Echo: A Minimalistic Cross-Platform Multi-Spectral qMRI Pulse Sequence for Routine Clinical Use | |
1Boston University, Boston, MA, United States, 2Boston University, MA, United States, 3Boston University |
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Purpose: To develop a simple and cross-platform pulse sequence that meets the following criteria: 1) all directly acquired images are clinically useful, 2) achieves minimalistic scan times, and 3) leads to excellent image quality as well as accurate MS-qMRI mapping. Methods: Tri-FSE consists of a single-echo-FSE sequence that is run in temporal concatenation with a dual-echo FSE sequence that all together generate T1-, T2, and PD-weighted directly acquired images. Results: Tri-FSE was implemented at medium and high spatial resolution at 1.5T and 3.0T. Conclusion: Tri-FSE is a dual purpose simple pulse sequence that is useful for clinical and scientific purposes. |
| 1500 | Accelerated 3D GRASE for T2 and PD Weighted High Resolution Images | |
1Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, Netherlands, 2GE Healthcare B.V., Hoevelaken, Netherlands |
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Parallel Imaging techniques have not been introduced for Gradient and Spin Echo sequences being a limiting factor for clinical use. Enabling PI for GRASE requires new view-ordering schemes that acquire an autocalibration region while simultaneously mitigating artifacts and obtaining the desired contrast. The purpose of this work is to present new 2D PI accelerated Cartesian view-ordering schemes with either T2 or PD contrast in multi-shot VFA 3D-GRASE, for relevant SAR and scan time reduction compared to 3D-FSE/TSE. |
| 1501 | A new ultrafast 3D gradient-echo-based imaging method: RASE-II | |
1Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, Korea, Republic of, 2Department of Biomedical Engineering Sungkyunkwan University (SKKU), Suwon, Korea, Republic of, 3Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea, Republic of, 4Center for Molecular and Cellular Imaging, Samsung Biomedical Research Institute, Seoul, Korea, Republic of, 5Department of Radiology, Samsung Medical Center, Sungkyunkwan University, Seoul, Korea, Republic of |
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One version of a new ultrafast gradient-echo-based 3D imaging technique using spatiotemporal encoding (RASE-II) is proposed which provides constant TE across all spins. RASE-II maintains most of appealing features of other spin-echo-based SPEN imaging methods such as no Nyquist ghosting and high tolerance to field inhomogeneities. RASE-II also has less sensitivity not only to SAR and B1-inhomogeneity effects because of low flip angles, but also to T2* signal modulation due to constant TE. As a promising tool for fMRI, RASE-II shows significant improvement of tSNR over GE-EPI. Its performance is demonstrated by lemon and in-vivo rat brain imaging at 9.4T. |
| 1502 | Dual Echo Trajectory : Comparison to Partial Fourier Acquisition and Sequence Optimization | |
1Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of |
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In this study, we compared two acceleration methods in spin echo imaging; previously proposed Dual Echo Trajectory (DuET) and partial Fourier acquisition. Also, we further improved DuET with interleaved multislice acquisition and echo timing correction. |
| 1503 | Blood saturation modeling in multiband multislab Time-of-Flight brain MRI | |
1DRF / I2BM / NeuroSpin / UNIRS, CEA-Saclay, Gif-sur-Yvette, France |
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Multiband multislab Time-of-Flight angiography has recently been proposed for reduced acquisition time and improved sensitivity in the human brain at 3T and 7T. However, in these previous studies, blood saturation has not been taken into account as blood traverses several slabs acquired simultaneously. Here a simple modeling of blood magnetization history is provided to take this saturation into account, which appears essential to avoid strong losses of blood to background signal ratio. Slab-dependent multiband-added VUSE pulses are simulated to counteract these losses both at 3T and 7T, from which a methodology is derived to optimize multiband TOF sequence parameters. |
| 1504 | Simultaneous Multi-Volume 4D Phase Contrast Flow MRI | |
1Advanced MRI Technologies, LLC, Berkeley, CA, United States, 2Helen Wills Neuroscience Institute, Univ of California, Berkeley, Berkeley, CA, United States |
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A new technique of simultaneous 4D flow imaging acquired with simultaneous multiple 3D volumes (SMV) is presented. The velocity measurements are compared to conventional 4D flow imaging and have very good correspondence. |
| 1505 | Spatial Mapping Using Radio Frequencies: A Non-Linear Approach to Silent MRI | |
1University of California Irvine, Irvine, CA, United States, 2University of California Berkeley, Berkeley, CA, United States |
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Recent advances for silent MRI have shown that spatial encoding can be achieved using RF rather than linearly varying static magnetic field gradients. This has been demonstrated using homogeneous transmit (B1) fields with linearly varying phase gradients. Similar results can be achieved with linear B1 amplitude gradients with homogeneous phase. The efficacy of either method is limited by a maximum B1 gradient strength (phase or magnitude) per specific absorption rate. Here we demonstrate a novel approach to relieve this restriction where highly nonlinear B1 gradients can be used for combined amplitude and phase modulation with reconstruction using state-of-the-art machine learning models. |
| 1506 | SNR Efficiency of Combined Bipolar Gradient Echoes: Theoretical Expressions and Experimental Verification | |
1Oncology, University of Alberta, Edmonton, AB, Canada, 2Medical Physics, Cross Cancer Institute, Edmonton, AB, Canada |
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Multi-echo bipolar pulse sequences are becoming increasingly popular in structural brain imaging applications that require high SNR efficiency and minimal geometrical distortions or water-fat shifts. However, various discrepant expressions for the SNR as a function of T2* and the sampling bandwidth were previously reported, making it unclear as to how multiple bipolar echoes should be combined to maximize SNR. In this study, we compare some traditional single-echo (low-bandwidth) FLASH and MPRAGE sequences with their multi-echo bipolar (high bandwidth) counterparts and validate the SNR theory via phantom measurements. Bipolar MPRAGE/FLASH yield SNR gains of ~1.3/1.6-fold, in good agreement with the theory. |
| 1507 | Signal Coding for SNR Multiplying Effect and Scan Acceleration Flexibility | |
1Zhu Consulting, Scarsdale, NY, United States |
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In a way that augments existing encoding, signal coding promotes a multiplying effect of SNR and flexibility of scan acceleration. Its essence is to push for noise decimation by acquiring sums of marked signals from all components where the marking can be achieved by RF, gradient or other means. Its application to multi-slice MRI opens up a regime that enjoys both a √N SNR enhancement, as analogous to that of volumetric MRI, and flexibility with scan time budget, as equal or superior to that of existing multi-slice MRI. |
| 1508 | Sequence Design by Signal Inversion Using Extended Phase Graphs | |
1Electrical Engineering, Stanford University, Stanford, CA, United States |
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In this work, we show that MR signal progression can be represented as an autonomous discrete linear dynamical system when the small angle approximation is made. This formalism can be used to determine an optimal set of flip angles to yield a desired magnetic state. We present an an example of maintaining a constant signal strength with a Fast Spin Echo sequence. |
| 1509 | GPU optimized fast Bloch simulator for arbitrary MRI pulse sequences | |
1MRTechnology, Inc., Tsukuba, Japan, 2University of Tsukuba, Tsukuba, Japan |
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A GPU optimized fast Bloch simulator was developed for arbitrary pulse sequence inputs. The simulator was applied to multi-slice imaging using 256×256×512 calculation matrix. As a result, we found that the number of short pulses used to approximate the selective excitation pulse and the number of subvoxels used for imaging in the cross-sectional plane were essential to simulation speed. |
| 1510 | MRI Pulse Sequence Development Using Graphical User Interface Modules | |
1Fraunhofer MEVIS, Bremen, Germany, 2University of Bremen, Bremen, Germany |
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We present a preliminary study on developing MRI pulse sequences using graphical user interface elements. We introduce a prototype where a sequence developer can specify a sequence structure and parameter dependencies just using the GUI. As a result, a sequence developer can concentrate on the MRI sequence design, rather than on software engineering issues. The GUI-based development framework is decoupled from the manufacturer’s development environments and promises to promote the development of basic sequence designs that are independent of the scanner platforms used. |
| 1511 | Assessing intrinsic velum height in vowels using time-resolved MRI | |
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany, 2Institut für Germanistische Sprachwissenschaft, Friedrich Schiller University Jena, Jena, Germany, 3Michael Stifel Center for Data-driven and Simulation Science Jena, Friedrich Schiller University Jena, Jena, Germany, 4Abbe School of Photonics, Friedrich Schiller University Jena, Jena, Germany, 5Center of Medical Optics and Photonics, Friedrich Schiller University Jena, Jena, Germany |
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Real-time MRI and synchronised audio were used to examine intrinsic velum height in German vowels. Two adult female subjects produced five repetitions of a set of sentences containing, among other target material, the point vowels /i: a: u:/ in the same phonologically non-nasalised context. Even in this small sample, the subjects exhibit variation in velum height across vowel categories, and show considerable interindividual variation in velum height during the production of the same vowel category. Collection of further data from normal subjects will be used to create a robust baseline for the assessment of abnormal velum activity. |
| Exhibition Hall | Monday 8:15 - 10:15 |
| 1512 | Strategies for Compensating for Missing k-space Data in a Novel Half-Fourier Reconstruction | |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States |
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Functional MRI (fMRI) is sensitive to off-resonance from air-tissue susceptibility interfaces. Existing half-Fourier reconstruction is vulnerable to off-resonance since it may lose most of the image energy (near k=0) with a large amount of off-resonance. In a previous study, we suggested a new half Fourier (even/odd (E/O)) reconstruction and showed it was more robust to off-resonance compared to Homodyne reconstruction. E/O reconstruction acquires every other line in k-space. Therefore, neighboring data can be used to compensate for the missing data. In this study, we suggest several strategies for compensating for missing k-space data in kx-ky as well as kz direction. |
| 1513 | Reducing acquisition time while maintaining spatial resolution with extended readouts and R2* modeling | |
1Bioengineering, 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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Single shot readouts are limited in length by field inhomogeneity and R2* relaxation. With the inclusion of a complex field map, existing field corrected reconstruction algorithms can compensate for both field inhomogeneity and R2* relaxation during extended readouts. Results for spiral acquisitions of up to 56ms in length are demonstrated on a human volunteer. |
| 1514 | Accelerated Regularized Image Reconstruction in Spatiotemporal MRI | |
1University of Minnesota, Minneapolis, MN, United States, 2Center for Magnetic Resonance Research, University of Minnesota |
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Interest in spatiotemporally-encoded MRI methods has increased over the last decade due mainly to their high tolerance to magnetic field inhomogeneities. However, the data acquired in spatiotemporal MRI can lead to challenging image reconstruction problems. In this abstract we propose a new framework for reconstructing images that leverages compressible structure in recent spatiotemporal encoding techniques to enable an iterative approximate inversion of the Bloch-equations for imaging. In particular, we can often obtain a visually indistinguishable reconstruction up to an order of magnitude faster than using the full inversion. |
| 1515 | Fast Multi-contrast MRI Super-resolution with Similar Anatomical Structure | |
1Dept. of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen 361005, China, Xiamen, People's Republic of China, 2School of Mathematical Sciences, Xiamen University, Xiamen 361005, China, People's Republic of China, 3Dept. of Computer Science, Xiamen University of Technology, Xiamen 361024, China, People's Republic of China |
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Since magnetic resonance imaging (MRI) can offer images of an object with different contrasts, e.g., T1-weighted or T2-weighted, the shared information between inter-contrast images can be used to benefit super-resolution. Regarding the image as a locally stationary Gaussian process and using the least square method, we found weights of a local window are to be nearly invariant to image contrasts, which can be further used to transfer the shared information from one contrast to another. We analyze this property with comprehensive mathematics and numeric experiments. The reconstructed edges are more consistent to the original high-resolution image, indicated with higher PSNR and SSIM than the compared methods. |
| 1516 | 7T-like MR Images Synthesis from 3T MRI using Auto-Context Convolutional Neural Network | |
1University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2Department of Brain and Cognitive Engineering, Korea University, Seoul, Korea, Republic of |
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We propose a novel multi-step Convolutional Neural Network (CNN) architecture to cascade multiple CNNs, along with an Auto-Context Model (ACM), called Auto-Context CNN, to reconstruct 7T-like MR images from 3T MR images. Basically, we non-linearly map the input 3T MR images to their corresponding 7T MR images. To do so, in the training stage, we first partition the training 3T and 7T MR images into overlapping 3D patches, then we train the Auto-Context CNN to map each 3T patch to the center voxel in the corresponding 7T patch. In the testing step, we apply the trained Auto-Context CNN to generate the 7T-like MRI patch from each input 3T patch. |
| 1517 | Evaluation of convex programming for super-resolution MRI reconstruction using shifted slice acquisitions | |
1Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States |
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Super-resolution methods have recently became popular due to their ability to generate isotropic high resolution images from multiple low resolution acquisitions. In this work, we developed and evaluated a convex programming solution to the super-resolution reconstruction and applied it to combine shifted thick slice T2 images into images with isotropic resolution. With this formulation, using phantom and volunteer experiments, we show that, it is possible to generate high resolution images with better resolution and accuracy compared to the previously developed methods. |
| 1518 | The use of SPIRIT to reject and replace motion-corrupted data | |
1Aix-Marseille Université, Marseille, France |
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The SPIRIT parallel imaging algorithm was evaluated for use in a data rejection and replacement scheme to reduce motion artefacts. |
| 1519 | A method for identifying and fixing faulty navigator corrections in system-reconstructed multi-shot 3D diffusion weighted images | |
1Department of Animal Science, The Pennsylvania State University, University Park, PA, United States, 2Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, United States, 3Huck Institutes of the Life Sciences, The Pennsylvania State University, 4Interdepartmental Graduate Program in Neuroscience, The Pennsylvania State University |
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Unusual artifacts appear in some reconstructed images of a multi-segment 3D EPI-DTI sequence with navigator correction on a 7T Bruker Biospec system running Paravision 6.1. Navigator helps to compensate for subject movement within the scanner. However, by examining the k-space of the system processed volumes and the raw navigator data, the artifacts were attributed to navigator overcompensation, which resulted in the over representation of a few lines in k-space. After zeroing the affected lines, image quality was on par with other volumes with no artifacts, eliminating the need to rescan subjects. |
| 1520 | Iterative reconstruction of highly undersampled multi-echo EPI – a novel dynamic contrast approach to tackle distortions | |
1TUM, Munich, Germany, 2GE Global Research, Munich, Germany |
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We propose a highly undersampled multi echo EPI sequence combined with a selfcalibrating reconstruction pipeline to adress offresonance artifacts. Ideas from the areas fieldmap, RPG and temporal subspace transform are combined yielding distortion free dynamic contrast images. |
| 1521 | k-t Rank Separation Reconstruction for non-Cartesian parallel fMRI | |
1Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Freiburg, Germany |
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Low-rank sparse (L-S)-reconstruction has been successfully applied to k-t-accelerated applications like cardiac cine imaging. We propose a novel way of k-t rank separation for the reconstruction of non-Cartesian parallel fMRI. Instead of reconstructing the fMRI images separately, the proposed method reconstructs images jointly. This method extracts temporal signal variation information from k-t space directly, thus exactly preserving dynamic information. The results show a higher dynamic signal recovery rate and shorter reconstruction time. |
| 1522 | SQUASHER: Slice quadratic phase with HSn encoding and reconstruction | |
1Center for Magnetic Resonance Research, Minneapolis, MN, United States, 2University of Minnesota, Minneapolis, MN, United States |
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For 3D imaging, frequency-swept excitation can be used to obtain broad bandwidth and sharp slab profiles. The quadratic phase from such RF excitation imparts spatiotemporal encoding and can be leveraged for added encoding. Here we show that, by sliding the quadratic phase across the slice-encoding direction, synergy can be achieved when combining frequency-swept excitation with Fourier encoding, which has inherent optimal noise-properties. |
| 1523 | Extraction of NMR Signal from a Portable Single-Sided Magnet System in a Noisy Environment | |
1Radiology, Brigham and Women's Hospital, Boston, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3Mirtech, Inc, Brockton, MA, United States |
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MR is a useful method for monitoring patients with pulmonary edema. To prevent difficult and costly transportation of patients to an MR imaging location, a portable magnet system was recently developed.The system necessarily operates in a noisy electro-magnetic environment,thus signal processing methods are needed to extract the NMR signal from a measurement system that is flooded with signal from external sources. This work compares a traditional adaptive filter theory approach against a sub-space projection approach. We demonstrate with phantom data measurements that these methods can improve detection of the NMR signal in anoisy environment. |
| 1524 | Pseudo-inverse constrained (PICO) reconstruction reduces colored noise of PROPELLER and improves the gray-white matter differentiation | |
1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, 2Department of Radiology, University of Cambridge, Cambridge, United Kingdom, 3Department of Applied Physics, National Chengchi University, Taipei, Taiwan, 4Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong, 5Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, 6Department of Medical Imaging, Madou Sinlau Hospital, Tainan, Taiwan, 7Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan, 8Department of Medical Imaging, National Taiwan University Hospital Yun-Lin Branch, Taipei, Taiwan, 9Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom, 10MRIS unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom |
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The image quality of Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction (PROPELLER) MRI is degraded by the “colored noise” or “blue noise”. Total variation (TV) denoising is expected to reduce colored noise and improve the overall image quality. However, no study has compared different TV algorithms for reducing colored noise. This study explores two TV denoising methods: (1) image domain denoising (IDD), and (2) Pseudo-Inverse |
| 1525 | Distortion Correction in Readout-Segmented EPI using View Angle Tilting Combined with Phase Modulated RF Pulse | |
1Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, People's Republic of China |
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The VAT technique has been applied in ss-EPI to eliminate the distortion along the phase encoding direction. However the long echo spacing in ss-EPI will lead to more phase errors introduced by B0 inhomogeneity and require more VAT gradient, which results an increasing image blurring and limits the spatial resolution. The rs-EPI features much shorter echo spacing compared with ss-EPI, which could be much suitable for VAT. In this study, the VAT technique is integrated into a rs-EPI sequence to further improve the distortion. In addition, phase modulated pulse is used to reduce the image blurring caused by VAT. |
| 1526 | An improved image-based method for field inhomogeneity map in distorted brain EPI image | |
1Department of Radiological Technology, Faculty of Health Sciences, Hokkaido University of Science, Sapporo, Japan, 2Department of Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan |
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To correct the distortion in EPI due to field inhomogeneity, an image-based method for estimating the field map from the distorted EPI image has been proposed. However, this method suffers from long computation times. Our purpose was to improve an image-based method in terms of the computation time. Whereas the previous method synthesized EPI image in k-space requiring a lot of execution of FFT, our method synthesized EPI image in the image-domain. Our method reduced the computation time in the almost same NRMSE in previous method. Our results suggest that our improved method was able to perform a reasonable estimation of the field map. |
| 1527 | Selective Channel Combination of 3D Phase Offset Corrected 7T MRI Phase Images | |
1Centre for Advanced Imaging, University of Queensland, Brisbane, Australia, 2Siemens Healthcare Australia Pty. Ltd., Australia |
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A number of MRI applications rely on accurate phase images. At ultra-high field, the limitations of various processing techniques and the absence of a volume reference coil make the combination of multi-channel signal phase challenging. We propose a method which combines phase offset corrected signal phase data across a selection of channels. We evaluated method performance at two different gradient recalled echo MRI echo times. We qualitatively and quantitatively studied the combined phase quality in distinct brain regions. We found that using a subset of channels leads to improved phase images than when all channels are used in the combination. |
| 1528 | Acceleration and Artifact Suppression in Selective TOF MRA with Sampling Reduction | |
1Healthcare Business Unit, Hitachi, Ltd., Tokyo, Japan |
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We confirmed that 2D beam excitation presaturation-pulse (hereafter BeamSat pulse) can saturate the vessels selectively in brain. Although BeamSat can visualize hemodynamics, the scan time is long (about 5 minutes) because the based sequence is 3D TOF. The single thick slice 2D TOF was used for based sequence to reduce the scan time and the ks offset was added to saturate background brain signal. We showed that this method can accelerate the scan time to 0.6-0.8 seconds without the notable loss of vessel visualization. |
| 1529 | SPARKLING: Novel Non-Cartesian Sampling Schemes for Accelerated 2D Anatomical Imaging at 7T Using Compressed Sensing | |
1CEA/NeuroSpin, INRIA/Parietal, Gif-sur-Yvette Cedex, France, 2CNRS/ITAV, Toulouse, France, 3Siemens Healthineers, Saint-Denis, France, 4CEA/NeuroSpin, Gif-sur-Yvette Cedex, France |
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We present for the first time the implementation of novel non-Cartesian trajectories on a 7T scanner for 2D anatomical imaging. The proposed SPARKLING curves (Segmented Projection Algorithm for Random K-space sampLING) are a new type of non-Cartesian segmented sampling trajectories which allow fast and efficient coverage of the k-space according to a chosen variable density [1]. To demonstrate their potential, a high-resolution (0.4x0.4x3.0mm3) T2*-weighted image was acquired with an 8-fold undersampled SPARKLING trajectory. Images were reconstructed using non-linear iterative reconstructions derived from the Compressed Sensing theory. |
| 1530 | A Blind Deconvolution Approach to Fast MR T2 Mapping | |
1Electrical Engineering, State University of New York at Buffalo, Buffalo, NY, United States, 2Shenzhen Institutes of Advanced Technologies, Shenzhen, People's Republic of China, 3Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY, United States |
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MR parameter mapping has shown great potential but is still limited in clinical application due to the lengthy acquisition time. To accelerate the acquisition speed using multi-channel coils, we propose a novel blind deconvolution based approach to parameter mapping. The proposed method reconstructs the series of T2-weighted images, coil sensitivities of all channels, and the T2 maps simultaneously through a highly efficient, k-space based blind deconvolution approach. The experimental results show the potential of highly accelerated T2 mapping by the proposed method. |
| 1531 | Alternating Direction Method of Multipliers for Diffusion Basis Functions (DBF) | |
1Centro de Investigacion en Matematicas AC, Guanajuato, Mexico |
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We propose a new framework to solve the Diffusion Basis Functions model based on the alternating direction method of multipliers. We present an iterative, simple and efficient algorithm with closed-form updates. The proposal introduces a new regularization term to promote sparsity in the number of estimated fibers. Our experimental result shows that diffusion dictionary approaches benefit from our proposal. |
| Exhibition Hall | Monday 13:45 - 15:45 |
| 31 | Free-breathing volumetric fat/water separation by combining radial sampling, compressed sensing, and parallel imaging | |
1Radiology, NYU School of Medicine, New York, NY, United States, 2Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, United States |
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Fat-suppressed T1-weighted gradient-echo imaging is commonly used for abdominal MR examination. However, image quality can be compromised by inhomogeneous fat suppression and imperfect breath-holding. To overcome both limitations, we describe a novel technique for free-breathing fat/water separation (Dixon-RAVE). Motion-robust acquisition is achieved by using radial sampling. A model-based reconstruction, which incorporates compressed sensing, parallel imaging, and fat deblurring, is used to obtain fat and water maps. Two extensions are described that enable motion-resolved fat/water separation (XD-Dixon-RAVE) and dynamic contrast-enhanced fat/water separation (DCE-Dixon-RAVE). The technique is demonstrated for various clinical applications, including free-breathing liver and breast exams in volunteers and patients. |
| 32 | Direct Quantitative 13C-Filtered 1H Magnetic Resonance Imaging of PEGylated Biomacromolecules In Vivo | |
1Department of Chemistry, University of Toronto, Toronto, ON, Canada, 2Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 3Sunnybrook Research Institute, Toronto, ON, Canada, 4Department of Biochemistry, University of Toronto, Toronto, ON, Canada |
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We demonstrate a new platform technology in which macromolecular constituents, such as proteins and drug delivery systems, are observed directly and quantitatively in vivo using 1H MRI of 13C-labeled polyethylene glycol (13C-PEG) tags. The 28 kDa 13C-PEG tags are non-immunogenic, and each bears approximately 2500 spectroscopically equivalent 1H nuclei appearing at a single resonance position. By filtering the 1H PEG signal through the directly coupled 13C nuclei, background water and fat signals are largely eliminated. We demonstrate the approach by monitoring in real-time the distribution of 13C-PEG and 13C-pegylated albumin injected into the hind leg of a mouse. |
| 33 | Hybrid MRI-ultrasound acquisitions, and scannerless real-time imaging | |
1Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States, 2The Laboratory for Imagery, Vision and Artificial Intelligence, École de Technologie Supérieure, Montréal, QC, Canada, 3Department of Physics, Soochow University, Taipei, Taiwan, 4Google Inc, New York, NY, United States |
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The goal of this project was to combine MRI, ultrasound (US) and computer science methodologies toward generating MRI at high frame rates, inside and even outside the bore. A small US transducer, fixed to the abdomen, collected signals during MRI. Based on these signals and correlations with MRI, a machine-learning algorithm created synthetic MR images at up to 100 frames per second. In one particular implementation volunteers were taken out of the MRI bore with US sensor still in place, and MR images were generated on the basis of ultrasound signal and learned correlations alone, in a 'scannerless' manner. |
| 34 | Imaging Left-ventricular Mechanical Activation in Heart Failure Patients using Cine DENSE MRI: Validation and Implications for Cardiac Resynchronization Therapy | |
1Department of Biomedical Engineering, University of Virginia Health System, Charlottesville, VA, United States, 2Medicine/Cardiology/Electrophysiology, University of Virginia Health System, Charlottesville, VA, United States, 3Radiology/Medical Imaging, University of Virginia Health System, Charlottesville, VA, United States |
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This study developed methods for imaging left-ventricular (LV) mechanical activation, with application to identifying optimal LV pacing sites for cardiac resynchronization therapy (CRT). Cine displacement encoding with stimulated echoes (DENSE) was used for strain imaging, and mechanical activation time was defined as the time of onset of circumferential shortening (TOS). Active contours were applied to strain data to automatically compute TOS. Results showed a strong correlation between TOS and electrical activation time, heterogeneity of the location of latest activation, and a significant association between TOS at the LV pacing site and CRT response. These methods may enable improved CRT implementation. |
| 35 | PET/MR Imaging of Metabolic Bone Activity in Osteoarthritis | |
1Radiology, Stanford University, Stanford, CA, United States, 22Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, Canada, 3Department of Radiology & Nuclear Medicine, Erasmus MC, University Medical Center, Rotterdam, Netherlands, 4Department of Bioengineering, Stanford University, Stanford, CA, United States, 5Department of Orthopaedic Surgery, Stanford University, San Francisco, CA, United States |
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Osteoarthritis (OA) is a leading cause of disability, resulting in reduced quality of life, at tremendous societal cost. New hybrid PET/MR systems allow for simultaneous, sensitive, and quantitative assessments of early bone activity in OA with PET, which can be correlated with high-resolution quantitative MR methods of soft tissues to study the pathogenesis of OA. We demonstrate promising initial results of simultaneous PET/MR hybrid imaging of knee OA. Results suggest that PET/MR may detect metabolic abnormalities in subchondral bone, which appear normal on MRI. These advancements will allow us to detect and track early and reversible changes in OA. |
| 36 | Quantifying the Influence of Respiration and Cardiac Pulsations on the Cerebrospinal Fluid Dynamics using Real-Time Phase-Contrast MRI | |
1Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, United States, 2Department of Mechanical Engineering, Conquer Chiari Research Center, The University of Akron, Akron, OH, United States, 3MR R&D Collaborations, Siemens Healthcare, Columbus, OH, United States, 4MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, 5Department of Biological Engineering, The University of Idaho, Moscow, ID, United States, 6Department of Radiology & Imaging Sciences and Biomedical Engineering, Emory University, Atlanta, GA, United States |
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Cerebrospinal fluid (CSF) flow undergoes periodic pulsatile motion driven by cardiac and the respiratory forces. Invasive studies using spinal taps as well as non-invasive studies using phase contrast MRI (PCMRI) sequences have well documented the cardiac-driven CSF flow. PCMRI, however, often uses a conventional cine-phase contrast technique gated to the cardiac cycle, and thus cannot measure the effects of respiration or other non-cardiac transient events such as coughing. Examining these effects requires the ability to perform real-time MRI measurements of continuous CSF flow along the spine and cranial cavity, and determine accurate instantaneous CSF flow velocity values. |
| Exhibition Hall | Monday 16:15 - 18:15 |
| 1532 | Six-month follow-up of the patients with the low-grade femoral cartilage lesions using T2 mapping at 3 and 7 Tesla | |
1Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, 2Department of Imaging Methods, Slovak Academy of Sciences, Institute of Measurement Scinece, Bratislava 4, Slovakia, 3Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland, 4Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland, 5University Clinic for Trauma Surgery, Medical University of Vienna, Vienna, Austria, 6Novartis Institutes for Biomedical Research, Basel, 7CD Laboratory for Clinical Molecular MR Imaging |
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Transverse relaxation time (T2) maps were assessed as a potential marker for the long-term follow-up of the patients with cartilage lesions ICRS Grade I-II in four time points (baseline, 8 days, 3 and 6 months). T2 mapping was based on a 3D triple echo steady state imaging sequence delivering high quality high-resolved T2 maps at ultra-high field MRI. The results showed opposite trends of T2 values at 3T (a decrease) and 7T (an increase) over time. The statistically significant difference was found in case of deep zone of the cartilage lesion at 3T. T2 mapping could be used in the future as a good alternative to cartilage biopsies in clinical trials on new therapies aimed at cartilage regeneration. |
| 1533 | Automated Segmentation of Knee Cartilage from MR Images using Sequential Multi-atlas Registration and Shape-constrained Locally-weighted Voting for Quantitative Knee Joint Assessment | |
1School of Electrical Engineering, KAIST, Daejeon, Korea, Republic of, 2Dept. of Software Convergence, Seoul Women's University, Seoul, Korea, Republic of, 3Department of Radiology, Samsung Medical Center, Seoul, Korea, Republic of |
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We propose a multi-atlas segmentation method for the knee cartilage in T2 PD MR images using sequential multi-atlas registrations and locally-weighted voting (LWV). To select training atlases similar to the test image, a 2D projection image-based atlas selection method is proposed. Then, to extract a bone model to be used as registration target in cartilage segmentation, the bone is segmented by sequential multi-atlas registrations and LWV. Finally, to segment a cartilage without leakage into low-contrast surroundings, the cartilage is segmented by bone-mask-based cartilage registration and shape-constrained LWV with distance and structure similarity weights, as well as atlas similarity weight. |
| 1534 | MR Microscopy of early changes in osteoarthritis – Ex-vivo study of the osteochondral degenerative process at 7T | |
1High Field MR Centre, Department of Biomedical Imgaing 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, 4Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia, 5Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland, 6Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria |
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Visualizing the early changes in osteoarthritis is still challenging the musculoskeletal imaging community. Especially structures of the osteochondral junction cannot be depicted by conventional MRI due to their thinness and short T2/T2* relaxation times. A variable echo time sequence in combination with high field 7T and a MR microscopy setup, allows microscopic resolution and echo times in the sub-millisecond range and can be used for visualizing short T2/T2* structures of the cartilage-bone interface such as calcified cartilage. In this study we focused on imaging early changes in osteoarthritis as approach for bringing biological information closer to clinic related applications. |
| 1535 | The effect of loading on T2* and MT ratio in tendons: A feasibility study | |
1Radiology, University of California, San Diego, San Diego, CA, United States, 2GE Healthcare, San Diego, CA, United States, 3Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States |
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UTE_MRI is assumed to be a great non-invasive technique to assess tendons as a unique viscoelastic tissue, with a very short T2. Early stage of tendon diseases, is hypothesized to affect the mechanical properties of tendon sooner and quicker than its morphology. This study, focused on the UTE-based T2* and MTR variations of the tendon samples under mechanical loading. Stretching the tendon samples with different loads using an MRI-compatible device resulted in significant reductions of T2* and increases in MTR. The MTR regional variations and shifts, obtainable by presented approach will help for assessing tendon quality and health level. |
| 1536 | The effect of loading on ultrashort echo time magnetization transfer (UTE-MT) imaging and modelling parameters in human articular cartilage: a feasibility study | |
1Radiology, University of California, San Diego, San Diego, CA, United States, 2GE Healthcare, San Diego, CA, United States, 3Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States |
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UTE_MRI is assumed to be a great non-invasive technique to assess articular cartilage (AC) as a unique viscoelastic tissue, with a very short T2. Early stage of cartilage osteoarthrosis, is hypothesized to affect the mechanical properties of AC, sooner and quicker than its morphology. This study, focused on the application of the UTE_MT modelling and MT ratio variations in femorotibial AC in loaded knee. Compressing the cadaveric human intact knee with different loads, using an MRI-compatible device, resulted in significant increases macromolecule fraction. The local MTR maxima in the AC were interestingly shifted towards the contact point after loading. |
| 1537 | Accelerated Musculoskeletal MRI using Region of Interest Compressed Sensing | |
1Medical Imaging Research Center, Dayananda Sagar Institutions, Bangalore, India, 2Healthcare, Wipro GE Healthcare, Bangalore, India |
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MusculoSkeletal (MSK) MRI is used for analyzing injuries, and the knee injury is one of the common injuries reported in sports. Current work uses Compressed Sensing (CS) based reconstruction technique called Region Of Interest Compressed Sensing (ROICS). The proposed method has been demonstrated on five datasets at chosen acceleration factors. The reconstructed images are compared with the reference images using line intensity profile and NRMSE graph to demonstrate the utility of the proposed ROICS method on MSK MRI. The qualitative and quantitative result shows that ROICS performs better than CS. Current and future work involves the prospective implementation of ROICS on MSK MRI. |
| 1538 | Algorithm for Semi-Automatic Segmentation of Hip Acetabular Cartilage Applied to Patients with Femoroacetabular Impingement | |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Consultant, Costa Mesa, CA, United States, 3Radiology, University of Minnesota, Minneapolis, MN, United States, 4Orthopaedic Surgery, University of Minnesota, Minneapolis, MN, United States |
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A new algorithm to segment the acetabular cartilage based on a single 3D DESS data set is presented. This development was motivated by a need to simplify visualization of 3D quantitative maps of acetabular cartilage damage for surgical planning and arthroscopic correlation. A rapid segmentation algorithm is an important element of this framework, which will be used to guide reparative arthroscopic surgery of patients with femoroacetabular impingement. |
| 1539 | Comparison of T1ρ quantification, SNR, and reproducibility in 3D Magnetization-Prepared Angle-Modulated Partitioned k-space Spoiled Gradient Echo Snapshots (3D MAPSS) and 3D Fast Spin Echo (CubeQuant) techniques. | |
1University of California, San Francisco, San Francisco, CA, United States |
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Though T2 cartilage mapping has been shown to be sequence dependent, few studies have looked at the inter-sequence variation of cartilage T1ρ quantification. This study compares T1ρ quantification, SNR, and reproducibility of the MAPSS and CubeQuant T1ρ sequences. Four healthy controls received unilateral knee scans. Each patient was scanned twice and was removed from the scanner between scans. Significant differences were found in T1ρ quantification with comparable SNR and reproducibility. This study highlights the importance of using same sequences for quantitative cartilage imaging in multicenter studies. |
| 1540 | Comparative T2 and T1ρ Mapping of Patellofemoral Cartilage under in situ Mechanical Loading with Prospective Motion Correction | |
1Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Freiburg, Germany, 2John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, United States, 3Department of Orthopedic and Trauma Surgery, Medical Center - University of Freiburg, Freiburg, Germany |
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Robust comparative T2 and T1ρ mapping of patellofemoral cartilage under in situ loading is demonstrated with prospective motion correction and T2 and T1ρ changes in response to loading are evaluated quantitatively, focusing on the load-bearing lateral patellar facet. T2 and T1ρ mapping were performed with equal spatial resolution and field of view for different loading conditions (0/20/40 kg). While no significant T2 differences for the three loading conditions were observed, T1ρ in superficial patellar cartilage was significantly reduced under loading. The quantitative findings suggest that T1ρ is a more reliable and sensitive marker for load-induced changes than T2. |
| 1541 | Correlation time mapping of articular cartilage degeneration in equine model | |
1Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland, 2Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland, 3Department of Applied Physics, University of Eestern Finland, Kuopio, Finland, 4Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland, 5Department of Equine Sciences, Utrecht University, Netherlands, 6Department of Orthopaedics, University Medical Center Utrecht, Netherlands, 7Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland |
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Correlation time mapping was utilized to study structural alterations in articular cartilage of the femoral trochlea harvested from skeletally mature equines. Samples originated from a study in which surgically created lesions in the lateral trochlear ridge of the femur were filled with different materials and were left to heal for 12 months. Correlation time maps of the cartilage or repaired tissues were obtained from fitting T1ρ relaxation dispersion data. The correlation times of the repair tissue from the lesion site and tissue next to the lesion site were significantly shorter than the correlation times in a location distant from the lesion, indicating gradual degenerative changes observed in early osteoarthritis. |
| 1542 | Multiparametric MRI assessment reveals early cartilage degeneration at 2 and 8 weeks after anterior cruciate ligament transection in a rabbit model | |
1Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland, 2Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland, 3Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, 4Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland, 5Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada, 6Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland |
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The sensitivity of several quantitative MRI parameters to early degenerative changes in articular cartilage was investigated in an experimentally induced anterior cruciate ligament transection (ACLT) rabbit model. Namely T1, continuous wave T1ρ (CWT1ρ), adiabatic T1ρ (AdT1ρ) and T2ρ (AdT2ρ), T2 and TRAFF (relaxation along a fictitious field) were measured at 9.4 T. All parameters showed significant elongation within two weeks of ACLT, except TRAFF. Rotating frame parameters showed some evidence of superior sensitivity to cartilage alterations. A multiparametric approach may enhance the discrimination power of quantitative MRI for early cartilage degeneration. |
| 1543 | T2-mapping evaluation of talar cartilage for chronic lateral ankle instability (LAI) with isolated anterior talofibular ligament (ATFL) tear, and combined ATFL and calcaneofibular ligament (CFL) tear | |
1Department of Radiology, Fudan University Affiliated Huashan Hospital, Shanghai, People's Republic of China, 2MR Collaboration NE Asia, Siemens Healthcare, Shanghai, People's Republic of China, 3Department of Sports Medicine, Fudan University Affiliated Huashan Hospital, Shanghai, People's Republic of China |
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The study aimed to use T2-mapping to quantitatively evaluate talus cartilage for chronic lateral ankle instability (LAI) with isolated anterior talofibular ligament (ATFL) tear, and combined ATFL and calcaneofibular ligament (CFL) tear. Seventeen patients with ATFL tear, 10 with ATFL+CFL tear, and 21 healthy subjects were recruited. All participants underwent T2-mapping scan, and patients completed American-Orthopedic-Foot-and-Ankle-Society (AOFAS) scoring. The results indicated that chronic LAI with ATFL+ CFL tear may result in much larger and more severe cartilage degeneration than isolated ATFL tear, and medial anterior of talus could be the main cartilage compartment affecting patients’ clinical symptom and prognosis. |
| 1544 | T1ρ acquired at higher Spin Lock Frequency and Composite R2 - R1ρ are better predictors of Patient-Reported Outcome in Osteoarthritis | |
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States |
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Synopsis: The agreement and associations of T1p values with different spin lock frequencies were evaluated for the detection of radiographic knee OA and association with patient-reported outcomes. Analyses were performed in vivo at 3T MRI. Significant differences were identified between FSL 500 Hz, 3 TSL and T2 in all knee compartments and between FSL 700 Hz, 3 TSL and FSL 500 Hz, 3 TSL. While similar behavior was observed in distinguishing radiographic OA, T1ρ computed at higher FLS (700 Hz) and R2-R1ρ 700Hz demonstrated a better association with patient-reported outcomes. |
| 1545 | Knee dGEMRIC at 7 T: Validation against 1.5 T and comparison of T1 mapping methods | |
1Dept. of Translational Medicine, Lund University, Malmö, Sweden, 2Dept. of Orthopedics, Skåne University Hospital, Lund, Sweden, 3Dept. of Medical Imaging and Physiology, Skåne University Hospital, Lund, Sweden |
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dGEMRIC (delayed Gadolinium Enhanced Magnetic Resonance Imaging of Cartilage) is a well-established technique for cartilage quality assessment in osteoarthritis at 1.5 T. The aim of this study was to establish dGEMRIC at 7 T by validation against 1.5 T and comparison of three T1 mapping methods: inversion recovery, variable flip angle and look locker. Both healthy volunteers and patients with early signs of osteoarthritis were scanned at both field strengths postcontrast. We conclude that dGEMRIC is feasible at 7 T and that inversion recovery is the preferred T1 mapping approach at 7 T. |
| 1546 | T1ρ assessment of cartilage in a large animal model of traumatic joint injury | |
1Radiology, University of Iowa, Iowa City, IA, United States, 2Orthopedics & Rehabilitation, University of Iowa, Iowa City, IA, United States |
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MRI offers the opportunity for early characterization of cartilage in injured joints with emerging contrast mechanisms such as T1ρ. The purpose of this work was to investigate the ability of T1ρ to detect early cartilage changes in a large animal (goat) model of PTOA. T1ρ imaging of injured joints showed increased relaxation times six months after injury compared to uninjured contralateral joints in five animals. T1ρ may help better elucidate the time course and mechanisms of cartilage degeneration in PTOA. |
| 1547 | Biomechanical T2-mapping in osteoarthritis with 3D-TESS at 7T MRI | |
1Department of Biomedical Imaging and Image-guided Therapy, High Field MR Centre, Medical University of Vienna, Vienna, Austria, 2Department of Orthopedic Surgery, Medical University of Vienna, Vienna, Austria, 3Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland, 4Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria |
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Biochemical MRI of hyaline cartilage shows promising results for the evaluation of OA. In this study we implemented in-vivo compression and a fast 3D-TESS sequence at 7T for cartilage transversal relaxation time (T2)-mapping of healthy volunteers and patients with risk factors for the development of early osteoarthritis of the knee (OA). Results show a location-dependent and differing behavior of T2-values under compression between the two groups, further increasing the value of T2-values as possible biomarker for OA. |
| 1548 | T2 -mapping and dGEMRIC of the patellar cartilage - long term follow-up after patellar stabilizing surgery in childhood | |
1Department of Women´s and Children´s Health, Karolinska Institutet, Stockholm, Sweden, 2Department of Diagnostic Radiology, Oulu University Hospital, Finland, 3Department of Paediatric Radiology, Karolinska University Hospital, Sweden, 4Department of Molecular Medicine and Surgery, Karolinska Institutet, Sweden, 5Stockholm Sports Trauma Research Center, Karolinska Institutet, Sweden, 6Department of Orthopedics, Lund University, Sweden |
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Recurrent patellar dislocation in childhood often require surgical stabilization, but the effects on cartilage quality after surgery is unknown. 17 patients were examined with T2 and dGEMRIC ≥5 years after surgery. dGEMRIC was shorter centrally, whereas T2 was longer most medially in the patellar cartilage of the operated patella (p<0.05). The short dGEMRIC indicates loss of glycosaminoglycans in the patella of the operated knee. Longer T2 may be an early sign of joint pathology. These findings may indicate an imbalance in the synthesis of matrix molecules, a sign of early cartilage degeneration. |
| 1549 | Cartilage T2 Relaxation Times in Both Knees of Healthy Individuals | |
1Human Biology, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, Stanford, CA, United States, 3Electrical Engineering, Stanford University, Stanford, CA, United States, 4Bioengineering, Stanford University, Stanford, CA, United States |
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The ACL-injured population is predisposed to developing radiographic Osteoarthritis post injury. Quantitative biomarkers such as T2 relaxation times evaluate the macromolecular composition of the cartilage matrix. Assessing the variation in this quantitative measure between knees of healthy individuals can help us identify degenerative difference brought on by injury. Using projection maps and pre-defined compartments, we measured the T2 relaxation times and quantified intrinsic differences between the knees of a group of healthy volunteers using coefficient of variation. This study demonstrates that there are similar T2 relaxation times for the left and right knees of healthy individuals. |
| 1550 | A prospective natural history study on cartilage composition changes in patients with low-grade cartilage injury | |
1Translational Medicine, Novartis Institutes for Biomedical Research, Basel, Switzerland, 2Biomedical Imaging and Image-guided therapy, Medical University of Vienna, Vienna, Austria, 3Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland, 4Institutes for Biomechanics, ETH, Zurich, Switzerland, 5Traumatology, Medical University of Vienna, Vienna, Austria |
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Changes in the macromolecular structure of articular cartilage were monitored in patients with a low-grade cartilage defect by using a comprehensive, compositional MRI approach over a period of 6 months. Preliminary results showed that, while no large change in glycosaminoglycan contents was observed, the bi-layer structure bound to the collagen fiber organization may have been further deteriorated over time. |
| 1551 | The Effect of Fat Saturation on Calculated T2 and T2* Relaxation Times in Articular Cartilage | |
1Mechanical Engineering, Stanford University, Stanford, CA, United States, 2Radiology, Stanford University, CA, United States |
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This study aimed at identifying differences in T2 and T2* relaxation times in knee cartilage with and without the use of fat suppression. Four volunteers were scanned with 3D cones, 2D multi-echo FSE, and qDESS sequences with and without fat sat. For cones and qDESS, T2* and T2 values increased with use of fat sat. For 2D FSE, values did not change. The results show that use of fat sat can have an effect on quantitative MRI parameters. |
| 1552 | Simulated reorientational correlation times of collagen-associated water | |
1Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland, 2Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland, 3Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, 4Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, 5Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland |
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Correlation times of molecular motions are fundamentally related to magnetic relaxation. We use molecular dynamics simulations to compute the reorientational correlation times of water molecules associated with a model collagen molecule. Our aim is to provide a reference independent of measurements of correlation times of water in articular cartilage. The results suggest that although the reorientation slows down close to the protein surface, the diffusion between the different water pools appears to render the average correlation times short as compared to a water molecule trapped close to the macromolecule. |
| 1553 | T1ρ and T2 of Articular Cartilage in the Thumb Carpometacarpal Joint | |
1Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY, United States |
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Radiography is commonly used to evaluate osteoarthritis at the thumb carpometacarpal (CMC) joint, but newer quantitative magnetic resonance imaging (MRI) techniques provide additional information regarding biochemical composition of trapezial (TM ) and 1st metacarpal (MC) articular cartilage. Morphologic MRI and quantitative T1ρ and T2 mapping of the thumb CMC joint was performed. T1ρ and T2 values of the TM and MC were similar, and full ligamentous tears were not found. This pilot study showed that quantitative T1ρ and T2 mapping is feasible at the human thumb CMC joint. |
| 1554 | 3D modeling of cartilage surfaces at the knee using clinical magnetic resonance imaging data | |
1Radiology, University of Cambridge, Cambridge, United Kingdom, 2Radiology, Royal National Orthopaedic Hospital, Stanmore, United Kingdom, 3Engineering, University of Cambridge, Cambridge, United Kingdom, 4Division of Trauma & Orthopaedic Surgery, University of Cambridge, Cambridge, United Kingdom |
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We present a surface-based method for analyzing articular cartilage at the knee using clinical MRI data. This method offers several advantages over existing approaches, including the ability to visualize the spatial distribution of cartilage thickness and compositional parameters, and perform surface-based comparisons between individuals and within individuals over time using statistical parametric mapping. We outline the steps involved in the analysis pipeline and describe initial results in 5 human cadavers and 2 human subjects in vivo, demonstrating the promise of this technique. |
| 1555 | Quantitative susceptibility mapping of articular cartilage at different orientations to investigate susceptibility anisotropy | |
1Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, 2Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland, 3Research Unit of Medical Imaging, Physics and Technology, University of Oulu, 4Department of Medical Physics & Biomedical Engineering, University College London |
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In this study we examined ex-vivo bovine articular cartilage using quantitative susceptibility mapping (QSM). Our purpose was to find a reliable QSM measurement and estimation protocol and then study how different enzymatic and chemical degradations affect the susceptibility of articular cartilage, in order to establish the feasibility of QSM for the assessment of articular cartilage. Treatments by trypsin (to degrade proteoglycans) and EDTA (to remove calcifications) were found to have minimal effects on the susceptibility. However, a significant depth-wise anisotropy of susceptibility in cartilage was observed. Further studies are warranted to investigate the susceptibility changes in cartilage. |
| 1556 | In Vivo Multicomponent T1ρ and T2 Relaxation Mapping of Human Knee Cartilage | |
1Radiology, New York University, School of Medicine, New York, NY, United States |
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In this study, we demonstrated the feasibility of in-vivo biexponential T1ρ and T2 relaxation measurement of knee articular cartilage using 3T MRI in clinically feasible scan times in eight healthy volunteers. Our preliminary results demonstrate that the biexponential model better represents the relaxation behavior in articular cartilage and can be used to distinguish different water compartments associated with macromolecules (tightly bound and loosely bound water) in the cartilage. |
| 1557 | Compressed Sensing Microscopic MRI in Articular Cartilage at 7T: Quantitative Determination of GAG Concentration using dGEMRIC Method | |
1Center for In Vivo Microscopy, Department of Radiology, Duke University, Durham, NC, United States, 2Physics and Center for Biomedical Research, Oakland University, Rochester, MI, United States |
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To evaluate the compressed sensing feasibility of quantification GAG concentration using dGEMRIC method, high resolution T1 mapping of articular cartilage was accelerated using various acceleration factors. It demonstrates that using CS doesn’t introduce major deviations in quantification of GAG concentration even with acceleration factor of 16, which holds great promise in making quantitative imaging techniques more accessible for clinical applications. |
| 1558 | Quantitative multiparametric relaxation time mapping of experimental model of osteoarthritis in the equine | |
1Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, 2Department of Diagnostic Radiology, Kuopio University Hospital, Kuopio, Finland, 3Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland, 4Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland, 5Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands, 6Department of Orthopaedics, University Medical Center Utrecht, Utrecht, Netherlands, 7Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland |
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In this study, sensitivity of several quantitative MRI (qMRI) parameters, namely T1, T2, continuous wave (CW) T1ρ, adiabatic T1ρ, adiabatic T2ρ and TRAFF were investigated for their sensitivity to secondary degenerative changes in equine articular cartilage specimens (n=13+6 lesions and controls, respectively) due to presence of surgically induced lesions in the adjacent tissue. Significant differences in relaxation times between ROIs in the secondary affected, lesion repair tissue and adjacent controls area or control animals were detected. The findings suggest that properties of cartilage are altered due to the presence of a lesion in adjacent tissue. |
| 1559 | Zonal differences of T1rho and T2 relaxation times of the meniscus: comparison study between normal and osteoarthritis knees | |
1Radiological Sciences, University of California Irvine, Orange, CA, United States, 2Orthopaedic Surgery, University of California Irvine, Orange, CA, United States |
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We compared the zonal differences of T1rho and T2 relaxation times of the meniscus in normal and osteoarthritis knees. Our study indicates that T1rho and T2 relaxation times in degenerative meniscus decrease and demonstrate more homogenous values throughout the meniscus. |
| 1560 | A Comparison of T2 Measurement Changes on MRI and Clinical Correlation in a Pilot Randomised Controlled Trial Comparing Meniscal Allograft Transplantation to Physiotherapy | |
1Orthopaedics, University Hospital Coventry and Warwickshire, Coventry, United Kingdom, 2Health Sciences, University of Warwick, Coventry, United Kingdom, 3Medical Physics, University Hospital Coventry and Warwickshire, 4University Hospital Coventry and Warwickshire, 5Orthopaedics, University Hospital Coventry and Warwickshire, 6Health Sciences, University of Warwick, 7Orthopaedics, University of Oxford |
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This pilot study shows the T2 changes that occur within cartilage in patients with meniscal transplantation. A full trial to prove whether meniscal allograph translation is justied |
| 1561 | Regionally Dependent T2* Values of the Patellar Tendon in Collegiate Basketball Players | |
1Deparment of Radiology and Imaging - MRI, Hospital for Special Surgery, New York, NY, United States |
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Patellar tendinosis is a significant debilitation in collegiate and professional athletes that frequently leads to reduced performance. The quantitative magnetic resonance imaging (MRI) technique of T2* mapping is well suited to evaluate patellar tendinosis. This study evaluated regional differences of T2* values in collegiate basketball players pre-season. Short and long T2* values were both prolonged proximally, and no correlations were found with corresponding morphologic imaging. Continued longitudinal imaging will permit the evaluation of the development of tendinosis or micro-tears. |
| 1562 | Spiral Fingerprinting of Articular Knee Cartilage and Bone | |
1Radiology, University of Cambridge, Cambridge, United Kingdom, 2IMAGO7 Research Center and IRCCS Stella Maris, Pisa, Italy, 3Radiology, University of Cambridge, 4GE Global Research, Munich, Germany |
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Magnetic resonance fingerprinting (MRF) seeks to acquire MRI parameter maps at shorter overall scan duration than achievable through separate image acquisitions. This work demonstrates multi-slice MRF at 3T for T1, T2, and proton-density mapping of a healthy human knee at a high in-plane spatial resolution (0.7x0.7mm$$$^2$$$) with an eight-channel transmit/receive coil at 3T. The spiral trajectories enabled quantification of tissues with ultrashort echo-times, such as trabecular bone. |
| Exhibition Hall | Monday 16:15 - 18:15 |
| 1563 | Quantitative Evaluation of T2 Signal Intensity for the Assessment of Muscle Denervation | |
1Radiology and Imaging, Hospital for Special Surgery, New York, NY, United States |
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Presence and severity of muscle denervation due to peripheral neuropathy are conventionally evaluated using needle electromyography (EMG); the results of which are critical in the diagnosis of nerve injury and prognosticating nerve recovery. Routine MRI can confirm the presence of denervation but is unable to quantify severity and relies on qualitative detection of diffuse T2-weighted signal hyperintensity of the muscle and fatty infiltration (if chronic). This pilot study explores the role of T2 mapping in the diagnosis denervation and for quantification of severity. T2 mapping may be an important complement to EMG results, particularly given the drawbacks associated with EMG. |
| 1564 | Noninvasive MRI Biomarkers for Muscular Dystrophy Progression in Young Muscle | |
1Radiology, University of Washington, Seattle, WA, United States, 2Biochemistry, University of Washington, Seattle, WA, United States, 3Neurology, University of Washington, Seattle, WA, United States, 4Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Washington, Seattle, WA, United States, 5Medicine, University of Washington, Seattle, WA, United States |
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Muscular dystrophy is a family of inherited diseases characterized by progressive muscle weakness that leads to muscle damage and wasting, and in the case of Duchenne muscular dystrophy (DMD), is fatal. Clinical measures of muscular dystrophy rely on surgical biopsy, which is invasive and provides a limited overview of the disease’s progression. Magnetic resonance imaging (MRI) may provide valuable information pertaining to tissue characteristics of this disease. We performed multi-parametric MRI to assess the changes in young dystrophic mice. The changes observed in skeletal muscles demonstrate MRI parameters may be used to track disease progression and future treatment options. |
| 1565 | Semi-automated analysis of diaphragmatic motion with cine MRI in controls and non-ambulant Duchenne Muscular Dystrophy (DMD) patients | |
1Imanova, London, United Kingdom, 2UCL, Institute of Child Health, London, United Kingdom, 3University College London, 4Imperial College London, United Kingdom, 5GlaxoSmithKline, Brentford, United Kingdom |
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This study presents both an analysis pipeline for measuring diaphragmatic motion from cine MRI data, and the application of this image processing technique to investigate exploratory MRI endpoints of respiratory function in both healthy controls and non-ambulant DMD boys. Cine-derived metrics of diaphragm motility and contractility correlated with sitting spirometry-derived forced vital capacity, and showed relationships with disease progression surrogates of age and months non-ambulatory, as well as a longitudinal change over 12 months. Longitudinal changes were not seen in spirometry measures. |
| 1566 | Potential of Stimulated Echo Diffusion-weighted Imaging as Disease Marker in Duchenne Muscular Dystrophy | |
1Radiology, LUMC, Leiden, Netherlands, 2Human Genetics, LUMC, Leiden, Netherlands, 3Institute of Child Health, University College London, London, United Kingdom, 4Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle, United Kingdom |
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We used stimulated echo diffusion weighted imaging (STE-DWI) in a mouse model of Duchenne muscular dystrophy (mdx). From the data in mdx or wild type animals we observe that although muscle fibre size is smaller in the mdx mouse, the diffusion data show increased diffusibility – opposite to the hypothesised effect if fibre size is the main determinant of restricted water diffusion. Muscle fibre permeability is significantly greater in the mdx mouse, suggesting that the overall system permeability has a countering effect on diffusion restriction. Additional modelling is required to capture these two opposing effects. |
| 1567 | Magnetic resonance biomarkers for cachexia in a mouse model of pancreatic ductal adenocarcinoma. | |
1Department of Radiology, University of Washington, Seattle, WA, United States, 2Center for Industrial and Medical Ultrasound Applied Physics Laboratory, University of Washington, Seattle, WA, United States, 3Department of Medicine, University of Washington, Seattle, WA, United States |
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Cancer induced cachexia is prevalent with many cancers and is characterized by loss of muscle and fat mass. In pancreatic cancer the syndrome affects approximately 80% of patients. Non-invasive multi-parametric MRI was used to monitor the progression of cachexia in a genetically engineered mouse model of pancreatic ductal adenocarcinoma (PDAC). Using pixel-by-pixel comparison, we demonstrate a significant decrease in skeletal muscle T2 and increase in magnetization transfer ratio (MTR). Additionally, we found significant difference in diffusion parameters. |
| 1568 | Fast delineation of calf muscles for quantitative MRI applications | |
1Consultants for Research in Imaging and Spectroscopy, Tournai, Belgium, 2Support Center for Advanced Neuroimaging, Institute for Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Switzerland, 3NMR Laboratory, Institute of Myology, Paris, France, 4CEA, DRF, I²BM, MIRCen, NMR Laboratory, Paris, France |
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One typical obstacle in quantitative MRI lies in the delineation of the regions of interest. When not absolutely necessary, per-muscle analyses are often abandoned, resulting in the loss of a wealth information. A software dedicated to accelerated segmentation of muscle images was recently introduced. It was tested here on the calf muscles of healthy volunteers and Duchenne patients. Results showed an important gain in average speed and were close to the manual segmentation used as reference. Thus, the tested software proved to be a valuable tool for quantitative analysis of skeletal muscle NMR images. |
| 1569 | Influence of muscle fiber tension on 31P MRS recovery parameter after intense exercise | |
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany |
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When performing exercise induced 31P MRS motion and activities from the everyday life and the positioning of the investigated extremities within the MR scanner should be considered, since this could induce partial ischemia effects like muscular cramps. The aim of this study was to prove the effect of muscle tension on metabolic parameter measured by 31P MRS after an intense exercise. PCr recovery as well as pH kinetic was significantly slowed by a partial ischemia preventing a quantitative evaluation. |
| 1570 | Multi-parametric characterization of highly fat infiltrated muscular dystrophy patients: results of a multi-variate analysis. | |
1Department of Information Engineering, University of Padova, Padova, Italy, 2Neuroimaging Lab, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini (LC), Italy, 3Functional Rehabilitation Unit, Neuromuscular Disorders, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini (LC), Italy, 4Radiology Department, University Medical Center Utrecht, Utrecht, Netherlands |
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Limb Girdle Muscular Dystrophies (LGMD) are a family of myopathies characterized by progressive degeneration and fat infiltration of muscular tissue. In the context of a study that includes Dixon, T2 quantification and diffusion MRI (dMRI), we investigated a multi-variate analysis to remove the effect of fat from concurrent measures and correlate them with clinical indexes of strength. In our dataset of highly infiltrated patients, T2 and dMRI metrics were strongly biased by fat. Our results show that it is possible to mitigate the bias by multi-variate modeling of the FF effect while retaining disease specific effects. |
| 1571 | Changes in muscle morphometry, composition and performance in patients with sporadic inclusion body myositis | |
1Novartis Institutes for Biomedical Research, Basel, Switzerland, 2VirtualScopics, LLC, Rochester, NY, United States, 3MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom, 4Novartis Pharmaceuticals Corporation, East Hanover, NJ, United States, 5Novartis Pharma AG, Basel, Switzerland |
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A comprehensive MRI approach was used to characterize changes in muscle structure and composition in patients with sporadic inclusion body myositis (sIBM) over 1-year. Results showed progressive deterioration in muscle quality, e.g. increased connective tissue volume in the most affected muscles, and this appeared to be associated with a functional impact. |
| 1572 | Correlating MRI and Histological Parameters in GRMD Muscles: A Comparison Between 3T and 4.7T Acquisitions | |
1Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, United States, 2Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, United States, 3Small Animal Imaging and Radiology, Texas A&M University, College Station, TX, United States, 4Department of Large Animal Clinical Sciences, Texas A&M University, College Station, TX, United States, 5Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States |
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The relationship between localized histological truth and various MRI quantitative measures were investigated using canine models. In this study, GRMD pectineus muscle samples were imaged on a 3T clinical scanner and a 4.7T small-bore scanner. Trichrome stained histology slice was registered to the 3D MRI volume. Localized quantitative MRI parameters are correlated with histology analysis (muscle, fibrosis and interstitial tissue percentage). Parameters derived from the 4.7T MRI data show consistent correlations, while those from 3T MRI data do not show consistent correlation. |
| 1573 | Targeted modulation of retinoid signaling using polymeric nanoparticles in a mouse model of Amyotrophic Lateral Sclerosis | |
1Neurobiology, Barrow Neurological Institute, Phoenix, AZ, United States, 2Research Imaging, Barrow Neurological Institute, Phoenix, AZ, United States |
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Retinoid signaling activity in the CNS, mediated by RARβ, directly influences ALS pathology development and progression in vivo and CNS targeted delivery of RARβ agonists can reduce ALS pathology in vivo when delivered systemically via polymeric nanoparticles. In this study the therapeutic affect of adapalene, a RARβ agonist, loaded nanoparticles were examined by measuring quadriceps volume in a SOD1G93A mouse model of ALS. |
| 1574 | Multicomponent 3D-T1ρ and T2 Relaxation Mapping of Skeletal Muscle: In-vivo Feasibility | |
1Radiology, New York University, School of Medicine, New York, NY, United States |
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In this study, we investigated the in-vivo feasibility of multicomponent 3D-T1ρ and T2 relaxation mapping in calf muscle using 3T MRI in clinically feasible scan times on eight healthy volunteers. Our preliminary results demonstrate that the biexponential model better characterized the relaxation behavior in calf muscle and can be used to differentiate between different water compartments associated with macromolecules (collagen and contractile proteins) and extracellular/vascular water in calf muscle. |
| 1575 | Fat fraction and muscular volume of entire supraspinatus muscle with/without tendon tear using IDEAL-IQ sequence | |
1Radiology, St.Luke's International Hospital, Tokyo, Japan, 2Department of Intelligent Image Information, Gifu University, 3St.Luke's International Hospital, 4Radiology, University of California, Irvine |
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Muscular atrophy and fatty degeneration of the supraspinatus muscle occurs after rotator cuff tear. It is often necessary to evaluate for these muscle abnormalities following tears to determine surgical candidacy. We usually evaluate this on a single slice. However, it is not well known whether this slice is representative of fatty degeneration and muscular atrophy overall. Furthermore, it is also not known how fatty degeneration and muscular atrophy will progress after tear. The purpose of this study was to make a standardized fat fraction and muscular volume model in patients with or without supraspinatus tendon tear using IDEAL-IQ sequence. |
| 1576 | Perturbed muscle mitochondrial function in Sarcopenia | |
1A*STAR-NUS Clinical Imaging Research Centre, Singapore, Singapore, 2Division of Paediatric Genetics and Metabolism, National University Hospital, 3National University of Singapore, 4A*STAR-NUS Clinical Imaging Research Centre |
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In this study we use 31P MRS in combination with Near Infra-red Spectroscopy to assess muscle mitochondrial function and changes in oxygenation in patients with Sarcopenia as to date, the etiology and molecular mechanisms of sarcopenia remain poorly understood. 10 males diagnosed with sarcopenia and 10 healthy controls were scanned where 31P MRS: A fully relaxed 31P MR spectrum data and exercise paradigm were acquired. MVC were significantly different between the sarcopenic and healthy groups (p=0.0044). Despite this, there was a tendency for increased ATP turnover in patients compared with healthy controls (44% and 66% MVC (ATP turnover p= 0.5642 44%MVC, p= 0.6128 66%MVC). Patients with sarcopenia showed significantly higher oxidative ATP synthesis ATP at 66%MVC where p= 0.0477. These results indicate that at least some of this increased requirement can be met oxidatively, with no contribution from breakdown of PCr at the end of exercise. |
| 1577 | Disease progression in skeletal muscles of Myotonic Dystrophy Type 1 evaluated using quantitative MRI | |
1Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, Netherlands, 2Neurology, Radboud university medical center, Nijmegen, Netherlands, 3Neuromuscular Reference Center, Henri Mondor university hospital, Paris, France |
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We studied the occurrence and progression of fatty infiltration, atrophy and edema-like processes in calf and thigh muscles of Myotonic Dystrophy Type 1 (DM1) patients. Fat fraction (FF) and muscle volume (MV) were obtained by a DIXON-sequence and T2 of muscle water (T2water) was calculated by a bi-component extended-phase-graph model. Calf and thigh muscles show fatty infiltration and increased T2water in non-fat infiltrated and fat infiltrated muscles. Atrophy is observed in four calf muscles and one thigh muscles. FF significantly increases in 10 months in fat infiltrated and non-fat infiltrated muscles, but MV only decreases in fat infiltrated thigh muscles. |
| 1578 | Body Composition Analysis Combined with Individual Muscle Measurements using Dixon-MRI | |
1Department of Medical and Health Sciences, Linköping University, Linköping, Sweden, 2Advanced MR Analytics AB, Linköping, Sweden, 3Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden, 4Department of Biomedical Engineering, Linköping University, Linköping, Sweden, 5Obstetrics and Gynecology, Linköping University, Linköping, Sweden |
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Body composition analysis is increasingly important for diagnosis and follow-up in many patient groups and medical conditions. The combined fat and muscle quantification on global and regional level is not commonly reported. In this study a Dixon-MRI based acquisition and body composition analysis was extended to quantify individual muscles. Test-retest reliability was established in a clinically relevant group of 36 postmenopausal women. This method enables advanced phenotyping combined with measurements of specific muscles to target clinical questions. |
| 1579 | A Potential Pathophysiological Link Between Generalized and Localized Muscle Fat Infiltration in Chronic Whiplash Patients | |
1Department of Biomedical Engineering, Linköping University, Linköping, Sweden, 2Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden, 3Department of Medical and Health Sciences, Physiotherapy, Linköping University, Linköping, Sweden, 4Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, 5Department of Medical and Health Sciences, Linköping University, Linköping, Sweden |
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Muscle fat infiltration (MFI) in the cervical multifidi muscles and whole-body skeletal muscle tissue was measured in participants with chronic whiplash associated disorders (WAD) using whole-body fat-water separated MRI to investigate potential interaction between deep neck muscle and generalized MFI. Thirty participants with chronic WAD and 30 matched controls were included. MFI in multifidi was strongly associated to whole-body MFI as well as to severity of WAD. The strong association between Multifidi MFI and whole-body MFI indicates that both generalized factors and localized effects related to the trauma may be important for understanding the pathophysiology of chronic WAD. |
| 1580 | Whole-body MRI in facioscapulohumeral muscular dystrophy: Preliminary results | |
1Center for Genetic Muscle Disorders, Kennedy Krieger Institute, Baltimore, MD, United States, 2Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Siemens Healthcare, Baltimore, MD, United States, 4Radiology and Imaging, Hospital for Special Surgery, New York, NY, United States, 5Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 6Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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Facioscapulohumeral muscular dystrophy (FSHD) is a hereditary disorder that causes progressive muscle wasting. Whole-body MRI (WBMRI) was used to scan 24 adults with genetically-confirmed type 1 FSHD. Muscles were scored for fat infiltration and edema-like changes. Fat infiltration scores were compared to muscle strength and function measurements. Our analysis reveals a distinctive pattern of muscle involvement and sparing in FSHD. Averaged fat infiltration scores for muscle groups in the legs were statistically significantly associated with quantitative muscle strength and 10-meter walk time. We conclude that WBMRI offers a promising disease biomarker in FSHD and other muscular dystrophies. |
| 1581 | DTI imaging application of vastus medialis oblique muscle in recurrent patellar dislocation | |
1Radiology Department of Peking University Third Hospital, Beijing, People's Republic of China, 2Radiology Department of Tsinghua Changgung Hospital, Beijing, People's Republic of China, 3GE Healthcare, MR Research China, Beijing, People's Republic of China |
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The osseous-related factors that influence patellofemoral joint instability have been well-studied in plenty of the previous reported literatures. However, the muscle-related factors that affect patellofemoral joint instability have not been fully revealed. MRI is a noninvasive imaging method, including conventional MRI scans and diffusion tensor imaging (DTI) sequence, which can respectively reflect the macroscopic and microscopic structures of the muscle fibers.1,2 In the current study, the cross-sectional area were measure with DTI parameters of FA, ADC, and λ1, λ2, λ3 of vastus medialis oblique (VMO). Thereafter, these parameters were compared between the recurrent patellar dislocation patients and the healthy volunteers. |
| 1582 | Diffusion Tensor imaging in the Injuries of the Levator Ani Muscle in Female Pelvic Floor Dysfunction | |
1Radiology Department of Peking University Third Hospital, Beijing, People's Republic of China, 2GE Healthcare, MR Research China, BeiJing, People's Republic of China |
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To find the most vulnerable component of levator muscle, this research compared the levator ani muscle which contains pubovisceral, puborectal and iliococcygeal muscles between the control group and the patient group by using DTI. 49 female PFD (pelvic floor dysfunction) patients and 51 female healthy subjects underwent DTI imaging on a 3.0T MR system. A significant difference was found in the FA value of the right pubovisceral muscle between the two groups, and therefore, this part are more likely to be damaged comparing with other compartments of levator ani muscle. DTI with fiber tractography permits the evaluation of the injuries of levator ani muscle, which has a certain effect in revealing the pathogenesis of the female pelvic floor dysfunction. |
| 1583 | Analysis of T2 Relaxation Times in Vastus Lateralis Muscle after Anterior Cruciate Ligament Injury | |
1College of Engineering, Department of Biomedical Engineering, Lexington, KY, United States, 2Department of Radiology, College of Medicine, Lexington, KY, United States, 3Magnetic Resonance Imaging and Spectroscopy Center, Lexington, KY, United States, 4Department of Neuroscience, College of Medicine, 5Department of Rehabilitation, College of Health Sciences, Lexington, KY, United States |
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Anterior cruciate ligament (ACL) injuries are associated with a persistent decrease in quadriceps muscle strength despite rehabilitation. Previous studies have shown that ACL injury results in muscle disorganization, which could account for the loss in strength. We sought to use dual-spin echo and multi-spin echo sequences to estimate T2 of the vastus lateralis in injured and uninjured limbs of twenty-two ACL injured subjects. T2 of the injured limb was significantly longer than the uninjured limb for both pulse sequences. Our results suggest that T2 relaxation may provide clinicians a means to quantitatively monitor muscle recovery after ACL injury. |
| 1584 | Optimal excitation location for magnetic resonance elastography of the supraspinatus muscle | |
1Department of Radiological Science, Graduate School of Human Health Science, Tokyo Metropolitan Unversity, Arakawa, Japan, 2Health Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan, 3Department of Mechanical Engineering, Tokyo Denki University, Adachi, Japan, 4Department of Judo Neurophysiotherapy, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan, 5Department of System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan |
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It is difficult to palpate the supraspinatus muscle since it is difficult to determine their anatomic location superficially. Magnetic resonance elastography (MRE) can measure tissue stiffness quantitatively only if vibrations reach these tissues. To vibrate the tissues efficiently, it is necessary to determine the best excitation location. We investigated the excitation location suitable for MRE of the supraspinatus muscle. When the excitation location was placed on the trapezius muscle, the wave images represented clear wave propagation compared with those on the head of humerus. Therefore, optimal excitation location may be the trapezius muscle in the MRE of the supraspinatus muscle. |
| 1585 | Simultaneous measurement of muscle transverse relaxation rates of R2, R2' and R2*: application in unilateral femoral artery embolization | |
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, People's Republic of China, 2College of Engineering, Peking University, Beijing, People's Republic of China, 3interventional radiology and vascular surgery, Peking University First Hospital, Beijing, People's Republic of China, 4Department of Radiology, Peking University First Hospital, Beijing, People's Republic of China |
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Diagnosis of the ischemic lesion is challenging and often requires the use of pharmaco-mechanical methods. This study demonstrates the feasibility of using a susceptibility-based MRI technique with the multi-echo gradient and spin echo (MEGSE) sequence to assess the skeletal muscle oxygenation alternations in animal model of unilateral femoral artery embolization. The results shown that the skeletal muscle R2 decreases obviously from after femoral artery embolization, while R2’ increases correspondingly. MEGSE seems to be an appropriate method for the evaluation of skeletal muscle ischemia after embolization. |
| 1586 | Feasibility of Quantifying Bone Metabolism in the Femoral Neck in Human Subjects using Multi-Modality Imaging | |
1University of Pennsylvania, Philadelphia, PA, United States |
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18F-sodium fluoride (NaF) is a readily available radiotracer that has shown great potential to study bone metabolism associated with osseous diseases such as osteoporosis. We analyzed PET/CT and MRI data to study the effects of bone volume fraction and marrow distribution on the uptake of NaF in the proximal femur. Our data showed that the mean standardized uptake (SUVmean) decreased with age and became more significant when local adjustments for bone and bone marrow were taken into account. We foresee the importance of high-resolution microstructural bone MRI for the partial volume correction of PET data for accurate quantification bone metabolism. |
| 1587 | Segmentation of CMF Bones from MRI with A Cascade Deep Learning Framework | |
1Department of Radiology and BRIC, UNC-Chapel Hill, USA, Chapel Hill, NC, United States, 2Houston Methodist Hospital, Houston, TX, USA |
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Accurate segmentation of CMF bones from MRI is one of the most important fundamental steps in clinical applications, and it can also be used in other areas, such as character animation and assistive robotics. In this paper, we propose a cascade framework based on the recently well-received and prominent deep learning methods. Specifically, we first propose a 3D fully convolutional network architecture for a coarse segmentation of the bone tissue. Further, we propose to utilize CNN for fine-grained level segmentation around the predicted bone tissue area. The conducted experiments show that our proposed 3D deep learning model could achieve good performance in terms of segmentation accuracy. |
| 1588 | Robust Pore Water Suppression in Cortical Bone with Multiple Adiabatic Inversion Recovery | |
1Vanderbilt University, Nashville, TN, United States |
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Measurement of bound water concentration in cortical bone with MRI is a promising method for evaluating bone fracture risk. One approach to measure bound water involves suppression of pore water signal with an adiabatic inversion-recovery pulse sequence. However, this approach requires a priori knowledge of pore water T1 which itself is expected to vary with bone porosity. We propose to minimize the effect of subject-dependent pore water T1 variation by in bound water imaging using a multiple adiabatic inversion recovery preparation optimized to suppress pore water over a broad T1 domain. |
| 1589 | MRI Assessment of the Effect of Low-Magnitude Mechanical Stimulation on Postmenopausal Bone Loss | |
1University of Pennsylvania, Philadelphia, PA, United States |
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Low-magnitude mechanical stimulation (LMMS) has shown great potential as a non-pharmacological intervention for improving bone quality in animal models. However, human trials have yielded less compelling evidence, possibly related to difficulties in maintaining adherence and use of conventional imaging techniques not being able to detect subtle longitudinal changes. Here we investigated the use of high-resolution structural bone MRI in monitoring treatment efficacy of LMMS in postmenopausal women. The data show that baseline bone volume fraction at the distal tibia is associated with the changes observed over one year of active LMMS or placebo treatment. |
| 1590 | Potential of High Resolution Isotropic Microstructural MRI of the Proximal Femur | |
1University of Pennsylvania, Philadelphia, PA, United States, 2University of Pennsylvania, 3New York University |
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Microstructural MRI based finite element modelling is an area of current research in regards to the role that this technology can play as an efficient and affordable metric for quantifying bone integrity and for identifying fracture risk. This study was conducted in an attempt to unveil the extent to which MRI resolution impacts the quantitative output generated by finite element models pertaining to the parameter of bone stiffness of the proximal femur in vitro. Conclusions reveal a statistically significant variance relative to the values generated for two differing MRI resolution classes. |
| 1591 | Simplified approach to quantification for hand synovitis in rheumatoid arthritis using dynamic contrast enhanced MRI: pixel-by-pixel time intensity curve shape analysis | |
1Graduate School of Health Sciences, Hokkaido University, Sapporo, Japan, 2Faculty of Health Sciences, Hokkaido University, Sapporo, Japan, 3National Sale Division, CT Sales Department, Application Group, Toshiba Medical Systems Corporation, Tochigi, Japan, 4Internal Medicine 2, Hokkaido University Hospital, Sapporo, Japan, 5Yaesu Clinic, Tokyo, Japan |
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Quantification for synovitis using time intensity curve (TIC) shape analysis of rheumatoid arthritis has been believed to require long acquisition time up to 6-7 minutes to observe washout phase. In this study, we found that wash out phase does not contribute to accurate depiction of synovitis in the hand and simplified TIC shape analysis could significantly decrease acquisition time from about 6 minutes to 3 minutes. |
| 1592 | A novel approach to measure tibial component migration by low field markerless magnetic resonance imaging | |
1Centre for Orthopaedic Surgery OCON., Hengelo, Netherlands, 2University of Twente, Faculty of Science and technology, Enschede, Netherlands |
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This study evaluated if low field MRI is a practical alternative for Roentgen stereophotogrammetric-analysis (RSA) to measure prosthetic migration. This also included determining the optimal registration method for this purpose. The detection of migration on low field MRI was sufficient for clinical use in two of the translation directions and all three rotational directions. Manual registration proved to be the most accurate method for markerless MRI (MMRI) estimation of the migration. |
| 1593 | Quantitative Mapping of the Ischemic Femoral Head in a Piglet Model of Legg-Calve-Perthes Disease | |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Veterinary Population Medicine, University of Minnesota, St. Paul, MN, United States, 3Texas Scottish Rite Hospital, Dallas, TX, United States, 4Orthopaedic Surgery, UT Southwestern, Dallas, TX, United States, 5Radiology, University of Minnesota, Minneapolis, MN, United States |
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This study investigated the sensitivities of T1, T2, continuous-wave T1ρ, adiabatic T1ρ, and RAFF relaxation times to ischemia-induced necrosis and subsequent repair of the developing femoral head in a piglet model of Legg-Calve-Perthes disease (LCPD), a disabling childhood hip disorder. Quantitative maps of ischemic and control femoral heads acquired ex vivo at 9.4T MRI were compared numerically and validated with histology. Our findings reveal that the relaxation times provide complementary information on the status of the pathological hip, which can potentially address a clinical need for diagnostic imaging tools to assess the early stages of LCPD. |
| 1594 | Age estimation using MR imaging of the third molar teeth and the medial clavicular epiphysis: Validation of a multifactorial approach | |
1Ludwig Boltzmann Institute Clinical Forensic Imaging, Graz, Austria, 2BioTechMed, Graz, Austria, 3University Center of Legal Medicine Lausanne-Geneva, University Hospital of Lausanne, Switzerland, 4Institute of Medical Engineering, Graz University of Technology, Austria, 5Institute of Forensic Medicine, Medical University of Graz, Austria, 6Institute for Computer Graphics and Vision, Graz University of Technology, Austria, 7Institute of Forensic Medicine, University of Basel - Health Department Basel, Switzerland |
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High migration rates in the last years put forensic age estimation of living people at the forefront of forensic research. The established standard for age estimation uses images acquired with ionizing radiation, therefore radiation-free alternatives such as MRI are currently of high interest. In this study a CT based multifactorial approach that combines wisdom teeth and clavicles was validated with MRI data. The sensitivity to estimate subjects under 18 years of age as minors with MRI lies above 93%. Our results showed that MR could replace the CT based multifactorial Approach. |
| 1595 | Three-dimensional fracture visualization with Zero Echo Time MRI | |
1GE Healthcare, Cambridge, United Kingdom, 2University Hospital of Zurich, Zurich, Switzerland |
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The present study is aimed at assessing the performance of proton density-weighted zero-echo time (ZTE) acquisition for the visualization of bone fractures. |
| 1596 | An Efficacy Analysis of Whole-Body Magnetic Resonance Imaging in the Diagnosis and Follow-Up of Polymyositis and Dermatomyositis | |
1China-Japan Friendship Hospital, Beijing, People's Republic of China, 2Philips Healthcare (China) |
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To evaluate the value of whole-body magnetic resonance imaging (WBMRI) in diagnosing muscular and extramuscular lesions in patients with polymyositis (PM) and dermatomyositis (DM). A retrospective analysis of WBMRI data was performed on PM / DM patients who met the Bohan and Peter diagnostic criteria. WBMRI comprehensively displays the muscular involvement in PM / DM patients, and has the ability to diagnose other associated extramuscular diseases, such as ILD and systemic malignancy. WBMRI can also help screen for multifocal steroid-induced osteonecrosis. |
| Exhibition Hall | Monday 16:15 - 18:15 |
| 1597 | Deformable Registration of In Vivo Human Spine Magnetic Resonance Imaging Using Scale Invariant Feature Transform (SIFT) Algorithm | |
1Brain and Mind Centre, University of Sydney, Sydney, Australia, 2Department of Radiological Science, Yonsei University, Wonju, Korea, Republic of, 3Ewha Brain Institute, Ewha Womans University, Seoul, Korea, Republic of, 4Department of Biomedical Engineering, The Catholic University of Korea College of Medicine, Seoul, Korea, Republic of, 5Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul, Korea, Republic of |
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Deformable registration process for in vivo human spine MR images can provide the crucial information to investigate the diagnostic performance and treatment effects of pathologies. Here, based on the scale invariant feature transform (SIFT) algorithm, we attempted to evaluate the deformable registration process for spine images, and compared with commercially mounted algorithm in MRI system. The results qualitatively and quantitatively showed fine results, and clearly showed the reproducibility of the use of SIFT algorithm compared with commercially mounted stitching algorithm on MRI system. Our approach can be helpful for the extension of other medical imaging modalities for image deformable registration. |
| 1598 | Perfusion and Fat Content of Lumbar Vertebral Body: Global and Regional Analysis | |
1Department of Nuclear Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan, 2Program of Electrical and Communications Engineering, Feng Chia University, Taichung, Taiwan, 3Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan, 4Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, 5Department of Radiology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan, 6Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taiwan |
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Vertebral blood perfusion has been reported that there was a decrease trend in normal aging people and post-menopause women and those with arteriosclerosis, fat marrow increased and osteoporosis. Although DCE-MRI and MRS have shown potential probing bone marrow content and blood perfusion characteristics of vertebra body in previous studies, all of these were ROI analysis only and lack regional information for bone marrow content and blood perfusion. Therefore, The purposes of this study were to investigate the regional perfusion and bone marrow content in vertebra body with use of DCE-MRI and six-point Dixon IDEAL technique by pixel-by-pixel analysis. |
| 1599 | Non-Gaussian water diffusion kurtosis imaging and T2* mapping of Intervertebral Disc Degeneration at 3T MR | |
1Radiology, Renmin Hospital of Wuhan University, Wuhan, People's Republic of China, 2GE healthcare China |
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To assess the feasibility of detecting early biochemical changes of nucleus pulposus (NP) in intervertebral disk degeneration (IVDD) by diffusion kurtosis imaging (DKI), and compare mean kurtosis (MK) and T2* mapping in IVDD according to Pfirrmann grades. Twenty individuals underwent lumbar sagittal T2-weighted image, DKI and T2* mapping. DKI related parameters—mean kurtosis (MK) and T2* values were measured. The differences between MK and T2* value in NP were highly significant. Pfirrmann grades were inversely significantly correlated with T2* values in the NP, and positively correlated with MK values, especially between Pfirrmann grade II ,III and Ⅳ. |
| 1600 | Bone marrow iron assessment using quantitative susceptibility mapping in iron overload rabbit model | |
1Department of Radiology, Seoul St.Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea, Republic of |
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The aim of our study was to assess the feasibility of quantitative susceptibility mapping (QSM) as a tool to quantify bone marrow iron level non-invasively. Nine rabbits were scanned before and after iron accumulations, and bone marrow susceptibility values of these rabbits were evaluated from the reconstructed QSM images. The results showed a linear correlation between the measured susceptibility changes and the injected iron doses. |
| 1601 | Quantitative study of longitudinal distribution of fat fraction in the lumbar spine | |
1Peking University Third Hospital, Beijing, People's Republic of China, 2GE Healthcare, MR Research China, People's Republic of China |
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The aim of this study was to explore the fat fraction(FF) variation of inter and intra vertebral bodies in the lumbar spine, by using water-fat imaging. In lumbar spine, L1 and L2 vertebras demonstrated lower FF level but with more common ‘margin higher’ FF distribution pattern comparing to other vertebras, which might be related to stress and activities of the vertebra. We suggested that FF distribution pattern indicate certain skeletal remodeling that affects bone strength, which may be a promising indicator in assessing prevalent fracture besides the increased average FF of the whole vertebral body. |
| 1602 | Intervertebral disc heterogeneity decoded with MRI histogram analysis | |
1Dept. of Medical Physics and Techniques, Sahlgrenska University Hospital, Gothenburg, Sweden, Sahlgrenska University Hospital, Gothenburg, Sweden, 2Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden, 3Dept of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden, 4Dept of Orthopaedics, Sahlgrenska University Hospital, Gothenburg, Sweden |
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Low back pain has major consequences for both the individual as well as for the society which often results in sick leave from work. Unfortunately, health care today lacks diagnostic techniques and procedures necessary to select and treat patients who would most benefit from treatment. Histogram analysis based on MRI imaging has the potential to display disc heterogeneity and possibly depict painful discs. A total of 98 histograms of 49 intervertebral discs were generated based on three mid-sagittal slices of high quality T2W MRI images and T2-maps. Using MATLAB, a two component Gaussian mixture distribution model was fitted to the histogram data in order to retrieve disc heterogeneity measures. Mann-Whitney U-test displayed a significant difference in disc heterogeneity measures with increased Pfirrmann grade. |
| 1603 | Synthetic contrast optimization of bone metastases | |
1SyntheticMR, Linköping, Sweden, 2Center for Medical Image Science and Visualization (CMIV), Linköping University Hospital, Linköping, Sweden |
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To achieve optimal contrast when imaging bone metastases, the patient would have to imaged multiple times at various contrast settings. This is not possible in practice, resulting in the use of standard contrasts that are often sub-optimal due to patient-specific variations in both healthy and metastatic tissue. Using synthetic MRI, it is possible to synthesize a multitude of contrasts from a single scan. This makes it possible to determine optimal contrast weighing post-scan. Studying bone metastases, synthetic images where used to develop a mathematical model of perceived contrast, taking both tissue properties and the human visual system into account. |
| 1604 | The presence of newly defined classical features of intraneural perineurioma may obviate the need for fascicular biopsy and pathologic diagnosis | |
1Neurosurgery, Mayo Clinic, Rochester, MN, United States, 2Radiology, Mayo Clinic, Rochester, MN, United States, 3Radiology, Mayo Clinic, 4Neurosurgery, Mayo Clinic, Rochester, MN, 5Radiology, Mayo Clinic, Rochester, MN |
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Intraneural perineurioma is typically diagnosed by targeted fascicular biopsy and histopathologic analysis. Through review of clinical history and magnetic resonance imaging of consecutive patients undergoing fascicular biopsy, we define the classical features of intraneural perineurioma as no cancer history, unifocal disease, moderate-severe T2 hyperintensity, moderate-severe contrast enhancement, homogeneous contrast enhancement, fusiform shape, and enlargement of involved nerves. This combination of features has a high specificity and moderate sensitivity for the diagnosis of perineurioma. When the classical features of perineurioma defined in this study are present, the high specificity of this combination of features may obviate the need for fascicular biopsy. |
| 1605 | The value of dynamic contrast-enhanced MRI quantitative parameters in evaluating the efficacy of neoadjuvant chemotherapy for osteosarcoma | |
1Department of Radiology, The Third Affiliated Hospital of Kunming Medical University, KunMing, Yunnan Province, People's Republic of China, 2The Third Affiliated Hospital of Kunming Medical University, 3GE healthcare, china, KunMing, Yunnan Province, People's Republic of China |
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Osteosarcoma is the most common bone sarcoma in children and adolescents 1. Response of osteosarcoma to NAC should be assessed preoperatively, but conventional imaging has limit, and histopathological examination cannot dynamically observe the response of tumor to treatment. DCE-MRI can reflect the pathophysiology of tumor at microvascular and cellular level. Currently, researchers have used DCE-MRI qualitative and semi-quantitative method to analyze the response of osteosarcoma to NAC, but studies on DCE-MRI quantitative analysis are rarely reported. Therefore, we analyzed the quantitative parameter change of DCE-MRI in 17 patients of osteosarcoma before and after NAC, and compared good response and poor response to chemotherapy in order to explore the value of DCE-MRI quantitative parameters in assessing the response of osteosarcoma to NAC. |
| 1606 | Fat Fraction Histogram Analysis: Insights into the Biology of Lipomatous Tumors | |
1Department of Radiation Sciences, Umeå University, Umeå, Sweden, 2Department of Radiology, Uppsala, Sweden, 3Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden, 4Department of Oncology and Pathology, Karolinska Institute and Karolinska University Hospital, Solna, Sweden, 5Department of Orthopaedic Surgery, Karolinska University Hospital, Solna, Sweden, 6Department of Medical Radiation Physics, Karolinska University Hospital, Stockholm, Sweden, 7Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden |
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Fat content evaluation in soft-tissue tumors is based on visual grading of T1-weighted images with uncertain accuracy and inter-rater variability. We used a multi-point Dixon technique to quantitatively measure the distribution of proton density fat fraction in different lipomatous tumors. The effect of radiotherapy on fat content in a myxoid liposarcoma was also assessed, with histograms revealing a distinct alteration. Our data give supporting evidence that maturation of tumor cells is the cause for the lipoma-like areas seen after radiotherapy of myxoid liposarcomas. On a voxel level (2×2×2 mm3) various lipomatous tumors exhibited different fat fraction histograms. |
| 1607 | Characterization of Through-Plane and In-Plane Artifacts using a 3D-Printed Grid Phantom with an Embedded Metal Hip Implant | |
1Robarts Research Institute, London, ON, Canada, 2Department of Medical Biophysics, University of Western Ontario, London, ON, Canada, 3Department of Surgery, University of Western Ontario, London, ON, Canada |
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Metal Artifact Reduction (MAR) is required for orthopedic imaging near implants. Novel MAR techniques have been developed in the past decade, creating a need for quantitative evaluation of the effectiveness of geometric distortion correction. We have developed a 3D-printed modular conformal grid phantom, consisting of a grid of regularly spaced spherical markers. This phantom provides a measure of inherent field inhomogeneity, and contains a conformal cavity in which a metal object can be embedded. This approach provides a means to characterize through-plane and in-plane artifacts across a 3D volume, facilitating testing and validation of novel MAR techniques during development. |
| 1608 | Cartesian UTE with echo time below 0.5 millisecond | |
1Institute for Biomedical Engineering, ETH, Zurich, Switzerland |
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MRI with sub-millisecond TE typically uses non-Cartesian sampling strategies such as radial UTE leading to increased sensitivity to eddy currents and a high computational burden. We report that TE values in the range so far reserved for radial UTE can be reached with Cartesian sampling using a gradient coil dedicated for muscoskeletal applications in humans. |
| 1609 | Iterative Denoising of Undersampled PROPELLER Diffusion-Weighted Imaging near Metal Implants | |
1Medical College Wisconsin, Milwaukee, WI, United States, 2GE Healthcare |
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Diffusion weighted imaging is widely used in musculoskeletal MR imaging. Current implementations of diffusion-weighted imaging include the use of PROPELLER DUO imaging sequence and multi-spectral MRI imaging techniques. However, these implementations are restricted by long acquisition times. In this work we propose to an approach to undersample the blades in a uniform fashion and denoise the reconstructed image using total variation based denoising approach. This approach provides acceptable results up to an acceleration factor of 3 and reduces the scan time. This reduction in scan time can be used to acquire multiple slices within clinically feasible scan times. |
| 1610 | Ultrashort Echo Time Chemical Shift Quantitative Susceptibility Mapping (UTE-CS-QSM) for Hemosiderin Assessment in Hemophilic Arthropathy | |
1Department of Radiology, University of California, San Diego, CA, United States, 2Institute of Electrical Engineering, Chinese Academy of Science, Beijing, People's Republic of China, 3Department of Medicine, Division of Hematology/Oncology, University of California, San Diego, CA, United States, 4Department of Radiology, Weill Cornell Medical College, New York, NY, United States, 5Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States |
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Hemosiderin deposition in hypertrophic synovium is a hallmark of progressive hemophilic arthropathy and accumulates with joint bleeding. . Conventional quantification of hemosiderin uses semi-quantitative MRI scores, assigning grades of small, moderate, or large to assess the burden of hemosiderin. To date, there is no known method to assess or quantify hemosiderin concentration within synovium due to the extremely short T2 values of this tissue. In this pilot study, we demonstrated that the clinically compatible IDEAL UTE-CS-QSM technique can be used to quantify hemosiderin depositions. We have shown that synovium in joints with hemophilic arthropathy demonstrates various susceptibility values, likely corresponding to different concentrations of hemosiderin. |
| 1611 | Chemical Shift T1 Quantification with Three-dimensional Ultrashort Echo Time Cones Imaging and IDEAL (3D UTE-Cones-IDEAL) Processing | |
1Department of Radiology, University of California, San Diego, CA, United States, 2Institute of Electrical Engineering, Chinese Academy of Science, Beijing, People's Republic of China, 3GE Healthcare, San Diego, CA, United States, 4Radiology Service, VA San Diego Healthcare System, San Diego, CA, United States |
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Conventional T1 measurements are subject to errors due to fat contamination and invisibility of the short T2 components. In this study, we aimed to develop 3D UTE with Cones sampling and IDEAL processing (3D UTE-Cones-IDEAL) with variable TRs for robust fat/water separation and more accurate T1 estimation of joint tissues ex vivo and in vivo. The results show that this technique can robustly separate water and fat signal and lead to longer T1s for water-rich tissues (such as muscle, tendon and peripheral nerve), and shorter T1s for fat-rich tissues. |
| 1612 | On the Source of MRI Off-Resonance Observables in Arthroplasty-Induced Metallosis | |
1Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 2MRI Division, Hospital for Special Surgery, New York, NY, United States, 3Anatomic Pathology and Orthopaedic Surgery, Cleveland Clinic, Cleveland, OH, United States |
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The deposition of metal particles near total joint replacements has substantial impact on patient morbidity. Current standards of clinical management of patients with symptomatic total hip replacements are highly leveraged on the presence of wear debris in periprosthetic tissues. Our group has recently developed methods to perform off-resonance based identification of metal particle deposits. Here, we provide analysis on the source of tissue-based metal particle Larmor frequency offsets. The results of this analysis provide new insight on the role of off-resonance observables in the progression of symptomatic failed total hip replacements. |
| 1613 | Fat Fraction and R2* as Measures of Bone Marrow Composition and Structure: Validation in Fat-Water-Bone Phantoms | |
1Centre for Medical Imaging, University College London, London, United Kingdom, 2Centre for Adolescent Rheumatology, University College London, London, United Kingdom, 3Medical Physics, University College London Hospitals |
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MRI is becoming central to clinical decision-making in diseases involving the bone marrow, including spondyloarthritis and multiple myeloma. Both diseases cause alterations in marrow composition and structure, but there is currently no reliable method for quantifying these changes. Here, we describe a series of fat-water-bone phantoms enabling validation of proton density fat-fraction (PDFF) and R2* as measures of marrow composition and trabecular bone mineral density (BMD) respectively. Our data suggest that PDFF measurements can be achieved with excellent accuracy. Furthermore, there was a strong relationship between R2* and BMD, suggesting that R2* could be used to monitor BMD in vivo. |
| 1614 | Simultaneous Quantification of Fat Fraction and R2* as measures of Bone Oedema/Adiposity and Structure in Spondyloarthritis | |
1Centre for Medical Imaging, University College London, London, United Kingdom, 2Medical Physics, University College London Hospitals, 3Centre for Adolescent Rheumatology, University College London |
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Treatment decisions in patients with spondyloarthritis increasingly involve the use of MRI to assess the extent, severity and type of inflammation surrounding the joints. However, conventional spin echo imaging requires subjective interpretation and gives little information about trabecular structure, despite the fact that new bone formation and bone destruction may both occur in spondylorthritis. Here, we describe the use of chemical shift-encoded MRI as a quantitative method for assessing inflammation of the sacroiliac joints. Specifically, we demonstrate the use of proton-density fat fraction and R2* as measures of bone marrow composition and structure, respectively, in both active and chronic inflammation. |
| 1615 | Application of lower extremity oxygenation imaging in animal model of microsphere-induced femoral artery embolization | |
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, People's Republic of China, 2interventional radiology and vascular surgery, Peking University First Hospital, Beijing, People's Republic of China, 3College of Engineering, Peking University, Beijing, People's Republic of China, 4Department of Radiology, Peking University First Hospital, Beijing, People's Republic of China |
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Embolization following percutaneous intervention is a universal problem occurring in all vascular beds, especially in lower extremities. This study assesses the performance of a noninvasive MRI based oxygenation imaging, in characterizing muscle oxygen extraction fraction (OEF) level after microsphere-induced lower extremity embolization in animal models. By comparison of the calculated muscle OEFs and R2’ before and after surgery, significantly increase could be found. The results show promise in the evaluation of early muscle ischemia in many clinical diseases such as acute lower limb embolism or peripheral artery disease. |
| 1616 | Age estimation of soft tissue hematomas using 3.0 T MRI: A feasible approach | |
1Institute of Forensic Medicine, Medical University of Graz, Graz, Austria, 2Ludwig Boltzmann Institute Clinical Forensic Imaging, Graz, Austria, 3Division of Neuroradiology, Vascular and Interventional Radiology, Department of Radiology, Medical University of Graz, Graz, Austria, 4Institute of Medical Engineering, Graz University of Technology, Graz, Austria, 5Institute of Forensic Medicine, University of Basel - Health Department Basel, Basel, Switzerland |
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Forensic imaging requires reliable analysis of hematomas and their resolution as they can have significant medico-legal consequences. In 30 healthy volunteers autologous blood was injected into the subcutaneous fatty tissue of the thigh and repetitive MRI scans of the artificial hematoma were performed on a 3T scanner. Due to the contrast behavior three relevant age ranges were defined and validated. The generated approach correctly classified all tested hematomas with an age less or equal 24 hours. The development of a reliable and objective MR-based age estimation method of hematomas is in the interest of justice. |
| 1617 | Assessment of the Myotendinous Junction After Injury in Elite Athletes Using 3D Ultrashort Echo Time Magnetization Transfer (UTE-MT) Imaging and Modeling | |
1University of California, San Diego, San Diego, CA, United States, 2Orthopedic Surgery, Scripps Clinic, San Diego, California, USA, 3Orthopedic Surgery, University of California, San Diego, United States, 4Radiology Service, VA San Diego Healthcare System, San Diego, United States |
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Myotendinous injuries are very common in sports, most often affecting the lower extremities. Both clinical examination and MRI have been widely used for the diagnosis and prognosis of acute myotendinous injuries. However, current paradigms remain insufficient as re-injury rates are as high as 34%. For elite athletes, the balance between rehabilitation time and risk of re-injury after return to play can be extremely challenging. Using conventional MRI techniques, clinical interpretation focuses on the evaluation of edema, fluid, and hemorrhage rather than the assessment of the injured/healing components of the myotendinous junction. Furthermore, immature and mature fibrous scar tissue as well as native tendon have very short T2 values and are “invisible” with clinical MRI, thus precluding their distinction and assessment. A technique to quantitatively characterize macromolecules in injured/healing myotendinous junctions could be particularly useful in recovering athletes. |
| 1618 | 2D Adiabatic UTE T1rho Imaging: Reduced Sensitivity to the Magic Angle Effect | |
1Radiology, University of California, San Diego, San Diego, CA, United States, 2Radiology Service, VA San Diego Healthcare System, San Diego, United States |
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Spin lattice relaxation in the rotating frame (T1rho) has been proposed as a biomarker to probe biochemical changes in cartilage. It reflects the slow interactions between motion-restricted water molecules and their local macromolecular environment, and provides unique biochemical information in the low frequency region ranging from a few hundred hertz to a few kilohertz. Changes to the extracellular matrix (ECM), such as proteoglycan (PG) loss, may be reflected in measurements of T1rho and T1rho dispersion. However, T1rho based on conventional continuous wave (CW) spin-locking preparation pulses demonstrate strong magic angle effects. Studies have shown an increase of over 100% in measured T1rho when the fibers were oriented from parallel to 54° relative to the B0 field. Adiabatic T1rho has been proposed to reduce the magic angle effect. However, many joint tissues such as the deep layers of articular cartilage, menisci, ligaments and tendons have short T2 relaxation and cannot be reliably imaged and quantified using the adiabatic T1rho sequence. In this study we aimed to develop a novel 2D adiabatic ultrashort echo time (UTE) T1rho sequence for magic angle insensitive imaging of both short and long T2 tissues in the joint. |
| 1619 | Efficacy of double inversion recovery MR imaging in evaluation of the synovium without contrast enhancement | |
1Radiology, Kyung Hee University Hospital at Gangdong, Seoul, Korea, Republic of, 2Radiology, Soonchunhyang University Bucheon Hospital, Buchoen, Korea, Republic of, 3Radiology, Kyung Hee University Medical Center, Seoul, Korea, Republic of |
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A double-inversion recovery (DIR) sequence simultaneously voids two sources of signals from two different tissues by applying two 180 degree inversion pulses before a signal acquisition. To investigate the efficacy of the DIR image in visualization of the knee synovium without contrast enhancement, contrast-enhanced T1-weighted fat suppressed images (CET1FS) were compared with DIR images in knee MR. Our results showed DIR images were well correlated with CET1FS images. |
| 1620 | The use of quantitative perfusion metrics in evaluating the relationship between perfusion level and intervertebral disc degeneration | |
1Department of Radiology,Renmin Hospital of Wuhan University, wu han, People's Republic of China, 2GE healthcare China |
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To explore the relationship between perfusion level and intervertebral disc degeneration.18 individuals underwent MRI exams including DCE-MRI, T2*mapping as well as conventional lumbar imaging. The cranial and caudal VSB and CEP perfusion parameters (Ktrans, Kep, Ve) as well as T2* values of discs were measured. it was found that T2* showed a negative correlation with the Pfirrmann grades, while showed no correlation with the perfusion parameters. |
| 1621 | A Prospective, Longitudinal Assessment of Adverse Local Tissue Reactions in Resurfacing Hip Arthroplasty Versus Primary Total Hip Arthroplasty | |
1Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY, United States, 2Department of Orthopedic Surgery - Hip Preservation Service, Hospital for Special Surgery, New York, NY, United States, 3Department of Orthopedic Surgery - Adult Reconstruction and Joint Replacement Service, Hospital for Special Surgery, New York, NY, United States, 4Department of Orthopedic Surgery - Adult Reconstruction and Joint Replacement Service - Adult Reconstruction and Joint Replacement Service, Hospital for Special Surgery, New York, NY, United States |
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Total hip arthroplasty devices are successful achieving pain reduction, but adverse local tissue reactions (ALTRs) frequently occur for metal-on-metal hip resurfacing arthroplasty (HRA) patients. This longitudinal study evaluated if HRA patients have a greater prevalence of ALTRs as compared to ceramic-on-poly (COP) patients. Images were acquired at 2 time points, with a 1 year interval, and evaluated for synovitis and ALTR. ALTR prevalence and synovial thickness was greater in HRA than COP subjects at both time points, with significant increases at the second time point. This study will permit a better understanding of the natural history in the development of ALTR near arthroplasty. |
| 1622 | In vivo assessment of trabecular bone in the proximal femur | |
1A*STAR-NUS Clinical Imaging Research Centre, Singapore, Singapore, 2Clinical Nutrition Research Centre, Singapore, Singapore, 3Institute of Materials Research and Engineering, Singapore, Singapore, 4School of Food and Nutrition, Massey Institute of Food Science and Nutrition, Massey University, New Zealand, 5Diagnostic Radiology, A-STAR-NUS Clinical Imaging Research Centre, Singapore, Singapore |
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Osteoporosis is a bone disease that predominately affects postmenopausal women. Routine screening of osteoporosis is performed by means of Dual X-ray Absorptiometry (DXA) which is limited by its inability to differentiate between cortical and trabecular bone, reduced accuracy due to overlying tissue and the use of ionising radiation. In this abstract, we investigate the use of MRI as an alternative, in a cohort of 95 Chinese-Singaporean postmenopausal women. Strong correlations with DXA measurements were observed, in addition to significant differences between the normal and osteopenic, normal and osteoporotic groups. |
| Exhibition Hall | Tuesday 8:15 - 10:15 |
| 1623 | Isotropic High Spatial Resolution fMRI Using Accelerated Variable Density Spiral and SLIDER | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, People's Republic of China, 2Philips Healthcare, Shanghai, People's Republic of China, 3FMRIB Centre, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, United Kingdom, 4Department of Biomedical Engineering, School of Medicine, Tsinghua University, People's Republic of China |
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fMRI with high spatial resolution is beneficial for studies in psychology and neuroscience, but is limited by various factors such as prolonged imaging time and low signal-to-noise ratio. In this work, we combined Dual-TRACER method with SLIDER technique to obtain up to 1mm isotropic fMRI image, while maintaining temporal resolution comparable with conventional acquisition. Using the proposed method, finger somatotopy maps were successfully located on a 3T scanner. |
| 1624 | Dual-Echo Cardiac Gating Spiral Sequence for Cervical Spine fMRI | |
1Stanford University, Stanford, CA, United States |
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We optimized a spiral sequence for dual-echo cardiac gating applied to cervical spine fMRI. Dual-echo obviates dependency on variable initial longitudinal magnetization that would, otherwise, require T1 correction. Spiral acquisition allows short echo time and readout duration which maximizes SNR and BOLD contrast. Our technique improves tSNR and fMRI activation when compared with ungated sequence. |
| 1625 | Frequency offset correction for accelerated 3D-EPI with segmented reference data | |
1Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom, 2Huntington's Disease Research Centre, Institute of Neurology, UCL, London, United Kingdom, 3Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany |
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3D-EPI is beneficial for real-time fMRI applications because the acquisition can be accelerated in both the in-plane and through-plane phase-encoded directions significantly increasing temporal resolution. Fully-sampled reference data are required in order to map coil sensitivities and unfold the aliased images that result. Acquiring these data with a segmented EPI readout matches the EPI-related distortions and dropouts between the un-accelerated reference data and the accelerated fMRI data. However, systematic differences in eddy-current-related phase between the segments can introduce errors during frequency offset correction (employed to correct for slow frequency drifts) unless accounted for. Here we present a simple correction scheme that greatly improves the tSNR of the time series. |
| 1626 | Echo-time optimization in Spin Echo EPI fMRI using BOLD-sensitivity models and hypercapnic manipulation at 3T | |
1Dept. of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2Rotman Research Institute, Toronto, ON, Canada |
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The preferred echo-time (TE) used in most spin-echo EPI (SE-EPI) fMRI studies is approximately the tissue T2 value (65–100ms at 3 T). In this study, we use a hypercapnia paradigm with SE-EPI and three metrics of BOLD-sensitivity to model the TE that maximizes BOLD detection at 3 T. We concluded that while the maximal absolute BOLD contrast occurs near tissue T2 (~75ms), a TE of 55ms both maximizes tissue CNR and minimizes BOLD effects from non-neuronal sources. |
| 1627 | Local B0 temporal instability detected using a modified Multi-Echo GRE-EPI sequence with Flipped-Blips (MEPI-FB): application to fMRI with visual presentation of faces | |
1Department of Physics, University of Pisa, Pisa, Italy, 2Imago7 Research Center, Pisa, Italy, 3GE Healthcare, Pisa, Italy, 4GE Healthcare, Orsay, France, 5GE Global Research, Munich, Germany, 6IRCCS Stella Maris, Pisa, Italy |
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Field-mapping techniques using a reference scan allow accurate distortion correction of EPI data. However, due to the strong B0 dependency with head motion and other physiological artefacts in fMRI acquisitions, the reference field-map does not adequately correct for dynamic non-linear changes in image intensity. In this work we show the feasibility of a method to map temporal variations of the B0-field at 7 Tesla, using a high-resolution Multi-echo EPI sequence, acquiring three echo-modules with reverse phase-encoding direction on the second echo. The robustness of the method was tested during an fMRI acquisition with visual presentation of faces. |
| 1628 | Less may be better: comparison of Multi-Echo-ICA de-noising for three and four echo EPI acquisitions in studies of seed-based functional connectivity | |
1Centre for Neuroimaging Sciences, IoPPN, King's College London, London, United Kingdom |
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This work is a formal comparison between different echo acquisitions (3 and 4 echo) for the use with multi-echo independent component analysis de-noising of resting-state functional MRI data. We look to evaluate and determine the optimal acquisition required for de-noising of resting state data which is often plagued with artifacts and noise. |
| 1629 | Cortical Depth-Dependent Physiological Noise Cleaning in High-Resolution VASO Imaging | |
1Section on Functional Imaging Methods, NIH/NIMH, Bethesda, MD, United States, 2section on functional imaging methods, NIH/NIMH, 3NIH/NIMH |
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As functional analyses move toward finer detail and higher resolution, sources of noise that were nuisances are now becoming more significant. While noise removal is well studied in lower-resolution, gradient echo BOLD-weighted imaging, it is not as well understood in high resolution VASO. We examine the efficacy of physiological noise cleaning methods that are commonly used in many fMRI studies. |
| 1630 | Validation of Motion Correction with Multiband SLOMOCO using Multiband SimPACE | |
1The Cleveland Clinic, Cleveland, OH, United States |
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A Multiband version of the SimPACE sequence was developed to validate multiband SLOMOCO motion correction method. With the increasing use of simultaneous multi-slice acquisition techniques to acquire fMRI data more efficiently, the traditional motion correction methods need to be modified or improved to better correct subject motion in fMRI. This preliminary study showed that multiband SLOMOCO can detect the outermost slice motion better than single-slice SLOMOCO. Multiband SimPACE is a promising sequence to further facilitate the improvement of motion correction methods including multiband SLOMOCO. |
| 1631 | Impact of prospective motion correction in 7T fMRI studies | |
1DZNE, Magdeburg, Germany, 2Institute of cognitive neurology and dementia research (IKND), Magdeburg, Germany, 3Department of Biomedical Magnetic Resonance, Institute of Experimental Physics, Otto-von-Guericke-University, Magdeburg, Germany, 4Center for Behavioral Brain Sciences, Magdeburg, Germany, 5Leibniz Institute for Neurobiology, Magdeburg, Germany |
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Recently, more fMRI studies are aiming to assess the role of small anatomical regions of the brain in cognitive processes which requires sub-millimiter voxel resolution. At high resolution rigid body motion during the acquisition plays a significant role. The aim of this study is to assess the potential benefits of correcting for subject motion introduced distortions and image degradation prospectively in fMRI studies. This study demonstrates that prospective motion correction increases tSNR and therefore increases sensitivity. These results increment the potential applications of fMRI to unveil, more accurately, the role of smaller parts of the brain in different cognitive processes. |
| 1632 | Phase-offset Multiplanar Echo-planar Imaging (POMP-EPI) to Accelerate fMRI Acquisition without Parallel Imaging | |
1Stanford University, Stanford, CA, United States |
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Simultaneous-multislice (SMS) has significantly improved fMRI acquisition due to its increase in SNR efficiency. However, SMS requires parallel-imaging in the slice-direction, which may be inapplicable due to the scarcity of receiver-coils with adequate sensitivity in the slice-direction. Hence, we propose the POMP-EPI method, which accelerates fMRI acquisition without using parallel-imaging. POMP-EPI works by using Gz-gradient blips in an EPI sequence to shift each of the simultaneously excited slices into different regions of an extended FOV, such that no aliasing occurs, resulting in simple reconstruction of images, shorter TRs, and increased SNR efficiency. |
| 1633 | High-resolution semi-adiabatic spin-echo fMRI at 7T. | |
1Bioengineering, Stanford University, Stanford, CA, United States, 2Stanford University, Stanford, CA, United States, 3Radiology, Stanford University, Stanford, CA, United States, 4Radiology, Neuroscience, Mount Sinai, NY, United States |
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Spin-echo fMRI provides greater functional specificity than gradient-echo fMRI, but suffers from lower sensitivity. At higher field strengths, the spin-echo signal contribution from smaller capillaries, closer to the site of neural activity, increases. A major challenge of MRI at high field strengths, however, is increased B1 inhomogeneity, which can impact the performance of RF pulses, in particular refocusing pulses. Here, we use an adiabatic refocusing pulse and a matched-phase excitation pulse to perform high-resolution spin-echo fMRI at 7T. We compare the results to a similar gradient-echo acquisition, and show sharper activation better localized to gray matter in the spin-echo results. |
| 1634 | Simultaneous brain and spinal cord fMRI using slice-based dynamic shimming | |
1Bioengineering, Stanford University, Stanford, CA, United States, 2Stanford University, Stanford, CA, United States |
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Simultaneous brain and spinal cord fMRI would be beneficial for studying the nervous system, but is challenging due to the poor B0 homogeneity and small size of the spinal cord. Here, we used dynamic shimming and reduced FOV imaging to address these issues. We obtained improved T2*-weighted images of brain and spinal cord with high clarity. We validated the method for fMRI applications using an fMRI experiment with a fist-clenching task, in which we obtained activation in all regions expected to be involved in the task, including the motor cortices, cerebellum, and C6-C8 spinal cord region. |
| 1635 | Mu opioid receptor activation signatures on brain activity and connectivity by fMRI in mice | |
1Department of Psychiatry, Douglas Mental Health University Institute, Montreal, QC, Canada, 2Center for Translational Neuro-Imaging, Northeastern University, Boston, MA, United States |
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Mu opioid receptors (MORs) mediate the strong analgesic and rewarding effects of morphine. We used non-invasive imaging fMRI in wild-type and MOR knockout mice to assess MOR-dependent effects at the scale of the whole brain. Here, we present striatum seed-based signatures identified by BOLD activation map, functional connectivity and directionality. We identified MOR-specific activation of the striatum between 2 and 7 minutes after morphine administration. Furthermore, during this time interval, the brain connectivity was altered by morphine in wild type but not mutant mice. This is the first reported on-target morphine activation signature in the striatum of live animals. |
| 1636 | Altered Spontaneous Brain Activity in Children with type 1 Gaucher disease: a Resting-state fMRI Study | |
1Beijing children's hospital, Beijing, People's Republic of China, 2Research Center for Brain-inspired Intelligence, Institute of Automation, Chinese Academy of Sciences, Beijing, People's Republic of China |
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This is the first study to examine differences in spontaneous neural activity between GD patients and healthy controls. Our results indicate that decreased of neural activity in motor area; increased neural activity in the olfaction-, vision- and algesthesia -related structures; dysfunction of neural activity in emotion- , recognition- and speech- related structures and cerebellum. These results promote a further understanding of underlying neurophysiological mechanisms in the intrinsic brain of GD type I, which will aid in the development of treatment plans for GD type I patients that address both physical and psychological concern and preventing neurological disease in early stage. |
| 1637 | Resting-state network patterns in extremely preterm born young adults | |
1UCL, London, United Kingdom, 2Institute for Women's Health, University College Hospital |
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Rates of extreme-prematurity are increasing worldwide. Neuroimaging studies allow us to investigate the underlying tissue substrate of the broader neuropsychological differences observed in preterm cohorts; but the long-term neuroimaging phenotype of extremely-preterm adolescents is relatively unknown. Here we investigate resting-state functional MRI to establish if there is a variability in the pattern of functional networks in extremely-preterm born 19 year-olds relative to a group of their term-born peers. |
| 1638 | Comparison of fMRI analysis methods for heterogeneous BOLD responses in block design studies | |
1Stanford University, Palo Alto, CA, United States |
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Improper selection of analysis methods can lead to significant errors when analyzing fMRI data with heterogeneous BOLD responses. Here, we used rodent optogenetic fMRI data and simulations to investigate different analysis methods’ detection and characterization performance. Our results show that, in the presence of heterogeneous BOLD responses, conventionally used GLM with a canonical basis set leads to considerable errors, while the gamma, finite impulse response, B-spline, and Fourier basis sets show robust performance. |
| 1639 | Differential Reduction of Repertoire of Functional Patterns in Sensory and Cognitive Neuronal Systems in Propofol Anesthesia | |
1Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 2Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States, 3Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 4Neurology, Medical College of Wisconsin, Milwaukee, WI, United States, 5Anesthesiology, University of Michigan, Ann Aobor, MI, United States |
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We propose that the diversity of distinct functional patterns of the brain can be quantified by the variance explained by the first few principal components of regional voxel functional imaging signals. We report that propofol sedation is associated with a global reduction of repertoire of functional patterns. While sensory-processing-related and high-order cognitive-processing-related brain regions both showed a reduction during propofol sedation, it was the changes in the sensory-processing-related regions that correlated the loss and return of consciousness. The findings provided important insights into anesthetic modulation of different neuronal systems and the neural correlates of consciousness at the systems level. |
| 1640 | Control study of arterial spin labeling and multi-phase enhancement technique in evaluation of renal blood flow in different age population | |
1The First Affiliated Hospital of Chengdu Medical College, Chengdu, People's Republic of China |
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This study is aim to assess ability of arterial spin labeling technique(ASL) and multi-phase enhanced magnetic resonance (MCE-MR) of evaluate renal perfusion in different ages population with normal renal function by 1.5T MRI. Meanwhile, to evaluate difference between ASL and MCE-MR of renal perfusion. |
| 1641 | Predicting Diffusion Tensors from Resting-State Functional MRI | |
1Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China |
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It has been recently reported that the spatio-temporal correlation of white matter BOLD signals in resting-state functional MRI (rs-fMRI) can be captured using functional correlation tensors (FCTs). FCTs exhibit anisotropy information similar to diffusion tensor imaging (DTI). In this work, we employ a patch-based strategy to improve the noise-robustness of FCTs. Then, we adopt regression forest to learn a mapping from FCTs to DTs. Testing using unseen images, the predicted DTs show high similarity with the actual DTs. This validates the fact that FCTs carries information that is highly correlated with DTs. |
| 1642 | Group differences in default mode network connectivity not just anti-correlation depend on choice of nuisance regressor model | |
1Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Nottingham, United Kingdom, 2Arthritis Research UK Pain Centre, University of Nottingham, Nottingham, United Kingdom, 3Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom |
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Resting state fMRI is prone to a large range of factors affecting the acquired data and processing pipelines available, which can impact on the outcome of a study. This study assessed the similarity of time series taken from aCompCor outputs to global signal to assess the inclusion of a ‘proxy’ global signal and its effect on group-wise tests of default-mode connectivity. The first components of both white matter and CSF were highly correlated with global signal and regressing either global signal or aCompCor outputs altered group-comparisons of functional connectivity. Future studies should scrutinise and report their postprocessing pipelines clearly. |
| 1643 | Reduction of Scanner’s Noise in Recorded Voice Responses Using an Inline Reference Scanner’s Noise for Automated Measurement of Voice Response Time in Overt Speech fMRI | |
1Institute of Applied Life Sciences, Human MR Center, University of Massachusetts Amherst, Amherst, MA, United States, 2Department of Communication Disorders, University of Massachusetts Amherst, Amherst, MA, United States |
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The overt voice response in fMRI is critical to aphasia neuroimaging studies. A commercially available active noise cancelling microphone makes this application possible. However, an automated measurement of the voice response time is not reliable due to remaining scanner noises. The incomplete noise cancellation is due to uneven slice time intervals in the EPI sequence. The remaining noise was reduced using a post-processing approach based on a previously published method that used a template of a reference noise. The response time was measured from the noise-reduced voice signal using an amplitude and duration threshold after an envelope filtering. |
| 1644 | Distortion-free fMRI using multi-slice 2D-bSSFP at 7 tesla | |
1CIBM, EPFL, Lausanne, Switzerland |
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Balanced Stead-State Free Precession (bSSFP) techniques have been proposed as an alternative to GE-EPI to address the problem of co-registration between functional/structural scans at high field. However, 3D imaging is suboptimal for localized fMRI applications, and result in distortions, blurring, and increased sensitivity to motion/physiological noise. Here, we propose to use 2D-bSSFP and cartesian readouts and demonstrate that (i) bSSFP signal characteristics are preserved in a new steady-state, (ii) resting-state fMRI (RS-fMRI) can be performed with 2D-bSSFP, (iii) the 2D-bSSFP temporal SNR levels with that of 3D-bSSFP, resulting in - at least - equal fMRI performances at high field. |
| 1645 | 7T-fMRI: Faster temporal resolution increases BOLD sensitivity and fMRI-based decoding performance specifically at high-spatial resolution | |
1Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia, 2Department of Electrical & Electronic Engineering, The University of Melbourne, Australia, 3Imaging Division, Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 4Department of medicine and Neurology, The University of Melbourne, Australia, 5Siemens Healthcare, Melbourne, Australia |
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The benefits of ultra-high fMRI are maximized at high spatial resolutions with less physiological noise contribution. However, increasing the temporal resolution is often avoided at such high spatial resolutions due to limitations in the temporal signal-to-noise-ratio (tSNR). We investigated the effects of varying spatial and temporal resolutions on fMRI sensitivity measures at 7T, and their implications on an fMRI application, Brain-Computer-Interface (BCI). We demonstrate overall BOLD sensitivity increased with temporal resolution despite the tSNR decrease specifically at high-spatial resolution 7T-fMRI. We further demonstrate that this sensitivity increase also improved the accuracy of linear classifiers commonly used in BCIs. |
| 1646 | Automatic physiological noise estimator with PESTICA in HCP resting state fMRI data | |
1Radiology, Cleveland Clinic, Cleveland, OH, United States |
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Recent work with accelerated HCP rs-fMRI data shows strong correlation with non-neuronal noise sources, and their noise patterns appears to be linked across simultaneously excited slices (SMS)1,2. To correct for these noise sources, a measurement of physiologic cycles is needed, which can be supplied by monitoring, but not always available or accurate, or PESTICA which estimates physiological signal fluctuation from EPI data itself3. If the noise is dependent on SMS location, PESTICA could more efficiently detect physiologic signal fluctuation in HCP fMRI. In this study, we modified PESTICA for the SMS acuisition and evaluated performance compared with monitored physiological signals |
| 1647 | Investigating Altered Brain Functional Network in Alzheimer’s Disease Using a Joint Framework of Graph Theoretical Analysis and Machine Learning | |
1Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli, Taiwan, 2Department of Computer Science, National Chiao Tung University, Hsinchu, Taiwan, 3GE Healthcare, Taiwan, 4GE Healthcare MR Research China, Beijing, People's Republic of China, 5Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taiwan |
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The progressive decline in cognitive abilities occurred in the early stage of Alzheimer’s disease (AD) is often difficult to be distinguished from the symptoms of mild cognitive impairment (MCI). This study incorporated graph theoretical analysis and machine learning approach to investigate the alterations of brain functional network in AD. Statistical approach demonstrated regions with significantly altered network characteristics, which were also reported to be linked to AD in previous studies. Machine learning approach using TensorFlow also showcases the significant discriminative power of the brain network measures. Future work includes incorporation of other type of network measures, behavior and biochemical assessments, and more complex deep learning models. |
| 1648 | Modeling serial correlations in fMRI time series collected by faster TRs | |
1Electrical Engineering & Radiology, Stanford University, Stanford, CA, United States, 2Electrical Engineering & Radiology, Stanford University, CA, United States |
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Serial correlations of fMRI time series are altered at faster TRs (<1s) due to reduced signal to noise ratio per time frame. Thus, caution is advised when utilizing serial correlation models describing long TR (2~3s) conditions with fast acquisitions. Here, we show that statistical models alternative to the commonly used first order auto-regressive (AR) model – AR2 and AR1moving-average(MA)1 model —can achieve reasonable fitting for short TR data and improve the accuracy of activation estimates. Potential model bias can be further reduced by low-pass filtering. |
| 1649 | Measurement of high frequency band signals by ultra-high temporal resolution imaging in task-based fMRI | |
1Kansei Fukushi Research Institute, Tohoku Fukushi University, Sendai, Japan, 2GSIS and RIEC, Tohoku University, Sendai, Japan |
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Recent advances in MRI technique such as the multiband sequence have made fast sampling available up to 100-200 ms TR for whole brain acquisition. However, its usefulness is limited because there is not found any significant functional changes needed to be sampled with that short TR. In this study, we challenged to detect task-induced fast signals with the ultra-high temporal resolution imaging with 100 Hz sampling rates. |
| 1650 | Correction of EPI geometric distortion in slice direction using reversed slice-select gradients and topup | |
1A.A. Martinos Center for Biomedical Imaging, MGH/Harvard, Charlestown, MA, United States, 2Division of Health Sciences and Technology, Harvard-MIT, Cambridge, MA, United States |
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Conventional single-shot Echo Planar Imaging (EPI) protocols used by fMRI studies suffer from geometric distortion occurring in the phase-encoding direction. Ultrahigh field (>3T), high-resolution fMRI using thin slices requires decrease of the slice-encoding bandwidth, which may lead to the additional geometric distortions and “slice bending” in the slice-encoding direction. Here we use gradient-echo (GRE) EPI sequence that allows the polarity of the slice-select gradient to be flipped between positive and negative values to demonstrate this effect and to enable the application of FSL’s topup to perform distortion correction. This correction will further improve geometric alignment of the EPI data with anatomical reference data used in fMRI studies. |
| 1651 | Improved specificity of high-resolution fMRI with surface-based cortical ribbon smoothing | |
1Martinos Imgaing Center, MGH/Harvard, Charlestown, MA, United States, 2Orchard Scientific, Somerville, MA, United States, 3Division of Health Sciences and Technology, Harvard-MIT, Cambridge, MA, United States |
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High-resolution fMRI data enables strategies to improve spatial specificity of the measured fMRI activations through anatomically-informed sampling. Here we demonstrate that cortical surface-based smoothing of high-resolution data can improve the specificity of fMRI activations by simultaneously canceling thermal noise through spatial averaging while avoiding physiological noise contamination from superficial CSF and signal dilution from subjacent white matter. By combining both tangential and radial smoothing using our surface-based analysis framework, specificity of responses to a breathold challenge can be similar in high-resolution data natively sampled at 1.1 mm iso. and unsmoothed data at a conventional resolution of 3.0 mm iso. |
| 1652 | Optimal resolution for searchlight classification of BOLD fMRI data. | |
1Advanced MRI section, LFMI, NINDS, National Institutes of Health, Bethesda, MD, United States |
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Information-theoretic approaches to BOLD fMRI analysis, like the Searchlight method for multivariate pattern analysis (MVPA), suggest that distinctive local patterns of BOLD signal on a spatial scale of millimeters carry information that allows the classification or decoding of perceptual stimuli. In this study high-resolution (1.2mm) BOLD fMRI experiments at 7T combined with naturalistic movie stimuli reveal that Searchlight decoding primarily relies on a neurogenic BOLD signal that is spatially smooth, unlike the accompanying physiological artifacts. As a result the optimal fMRI resolution peaks between 2 and 4mm, a voxel size well above the technical limits of fMRI. |
| 1653 | Optimization of white matter fMRI analysis using physiologically derived hemodynamic response functions | |
1School of Mechatronic Systems Engineering, Simon Fraser University, Surrey, BC, Canada, 2School of Mechatronic Systems Engineering, Simon Fraser University, 3Fraser Health Authority, Surrey, BC, Canada, 4Department of Physics, The University of British Columbia, Vancouver, BC, Canada, 5Department of Radiology, The University of British Columbia, Vancouver, BC, Canada, 6School of Computing Science, Simon Fraser University, Burnaby, BC, Canada, 7School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada |
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White matter functional MRI has been successfully demonstrated in studies using high-field scanners and customized sequences. In the current study, we demonstrated that conventional GRE EPI using 3T MRI replicated white matter activation in the corpus callosum at both the group and individual levels (61.5% of individuals). Importantly, hemodynamic response functions (HRF) using delayed-onset improved sensitivity to white matter activation over the canonical HRF developed from gray matter activity. The results suggest that white matter fMRI studies, which are increasingly reported in the literature, benefit significantly from optimization in acquisition and analysis methods. |
| 1654 | Characterization of structural and functional connectivity in epilepsy by integrating diffusion and functional tensor imaging | |
1Department of Computer Science, Chengdu University of Information Technology, Chengdu, People's Republic of China, 2Institute 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 and Computer Science, Vanderbilt University, Nashville, TN, United States, 5Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 6Department of Neurology, Vanderbilt University, Nashville, TN, United States |
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Although previous studies have tried to combine diffusion tensor imaging (DTI) and resting-state functional magnetic resonance imaging (rs-fMRI) in clinic studies, they only use rs-fMRI for gray matter and DTI for white matter pathways. In this study, DTI and rs-fMRI were leveraged for conjoint analysis of structural and functional connectivity in white matter. The results showed that in temporal lobe epilepsy patients, there was an increased functional fractional anisotropy in contralateral fiber bundles, which were accompanied by increases in mean diffusivity in ipsilateral bundles. This reflects complex interactions between disease evolution and compensatory adaption. |
| 1655 | On the relation between Global Signal Normalization, Global Signal Subtraction, and Global Signal Regression in Resting-State fMRI | |
1UCSD Center for Functional MRI, La Jolla, CA, United States |
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In resting-state fMRI, global signal regression (GSR), global signal subtraction (GSS) and global signal normalization (GSN) are widely used nuisance removal methods. So far these techniques have been treated as distinct operations and the relation between them has not been clearly described. In this paper, we mathematically and empirically show that GSS and GSN are nearly identical processes in resting-state fMRI. We further show that in terms of resting-state functional connectivity maps, GSS and hence GSN are similar processes to GSR when considering seed time courses that have a good fit to the global signal time course. |
| 1656 | Global Signal Regression acts as a Temporal Downweighting Process in Resting-State fMRI | |
1UCSD Center for Functional MRI, La Jolla, CA, United States |
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Global signal regression (GSR) is a controversial preprocessing method in resting-state fMRI. It has been claimed that the process can introduce artifactual anti-correlations in resting-state connectivity maps. However, a consensus regarding its use has been lacking, due in part to the difficulty in understanding its effects. We show that GSR can be well approximated by a temporal downweighting of the voxel time series, where the weighting factor is a function of the global signal magnitude and is uniform across space. This helps address the concerns about GSR and provides a novel framework for understanding its effects on resting-state data. |
| Exhibition Hall | Tuesday 8:15 - 10:15 |
| 1657 | Quantifying the dynamics of cerebral blood flow, oxygen metabolism, and deoxygenated blood volume with a combined normoxia/hyperoxia method | |
1Neurosciences Graduate Program, University of California, San Diego, La Jolla, CA, United States, 2Medical Scientist Training Program, University of California, San Diego, La Jolla, CA, United States, 3Center for Functional MRI, University of California, San Diego, La Jolla, CA, United States, 4Psychiatry, University of California, San Diego, 5Center for Human Development, University of California, San Diego, 6Radiology, University of California, San Diego |
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To better understand the dynamics of the BOLD response in terms of CBF, CMRO2, and deoxygenated blood volume, we used a combined normoxia/hyperoxia approach to untangle their relative contributions. This method was applied to both the positive activation response and the post-stimulus undershoot, the origins of which are still debated. A simple model of the BOLD response based on flow, metabolism, and volume, modified to include the effects of hyperoxia, was applied. For the origin of the undershoot, these data provide strong evidence for a CBF undershoot, moderate evidence for elevated CMRO2, and no evidence for elevated CBV (Balloon Model). |
| 1658 | Improving qBOLD based measures of brain oxygenation using hyperoxia BOLD derived measures of blood volume | |
1FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom |
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Measurements of deoxygenated blood volume (DBV) via the streamlined-qBOLD technique are larger than typically reported in the literature, resulting in underestimation of oxygen extraction fraction (OEF). In this study we address this limitation by acquiring a separate measurement of DBV using the BOLD response to the administration of oxygen, which has been shown to be specifically sensitive to venous blood volume. By combining measurements of the reversible transverse relaxation rate, R2′, and DBV to measure OEF, we were able to show better agreement with whole brain OEF from the TRUST method than OEF measured with streamlined-qBOLD. |
| 1659 | Measurement of cerebral venous blood oxygen saturation via T2* fitting with velocity encoded phase imaging | |
1CUBRIC, Cardiff University, Cardiff, United Kingdom |
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Measurements of cerebral venous O2 saturation with MRI would enable use to estimate brain O2 consumption, a marker of brain activity. Here we propose a new method with this aim, that exploits a Fourier velocity encoding scheme combined with multi-echo acquisitions for estimating 𝑇2* and then, through calibration curves, O2 saturation. Synthetic data are analysed and pilot data from resting state and visual stimulus acquisitions (two subjects) are reported. The new method is shown to supply plausible estimates of baseline levels and changes in O2 saturation in the sagittal sinus following stimulation. |
| 1660 | Estimation of cerebral metabolic rate of oxygen from measured hemodynamic response function and cerebral blood flow using arterial spin labeling | |
1Neuroscience, Baylor College of Medicine, Houston, TX, United States |
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In the brain, brief neural activity creates changes in local blood flow (CBF) and oxygen uptake (CMRO2). Functional magnetic resonance imaging (fMRI) can measure these changes as a blood oxygenation level dependent (BOLD) signal. The BOLD response to brief stimulations is often termed the hemodynamic response function (HRF). We recently proposed the Arterial Impulse model for the HRF based on a combination of underdamped CBF and CMRO2 responses. Here, we used arterial spin-labeling (ASL) to measure both the BOLD HRF and CBF, and then used our model to obtain estimates of the CMRO2 time course. |
| 1661 | Correcting for imperfect spin echo refocusing in gas-free fMRI calibration | |
1Montreal Neurological Institute, McGill University, Montreal, QC, Canada, 2Radiology and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, 3FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 4Cornell MRI Facility, Cornell University, Ithaca, NY, United States |
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Gas-free calibration is an appealing new alternative for calibrated fMRI. Using simulations, we determined that estimates of the calibration parameter, M, obtained directly by estimating R2’ with asymmetric spin echo imaging, are negatively biased. This is due to imperfect spin echo refocusing of spins diffusing in the extravascular space. When we modelled the spin echo attenuation as a quadratic-exponential decay, the imperfect refocusing effects were accurately accounted for over intermediate to large vessel sizes. When tested in vivo, increases in M were observed when using the quadratic model, however, additional sources of decay also contributed to M. |
| 1662 | Dual-calibrated fMRI measurement of resting capillary and venous blood volumes | |
1CUBRIC, Cardiff University, Cardiff, United Kingdom |
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The potential for dual-calibrated fMRI to provide quantitative estimates of physiological parameters has been increasingly investigated. We present a novel analysis methodology to estimate capillary (CBVcap) and venous (CBVv) blood volumes. These parameter estimates are made in addition to standard physiological parameters (cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2)). Maps of CBVcap demonstrate a marked reduction in the appearance of large vessels (compared to CBVv data) and show significant correlations with CBF and CMRO2. These findings suggest an important role for CBVcap for assessing cerebral metabolic function and neurovascular coupling. |
| 1663 | Measurements of the flow component of the hemodynamic response function in human cerebral cortex | |
1Neuroscience, Baylor College of Medicine, Houston, TX, United States |
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Brief cortical neural activity creates changes in local blood flow and oxygen uptake. Functional magnetic resonance imaging can measure this neurovascular coupling as a blood oxygen level dependent (BOLD) signal. The BOLD response to brief stimulation is termed the hemodynamic response function (HRF). We developed a computational model for the BOLD HRF, which predicts that the flow component of the HRF is a simple underdamped sinusoid. To test this prediction, we used arterial spin labeling to measure both CBF and BOLD responses in human cortex with high spatial and temporal resolution. Results confirm a significant flow undershoot in five subjects. |
| 1664 | Rapid cerebrovascular reactivity mapping: Comparison of a sinusoid protocol with the conventional block protocol | |
1FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 2Department of Physics, University of Oxford, Oxford, United Kingdom, 3Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom |
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Cerebrovascular reactivity (CVR) mapping is a useful technique for stress testing the brain. However, clinical adoption of CVR mapping has so far been hindered by relatively long scan durations of 7-12mins. In this study we show that by using a sinusoidal carbon dioxide stimulus in place of a conventional block protocol, equivalent CVR maps can be produced in a much shorter scan duration of 3-5mins. |
| 1665 | Towards self-calibrated functional connectivity mapping | |
1Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States, 3Siemens Healthcare, Baltimore, MD, United States, 4Neurological Surgery, University of Texas Southwestern Medical Center, Dallas, TX, United States |
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The BOLD signal in functional connectivity MRI(fcMRI) may be affected by non-neural factors, such as vascular function. In this study, we utilized a multiparametric mapping method to measure functional connectivity(FC) maps and cerebrovascular reactivity(CVR) concomitantly, and examined the relationship between these two indices in both healthy volunteers and patients with cerebrovascular disease. Significant correlations were found between FC and CVR across brain regions, suggesting that cerebrovascular function should be accounted for when using BOLD fcMRI to assess brain functions. Concomitant acquisition of neural and vascular MRI may allow calibration/normalization of FC signal and more accurate estimation of brain functional connectivity. |
| 1666 | Clinical mapping of cerebrovascular reactivity using MRI: a framework for reaching consensus | |
1Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom, 2Hotchkiss Brain Institute, Department of Radiology, University of Calgary, Canada, 3Institute of Medical Science, University of Toronto, Canada, 4Radiological Sciences Laboratory, Stanford University, United States, 5C.J. Gorter Center for High Field MRI, Radiology, Leiden University Medical Center, Netherlands, 6Centre for Neuroscience Studies, Queen’s University, Canada, 7Section on Funtional Imaging Methods, National Institute for Mental Health, United States, 8Montreal Neurological Institute, McGill University, Canada, 9Institute of Biomedical Engineering, University of Oxford, United Kingdom, 10PERFORM Centre, Concordia University, Canada, 11FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom |
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There is increasing clinical interest in mapping cerebrovascular reactivity (CVR), the response of cerebral blood vessels to a carbon dioxide stimulus. However, the application of CVR mapping varies greatly across sites due to a lack of methodological standardisation. We established an international network of over 100 researchers and administered a survey to establish current practice. Guided by QIBA and UPICT protocols, we developed a framework for reaching consensus, and identified areas where agreement already exists. Immediate achievable targets and long-term aims for the CVR community are defined, with the ultimate goal of establishing CVR as a robust clinical imaging marker. |
| 1667 | Corticolimbic Hyperresponse to Emotion and Glutamatergic Function in People with High Schizotypy: A Multimodal fMRI-MRS Study | |
1Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom, 2Centre for Brain Health, University of British Columbia, BC, Canada, 3Social Brain Lab, Netherlands Institute for Neuroscience, an institute of the Netherlands Academy for Arts and Sciences KNAW, Amsterdam, Netherlands, 4Psychology, University of Amsterdam, Amsterdam, Netherlands |
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Our recent functional magnetic resonance (fMRI) studies reported that elevated neural responses to emotional stimuli are present in the early stages of psychotic disorders and in individuals at clinical high risk for psychosis. Our present study combined fMRI with proton magnetic resonance spectroscopy (1H-MRS) at 3T and shows that corticolimbic hyperresponsivity to emotion is directly related to glutamate concentrations in healthy people with subclinical psychotic-like experiences. These data not only support preclinical animal models of psychosis by demonstrating an important link between corticolimbic neurophysiology and neurotransmission, but also suggest a scientific basis for future development of novel interventions focused on emotional regulation to prevent or delay progression from the vulnerability to the psychotic state |
| 1668 | A novel role of intrinsic astrocytic calcium spikes to mediate brain states through central/dorsal thalamic nuclei | |
1Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 2Graduate Training Centre of Neuroscience, International Max Planck Research School, University of Tuebingen, Tuebingen, Germany |
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The astrocytic Ca2+ signal could be simultaneously acquired with either BOLD-fMRI or LFP signal in the rat cortex under anesthesia. Intrinsic astrocytic Ca2+ bursts spikes were detected in the cortex with suppressed spontaneous LFP and negative BOLD fMRI signal. These astrocytic Ca2+ spike events were different from the normal activity-evoked Ca2+ signal and also differentiate themselves from the lesion/stimulation-induced large-scale depolarization or spreading depression given the instantaneous whole-brain pattern and correlation with the thalamic LFP. The intrinsic astrocytic Ca2+ spike may mediate the brain states through the arousal thalamic pathway. |
| 1669 | Defining the challenges in awake rat fMRI | |
1Emory University/Georgia Institute of Technology, Atlanta, GA, United States |
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Awake rat fMRI has been growing in popularity in recent years because it eliminates confounds associated with the use of anesthesia. However, issues arising from animal restriction have not been completely identified or recognized by the research community. We conducted a pilot study on immobilization training for awake rat fMRI studies and provide some relevant experiences that highlight potential issues to be resolved. |
| 1670
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Neural and Physiological Responses to Vagus Nerve Stimulation in rats | |
1Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 2Electrical and Computer Engineering, Purdue University, West Lafayette, IN, United States, 3Psychological Sciences, Purdue University, West Lafayette, IN, United States |
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Vagus nerve stimulation (VNS) is an electroceutical treatment for both brain and visceral organs disorders. To better understand its function in autonomic brain-body interaction, we applied electrical stimulation to the vagus nerve to perturb brain activity and visceral organ physiology. By simultaneously measuring the VNS-induced brain and physiological responses, we separated the afferent neuronal and efferent physiological effects of VNS on the blood oxygen level dependent functional magnetic resonance imaging responses and mapped part of the brain’s autonomic control networks modulated by VNS. This work offers a unique way to characterize the |
| 1671 | Is sevoflurane a viable alternative anaesthetic for functional MRI in mice? | |
1Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland |
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In preclinical fMRI, the volatile anaesthetic isoflurane is valued for its ease of use and controllability, and is frequently applied to prevent anxiety and subject motion. Yet, isoflurane increases cerebral blood flow and particularly in mice it limits cerebrovascular response to neural activity, thus curtailing fMRI. Sevoflurane, a close relative to isoflurane, has been reported to be less vasodilatory. Hence, we evaluated whether sevoflurane could serve as an improved anaesthesia modality for fMRI in mice. Perfusion MRI however revealed high basal cerebral perfusion and restricted cerebrovascular reserve capacity in an acetazolamide-induced hypercapnic challenge akin to those previously reported for isoflurane. |
| 1672 | Frequency-dependent hemodynamic response to somatosensory stimulation in ketamine-anesthetized mice | |
1Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, Korea, Republic of, 2Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan Universiy, Suwon, Korea, Republic of, 3Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of |
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Optimizing parameters of electrical forepaw stimulation is necessary to investigate biophysical and molecular properties of fMRI signals. However stimulation parameters and anesthesia in mice are not well-defined. Here we introduced ketamine anesthesia in mice. Initially, forepaw stimulation frequency was refined with for CBV-weighted OIS experiments. To translate electrical stimulation parameters from OIS into BOLD fMRI, we tested two stimulation frequencies. Application of our sensory stimulus parameters evoked well-localized and robust BOLD fMRI signals in ketamine anesthetized mice. |
| 1673 | Non-invasive evaluation of functional and structural connectome changes in the mouse brain related to drug-induced neuro-modulation | |
1Advanced Molecular Imaging Research (AMIR), Medical Physics, Department of Radiology, University Medical Center Freiburg, Freiburg, Germany, 2Faculty of Biology, University of Freiburg, Freiburg, Germany, 3Department of Translational Medicine and Neurogenetics, Institute of Genetics and Molecular and Cellular Biology (IGBMC), Illkirch-Graffenstaden, Strasbourg, France, 4Medical Physics, Department of Radiology, University Medical Center Freiburg, Freiburg, Germany, 5Division of Stereotactic and Functional Neurosurgery, Department of Neurosurgery, University Medical Center Freiburg, Freiburg, Germany, 6Experimental Epilepsy Research, Department of Neurosurgery, University Medical Center Freiburg, Freiburg, Germany, 7Department of Biophysics and Nuclear Medicine, University Hospital Strasbourg, Strasbourg, France, 8Laboratory of Engineering, Informatics and Imaging, University of Strasbourg, Strasbourg, France, 9Department of Neuroradiology, University Medical Center Freiburg, Freiburg, Germany |
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Analysis of neuro-functional connectivity derived from rs-fMRI and neuro-structural connectivity derived from DTI/Fiber Tracking might enable researchers to monitor and characterize physiological or drug induced neuro-modulation in the mouse brain. In our study we present a framework for the analysis on healthy mice with erythropoietin (EPO) treatment. Brain regions with pronounced neuro-modulation in histology also showed changes in neuro-functional and neuro-structural data. |
| 1674 | Hemodynamic and neuronal response in rat under Isoflurane-supplemented Medetomidine sedation assessed by simultaneous BOLD fMRI and Ca2+ recordings | |
1Department of Clinical Radiology, University of Muenster, Muenster, Germany |
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fMRI in rodents has become a widely used technique with various applications in preclinical research. In this context, most studies are performed with anesthetized animals. Medetomidine evolves as a frequently used sedative but long term stability is limited -prolonged stability can be achieved by addition of Isoflurane. Several recent fMRI studies have used this combination. We evaluated the effects of this combination of anesthetics using a multimodal setup of BOLD fMRI and Ca2+ recordings. Even small addition of Isoflurane resulted in a significant decrease of neural (Ca2+) and hemodynamic (BOLD) responses to a distinct electrical stimulus. |
| 1675 | Anesthesia-dependent effects on BOLD onset and amplitude assessed by line scanning fMRI with 50 ms temporal resolution | |
1Department of Clinical Radiology, University of Muenster, Muenster, Germany |
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Medetomidine sedation is a common anesthetic regimen for rodent fMRI studies. However, depth and duration of the sedation may prove insufficient for MR imaging. Adding isoflurane is an efficient way to increase depth and duration of sedation. In rats we varied the concentration of additional isoflurane (0 - 1.5 %) and performed 1D line scanning upon electric forepaw stimulation to characterize the effect of increasing isoflurane on amplitude and onset of the BOLD response. While low concentrations did not significantly alter amplitudes or onsets, we found severely reduced amplitudes and delayed onsets for higher concentrations (> 0.7 %) of isoflurane. |
| 1676 | Effect of alfaxalone anesthesia on brain functional connectivity in rhesus monkeys | |
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 |
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Alfaxalone is suggested to be an optimal anesthetic to examine brain injuries in experimental animals. However, little is known about its impact on neural activity in anesthetized subjects. In the present study, adult rhesus monkeys were used to examine its impact on functional connectivity. The results demonstrate that alfaxalone induces significantly reduced functional connectivity in the dominant default-mode network (DMN), inter-hemisphere connectivity in primary somatosensory cortex and caudate compared to isoflurane. The findings reveal that alfaxalone suppress neural activity more dramatically than light isoflurane anesthesia in monkeys, suggesting it is ideal for investigating anatomical and microstructural changes in animal models but not good for evaluating neuronal activity with fMRI. |
| 1677 | Dose-dependent effects of prolonged isoflurane administration on resting cerebral blood flow and functional connectivity: a preliminary study in rhesus monkeys | |
1Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States, 2Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate, Emory University |
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Isoflurane is widely used in biomedical research with the prolonged duration of administration up to several hours. However, the manner in which neurophysiology and functional connectivity are affected by the length of anesthesia remains poorly understood. In the present study, cerebral blood flow (CBF) and default model network (DMN) were examined using arterial spin-labeling perfusion and resting state functional MRI techniques. The functional connectivity in the dominant DMN decreased substantially during 4-hour administration of isoflurane at any given dosage. CBF in most brain regions decreased at the low dose (0.89 %), but did not change markedly when higher doses of isoflurane (1.05 %, 1.19 %) were administrated. The study revealed dose-dependent effects of isoflurane on brain functionality and regional CBF during prolonged anesthesia administration of isoflurane, suggesting those effects should be considered in the experimental design or the interpretation of the outcome of related neuroimaging studies using anesthetized animals or humans. |
| 1678 | Differential effects of anesthetics on mouse brain connectivity and function as probed by resting-state fMRI and [18]FDG-PET | |
1ICube, CNRS, University of Strasbourg, Strasbourg, France, 2INCI, CNRS, University of Strasbourg, Strasbourg, France, 3Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 4Faculty of Biology, University of Freiburg, Freiburg, Germany, 5IPHC, CNRS, University of Strasbourg, Strasbourg, France, 6Engineering Science, Computer Science, and Imaging Laboratory, Integrative Multimodal Imaging in Healthcare, CNRS, University of Strasbourg, Strasbourg, France, Strasbourg, France, 7Department of Biophysics and Nuclear Medicine, University Hospital Strasbourg, Strasbourg, France |
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Mice resting state functional connectivity (FC) studies are highly attractive given the large number of existing murine models of neuropsychiatric disorders. Currently, most of mouse rs-fMRI studies are carried out under anesthesia, to limit motion and animal distress. Yet, anesthetics affect brain FC. Currently, no reliable awake mouse brain FC reference is available. We compared mouse brain rs-fMRI patterns under medetomidine or isoflurane anesthesia and paralleled the experiments with static 18FDG-PET exams, where the tracer biodistributions occurred under isoflurane, medetomidine anesthesia or in conscious state, reflecting the brain glucose metabolism, as indirect measures of neuronal activity. |
| 1679 | Functional and Metabolic Connectivity of the Awake and Anesthetized Brain | |
1Radiology, University of Wisconsin, MADISON, WI, United States, 2Neuroscience, University of Wisconsin, MADISON, WI, United States, 3Psychology, University of Wisconsin, MADISON, WI, United States, 4Psychiatry, University of Wisconsin, MADISON, WI, United States |
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This study evaluated the effect of anesthesia on functional and metabolic brain connectivity, measured with simultaneous PET/MR using an awake monkey model. Results show a profound disruption of functional connectivity, effective connectivity, and novel approaches to metabolic connectivity following the administration of IV ketamine. |
| 1680 | Effect of Repeated Injection of Iodixanol on Rrenal Function in Healthy Wistar Rats by Using Functional MRI | |
1Department of Radiology, First Affiliated Hospital of China Medical University, Liaoning, People's Republic of China, 2GE Healthcare, MR Research China, Beijing, Beijing, People's Republic of China |
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In clinical practice, for complex, recurrent disease, the same patient may need to use contrast agents repeatedly. However, the administration of multiple use of contrast-medium within a short period of time may put patients at risk1 .So, the aim of this work is to examine differences in rats’ potential kidney injury provoked by iodixanol with respect to different intervals and different times. By using fMRI we observed whether repeated intravenous injection of iodixanol at different time intervals could lead to aggravate kidney damage and then find the shortest time interval. Simultaneously, monitoring kidney damage by sNGAL and detecting the cause of renal injury by immunohistochemistry were also performed. |
| Exhibition Hall | Tuesday 8:15 - 10:15 |
| 1681 | Tradeoffs in pushing the spatial resolution of fMRI for the 7 T Human Connectome Project | |
1Center for Imaging of Neurodegenerative Diseases, Veteran Affairs Health Care System, San Francisco, CA, United States, 2Center for Magnetic Resonance Imaging, University of Minnesota, 3Washington University, 4Oxford Centre for Functional MRI of the Brain, Oxford University |
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Here we describe subsequent work by the Human Connectome Project (HCP), taking the initial advancements obtained at 3 T and pushing spatial resolution even further at ultrahigh field strengths. To assess the impact of spatial resolution on the resultant detectability of resting state networks throughout the brain, we compare 7 T data acquired at various isotropic spatial resolutions (2 mm, 1.6 mm, 1.5 mm, 1.25 mm, and 0.9 mm) using the 2 mm 3 T HCP rfMRI data as baseline. 7 T functional networks show enhanced BOLD CNR, resulting in sharper, stronger, and more well defined spatial detail even at the group level. |
| 1682 | Spatial Registration of fMRI Data Using Functional Correlation Tensors | |
1Guangdong Provincial Key Laboratory of Medical Image Processing, School of Biomedical Engineering, Southern Medical University, Guangzhou, People's Republic of China, 2Department of Radiology and BRIC, University of North Carolina, Chapel Hill, NC, United States |
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Inter-subject registration of functional MRI (fMRI) data is a key step for group analysis. Here, we propose a novel registration strategy that considers functional information from both gray matter (GM) and white matter (WM). This is achieved using functional correlation tensors (FCTs), which capture the local correlation of the BOLD signals. Features extracted from both GM and WM functional correlation |
| 1683 | Is resting-state fMRI guided brain target localization for TMS reliable and reproducible? | |
1Brigham and Women's Hospital, Boston, MA, United States, 2Massachusetts General Hospital, Boston, MA, United States |
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Transcranial magnetic stimulation (TMS) is a noninvasive treatment approach for major depressive disorder (MDD). A recently proposed method1 is to stimulate a sub-region in the left dorsolateral prefrontal cortex (DLPFC) that is most anti-correlated with the subgenual cingulate (SGC) as obtained from resting-state functional MRI (rsfMRI). To test the reliability of this approach, we examined 100 data sets from the Human Connectome Project (HCP)5 with each subject scanned 4 times on two different days. We found large variability in the inter-scan rsfMRI-guided target for each subject, which can significantly reduce the efficacy of TMS therapy in MDD. |
| 1684 | The impact of geometric distortion correction on multisite rs-fMRI data | |
1GE Global Research, Munich, Germany, 2Department of Medical Engineering, Technische Universität München, Munich, Germany, 3Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany, 4Department of Informatics, Technische Universität München, Munich, Germany |
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This study addresses the goal of reducing site-variance in the correlation values of multisite rs-fMRI data by correcting for site-specific EPI-related geometric distortions. Three geometric distortion correction methods (B0 fieldmap and image-based unwarping) were applied separately to a calibration dataset consisting of six subjects traveling to three sites. The change of the correlation values and their site-homogeneity was evaluated in dependency of the quantified geometric distortion correction values for six networks and all subjects. It could be shown that the distortion correction had no significant impact on the correlation values and no correlation between the two parameters was found. |
| 1685 | Growing Apart or Growing Together: a Novel “Developing Triple Network” Hypothesis for Baby Connectome Study | |
1Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2Department of Biomedical Engineering and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 3Department of Brain and Cognitive Engineering, Korea University, Seoul, Korea, Republic of |
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For baby connectome study, we propose a “developing triple network” model based on our findings from precious longitudinal infant resting-state fMRI data, which extends previous “triple network model” to 0-2 years old, a pivotal period which we have little knowledge on. Our developmental model provides future study with key information on early functional connectivity. We found medial prefrontal area is growing apart and its long-range FC is growing together at different speeds in the first 2 years. We, for the first time, found a novel early developmental pattern with both local and long-range FC increases at 6-9 months but decreases afterwards, indicating pivotal neural pruning mechanism from system neuroscience view point. |
| 1686 | Radiation-induced Brain Abnormalities: Plasticity, Progression and Outcome Prediction | |
1Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2Department of Brain and Cognitive Engineering, Korea University, Seoul, Korea, Republic of |
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Brain plasticity is fascinating and important to our life. Radiation therapy can cause brain injury which may cover or progress, posing an ideal case to study brain plasticity. We used a rare and unique cohort of nasopharyngeal carcinoma patients with normal-appearing brains to study irradiation injury in its preclinical stage in context of brain functional and structural plasticity. We found an acute increase in local brain activity, followed by its extensive reduction; and significant functional connectivity loss in the default mode network. Such radiosensitive functional alterations were intriguingly found to be plastic. By contrast, a progressive late disrupted integrity of the related white matter was starting to be significant after one year at the far end. Early increased local brain functional activity was able to predict severe later brain necrosis through a bridge of brain connectome. These findings highlight the importance of brain connectomics in translational clinical study. |
| 1687 | Pediatric Brain Functional Parcellation from Birth to 2-Years-Old | |
1Department of Biomedical Engineering and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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Brain functional parcellation has been shown to discern brain functional atlases in adults. In this study, multigraph K-way clustering1 was employed to reveal temporal evaluation of brain funcitonal atlases in 71 healthy children longitudinally scanned at 1/3/6/9/12/18/24 months of age. Results revealed temporal evolution of brain functional networks during the first two years of life. |
| 1688 | Connectome Based Predictive Modeling: Relating Social Measures to Functional Brain Organization | |
1Radiology and Biomedical Imaging, Yale University, Cambridge, MA, United States, 2Interdepartmental Neuroscience Program, Yale University, 3Department of Psychology, Yale University, 4Department of Diagnostic Radiology, Yale School of Medicine, 5Radiology and Biomedical Imaging, Yale University, 6Department of Neurobiology, Yale University, 7Department of Neurosurgery, Yale School of Medicine |
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We examine the relationship between functional brain networks and behaviour in individuals with autism from the Autism-Brain-Imaging-Data-Exchange. We find a difference in attention network strength between groups (autism vs. control) using an a priori defined network for high-attention [1]. In addition, connectome based predictive modeling (CPM) successfully predicted inattention and communication scores. Finally, on a test group of autistic patients (not used in the CPM), we found network strengths to be more similar to individuals used the CPM with autism than controls. Together, these results indicate that connectivity may prove to be a valuable tool in the diagnosis and treatment of autistic individuals. |
| 1689 | Neurofunctional topography of the human hippocampus: Converging data from a series of studies | |
1Psychology, Auburn University, Auburn, AL, United States, 2Psychology, Auburn University, 3Siemens Healthcare, 4Electrical and Computer Engineering, Auburn University |
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The hippocampus, one of the most phylogenetically preserved structures in the human brain, has been a topic of interest to evolution theorists and cognitive neuroscientists alike. Malfunctions in the hippocampus are hallmark features in a number of psychiatric and neurological conditions, further amplifying interest. Little advancement has been made regarding the neurofunctional topography of the structure. We used high-field, high-resolution neuroimaging techniques to demonstrate convergent evidence on a new theory of hippocampal organization. Data from this project are expected to catalyze efforts in neuroscience and medicine to better understand hippocampal functioning and promote the identification of healthy and aberrant signaling. |
| 1690 | Spatio-temporal extent of spontaneous and sensory evoked neural network activity. | |
1Institute for Microscopic Anatomy and Neurobiology, Johannes Gutenberg-University Mainz, Mainz, Germany, 2Department of Clinical Radiology, University of Münster, Nordrhein-Westfalen, Germany |
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Preclinical functional Magnetic Resonance Imaging in rodents has become a vital research tool for observing functional network connectivity at rest or during sensory stimulation. There is an ongoing debate about the differential effects of anesthesia on cortical connectivity, since functional connectivity networks fluctuate depending on global brain state. We analyzed the spontaneous and sensory evoked BOLD signal in rats during different network states induced by Isoflurane and Medetomidine anesthesia, finding them to lead to fundamentally different cortical connectivity. These results are crucial for interpreting rodent studies in the framework of translational resting state research including awake human data. |
| 1691 | Connectivity of the Default Mode Network – Prior and post an oddball paradigm | |
1Institute of Neuroscience and Medicine 4 (INM4), Forschungszentrum Juelich GmbH, Juelich, Germany, 2Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen, Germany, 3JARA – BRAIN – Translational Medicine, Juelich, Germany, 4TRIMAGE-consortium, Juelich, Germany, 5Department of Neurology, RWTH Aachen University, Aachen, Germany, 6Department of Electrical and Computer Systems Engineering, and Monash Biomedical Imaging, School of Psychological Sciences, Monash University, Melbourne, Australia |
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The DMN is shown to be highly active during resting state and is rapidly deactivated during externally directed tasks. However, it is unclear how demanding the task needs to be to switch the DMN out of the resting state mode. Aiming to answer this question we chose a visual oddball paradigm and assessed the functional connectivity of the DMN during resting state in a rest-task-rest design. The oddball paradigm demands very little cognitive resources and therefore we hypothesize that the DMN will not be altered in its connectivity pattern during post task resting state. |
| 1692 | Resting-state Functional Network Connectivity Pattern as a Cognitive Marker for Task Performance | |
1Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX, United States, 2Section on Functional Imaging Methods, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States, 3The Mind Research Network, Albuquerque, NM, United States, 4Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, United States, 5Functional MRI Facility, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, United States |
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Attentional lapses have been shown to be associated with an altered connectivity and activation pattern of the default-mode network. To further our understanding of the relationship between resting-state connectivity pattern and task performance, we analyzed a multitask dataset including four mental tasks (rest, memory, video, and math). We computed whole-brain connectivity patterns using all volumes during rest (rs-FNC), and the dynamic functional network connectivity (dFNC) patterns during tasks with a sliding window method. We compared similarity between the rs-FNC pattern and dFNCs, which was correlated to the task performance and thus might be used as a cognitive biomarker. |
| 1693 | Dependency of the Activations Detected in Resting State Networks on the History of Physical Exercise Activities in Community Dwelling Older Adults | |
1NeuroImaging & Informatics, NCGG, Ohbu, Japan, 2College of Liberal Arts and Sciences, Mie University, Tsu, Japan, 3NeuroImaging & Informatics, National Center for Geriatrics & Gerontology, Ohbu, Japan, 4Faculty of Human Sciences, Kobe Shoin Women's University, Kobe, Japan, 5Department of Radiological Science, Nagoya University Graduate School of Medicine, Nagoya, Japan |
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In order to explore biomarkers to reflect the effects of long-term physical exercise (PE) on the activities in RSNs, the relationship among the history of participation in PE clubs, the activations in RSNs and the physical activity (PA) was investigated. The activation in the ACG was decreased depending on longer history of PE as well as higher PA indicated by IPAQ scales. These findings may reflect less demand for cognitive integration. It was suggested that both recovery and sedation of the activity in the RSNs against the age-related changes in brain activation may be the biomarker in healthy older adults. |
| 1694 | Hybrid high-order resting-state functional connectivity networks for mild cognitive impairment diagnosis | |
1Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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This study proposes a novel approach named “hybrid high-order FC networks” to explore the higher-level interactions among brain regions for improving the diagnosis performance of early mild cognitive impairment. We first construct the low-order network and the topographical similarity-based high-order network. With the two-level FC networks, we propose to construct a new “associated high-order network”, which is formed by estimating the higher-level interactions between the high-order sub-networks and low-order sub-networks. We further devise a multi-kernel learning strategy to integrate the dynamic networks of the three different levels. A high diagnosis accuracy of 91.5 % demonstrates effectiveness of our proposed approach. |
| 1695 | Functional Bold and Functional T1rho Decoupled in Bipolar Disorder | |
1Radiology, University of Iowa, Iowa City, IA, United States, 2Biostatistics, University of Iowa, Iowa City, IA, United States, 3Psychiatry, University of Iowa, Iowa City, IA, United States, 4Electrical and Computer Engineering, University of Iowa, Iowa City, IA, United States |
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Functional T1 relaxation in the rotating frame (fT1ρ) is a new method of functional imaging that is thought to reflect changes in brain metabolism due to pH. FT1ρ may provide a more direct measurement of neuronal activity than the blood-oxygen level dependent (BOLD) contrast that is typically used for functional imaging. Here we applied both methods in order to study brain activation during a flashing checkerboard paradigm in participants with bipolar disorder as compared to controls. Linear mixed effect regression modeling revealed decoupling between the two imaging modalities in bipolar disorder in several brain regions. |
| 1696 | Low-dose radiation disrupts functional brain connectivity during nociceptive heat stimulation in a mouse model | |
1Institute for Pharmacology and Toxicology, Friedrich-Alexander Universität Erlangen-Nuremburg, Erlangen, Germany, 2Department for Radiology, University Hospital der FAU Erlangen-Nuremberg, Erlangen, Germany |
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Due to improved medical techniques such as CT and radiotherapy todays children are more exposed to low-dose radiation than previous generations. However, little is known about the influence of low-dose radiation on the brain’s development. We hypothesize that altered functional connectivity of activated areas during pain processing can serve as a marker for disturbed brain development. In a mouse model we showed that functional connectivity during nociceptive stimulation after P10 irradiation is disrupted in cortical areas that mature postnatal. We could demonstrate that pain processing is influenced by low-dose irradiation which is in concordance with the brain’s developmental state. |
| 1697 | Greater Connectivity Between Cerebellar Vermis and Insular Attention Resting Network in HIV Patients | |
1John A Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI, United States |
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Individuals infected with HIV frequently have HIV-associated neurocognitive disorders (HAND), despite effective plasma viral suppression. Various resting state networks studied with fMRI have been shown to be attenuated in HIV compared to seronegative controls. This study shows an increased connectivity in HIV subjects between the cerebellar vermis and bilateral insulae. Using clinical correlates, we conclude that this increased connectivity may be due to decreased efficiency in functional connectivity in the HIV-infected brain. |
| 1698 | Resting State Brain Networks in Perinatally HIV-infected Adult Youths | |
1Radiological Sciences, UCLA School of Medicine, Los Angeles, CA, United States, 2Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, United States, 3Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, United States, 4Semel Institute for Neuroscience and Human Behavior, UCLA School of Medicine, Los Angeles, CA, United States, 5Radiology, Harbor-UCLA Medical Center, Torrance, CA, United States, 6Infectious disease-Pediatrics, Miller Children's Hospital, Long Beach, CA, United States, 7Pediatrics, UCLA School of Medicine, Los Angeles, CA, United States, 8Pediatrics, Keck School of Medicine of USC, Los Angeles, CA, United States, 9Psychiatry and Biobehavioral Sciences, UCLA School of Medicine, Los Angeles, CA, United States |
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Youths with perinatally infected HIV survive longer with combination antiretroviral therapy, but remain at risk for poor cognitive outcomes. Since changes in cognitive function may be preceded by subtle changes in brain function, resting-state functional magnetic resonance imaging (rs-fMRI) may become useful in evaluating functional connectivity in these youths. We evaluated alterations in brain functional connectivity in eight perinatally HIV-infected youths and eleven healthy controls. Results from this study demonstrate that, compared to normal subjects, the strength of the several networks connectivity including DMN, Dorsal Attention, Lateral Visual, were significantly decreased in several regions among perinatally HIV-infected youth. The detailed mechanisms, implications of these brain activities and networks exhibiting changes will require further investigation. |
| 1699 | Impaired interactions of large-scale networks predict relapse behavior in heroin-dependent individuals | |
1Tangdu Hospital, Fourth Military Medical University, Xi'an, People's Republic of China |
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Coupling of large-scale brain networks may underlie cognitive dysfunction in psychiatric disorders including addiction. However, whether the deficit of interactions among large-scale brain networks is associated with relapse behavior of heroin addiction remains unknown. This is the first neuroimaging study to assess coupling of large-scale networks that predict relapse in heroin addiction. In this study, we utilized a resting-state functional connectivity method of functional magnetic resonance imaging and found that abnormally higher functional connectivity between the SN and DMN, and lower functional connectivity between the left ECN and DMN were associated with the relapse behavior in treated heroin-dependent patients. |
| 1700 | Localization of the epileptogenic neural network by the resting state fMRI in patients with the temporal lobe epilepsy | |
1Human and Animal Physiology, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, 2Radiology Department, Shupyk National Medical Academy of Postgraduate Education, Kyiv, Ukraine |
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Precise localization of the epileptogenic zone and its delineation from |
| 1701 | Higher Thalamocortical Connectivity May Reduce Efficacy of Temporal Resection | |
1Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 2Psychiatry, Vanderbilt University Medical Center, Nashville, TN, United States, 3Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States, 4Neurology, Vanderbilt University Medical Center, Nashville, TN, United States, 5Biomedical Engineering, Vanderbilt University, Nashville, TN, United States |
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Functional connectivity of the thalamus could inform the potential efficacy of temporal resection in temporal lobe epilepsy. Diffusion and functional MRI was collected from 22 patients who underwent surgical treatment for temporal lobe epilepsy. The thalamus was segmented into six subregions based on diffusion tractography to six regions encompassing the entire cortex. Functional connectivity was calculated between each thalamic subregion and cortical region for each patient. Higher functional connectivity between the contralateral temporal-thalamic subregion and the cortex was associated with seizure recurrence after surgery. |
| 1702 | Disrupted Cortical Modulation of Hypothalamus Functioning for Visceral Homeostasis in Patients with Irritable Bowel Syndrome | |
1Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 2Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, 3Gastroenterology, Medical College of Wisconsin, Milwaukee, WI, United States, 4Pediatric Gastroenterology, Medical College of Wisconsin, Milwaukee, WI, United States |
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The hypothalamus plays a critical role in maintaining visceral homeostasis. We evaluated, using functional imaging, hypothalamus functional connectivity in adolescent IBS patients and controls who received rectal distension stimulations. More extensive hypothalamus connectivity was observed in liminal than subliminal condition in controls, but not in IBS patients. Compared with controls, IBS patients showed significantly reduced hypothalamus connectivity in the bilateral prefrontal cortices, supplementary motor and premotor areas, bilateral sensorimotor cortex, and limbic subareas, which are specifically involved in homeostatic regulation. The findings support that reduced cortical and limbic modulations of hypothalamus functioning underlies disrupted visceral homeostasis in IBS patients. |
| 1703 | Patterns of the whole brain default mode network for alcohol addiction among the alcohol preferring rats | |
1Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, People's Republic of China, 2Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuan, People's Republic of China, 3Department of Anesthesiology, Peking University Third Hospital, Beijing, People's Republic of China, 4Insititute of High Energy Physics, Chinese Academy of Sciences, Beijing, People's Republic of China |
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Alcohol preferring and non-preferring rats were trained with two-bottle choice methods. The whole brain default mode network was acquired during different period of addiction training and after alcohol injection. The correlation coefficients among 28 regions were calculated by mean-value of Pearson correlation. The changes of brain connections after alcohol consumption in different stage of alcohol addiction is significant different. Furthermore, some addiction or reward associated regions and new possible areas (NAc, Tu, VTA, IC, Hypo, SNC, Au, DB, Hipp, VLPO, etc.) showed difference during the training. Our findings could provide preliminary functional connection support of neurobiological circuits change. |
| 1704 | Cocaine applied in a “binge paradigm” induces a region-specific and persistent brain circuitry modulation. | |
1Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium, 2Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland |
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Our pre-clinical rodent study showed an increased Functional Connectivity at the level of the striatum and the cingulate cortex induced by cocaine injection. The effect was detectable 4 hours after administering cocaine and sustained for 24h. |
| 1705 | Resting state fMRI in Patients Infected with Hepatitis C Virus | |
1Research Department, Sidra Medical and Research Center, Doha, Qatar, 2Department of Medicine, King George Medical University, Lucknow, India, 3Department of Radiology and Imaging, Fortis Memorial Research Institute, India, 4Department of Gastroenterology, Sanjay Gandhi Post graduate Institute of Medical Science, India, 5Department of Radiology, Sidra Medical and Research Center, Doha, Qatar |
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Current study measured the amplitude of low-frequency fluctuations (ALFF) and insular functional connectivity (FC) in Hepatitis C virus patients and compared with age and gender matched control using RESTplus software. HCV patients showed significantly reduced ALFF in the right insula. The right insular FC strength was lower in patients than control. Neuropsychological test scores were significantly lower in HCV patients. Changes in ALFF and FC provide new evidences of altered neuronal activity in HCV patients. |
| 1706 | Resting state fMRI in Migraine | |
1Radiology, University of California San Diego, La Jolla, CA, United States, 2Neurology, Scripps Clinic, La Jolla, CA, United States, 3Psychiatry, University of California San Diego, La Jolla, CA, United States |
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We used resting state fMRI to evaluate changes in functional connectivity during migraine episodes, and the response to treatment. The results provide preliminary evidence for a change in functional connectivity in the DMN during migraine, and for the ability of serotonin agonists to restore resting state connectivity. We also identified key brain regions impacted by migraine and then normalized following sumatriptan. |
| 1707 | Real-time fMRI functional connectivity self-regulation and motor performance | |
1Department of Psychiatry, Faculty of Medicine. Pontificia Universidad Católica de Chile, Santiago, Chile, 2Interdisciplinary Center for Neuroscience, Pontificia Universidad Católica de Chile, Santiago, Chile, 3Laboratory for Brain Machine Interfaces and Neuromodulation, Pontificia Universidad Católica de Chile, Santiago, Chile, 4Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Santiago, Chile, 5Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany, 6Institute for Biological and Medical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, 7Department of Electrical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile |
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Brain-Computer interfaces have been used for the rehabilitation of motor and cognitive functions. They can be used to train voluntary neural activity, leading to behavioral effects depending on the targeted brain areas. The aim of this study was to test the feasibility of achieving volitional control of M1-cerebellum functional connectivity with a real-time fMRI (Rt-fMRI) system and evaluates its influence in motor performance. Nine healthy subjects were trained in a protocol with visual feedback and motor imagery. The results indicate that voluntary self-regulation of cerebellum-M1 connectivity is feasible with Rt-fMRI, but the effects on motor performance need to be further studied. |
| 1708 | Altered Functional Connectivity in Essential Tremor Patients immediately following Thalamotomy using MRI guided Focused Ultrasound | |
1Center for Metabolic Imaging & Therapeutics, Department of Diagnostic Radiology & Nuclear Medicine, University of Maryland Baltimore School of Medicine, Baltimore, MD, United States, 2Department of Diagnostic Radiology & Nuclear Medicine, University of Maryland Baltimore School of Medicine, Baltimore, MD, United States |
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Essential tremor (ET) is a common neurological disorder. It is often characterized by progressive tremor of the arms or hands during voluntary movements. Ablation of the |
| 1709 | Disruption of Functional Connectivity in Neonates with Hypoxic Ischemic Encephalopathy at Term | |
1Center for Metabolic Imaging & Therapeutics, Department of Diagnostic Radiology & Nuclear Medicine, University of Maryland Baltimore School of Medicine, Baltimore, MD, United States, 2Pediatrics, University of Maryland Baltimore School of Medicine, Baltimore, MD, United States |
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Perinatal hypoxic-ischemic encephalopathy (HIE) is one of the most common causes of severe, long-term neurologic deficits in children. Up to 40% of infants with HIE who present minimal to no abnormality on structure MRI may still have manifest neurological deficits in later life. In this study, we hypothesize that functional connectivity (FC) of the brain in infants with HIE at term may be altered and that resting-state functional MRI (rs-fMRI) may provide deeper insights into the altered nature of the brain networks, especially the motor network and the thalamocortical network in infants with HIE. |
| 1710 | Towards specific biomarkers of chronic pain: Modelling behavior readouts of developing pain to resting-state functional connectivity using a developmental trajectory in a mouse model of chronic pain from bone cancer | |
1Inst. for Biomedical Engineering, ETH & University of Zurich, Zurich, Switzerland, 2Neuroscience Center Zurich, Zurich, Switzerland, 3Singapore Bioimaging Consortium, Singapore, Singapore, 4Inst. for Pharmacology & Toxicology, University of Zurich, Zurich, Switzerland |
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We performed longitudinal behavioral readouts of pain and resting-state fMRI in a mouse model of chronic pain from breast cancer derived tibial bone metastases. The developmental trajectory of behavioral readouts was used to model the fMRI response to extract pain-specific functional connectivity changes during development of a chronic pain state. The specificity of these functional readouts was supported through inhibition of osteolytic activity, reducing the nociceptive input. Thereby, characteristic functional changes could be reduced and in some regions prevented. These results emphasize the specificity of the functional readouts for developing chronic pain and could be used to evaluate novel treatments. |
| 1711 | Altered Variability in Functional Connectivity of the Anterior Cingulate Cortex in Patients with Refractory and Nonrefractory Major Depressive Disorders | |
1Radiology Department, West China Second University Hospital of Sichuan University, Chengdu, People's Republic of China, 2Huaxi MR Research Center, HMRRC, West China Hospital, Sichuan University, Chengdu, People's Republic of China, 3State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, People's Republic of China |
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Although substantial efforts have been made to elucidate the neuronal basis of both refractory MDD (rMDD) and nonrefractory MDD (nrMDD), the results are inconsistant. We apply the resting-state dynamic functional connectivity (D-RSFC) to explore the divergence of neuroal basis between rMDD and nrMDD. Our results demonstrated that the D-RSFC method can well reveal the dysfunctional brain networks in the MDD. The prefrontal-limbic circuit is the most stable dysfunctional brain network in both MDD subtypes. Additionally, we speculate that the OFC-sgACC circuit, especially the frontal part of the left OFC-sgACC circuit, might be the biomarker for evaluating treatment response in MDD. |
| 1712 | Increased inter-hemispheric functional connectivity in restless legs syndrome using voxel-mirrored homotopic connectivity | |
1MR Research China, GE Healthcare, Shanghai, People's Republic of China, 2Radiology, Shanghai First People's Hospital, Shanghai, People's Republic of China, 3Neurology, Shanghai First People's Hospital, Shanghai, 4MR Research China, GE Healthcare, Beijing, People's Republic of China |
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This preliminary study used voxel- mirrored homotopic connectivity (VMHC), a novel resting-state fMRI parameter to investigate inter-hemispheric functional activity changes in restless legs syndrome (RLS). Ten RLS patients and ten age- and gender-matched healthy controls were recruited for comparison. The RLS group showed increased VMHC in the amygdala, putamen and insula, as compared to normal controls. Increased VMHC in the insular cortex and putamen might reflect their functions in perception and motor control. Increased VMHC in the amygdalae could be relevant to the disturbed sleep at night, considering its primary role in the processing of memory and emotion. |
| 1713 | Effects of Lithium on resting-state fMRI in HIV-associated neurocognitive disorder | |
1Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, United States, 2Department of Imaging Sciences, University of Rochester Medical Center, Rochester, NY, United States, 3Department of Medicine, Stellenbosch University, South Africa, 4Department of Medicine, University of Cape Town, South Africa, 5Department of Psychiatry and Mental Health, University of Cape Town, South Africa, 6Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States |
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This study firstly tested adjunctive lithium therapy in HIV patients with HAND. We examined the lithium effect using resting-state fMRI, and functional connectivity, amplitude of low-frequency fluctuation(ALFF) and fractional ALFF were calculated. We found significantly decrease of low-frequency oscillation and functional connectivity in lithium-treated group compared to placebo group, while neurocognitive performance was not different between the two groups. |
| 1714 | Altered gray matter cerebral blood flow and its connectivity indicate a potential cognitive dysfunction of chronic subcortical stroke patients | |
1Department of MRI, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China, 2Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, People's Republic of China, 3School of Medical Imaging, Tianjin Medical University, Tianjin, People's Republic of China, 4GE Healthcare MR Research China, Beijing |
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In order to investigate gray matter cerebral blood flow (CBF) and CBF connectivity alterations in chronic stroke patients, 60 patients and 60 controls were recruited to undergo 3D ASL technique. The patients exhibited increased CBFs in contralesional SFG, thalamus and ITG, and decreased CBF in ipsilesional Post_CG. Further analysis showed decreased CBF connectivity in patients in ipsilesional Pre_CG, MFG and Msfg. Importantly, the patients exhibited disconnections between the SFG and MFG, mSFG, Pre_CG. Current results suggest that stroke-induced cognitive dysfunction may be a connectivity disorder from the perspective of CBF connectivity. |
| 1715 | fMRI and spectroscopic characterization of sensory and pain processing in “pain-free” mice | |
1Institute for Biomedical Engineering, ETH and University of Zurich, Zurich, Switzerland, 2Neuroscience Center Zurich, Zurich, Switzerland, 3Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland, 4Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London, United Kingdom |
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FMRI has been widely used to assess changes in brain activity evoked by innocuous and noxious stimuli. However, stimulus-evoked fMRI (se-fMRI) measurements in mice have turned out challenging, and it is still under investigation whether and under which conditions se-fMRI applications in mice can lead to reliable readouts. Generally, se-fMRI could be a useful tool to characterize genetically modified mouse strains, such as mice exhibiting altered nociception. In this study, NaV1.7fl/fl:AdvCre mice were characterized with respect to neural processing of different types of peripheral stimuli and compared to a wildtype control group. Results of behavioral tests are compared to outcomes of fMRI and spectroscopic measurements. |
| 1716 | Phenotyping assay of neuropathic pain models using resting state functional connectivity MRI and Graph theoretical analysis | |
1Laboratory Animal Research Department, Central Institute for Experimental Animals, Kawasaki, Japan, 2Keio University, Tokyo, Japan, 3Brain Science Institute, RIKEN, Saitama, Japan, 4Okinawa Institute of Science and Technology Graduate University (OIST), Japan |
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Resting state functional connectivity MRI was performed with neuropathic pain model mice.The functional network was constructed by temporal correlation analysis at the whole brain level based on the Allen brain atlas. Graph theoretical analysis was conducted to evaluate the feature of constructed networks. Compared with the intact model, degree and eigenvector centrality of neuropathic pain model showed a significant reduction in the primary somatosensory area. The clustering coefficient and local efficiency were significantly increased in the ACA. Significantly higher betweenness centrality was observed in the VPL. These results indicate that amount of information about connection to S1 was decreased. Neuropathic pain disrupt the pain matrix and the pain matrix that includes ACA and VPL may construct the complicated network. Integration of resting state functional connectivity MRI and graph theoretical analysis can evaluate the interactive complex networks of each region, not only existence or non-existence of activation region. |
| 1717 | Reorganization of Rodent Resting-state Functional Networks after mild Traumatic Brain Injury | |
1Translational Imaging Research Center, College of Medicine, Taipei Medical University, Taipei, Taiwan, 2Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, 3Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan, 4Department of Medical Research, Taipei Medical University Hospital, Taipei, Taiwan, 5Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan, 6School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, Taiwan |
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Complex network analysis unraveled the mTBI-related functional reorganization with the disruption of long-distance connections of thalamocortical interactions and enhanced local connectivity segregation in the regions of neocortex and thalamic nuclei. |
| 1718 | Enhanced striatum connectivity is irrelevant to baseline perfusion in major depressive disorder following sertraline treatment | |
1Graduate Institute of Humanities in Medicine, Taipei Medical University, Taipei, Taiwan, 2Brain and Consciousness Research Center, Taipei Medical University, Taipei, Taiwan, 3Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan, 4Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, 5GE Healthcare, Taipei, Taiwan, 6Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan, 7Department of Psychiatry, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan |
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We revisited the sertraline treatment effect on RSFC in drug-naïve MDD patients and evaluated the association between RSFC, ALFF and baseline CBF level. Twenty-four unmedicated MDD subjects were recruited and treated with sertraline for 6 weeks. Results showed negative correlation between HAM-D scores and striatum-MPFC RSFC. However, the therapeutic effect on RSFC was irrelevant to the CBF or ALFF levels, implying better temporal synchronizations from the neural basis. |
| 1719 | Learning Subnetwork Biomarkers via Hypergraph for Classification of Autism Disease | |
1University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2School of Software, Tsinghua University, Beijing, China, 3Department of Computer Science, College of Charleston, Charleston, SC, USA, 4Centre for Studies of Psychological Application, School of Psychology, South China Normal University, Guangzhou, China, 5Biomedical Imaging Research Institute (BIRI), Department of Biomedical Sciences and Imaging, Cedars-Sinai Medical Center, Los Angeles, CA, USA, 6Department of Computer Science and Technology, Nanjing University of Aeronautics and As-tronautics, Nanjing, China |
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Most brain network connectivity models consider correlations between discrete-time series signals that only connect two brain regions. Here we propose a method to explore subnetwork biomarkers that are significantly distinguishable between two clinical cohorts. We construct a hypergraph by exhaustively inspecting all possible subnetworks for all subjects. The objective function of hypergraph learning is to jointly optimize the weights for all hyperedges. We deploy our method to find high order childhood autism biomarkers from rs-fMRI images. Promising results have been obtained from comprehensive evaluation on the discriminative power in diagnosis of Autism. |
| 1720 | Relationship between static and dynamic brain functional connectivity in autism spectrum disorders | |
1CIMeC, Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy, 2Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, Istituto Italiano di Tecnologia, Rovereto, Italy, 3Department of Computer Science, University of California, Santa Barbara, Santa Barbara, CA, United States, 4IBM Thomas J. Watson Research Center, Yorktown Heights, NY, United States |
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There is an increased interest in the dynamics of brain functional connectivity, as measured via temporal covariance in resting-state fMRI BOLD signal, and its aberrations in brain disorders. We studied and compared two measures of regional dynamic behaviour, flexibility and variability, across two datasets and show that patients diagnosed with autism spectrum disorder show increased dynamic connectional variability in several brain regions. Furthermore, we establish an interesting association between static and dynamic functional connectivity measures. |
| 1721 | Modulation of Saslience Network Activation after 4 Weeks Verbal Training in Older Adults | |
1NeuroImaging & Informatics, NCGG, Ohbu, Japan, 2Department of Radiological Science, Nagoya University Graduate School of Medicine, Nagoya, Japan, 3Faculty of Human Sciences, Kobe Shoin Women's University, Kobe, Japan, 4NeuroImaging & Informatics, National Center for Geriatrics & Gerontology, Ohbu, Japan, 5Department of Social and Human Environment, Graduate School of Environmental Studies, Nagoya, Japan, 6College of Liberal Arts and Sciences, Mie University, Tsu, Japan |
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The potential of RSN to detect the early change of neuronal networks induced by short-term cognitive intervention was investigated by using a verbal training task to read short sentences aloud everyday for 4 weeks. Twenty community dwelling older adults participated in this study. Activation in the anterior SN was decreased after the training, suggesting optimization of salience processing to integrate visual information and language production. The SN may be potentially a biomarker to firstly reflect the change in response to cognitive interventions in older adults and this finding may be applied to optimize training protocols for each individual. |
| 1722 | Functional Connection Between Brain and Right Upper-arm: A rs-fMRI Study | |
1Department of radiology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan, 2Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, 3Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan, 4Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan |
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This study aimed to explore the functional coupling between the central nervous system and the peripheral nervous system of upper limb. We established a novel imaging-platform to collect the functional images from human brain and upper limb simultaneously. This study disclosed the functional coupling between the peripheral nervous system of upper limb and the brain cortex and demonstrated that peripheral nervous system also involved in the regulation of brain cognitive function and related network changes. |
| 1723 | Network Analysis Revealed Two Distinct Neuronal Circuits Involved in Nociceptive Processing within the Rat Brain after Ablation of TRPV1-Expressing Peripheral Neurons | |
1Institute of Pharmacology and Toxicology, University of Erlangen-Nuremberg, Erlangen, Germany |
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Pain is a vital danger signal, as it prevents the body from suffering burns by hot items. Using BOLD-fMRI, we evaluated the rat's brain response to increasing thermal stimuli to detect which brain structures are involved especially in the processing of nociceptive heat. Therefore, we eradicated selectively the nociceptive-specific TRPV1-expressing neurons via Resiniferatoxin-induced excitotoxicity. This missing nociceptive input from the periphery resulted in a widespread suppression of brain activity in most brain structures except some parts of the brainstem. Graphtheoretical network analysis revealed two distinct circuits of brain structures involved in the processing of noxious temperatures above 48°C. |
| 1724 | Interrogating neurotransmitter systems using resting-state fMRI | |
1Singapore BioImaging Consortium, Agency for Science, Research and Technology, Singapore, Singapore, 2Psychiatric Hospital, University of Zurich, Switzerland, 3Institue for Biomedical Engineering, University and ETH Zürich, Switzerland, 4Institute of Pharmacology and Toxicology, University of Zurich, Switzerland |
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We assessed functional connectivity (FC) in the mouse brain following psilocybin administration. Conventional analysis using dual regression and reference spatial maps derived from independent component decomposition identified a decrease in FC within the ventral striatum network in animals administered with psilocybin relative to vehicle. Dopamine D1 and serotonin 5HT2a receptor gene expression as well as projection maps from the ventral tegmental area and dorsal raphe nuclei obtained from the Allen Brain Institute database were used as spatial references in a secondary dual regression analysis to disentangle the contribution of dopamine and serotonin systems to whole-brain functional connectivity changes. |
| 1725 | Thalamocortical neural responses to whole body heat exposure: A resting-State Functional MRI study | |
1Jinan Military General Hospital, Jinan, People's Republic of China, 2GE Healthcare China |
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In this study, we replicated previous findings about spatially distinct thalamic correlations with cortical regions of interest. Using bi-directional functional analysis, we firstly clarified cortical-subcortical activity during hyperthermic condition by thalamocortical functional connectivity. Specifically, we found weakening connectivity of cortical fronto-polar/anterior cingulate cortex and prefrontal areas with the corresponding thalamic nuclei. On the contrary, the motor/premotor and somatosensory cortical subdivisions showed increased connectivity with thalamic nuclei. The thalamic pulvinar showed reduced connectivity with bilateral superior and middle temporal pole, but increased connectivity with bilateral middle and inferior temporal gyrus. |
| 1726 | Use of Simultaneous Multi-Slice Imaging to Assess Dynamic Connectivity During a Self-Paced Finger Tap Task | |
1School of Physics, University of Nottingham, Nottingham, United Kingdom |
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Previous fMRI studies have demonstrated a number of functional networks in the brain. The introduction of simultaneous multi-slice (SMS)-imaging has allowed a larger volume coverage of the brain to be acquired with a shorter repetition time (TR), increasing temporal resolution so that dynamic connectivity (DC) measures are more achievable. Here, we use sub-second SMS-imaging to assess DC in sensorimotor networks during a self-paced finger tap experiment, and demonstrate changes in DC during individual button presses. |
| 1727 | Relationship between GABA and glutamate and inter- and intra-regional intrinsic connectivity as measured by resting-state fMRI | |
1Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Nottingham, United Kingdom, 2Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, 3Department of Radiotherapy and Radiation Oncology, OncoRay National Center for Radiation Research in Oncology, Dresden, Germany, 4Departments of Psychiatry and Medical Biophysics & Robarts Research Institute, Western University, London, ON, Canada, 5Lawson Health Research Institute, London, ON |
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Associations between GABAergic and glutamatergic systems and measures of brain connectivity have been reported previously. However, there is currently no evidence for associations between these systems and local connectivity measures, limiting our understanding of inhibitory/excitatory balance and connectivity across differing spatial ranges. We demonstrated that only regional connectivity and spontaneous activity, but not long-range connectivity, were associated with GABA and GABA/Glx ratio in the ACC. We suggest that this correlation between measures of intra-regional connectivity and GABA in the ACC may be driven by interneuron activity. Further, associations between neurotransmitter pools and inter-regional connectivity may be region/network and context-specific. |
| 1728 | The intrinsic functional mechanism for olfactory-visual association in the human brain as quantified by fMRI | |
1Radiology, Penn State University, Hershey, PA, United States, 2Radiology, Nanjing University Medical School, Nanjing, People's Republic of China |
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The purpose of this study was to elucidate the reciprocal effect of olfactory-visual associations on olfactory and visual processing in the human brain using fMRI. Young, cognitively healthy participants underwent 3 separate olfactory-visual association paradigms, including either neutral, semantically congruent, or semantically incongruent visual cues. The data revealed significant olfactory activation in the POC and visual areas in response to visual cues, regardless of semantic meaning (neutral, congruent, or incongruent). This reciprocally increased activation in the POC and visual cortex during olfactory-visual cue pairing and subsequent visual cue presentations may suggest an intrinsic functional mechanism for multisensory associative learning. |
| 1729 | Functional magnetic resonance imaging shows network activation from a non-visual light stimulus of deep brain photoreceptors in songbirds | |
1Department of Animal Science, The Pennsylvania State University, University Park, PA, United States, 2Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, United States, 3Huck Institutes of the Life Sciences, The Pennsylvania State University, 4The Neuroscience Program, The Huck Institutes of Life Sciences, 5Interdepartmental Graduate Program in Neuroscience |
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Many avian species go through circannual changes in reproductive organs. Seasonal changes are triggered by non-visual photostimulation, made possible by the existence of nuclei with containing opsin channels. Photoactivation occurs when photosensitive neurons are stimulated, resulting in a cascade of activity in the brain, which initiates gonadal growth. Photorefraction is on a time-scale much longer than an experiment. We used echo planar imaging fMRI with a laser for stimulation and performed independent component analysis on each phase (before, during, and after stimulation). Network activation patterns differ in each phase. |
| Exhibition Hall | Tuesday 13:45 - 15:45 |
| 1730 | Hybrid Modeling for Perfusion Quantification Using Intravoxel Incoherent Motion MRI | |
1Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan, 2Training Program of Leaders for Integrated Medical System, Kyoto University, Kyoto, Japan, 3Neurospin, Gif-sur-Yvette, France |
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IVIM-MRI has been used to estimate perfusion-relative parameters. To increase signal fitting robustness in case of limited SNR, an asymptotic method was recommended. Hence, with the asymptotic method, a threshold b-value should be determined above which flow contamination is deemed negligible. Various diffusion models and a wide range of values for this threshold can be found in the literature. These two effects on quantification were investigated using both computer simulations and human brain data. The results showed that the choice of the model and the threshold critically influenced the quantitative parameters. We proposed a hybrid-modeling method to minimize systematic errors. |
| 1731 | Optimizing the Signal Model for Diffusional Kurtosis Imaging | |
1Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States, 2Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, United States, 3Department of Neurology, Medical University of South Carolina, Charleston, SC, United States, 4Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States |
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A generalized signal model for diffusional kurtosis imaging (DKI) is proposed containing an adjustable parameter that can be optimized to reduced systematic errors in kurtosis estimates. This is illustrated by applying an established tissue model for diffusion in brain to fix the parameter, and numerical simulations are employed to demonstrate the improvement in accuracy relative to kurtosis estimates obtained with the standard DKI signal model. Finally, in vivo brain data is used to compare mean kurtosis estimates obtained with the standard and optimized DKI signal models. |
| 1732 | Diffusion-weighted MR imaging of kidney after administration of 2 types of iodinated contrast medium: a time course study in CIN animal model | |
1Department of Radiology, Peking University First Hospital, Beijing, People's Republic of China |
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DWI is a preeminent noninvasive method to quantify renal function, which may be helpful to understand the pathogenesis of CIN. Our time course study indicates that the iodinated contrast medium can induce some affect to the different zone of kidney. And some differences do exist on the renal transport function after the two kinds of iodinated CM administration. |
| 1733 | Monte-Carlo Analysis of Quantitative Diffusion Measurements Using Motion-Compensated Diffusion Weighting Waveforms | |
1Medical Physics, University of Wisconsin, Madison, Madison, WI, United States, 2Radiology, University of Wisconsin, Madison, Madison, WI, United States, 3Laboratorio de Procesado de Imagen, Universidad de Valladolid, Valladolid, Spain |
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Advanced diffusion MRI acquisition strategies based on motion-compensated diffusion-encoding waveforms have been proposed to reduce the signal voids caused by tissue motion. However, quantitative diffusion measurements obtained from these motion-compensated waveforms may be biased relative to standard monopolar gradient waveforms. This study evaluated the effect of different diffusion encoding gradient waveforms on the signal decay and diffusion measurements, using Monte-Carlo simulations with different microstructures and several reconstruction signal models. The results show substantial bias in observed signal decay and quantitative diffusion measurements in the same microstructure across different gradient waveforms, in the presence of restricted diffusion. |
| 1734 | White Matter Structural Differences among Subjects with Obstructive Sleep Apnea after Persistent CPAP-Treatment: A Non-Gaussian Diffusion MR Study with TBSS | |
1Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States, 2Department of Radiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, People's Republic of China, 3College of Nursing, University of Illinois at Chicago, Chicago, IL, United States, 4Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 5Departments of Radiology, Neurosurgery, and Bioengineering, University of Illinois at Chicago, Chicago, IL, United States |
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Obstructive sleep apnea (OSA) can result in brain white matter (WM) injuries due to the hypoxic exposure. Continuous positive airway pressure (CPAP) is a common method for treating OSA patients. However, it is unclear why some patients respond to the treatment whereas others do not. In this study, we employ a non-Gaussian diffusion MRI method using a continuous-time random-walk (CTRW) model with TBSS analysis to investigate the WM microstructural variations among OSA patients who responded differently to identical CPAP-treatment. Our results have shown that CTRW-related parameters in some WM tracts exhibited significant difference between the responders and non-responders. |
| 1735 | A modified tri-exponential model for multi-b-value diffusion-weighted imaging to detect the strictly diffusion-limited compartment and its initial application in grading and differential diagnosis of gliomas | |
1Department of Neurosurgery, Second Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, People's Republic of China, 2Department of Radiology, Second Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, People's Republic of China, 3Department of Neurology, Second Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, People's Republic of China |
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In this study, we focused on the strictly diffusion-limited compartment with extremely low ADC. Because of the negligible signal attenuation of this compartment, the ADC of this compartment was set as zero. By adding this compartment to the two-compartment model, we presented a modified tri-exponential model. The AICcs of this model were found to be lower than the bi-exponential model and the conventional tri-exponential model, indicating this model is the best. Additionally, the parameters derived from this model, especially the fraction of the strictly diffusion-limited compartment (f0), showed potential clinical value in distinguishing the grade of malignancy of tumors. |
| 1736 | A Fractional Motion Diffusion Model for a Twice-Refocused Spin Echo Pulse Sequence: Analytical Expression and in vivo Demonstration | |
1Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States, 2Departments of Radiology, Neurosurgery, and Bioengineering, University of Illinois at Chicago, Chicago, IL, United States |
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The anomalous diffusion behavior of biological tissue has been investigated by several studies using non-Gaussian diffusion models. Among these, the fractional motion (FM) model has attracted an intense interest by the biophysics community and was recently been introduced to the MR community. The current diffusion signal formulism based on the FM model is limited to a simple Stejskal-Tanner gradient despite the widespread use of the eddy-current-resistant gradient waveform with the twice-refocused spin echo (TRSE) technique. In this study, we theoretically derive a formulism based on the FM diffusion model to characterize anomalous diffusion using a TRSE sequence, and experimentally validate it on healthy human brain in vivo. |
| 1737 | Substantial Error in MD Estimation Introduced by Trace Imaging | |
1Radiology, University of Gothenburg, Goteborg, Sweden, 2Radiation Physics, University of Gothenburg, Sweden, 3Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States |
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Since the single compartment diffusion tensor model does not reflect all contributions in diffusion signal, subsequent implications also may not hold in practice. One of the implications proven wrong here, is that mean diffusivity (MD) maps, which result from diffusion measurements along three orthogonal directions (trace imaging), are independent of the direction of the applied orthogonal gradient triplet. Simulation results with anisotropic multi-compartment diffusion models and human nerve fiber data confirm that the MD measured by trace imaging, which is typically used for rapid stroke delineation, is substantially dependent on the direction of the applied orthogonal gradient triplet and b-value. |
| 1738 | Translocation of Water Molecules in Tissue | |
1Radiology, University of Washington, Seattle, WA, United States, 2Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, United States |
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Numerical simulations of water molecule translocation are presented. The molecules execute random walks in a 3D ensemble of digital cells with density and size pertinent for biological tissue. The mean net displacements reflect “hindered” or “restricted” translocations for both extra- and intracellular water, characterized by an infinite number of exponentials. The hindrance is very sensitive to the cell membrane permeability, in the range for tissue – and controlled by active cell metabolism. |
| 1739 | The Maastricht Diffusion Toolbox (MDT): Modular, GPU accelerated, dMRI microstructure modeling | |
1Maastricht University, Maastricht, Netherlands, 2Brain Innovation, Maastricht, Netherlands |
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MDT's object oriented modular design allows arbitrary user specification and combinations of dMRI compartment models, diffusion microstructure models, likelihood functions and optimization algorithms. Many diffusion microstructure models are included, and new models can be added simply by adding Python script files. GPU based computations allow for ~60x faster model fitting; e.g. the 81 volume example NODDI dataset can be fitted whole brain in about 40 seconds, which makes MDT ideal for population studies. MDT can be extended to other modalities and models such as quantitative MRI. The software is open source and freely available at https://github.com/cbclab. |
| 1740 | Simulating measurements of diffusion across the cell membrane with DEXSY and FEXSY | |
1Centre for Advanced Biomedical Imaging, Division of Medicine, UCL, London, United Kingdom, 2Microstructure Imaging Group, Centre for Medical Image Computing, UCL, London, United Kingdom, 3Sir Francis CRICK Institute |
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Here, we use numerical simulations to demonstrate the feasibility of measuring diffusion exchange across the cell membrane using DEXSY (Diffusion Exchange spectroscopy) and compare it with FEXSY (Filter Exchange Spectroscopy). Simulations were carried out using the CAMINO platform, for a range of permeabilities, in a substrate chosen to model nerve tissue. The results of these simulations suggest that both DEXSY and FEXSY are capable of measuring diffusion exchange, over a physiologically meaningful range of permeabilities, and an extended range of permeabilities (0.365 to 2.008 µm/s). These results demonstrate the potential for these techniques to be used to differentiate pathology from normal tissue. |
| 1741 | Deconvolution based approaches for the simultaneous quantification of IVIM, Free Water and non-Gaussian behavior in Diffusion MRI. | |
1Department of Information Engineering, University of Padova, Padova, Italy, 2Neuroimaging Lab, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini (LC), Italy, 3Radiology Department, University Medical Center Utrecht, Utrecht, Netherlands |
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The in-vivo Diffusion MRI (dMRI) signal does not generally arise from a single diffusion process but from the sum of multiples. In this study we investigated a deconvolution approach to simultaneously estimate non-Gaussian diffusion, free water (FW), IVIM and tissue fractions. We analyzed the brain data of a subject acquired with 60 different b-values with four deconvolution based approaches, and compared their results in terms of identified components. The four approaches provided consistent results, with the IVIM compartment being the most similar component across the four methods. Reliable quantification of multiple compartments, including membrane restrictions, is feasible with regularized approaches. |
| 1742 | White matter biomarkers from fast protocols using axially symmetric diffusion kurtosis imaging | |
1CFIN/MINDLab at the Department of Clinical Medicine, 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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White matter tract integrity (WMTI) can be used to characterize tissue microstructure in areas with strongly aligned fiber bundles. Several WMTI biomarkers have now been validated against microscopy and provided promising results in studies of brain development, aging, and brain disorders. In clinical settings, however, the diffusion kurtosis imaging (DKI) protocol utilized as part of WMTI imaging may be prohibitively long. Consequently, the diagnostic value of the WMTI parameters is mostly explored in dedicated animal studies and clinical studies of slowly progressing diseases. Here, we evaluate WMTI based on recently introduced axisymmetric DKI which has lower data demand than conventional DKI. |
| 1743 | Inferring cell morphology in the heart with a compartment model of diffusion MRI | |
1Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom |
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We propose a three-compartment model to perform cytometry in cardiac diffusion MRI. Our approach adapts the VERDICT model to account for the anisotropic geometry of cardiomyocytes. The model was fit to data from ex-vivo mouse heart imaged with multiple diffusion times, diffusion directions, and q-shells. The model yields realistic volume fractions (intracellular/extracellular/vascular = 68/16/16%) and cell radii (7-9.5 μm). The parameters derived could aid quantitative characterisation of cardiomyopathies including hypertrophy and fibrosis. |
| 1744 | A novel diffusion compartment imaging (DCI) model that captures the asymmetry of WM microstructure heterogeneity | |
1Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States, 2ICTEAM, Universite catholique de Louvain, Louvain-La-Neuve, Belgium, 3Boston Children's Hospital, Harvard Medical School, Boston, MA, United States |
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The DIAMOND diffusion compartment imaging (DCI) model has been recently proposed to model the 3-D diffusivity of each compartment with a statistical distribution of diffusion tensors. This enabled the assessment of compartment-specific diffusion characteristics while also capturing the intra-compartment heterogeneity. The approach, however, could only describe symmetric heterogeneity, while tissue heterogeneity likely differs along and perpendicular to the fascicles' orientation. In this work we propose a new statistical distribution model able to capture the asymmetric nature of tissue heterogeneity. We demonstrate that it captures different axial and radial heterogeneities in presence of dispersion and investigate results with in vivo data. |
| 1745 | The Impact of Edema and Crossing Fibers on Diffusion MRI: ODF vs. DBSI | |
1Chemistry, Washington University, St. Louis, MO, United States, 2Biology, Juniata College, Huntingdon, PA, United States, 3Center for Neuroimaging, Indiana University, Indianapolis, IN, United States, 4Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, United States, 5Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States, 6Neurosciences, Medical University of South Carolina, Charleston, SC, United States, 7Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States, 8Biomedical Engineering, Washington University, St. Louis, MO, United States, 9Radiology, Washington University, St. Louis, MO, United States, 10Hope Center for Neurological Disorder, Washington University, St. Louis, MO, United States |
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We quantitatively examined the effect of fiber crossing and edema on DTI metrics employing phantoms made of mouse trigeminal nerves and agarose gel. Edema mimicked by gel coating significantly impaired the accuracy of estimated crossing angles using the diffusion orientation distribution function. Diffusion basis spectrum imaging (DBSI) was able to estimate crossing angles in the presence of edema and recover individual nerve baseline diffusivity. |
| 1746 | Empirical reproducibility of clinically feasible ensemble average propagator imaging | |
1Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 2Computer Science, Vanderbilt University |
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In this study, we measure the reproducibility of metrics derived from the ensemble averaged propagator (EAP) estimated using the 3D-SHORE technique using a clinically feasible high angular resolution diffusion dataset repeated 11 times on a single subject. We find very low reproducibility in measures of microstructural restriction (including the mean-squared displacement and return to origin probability) as well as measures of the orientation distribution function (including peaks of the ODF). This study highlights the limitations of using advanced models with empirical data, particularly in the low-SNR regime. |
| 1747 | Reconstruction of fetal diffusion MRI using a spherical harmonic model | |
1Division of Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom, 2École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3Health Services & Population Research, King's College London, London, United Kingdom |
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We present a novel method for reconstruction of fetal dMRI based on spherical harmonic model that includes motion correction, distortion correction and super-resolution reconstruction. We show that all these steps are important for producing good quality results. Our method will facilitate investigations into brain white-matter development in utero. |
| 1748 | Monoexponential, Biexponential, and Stretched exponential Diffusion-weighted Imaging Models: Quantitative Biomarkers for Differentiating Renal Clear Cell Carcinoma and Minimal Fat Angiomyolipoma | |
1Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wu Han, People's Republic of China |
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Compared to monoexponential DWI model, biexponential and stretched exponential DWI models are feasible and useful in the noninvasive tissue characterization of renal tumors. Water molecular diffusion heterogeneity index (α) and Dt may provide additional information and could lead to improved differentiation with better sensitivity and specificity in differencing MFAML from ccRCC compared with mean ADC, Dp, fp, and DDC values in clinical setting. |
| 1749 | Preliminary Investigation on NODDI for Studying Spinal Cord Microstructure of Postoperative CSM Patients | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, Beijing, People's Republic of China, 2Department of Surgery, Beijing Jishuitan Hospital, Beijing, China, Beijing, People's Republic of China, 3Department of Radiology, Beijing Jishuitan Hospital, Beijing, China |
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In this study, the neurite orientation dispersion and density imaging (NODDI) was used to investigate the spinal cord microstructure for postoperative CSM patients. MRI data were acquired on eleven patients with a long time after surgery. The value of the calculated parameters (OD, Viso and Vic) were preliminarily evaluated. Statistical results show that OD of grey matter is lower at the stenotic level than the normal level, and Viso in both grey and white matter is higher. To the best of our knowledge, this is the first time that the application of NODDI in the spinal cord disease was reported. |
| 1750 | Exploring ex vivo brainstem complex pathways with diffusion microstructure at 11.7T | |
1Center of NeuroImaging Research - 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, 3AP-HP, Hôpital de la Pitié-Salpêtrière, Department of Neurosurgery, Paris, France, 4AP-HP, Hôpital de la Pitié-Salpêtrière, Department of Neurology, Paris, France |
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We performed multi-shell 3D segmented EPI on a post mortem macaque brain at 11.7T (resolution 200 μm iso, 120 directions) and evaluated NODDI as a tool to accurately extract brainstem pathways. We showed that the orientation dispersion map can help in segmenting ROIs used for tractography. Microstructure information opens promising perspectives for the exploration of the brainstem complex organization ex vivo in human and non-human primate. |
| 1751 | Introducing axonal myelination in connectomics: a preliminary analysis of g-ratio distribution in healthy subjects | |
1University of Rome "Roma Tre", Rome, Italy, 2Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy, 3Clinical Imaging Sciences Centre, University of Sussex, Brighton, United Kingdom |
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We estimated the g-ratio (i.e., the ratio of the inner and the outer diameters of myelinated axons) in-vivo in two different datasets of healthy subjects using diffusion and magnetization data. We used this measure to characterize the organization of the structural connectome and compared it to the information obtained by the streamlines reconstructed using tractography. The g-ratio significantly differentiated hub-related aspects of the connections and subcortico-cortical organization. These preliminary results showed that this measure could provide complementary information to the connectome structure. |
| 1752 | Population averaged ferret brain templates for in-vivo and ex-vivo anatomical and diffusion tensor MRI | |
1Quantitative Medical Imaging Section, NIBIB, NIH, Bethesda, MD, United States, 2SQITS/NICHD, NIH, Bethesda, MD, United States, 3Henry M. Jackson Foundation, Bethesda, MD, United States, 4APG, Uniformed Services University of the Health Sciences, Bethesda, MD, United States |
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In-vivo and Ex-vivo anatomical MRI and DTI templates were generated for the ferret brain along with region of interest segmentation masks based on known ferret neuroanatomy. Templates were built from multiple ferret brain images for each modality using advanced template building tools including symmetric normalization transformation for structural templates and Diffeomorphic Registration for Tensor Accurate AlignMent of Anatomical Structures (DRTAMAS) for DTI templates. The resulting templates are made available on an interactive web site (mriferretatlas.nichd.nih.gov). |
| 1753
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In-vivo whole-brain Neurite Orientation Dispersion and Density Imaging at sub-millimeter scale using gSlider-SMS | |
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital. Department of Radiology, Charlestown, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3Department of Computer Science & Centre for Medical Image Computing, University College London, United Kingdom |
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We demonstrate the feasibility of applying microstructural models of diffusion to sub-millimeter isotropic resolution whole brain images in-vivo. The NODDI model was successfully fitted to a 700µm DWI dataset acquired using the generalized SLIce Dithered Enhanced Resolution Simultaneous MultiSlice (gSlider-SMS) acquisition1. We demonstrate the ability to map finer-scale structures using this high-resolution data when compared to traditional multi-shell 2 mm isotropic acquisition. |
| 1754 | Cerebellar connectivity influences brain network topology | |
1Department of Physics, University of Pavia, Pavia, Italy, 2Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy, 3Department of Physics, University of Milan, Milan, Italy, 4Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy, 5Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, Italy, 6Brain MRI 3T Mondino Research Center, C. Mondino National Neurological Institute, Pavia, Italy, 7Neuroradiology Unit, C. Mondino National Neurological Institute, Pavia, Italy, 8Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom |
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Graph theory based approaches applied to diffusion weighted MRI data have been used for understanding cerebral processing at whole-brain scale. Nevertheless, a few studies have considered including the connectivity with the cerebellum. In this work, the cerebellar role in the whole-brain connectomic was investigated by combining automatic tools and a priori information about cerebellar connections. We assert that it is important to incorporate the knowledge that cerebro-cerebellar connections are all contralateral. Moreover, our findings demonstrate that network topology is highly influenced by the presence or the absence of the cerebellum suggesting that it plays a key role in brain processing. |
| 1755 | Comparison of between-subject and single-subject between-session variability in in vivo DKI brain studies | |
1Forschungszentrum Jülich GmbH, Institute of Neuroscience and Medicine - 4, Juelich, Germany, 2JARA, RWTH Aachen University, Department of Neurology, Faculty of Medicine, Aachen, Germany, 3Georgian Technical University, Department of Physics, Tbilisi, Georgia |
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The knowledge of |
| 1756 | MR imaging of the cervical spinal cord in patients with spinal muscular atrophy and healthy controls | |
1Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Department of Forensic Medicine and Comparative Medicine Lab, Aarhus University, Aarhus, Denmark, 3Department of Neurology, University Medical Center Utrecht, Utrecht, Netherlands, 4Department of Radiotherapy, Cancer Center, University Medical Center Utrecht, Utrecht, Netherlands, 5Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands |
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We studied the architecture and diffusion characteristics in the cervical spine and nerves in spinal muscular atrophic (SMA) patients and healthy controls. We showed the asymmetrical architectural configuration of the cervical nerves in SMA patients. We computed diffusion values of which the mean, axial, and radial diffusivity were lower in the SMA patients than in healthy controls which are in accordance with the clinical symptoms of these patients. Diffusion values of the cervical spine (grey, white and the whole myelum) showed no differences. |
| 1757 | T2 relaxation rates of the fast and slow bi-exponential diffusion components in the in vivo corpus callosum | |
1Massachusetts General Hospital, Charlestown, MA, United States, 2Harvard-MIT Division of Health Sciences and Technology, MIT, Cambridge, MA, United States |
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Bi-exponential diffusion model is widely used to fit for non-Gaussian diffusion. T2 relaxation rates differ between structural compartments, which may bias the results of fits to microstructure models. We incorporate T2 relaxation into the bi-exponential model and leveraged the Gmax = 300mT/m gradient strength of the Connectome scanner to study the apparent T2 times of the two diffusion components. A longer T2 was found for the fast diffusion component when the model allows for different T2 times, but both multiple T2s and single T2 models seem to fit to the data fairly well. The added T2 parameter affects volume fraction more than diffusivity estimates. |
| 1758 | Determining how varying the number of gradients measurements affects fitted surface to volume ratios in tube samples using oscillating spin echo gradients | |
1Physics and Astronomy, University of Manitoba, Winnipeg, MB, Canada, 2Radiology, University of Manitoba, 3Physics, University of Winnipeg, Winnipeg, MB, Canada |
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There is an increasing drive to use diffusion spectroscopy to infer the sizes of structures in samples. Here, we use apodised cosine gradient spin echo sequences (OGSE) to infer the surface to volume ratio of a collection of packed capillary tubes. Aiming to reduce imaging times, this study examines how the number of gradients affects the accuracy and precision of the fitted parameters. We found that collecting OGSE data with two b-values may be sufficient to infer information about small structures, especially if higher gradients strengths are used. |
| 1759 | Determining surface to volume ratios in capillary tube samples using oscillating gradient spin echo sequences | |
1Physics and Astronomy, University of Manitoba, Winnipeg, MB, Canada, 2Radiology, University of Manitoba, 3Physics, University of Winnipeg, Winnipeg, MB, Canada |
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There is an increasing drive to use diffusion spectroscopy to infer the sizes of structures in samples. Most methods use pulsed gradient spin echo sequences which cannot provide short enough diffusion times to probe very small structures. Instead, we use oscillating gradient spin echo sequences (OGSE) to probe the short-time regime allowing for small structures to be measured. Here we use the apodised cosine OGSE to infer the surface to volume ratio of a collection of packed capillary tubes, and use it approximate the tube diameters. |
| 1760 | Translating AxCaliber on a clinical system : 600mT/m versus optimized 80mT/m protocol | |
1Polytechnique Montreal, Montreal, QC, Canada, 2Ecole Centrale de Nantes, Nantes, France, 3A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 4Montreal Heart Institute, Montreal, QC, Canada, 5Functional Neuroimaging Unit, CRIUGM, Universite de Montreal, Montreal, QC, Canada |
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Most model-based diffusion metrics (AxCaliber metrics) have been shown to be less stable and more biased on clinical systems due to the limited gradient strength (40-80mT/m versus >300mT/m on preclinical scanners). In this work we wanted to (i) find the best AxCaliber protocol at 80mT/m and (ii) quantify the bias in the estimated metrics. For these aims, we first optimized an 80mT/m AxCaliber protocol using simulations, then compared experimentally (on an ex vivo cat spinal cord) a 600mT/m protocol versus the optimized 80mT/m protocol. Using the 600mT/m maps as a ground truth, our results show that even though axon diameter cannot be estimated robustly, the fraction of restricted water can be measured accurately (<3% error) and precisely (r2 >0.76) on clinical systems. The short duration of the optimized protocol opens the way to the use of reliable model-based diffusion MRI metrics on a clinical system, metrics that would be particularly useful to measure the degree of myelination through the fiber g-ratio. |
| 1761 | Multi-Spherical Diffusion MRI: An in-vivo Test-Retest Study of Time-Dependent q-space Indices | |
1Universite Cote d'Azur, Inria, France, Sophia Antipolis, France, 2CENIR, Institut du Cerveau et de la Moelle epineere, Paris, France |
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Effective representation of the diffusion signal's dependence on diffusion time is a sought-after challenge in diffusion MRI (dMRI). As a solution, we recently proposed Multi-Spherical Diffusion MRI (MS-dMRI) to represent the dMRI signal in this four-dimensional space - varying over gradient strength, direction and diffusion time. Our representation allows for the estimation of time-dependent q-space features, providing unique insights on the tissue microstructure. In the study, we assess test-retest reproducibility of these indices in three C57Bl6 wild-type mice. We find that due to our effective regularization methodology during signal fitting, these time-dependent features can be estimated reliably without overfitting the data. |
| 1762 | Value of MR DWI with different mathmatical models in the differential diagnosis liver neoplasms | |
1The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China |
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To investigate the utility value of monoexponential model,biexponential model and diffusion kurtosis model diffusion weighted imaging in diagnosis of liver neoplasms. |
| 1763 | Accelerated Diffusion-weighted 129Xe MRI Morphometry of Emphysema in COPD and Alpha-1 Antitrypsin Deficiency Patients | |
1Robarts Research Institute, London, ON, Canada, 2Division of Respirology, University of Western Ontario, London, ON, Canada |
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In this proof-of-concept evaluation, we evaluated 129Xe MRI ADC/morphometry estimates using two different acceleration factors (AF) in a small group of never-smokers, COPD ex-smokers with emphysema and Alpha-1 Antitrypsin Deficiency patients. Such estimates were obtained for three different cases: fully sampled k-space; 50% under-sampling in the phase-encoding direction, AF=2; and 66% undersampling, AF=3. The results of this study showed that the difference in ADC/morphometry estimates from fully sampled and under-sampled k-space were similar to that observed with accelerated 3He multi-b diffusion-weighted MRI in healthy subjects. These differences increase however, with increasing emphysema severity, which requires further investigation. |
| 1764 | Can fast diffusion kurtosis imaging be quantitative in the brain? | |
1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, 2Radiology, Cathay General Hospital, Taipei, Taiwan, 3Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan, 4Graduate Institute of Oncology, National Taiwan University, Taipei, Taiwan, 5Graduate Institute of Clinical Medicine, National Taiwan University, Taipei, Taiwan |
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This study was aimed to investigate the applicability of fast DK imaging for both cerebral gray matter and white matter as a quantitative method. Our experimental data reveal that the dependence of D and K on b-values predominantly exists in areas containing a noticeable amount of cerebrospinal fluid. D is more sensitive to b-value choice than K. With b-values carefully chosen to account for signal-to-noise ratio and model fidelity, fast DK imaging-derived indexes can be quantitative with negligible dependence on b-values in most gray matter and white matter. |
| 1765 | Can we trust structural connectivity? | |
1Computer Science, University of Verona, Verona, Italy, 2Neuroradiology, University Hospital Verona, Verona, Italy |
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Structural connectivity models result from a complex processing chain involving many different steps, each having an impact on the reliability of the final measures. One of the hottest questions in the state-of-the-art is thus “To which extent can we trust the structural connectome?”. In this work, we tackled this issue by focusing on the typical processing pipeline and investigating the impact of the main involved steps. MRTrix CSD-based probabilistic tractography provided the highest stability across subjects and MRTrix reached the largest distance with respect to other softwares in both individual subject and group analysis. |
| 1766 | Diffusion Imaging Reveals White Matter Damage in Ice Hockey Players for Up To Two Months Post-Concussion | |
1University of British Columbia, Vancouver, BC, Canada, 2Pediatrics, University of British Columbia, Vancouver, BC, Canada |
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Traumatic brain injury (TBI) is a leading cause of disability in adults. More sophisticated methods are required in order to understand its underlying pathophysiology and disease progression. Recent interest in an assumption-free DTI analysis, diffusion entropy (DE), has produced some promising results for investigating white matter (WM) and grey matter (GM) microstructure. We set out to test DE against the much more common fractional anisotropy (FA) analysis, in both WM and GM, in 45 hockey players over one season. 11 players sustained a concussion and were scanned at 72 hours, 2 weeks, and 2 months post-injury. |
| 1767 | Fast Linear Fitting of Bi-Exponential Intra-Voxel Incoherent Motion (IVIM) Models | |
1Biosciences, SRI International, Menlo Park, CA, United States, 2Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States, 3Bioscience, SRI International, Menlo Park, CA, United States |
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This work introduces an extremely fast (whole image in ~5s) IVIM fitting procedure based on two sequential linear fits and demonstrates that it is comparable to the more traditional but much slower non-linear fitting. This method is valuable because current fitting methods typically take a significant amount of time, typically from minutes to hours, due to their iterative and non-linear nature. Therefore, this technique can be used as a fitting method alone and also as a way to seed more advanced techniques with accurate starting values. |
| 1768 | Sensitivity of STEAM diffusion MRI to permeability in white matter tissue: a simulation study | |
1Medical Physics, University College London, London, United Kingdom, 2Computer Science, University College London, 3Institute of Neurology, University College London, 4University College London |
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This study investigates the sensitivity of the Stimulated-Echo Acquisition Mode (STEAM) diffusion-weighted signal to permeability quantified with water exchange time $$$\tau_{ex}$$$. In order to do this, Monte Carlo simulations were generated for a range of histologically-plausible $$$\tau_{ex}$$$ and practical scanner acquisition parameters. The results suggest that on the standard clinical scanner (G=70mT/m), STEAM estimates short exchange times (<0.9s), which are characteristic in tissue with myelin damage, while tissue with longer exchange times (>1.5s) is practically indistinguishable from impermeable tissue. The Connectome scanner (G=300mT/m) estimates a much wider range, however needs careful optimisation since the resolution limit is highly dependent on the sequence parameters and SNR’s. |
| 1769 | Diffusion kurtosis metrics as sensitive biomarkers of ageing | |
1Institute of Neuroscience and Medicine 4, Research Centre Jülich, Jülich, Germany, 2Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany, 3JARA - BRAIN - Translational Medicine, RWTH Aachen University, Germany |
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Diffusion tensor imaging is an established tool for the examination of WM connectivity and microstructural changes across the lifespan. More recently, advanced diffusion MRI techniques, such as diffusion kurtosis imaging (DKI), have been shown to provide richer information on tissue microstructure. Thus far, only a few works have been published related to DKI in healthy ageing. In this work, we examined, in a large cohort of subjects, the potential of DKI metrics to unravel microstructural changes due to ageing in different brain regions. |
| 1770 | Stability of co-electrospun brain-mimicking fibers for diffusion MRI | |
1Division of Informatics, Imaging & Data Sciences, School of Health Sciences, The University of Manchester, Manchester, United Kingdom, 2The School of Materials, The University of Manchester, Manchester, United Kingdom, 3Division of Brain Sciences, Imperial College London, London, United Kingdom, 4Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom, 5Bioxydyn Limited, Manchester, United Kingdom, 6Division of Neuroscience & Experimental Psychology, The University of Manchester, United Kingdom |
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This work investigates the stability and reproducibility of brain-mimicking microfiber phantoms. These microfibers were produced by co-electrospinning (co-ES) and characterized by scanning electron microscopy (SEM). Grey matter (GM) and white matter (WM) phantoms were constructed from random and aligned microfibers, respectively. MR data were acquired from these phantoms over a period of 17 months. SEM images reveal that there were some changes in the pore size and porosity of co-ES fibers over a period of 30 months. MR measurements showed variations within the limits expected for intra-scanner variability, thereby confirming the phantom stability over 17 months. |
| 1771 | Abnormal white matter integrity in parkinson’s disease patients with cognitive impairment revealed by tract-based spatial statistics | |
1Department of Radiology, Affiliated Hospital of Guizhou Medical University, Guiyang, China, Guiyang, People's Republic of China |
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Results from recent neuroimaging studies suggest that PD patients with cognitive impairment(PDCI) is associated with abnormal white matter integrity. In this study, we used tract-based spatial statistics (TBSS) method combined with diffusion tensor imaging (DTI) to investigate the microstructural integrity of the white matter in PDCI. Results from TBSS demonstrated that PDCI patients had significantly lower FA than healthy controls in anterior thalamic radiation(atr), corticospinal tract (cst), cingulated gyrus(cg), forceps minor(fi), the right inferior fronto-occipital fasciculus(ifo), inferior longitudinal fasciculus(ilf), superior longitudinal fasciculus(slf) and uncinate fasciculus(uf). There were no white matter integrity changes in PD patients without cognitive dysfunction, And also significantly correlation was found between FA in the right ifo and MoCA scores. |
| 1772 | Changes of non-Gaussian diffusion MRI parameters at different diffusion times in a human breast carcinoma xenograft model | |
1Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan, 2Hakubi Center for Advaned Research, Kyoto University, Kyoto, Japan, 3Graduate Schoolof Medicine, Kyoto University, Kyoto, Japan, 4Research and Educational Unit of Leaders for Integrated Medical System, Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto, Japan, 5Radiation Biology Center, Kyoto University, Kyoto, Japan, 6Department of Systems Sciece, Graduate School of Informatics, Kyoto University, Kyoto, Japan |
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The relationship between diffusion time and diffusion parameters obtained from 7.0T MRI using a human breast carcinoma xenograft model was investigated. There was an increase in K values and decrease in ADCo as well as sADC values in 27.6ms compared to 9.6 ms. Some tumor showed heterogeneous sADC change derived from two different diffusion times. |
| 1773 | Gray matter cellular volume fraction imaging and Alzheimer’s disease | |
1Laboratory of Neuro Imaging, USC Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States |
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Neuronal loss is one of the major outcomes of neurodegenerative diseases such as Alzheimer’s disease (AD) [1,2]. Given the microscopic level of changes associated with neurodegeneration, it is challenging to image with conventional MRI techniques. Microstructural diffusion-weighted MRI is a powerful tool, which has been shown to be sensitive to microscopic brain tissue characteristics [3,4]. However, a relative lack of specificity has impeded its transition to clinic. Here we focus primarily on deriving cell content information in gray matter and apply it to AD. We acquired multi-shell dMRI of two postmortem samples of human hippocampal tissue (one AD and one control) at the same time, with isotropic resolution of 200 mm, using a 16.4T scanner. We modeled signal attenuation based on the observed evidence of faster signal decay of the cellular compartment. Then, we derived the cell volume fraction by fitting the model to the data and compared it within and between our tissues. |
| 1774 | Clinically Feasible Optic Nerve Diffusion Basis Spectrum Imaging at 3T | |
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, 3Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 4Department of Radiology, Washington University, Saint Louis, MO, United States, 5Department of Neurology, Washington University, Saint Louis, MO, United States, 6Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, United States |
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Optic nerve MRI is susceptible to eyeball movement. The relatively long acquisition time of advanced diffusion MRI (dMRI) methods exacerbates the motion sensitivity in optic nerve dMRI and limits the clinical implementation of these methods. In this work, we evaluate a short (less than 2.5 min per eye) single slice coronal optic nerve dMRI acquisition protocol at 3T and propose a 2D optic nerve center searching algorithm customized for such dMRI data. We demonstrate improved optic nerve center contrast after image alignment and the expected benefits of reduced partial volume effects from diffusion basis spectrum imaging (DBSI) analysis. |
| 1775 | Detection of abnormal brain neural circuits in draxin knockout mice using DTI-MRI | |
1Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan, 2Bruker BioSpin K.K., Yokohama, Japan, 3Graduate School of Medical Sciences, Kanazawa University, Ishikawa, Japan |
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The aim of this study is to clarify the role of the axon guidance molecule Draxin in the construction of brain neural circuits by DTI-MRI. MRI was performed on draxin knockout, dra(–), and normal mice both in vivo and ex vivo. The in vivo study of dra(–) revealed that the nerve fibers in the corpus callosum did not intersect with the midline. The ex vivo study of dra(–) demonstrated that the thalamocortical nerve fibers did not extend toward the cerebral neocortex through the internal capsule. We successfully evaluated the influences caused by the Draxin loss with DTI-MRI. |
| 1776 | Characteristic analysis of in vivo and ex vivo rat brains by 7.0 T DTI MR | |
1Department of Radiology, West China Hospital, Chengdu, People's Republic of China |
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Ex vivo diffusion tensor imaging (DTI) are widely used in experimental studies for excellent images. The comparison between in vivo and ex vivo DTI has been conducted without the same scan parameters. We aimed to compare the living and fixed white and gray matters under the same condition and explore the effects of coil and signal average. Diffusivities were significant different between living and fixed brains. Coil and signal average significantly affected the signal-to-noise ratio of ex vivo white and gray matters. The results indicate that fixation and MR conditions should be considered in clinical and experimental DTI studies. |
| Exhibition Hall | Tuesday 13:45 - 15:45 |
| 1777 | Evaluation of the Quality of Eddy-Currents and EPI Distortion Correction for Diffusion MRI: A Dataset for Benchmarking | |
1Quantitative Medical Imaging Section, NIBIB/NIH, Bethesda, MD, United States, 2SQUITS/NICHD/NIH, Bethesda, MD, United States, 3Henry Jackson Foundation, Bethesda, MD, United States, 4NIH MRI Research Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States |
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In recent years, numerous methodologies have been proposed for the correction of motion, eddy-currents and echo planar imaging (EPI) distortions for diffusion MRI data. The typical strategy to assess the quality of these corrections is to compare them to an undistorted image, such as a T1-weighted or T2-weighted structural image, with different quality measures such as outlines, similarity metrics or segmentation overlaps. Even though several of these measures are quantitative, the use of wide range of validation strategies in combination with data with significantly different distortion properties complicates a direct comparison of these techniques. In this work, we propose a quantitative, unbiased and robust strategy to evaluate the performances of these correction techniques and provide a publicly available benchmarking dataset. |
| 1778 | Compressed Sensing to Accelerate Connectomic Histology in the Mouse Brain | |
1Center for In Vivo Microscopy, Department of Radiology, Duke University, Durham, NC, United States |
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We evaluated the utility of compressed sensing (CS) for diffusion tensor (connectomic) histology in the mouse brain at high field (9.4T). We explored the effect of b values, compression factors, and k-space sampling strategies. We were able to achieve compression factors of 4X through judicious choice of k-space sampling patterns. Comparison to a comprehensively acquired data set (full sampling at 43 μm with 120 angles) allowed us to reduce the acquisition time by nearly 30X with minimal loss in the resulting connectome. |
| 1779 | Prediction of outcome in bilateral common carotid artery occlusion (BCCAO) rats by intravoxel incoherent motion (IVIM) analysis at 11.7 Tesla | |
1Department of Neurosurgery, Iwate Medical University, Morioka, Japan, 2WPI Immunology Frontier Research Center, Osaka University, Suita, Japan, 3Center for Information and Neural Networks (CiNet), NICT and Osaka University, Suita, Japan |
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Rats with the bilateral carotid artery occlusion (BCCAO) was often used for assessment of the brain damage caused by chronic cerebral hypoperfusion as a longitudinal ischemic animal model; however, the mortality is high and it has remained unclear what kinds of initial cerebral hemodynamic changes occurred in the brain in the hyperacute phase after BCCAO and whether the changes related with the mortality in rats or not. Intravoxel incoherent motion (IVIM), which is the basic concept of diffusion-weighted imaging (DWI), can non-invasively demonstrate various hemodynamic situations at one time DWI scan with multiple b values. Here, we investigated whether the outcome of BCCAO rats associated with cerebral hemodynamic changes assessed using IVIM- DWI. |
| 1780 | Correction of nonuniform diffusion weighting in DWI using vendor-provided gradient characteristics | |
1Radiology, University of Michigan, Ann Arbor, MI, United States, 2Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, 3GE Global Research, Niskayuna, NY, United States, 4Siemens Healthcare, Malvern, PA, United States, 5Philips Research Laboratories, Hamburg, Germany, 6Radiology and Radiological Science, John Hopkins University School of Medicine, Baltimore, MD, United States |
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System-specific gradient nonlinearity (GNL) causes spatially nonuniform weighting in diffusion weighted imaging (DWI). This leads to systematic bias and variability in derived apparent diffusion coefficient (ADC) maps, diminishing their quantitative utility for multi-site, multi-platform clinical trials. An ADC error correction methodology for three-direction DWI acquisition was developed previously using an empiric system GNL approximation. Here we demonstrate implementation of correction for three clinical scanners using the system-specific gradient-channel fields derived from vendor-provided spherical harmonic tables. Implemented correction substantially improves precision and removes ADC bias for ice-water phantoms. Comparable accuracy and performance is achieved across all gradient platforms. |
| 1781 | Toward Analytic Computation of Fiber-Radial Diffusional Kurtosis by Q-space Data Representation with Radial Basis Functions | |
1Graduate School of Information Sciences, Hiroshima City University, Hiroshima, Japan, 2Hiroshima Heiwa Clinic, Hiroshima, Japan |
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To enhance the robustness of the fiber-radial diffusional kurtosis computation, the signal decay in the Q-space can be averaged among the fiber-radial orientations. By using the radial basis functions with Gaussian basis, it is shown that the fiber-radial signal decay can be represented in a pseudo-analytic form with the Bessel function. By using in-vivo diffusion MRI data, the computation results were presented in comparison with those by diffusion kurtosis tensor of 4th order to prove the effectiveness of the proposed method. |
| 1782 | Directional sensitivity of anomalous diffusion assessed using a tensorial fractional motion model | |
1Center for MRI Research, Peking University, Beijing, People's Republic of China, 2State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, People's Republic of China, 3MR Research China, GE Healthcare, Beijing, People's Republic of China |
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Anisotropic diffusion in the nervous system is most commonly modeled by the apparent diffusion tensor, which is based on normal diffusion theory. However, the departure of the diffusion-induced signal attenuation from the mono-exponential form indicates the existence of anomalous diffusion. The fractional motion (FM) model, which is considered as the appropriate anomalous diffusion theory for biological tissues, has been applied to diffusion MRI. However, the directional sensitivity of the FM model in biological tissues remains elusive. In this study, this issue was addressed via tensor analysis in analogy with the diffusion tensor. |
| 1783 | Solving the free water elimination estimation problem by incorporating T2 relaxation properties | |
1Vision Lab, University of Antwerp, Antwerp, Belgium, 2Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, 3Delft Center for Systems and Control, Delft University of Technology, Delft, Netherlands, 4Department of Radiology, Antwerp University Hospital, Antwerp, Belgium |
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The free water elimination (FWE) model fitting problem is inherently ill-conditioned, leading to the need for solutions that can avoid or deal with these kinds of fitting problems. In this work, we evaluate a model extension to the FWE model that exploits the T2-relaxation properties and subsequently leads to a well-posed fitting problem that can be easily solved using standard estimation techniques. |
| 1784 | Investigating the Effects of Concurrent Magnetic Field Monitoring on High Angular Resolution Diffusion Imaging: Application to Cortical Parcellation | |
1Institute for Biomedical Engineering, ETH Zürich, Zürich, Switzerland, 2Laboratory for Social and Neural Systems Research, University of Zürich, Zürich, Switzerland, 3Department of Cognitive, Perceptual and Brain Sciences, University College London, London, United Kingdom, 4Centre for Medical Image Computing, University College London, London, United Kingdom, 5Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands, 6Psychology Department and Neuroimaging Center, San Diego State University, CA, United States |
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The concurrent field monitoring has been proposed to eliminate image artifacts in diffusion imaging introduced by the long lasting eddy currents from the diffusion-encoding gradients. In this work we investigated the effects of field monitoring system on HARDI and applied the improved HARDI data to cortical parcellation. We showed that the field monitoring improved the HARDI data quality especially in anterior/posterior poles of the brain and air-tissue interfaces. This regional improvement was also clear in the cortical classification results, where the field monitoring improved the accuracy of the V1/V2 by 3%, compared to ~0.5% in the motor strip. |
| 1785 | Predicting patient survival in hepatocellular carcinoma (HCC) from diffusion weighted magnetic resonance imaging (DW-MRI) data using neural networks | |
1Image-Based Biomedical Modeling Group, Technical University of Munich, Munich, Germany, 2Institute of Radiology, Technical University of Munich, Munich, Germany, 3Department of Neurology, Ludwig Maximilian University of Munich |
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In this work we present a method to predict patient survival in hepatocellular carcinoma (HCC). We automatically segment HCC from DW-MRI images using fully convolutional neural networks. In a second step we predict patient survival rates by calculating different features from ADC maps. We calculate Histogram features, Haralick features and propose new features trained by a 3D Convolutional Neural Network (SurvivalNet). Applied to 31 HCC cases, SurvivalNet accomplishes a classification accuracy of 65% at a precision and sensitivity of 64% and 65% when trained using our automatic tumor segmentation in a fully automatic fashion. |
| 1786 | Automatic detection of volumes affected by subvolume movement | |
1The Australian E-Health Research Centre, CSIRO, Brisbane, Australia, 2The University of Queensland, Brisbane, Australia |
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Diffusion-weighted MRI is prone to a number of artefacts, including movement between subvolumes in an interleaved acquisition. Affected volumes need to be identified and dealt with before further processing. We use a registration based approach to identify volumes affected by subvolume motion, and demonstrate that a single metric, calculated from all subjects acquired using the same acquisition protocol, is sufficient to reliably identify such volumes. Importantly, the detection threshold is determined from the data itself, and can be applied to multi-shell data. |
| 1787 | Exploring the potentials and limitations of improved free-water elimination DTI techniques | |
1Cognition and Brain Sciences Unit, MRC, Cambridge, United Kingdom, 2Haukeland University Hospital, Bergen, Norway, 3eScience Institute, The University of Washington, Seattle, WA, United States, 4Departments of Psychiatry and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States |
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Free-water diffusion tensor imaging (fwDTI) was previously proposed to remove CSF partial volume effects of measures based on the diffusion tensor. Nevertheless, this diffusion-weighted technique is still subject to several pitfalls. In this study, an improved algorithm to fit the fwDTI to data acquired with two or more diffusion-weighting gradients is proposed. This algorithm is then used to explore the advantages and limitations of suppressing free-water in synthetic and in vivo diffusion-weighted data. |
| 1788 | Impact of Prior Distribution and Central Tendency Measure on Bayesian IVIM Model Fitting | |
1Department of Radiation Physics, University of Gothenburg, Gothenburg, Sweden |
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Bayesian model fitting has been shown to yield robust estimates of the IVIM parameters. However, various methodological choices have differed between studies, which may have substantial effect on the results. This study investigates the effect that the prior distributions and central tendency measures may have, using both in vivo data and simulations. The results show that the prior distribution can play a significant role at commonly seen signal-to-noise levels. The choice of central tendency measure has less effect on the estimates. However, it may be chosen to emphasize either accuracy or precision. |
| 1789 | Characterization of the ulnar nerve using multislice DTI using a multiband factor of 1, 2, and 3 | |
1Radiology and Imaging, Hospital for Special Surgery, New York, NY, United States, 2GE Global Research, Niskayuna, NY, United States, 3Apps & Workflow, GE Healthcare, New York, NY, United States |
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Multiband (MB) echo planar MR imaging (EPI) excites and refocuses multiple slice locations simultaneously using MB radiofrequency excitation and refocusing pulses that are subsequently un-aliased by exploiting differences in coil sensitivities. In this study, we investigated the feasibility of using MB diffusion tensor (DT) EPI with a multiband factor of 1, 2, and 3 to interrogate the ulnar nerve at different locations in the arm. |
| 1790 | Fractional anisotropy spatial covariance analysis in Parkinson’s disease suggests a disease related degeneration pattern | |
1Radiological Sciences, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, United Kingdom, 2Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, 3Centre for Neurodegeneration and Neuroinflammation, Imperial College London, London, United Kingdom, 4Both authors contributed equally. |
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Parkinson’s disease (PD) is characterised by disrupted functional and structural brain networks. Structural network changes are thought to better reflect progression of the neurodegeneration. To study the pattern of neurodegeneration in Parkinson’s disease (PD), we investigated the correlation pattern of fractional anisotropy (FA) with substantia nigra (SN) using a structural covariance analysis method. We also correlated FA maps with the unified Parkinson's disease rating scale (UPDRS); we found a disruption of SN covariance FA maps in PD compared to controls. Moreover, disease severity was significantly correlated with FA in cerebellar and anterior cingulate cortex (ACC). |
| 1791 | Novel application of the reversed gradient method in Diffusion Weighted-MRI for tumor response assessment in head and neck squamous cell carcinoma patient undergoing radiation therapy. | |
1Medical Physics, Memorial Sloan-Kettering Cancer Center, NEW YORK, NY, United States, 2Department of Radiology, Complutense University, MADRID, Spain, 3Department of Medical Physics and Radiological protection, Galaria - Hospital do Meixoeiro – Complexo Hospitalario Universitario de Vigo, VIGO, Spain, 4Medical Physics, Oncoserv, Santiago de los Caballeros – Dominican Republic, Dominican Republic, 5Department of Radiation Oncology, Galaria - Hospital do Meixoeiro – Complexo Hospitalario Universitario de Vigo, Spain, 6Departments of Medical Physics & Radiology, Memorial Sloan-Kettering Cancer Center, NY, United States |
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Reversed gradient method can reduce geometric distortion leading to |
| 1792 | Age-related effect on white matter changes and lexical retrieval | |
1Center for Cognition and Mind Sciences, National Tsing Hua University, Hsinchu, Taiwan, 2Department of Biomedical Engineering, Mingchuan University, Taiwan, 3Department of Gerontechnology, National Center for Geriatrics and Gerontology, Obu, Japan, 4Swartz Center for Computational Neuroscience, University of California San Diego, San Diego, United States |
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Identifying age-related white matter change is vital to understanding neurodegeneration. With studies focusing mainly on memory, little is known of age-related change in language function. This current study bridges the gap by investigating the relationship between changes of WM integrity and task-based language performance. The behavioural evidence revealed significant different between young and healthy elderly people in phonemic as well as semantic retrieval. Also, TBSS analysis suggest significant difference in white matter volume between the two groups. However, correlation between white matter indices, FA and MD, was not found, indicating that degeneration of language function cannot be account for solely on white matter changes or particular task type. |
| 1793 | Robust mapping of diffusion parameters of the combined IVIM-Kurtosis-model using artificial neural networks in the human brain | |
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany |
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In this work we present an artificial neural network (ANN) approach for the evaluation of the combined IVIM-Kurtosis model and robust mapping of the diffusion parameters in the human brain. Measuring seven healthy subjects the parameter map quality could be improved compared to an ordinary least squares regression by significantly reducing outliers and decreasing the variance while preserving the tissue contrast. An ROI-based analysis additionally showed a better agreement of the mean parameter values with the literature along with a better distinction between white and grey matter for the ANN approach. |
| 1794 | Simulation study for the evaluation of DWI data with the IVIM-Kurtosis model based on artificial neural networks | |
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany |
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In this work we present an evaluation approach based on artificial neural networks (ANN) for fitting the IVIM-Kurtosis model parameters on the basis of simulated DWI data. The ANN approach is compared to an ordinary bounded least squares regression (LSR) in terms of correlation between estimates and ground truth, systematic, statistical and total estimation error. While for D and K high correlations and low errors were found for both LSR and ANN, a significant improvement was observed for f and D* regarding correlation coefficients, precision and the total estimation error when using ANN. |
| 1795 | New approach to improve the reliability of IVIM parameters using computed DWI based on stretched exponential model | |
1Philips Healthcare, Seoul, Korea, Republic of, 2Hanyang University, Seoul, Korea, Republic of, 3Samsung Medical Center, Seoul, Korea, Republic of, 4Philips Healthcare, Tokyo, Japan |
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We propose a new approach to IVIM analysis using computed DWI (cDWI) based on stretched exponential model. IVIM analysis is widely studied clinically to evaluate tissue perfusion and diffusivity using a range of low and high b values. However, signal attenuation curves of different b values are heterogeneous because of biological effects from multiple components and patient’s motion during the acquisition. So we generated cDWI first using stretched exponential model which can better fit for signal attenuation curve and analyse IVIM parametric maps using cDWI. The proposed approach can fit more robustly the IVIM model parameters. |
| 1796 | Longitudinal tissue changes in tumefactive demyelinating lesion associated with the administration of disease modifying drugs: a free water diffusion MRI study. | |
1Trento University, Department of Cognitive Science, Trento, Italy, 2Brigham and Women’s Hospital, Harvard Medical School, 3Section of Neurology, Hospital of Rovereto, 4Section of Neurology, Hospital of Rovereto, APSS, 5Section of Neuroradiology, Mayo Clinic, 6Neuroradiologist, U.O. Radiology |
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It is challenging to diagnostically distinguish tumefactive demyelinating lesions (TDLs) from tumors surrounded by massive edema and mid-line shift such as high grade gliomas. We demonstrate free water diffusion MRI analysis to identify water diffusivity compartments in the lesion, and to monitor effects of medical treatment over time. We believe that free water diffusion analysis can be important adjunct to conventional MR, and adds value by improving our understanding of the histologic components of a lesion, which can help clinical diagnosis and potentially avoid biopsy. |
| 1797 | Multi-Tensor Filtering based on Expectation-Maximization Framework | |
1Computer Science, Université de Sherbrooke, Sherbrooke, QC, Canada, 2Computational Radiology, Harvard Medical School, Boston, MA, United States, 3ICTEAM, Université catholique de Louvain, Louvain-La-Neuve, Belgium |
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In this abstract, we introduce a new multi-tensor regularization and denoising technique based on Expectation-Maximization framework. To reduce filtering blurring effect and preserve sharp edges, we incorporated anisotropic regularization weight to the framework. We also utilize a tensor similarity metric, made from a quaternion representation, to improve the regularization and preserve tensor characteristics. Finally, we evaluate and compare filtering methods using a diffusion MRI synthetic phantom and in-vivo acquisition. |
| 1798 | Cortical Diffusion Analysis of Human Connectome Project Data Identifies Granular Cortices | |
1Department of Electrical Engineering, Stanford University, Stanford, CA, United States, 2Department of Radiology, Stanford University, Stanford, CA, United States, 3The Center for Cognitive and Neurobiological Imaging, Stanford University, Stanford, CA, United States, 4Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States, 5Department of Radiology, Harvard Medical School, Boston, MA, United States |
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We performed whole-brain cortical surface-based analysis of diffusion orientations on 100 subjects from the Human Connectome Project. Correlations between diffusion angles (angles between primary diffusion orientations and cortical surface normals) and cortical thickness and curvature were removed using rank-based linear regression. The resulting diffusion angle maps show radial diffusion orientations in all regions except for a few granular cortices which have predominantly tangential diffusion orientations. Identification of the granular cortices is greatly enhanced in the group-averaged map compared to a single-subject dataset. |
| 1799 | A Bayesian approach for diffusional kurtosis imaging | |
1School of Health Sciences, Fujita Health University, Aichi, Japan, 2Department of Radiology, Nagoya City University Hospital, 3Washimi Orthopedic Surgery, 4Department of Radiology, Fujita Health University Hospital |
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We propose a Bayesian approach for improving the accuracy of diffusional kurtosis imaging in a small number of data acquisitions. Gaussian-approximated prior distributions are made from primary maximum-likelihood estimation (MLE). The approach was tested using a healthy volunteer data in which a part of signals was replaced with simulated glioma signals. Although the approach does not yield further improvement when MLE has a certain degree of accuracy, the approach has effect to reduce large misestimations and did not cause false shrinkage of dispersions that the sample parameters inherently have. The approach reduces the burden of data acquisition. |
| 1800 | Low Rank plus Sparse Decomposition of ODF Distributions: Whole brain Statistical Analysis of Higher Order Diffusion Datasets | |
1Center for Advanced Imaging Innovation and Research (CAI2R), NYU School Of Medicine, New York, NY, United States, 2Center for Biomedical Imaging, Dept of Radiology, NYU School Of Medicine, New York, NY, United States |
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Recent advances in data acquisition make it possible to use |
| 1801 | Robust identification of rich-club organization in weighted and dense structural connectomes | |
1Florey Institute of Neuroscience and Mental Health, Melbourne, Australia |
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Rich-club organizations, characterizing the higher-level topology of the brain network, has been commonly identified from structural connectomes constructed using DTI based on network degrees. This analysis can however be compromised by the following issues: (i) DTI limitations in resolving crossing-fibers; and (ii) the original degree-metric based approach is unsuitable for highly-connected connectomes, because it leads to nodes with indistinguishably high degrees. Importantly, increasing evidence suggests that brain connectomes could be very dense. To address these issues, we propose a robust framework by: (i) applying advanced-tractography to construct connectomes; and (ii) developing a h-degree based method, RICHER, to identify rich-club organization. |
| 1802 | Assessment of Inherent Variation in Diffusion Tensor Measurements with Multi-band EPI in Rhesus Monkeys | |
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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Multi-band EPI technique is becoming prevalent in diffusion MRI because it can reduce the scanning time substantially by simultaneously exciting multiple slices and then decoding signal by parallel MR imaging reconstruction algorithms. However, little is known about its influence on the inherent variations of diffusion measurements with or without multi-band parallel acquisitions. This study compared the variations of the in-vivo diffusion MRI measurement results by multi-band and conventional parallel acquisitions. The results showed that the inherent variations of diffusion MRI measurements can be reduced by multi-band parallel acquisition compared to conventional parallel MRI acquisition. |
| 1803 | Individualized prediction of mild cognitive impairment based on patterns of altered tract integrity over the whole brain using diffusion spectrum imaging | |
1Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan, 2Department of Psychology, National Taiwan University, Taipei, Taiwan, 3Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan, 4Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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In this study, we tested the capability of individualized prediction for mild cognitive impairment (MCI) by using the information of whole brain tract integrity produced by tract-based automatic analysis method. The information was trained to search the tract segments that could most accurately separate the MCI patients and healthy participants. The optimal tract segments were searched with the area under receiver operating characteristic curve of 0.76. These specific segments of white matter tracts could potentially serve as imaging biomarker for predicting patients with MCI. |
| 1804 | Histogram Analysis of Intravoxel Incoherent Motion MR Imaging–Related Parameters in Brain Glioma Grading: A Comparison Between 2D and 3D methods | |
1Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China, 2Guangdong Provincial Key Laboratory of Medical Image Processing, School of Biomedical Engineering, Southern Medical University, Guangzhou, People's Republic of China, 3Philips Healthcare, Guangzhou, China., 4Department of Medical Imaging Center, The Third Affiliated Hospital, Southern Medical University, Guangzhou, People's Republic of China |
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Gliomas are the most common primary neoplasms of the brain, World Health Organization (WHO) clarify it from low grade(LGGs; grade II) to high grade(HGGs; grades III, IV). The objective of this study was to explore which method is the best method with little time consuming and good grading of glioma. |
| 1805 | Preliminary analysis of micro-structural changes in different locations of brain tissue affected by acute ischemic stroke using diffusional kurtosis imaging | |
1Radiology, Xiamen No.2 Hospital, Xiamen, People's Republic of China, 2MR Research China, GE Healthcare, People's Republic of China |
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The performance of diffusion kurtosis imaging (DKI) in the analysis of micro-structural changes of brain tissue affected by acute ischemic stroke was explored. 199 lesions in common affected locations were divided into six groups. The value of DKI-derived indices and their changed percentage relative to normal contralateral ROI were calculated. Multiple comparisons among groups indicated that kurtosis indices (especially MK and Ka) showed better performance compared to diffusion indices (ADC, MD, Da and Dr) in detecting structure changes of brain tissues affected by acute ischemic stroke. |
| 1806 | Rapid Measurement of Perfusion Fraction in Clinical Neuroimaging | |
1Physical Sciences of Imaging in Biomedical Sciences (PSIBS), University of Birmingham, Birmingham, United Kingdom, 2Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom, 3Department of Oncology, Birmingham Children's Hospital, Birmingham, United Kingdom, 4School of Computer Science, University of Birmingham, Birmingham, United Kingdom |
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This study investigated the reliability of using a rapid three b-value diffusion-weighted imaging to determine intravoxel incoherent motion (IVIM) parameters. Grey matter simulations were conducted to assess the bias and reproducibility of the parameters with b-value distributions: b0,300,500,1000, b0,500,1000 and b0,300,1000. The same b-value distributions were assessed with a volunteer cohort. The results showed that the use of two high b-values provided a good estimate of the perfusion fraction, which was further improved by an increase in the SNR level. In conclusion, the measurement of IVIM-f was achievable using a three b-value protocol. |
| 1807 | Minimizing the error in finding peak orientations of fiber ODF in diffusion MRI using Nelder-Mead simplex method | |
1Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, Miaoli, Taiwan, 2The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 3Department of Computer Science and Information Engineering, Chang Gung University, Taoyuan, Taiwan, 4Department of Neurology, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan, 5Institute of neuroscience, National Yang-Ming University, Taipei, Taiwan, 6Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan |
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Discrete mesh search method is commonly used to determine fiber orientations by searching orientations corresponding local maxima of orientation distribution function (ODF). However, this method may produce extra errors relating to the number of sampling points of ODF in fiber orientation estimate. We address this problem and minimize the error of fiber orientation estimate by using Nelder-Mead simplex method. The results from computer simulation and phantom experiment show that Nelder-Mead simplex method gives accurate fiber orientation estimation better than discrete mesh search method with ODF sampling points less than 163,842. |
| 1808 | Application of Weighted Diffusion Subtraction (WDS) to Synovial Sarcomas: Possibility of Visualising Tumor Cellularity | |
1Department of Radiology, Nippon Kokan Hospital, Kawasaki, Japan, 2Department of Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan |
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DWI and ADC values are widely used for tissue characterization. However, the relationship between the ADC values and the histological findings is still controversial. Weighted diffusion subtraction (WDS) was originally developed to eliminate T2 shine-through ambiguity in diffusion MRI evaluations. In this study, we applied WDS technique to diffusion weighted images of synovial sarcomas to evaluate the complex and heterogeneous tissue. Correspondence was found between WDS and histological findings on visual inspection. WDS seems to be a valuable visualization tool. |
| 1809 | Quantifying Reconstruction Uncertainty with Image Quality Transfer | |
1Computer Science, University College London, London, United Kingdom, 2Microsoft Research Cambridge, 3Institute of Neurology, University College London |
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Image quality transfer employs machine learning techniques to enhance quality of images by transferring information from rare high-quality datasets. Despite its successful applications in super-resolution and parameter map estimation of diffusion MR images, it still remains unclear how to assess the veracity of the predicted image in practice, especially in the presence of pathology or features not observed in the training data. Here we show that one can derive a measure of uncertainty from the IQT framework and demonstrate its values as a surrogate measure of reconstruction accuracy (e.g. root mean square error). |
| 1810 | Analyses of Diffusion kurtosis imaging for spleen with liver disease | |
1Tokyo Women's Medical University Yachiyo Medical Center, Yachiyo, Japan, 2The University of Tokyo Hospital, 3Tokyo women's Medical University Medical Center East |
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We evaluated the relationship between the mean kurtosis values (MK) and spleen size for the prediction of liver disease. As a result, there was no difference between the regular spleen and spleen with liver disease in the MK. Therefore, we consider that the splenic cell density and inner pressure remain unchanged even if patients have the enlarged spleen with liver diseases. |
| 1811 | Compact representation of the diffusion signal for multi-shell HARDI | |
1Centre for the Developing Brain, King's College London, London, United Kingdom, 2Division of Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom |
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With the advent of multi-shell acquisition, there is an increasing need for compact linear orthonormal representations of the DWI signal that extend over the radial as well as angular domain. In this work, we evaluate and compare 3 candidate basis function sets: spherical Bessel functions with and without reparametrization and the SHORE basis. Results show that the reparametrized Bessel functions and SHORE basis can faithfully represent the DWI signal with low numbers of parameters, and can be tuned to the properties of the signal independently of acquisition parameters. |
| 1812 | Characterizing diffusion weighted images using Clustering Analysis of Spherical Harmonics (CASH) | |
1Physics, University of Florida, Gainesville, FL, United States, 2Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States, 3Psychiatry, University of Florida, Gainesville, FL, United States, 4Biomedical Engineering, University of Florida, Gainesville, FL, United States, 5Clinical and Health Psychology, University of Florida, Gainesville, FL, United States, 6Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, United States |
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Diffusion weighted imaging has become an important tool for understanding how pathology affects brain structure. However, the standard method of diffusion tensor imaging (DTI) is inadequate in complex fiber regions. Other more complex diffusion models calculate the diffusion displacement probability function (DPF) 1, but current methods to extract the information from the DPF are limited. To this end, we introduce a data-driven method combining spherical harmonic representations of the DPF with the clustering analysis of spherical harmonic (CASH) coefficients, to provide an enhanced diffusion data characterization that includes information about the number of unique fiber orientations present in each voxel. |
| 1813 | Characterization of Spinal Cord DTI Metrics in Clinically Asymptomatic Pediatric Subjects with Incidental Congenital Lesions | |
1Radiology, Thomas Jefferson University, Philadelphia, PA, United States, 2Bioengineering, Temple University, Philadelphia, PA, United States, 3Radiology, Temple University, Philadelphia, PA, United States, 4Occupational Therapy, Thomas Jefferson University, Philadelphia, PA, United States |
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Synopsis: Hydromyelia and syringomyelia are essentially cystic abnormalities of the spinal cord (SC). The prevalence of these abnormalities in the clinically normal pediatric population is uncommon to rare. Out of 26 healthy typically developing (TD) pediatric subjects scanned in this study, 4 subjects had incidental findings of hydromyelia (n=3) and syringomyelia (n=1) lesions within the thoracic SC. These subjects were healthy and clinically normal. DTI parameters were calculated by using ROIs drawn on the whole cord along the entire SC. DTI parameters were significantly different in the cord above the subject with syringomyelia lesion compared to the TD subjects. However, no significant difference in DTI parameters was found in the cord above the subjects with hydromyelia lesions. This study demonstrates that DTI has the potential to be used as an imaging biomarker to evaluate the SC above and below the congenital lesions in asymptomatic subjects and one should use caution while including them into a normative data population. |
| 1814 | Can DTI Predict the MRI Level of Injury in Pediatric Spinal Cord Injury Subjects? | |
1Radiology, Thomas Jefferson University, Philadelphia, PA, United States, 2Biostatistics Consulting Cente, Temple University School of Medicine, Philadelphia, PA, United States, 3Radiology, Temple University, Philadelphia, PA, United States, 4Occupational Therapy, Thomas Jefferson University, Philadelphia, PA, United States, 5Bioengineering, Temple University, Philadelphia, PA, United States |
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The purpose of this study was to determine whether DTI parameters can be used to predict the level of injury as observed on conventional MRI data in pediatric spinal cord injury (SCI) subjects and to estimate the cut points for the DTI parameters which best discriminates the abnormal MRI from normal appearing MRI regions. Ten subjects with chronic SCI underwent repeat axial DTI scans based on inner field of view sequence. FA, MD, AD and RD were calculated by using ROIs drawn on the whole cord along the entire spinal cord for both scans. FA, MD, RD were significant predictors of the MRI level of injury. The cut points for FA, MD, AD and RD discriminated the abnormal MRI from normal appearing MRI regions in these subjects. DTI has the potential to serve as a surrogate for an abnormal MRI level corresponding to a region of SCI in instances where the MRI scans are unavailable, unreliable or there is an equivocal clinical exam. |
| Exhibition Hall | Tuesday 13:45 - 15:45 |
| 1815 | Towards interpretation of 3-tissue constrained spherical deconvolution results in pathology | |
1The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 2The Florey Department of Neuroscience, University of Melbourne, Melbourne, Australia |
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Multi-shell multi-tissue constrained spherical deconvolution (MSMT-CSD) and single-shell 3-tissue CSD (SS3T-CSD) resolve WM fibre orientation distributions and GM and CSF tissue compartments by deconvolving WM, GM and CSF response functions from the diffusion MRI data. We aim for more general interpretation of the “WM/GM/CSF” compartments obtained from 3-tissue CSD methods, specifically in the presence of pathology. We demonstrate their potential in this context and provide a simple framework that aids interpretation, with healthy tissues as a frame of reference. “CSF-like” partial volume is related to interstitial fluid, while “GM-like” partial volume may indicate gliosis, given an appropriate context. |
| 1816 | Evaluation of Motion-Compensated Spatially-Constrained IVIM (MC-SCIM) Model of Diffusion-weighted MRI for Assessment of Fibrosis in Crohn’s Disease using Surgical Histopathology Scores | |
1Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States, 2Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States, 3Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States |
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Distinguishing bowel regions with fibrosis and regions with active inflammation would be clinically useful in Crohn’s disease to determine best therapy. Commonly used ADC model of DW-MRI, which encapsulates multiple diffusion components into a single parameter, may not suffice to fully describe tissue microenvironments. IVIM model, which describes fast and slow diffusion components, is not commonly used in clinic because of challenges of reliably estimating its parameters due to noise and physiological motion. We recently introduced a motion-compensated spatially-constrained incoherent motion model (MC-SCIM) for reliable parameter estimation. Here we compared MC-SCIM parameters to scores of inflammation and fibrosis from histopathology. |
| 1817 | Potential value of turbo-spin echo diffusion-weighted imaging in nasopharynx: primary study for differential diagnosis between recurrent nasopharyngeal carcinoma and post-chemoradiation fibrosis | |
1Radiology, Guangdong General hospital, Guangzhou, People's Republic of China |
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In our study, we found significantly higher image quality, lesion conspicuity and less distortion of TSE-DWI based on Alsop method compared with SS-EPI according to image quality scores. Frustratingly, the SNR for TSE-DWI was lower than for SS-EPI and the result was consistent with other non EPI-DWI sequences in previous studies. Clinically, the low SNR of TSE-DWI remains a major concern. May be it is contributed to the long reception time and higher actual resolution of TSE images compared with SS-EPI and the more efficient k-space coverage of SS-EPI. The CNR of nasopharynx lesions on DW images was significantly better for TSE-DWI imaging than for SS-EPI imaging, which enables a better visual discrimination of nasopharynx lesions with TSE-DWI imaging. In conclusion, TSE-DWI with fewer artifacts and much higher resolutions, which was near impossible before, will make up for the slightly poorer SNR. The ADC values of the brainstem, which was less affected by the susceptibility artifacts and ghosts, showed no significant differences between the two DWI techniques. However, the ADC values of the lesions on TSE were significantly different than those on SS-EPI. This result is obtained coincide with the previous result.These differences may be primarily attributed to susceptibility artifacts and ghost that also resulted in inhomogeneous ADC maps because nasopharyngeal DWI is vulnerable to these artifacts. Therefore, the ADC measurements from TSE-DWI might be more accurate than those from SS-EPI. |
| 1818 | Intravoxel Incoherent Motion Diffusion-weighted MR Imaging of the Liver: Influence of Combined Respiratory-cardiac Triggering Method on Signal-to-noise Ratio and Repeatability of Quantitative Parameters | |
1Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China, 2Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 3Philips Healthcare |
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As extremely susceptible to various kinds of motions, diffusion-weighted magnetic resonance imaging always leads to insufficient image quality and poor reproducibility of quantitative measurements, especially for the liver. However, the use of combined respiratory-cardiac triggering, sychronizing data acquisitions with respiratory and cardiac cycles, could effective improve the signal-to-noise ratio and the repeatability of apparent diffusion coefficient and intravoxel incoherent motion parameters in the liver compared with respiratory triggering and free breathing without triggering method. |
| 1819 | High-Resolution Intravoxel Incoherent Motion (IVIM) with Generalized SLIce Dithered Enhanced Resolution Simultaneous MultiSlice (gSlider-SMS): Effect on CSF Partial Volume Contamination | |
1Department of Medical Imaging, University of Toronto, Toronto, ON, Canada, 2Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States |
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In this work, we introduce a high-resolution acquisition strategy for IVIM brain imaging using generalized Slider Simultaneous MultiSlice (gSlider-SMS) diffusion MRI. An SNR efficient multi b-value 10 simultaneous slice acquisition was used to obtain IVIM parameter maps with submillimeter isotropic resolution. Compared to a conventional acquisition (2 mm isotropic), high resolution IVIM provided improved delineation of the cortex and reduced partial volume contamination with CSF. Cortical perfusion measurements using the standard acquisition were falsely elevated by approximately 40% compared to gSlider-SMS IVIM. High resolution IVIM may provide more reliable perfusion information for evaluation of cortically based pathology. |
| 1820 | Diffusion weighted imaging of the cerebello-thalamic pathway after MR guided high intensity focused ultrasound (HIFU) thalamotomy | |
1Centro Integral de Neurociencias AC (CINAC), HM Puerta del Sur, Hospitales de Madrid, Móstoles, Spain, 2Centro Integral de Neurociencias AC (CINAC), HM Puerta del Sur, Hospitales de Madrid, Móstoles, 3CEU San Pablo University, Madrid, Spain |
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In here we aimed at characterizing the impact of the HIFU thalamotomy over the cerebello-thalamic pathway. We used probabilistic tractography to map the subject-specific anatomy of this pathway, we defined a set of regions along a group average pathway, and we extracted DTI based average values in these regions. We found local and distant alterations along the pathway 3-months post-treatment. These changes were strongly correlated with the clinical improvement of the patients. These findings serve to strengthen DWI, as a tool to aid in the targeting of HIFU in the treatment of essential tremor. |
| 1821 | Value of the Intravoxel Incoherent Motion MRI in Pretreatment Predicting and Monitoring the Early Response to Chemoradiotherapy in Esophageal Squamous Cell Carcinoma | |
1Hunan Cancer Hospital, Changsha, People's Republic of China, 2MR Research China, GE Healthcare, Beijing, People's Republic of China |
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Chemoradiotherapy (CRT) was considered to be a very effective treatment regimen for locally advanced or unresectable esophageal cancer (EC). Usually the therapy-induced early changes of tumor microenvironment were prior to morphological changes, which cannot be detected by traditional imaging techniques. This study used intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) to investigate the early response to CRT in esophageal squamous cell carcinoma (ESCC). It was found that the IVIM-DWI parameters (ADC and D) might be valuable in pretreatment predicting and monitoring the early treatment response to CRT in ESCC. |
| 1822 | Rectal Adenocarcinoma: Diagnostic Accuracy of Diffusion Kurtosis Imaging (DKI) and its Correlation with Prognostic Factors | |
1Radiology, Ruijin Hosptial, Jiaotong University, Shanghai, People's Republic of China, 2MR Collaboration NE Asia, Siemens Healthcare, Shanghai, People's Republic of China, 3APPL, Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, People's Republic of China |
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The high resolution MRI and conventional DWI suffers from unsatisfying accuracy in assessment of some prognostic factors of rectal adenocarcinoma. We employed DKI, a protocol mainly for evaluating the complexity of biologic tissues, to explore its diagnostic accuracy and correlation with prognostic factors. The kurtosis of DKI exhibited highest correlation with histologic grades especially the new grading criterion and higher potential in differentiation of high- and low grade tumors, and also in predicting nodal status, with higher specificity than or equivalent sensitivity to diffusivity and ADC. In conclusion, DKI could be a promising tool in predicting prognosis of rectal adenocarcinoma. |
| 1823 | A Comparison of Readout Segmented EPI and Interleaved EPI in High Resolution Diffusion Weighted Imaging | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, People's Republic of China, 2BIU Clinical Science MR, Philips Korea, Seoul, Korea, Republic of, 3Healthcare Department, Philips Research China, Shanghai, People's Republic of China, 4Vascular Imaging Laboratory, Department of Radiology, University of Washington, Seattle, WA, United States |
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Multi-shot interleaved EPI (iEPI) and readout segmented EPI (RS-EPI) are two alternative strategies for high resolution diffusion imaging. This study made a comparison of the two methods in different aspects. Our comparison showed that the iEPI had the advantage of largely reducing the geometric distortion. Both RS-EPI and iEPI could achieve high resolution diffusion tensor imaging. |
| 1824 | Evaluation of diffusion weighted imaging (DWI), kurtosis imaging (DKI) and q-space imaging (QSI) for profiling whole human breast tumour tissue microstructure | |
1Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, United Kingdom, 2Breast Unit, Aberdeen Royal Infirmary, Aberdeen, United Kingdom, 3School of Medicine, University of Aberdeen, Aberdeen, United Kingdom, 4Pathology Department, Aberdeen Royal Infirmary, Aberdeen, United Kingdom, 5MRI Unit, The Francis Crick Institute, London, United Kingdom |
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We investigated a clinically viable QSI protocol in whole breast tumours excised from patients on a clinical scanner within a clinically feasible time frame. QSI has been largely limited to the preclinical setting, requiring strong gradients and a long acquisition time. We compared QSI against conventional DWI and DKI and found that diffusion indices across these techniques were consistent. Previous studies have shown that QSI provides a comprehensive characterisation of tissue microstructure, particularly in the presence of restricted diffusion. These results provide pivotal foundation for the clinical translation of QSI in breast cancer diagnosis and prognosis. |
| 1825 | Effect of hyperglycemia on deep nucleus microstructure and iron deposition in people with type 2 diabetes: a DKI and SWI study | |
1Department of Radiology,First Affiliated Hospital of Dalian Medical University, Dalian 116011, People's Republic of China, 2GE healthcare China, Beijing |
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In this paper,the experimental group and the control group were respectively used as the people with type 2 diabetes and the health people ,the effect of high blood glucose on the microstructure and iron deposition in patients with type 2 diabetes mellitus was studied used DKI and SWI study,and it is concluded that the high blood glucose level may have certain damage to the microstructure of the deep core.Furthermore,iron deposition may exacerbate the damage of microstructure.In conclusion,DKI and SWI study can evaluate secondary brain microstructure changes from hyperglycemia in T2DM patients. |
| 1826 | Optimal strategy for measuring intraventricular temperature using second-order motion compensation DWI | |
1Department of Radiology, Tokai university hospital, Isehara, Japan, 2Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan, 3Radiology, Tokai University School of Medicine, Isehara, Japan, 4Healthcare department, Philips Electronics Japan, LTD, Japan |
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A method for monitoring the intraventricular cerebrospinal fluid (CSF) temperature calculated from the DWI is affected by the CSF pulsation. Moreover, DWI should be obtained by optimal b value according to the diffusion coefficient of the measuring tissues. We investigated the second-order motion compensation DWI (2nd-MC DWI) to the determination of the intraventricular temperature to improve that accuracy with optimal b value. In the case of using the optimal b value based on the literature (ie., approximately 400 s/mm2), the intraventricular temperature can be more accurately estimated with 2nd-MC DWI than conventional |
| 1827 | Estimation of a novel set of intra and extracellular diffusivity parameters from modern DW-MRI | |
1Computer Science, Centro de Investigacion en Matematicas, Guanajuato, Mexico, 2Computer Science Department, University of Verona, Italy, 3University Hospital Center (CHUV) and University of Lausanne (UNIL), Switzerland, 4Signal Processing Lab (LTS5), École Polytechnique Fédérale de Lausanne, Switzerland |
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We present a novel framework to estimate on in-vivo data a) independent intra and extracellular axial-diffusivities, b) extracellular radial-diffusivity, c) non-parametric bundle dispersion, d) axonal diameter indexes, and e) intracellular volume fractions. Our methodology does not fix a priori the value of any of these parameters or uses tortuosity models on the extracellular radial diffusivity. The proposal is an extension of the ED^3 method, which provided the best solution on the signal prediction on the White Matter Modelling Challenge 2015. We perform a comprehensive set of synthetic experiments under realistic conditions to validate the capabilities of the proposal. |
| 1828 | Prediction of Radiotherapy Response in Nasopharyngeal Carcinoma Patients Using Diffusion-Kurtosis Imaging | |
1Department of Radiology, Hainan General Hospital, Haikou, People's Republic of China, 2Department of Radiology, Hainan General Hospital, People's Republic of China, 3Department of Radiology, Hainan General Hospital, Haikou, China, People's Republic of China, 4department of Radiology, Hainan General Hospital, People's Republic of China, 5MR scientific marketing NE Asia, Siemens Healthcare |
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The first row: A 62-year-old man with NPC who was a nonresponder. The lesions located at the left nasopharyngeal wall and cavum. Manual draw an ROI within the boundaries of the NPC on Kmean map. The tumor’s maximum diameter was 3.5 before radiotherapy. Residual tumor was detected after radiotherapy. Mean Dmean and Kmean values were 1.48 10-3 mm2/s and 0.72 before treatment. The second row: A 63–year-old man with NPC who was a responder. The lesion affect the bilateral mucous membrane of the nasopharynx. The tumor’s maximum diameter was 3.09 before radiotherapy. No residual tumor was detected after radiotherapy. Mean Dmean and Kmean values were 1.22 10-3 mm2/s and 0.83 before treatment. NRG: non response group RG: reponse group |
| 1829 | Effect of gadolinium contrast agent on IVIM derived parameters of abdominal organs | |
1Radiology, Changhai Hospital of Shanghai, Shanghai, People's Republic of China, 2MR Collaboration NE Asia, Siemens Healthcare, Shanghai, People's Republic of China |
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This study investigated potential effects of gadolinium contrast agent on the IVIM derived parameters such as Dfast (blood microcirculation), Dslow (pure extravascular water diffusion), f (perfusion fraction) and the commonly used DWI-derived ADC of abdominal organs. The result shows that gadolinium administration does not make statistically significant differences in Dslow, Dfast, f or ADC of the liver, spleen, or pancreas. In the kidney, however, ADC values are significantly lower with post-contrast than pre-contrast. |
| 1830 | Imaging energy landscapes | |
1Department of Biomedical Engineering, Linköping University, Linköping, Sweden, 2Department of Physics, Bogazici University, Istanbul, Turkey, 3Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States |
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We discuss the usage of a recently-proposed diffusion-sensitising gradient waveform for the purpose of imaging the potential energy landscape in which water molecules diffuse. The energy landscape encodes information about bulk heterogeneities of the medium as well as effects such as adsorption at the boundaries. |
| 1831 | IVIM-derived parameters in evaluating the pathological features and hypoxia of nasopharyngeal carcinoma xenografts | |
1Radiology, Fujian Medical University Cancer Hospital, Fuzhou, People's Republic of China, 2Radiation Oncology, Fujian Medical University Cancer Hospital, Fuzhou, People's Republic of China, 3Philips Healthcare, Shanghai, People's Republic of China |
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Intravoxel incoherent motion diffusion weighted imaging was conducted on different radio-sensitive human NPC xenografts (CNE-1 and CNE-2) in order to investigate its application value in assessing the pathological features and tumor’s hypoxia of xenografts. CNE-2 xenografts of higher radio-sensitivity behaved greater changes on IVIM-parameters than CNE-1 xenografts of lower radio-sensitivity after fractional radiations. D and f values correlated significantly with the pathological features and tumor’s hypoxia of xenografts. Thus, IVIM-parameters is potentially valuable in evaluating the effect of radiotherapy in NPC. |
| 1832 | High-resolution diffusion imaging of post-mortem monkey brain: comparison of 3D Spin Echo and 3D segmented EPI sequence at 11.7T | |
1Center of NeuroImaging Research - 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, 3AP-HP, Hôpital de la Pitié-Salpêtrière, Department of Neurosurgery, Paris, France, 4AP-HP, Hôpital de la Pitié-Salpêtrière, Department of Neurology, Paris, France |
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Diffusion-weighted spin echo (SE) acquisition is the golden-standard of diffusion imaging, yet it is limited by a very long acquisition time. This work present the optimization of a 3D segmented Echo Planar Imaging (EPI) sequence with the goal of reducing acquisition time and be able to perform tractography and to promote further analysis such as microstructure or histology correlation. |
| 1833 | Comparaison of in vivo and ex vivo high resolution imaging of the mouse brain at 11.7T | |
1Center of NeuroImaging Research - 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, 3Behavior, Emotion and Basal Ganglia (BEBG), Brain and Spine Institute, Paris, France |
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This study compares high resolution in vivo and ex vivo diffusion imaging of mouse brain at 11.7T. The study shows that even with the advancement in image sequences and equipment, ex vivo imaging remains superior to in vivo imaging in terms of resolution with clear delineation of brain structures. However, fractional anisotropy values obtained from ex vivo imaging may not be a true representation of the in vivo condition. Nonetheless, the resolution obtained from in vivo imaging should allow for longitudinal studies. |
| 1834 | Comparison of MUSSELS vs MUSE for Multi-Shot Diffusion Imaging | |
1Department of Radiology, University of Iowa, Iowa City, IA, United States, 2Department of Electrical and Computer Engineering, University of Iowa, Iowa City, IA, United States, 3GE Healthcare |
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Multi-shot diffusion weighted (MS-DW) imaging can offer reduced echo-time (TE) and improved SNR to enable high spatial resolution applications. However, the reconstruction of the high resolution diffusion weighted images (DWI) from the multiple shots is challenging because of the presence of motion-induced phase variations between shots. Recently, two methods were proposed to reconstruct the phase-compensated DWIs. In this work, we compare the performance of the methods, MUSE and MUSSELS, to reconstruct the DWIs from a MS-DW acquisition. |
| 1835 | Fiber connection density differences detected in patients with sickle cell disease | |
1Radiology, Children's hospital Los Angeles, Los Angeles, CA, United States, 2Radiology, Children's hospital, Los Angeles, CA, United States, 3Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, 4Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States, 5Sherbrooke Connectivity Imaging Lab (SCIL), Computer Science Department, University of Sherbrooke, Sherbrooke, QC J1K 0A5, Canada, 6Hematology, Children's hospital, Los Angeles, CA, United States, 7Cardiology, Children's hospital, Los Angeles, CA, United States |
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Sickle cell disease (SCD) is a chronic disorder characterize by progressive cerebrovascular damage. We hypothesized that subtle cerebral injury might be visible with diffusion imaging data in these patients. Tractography based on the fiber orientation distribution function (ODF) was applied in order to investigate the character and severity of white matter injury in patients with SCD. We found both decreased and increased fiber density in patients, compared to control subjects that co-localized with silent cerebral infarctions. These data suggest progressive white matter injury and compensatory mechanisms in SCD patients. |
| 1836 | Diffusion weighted imaging in thyroid nodule: comparison of readout-segmented EPI and single-shot EPI Techniques | |
1Radiology, Changhai Hospital of Shanghai, Shanghai, People's Republic of China, 2Application development, Siemens Shenzhen Magnetic Resonace Ltd, Shenzhen, People's Republic of China |
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Diffusion weighted imaging showed the potential to evaluate thyroid disease. This study aimed to evaluate whether readout-segmented EPI (RS-EPI) can provide better image quality in imaging thyroid gland in comparison with single-shot EPI (SS-EPI), and to compare ADC values, acquired from RS-EPI with those of SS-EPI. Sixteen patients were examined using both techniques. There were significant differences in susceptibility, motion artifacts, except for detectability of thyroid nodules and ADC measurements between RS-EPI and SS-EPI. The present study found that the RS-EPI technique provides significant image quality improvement compared with SS-EPI in imaging thyroid gland at 3 Tesla. |
| 1837 | Towards a practical protocol for accurate and reliable MR-derived diffusion changes of the optic nerve in optic neuritis | |
1Diagnostic Radiology, Singapore General Hospital, Singapore, Singapore |
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Optic neuritis is a demyelinating inflammation of the optic nerve that often occurs in association with multiple sclerosis and neuromyelitis optica. Magnetic resonance imaging (MRI), especially diffusion-tensor imaging (DTI) is highly sensitive for inflammatory changes in the optic nerves. We propose a DTI protocol which balances susceptibility artefacts, scan time, and resolution for better image quality and clinical practicality. It allows a 1 mm in-plane resolution in order to avoid partial volume averaging with cerebrospinal fluid (CSF) surrounding the optic nerve in examining fractional anisotropy (FA) values and apparent diffusion coefficient (ADC) for severity of optic neuritis. |
| 1838 | Joint estimation of free water and perfusion fraction in human brain | |
1Department of Medical Radiation Physics, Lund University, Lund, Sweden, 2Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States, 3Department of Radiology (Adjunct), Johns Hopkins School of Medicine, Baltimore, MD, United States |
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The perfusion of blood affects the estimation of diffusivities, especially fast components such as free water. Here, we acquired human data to demonstrate the applicability of a three-compartment model for the joint estimation of tissue diffusivities, free water, and the perfusion fraction. We evaluated the feasibility of the model by comparing a multiple b-value approach with a shorter, clinically feasible approach. The conclusion is that the two-compartment free-water estimation is affected by both water and blood. The three-compartment model disentangles these effects, useful in distinguishing between changes originating from capillary blood from those originating from the extracellular space. |
| 1839 | Fractional motion related diffusion MRI in the detection of acute ischemic stroke | |
1MR Research China, GE Healthcare, Beijing, People's Republic of China, 2Center for MR Research, Peking University, Beijing, People's Republic of China, 3Department of Radiology, Beijing Tiantan Hospital, Beijing, People's Republic of China |
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The use of FM model has been demonstrated in distinguishing low- and high-grade pediatric brain tumors. However, its feasibility in detecting acute stroke has not yet been investigated. In this work, FM model was applied in patients with acute ischemic stroke and compared with traditional ADC to investigate its clinical potential. |
| 1840 | Model-Based Joint Reconstruction for Multi b-Value Diffusion-Weighted Imaging | |
1School of Biomedical Engineering, Guangdong Provincial Key Laborary of Medical Image Processing, Southern Medical University, Guangzhou, People's Republic of China, 2Philips Healthcare (Suzhou), Suzhou, People's Republic of China, 3Philips Healthcare, Guangzhou, People's Republic of China, 4Department of Biomedical Engineering, Zhejiang University, Hangzhou, People's Republic of China, 5laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, People's Republic of China, 6Department of Electrical and Electronic Engineering,The University of Hong Kong, Hong Kong SAR, People's Republic of China, 7Neusoft Medical System, Shanghai, People's Republic of China |
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In current multi b-value DWI, each b-value image is usually reconstructed independently by using parallel MRI techniques. In this work, we propose a model-based joint reconstruction method for the reconstruction of under-sampled multi b-value DWI data. The proposed method can directly estimate quantitative parameters form k-space data, and exploit inter-image constraint to improve the quality of reconstructed image. |
| 1841 | High Resolution Cardiac DTI - Fiber Tractography Statistics of the ex Vivo pig Heart | |
1Comprehensive Heart Failure Center, University Hospital Wuerzburg, Wuerzburg, Germany, 2Department of Diagnostic and Interventional Radiology, University Hospital of Wuerzburg, Wuerzburg, Germany, 3Department Tissue Engineering and Regenerative Medicine, University Hospital Wuerzburg, Wuerzburg, Germany, 4Translational Center Wuerzburg 'Regenerative therapies', Wuerzburg branch of the Fraunhofer IGB, Wuerzburg, Germany |
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A whole heart, high resolution diffusion tensor data set with 1.3 mm isotropic voxels was acquired in 15 ex vivo pig hearts using a Stejskal-Tanner sequence at 3T. ADC, FA and HA values were calculated and analyzed for the whole heart. Purpose was to create a reliable statistical reference of diffusion parameters. Sharp modes for median and interquartile range of the ADC and median and mean values of the helix angle indicate similar distributions of those values for the individual hearts. This provides a statistically compelling reference for future cardiac DTI pig studies in vivo and at higher field strengths. |
| 1842 | In Vivo 3D Single-Shot Echo-Planar DWI at 7T for Mapping Tissue Microstructure using Mean Apparent Propagator (MAP) MRI | |
1Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, Bethesda, MD, United States, 2Radiology and Radiological Sciences, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 3Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States, 4Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States |
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A number of advanced diffusion models have demonstrated great promise for mapping tissue microstructure in ex vivo studies with high resolution and fidelity using a wide range of diffusion weightings, but the increased acquisition time (days) is not feasible in vivo. In this study we have addressed some basic DWI acquisition pitfalls by using 3D single-shot EPI on a high-field (7 Tesla) pre-clinical MRI system, and adapted one of the most promising diffusion modeling techniques, mean apparent propagator (MAP) MRI in vivo to derive information about rat brain microstructure within a reasonable time frame. |
| 1843 | Intravoxel Incoherent Motion (IVIM) in Evaluation of Orbital Masses | |
1Department of Radiology, Renmin Hospital of Wuhan University, Wuhan, People's Republic of China, 2GE Healthcare China, Shanghai, People's Republic of China |
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Diffusion-weighted imaging (DWI) has been proven that malignant orbital masses demonstrate significantly and visually appreciable lower apparent diffusion coefficient (ADC) than benign orbital masses[1-2]. Nevertheless, ADC cannot separate the pure molecular diffusion from the motion of water molecules in the capillary network; thus, perfusion contamination would increase the ADC value. According to the IVIM DWI model[3], both microscopic perfusion and diffusivity can be separated using a biexponential decay function, providing additional parameters for tissue characterization. From the result we can see that it is feasible that quantitative parameters of orbital masses can be derived from IVIM DWI. |
| 1844 | Harmonization for DTI measurements mapping across sites in multi-center MRI study | |
1Department of Biomedical Engineering, the Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Xi'an Jiaotong University, Xi'an, People's Republic of China, 2Xidian University, Xidian University, People's Republic of China, 3Center for Language and Brain, Shenzhen Institute of Neuroscience, Shenzhen University, shenzhen, People's Republic of China, 4Department of Radiology, the First Affiliated Hospital, Xi’an Jiaotong University, xi'an, People's Republic of China, 5Department of Radiology, the First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, People's Republic of China, 6MR Research China, GE Healthcare, Beijing, People's Republic of China, 7Department of Radiology, Xijing Hospital, Fourth Military Medical University, Xi'an, People's Republic of China, 8Department of Radiology, Xijing Hospital, Fourth Military Medical University, xi'an, People's Republic of China, 9Department of Diagnostic Radiology, Xi’an Children Hospital, Xi'an, People's Republic of China, 10Department of Radiology, Xi’an Gao Xin Hospital, Xi'an, People's Republic of China, 11Department of MRI Diagnosis, Shannxi Provincial People’s Hospital, Xi'an, People's Republic of China |
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Despite the fact that multi-site diffusion imaging studies are increasingly used to study brain disorders, but it is noteworthy that there are large differences among diffusion measurements from different sites. The current study aimed to confirm the variability and to harmonize data across sites. Our results indicated that not only DTI metrics in human brain within inter-site but also within inter-site changed obviously. Furthermore, a brain voxel-based model was developed to harmonize the DTI metrics and to reduce the deviation compared with reference site data and thus improve the reliability of group analysis in multi-center study. |
| 1845 | Benefits of flow, eddy current and concomitant field compensation in diffusion weighted MRI | |
1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany, 2Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, United Kingdom, 3Institute of Radiology, University Hospital Erlangen |
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Diffusion-weighted MRI suffers from artifacts due to flow, concomitant fields and eddy currents. Different combinations of compensation for these effects were examined in phantom measurements as well as in vivo in the brain and in the prostate. The signal variations in the phantom measurements indicate that it could be advantageous to simultaneously compensate of all three effects over only flow and concomitant field compensation. This could not be seen in the in vivo results, where flow and concomitant field compensation proved to be as good as the full compensation. |
| 1846 | Diffusion Diffraction Inside Out | |
1Dpt of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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Diffusion diffraction, a famous result on NMR in porous media founds little application to in-vivo MRI. Beyond the high technical requirements, the reason can be seen in the principal limitations of this technique. It probes the shape of identical closed pores, which are not typical in-vivo. In this work, we generalize diffusion diffraction for an infinite connected compartment outside impermeable inclusions such as space external to biological cells with low membrane permeability. The signal at high diffusion weighting is expressed in terms of the inclusions' correlation function. The developed theory is supported by experiments in aqueous suspension of polystyrene microbeads. |
| 1847 | Investigation of Diffusion Tensor Indices by ROI analysis and TBSS of Patients with Depressive Symptoms in the Elderly with Dementia | |
1Department of Radiology, Taichung Veterans General Hospital, Taichung, Taiwan, Taichung, Taiwan, 2Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, Taichung, Taiwan, 3Department of Biomedical Engineering, HungKuang University, Taichung, Taiwan, Taichung, Taiwan, 4College of Medicine, China Medical University, Taichung, Taiwan, Taichung, Taiwan |
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The differences of indices in diffusion tensor images (DTI) of patients with dementia are well-discussed in recent years. However, the comorbidity of dementia and depression was observed. In this study, we focused on the white matter changes associated with depressive symptoms in dementia and the relationship between DTI indices and cognitive functions in depressed and non-depressed patients. By an ROI-based analysis of the indices and TBSS analysis in DTI, we investigated the differences between patients of dementia with depression and without depression. Furthermore, we correlate the differences with the score of some clinical cognitive test to figure out the subtle differences. |
| 1848 | Myocardium Tissue DTI with Stimulated Echo at Large Susceptibility Induced B0 gradients: Examination of the Shimming Strategies Efficiency and Errors. | |
1Comprehensive Heart Failure Center, University Hospital Wuerzburg, Wuerzburg, Germany |
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In this paper, we investigated experimentally and statistically the effect of distortions of myocardium DTI with STEAM-EPI due to susceptibility induced gradients varied in a range of factor 10 to 20 to the reference. The special focus was given to examining the effect of prolonged EPI-readout, B0-shimming effect and motion-induced shimming errors relevant for high-resolution DTI in-vivo. Fresh ex-vivo pig hearts were used for DTI measurements with an in-house developed STEAM-EPI sequence. The distribution of diffusion directions components was found well preserved for prolonged readout even at high internal gradient. |
| 1849 | Validating Particle Dynamics in Monte Carlo Diffusion Simulation using the Finite Element Method | |
1Computer Science, Centro de Investigacion en Matematicas, Guanajuato, Mexico, 2Department of Computer Science and Centre for Medical Image Computing, University College London, London, United Kingdom |
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Monte-Carlo Diffusion Simulation (MCDS) is commonly used to develop and validate analytical models for quantifying tissue microstructure using diffusion MRI. However, the validation of the tools implementing MCDS has been limited, especially for complex domains, such as the extra-cellular space of brain tissue. To address this challenge, we propose a novel framework using the Finite Element Method (FEM), an established method for solving the diffusion equation with complex domains, to provide the ground-truth to assess MCDS. We demonstrate the framework by assessing how the accuracy of MCDS is influenced by the number of particles and the number of diffusion steps. |
| 1850 | Distortion free whole-body diffusion weighted imaging using a self-adaptive post deformation algorithm | |
1GE HealthCare, MR Research China, Beijing, People's Republic of China, 2Department of Radiology, Peking Union Medical College Hospital, People's Republic of China |
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Conventional Whole-Body DWI that consists of several sequential stations often troubled geometric distortions and signal drops in areas with strong susceptibility, such as the neck and lumbar vertebra. The aim of this study was to propose a new WBDWI protocol and post process deformation algorithm to get distortion free whole body images. Consistently good results were received and in helps to diagnose several cases of tumors that were previously unclear to the volunteers and patients. |
| 1851 | A longitudinal follow-up study of levator ani muscle injury during vaginal delivery using diffusion tensor imaging | |
1Tianjin First Center Hospital, tianjin, People's Republic of China, 2Philips Healthcare, Beijing, China, beijing, People's Republic of China |
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Levator ani muscle (LAM) injury has been known to be highly associated with vaginal delivery, the natural recovery course of injured LAM is unclear recurrently. Diffusion tensor imaging (DTI) with fiber tracking is a useful noninvasive MRI technique, which can be used to assess pelvic floor muscles injury and recovery quantitatively, and the fiber tract can display the direction and thickness of LAM fibers. In this study, we tried to apply DTI imaging to explore the natural recovery course of LAM injury during vaginal delivery. And the results showed that the injured LAM during vaginal delivery has some degree of repair as time goes on. |
| 1852 | Shortening acquisition time and increasing resolution to (1 mm)³ isotropic in 7T diffusion MRI (dMRI) still allows resolving fiber orientations and fiber crossings: a step towards clinical applications? | |
1Biometry and Medical Informatics, University of Magdeburg, Magdeburg, Germany, 2Siemens Healthcare GmbH, Erlangen, Germany, 3Neurosurgery, University of Magdeburg, Magdeburg, Germany, 4Leibniz Institute for Neurobiology, Magdeburg, Germany, 5Neurology, University of Magdeburg, Magdeburg, Germany |
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Prior results in single-shot diffusion weighted EPI indicated that voxel sizes below (1.4mm)3 prohibit reliable resolution of fiber orientations and fiber crossings. Here we compare zoomed single-shot EPI with (1mm)³ isotropic resolution with readout-segmented EPI with (1.4mm)³ and (1.0mm)³ isotropic at ultra-high field strength of 7 Tesla. In all cases, fiber density orientation maps could be determined reliably thus enabling a resolution of main fiber directions and crossings even at (1mm)³ resolution. |
| 1853 | Applied Research of Diffusion Tensor Imaging in traumatic tibial nerve injury | |
1Radiology Department of the 251 st Hospital of PLA, Zhangjiakou, People's Republic of China, 2HeBei North University, Zhangjiakou, People's Republic of China, 3GE Healthcare, MR Research China, BeiJing, People's Republic of China |
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DTI plays an important role in detecting nerve injury. It offers a great opportunity for imaging the tibial nerve injury follow trauma.In this work, we demonstrated DTI combined with DTT can clearly review the morphological transformation of Nerve fiber after tibial nerve injured; quantitatively analyze the damage degree,which can provide detailed information for clinical treatment. |
| 1854 | Scan time reduction in DWI of the pancreas using simultaneous multislice technique with different acceleration factors: how fast can we go? | |
1Department of of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen, Germany, 2Section on Experimental Radiology, Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen, Germany, 3Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany |
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We investigated the feasibility of simultaneous multislice-accelerated diffusion-weighted imaging of the pancreas using an acceleration factor of 2 and 3 (sms2/sms3-DWI) and its influence on image quality, acquisition time and apparent diffusion coefficients in comparison to conventional sequences (c-DWI) in ten healthy volunteers and 20 patients at 1.5 T. Images recorded with sms2-DWI offered high quality with a scan time reduction to one third; sms3-DWI showed significantly poorer overall image quality. In conclusion, sms2-DWI is feasible in clinical routine providing high image quality and a substantial reduction of acquisition time, whereas the use of higher acceleration factors is currently not recommended. |
| 1855 | Robustness of kurtosis acquisition via simultaneous multi-slice EPI: a test-retest in children | |
1Medical Physics department, Bambino Gesù children's hospital, Rome, Italy, 2Imaging Department, Bambino Gesù children's hospital, Rome, Italy, 3Medical Physics department, Bambino Gesù children's hospital, ROME, Italy |
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Diffusion kurtosis imaging is an emerging technique based on non-gaussian diffusion of water in biologic systems and provides complementary information to the traditional diffusion. Although the method is very promising in identifying new biomarkers, it suffers from long time acquisition, which is very challenging in . However, a recent technique, named simultaneous multi-slice (SMS) acquisition, allows multiple slices acquisition thus drastically reducing the acquisition time. The purpose of this work is then to study the robustness of diffusion kurtosis in children when acquired via sms method. |
| 1856 | Mental training effects on adolescent brain networks | |
1Radiology & Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Psychiatry, University of California, San Francisco, San Francisco, CA, United States, 3Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden, 4Clinical Sciences, Umeå Universitet, Umeå, Sweden, 5Psychology and Neurosciences Program, Stanford University, Stanford, CA, United States, 6PGSP-Stanford PsyD Consortium |
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In this study we used diffusion MRI network analyses to examine the effects of a 12-week training of attention and emotion regulation. Our preliminary results in 24 healthy adolescents demonstrate an improvement of executive attention and an increase of the node strength of the left anterior cingulate cortex. |
| 1857 | Analytical Solutions of Bloch NMR Flow Equations: Emerging and Future Diffusion Magnetic Resonance Imaging | |
1Physics, Federal University of Technology, Minna, Nigeria, Minna, Niger State, Nigeria |
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Diffusion imaging has proved to be very important in clinical diagnosis and its exclusive application to numerous medical problems is currently plagued with some limitations which is most pronounced in heterogeneous voxels. In order to address this problem, we have presented an analytical method with which diffusion MR signals can be evaluated from point to point within a voxel of interest. The proposed method is shown to be useful in brain tumor diagnosis and general computational tissue imaging. The interesting part of this method is that only few data are required for image reconstruction. |
| 1858 | Diffusion Tensor Imaging of human muscle at ultra-high-field (7T) MR. | |
1Department of Biomedical Imaging and Image-guided Therapy- MR Centre of Excellence, Medical University of Vienna, Vienna, Austria, 2Orthopedic Department, Evangelisches Krankenhaus Wien, Vienna, Austria, 3Siemens Healthcare GmbH, Erlangen, Germany |
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Ultra-high-field (7T) imaging already demonstrated to provide more robust DTI measurements in comparison to 1.5 and 3T in the brain but, to the best of our knowledge, it was not applied for DTI measurements on human muscles. Our results showed higher SNR as well as an overall improvement in DTI metrics for the entire calf muscle at 7T than at 3T. Single muscle analyses (gastrocnemii, tibialis anterior) demonstrated more heterogeneous results. Future studies including a larger population and considering technical challenges (e.g.,RF inhomogeneity, gradient performance) are necessary to assess if 7T may provide higher benefits in specific muscles. |
| 1859 | Effect of Velocity-compensated Diffusion Preparation for Spinal Cord Diffusion Imaging | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, People's Republic of China, 2Vascular Imaging Laboratory, Department of Radiology, University of Washington, Seattle, WA, United States |
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The spinal cord and surrounding cerebrospinal fluid undergo significant cardiac pulsations, which can influence the microscopic motion-sensitive diffusion preparation and cause signal void in the diffusion images. In this work, velocity-compensated diffusion-encoding gradient waveform was implemented in spinal cord diffusion imaging and the images are compared with traditional monopolar preparation and cardiac gating approaches. Results show that with velocity-compensated diffusion preparation, the spinal cord diffusion imaging shows fewer signal voids compared to the traditional monopolar diffusion preparation. Using velocity-compensated diffusion preparation without cardiac triggering can provide a new approach for spinal cord diffusion imaging. |
| 1860 | The diffusion kurtosis imaging findings of preoperative glioma-related epilepsy | |
1The First Affiliated Hospital of Zhengzhou University, Zheng Zhou, People's Republic of China, 2The First Affiliated Hospital of Zhengzhou University, 3MR Scientific Marketing Specialist, Siemens Healthcare Ltd.,Shanghai,201318, China |
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MK not only reflects the microstructure of the glioma， but also may reflect neurotransmitter metabolism microenvironment. |
| 1861 | Diffusion Entropy of Fractional Anisotropy Values in White Matter in Mild Traumatic Brain Injury | |
1Pediatrics, University of British Columbia, Vancouver, BC, Canada, 2University of British Columbia, Vancouver, BC, Canada, 3Radiology, University of British Columbia, Vancouver, BC, Canada, 4Division of Sports Medicine, University of British Columbia, Vancouver, BC, Canada |
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A paper in Radiology by Delic et al. in 2016 looked at the Shannon entropy of fractional anisotropy values in white matter in the brains of people with mTBI and controls, and found significant differences between the two. We attempted to replicate their findings with retrospective mTBI data of our own. We did not find any significant differences with controls, and ice hockey athletes concussed after two weeks. We also did not find any changes in concussed athletes comparing data before injury with data after 3 days, 2 weeks, and 2 months. |
| 1862 | Exploring Cortical Fiber Crossings in Mice using Diffusional Kurtosis Imaging | |
1Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, United States, 2Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, United States, 3Department of Neurology, Medical University of South Carolina, Charleston, SC, United States, 4Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States |
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The ability of diffusional kurtosis imaging (DKI) to detect multiple intravoxel fiber directions in vivo is demonstrated for mouse cortex, with two or more directions being detected in the majority of voxels. The distribution of angular differences between the different fiber directions for individual voxels peaked at near 90o, suggestive of a grid-like pattern of neurites. Our findings support the feasibility of DKI-based tractography in mouse cortex. |
| 1863 | A Study on Total-Variation Regularization for Model-Based Reconstruction in DTI | |
1Dept. of Electrical and Computer Engineering, University of Utah, SALT LAKE CITY, UT, United States, 2Department of Biomedical Engineering, University of Utah, SALT LAKE CITY, UT, United States, 3Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Shenzhen, People's Republic of China, 4Department of Radiology and Imaging Sciences, University of Utah, SALT LAKE CITY, UT, United States, 5Department of Biomedical Engineering, The State University of New York (SUNY) at Buffalo, NY, United States |
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In this work, we study total-variation (TV) regularization for model-based reconstruction from undersampled DTI data. Various TV regularization methods are examined. Using ex-vivo brain DTI data, we show that imposing TV constraints on DWI provide more reliable quantitative estimates of diffusion than those imposing TV constraints directly on the tensor. A gradient descent algorithm with line backtracking is used for better convergence to optimal solution. For highly undersampled data of 12 diffusion encoding directions and a reduction factor of R=4, we show that good estimates of primary eigen-vector, fractional anisotropy, and mean diffusivity can still be obtained using TV-based regularization. |
| 1864 | Repeatability of apparent diffusion coefficient and intravoxel incoherent motion parameters at 3.0 Tesla in orbital masses. | |
1Radiology, Fondation Ophtalmologique Adolphe de Rothschild, Paris, France, 2Radiology, Hôpital Européen Georges Pompidou, Paris, France |
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- IVIM technique is feasible in the orbit with a good to acceptable repeatability of ADC and D. (coefficient of variation range 12%-25%) - Interobserver repeatability agreement is excellent for all the IVIM parameters in the orbit. (intraclass correlation coefficient range 90-95%) - The use of PF or D* as biomarkers should be cautious because of high test-retest and interobserver variabilities. |
| 1865 | Functional Assessment of Lumbar Nerve Roots Using Direct Coronal Single-Shot Turbo Spin-Echo Diffusion Tensor Imaging - Application to Patients with Bilateral Spinal Canal Stenosis Showing Unilateral Neurological Symptom - | |
1Radiology, Eastern Chiba Medical Center, Chiba, Japan, 2Philips Electronics Japan, Tokyo, Japan, 3Orthopaedic Surgery, Eastern Chiba Medical Center, Chiba, Japan, 4Kanazawa University, Ishikawa, Japan |
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Clinically, there are some patients with spinal canal stenosis who have unilateral neurological symptom despite the existence of bilateral nerve compression on the conventional MRI images. The purpose of this study was to investigate the availability of TSE-DTI for patients with bilateral spinal canal stenosis who have unilateral neurological symptom. At the level responsible for symptom, the average FA values of symptomatic side were significantly lower than those of asymptomatic side. FA values of TSE-DTI might be helpful in identification of responsible lumbar nerves roots for patients with bilateral spinal canal stenosis who have unilateral neurological symptom. |
| 1866 | Investigation of Diffusion Tensor Indices by TBSS analysis and of Patients with symptoms of neuropsychiatric systemic lupus erythematosus | |
1Department of Radiology, Taichung Veterans General Hospital, Taichung city, Taiwan |
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In this project, we attempted to study the NPSLE subjects without abnormal lesion in conventional MR imaging in order to investigate the effective imaging biomarkers in early detection of neurological degeneration. Brain diffusion-tensor imaging with TBSS analysis was performed for studying the micro-structural alternations in NPSLE patients. The preliminary results illustrated statistically significant differences of FA and MD in some important nerve tracts between NPSLE patients and normal volunteers. There also existed a significant difference between NPSLE patients with and without depression. |
| 1867 | Age Related Diffusion and Tractography Changes in Typically Developing Pediatric Cervical and Thoracic Spinal Cord | |
1Temple University, Philadelphia, PA, United States, 2Drexel University, Philadelphia, PA, United States, 3Radiology, Thomas Jefferson Hospital University, Philadelphia, PA, United States, 4Occupational Therapy, Thomas Jefferson Hospital University, Philadelphia, PA, United States, 5Radiology, Temple University, Philadelphia, PA, United States |
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This study investigates age related changes in diffusion tensor imaging and tractography parameters in pediatric spinal cord. This will help to understand maturation process in pediatric population and consequently will help for detection of diseased or injured spinal cord. |
| 1868 | Observing the evolution of MS plaques using SWI and DCS-PWI | |
1Department of Radiology,First Affiliated Hospital of Dalian Medical University, Dalian 116011, People's Republic of China, 2GE healthcare China, Beijing |
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In this study，we aim to study the morphologic and micro-hemodynamic changes of MS plaques using SWI and DSC-PWI. We selected twenty-one MS patients diagnosed by the McDonald criteria (Revised Edition 2010) underwent MR scans including SWI and dynamical susceptibility contrasted MR perfusion weighted imaging (DSC-PWI) at baseline. Then Results were obtained by follow-up and scan. The MS plaques shows decreased phase value and blood perfusion. The characteristic of MS plaque is hypointense foci with small veins and only “abnormal vessels” region predict early changes. |
| 1869 | The influence of rat strain on multi-parametric white matter metrics – a Tractometry study | |
1CUBRIC, Cardiff University, Cardiff, United Kingdom |
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White matter macrostructural organization and its microstructural composition are two complementary features that may help understand intact brain development, function and brain impairment. The Tractometry framework, which aims to characterise white matter by multi parametric MR metrics, was applied on 3 rat strains (Wistar, SD and Lewis). In this study we examined the impact of rat strain on microstructural features of white matter in the brain, which is suspected to origin from their genetics background. |
| 1870 | Targeted-FOV DWI can better depict the microemboli-induced renal lesions comparing to conventional full-FOV DWI | |
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, People's Republic of China, 2Philips Healthcare, Suzhou, People's Republic of China, 3College of Engineering, Peking University, Beijing, People's Republic of China, 4Department of Radiology, Peking University First Hospital, Beijing, People's Republic of China, 5Renal Division, Peking University First Hospital, Beijing, People's Republic of China, 6Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, People's Republic of China |
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DWI suffers from problems of severe geometric distortion and artifacts due to the susceptibility gradients and long echo train length (ETL), and the spatial resolution is quite limited due to the single-shot EPI acquisition scheme. This study investigates the utility of a targeted-FOV (TFOV) DWI technique in characterizing acute renal injure caused by microemboli injection in animal models. Compared with full-FOV DWI, the TFOV DW images show apparently higher image quality and better depiction of renal lesions. The advantage of TFOV DWI technique in characterizing microemboli-induced acute renal injure in is quite obvious. |
| 1871 | Diffusion MRI and magnetic resonance spectroscopy reveal microstructural and functional alteration in chronic mild stress exposed rat brains: A CMS recovery study | |
1Clinical Medicine, Center of Functionally Integrative Neuroscience, Aarhus, Denmark, 2Clinical Medicine, Translational Neuropsychiatry Unit, Risskov, Denmark, 3Advanced Imaging Research Center, Portland, OR, United States, 4Department of Physics and Astronomy, Aarhus, Denmark |
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Chronic mild stress (CMS) exposure leads to depression and other psychiatric disorder. Temporal changes post CMS exposure is still unclear. Present study employed CMS exposure on rats and utilised in-vivo longitudinal diffusion MRI and magnetic resonance spectroscopy (MRS) to reveal microstructural and functional alterations up to eight weeks post CMS exposure. Advanced diffusion kurtosis metrics have revealed significant alteration in stress sensitive regions, such as amygdala, hippocampus, prefrontal cortex and caudate putamen. MRS also showed significant metabolic alteration in ventral hippocampus, particularly on week1 post CMS exposure. Present finding could be useful in treatment of depression or similar disorders. |
| 1872 | Diffusion-weighted images super resolution via external and internal patch-based regularization | |
1School of Computer Science, Chengdu University of Information Technology, chengdu, People's Republic of China, 2College of Electronic Engineering, Chengdu University of Information Technology, chengdu, People's Republic of China |
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Super-resolution (SR) of diffusion weighted imaging (DWI) data is an ill-posed problem, which can be regularized by exploiting diverse priors learned from image patches. In this work, based on patch-based strategy of SR, we propose a new regularization method to reconstruct DW images, which integrates the sparse representation prior with dictionary learned from external image patches and non-local self-similarity prior learned from internal image patches. Meanwhile, in dictionary learning part, nonparametric Bayesian method is adopted to infer dictionary learning variables such as the size of the dictionary from data automatically. Experimental results demonstrate that the proposed method outperforms current methods in DWI reconstruction. |
| 1873 | Intravoxel incoherent motion (IVIM) diffusion-weighted imaging for response evaluation of hepatocellular carcinoma after resin- and glass-based radioembolization | |
1Radiology, University Hospital Bonn, Bonn, Germany |
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Intravoxel incoherent motion (IVIM) model-based analysis of diffusion-weighted imaging (DWI) is increasingly employed in oncologic imaging. Although first experiences with IVIM DWI for response analysis of hepatocellular carcinoma (HCC) after embolization therapies in general have recently been reported, response characteristics of specific treatment options are so far unknown. We describe differences in treatment response parameters of HCCs obtained by IVIM DWI in resin-radioembolization and glass-radioembolization. |
| 1874 | Changes of intravoxel incoherent motion (IVIM) diffusion-weighted imaging based parameters in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) creation – An initial analysis | |
1Radiology, University Hospital Bonn, Bonn, Germany |
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The creation of a transjugular intrahepatic portosystemic shunt (TIPS) influences hepatic blood flow dynamics. TIPS-related changes of diffusion-weighted imaging based intravoxel incoherent motion (IVIM) parameters at 1.5 T were investigated in liver parenchyma of cirrhotic patients. An increase of the IVIM perfusion fraction was found, indicating improved microvascular flow within the liver tissue after decompression of the portal vein. Diffusion parameters were not significantly influenced by TIPS-creation. |
| 1875 | White matter abnormalities of brain and cervical spinal cord in Hepatic Myelopathy patients: a diffusion tensor imaging study | |
1Department of Radiology, Xijing Hospital, The Fourth Military Medical University, shaanxi, xi'an, People's Republic of China, 2School of Life Sciences and Technology, Xidian University, People's Republic of China, 3the fourth military medical university, People's Republic of China, 4School of Life Sciences and Technology, Xidian University, xi'an, People's Republic of China |
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The prominent syndrome of HM such as spastic paraparesis is usually considered resulting from abnormal function of thoracic segments, nevertheless, the involvement of intracranial fibers and cervical spinal cord is not clear. In this study, we found a widespread and robust white matter tract abnormality in brain of HM and non-HM patients, without significant difference with cervical spinal cord. Our finding may help shedding light on the underlying pathological mechanism of HM. |
| 1876 | Signal behavior of Ultra-High-b radial DWI (UHb-rDWI) signal in different tract of the cervical spinal cord | |
1Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States, 2Department of Physics and Astronomy, University of Utah, Salt Lake City, UT, United States, 3Department of Neurology, University of Utah, Salt Lake City, UT, United States, 4Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States |
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The ultrahigh-b radial DWI (UHb-rDWI) technique is used to study the white matter disease in the spinal cord. The diffusion signal from the extra axonal (EA) space drops to noise level while that from the intra axonal (IA) space is almost constant at UHb region for the myelinated axons where the myelin layers prohibit the exchange of water molecules between IA and EA spaces. However for partially or unmyelinated axons, the diffusion signal from IA space is no longer constant. The signal behavior at UHb region could be used as a biomarker for the demyelination and axonal loss. |
| Exhibition Hall | Tuesday 16:15 - 18:15 |
| 1877 | Reliability of Single- and Multi-TI ASL measurements with a clinical product sequence | |
1Institute of Neurology, University College London, London, United Kingdom, 2Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 3Department of Information Engineering, University of Padova, Padova, Italy, 4Brain MRI 3T Mondino Research Center, C. Mondino National Neurological Institute, Pavia, Italy, 5Neuroradiology Unit, C. Mondino National Neurological Institute, Pavia, Italy, 6Department of Emergency Neurology, C. Mondino National Neurological Institute, Pavia, Italy, 7Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy, 8Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy, 9Department of Physics, University of Pavia, Pavia, Italy, 10Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, Italy, 11Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, Institute of Neurology, University College London, London, United Kingdom, 12Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, UCL Hospitals Foundation Trust, University College London, London, United Kingdom |
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Single-TI Arterial Spin Labeling (ASL) is sensitive to delayed arterial arrival time (AAT) of blood in the tissues. Multi-TI was introduced to overcome this limitation. Moreover, it allows estimating AAT that, therefore, can shed some light in the characterization of the brain haemodynamic processes. In this study, we compare the reliability of the multi-TI approach to the single-TI in a test-retest protocol. The sequence tested was the Siemens product sequence FAIR PASL with 3D-GRASE readout. Results show an overall good level of reliability both in single- and multi-TI, but also a possible sensitivity to the macro-vascular component in multi-TI data. |
| 1878 | Physiologically synchronized multi-module pulsed arterial spin labeled (SymPASL) MRI | |
1Physics and Astronomy, University of Southern California, Los Angeles, CA, United States, 2Electrical Engineering, University of Southern California, Los Angeles, CA, United States |
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Physiologically synchronized multi-module pulsed arterial spin labeling (SymPASL) involves pulsed labeling that is applied several times prior to pulsations in the arterial blood supply. Simulations and in vivo measurements in human kidneys demonstrate that SymPASL provides superior SNR and SNR efficiency compared to conventional flow-sensitive alternating inversion recovery (FAIR) ASL with a single labeling pulse. Simulations suggest that SymPASL provides comparable SNR and SNR efficiency to pseudo-continuous ASL (PCASL), with lower specific absorption rate (SAR). |
| 1879 | Hadamard-encoded Multi-delay PCASL: Should the Bolus Durations be T1-adjusted? | |
1Radiology, Stanford University, Stanford, CA, United States, 2GE Healthcare, Calgary, Canada |
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It has been hypothesized that in multi-delay arterial spin labeling (ASL), employing T1-adjusted labeling durations (LDs) should provide a more balanced signal-to-noise (SNR) across ASL signals, therefore improving the accuracy of the transit delay (TD) and perfusion estimation. However, this claim has not been thoroughly tested. In this study, we evaluated the effects on the TD and perfusion estimation using LDs both with and without T1-adjusted weighting, using the Hadamard-encoded multi-delay ASL sequence. Using Monte Carlo simulations and in vivo experiments, T1-adjusted weighting was more prone to noise and was likely to underestimate the TD and perfusion measurements compared to that without. |
| 1880 | Cerebral Blood Flow and Bolus Arriving Time Changes in Patients with Diabetes Detected by Multi-TI ASL | |
1Shandong Medical Imaging Research Institute, School of Medicine, Shandong University, Jinan, People's Republic of China, 2Laboratory of FMRI Technology (LOFT)，Mark & Mary Stevens Neuroimaging and Informatics Institute，Keck School of Medicine，University of Southern California (USC), LA, CA, United States, 3Siemens Healthcare, Erlangen, Germany, 4Siemens Healthcare, MR Collaborations NE Asia, Beijing, People's Republic of China |
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This study aimed to simultaneously measure cerebral blood flow (CBF) and bolus arriving time (BAT) in a cohort of subjects with type II diabetes, and compared the results with those of matched control subjects using a multi-TI 3D GRASE pulsed-ASL (PASL) sequence. The voxel-based analysis showed that the CBF and BAT values in patients with diabetes presented significant differences compared to healthy subjects, especially in some particular areas of the brain. These differences may be related to functional changes in patients with diabetes, which may have occurred before the onset of the symptoms. |
| 1881 | Estimation of Cerebral Blood Flow and Arterial Transit Time Using Partial Volume Corrected Multi-TI Arterial Spin Labeling Imaging | |
1Radiology, Wake Forest School of Medicine, Winston-Salem, NC, United States, 2Biomedical Engineering, Wake Forest School of Medicine, Winston-Salem, NC, United States, 3Clinical and Translational Sciences Institute, Wake Forest School of Medicine, Winston-Salem, NC, United States |
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A novel PVC algorithm using Multi-TI ASL, acquiring ASL images at multiple PLDs, has been proposed to estimate CBF and ATT in GM and WM separately. A 3D kernel was used to reduce noise sensitivity and improve the estimation power. The proposed method successfully estimated four perfusion parameters (GM CBF, GM ATT, WM CBF, and WM ATT) simultaneously, and may allow region- or voxel-based perfusion analyses in WM, as well as GM. |
| 1882 | Investigating the Sensitivity to Partial Volume Estimates of Partial Volume Correction for Single Postlabeling Delay Pseudo-continuous ASL | |
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, Copenhagen, Denmark, 3Department of Clinical Physiology, Nuclear Medicine and PET, Copenhagen University Hospital Rigshospitalet Blegdamsvej, Copenhagen, Denmark, 4St Hilda's College, University of Oxford, Oxford, United Kingdom |
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This work investigates the sensitivity of partial volume correction methods to partial volume estimates using single-PLD PCASL. Random and biased errors were applied to partial volume estimates to simulate the variabilities in tissue segmentation. The results have indicated that current partial volume correction methods trade off accuracy in spatial variations in CBF against sensitivity to noise and errors in the partial volume estimates. |
| 1883 | Regional Heterogeneity in Moyamoya Disease: Discovering Local Arterial Transit Time Information from Single-Delay Arterial Spin Labeling | |
1Radiology, Stanford University, Stanford, CA, United States |
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Arterial transit information provides valuable diagnostic information in steno-occlusive pathologies. We propose deriving transit information from the regional spatial heterogeneity (ReHet) of standard single-delay pseudo-continuous arterial spin labeling difference images. With image processing and machine learning, we demonstrate the potential of this technique in identifying regions with slow arterial flow in pre-operative Moyamoya disease patients. We investigate a selection of 7 different ReHet metrics, and identify trends that will inform better design of ReHet metrics and machine learning models. |
| 1884 | White matter cerebral blood flow in a large healthy cohort from the CARDIA study | |
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States, 3Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, United States |
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By analyzing cerebral blood flow (CBF) maps generated from arterial spin labeling (ASL) data averaged across 436 cognitively healthy middle-aged subjects from the CARDIA study, we characterized the CBF distribution in white matter. CBF is specifically decreased in periventricular regions in a pattern not reflective of partial volume effects as estimated from the structural MRI segmentation. White matter lesion frequency mapping based on Fluid Attenuated Inversion Recovery (FLAIR) images from the same cohort demonstrates that lesions tend to occur in regions where group averaged CBF is lowest. |
| 1885 | Arterial spin labelling measurements of cortical perfusion in multiple sclerosis show widespread reduced cortical metabolism | |
1Brain and Mind Centre, University of Sydney, Sydney, Australia, 2Neuroimmunology Clinic, Concord Hospital |
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Multiple sclerosis (MS) is primarily an inflammatory demyelinating disease of the central nervous system. However, there is also growing evidence that cortical dysfunction may also be associated with disability in MS. Few studies have investigated cortical cerebral perfusion in MS, and even fewer have utilised arterial spin labelling (ASL) MRI, which offers noninvasive quantitative assessment of cerebral function using endogenous contrast. ASL is an inherently low resolution imaging modality known to be affected by the partial volume (PV) effect, leading to an underestimation of grey matter (GM) perfusion. Decreases in GM perfusion could reflect neuronal loss or metabolic dysfunction; PV correction techniques allow decoupling of structure and function. It is hypothesized that reduced regional GM perfusion after PV correction reflects a genuine decreased tissue metabolism, rather than atrophy. |
| 1886 | Pseudo-continuous arterial spin labeling considerations in patients with sickle cell anemia | |
1Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 2Pediatrics - Division of Pediatric Neurology, Vanderbilt University Medical Center, Nashville, TN, United States, 3Medical Scientist Training Program, Vanderbilt University, Nashville, TN, United States |
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Pseudo-continuous arterial spin labeling (pCASL) MRI involves labeling of flowing arterial blood water; therefore, the flow velocity of the blood water affects the efficiency of pCASL labeling. This effect has been quantified in healthy subjects but has not been examined in adults with sickle cell anemia (SCA). In this study, we illustrate that cervical flow velocities are elevated in adults with SCA, resulting in a reduced pCASL labeling efficiency of 0.72, and errors associated with this phenomenon are more than twice as large as those associated with bolus arrival time variability when long post-labeling delays times are used. |
| 1887 | Improved reproducibility of longitudinal renal ASL perfusion measurements in children with chronic kidney disease using retrospective motion correction | |
1UCL Great Ormond Street Institute of Child Health, Developmental Imaging and Biophysics Section, London, United Kingdom, 2National Hospital for Neurology and Neurosurgery, Lysholm Department of Neuroradiology;, 3UCL Institute of Neurology, Department of Brain Repair and Rehabilitation |
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Arterial spin labelling (ASL) is a unique MR approach for quantifying tissue perfusion non-invasively. However, it is prone to motion-related artefacts which limit its application in the clinical domain, especially outside the brain. In this work, we combine a motion-insensitive ASL acquisition scheme with a specifically tailored retrospective motion correction pipeline. This enabled repeatable renal perfusion measurements to be obtained in the first ASL study in paediatric patients with moderate/severe chronic kidney disease. |
| 1888 | Simultaneous Multi-Slice Cardiac ASL | |
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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Cardiac arterial spin labeling (ASL) is a promising technique for the quantification of myocardial blood flow (MBF) and has been shown to detect clinically relevant changes in myocardial perfusion under vasodilator stress. However, current cardiac ASL techniques have limited spatial coverage because they cannot be repeated for multiple slices due to limited duration of pharmacologically induced peak stress (~3 min). In this work, we demonstrate the feasibility of using blipped CAIPI bSSFP for cardiac FAIR ASL. |
| 1889 | Measurement of lung perfusion using optimized pseudo-continuous arterial spin labeling of pulmonary arteries and fast True-FISP imaging at 3 Tesla | |
1Section on Experimental Radiology, University of Tübingen, Tübingen, Germany, 2Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 3Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany, 4Department of Diagnostic and Interventional Radiology, University of Tübingen, Tübingen, Germany, 5Department of Paediatric Cardiology, University of Tübingen, Tübingen, Germany, 6Department of Biomedical Magnetic Resonance, University of Tübingen, Tübingen, Germany |
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Pseudo-continuous-arterial-spin-labeling (pCASL) has been successfully applied in the brain and kidney providing high signal-to-noise-ratio. The aim of this study was to optimize pCASL for measurement of lung perfusion by optimized labeling of pulmonary arteries and fast signal acquisition. Effective labeling of pulmonary arteries was possible by ECG triggering and an appropriate orientation of the labeling plane. Sufficient signal from lung parenchyma was acquired by True-FISP imaging with TE=1ms. The presented method provides high quality perfusion images of the lung without applying intravenous contrast agents and offers diagnostic imaging of lung diseases such as pulmonary embolism and bronchial carcinoma. |
| 1890 | Quantification of mouse renal perfusion using arterial spin labeled MRI at 1 Tesla | |
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, 3Aspect Imaging, Shoham, Israel |
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The current work demonstrates the use of a 1 Tesla desktop MR system to study mouse kidney perfusion through arterial spin labeling (ASL) technique. The validity of the implementation was tested by (1) comparing obtained perfusion results with literature values for normal mice and (2) challenging the technique with mice treated with a blood vessel vasoconstrictor drug. Potential applications include easy assessments of disease state, metabolism, and tissue perfusion using a compact MR system. |
| 1891 | Validation of quantitative pre-clinical pseudo-continuous ASL in rat brain | |
1CRUK and MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom, 2FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 3Institute of Biomedical Engineering, Department of Engineering, University of Oxford, Oxford, United Kingdom |
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Guidelines for pre-clinical ASL are lacking. We propose MRI parameters for the use of pseudo-continuous ASL in rats. Carotid artery velocity was determined in three rat strains. Bloch simulations for ASL with this information and with parameters for pre-clinical scanners were used to determine the optimal width of the tagging plane required for blood inversion in this smaller species. The use of multiple post-label delays (PLD) in ASL-MRI generated blood arrival maps indicating that a PLD of 550ms was sufficient. Validation of CBF maps generated from ASL was performed using autoradiography, the current gold-standard technique for pre-clinical perfusion measurement. |
| 1892 | Combined 3D perfusion and diffusion MRI to phenotype the mouse brain: evaluation and application to a model of schizophrenia | |
1Grenoble Institut des Neurosciences, Université Grenoble Alpes, Grenoble, France, 2INSERM U1216, Grenoble, France, 3Bruker Biospin, Ettlingen, Germany, 4NeuroSpin, CEA Saclay, Gif-sur-Yvette, France |
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Perfusion and diffusion imaging both represent powerful tools in order to phenotype mouse models of brain diseases. Indeed, imaging cerebral blood flow (CBF) may be seen as a surrogate marker of brain metabolism while diffusion imaging provides the structural aspects of brain wiring. To evaluate the potential of combined CBF/Diffusion phenotyping, we evaluated the effect of knocking-out (KO) the microtubule-associated protein 6 (MAP6), which plays a critical role during the development of cerebral axonal tracts. Experiments were performed on homogeneous C57Bl6/129Sv mice using 3D pseudo-continuous Arterial Spin Labeling (pCASL) and 3D diffusion tensor imaging (DTI) at 9.4T. |
| 1893 | Multiphase pseudo-continuous ASL to image cerebral blood flow in mice at 9.4T | |
1Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom, 2Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom |
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Pseudo-continuous arterial spin labelling is regarded as the gold standard for clinical ASL, and can be improved in humans using multiphase sequences, but has not previously been implemented in mice. A multiphase pseudo-continuous ASL sequence to measure cerebral blood flow in mice was successfully implemented using respiratory triggering and optimisation of imaging readout, tag placement, labelling bolus duration, and post-label delay. Multiphase pseudo-continuous ASL is sensitive to changes in perfusion in an intracerebral glioma model. |
| 1894 | 3-Dimensional cerebral blood flow and transit time mouse brain mapping using Dynamic Arterial Spin Labeling (DASL) | |
1Grenoble Institut des Neurosciences, Université Grenoble Alpes, Grenoble, France, 2Inserm U1216, Grenoble, France, 3Bruker Biospin, Ettlingen, Germany |
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Measuring the arterial transit time (ATT) helps for the optimization and quantification of arterial spin labeling experiments. Moreover, ATT may provide information on potential underlying vascular pathologies. In preclinical perfusion studies, multiple 2D-slices are commonly acquired to measure perfusion. However, this readout limits the number of slices for which ATT can be measured accurately in rodents. In this study, we implemented and optimized a dynamic ASL labeling scheme with a 3D echo planar imaging (EPI) readout to simultaneously map cerebral blood flow, arterial transit time and tissue T1 in the mouse brain at 9.4T. |
| 1895 | Perfusion decrease during radiochemotherapy is not fully explained by volumetric gray matter changes | |
1PET center, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany, 2Brain Sciences Research Program, Sunnybrook Research Institute, Toronto, Canada, 3Department of Radiology, Academic Medical Center, Amsterdam, Netherlands, 4Rochester Institute of Technology, Rochester, NY, United States, 5Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, 6Department of Radiology, University Hospital Carl Gustav Carus, Technical University Dresden, Dresden, Germany, 7Department of Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technical University Dresden, Dresden, Germany, 8OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Dresden, Germany, 9German Cancer Consortium (DKTK), Dresden, Germany, 10German Cancer Research Center (DKFZ), Heidelberg, Germany, 11Institute of Radiooncology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany, 12Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Dresden, Germany |
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Radiochemotherapy in brain-tumor patients was shown to cause gray matter (GM) volume and cerebral blood flow (CBF) changes. The interaction of these two effects, however, remains unclear. Here, we investigated GM volume and ASL CBF changes and their interaction in the healthy hemisphere of 38 glioblastoma patients undergoing radiochemotherapy with Temozolomide. We found a statistically significant CBF decrease with dependence on the RT-dose. PV-corrected results indicated that, while to a certain extent the apparent CBF decrease measured by ASL is caused by GM atrophy, there still remain significant CBF changes that cannot be explained by structural changes alone. |
| 1896 | Feasibility and value of VTE-ASL in quantitative evaluation of unilateral renal embolism in rabbits | |
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, People's Republic of China, 2College of Engineering, Peking University, Beijing, People's Republic of China, 3Renal Division, Peking University First Hospital, Beijing, People's Republic of China, 4Department of Radiology, Peking University First Hospital, Beijing, People's Republic of China |
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Arterial spin labeling with variable echo time (VTE-ASL) is a perfusion imaging technique capable of noninvasive estimating of GFR. But the application of VTE-ASL in renal disease is still lagging behind. The goal of this study was to investigate the feasibility of GFR and RBF using VTE-ASL in evaluation of unilateral renal embolism in rabbits. Compared with normal kidney, embolism area has large decrease in GFR and RBF, and was confirmed by histological findings. |
| 1897 | Spatially localised measurements of oxygen extraction fraction using modified T2-relaxation-under-spin-tagging (SL-TRUST) | |
1FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom |
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An existing MR sequence, TRUST (T2-relaxation-under-spin-tagging), is adapted in order to obtain spatially localised T2 measurements for venous blood. T2-encoding, and hence determination of venous oxygenation, is achieved via localised encoding of the longitudinal magnetisation, that is then decoded in the sagittal sinus. Saturation pulses enable spatial localisation by removing signal from unwanted brain regions. Thus, hemispheric and global T2 measurements are acquired and compared. The delay between labelling and arrival of tagged venous blood in the sagittal sinus is evaluated and shown to increase in the presence of saturation pulses. |
| 1898 | Can We Trust TRUST Venous Oximetry in Sickle Cell Disease? | |
1Biomedical Engineering/ Cardiology, University of Southern California/ Children's Hospital Los Angeles, Los Angeles, CA, United States, 2Hematology, Children's Hospital Los Angeles, Los Angeles, CA, United States, 3Physiology and Biophysics, University of Southern California, Los Angeles, CA, United States, 4Cardiology, University of Southern California/ Children's Hospital Los Angeles, Los Angeles, CA, United States |
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In this work we derive a de novo T2b oximetry calibration curve for hemaglobin S containing red blood cells. We then compare predictions made by this calibration and existing T2b calibrations in 84 subjects in vivo using TRUST MRI. We found that predictions for venous oxygenation saturation and cerebral metabolic rate are widely different depending on the T2b calibration used for oximetry conversion. |
| Exhibition Hall | Tuesday 16:15 - 18:15 |
| 1899 | Optimization of Echo Times for CBV Measurements in the Arterial Input Function, Brain, and High-Grade Tumor Tissue using Error Analysis for DSC-MRI | |
1Barrow Neurological Institute, Phoenix, AZ, United States, 2Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, 3Medical College of Wisconsin, Milwaukee, WI, United States |
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This abstract demonstrates that the optimal TE for a single-echo DSC-MRI acquisition is 30-35 ms (without a preload) and 23-30 ms (with a standard full-dose preload) for a high-grade glioma population. Optimal TEs were calculated using error analysis on T2* values quantified during the first-pass of contrast agent using dual-echo DSC, and were shown to be the weighted-average of these values. Furthermore, we demonstrate that the optimal TE depends on tissue type (tumor/healthy tissue/AIF) and preload. |
| 1900 | Improving Simultaneous T1 and T2* Measurements for Dynamic Susceptibility Contrast MRI using a 3D Distributed Spirals Sequence | |
1Translational Bioimaging Group, Barrow Neurological Institute, Phoenix, AZ, United States, 2MR Technology Design Group, Barrow Neurological Institute, Phoenix, AZ, United States |
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Multi-echo (ME) DSC-MRI enables the simultaneous assessment of contrast-agent induced T1 and T2* changes, but its sensitivity to and the quantification of these T1 changes could be confounded by long TR and TE. Using simulations, we demonstrate that conventional 2D ME scans underestimate contrast agent concentration and DCE-MRI kinetic parameters. To solve this problem, we propose a 3D ME spiral acquisition that enables lower TRs and minimal TEs for improved T1 quantification and a range of echo times to main T2* sensitivity. |
| 1901 | Joint DCE- and DSC-MRI processing using the Gradient correction model | |
1Magnetic Resonance and Cryogenics, Institute of Scientific Instruments of the CAS, v. v. i., Brno, Czech Republic |
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The contribution presents a method for simultaneous processing of the DCE- and DSC-MRI perfusion data acquired using a multi-echo sequence. It is an extension of the sequential application of the so-called gradient correction model. In the sequential approach, relaxivity parameters are estimated from the DSC signal based on perfusion parameters calculated from the DCE signal. Here the perfusion and relaxivity parameters are estimated using an iterative alternating optimization strategy. The impact on accuracy and precision is tested on synthetic data. The results show that the suggested approach can yield a remarkable improvement, especially for noisy data. |
| 1902 | Correction of R2* Effects in Arterial Input Function of Fast Dynamic Contrast-Enhanced MRI for Accurate Cerebral Blood Flow Measurement | |
1Département de médecine nucléaire et radiobiologie, Centre d'imagerie moléculaire de Sherbrooke, Sherbrooke, QC, Canada, 2MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada |
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Signal loss resulting from $$$R_2^*$$$ effects is usually neglected in fast dynamic contrast-enhanced perfusion imaging. A new flow-compensated 3D RF-spoiled dual gradient echo sequence was designed to quantify the $$$R_2^*$$$ variation during a bolus injection of contrast agent and its effect on cerebral blood flow measurement. Moderate $$$R_2^*$$$ effects are found to be amplified by the non-linear relationship between signal ratio and concentration. This is shown to lead to substantial changes in peak arterial input function and measured cerebral blood flow. |
| 1903 | Improved Arterial Input Function Measurements Using Phase-versus-Time and Modified Look-Locker Inversion Recovery: Phantom Validation Study | |
1Carleton University, Ottawa, ON, Canada, 2Medical Imaging, The Ottawa Hospital, 3The Ottawa Hospital Research Institute, 4Radiology, The University of Ottawa, 5Division of Nuclear Medicine, The Ottawa Hospital, 6Siemens Healthcare, Erlangen, Germany, 7Cardiac PET Centre, University of Ottawa Heart Institute, 8Radiology, The Ottawa Hospital |
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Dynamic contrast-enhanced (DCE)-MRI is used to quantify organ perfusion abnormalities in many diseases, but is prone to errors. This study investigated the accuracy of a new method for measuring the arterial input function (AIF) in a flowing-water phantom using phase-versus-time measurements with pre- and post-DCE Modified Look-Locker Inversion Recovery (MOLLI) T1 measurements (Phase+MOLLI). The Phase+MOLLI technique provides an important improvement over previous methods since it avoids signal saturation and gives correct [Gd] values for the washout of the AIF. The Phase+MOLLI method was validated to be accurate, reproducible, and flow-insensitive so that it may be used for clinical DCE-MRI. |
| 1904 | Dynamic Susceptibility Contrast MRI at 7T: Tail Scaling Analysis and Inferences About Field Strength Dependence | |
1Department of Medical Radiation Physics, Lund University, Lund, Sweden, 2Department of Radiology (Adjunct), Johns Hopkins School of Medicine, Baltimore, MD, United States, 3Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 5Department of Diagnostic Radiology, Lund University, Lund, Sweden |
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In this study, a dynamic susceptibility contrast MRI (DSC-MRI) protocol for cerebral perfusion imaging at 7T was designed. With reduced contrast agent dose, the obtained perfusion maps showed the same visual appearance as seen at lower field strengths. In addition, a correction method was applied to obtain quantitative estimates of CBF and CBV in order to assess whether previous predictions of a field-strength dependence of the in vivo transverse relaxivity, leading to overestimated perfusion estimates, were supported. We concluded that assumptions of a field-strength dependence were plausible, based on observations of further elevated CBF and CBV estimates at 7T. |
| 1905 | Impact of Reference Time Curve Determination on the Correction of Contrast Agent Extravasation in Dynamic Susceptibility Contrast 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 investigated the influence of reference time curve determination on DSC leakage correction. Our findings suggested that the reference time curve obtained with inclusion of leaky tissue could lead a significantly different in K2, which supported that the probable error in lesion blood volume quantification with inaccurate automated segmentation process. |
| 1906 | Robust reference-region DCE-MRI analysis with a vascular component and two-fit analysis | |
1Medical Physics Unit, McGill University, Montreal, QC, Canada, 2Research Institute of the McGill University Health Centre, QC, Canada |
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The Extended Reference Region Model (ERRM) can quantify tumour perfusion without needing an arterial input function and includes a vascular term to account for the plasma volume. The addition of the vascular term also leads to larger variability in the estimated parameters. This study notes that one of the ERRM fitting parameters should be the same for all voxels. A two-fit approach is proposed that takes advantage of this constraint to reduce the number of fitting parameters from four to three. Evaluation in simulation and in-vivo found that the proposed two-fit approach resulted in a substantial decrease in variability for KTrans and kep estimates. |
| 1907 | Quantitative DCE-MRI Analysis using a Reference Tissue and AIF Tail | |
1Medical Physics Unit, McGill University, Montreal, QC, Canada, 2Research Institute of the McGill University Health Centre, QC, Canada |
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The reference region model can quantify tumour perfusion without needing an arterial input function (AIF) and provides relative estimates, i.e. KTrans/KTrans,RR and ve/ve,RR which are usually converted to absolute KTrans and ve by using literature-based values for KTrans,RR and ve,RR. However, this approach fails to account for inter-patient variability. This study proposes a method that uses the Reference Region and AIF Tail (RRIFT) to estimate patient-specific KTrans,RR and ve,RR. The AIF tail is the post-peak part of the AIF and is easier to measure than the complete AIF. Evaluation in simulation and in-vivo showed that RRIFT provides comparable results to Tofts model, and even outperforms the Tofts model at slower temporal resolutions. |
| 1908 | Feasibility and value of View-shared Compressed Sensing combined fast DCE-MRI in quantitative evaluation of unilateral renal embolism in rabbits | |
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, People's Republic of China, 2College of Engineering, Peking University, Beijing, People's Republic of China, 3Department of technical research and development, Instrumentation Technology and Economy Institute, Beijing, People's Republic of China, 4Department of Radiology, University of Cambridge, United Kingdom, 5Interventional radiology and vascular surgery, Peking University First Hospital, Beijing, People's Republic of China, 6Department of Radiology, Peking University First Hospital, Beijing, People's Republic of China |
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Dynamic-contrast enhanced MR imaging is widely employed as a clinical tool in kidney imaging and renal function measurements. Some novel works have been made in improve temporal resolution. In this work, we adopt a 3D Cartesian MRI with compresses sensing and variable view sharing sequence to explore its evaluation in renal embolism assessment. GFR was calculated and renal embolism was confirmed by histological results. Fast DCE-MRI is a promising method for renal embolism diagnose. |
| 1909 | Comparison of (k,t) sampling schemes for DCE MRI pharmacokinetic parameter estimation | |
1Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States |
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We demonstrate an approach to evaluate and compare (k,t) sampling patterns for DCE-MRI. We compute Cramér-Rao lower bounds on the variance of pharmacokinetic (PK) parameter estimates, using pathologically- and anatomically-realistic digital reference objects. The framework allows for the optimization of sampling patterns independent of any specific estimator. We apply this framework to a 2D reference object for four sampling patterns: keyhole, TRICKS, lattice, and golden angle sampling. It is shown that TRICKS, lattice, and golden angle sampling enable low variance estimation for low undersampling factors. Out of these, lattice sampling keeps variances lowest with increasing undersampling factors. |
| 1910 | Influence of parameter initial values on DCE parameter estimates in pharmacokinetic modeling: a simulation study | |
1German Cancer Consortium (DKTK), Heidelberg, Germany, 2Translational Radiation Oncology, Heidelberg Institute of Radiation Oncology (HIRO), German Cancer Research Center (DKFZ), Heidelberg, Germany, 3Department of Radiation Oncology, Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg University Hospital, Heidelberg, Germany, 4National Center for Tumor Diseases (NCT), Heidelberg, Germany, 5Software development for Integrated Diagnostics and Therapy, German Cancer Research Center DKFZ, 6Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich |
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In pharmacokinetic analysis of DCE-MRI data, the choice of initial parameter values for fitting has been reported to have a significant impact on the outcome of the optimization and hence, on parameter estimates. In this study, we investigated the influence of initial values by fitting simulated concentration time curves with varying combinations of initial parameters, using the two compartment exchange model. The resulting parameter estimates were visualized and compared to the true values, used for simulation, by means of relative errors. Results showed that the choice of initial values has little influence on the precision of the pharmacokinetic analysis. |
| 1911 | Nested tracer-kinetic model-based DCE-MRI reconstruction from under-sampled data | |
1Electrical Engineering, University of Southern California, Los Angeles, CA, United States, 2Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 3GE Healthcare, Calgary, Canada |
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We propose a novel nested tracer-kinetic (TK) model based constrained reconstruction method for DCE-MRI reconstruction from under-sampled data. This approach models the concentration time profiles as a sparse linear combination of temporal bases constructed from TK models of varying complexity. Subspaces from the models of plasma volume, Patlak, and the extended-Tofts are constructed. A spatial mask determining the TK model complexity at every pixel location is derived. Reconstruction involves iteration between data consistency and pixel wise projection of the concentration profiles on one of the three subspaces. We demonstrate its utility in retrospective under-sampled reconstruction of brain tumor DCE-MRI datasets. |
| 1912 | Measurement of Murine Single-Kidney Glomerular Filtration Rate using Dynamic Contrast Enhanced MRI | |
1Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, United States, 2Division of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, United States |
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A method for noninvasive assessment of mouse glomerular filtration rate (GFR) using dynamic contrast enhanced MRI (DCE-MRI) was developed and validated. The kinetics of gadolinium in the abdominal aorta and two kidneys were measured using a snapshot fast low angle shot based T1 mapping method with a temporal resolution of 1 s. A modified bi-compartmental model was used for quantification of GFR by a least-squares fitting. As a reference standard, GFR was also measured using FITC-inulin clearance. Single-kidney GFR measured from both methods showed a good agreement, suggesting the proposed DCE-MRI method provides an accurate measurement of murine single-kidney GFR. |
| 1913 | Patlak analysis of dynamic gadoxetic acid-enhanced MR imaging is an effective and simpler alternative to compartmental pharmacokinetic modelling for assessing liver function | |
1CRUK Cancer Imaging Centre, Division of Radiotherapy and Imaging, Institute of Cancer Research, Sutton, United Kingdom, 2Departent of Radiology, Royal Marsden NHS Foundation Trust, Sutton, United Kingdom, 3Siemens Healthcare, Erlangen, Germany |
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Liver perfusion and function can be assessed using gadoxetic acid combined with DCE-MRI imaging and pharmacokinetic (PK) modelling. Whilst compartmental PK models give a good account of the contrast changes over the first five minutes of enhancement, the Patlak graphical approach is a simpler alternative that is more easily implemented. Patlak evaluation requires the specification of a delay time after which the initial transients in the uptake curves have decayed, so the purpose of this abstract is to present a preliminary evaluation of the sensitivity of liver uptake rate estimates to the Patlak delay time. |
| 1914 | Vastly accelerated linear least squares fitting with numerical optimization for dual delay compensated quantitative liver perfusion mapping | |
1Cornell University, Ithaca, NY, United States, 2Weill Cornell Medicine, New York, NY, United States |
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Accurate liver perfusion quantification requires correction for dual arterial and portal venous input delays, but such dual delay correction in current nonlinear perfusion methods is computationally too expensive to apply in perfusion mapping. We realize that the kinetic equation is a linear differential equation that would allow fast linear processing. Accordingly, we propose to use linear least squares (LLS) fitting to this kinetic equation with fast conjugate gradient search for processing dynamic contrast enhanced MRI data. Our proposed LLS vastly (~300 times) accelerate computation in perfusion quantification, enabling for the first time accurate liver perfusion mapping with dual delay corrections. |
| 1915 | Absolute Quantification of Brain Perfusion using Golden Angle Compressed Sensing DCE-MRI | |
1Institute of Scientific Instruments of the CAS, Brno, Czech Republic, 2Department of Telecommunications, Brno University of Technology, Brno, Czech Republic |
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A DCE-MRI method for absolute quantification of cerebral blood flow (CBF) and volume (CBV) and vessel permeability surface area product is presented. It is based on L+S compressed sensing, the two-compartment exchange model (2CXM) and blind deconvolution estimation of the arterial input function. The method is evaluated on data from a healthy rat. |
| 1916 | Parameters From Dynamic Contrast-Enhanced Magnetic Resonance Imaging Are Biomarkers Predicting Response after Radiation to Brain Metastases | |
1National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China, 2GE HealthCare, MR Research China, Beijing, People's Republic of China |
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Dynamic contrast-enhanced (DCE) MRI provides additional information regarding blood-brain barrier integrity, and Ktrans is directly proportional to the level of permeability of the blood-brain barrier. In our study, we found demonstrates that SRS of cerebral metastasis is associated with a reduction of Ktrans values in the early post-treatment period. DCE-MRI derived parameters of Ktrans may be a promising imaging biomarker of tumor aggressiveness. |
| 1917 | Quantification of tracer kinetic and hemodynamic parameters of human breast tumor and fibro-glandular tissue using DCE-MRI data | |
1Centre for Biomedical Engineering, Indian Institute of Technology Delhi, Delhi, India, 2Fortis Memorial Research Institute, Gurgaon, India, Delhi, India, 3Department for Biomedical Engineering, AIIMS Delhi, New Delhi, India. |
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Objective of current study was to develop a framework for computing tracer kinetic parameters using GTKM model and hemodynamic parameters using first pass analysis of human breast tissue for characterizing of breast lesion; and also differentiation of the histological grade II and III of breast cancer. A significant difference between benign, malignant and fibroglandular tissues; and also between grade II and III of breast cancer were observed. |
| 1918 | The Vanishing Shutter-Speed Limit | |
1Section on Quantitative Imaging and Tissue Sciences, DIBGI, NICHD, National Institutes of Health, Bethesda, MD, United States, 2Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States |
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Dynamic-contrast-enhanced MRI (DCE-MRI) has been widely used to characterize microvasculature permeability. Recently, it was shown to reveal metabolic activity using the shutter-speed pharmacokinetic paradigm (SSP), in which steady-state intra/extracellular water exchange kinetics was incorporated into DCE-MRI data analysis. Interesting insights into DCE-MRI signals come from modeling the extravascular tissue MR signal. The questions addressed here are, “When can extravascular 1H2O longitudinal magnetization recovery from inversion/saturation still be described by a single-exponential process, and when can the intra/extracellular water exchange kinetics be accurately determined?” |
| 1919 | Whole Brain Dynamic Contrast-Enhanced MRI Study of Blood-Brain Barrier Disruption in Systemic Lupus Erythematosus Patients: Implications on the Choice of Tracer Kinetic Model | |
1Clinical Imaging Research Centre, Singapore, Singapore, 2Division of Rheumatology, National University Hospital, Singapore |
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Current evidence suggests that blood-brain barrier (BBB) integrity is one of the potential biomarkers to diagnose neuropsychiatric systemic lupus erythematosus patients. We use DCE MRI and performed tracer kinetic analysis using both a distributed parameter (DP) model and the modified Tofts (MT) model. More Leaky BBB in SLE patients with anti-NR2 in their sera than the controls was detected by the permeability related parameters from both models. However, Ktrans of MT model, which is commonly used in DCE MRI of cancer studies, might be less reliable than DP model permeability parameters in this study. |
| 1920 | Feasibility and Value of Quantitative Dynamic Contrast Enhancement MR imaging in the Evaluation of Lymphoma and Inflammatory Pseudotumor in the Orbit | |
1Department of Radiology, Beijing Tong Ren Hospital,Capital Medical University, Beijing, People's Republic of China, 2GE Healthcare, MR Research China, Beijing, People's Republic of China |
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This work assessed the feasibility of quantitative parameters derived from dynamic contrast enhanced MR imaging (DCE-MRI) and evaluated the value of quantitative dynamic contrast enhanced MR imaging in the differential diagnosis between lymphoma and inflammatory pseudotumor in the orbit. From the results we can see that it is feasible that quantitative parameters of DCE-MRI can be applied in the differential diagnosis between lymphoma and inflammatory pseudotumor in the orbit. Thus, it can probably be used as imaging biomarkers to predict prognosis and aggressiveness of orbital lymphoma. |
| 1921 | Assessment of hydrodynamics and T2 alterations in spontaneously hypertensive rat under short-term hyperhydration | |
1Biomedical Engineering and Environmental Science, National Tsing Hua Unerversity, Hsinchu, Taiwan, 2Nuclear Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan, 3Graduate Institute of Applied Physics, National Chengchi University, Taipei, Taiwan, 4Department of Radiology, Taipei Medical University Hospital, Taipei, Taiwan |
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With a fluid infusion of 2% of body weight in the D2O perfusion imaging experiment, the tissues are expected in a hyperhydration state. In this study, we conduct both D2O and H2O infusion experiments on spontaneously hypertension rat (SHR). Fast and slow flow of brain were analyzed by a two-compartmental parallel model. Pre- and post-infusion T2 maps were acquired. The slow flow matched the T2 prolonged regions, which could be due to the CSF production and flow. |
| 1922 | Feasibility study of a Dialyzer as a multi-compartment Perfusion Phantom for microvascular tracer kinetic Modelling | |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany |
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Dynamic contrast enhanced MRI combined with tracer kinetic modelling allows for the determination of quantitative perfusion parameters. To achieve standardized examinations and data analysis, phantoms are employed to investigate the reproducibility of perfusion parameters by imitating tissue on capillary level. In this study we used a dialysis filter with a semipermeable membrane of the fibers which enables the simulation of two compartment kinetics and can thus serve as imitation of capillaries and interstitium which might be closer to the anatomical conditions. |
| 1923 | Feasibility of using Active Contrast Encoding (ACE)-MRI for Assessment of Tumor Treatment Response | |
1Center for Advanced Imaging Innovation and Research (CAI2R), Dept. Radiology, NYU School of Medicine, New York, NY, United States |
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Active Contrast Encoding MRI (ACE-MRI) is a recently proposed method to conduct DCE-MRI experiment without the need to perform separate T1 and B1 measurement. The purpose of this study is to further investigate the feasibility of using the ACE-MRI method for evaluation of tumor treatment response in a mouse model of breast cancer. The results of the ACE-MRI method were compared with conventional DCE-MRI data analysis with separately measured T1 maps. Our preliminary results demonstrate that the ACE-MRI method can be used to evaluate tumor treatment response reliably. |
| Exhibition Hall | Tuesday 16:15 - 18:15 |
| 1924 | Accurate Tissue Oxygen Level-dependent MRI with true T1-weighted signal | |
1Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, Korea, Republic of, 2Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Korea, Republic of, 3Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of |
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Tissue oxygen level dependent (TOLD) MRI utilizes that T1 is directly related with tissue pO2. TOLD MRI is acquired by gradient echo based with a minimized TE. However, T2* contribution may not fully be suppressed. Here, we investigated the modulations of longitudinal and transverse relaxation times with oxygen challenge (OC) and compared TOLD signals from FLASH, UTE, and TSE at 7 T and 15.2 T. At both magnetic fields, T2 did not change with tissue pO2 while T1 did. Spin echo and UTE appear to reflect true pO2 levels due to invariability in T2 during OC and minimized T2* with ultrashort TE, respectively. |
| 1925 | Direct Assessment of Magnetization Transfer Effects with T1 qMRI | |
1Boston University, Boston, MA, United States |
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Purpose: To measure inaccuracies on T1 qMRI caused by magnetization transfer effects that are inherent to MRI pulse sequences. Methods: The mixed-TSE pulse sequence was used at several RF power levels to image a series of agarose gels, sucrose solutions, and Gd solutions. Results: Measured T1s are increasingly underestimated as a function of increasing semisolid pool size and RF power level. Conclusion: Uncorrected magnetization transfer effects can cause large underestimation of T1 measurements in tissue imaged with RF intensive pulse sequences. This work could have implications for the design of more accurate qT1 mapping algorithms. |
| 1926 | MR Contrast Effects of Intrinsically Gd-chelated Melanin Nanoparticles at 1.5 and 11.7 Tesla | |
1Radiology, Northwestern University, Chicago, IL, United States |
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The development of polymeric contrast agents exhibiting a high MR relaxivity has been achieved using bio-inspired metal chelating melanin nanoparticle (Mel NP) synthesized with dopamine or L-3,4-dihydroxyphenylalanine (L-DOPA). In here, we described our simple one-pot synthesis to prepare new Gd chelated Mel NP and their specific features of efficient MR T1 imaging along with their high intrinsic Gd chelation efficiency. |
| 1927 | Effect of vendor specific formalin composition and concentration on post-mortem MRI of human brain tissue | |
1Department of Neurology, Medical University of Graz, Graz, Austria, 2Department of Neuropathology, Institute of Pathology, Medical University of Graz, Graz, Austria, 3Department of Pathology, Medical Faculty, Otto-von-Guericke-University, Magdeburg, Germany |
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Formalin fixation is common procedure to prevent tissue autolysis by crosslinking proteins. Not unexpectedly this affects the relaxation properties of the tissue. In addition, quantitative relaxation time constants of formalin fixed brain tissue show a broad variation across different studies. To investigate the contribution of the formulation of formalin to this variability we investigated MR relaxation times of pure formalin solutions from different vendors and the effect of formalin concentration on MR relaxation times of fixed brain tissue. Our results showed a strong variation of relaxation times depending on the concentration used and more importantly on the vendor specific composition of the formalin solutions. |
| 1928 | Relaxation time shortening by oxygen molecules: Strong enhancement in a viscous solution with cellular viscosity | |
1Graduate School of Health Sciences, Hokkaido University, sapporo, Japan, 2Faculty of Health Sciences, Hokkaido University, sapporo, Japan |
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Since oxygen molecules are paramagnetic, they shorten the relaxation time as well as gadolinium contrast medium. The effect of relaxation time shortening by the paramagnetic substance is enhanced with an increase in viscosity of the solution as in the cell. We investigated the longitudinal and transverse relaxivities of oxygen in viscous solution with cellular viscosity and clarified that the relaxation time shortening by oxygen molecules strongly increases with an increase in viscosity. This effect of oxygen in the cell may be visible by using pulse sequences that enhance the signal from the cellular proton. |
| 1929 | Characterization of the Four Pool Model in formalin-fixed sheep's brain using NMR spectroscopy | |
1Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 2Radiology, University of British Columbia, Vancouver, BC, Canada |
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Despite its importance, T1 relaxation in brain and spinal cord is not well understood. The Four Pool Model gives a fundamental framework for its understanding in white and grey matter tissue. In this work, we characterize the Four Pool Model for the first time in formalin-fixed sheep's brain using NMR spectroscopy. We find this is a suitable system, and our results are consistent with previous studies: T1 is multi-exponential and the values measured result from a convolution of pure relaxation and exchange processes. |
| 1930 | Transverse relaxation of cerebrospinal fluid depends on glucose concentration | |
1National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States |
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Brain relaxometric properties are widely used by the NMR community. While brain tissue relaxivities are well established, much less work has been done on CSF relaxivities. To clarify this point, we characterized the CSF relaxometric properties at various field strengths in vivo and in vitro. Our results suggest that low field is more optimal to quantify CSF T2 due to smaller residual gradients. There is a significant difference between in vitro CSF T2 vs saline T2 that is mostly explained by the glucose relaxivity. This finding was confirmed in vivo, opening the possibility of studying glucose regulation of CSF at the resolution of MRI.
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| 1931 | Origin of Dipolar Effects - Achilles Tendon at 3T and 11.7T. | |
1Radiology, Univ. of California, San Diego, San Diego, CA, United States |
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We examined the MR image appearance of human Achilles tendon as a function of orientation to the B0 field at 3 T and 11.7 T. Images were registered and displayed a remarkable similarity in the fine discernable structural features at both field strengths. Residual dipolar effects are responsible for the contrast on these images, rather than frequency changes that scale with magnetic field. |
| 1932 | Effect of T1 on Multi-echo Gradient Echo based Myelin Water Fraction | |
1Yonsei University, Seoul, Korea, Republic of, 2Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea, Republic of |
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Myelin Water Fraction uses the property that myelin water has shorter T2* relaxation time compared to axonal/extra-cellular water. Previous studies found that not only the T2/T2* relaxation time but also the T1 relaxation time is difference between these compartments. The T1 relaxation time of myelin water is known to be affected by the cross-relaxation therefore the term “apparent T1” is considered more accurate. In this study, we analyze the effect of this ‘apparent’ T1 in mGRE based MWF. Our results show that the MWF estimation is dependent on the differential T1 of different compartments. T1 effect on the MWF can makes overestimation error. Using the low flip angle could reduce the this error, but it gives rise to insufficient SNR on MWF. Also, increasing TR could be another choice for reducing estimated error, but it leads to inefficient scan time. Thus, GRE-MWF is needed to compensated T1 effect for accurate quantification. |
| 1933 | Development and Systematic Analysis of 2D and 3D GRE Myelin Water Imaging | |
1Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of, 2Biomedical Engineering, Hankuk University of Foreign Studies, Seoul, Korea, Republic of |
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In this study, we developed |
| 1934 | Making Myelin Water Imaging Mainstream: Multi-site and Multi-vendor Reproducibility | |
1Medicine, Neurology, University of British Columbia, Vancouver, BC, Canada, 2Electrical Engineering, Polytechnique Montréal, Montreal, QC, Canada, 3Pediatrics, University of British Columbia, Vancouver, BC, Canada, 4Radiology, University of British Columbia, Vancouver, BC, Canada, 5Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, 6Radiology, University of Manitoba, Winnipeg, MB, Canada, 7Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of |
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Myelin water imaging (MWI) is a quantitative T2 relaxation-based MRI technique, measuring the amount of myelin in the central nervous system. We investigated the reproducibility of MWI using GRASE with 3T MR scanners from two different vendors at two sites. Using stimulated echo correction, differences in the refocusing flip angle profile between the two sites were effectively corrected for and myelin estimates between the two sites were found to be highly correlated (slope=1.12, R2=0.96). This is the first multi-vendor and multi-site reproducibility study of MWI using GRASE, encouraging future multicenter MWI studies. |
| 1935 | Spatial distribution of myelin concentration in healthy volunteers measured in GRE myelin water imaging, ViSTa myelin water imaging, quantitative MT and DTI | |
1Department of Electrical and Computer Engineering, Seoul National University, Seoul, Korea, Republic of, 2Department of Biomedical Engineering, Hankuk University of Foreign Studies, Yongin, Korea, Republic of |
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This study investigated the spatial distribution of several myelin imaging methods. Myelin water fraction in GRE-MWI, apparent MWF in ViSTa-MWI, fractional pool size (F) in qMT, MT saturation, MT ratio, and FA in DTI were compared for their spatial distribution in white matter. Strong correlations were measured particularly between GRE-MWI and ViSTa-MWI and also among MT contrasts. FA showed least correlations with the other parameters. |
| 1936 | Measurement of T1, T2, and flip angle with double-angle inversion-recovery balanced steady state free precession with application to imaging the eye | |
1Research Imaging Institute and Ophthalmology, University of Texas Health Science Center, San Antonio, TX, United States, 2Research Imaging Institute, University of Texas Health Science Center, San Antonio, TX, United States, 3Biomedical Engineering, University of Texas at San Antonio, San Antonio, TX, United States |
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Fast measurement of T1 and T2 can be made with high signal to noise using inversion-recovery Look-Locker (LL) bSSFP. However, the LL-bSSFP signal is dependent on the flip angle, which must be known for accurate T1 and T2 calculation. In this study we investigated methods to additionally map and correct for the flip angle with the acquisition of two LL-bSSFP scans with two different flip angles, avoiding the need for a separate flip angle mapping protocol. Simulations and scans of the eye showed that T1, T2, and the flip angle could be measured with the double-angle LL-bSSFP method. |
| 1937 | Quantitative relaxation time mapping of axillary lymph nodes and recommended parameters for 3T lymphatic node substructure imaging | |
1Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, 2Physical Medicine and Rehabilitation, Vanderbilt University Medical Center, Nashville, TN, United States, 3Vanderbilt Dayani Center for Health and Wellness, Nashville, TN, United States, 4Neurology, Vanderbilt University Medical Center, Nashville, TN, United States, 5Psychiatry, Vanderbilt University Medical Center, Nashville, TN, United States, 6Physics and Astronomy, Vanderbilt University, Nashville, TN, United States |
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A lack of MRI methods exist that are designed with sensitivity to the lymphatics, even though components of the lymphatic system have been discovered in every major organ system of the body and likely play an understudied role in disease. In this work we performed quantitative relaxation time mapping in axillary lymph node substructures, the cortex and hilum, for the first time at 3 Tesla and used these values to optimize structural imaging parameters for the lymphatics. Knowledge of fundamental MR parameters in the lymphatics is the first step to developing novel imaging sequences that exploit lymphatic tissue in vivo. |
| 1938 | Relaxation Times and Magnetic Susceptibility of Human Umbilical Cord Blood at 3 Tesla | |
1Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, 2Department of Obstetrics and Gynecology, Mount Sinai Hospital, Toronto, ON, Canada, 3Department of Pediatrics and Diagnostic Imaging, University of Toronto, Toronto, ON, Canada, 4Division of Cardiology, The Hospital for Sick Children, Toronto, ON, Canada, 5Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON, Canada, 6Department of Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, ON, Canada |
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With an increasing proportion of fetal cardiovascular MRI scans being performed at 3 Tesla, there is growing need for an accurate calibration, which characterizes relationships between MRI properties (T1, T2, susceptibility) and blood properties (oxygen-saturation, sO2 and hematocrit, Hct) at 3T. Accordingly, relaxometry measurements were performed at 3T on cord blood specimens (N=89) with a broad range of hematocrits (0.09<Hct<0.82) and oxygen-saturations (7%<sO2<100%). We also measured fetal blood susceptibility, which, to our knowledge, has never been reported. The data were effectively described by a simple, two-compartment model for blood. |
| 1939 | Hemodynamic response to respiratory challenge evaluated by dynamic R2’ imaging: application for acute renal ischemia caused by microsphere-induced renal artery embolism | |
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, People's Republic of China, 2interventional radiology and vascular surgery, Peking University First Hospital, Beijing, People's Republic of China, 3College of Engineering, Peking University, Beijing, People's Republic of China, 4Philips Healthcare, Suzhou, People's Republic of China, 5Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, People's Republic of China, 6Department of Radiology, Peking University First Hospital, Beijing, People's Republic of China |
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The clinical use of iodinated or gadolinium contrast agents for renal hemodynamic imaging is limited in the presence of renal dysfunction due to its increased risks of exacerbating renal damage. Therefore, we performed a modified HRI technique with a specific-designed magnetic-susceptible sequence that could separate R2’ from the BOLD signals in a unilateral microemboli-induced AKI model. The results show that R2’ in normal or less affected regions reduced after carbogen challenge, while the R2’ in the most affected lesions increased significantly. The dR2’ map could indicate the most affected areas accurately confirmed with the final anatomic T2w image. |
| 1940 | Determination of Oxygenation Extraction Fraction for People with Sickle Cell Anemia using Calibration Model Specific to SCA Blood | |
1Department of Radiology, 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, 3Division of Pediatric Hematology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4Division of Hematology, Duke University, Durham, NC, United States |
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For the blood T2-based MRI oximetry methods, the calibration model to convert blood T2 to blood oxygenation (Y) is critical to calculate the brain oxygen extraction fraction (OEF). Here, we established a calibration model specific to people with sickle cell anemia (SCA) using in vitro blood T2 measurements on SCA blood samples under various conditions. The results show that the use of calibration models based on normal blood underestimate Y, and thus overestimate OEF, for individuals with SCA. Using a fast T2 protocol to measure oxygenation in the internal jugular vein (IJV), the whole-brain OEF values of individuals with SCA were determined and compared with healthy volunteers. |
| 1941 | Cause of death or caused by death: Differentiation of thromboemboli and post-mortem clots using quantitative MRI | |
1Ludwig Boltzmann Institute for Clinical Forensic Imaging, Graz, Austria, 2BioTechMed, Graz, Austria, 3Institute of Pathology, Medical University Graz, Graz, Austria, 4Institute of Medical Engineering, Graz University of Technology, Graz, Austria, 5Institute of Forensic Medicine, Medical University Graz, Graz, Austria |
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MRI is increasingly being used in post-mortem examinations to assist in determining cause of death. Post-mortem changes, such as the formation of post-mortem clots (PMC), present a specific challenge in forensic imaging where differentiation between these alterations and pathological findings (e.g. thromboemboli) is essential. This work imaged thromboemboli and PMC samples collected during autopsy at 3T. K-means clustering was applied to analyse voxel-grouping in the resulting quantitative data. Clusters specific to a single clot type were identified in 3 of the 4 samples. Preliminary findings indicated the existence of at least one common differentiating cluster specific to PMC. |
| 1942 | An optimised 2D MPRAGE sequence for T1 contrast in the fetal brain: application to slice to volume reconstruction and multiband acceleration | |
1Division of Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom, 2Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, United States |
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Ultrafast single-shot T2 weighted images are common practise in fetal MR exams. However, there is limited experience with fetal T1 acquisitions. In this study, a 2D gradient echo sequence with an adiabatic inversion was optimized to be robust to fetal motion and to preserve contrast. We also explore slice to volume registration and super resolution reconstruction methods to enhance the resolution, and we show pilot data from a multiband accelerated version of the above-mentioned sequence. |
| 1943 | Combination of MT and R2* measurements to distinguish between contributions of semisolids and iron to R1 | |
1Advanced MRI Section, LFMI, NINDS, National Institutes of Health, Bethesda, MD, United States, 2Center for Functional and Molecular Imaging, Georgetown University Medical Center, Washington, DC, United States |
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In human brain, the apparent longitudinal relaxation rate (R1) primarily originates from magnetization transfer (MT) effects associated with the macromolecular 1H-proton fraction (f), although in some regions the iron concentration may contribute as well (Rooney, 2007). To quantify their relative contributions at 7 T, we measured f and R1 of water protons (R1,WP) corrected for MT effects using a pulsed, transient MT approach (van Gelderen, 2016). The iron concentration was taken from literature and correlated with R2*. The results indicate that the combination of R2* and MT measurements may provide a sensitive means to quantify R1,WP, f and iron concentration. |
| Exhibition Hall | Tuesday 16:15 - 18:15 |
| 1944 | On the feasibility of synthetic sodium MRI based on tissue conductivity | |
1INM4, JARA-Faculty of Medicine, RWTH Aachen University, Aachen, Germany, Juelich, Germany, 2Institute of Neuroscience and Medicine-4, Forschungszentrum Juelich, Juelich, Germany |
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The recently proposed magnetic resonance electrical property tomography opens new opportunities for sodium ion characterisation. In this study, a model was built by measuring electrical conductivity and sodium MRI in different saline solutions. We exploit this interdependence with additional temperature correction to build a synthetic sodium brain map based on in vivo electrical conductivity. The results were compared to sodium MRI measurements. A statistically significant Pearson correlation (p<0.001; r=0.43) was observed between the two modalities while Bland-Altman analysis revealed discrepancies between them with a mean difference ~4mMol/L in whole brain. The proposed approach facilitates tissue sodium extraction. |
| 1945 | Advanced 3D simultaneous conductivity and susceptibility imaging with mitigation of nonlinear phase evolution effect. | |
1Electrical &Electronic Engineering, Yonsei University, Seoul, Korea, Republic of |
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Simultaneous Quantitative conductivity and susceptibility mapping (QCSM) can acquire both 3D conductivity and 3D susceptibility map with a single scan 3D multi-echo GRE sequence. However, error occurs due to nonlinear phase evolution in some regions producing false values especially for conductivity. In this study, we analyzed this effect and propose a way to mitigate this effect. |
| 1946 | Evaluation of dual-echo EPI for in-vivo current mapping in individual subjects during transcranial Direct Current Stimulation | |
1Biomedical Engineering, University of California Los Angeles, Los Angeles, CA, United States, 2University of Southern California, CA, United States, 3Biomedical Engineering, City College of New York, NY, United States |
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Transcranial Direct Current Stimulation (tDCS) is a neuromodulation technique that uses milliampere currents to modulate cortical excitability. Although tDCS has been shown to treat clinical symptoms and improve cognition, the distribution of tDCS currents in the brain remains unknown. Here we show a MRI technique that measures a component of the magnetic field induced by tDCS currents in-vivo. Experimental data acquired using this technique is compared to model-based simulations. Our results demonstrate that mapping the tDCS current-induced magnetic fields in individual subjects is feasible; opening an avenue to map electric currents directly and track target engagement in individual subjects. |
| 1947 | A stabilized convection-reaction magnetic resonance electrical property tomography (crMREPT) using viscosity-type regularization | |
1Singapore University of Technology and Design, Singapore, Singapore, 2Center for Frontier Medical Engineering, Chiba University, Japan, 3Department of Surgery, National University of Singapore, Singapore |
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Convection-reaction MREPT (crMREPT) method is a more general approach to reconstruct an electrical property map based on B1-maps from a magnetic resonance imaging (MRI) scanner compared to other existing methods in the literature, such as electrical property tomography (EPT) and local Maxwell tomography (LMT). However, crMREPT shows global spurious oscillations in the reconstructed maps and persistent artifacts in the region when $$$\small\triangledown|B_1|$$$ is small. We propose a solution to effectively mitigate the artifacts by applying a viscosity-type regularization. This abstract shows that the proposed method significantly increases the accuracy of the reconstructed electrical property maps and reduces the sensitivity to noise comparing to crMREPT. |
| 1948 | Three-Dimensional Model-Based Conductivity Mapping with Regularization and a Non-Negativity Constraint | |
1Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States |
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We present a three-dimensional model-based approach to calculating conductivity using MRI. Our proposed method is formulated as an inverse problem based on the phase-based conductivity equation. The algorithm includes an edge-preserving regularization term and we explore the utility of non-negativity constraints. Structural information is also used to inform regions over which to regularize. We present results for simulation, phantom, and human brain data. |
| 1949 | Use of Padding to Eliminate Low Convective Field Artifact in Conductivity Maps Obtained by cr-MREPT | |
1Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey |
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Convection-reaction equation based Magnetic Resonance Electrical Properties Tomography (cr-MREPT) has been developed by Hafalir et.al; however Low Convective Field causes artifacts. This study investigates how padding can be used in practice to eliminate the LCF artifact in conductivity reconstructions. Simulation and experimental results are given to demonstrate that conductivity images are improved by padding. |
| 1950 | In Vivo Current Density Distribution of Brain during Electrical Stimulation | |
1Kyung Hee University, Seoul, Korea, Republic of, 2Radiology, Chonnam National University Medical School, Gwangju, Korea, Republic of, 3Konkuk University, Seoul, Korea, Republic of |
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In deep brain stimulation, in vivo mapping of brain response is indispensable to secure its clinical applications. Estimation of current density distribution by stimulating currents can provide alternative way for understanding the therapeutic effects in electrical stimulation. MREIT method enables high-resolved mapping of electromagnetic tissue properties such as current density and conductivity of living tissues. In this study, we experimentally imaged current density distribution of in vivo canine brains by applying MREIT to electrical stimulation. The resulting current pathway and volume activation may provide useful information for adjusting the surgical planning and proving the therapeutic effects of DBS. |
| 1951 | Conductivity Measurements at 21.1 T using MR Electrical Property Tomography | |
1Center for Interdiscplinary Magnetic Resonance, Florida State University, Tallahassee, FL, United States, 2Physics, Florida State University, Tallahassee, FL, United States, 3Chemical & Biomedical Engineering, Florida State University, Tallahassee, FL, United States |
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This study explores the opportunity of using ultra-high field (21.1 T) for producing electrical conductivity maps. Phantoms with known NaCl concentrations were used to compare conductivity maps generated by phase-based MREPT with actual values measured at 900 MHz with a dielectric probe. Phase-based MREPT also was evaluated for in vivo ischemic brain using an MCAO rat model. Increased conductivity values were noted in the stroked region of the rat brain. |
| 1952 | Current density imaging using novel carbon electrodes proposed for Deep Brain Stimulation (DBS) | |
1School of Biological and Health Systems Engineering, Arizona State University, TEMPE, AZ, United States |
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Deep Brain Stimulation (DBS) is popular in the treatment of movement disorders. Conventional metal DBS electrodes present MR safety and susceptibility problems. We implemented novel carbon fiber electrodes that produced low susceptibility artifacts for imaging DBS current densities at 7 T. We used Magnetic Resonance Electrical Impedance Tomography (MREIT) to measure the z-component of the magnetic flux density (Bz) resulting from DBS-like pulses and reconstructed projected current density maps (JP) in two objects (agarose-gelatin phantom and ex-vivo piglet brain). We did not observe susceptibility artifact, and reconstructed projected current density maps agreed with simulation in the electrode neighborhood. |
| 1953 | Quantitative Susceptibility Mapping of Paramagnetic and Diamagnetic Substances at 3T-MR, 1.5T-MR and CT. | |
1Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan, 2Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan |
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We compared QSM value of paramagnetic and diamagnetic substances at 3T-MR, 1.5T-MR, and CT in this study. Phantoms with different concentration gadoterate meglumine (Gd) and calciumcarbonate (CaCO3) were created. QSM at 3T and 1.5T and CT imaging were performed for these phantoms. QSM of Gd phantom showed positive susceptibility and QSM of CaCO3 showed negative susceptibility. QSM demonstrated consistent results in paramagnetic and diamagnetic substances at 3T and 1.5T. QSM and CT values were correlated well. |
| 1954 | Susceptibility Mapping Reveals Inter-Hemispheric Differences in Venous Density in Patients with Brain Arteriovenous Malformations | |
1Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 2Brain Repair and Rehabilitation, Institute of Neurology, University College London, London, United Kingdom, 3Leonard Wolfson Experimental Neurology Centre, Institute of Neurology, University College London, London, United Kingdom |
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Brain arteriovenous malformations (AVMs) are vascular abnormalities characterised by arteriovenous shunting with the lack of a capillary bed. Recent studies have shown that it is possible to create diagrams of the cerebral vein network (venograms) from images of magnetic susceptibility ($$$\chi$$$). Here, we used $$$\chi$$$-based venograms to calculate the hemispheric percentage of venous voxels (venous density) in each hemisphere in AVM patients and healthy subjects. We found larger venous densities in the AVM-containing hemispheres than in the contralateral hemispheres, and more variable venous density in AVM patients than in healthy subjects. |
| 1955 | Evaluating The Accuracy of Susceptibility Maps Calculated from Single-Echo versus Multi-Echo Gradient-Echo Acquisitions | |
1Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 2Leonard Wolfson Experimental Neurology Centre, Institute of Neurology, University College London, London, United Kingdom |
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For Susceptibility Mapping (SM), Laplacian-based methods (LBMs) can be used on single- or multi-echo gradient echo phase data. Previous studies have shown the advantage of using multi-echo versus single-echo data for noise reduction in susceptibility-weighted images and simulated data. Here, using simulated and acquired images, we compared the performance of two SM pipelines that used multi- or single-echo phase data and LBMs. We showed that the pipeline that fits the multi-echo data over time first and then applies LBMs gives more accurate local fields and $$$\chi$$$ maps than the pipelines that apply LBMs to single-echo phase data. |
| 1956 | A Robust 3D Phase Unwrapping Method with Application to Quantitative Susceptibility Mapping | |
1School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu, People's Republic of China, 2Guangdong Provincial Key Laborary of Medical Image Processing, School of Biomedical Engineering, Southern Medical University, Guangzhou, People's Republic of China, 3Philips Healthcare, Guangzhou, People's Republic of China |
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In susceptibility-weighted imaging and quantitative susceptibility mapping, phase unwrapping methods are generally needed to restore the underlying true phase from the principal period (-π, π]. However, current phase unwrapping algorithms are challenged by noise, rapid phase changes and open-end cutlines. In this paper, a 2D phase unwrapping method based on pixel clustering and local surface fitting (CLOSE) was extended to 3D. The simulation and in vivo data is used to test the performance of the proposed method, with a comparison to a region growing method and PRELUDE, which are widely used for human brain phase-related imaging. The proposed method is demonstrated that can accurately unwrap 3D phase data even in the presence of severe noise, rapid phase changes, and open-end cutlines, and will benefit phase-related 3D MRI applications. |
| 1957 | Iterative Background Phase Correction: Recovering Data for QSM | |
1Institute of Neuroscience and Medicine - 4, Medical Imaging Physics, Forschungszentrum Jülich, Jülich, Germany, 2Department of Neurology, Faculty of Medicine, JARA, RWTH Aachen University, Aachen, Germany |
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We present a technique to improve the preparation process of phase data for QSM. In order to compensate for data loss caused by strong local phase gradients near the surface of the brain support, harmonic and dipole-based fitting are used to determine the responsible background fields within an extended brain mask. In an iterative approach, phase data are corrected regarding such contributions prior to further QSM processing steps. This allows for the acquisition of more reliable field maps and larger evaluation masks, which finally leads to more robust susceptibility maps. |
| 1958 | Incorporating macroscale susceptibility in QSM reconstruction with 3D spiral acquisition. | |
1Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 2Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 3Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 4Harvard Medical School, Boston, MA, United States, 5Boston Children’s Hospital, Boston, MA, United States |
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Macroscale magnetic susceptibility creates large variations in the phase images preventing the direct analysis of local tissue-dependent phase in quantitative susceptibility mapping. Unwrapping and background field removal are important steps for calculating tissue phases and susceptibility maps. In this work, a 3D spiral acquisition is combined with an image reconstruction pipeline modelling the macroscale magnetic susceptibility to provide more accurate tissue phases and susceptibility maps, by reducing image distortions and facilitating unwrapping and background phase removal. |
| 1959 | Effects of Spatial Resolution on Quantitative Susceptibility Mapping | |
1Radiology, University of Wisconsin, Madison, WI, United States, 2Medical Physics, University of Wisconsin, Madison, WI, United States, 3Biomedical Engineering, University of Wisconsin, Madison, WI, United States, 4Medicine, University of Wisconsin, Madison, United States, 5Emergency Medicine, University of Wisconsin, Madison, WI, United States |
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The purpose of this study was to investigate the effects of spatial resolution on the performance of quantitative susceptibility mapping (QSM). The combination of magnitude contrast in spoiled gradient echo images and the voxel sensitivity function can create significant errors in the estimated B0 field map. This work evaluated the use of proton density weighted imaging and joint R2* and field map estimation to reduce the impact of imaging resolution on QSM. Our results indicate that reducing magnitude contrast in the complex-valued echo images will reduce errors in the field map estimates and, thus, the susceptibility estimates in QSM. |
| 1960 | Evaluation of Quantitative Susceptibility Mapping for the visualization of the Globus Pallidus Internus and Subthalamic Nucleus at 3T and 7T | |
1State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, People's Republic of China, 2Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China, 3Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, IL, United States, 4Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, United States |
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The globus pallidus internus (GPi) and subthalamic nucleus (STN) (Figure 1) were the commonly used nuclei in deep brain stimulation (DBS) for the treatment of the Parkinson disease. In this study, we evaluated the QSM, T2* weighted and SWI methods for the visualization the GPi and STN on both 3T and 7T scanners. Our results showed the QSM at 7T displayed an excellent delineation of the GPi and STN, compared with T2* and SWI images. |
| 1961 | Primal-Dual Implementation for Quantitative Susceptibility Mapping (QSM) | |
1Weill Cornell Medical College, New York, NY, United States, 2Cornell University, Ithaca, NY, United States |
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We investigate the computational aspects of the prior term in the field-to-susceptibility inversion problem for QSM. Providing a spatially continuous formulation of the problem, we analyze 1) its Euler-Lagrange equation that appears degeneracy and 2) the Gauss-Newton conjugate gradient (GNCG) algorithm that employs numerical conditioning. We propose a primal-dual (PD) formulation that avoids such degeneracy and use the Chambolle-Pock algorithm to solve this alternative formulation; thus numerical conditioning is not required. The two methods were tested and validated on numerical/gadolinium phantoms and ex-vivo/in-vivo MRI data. The PD formulation with the Chambolle-Pock algorithm was faster and more accurate than GNCG. |
| 1962 | The challenge of phase offset correction for quantitative susceptibility mapping at ultra-high field | |
1Centre for Advanced Imaging, University of Queensland, Brisbane, Australia, 2High Field Magnetic Resonance Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, 3Siemens Healthcare Pty Ltd, Brisbane, Australia, 4Cardiff University, School of Psychology, Cardiff, United Kingdom |
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One challenge in quantitative susceptibility mapping (QSM) at ultra-high field (> 3 T) is the combination of phase data from phased array receive coils. We assessed the performance of COMPOSER (COMbining Phase data using a Short Echo-time Reference scan) with separate reference scans and with an intrinsic reference scan, as well as a reference-free single-channel method. Our results show that reference scans can bias QSM results at ultra-high field. We conclude that ultra-short echo-time reference scans reduce quantitation bias and remove the transmit field phase when using COMPOSER to combine phase data at ultra-high field. |
| 1963 | Accuracy of magnetic resonance based susceptibility measurements | |
1Precision Measurement Laboratory, NIST, Boulder, CO, United States, 2Department of Physics, University of Colorado Boulder, Boulder, CO, United States |
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We examined the accuracy of MR-based susceptibility quantification relative to conventional measurements in preparation of making a standard susceptibility phantom. SQUID magnetometry of tissue mimics provides absolute accuracy of approximately 100 ppb while MR-based techniques give relative accuracy of 10 ppb. |
| 1964 | Quantification of Dendronized Superparamagnetic Iron Oxide Nanoparticles in Rat Liver Using Quantitative Susceptibility Mapping | |
1InBrain Lab, Department of Physics, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of Sao Paulo, Ribeirão Preto, SP, Brazil, Brazil, 2Laboratoire des sciences de l’ingénieur, de l’informatique et de l’imagerie (ICube), UMR 7357, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg/CNRS, Illkirch, France, 3Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medicine, Cornell University, New York, United States |
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Quantitative Susceptibility Mapping was environment independent to quantify iron of SPIONs compared with R2*. |
| 1965 | Assessment of melanin content and its influence on susceptibility contrast in melanoma metastases | |
1Department of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Institute of Radiology, University Hospital Erlangen, Erlangen, Germany, 3Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 4Department of Neuropathology, Institute of Pathology, University of Heidelberg, Heidelberg, Germany, 5German Cancer Consortium (DKTK), CCU Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 6Department of Neuroradiology, University of Heidelberg, Heidelberg, Germany |
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Melanoma metastases can be classified as melanotic or amelanotic based on their T1-weighted magnetic resonance signal. However, the underlying contrast mechanisms have remained unclear and have been attributed to melanin and/or blood products. In this study, non-hemorrhagic cerebral melanoma metastases were investigated using quantitative susceptibility mapping. Susceptibility values for metastases with no, small or high melanin content were very similar (‑0.023±0.046 ppm / -0.006±0.02 ppm / -0.018±0.017 ppm). Non-hemorrhagic melanoma metastases show weakly diamagnetic susceptibility values and melanin is not a source of strong susceptibility. |
| 1966 | A Simple Phase Imaging REconstruction method (ASPIRE) | |
1High Field Magnetic Resonance Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria |
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Combining phase data from multi-channel coils at high field is challenging. Many approaches involve optimization or iterative steps which require offline reconstruction. We present a simple method that avoids the need for unwrapping or other fragile or time consuming steps by using echo times that satisfy $$$T_{E,2}=2\,\cdot\,T_{E,1}$$$. ASPIRE is compared with the Roemer method, MCPC-3D-I and the Hermitian inner product. ASPIRE achieves similar phase matching quality to Roemer but has the advantage that the combined phase values correspond to the B0 field. It is less computationally demanding than MCPC-3D-I and has higher CNR than the Hermitian inner product. |
| 1967 | Enhancing Quantitative Susceptibility Mapping by Using Gradient L2 Regularization with Morphological Priors | |
1Guangdong Provincial Key Laboratory of Medical Image Processing,School of Biomedical Engineering,Southern Medical University, Guangzhou, People's Republic of China, 2Philips Healthcare, Guangzhou, China. |
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TKD, LSQR and CSC methods have been proposed to reconstruct QSM from field map. However, these three methods result in inconsistent in the magic angle and can be further improved. This work introduces efficient gradient L2 regularization with morphological information from magnitude images for enhancing the QSM reconstructed by TKD, LSQR and CSC methods. |
| 1968 | Functional and structural ex vivo “MRI staining” using manganese-enhanced MRI (MEMRI), Gd-DTPA and Mn-Gd mixture | |
1Molecular Imaging and Theranostics, National Institute of Radiological Sciences, QST, Chiba, Japan, 2Department of Nutrition, Faculty of Medical and Health Sciences, Tsukuba International University, 3Anatomy and Neuroscience, The University of Melbourne, 4The Florey Institute of Neuroscience and Mental health |
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To reveal brain 3D microstructures noninvasively and microscopically using MRI, we developed “ex vivo MEMRI” and Mn-Gd double-contrast methods, and then compared them with conventional ex vivo Gd-DTPA-doped contrast. Because MEMRI sample loses contrast after perfusion fixation, we examined the stability of Mn2+ accumulation in ex vivo tissue samples. In addition, we tried to improve the contrast of MEMRI in combination with Gd-DTPA. The Mn-Gd double-contrast showed novel contrast and improved visibility. The functional “MRI staining” methods we developed in this study will be useful for visualizing whole brain 3D microstructures with a higher throughput compared to histological staining. |
| Exhibition Hall | Tuesday 16:15 - 18:15 |
| 1969 | A singular value decomposition approach to quantitative magnetization transfer | |
1NMR Unit, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2FMRIB Centre, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom |
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Quantitative magnetization transfer experiments require extensive sampling of the off-resonance spectrum to obtain information of the relaxation properties of non-water protons. To reduce the acquisition times, the off-resonance sampling has been optimized in previous works based on the stability of approximate biophysical model fits. Here, we use a singular value decomposition approach for the analysis of the principal components. In particular we propose a data-driven optimization method for the acquisition scheme and we discuss the potential impact of applying this analysis for parameter estimations, including potential extensions of the classical biophysical models. |
| 1970 | Highly Accelerated Chemical Exchange Saturation Transfer (CEST) Imaging by Combining Parallel Imaging and Compressed Sensing at 3T | |
1Bio-Imaging Research Team, Korea Basic Science Institute, Cheongju, Korea, Republic of, 2Bio-Analysis Science, University of Science and Technology, Daejeon, Korea, Republic of, 3University of Southern California, Los Angeles, CA, United States, 4Philips Healthcare Korea, Seoul, Korea, Republic of, 5Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 6Radiology and Radiological Sciences, Vanderbilt University, Nashville, United States, 7Opthamology, Vanderbilt University, Nashville, TN, United States |
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Chemical Exchange Saturation Transfer (CEST) imaging is an emerging molecular MRI method. It has been difficult for CEST imaging to adopt into clinical routine since CEST imaging is required relatively long scan time due to multiple saturation offsets. Here, we propose a novel, highly accelerated 3D CEST reconstruction technique by combining parallel imaging and compressed sensing. |
| 1971 | Fast, Reliable 3D Amide Proton Transfer Imaging of Brain Tumors at 3T with Variably-accelerated Sensitivity Encoding (vSENSE) | |
1Division of MR Research, Department of Radiology, 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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The clinical use of amide proton transfer (APT) imaging is hindered by long scan times. Accuracy generally limits the use of conventional sensitivity encoding (SENSE) methods in APT, to an acceleration factor of 2. A novel variably-accelerated sensitivity encoding (vSENSE) method can provide more accurate results and therefore substantially higher overall acceleration factors than conventional SENSE. Here, vSENSE is further developed to eliminate the requirement that one fully-sampled APT frame be acquired, and extended to three dimensions (3D). Furthermore, we combine vSENSE with parallel transmit saturation, and apply it proactively to three normal volunteers and eleven patients with brain tumors. |
| 1972 | isoAPTR* - a novel method to measure tumour pHi using CEST MRI | |
1Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom, 2Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford |
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Quantitative CEST MRI studies have so far been hindered by the fact that variations in multiple factors produce identical CEST effect changes. This remains the case when CEST MRI data are analysed using metrics that control for the contaminating effects of T1 and T2, such as APTR*. In this work we introduce isoAPTR*, a novel methodology which, in combination with independent measurement of labile proton concentration, can estimate the change in intracellular pH between two APTR* measurements. We demonstrate the utility of this method by applying it to measure the intracellular pH of U87 glioma in rats. |
| 1973 | The comparison of different strategies for transmit field inhomogeneity correction of Amide-CEST and NOE effects at 7T | |
1Department of Radology, University Medical Center Utrecht, Utrecht, Netherlands, 2Division of Medical Physics in Radiology, Deutsches Krebsforschungszentrum (DKFZ) [German Cancer Research Center], Heidelberg, Germany, 3Spinoza Center for Neuroimaging, Amsterdam, Netherlands, 4Scheffler, Max Planck Institute for Biological Cybernetics, Tübingen, Germany |
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We compared three methods for B1 correction of relaxation-compensated Amide-CEST and Nuclear Overhauser Enhancement (NOE) effects at 7T: (1) a linear model; (2) the eight-point interpolation method; and (3) Bloch-McConnell equations (BE) correction algorithm. In the low B1 regime of 0.10 - 0.50 µT, a simple linear model is sufficient to mitigate B1 inhomogeneity of Amide-CEST and NOE effects at 7T. |
| 1974 | Quantification of Multi-pool Contribution to Endogeneous CEST Effects in Global Ischemia | |
1Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, 2Department of Radiology, 3rd Affiliated Hospital, Zhengzhou University, Henan, People's Republic of China |
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CEST MRI has been used for quantitative assessment of dilute metabolites and/or pH in ischemic tissue and in tumors. However, conventional asymmetry analysis (MTRasym) may be confounded by concomitant effects such as RF spillover, semisolid macromolecular MT and NOE effects. Therefore, decoupling multiple contributions is essential for elucidating the origins of in vivo CEST contrast for improved quantification. Here we used an Image Downsampling Expedited Adaptive Least-squares (IDEAL) fitting algorithm which is not strongly constrained by image SNR and initial values for fitting. It provides a closer estimation of MTRasym that calculated from acquired data than voxel-wise multi-pool Lorentzian fitting and unravels the major contributors to CEST contrasts between white and gray matters as well as to the CEST changes after global ischemia. |
| 1975 | Lorentzian Probabilistic Sum based Z-Spectrum fitting approach for computing CEST and NOE contrast and its Comparison with Lorentzian Sum and Asymmetry Analysis | |
1Centre for Bio-Medical Engineering, Indian Institute of Technology Delhi (IIT Delhi), New Delhi, India, 2Department of Biomedical Engineering, All India Institute of Medical Sciences Delhi, India, New Delhi, India |
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In this study, we proposed a Z-spectrum fitting method based upon Lorentzian Probabilistic Sum (LPS) for computing CEST and NOE contrast. Proposed fitting method was tested on multi-pool Z-spectra data acquired using simulations and from in-vivo human brain data at 7T. Proposed fitting results were compared with asymmetry analysis and another fitting method based on Linear Sum (LS) of Lorentzian functions. Results of this study show that both LPS and LS nicely fit z-spectra; however, LPS provide more accurate estimation of NOE and CEST contrast. Therefore, proposed LPS model can be used for improved estimation of separate CEST and NOE components. |
| 1976 | 3D gagCEST of articular cartilage in the knee at 7 T correlates with clinical findings | |
1University Medical Center Utrecht, Utrecht, Netherlands, 2Orthopaedics, University Medical Center Utrecht, Utrecht, 3Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 4Faculty of Science and Technology, University of Twente, Enschede, Netherlands, 5MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, Netherlands |
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The purpose of this study was to assess the sensitivity of 3D gagCEST at 7T in cartilage repair patients with respect to healthy volunteers. Six healthy volunteers were scanned for stability assessments and five patients with cartilage defects were included to assess clinical applicability of the gagCEST sequence. The mean GAG effect size in healthy controls is 10.2 %, which is three times higher than the coefficient of variation in the stability assessments. The results of this study demonstrate the stability of 3D gagCEST at 7T and the results from patients with cartilage defects indicate a correlation with clinical findings. |
| 1977 | Quantitatively Evaluate the Chemical Exchange Effect in Off-resonance Spin Lock Using Perturbation of Longitudinal Relaxation Rate in Rotating Frame (PLRF) Analysis | |
1Center for MRI Research, Peking University, Beijing, People's Republic of China, 2MR Research Group, GE Healthcare China, Beijing, People's Republic of China |
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Chemical exchange effect can be evaluated by off-resonance spin-lock sequence (CESL), but it remains unclear whether the effect is accurately reflected. In this study, with the help of perturbation of longitudinal relaxation rate in rotating frame (PLRF) analysis, we quantitatively compared signal from CESL and chemical exchange saturation transfer (CEST) sequences and tested the condition for acquiring high-quality signal from CESL sequence which can accurately reflect chemical exchange effect. |
| 1978 | Chemical exchange rotation transfer (CERT) using adiabatic hyperbolic secant pulses | |
1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States |
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Chemical exchange rotation transfer (CERT) is an emerging approach for imaging solutes and solute exchange that avoids some of the contributions from the asymmetric background in biological tissues that confound chemical exchange saturation transfer (CEST). To further improve the robustness of CERT methods when there is field inhomogeneity, we examined adiabatic hyperbolic secant pulses for solute saturation. In addition to addressing field homogeneity issues, this new method reveals a new mechanism to generate contrast based on the delay time between pulse. |
| 1979 | Elegant method to quantify chemical exchange processes for pH CEST imaging | |
1Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Department of High-field Magnetic Resonance, Max-Planck-Institute for Biological Cybernetics, Tübingen, Germany |
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A novel concentration-independent approach is presented to determine the pH-dependence of exchange rates employing a single CEST image of a set of model solutions at different pH. Not only the comparatively short acquisition time, but also the robustness against variations in relaxation parameters makes this modality an elegant way to determine exchange rates in vitro. The calibrated functions are required for accurate pH mapping in vivo using CEST, as well as for design of exogenous CEST contrast agents. |
| 1980 | Muscular glycogen detection with CEST imaging in living rat at 14.1T | |
1Laboratory for functional and metabolic imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2Center for Biomedical Imaging (CIBM-AIT), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland |
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Glycogen is the principle intracellular storage for energetic needs in muscle and information about its spatial distribution would be a great additional tool for traumatology and sport sciences. In this study, we aimed to map in vivo muscular glycogen using CEST imaging in rodent. We have shown that optimal B1 saturation power allowed CEST imaging glycogen distinguishable from the neighboring creatine at 14.1 Tesla. We applied our optimized protocol on muscle after exercise session, resulting in 50% reduction of MTRasym comparing to muscle at resting state. This is supporting the specificity of our method and is consistent with literature. |
| 1981 | Rapid 3D CEST using volumetric reduced field of view imaging | |
1Wuhan Children Hospital, Wuhan, People's Republic of China, 2GE healthcare MR Research China, Beijing, People's Republic of China, 3GE healthcare MR Research China |
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A reduced field of view CUBE acquisition was proposed for CEST imaging. It is advantageous in situations where the imaging volume may be constrained to a region of the whole volume. Clinical feasible acquisition (10s per volume) was achieved at 2mm isotropic resolution. |
| 1982 | The origins of CEST contrast in ischemic tissue: effects of hypotonic stress on the nervous system of Aplysia californica | |
1NeuroSpin, Commisariat à l'Energie Atomique et aux Energies Alternatives, Gif-sur-Yvette, France |
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Recent CEST MRI methods such as Amide Proton Transfer (APT) imaging allow the detection of brain tumors and stroke by generating novel image contrasts which depend on the chemical exchange. In this paper, we are studying the effects of ischemia on the CEST signal at a tissue level using the nervous system of Aplysia californica, a widespread model in neuroscience. A significant change in the Z spectrum was observed at 2.5 ppm after hypotonic shock in the abdominal ganglion and was quantified as a +2.88% MTR increase. Cell swelling, which is a known phenomenon in ischemic tissue, could potentially cause such effect. |
| 1983 | Simultaneous Acquisition of Multiple Z-spectra using Sinc-Modulated RF Pulse Trains in Gradient Encoded CEST MRI | |
1Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Kyoto, Japan, 2Department of Systems Science, Graduate School of Informatics, Kyoto University, Kyoto, Japan |
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We propose a use of sinc-modulated RF pulse train instead of the conventional continuous wave RF irradiation under the presence of constant gradient as a saturation scheme in chemical exchange saturation transfer (CEST) MRI aiming at a simultaneous acquisition of multiple Z-spectra. The proposed method was applied for a glutamic acid solution in water. The multiple Z-spectra could be observed along the gradient encoding direction by repetitive application of the saturation scheme. Thus, the present study shows the potential of the proposed methodology for accelerating the CEST MRI. |
| 1984 | Investigation of magnitude and phase CEST effects in fixed whole brains and tissue samples: a combined 3T and 9.4T study | |
1Research Centre Juelich, Juelich, Germany |
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Saturation transfer effects were investigated in fixed tissue at 3T and 9.4T and a range of saturation powers. Z-spectra on magnitude as well as phase data were studied with high spatial and spectral resolution, also due to the excellent performance of a PCA-based denoising algorithm. The preliminary findings do not support the presence of an APT effect in fixed tissue; however, saturation transfer effects could be enhanced in pathological tissue, similar to in vivo findings in e.g. tumour or stroke. This study opens the way to a systematic investigation of saturation transfer effects in healthy and pathological fixed tissue. |
| 1985 | An assessment of interdependent chemical exchange saturation transfer (CEST) signals from metabolites with overlapping chemical shift frequencies and proton exchange rates | |
1Advanced Imaging Researh Center, UT Southwestern Medical Center, Dallas, TX, United States |
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The objectives are to investigate how the chemical exchange saturation transfer (CEST) signal measured at a given frequency is independent of the neighboring CEST signals. We measured the CEST signals from combinations of four metabolites at 3.5, 3, 2 and 1 ppm with 5 different powers and 3 different durations of presaturation pulse to investigate the parameter-dependence and interdependency of each CEST signal in phantoms. The CEST signal of glutamate was less impacted by concentration changes in other exchanging species by subtracting CEST signals at two different power levels. |
| 1986 | Modeling the increased inhomogeneous magnetization transfer (ihMT) signal from high amplitude, low duty cycle irradiation | |
1Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, 2Aix Marseille Univ, CNRS, CRMBM, Marseille, France |
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Pulsed implementations of RF saturation for MT and ihMT are dependent on the duty cycle of the MT pulse relative to its repetition period. The ihMT signal increases following preparation with high B1, low duty cycle MT pulses. A model was developed to fit ihMT data acquired at different duty cycles, along with the more standard variations in power and offset frequency. Output parameters from the fit were reasonable. The model allowed simulation of the ihMT signal as a function of experimental parameters related to the saturation preparation, and can be used to guide future experiments and/or optimize ihMT. |
| 1987 | Improved Measurement Precision for AACID CEST MRI of Brain pH using the 2 ppm Amine Resonance | |
1Department of Medical Biophysics, University of Western Ontario, London, ON, Canada, 2The Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, ON, Canada |
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The chemical exchange saturation transfer (CEST) method called Amine and Amide |
| 1988 | Towards Eliminating Magnetization Transfer (MT) Effect on CEST Quantification Using MR Fingerprinting: Simulations | |
1Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China, 2Key Laboratory of Particle and Radiation Imaging, Ministry of Education, Beijing, People's Republic of China, 3Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 4Department of Bioengineering, University of California Los Angeles, Los Angeles, CA, United States, 5Department of Imaging, Cedars-Sinai Medical Center, Los Angeles, CA, United States |
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In this work, a new quantitative chemical exchange saturation transfer (q-CEST) method based on MR fingerprinting is developed to eliminate the influence of MT effect. Signal evolutions are generated by using a series of hard saturation pulses with different amplitudes and durations. The dictionary is constructed using the 2-pool model. Simulation experiments based on the 3-pool model were performed, and simulation results show that good mapping accuracy was achieved even in the presence of the MT effect. |
| 1989
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Towards an Early Detection of Prostate Cancer using Zinc-Sensitive iCEST MRI | |
1The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, MD, United States |
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As compared to normal prostate tissue, prostate cancer cells exhibit a dramatic reduction in zinc content. We have used 19F-based ion-CEST (iCEST) MRI to sense differential Zn2+ levels between normal and malignant prostate cell lines. We were able to observe clear differences in zinc-induced iCEST signal between normal cells and cancer cells, which was validated by microscopy using a zinc-sensitive fluorescent dye. Hence, iCEST MRI may have potential as a new means to non-invasively detect early prostate malignant transformation. |
| Exhibition Hall | Wednesday 8:15 - 10:15 |
| 1990 | A biodegradable macromolecular MRI contrast agent for enhanced liver metastasis | |
1Radiology, Sir Run Run Shaw Hospital, Zhejiang, People's Republic of China, 2Chemical and Biological Engineering, Zhejiang University, Zhejiang, People's Republic of China, 3Life Science, GE healthcare, Shanghai, People's Republic of China |
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Tumor metastasis accounts for the related mortality, and precise diagnostic imaging of distant metastasis plays a significant role in clinical administration and treatment plan. Enhanced MRI with small-molecule contrast agent (CA) is a favorite imaging modality. However, small-molecule CA has some unsatisfied flaws such as short blood circulation time, low relaxivity and non-specificity. In this study, we synthesized a macromolecular CA with high relaxivity and long blood circulation time, and assessed early liver metastasis with enhanced MRI using this macromolecular CA. |
| 1991 | 3D contrast enhanced high definition, free-breathing Dixon imaging using radial stack of stars and respiratory gating and tracking: Clinical comparison to state of the art breath hold Dixon imaging | |
1Philips Healthcare, Best, Netherlands, 2Philips Healthcare, Switzerland, 3Institute for Radiology and Nuclearmedicine, Kantonsspital Winterthur, Switzerland |
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We investigated a motion immune Dixon TFE approach incorporating a 3D radial stack-of-stars acquisition module interleaved with a spiral excitation navigator to gate and track the acquisition. Image quality, sharpness and streaking artifact level and its variability over different patient breathing patterns is efficiently improved to an extent where it is preferred over the state-of-the art breath hold (BH) Dixon scans. Next to that, it allowed scan time reductions of 30% in average. This technique provides motion-free, high resolution hepatic imaging with the benefits of Dixon providing consistent good fat suppression over a large FOV with water, fat, IP and OP diagnostic information all-in-one scan. |
| 1992 | Quantification of Hepatic Fat Fraction and Liver/Spleen R2* in a Healthy Cohort at 3 Tesla | |
1School of Medicine, Dalhousie University, Halifax, NS, Canada, 2Biomedical Translational Imaging Centre, QEII Health Sciences Centre, Halifax, NS, Canada, 3Department of Diagnostic Radiology, Dalhousie University, Halifax, NS, Canada |
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Non-invasive quantification of hepatic fat and iron with MRI has generated increasing clinical interest, particularly given the prevalence of chronic liver disease. Elevated R2* is a biomarker of iron deposition in the liver and spleen. The normative distribution of R2* in these organs at 3T is not well described, but is necessary for confident diagnosis of mild to moderate levels of iron deposition. Based on measurements in 97 adults selected from the general population, we confirm that ~20% have fatty liver and suggest that a hepatic R2* > 89 s-1 and splenic R2* > 69 s-1 can be considered abnormal. |
| 1993 | Spectroscopy-Based R2 Relaxometry for Liver Iron Quantification at 1.5T and 3.0T | |
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 3School of Automation Engineering, University of Electronic Science and Technology of China, Chengdu, People's Republic of China, 4School of Biomedical Engineering and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, People's Republic of China, 5Medicine, University of Wisconsin School of Medicine and Public Health, WI, United States, 6Radiology, University of Texas-Southwestern, Dallas, TX, United States, 7Advanced Imaging Research Center, University of Texas-Southwestern, Dallas, TX, United States, 8Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 9Medicine, University of Wisconsin-Madison, Madison, WI, United States, 10Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States |
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R2-based techniques for liver iron quantification using Spin-Echo (SE) imaging require long acquisitions. In contrast, single-voxel Stimulated-Echo Acquisition Mode (STEAM)-MR spectroscopy enables liver R2 measurements in a single breath-hold. However, the accuracy and field strength dependence of STEAM-MRS R2 quantification are unknown. This study evaluated the accuracy and field strength dependence of STEAM-MRS for R2 quantification in healthy controls and patients with liver iron overload. At 1.5T, STEAM-MRS R2 was in close agreement with SE-MRI-based R2. Further, STEAM-MRS R2 measurements were highly correlated across field strengths. Finally, STEAM-MRS R2 measurements at 1.5T and 3.0T were calibrated to liver iron concentration. |
| 1994 | Correlation between incidental fat deposition in the liver and pancreas in asymptomatic patients | |
1The Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Hospital, Baltimore, MD, United States, 2The Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Hospital, 3Siemens Healthcare, Baltimore, MD, USA |
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Liver steatosis is the most common parenchymal liver disease in Western Countries and it may progress to steatohepatis, fibrosis and cirrhosis. Also, fat deposition in liver and pancreas can cause diabetes by increasing resistance to insulin. Magnetic Resonance Spectroscopy (MRS) has been shown to strongly correlate with histology in liver fat quantification. However, MRS has some limitations such as breathing artifact and difficulties in avoiding vessels or bile ducts within the voxel. So, it is desirable to utilize a novel and robust imaging technique that can screen for the presence of fat in the liver and pancreas. |
| 1995 | Hemodynamic Assessments of Hepatic Vasculatures using 4D-PCA and MRFD | |
1Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan, 2Center of Radiology and Radiation Oncology, Kobe University Hospital, Kobe, Japan, 3Radiology, Kobe University Graduate School of Medicine, Kobe, Japan |
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We introduced new assessment method of liver hemodynamics using 4D-PCA and new flow analytic technique including wall shear stresses. We found 4D-PCA and MRFD enables detailed hemodynamic assessment and has the potential to be used for liver disease assessments. |
| 1996 | MRI of Liver Cysts in Autosomal Dominant Polycystic Kidney Disease: Effect of Genotype | |
1Radiology, Weill Cornell Medicine, New York, NY, United States, 2Nephrology, Weill Cornell Medicine, New York, NY, United States, 3Radiology, Columbia University, New York, NY, United States |
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ADPKD patients (n=25) undergoing abdominal MRI were analyzed 2 times each by 2 separate reviewers using a) thresholding; b) region growing c) cyst diameter d) semi-manual segmentation to determine liver cyst volume. Using the most reproducible technique, 75 additional ADPKD patients were studied correlating their liver parameters with genotype, gender and age. Semi-manual segmentation was the best technique for measuring cyst volume with intraclass correlation coefficient of 0.99. PKD1 mutation was found to be associated with higher total liver volume and liver cyst volume across different age groups and gender compared to PKD2 mutation, suggesting greater hepatic involvement with PKD1. |
| 1997 | Feasibility and grading performance of Quantitative Susceptibility Mapping for Hepatic Iron quantification | |
1Department of Radiology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China, 2Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, United States, 3MR Collaboration NE Asia, Siemens Healthcare, Shanghai, People's Republic of China, 4Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, People's Republic of China, 5MR Applications Predevelopment, Siemens Healthcare, Erlangen, Germany, 6The Helen Wills Neuroscience Institute, University of California, Berkeley, CA, United States |
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This study aimed to evaluate the performance of Quantitative Susceptibility Mapping (QSM) on estimating and grading the liver iron concentration (LIC), using Ferriscan-R2 values as reference. Thirty-three patients suspected of hepatic iron overload were included in this study. The results showed a significant positive correlation between QSM and Ferriscan-based LIC (r=0.924). ROC analysis revealed that QSM could accurately grade LIC for low and moderate iron overload patients, indicating that high-quality QSM maps may allow to reliably estimate and grade iron deposition in the liver. |
| 1998 | Characterization of Primary Liver Cancers with DWI Histogram Analysis | |
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, 3Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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ADC measurement using DWI have shown promise for characterizing focal liver lesions. In this study, we assessed the ability of advanced ADC histogram parameters to distinguish the histological diagnosis and the grade of primary malignant liver cancers. We found that both ADC mean and ADC percentiles could distinguish between tumor types; ADC percentiles were also predictive of tumor grade for HCC and ICC. Advanced ADC histogram analysis may be useful for accurate tumor diagnosis and prediction of tumor grade. |
| 1999 | Simultaneous liver and spleen 2D MRE and 3D MRE acquisitions: Preliminary results | |
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Department of Radiology, Mayo Clinic, Rochester, MN, United States, 3Department of Biomedical Engineering, University of Delaware, DE, United States, 4Siemens Healthcare, Salt Lake City, UT, United States, 5Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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We present initial results of 2D MR elastography (MRE) and 3D MRE acquired in liver and spleen using a dual driver configuration in 13 subjects, 5 healthy and 8 with liver disease. 2D MRE showed a trend to higher stiffness in healthy subjects however in cirrhotic subjects liver stiffness was generally higher with 3D MRE. 3D MRE showed significantly higher liver stiffness in cirrhotic subjects compared to healthy subjects, with spleen stiffness also increased but not reaching significance. Coefficient of variation with single and dual drivers was 5% for liver and spleen in 2D and 3D MRE. |
| 2000 | Liver quantification with dynamic contrast-enhanced MRI for evaluation in hepatic function and staging of post-hepatitic liver cirrhosis | |
1MRI, The 1st affiliated hospital of Henan University of TCM, ZhengZhou, People's Republic of China |
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To evaluate the value of DCE-MR for hepatic reserve function assessment and staging in post-hepatitic liver cirrhosis (PHLC). 10 patients with compensatory PHLC, 10 with decompensatory PHLC and 10 healthy volunteers were performed DCE-MRI scanning. All data were calculated by Extended Tofts model fitting with pharmacokinetic curve and the permeability and perfusion parameters were measured in quantification. The new method validated the feasibility of using quantitative parameters of DCE-MRI with pharmacokinetic model to assess liver cirrhosis. In conclusion, DCE-MRI quantitative parameters can be used for diagnosing and staging liver cirrhosis. |
| 2001 | Assessment of the Hepatocyte Fraction for Estimation of Liver Function Based on a Simple Pharmacokinetic Model | |
1Radiology, Ruijin hospital of Shanghai Jiaotong University, Shanghai, People's Republic of China, 2Ruijin hospital of Shanghai Jiaotong University, 3Jinshan hospital of Fudan Univeristy |
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There were 16 consecutive patients (12 men, 5 women; mean age, 45.7 years; range, 33–65 years). Imaging was performed on clinical 3T scanner (Philips Ingenia) using 32ch body/cardiac coil. A hepatocyte fraction (HF) map and K map were derived. The HF and K values for Gd-EOB-DTPA were correlated with Child-Pugh scores. Patients with Child-Pugh class B disease showed significantly lower liver FA value and K value. HF value and K value were positively correlated with the Child–Pugh scores (r=0.752 to 0.855, p<0.05). HF value and K value had the largest AUC of 0.975 and 0.78 for distinguishing the Child–Pugh class A of cirrhosis from class B. K value had the most area under receiver operating characteristic curve (AUC) of 0.99 for identifying the presence of liver cirrhosis.The study suggested that hepatocyte fraction and hepatic uptake derived from Gd-EOB-DTPA-enhanced MRI can quantify liver function. |
| 2002 | Quantitative T1 and T2 measurements of pancreas at 7 Tesla using a multi-transmit system | |
1Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Imaging Division, University Medical Center Utrecht, Utrecht, Netherlands, 3Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
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Inversion recovery and echo time series were obtained at 7T with a multi-transmit system to determine the T1 and T2 relaxation times of the healthy pancreas. These parameters are crucial when optimizing MR protocols. The T1 and T2 values found were in average 921+/-98 ms and 57+/-12 ms respectively. Excellent T2 contrast is obtained for the pancreas at TE/TR=80ms/17s. |
| 2003 | Quantitative Assessment of Hepatic function with Hepatocyte Fraction | |
1Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China, 2Guangdong Provincial Key Laboratory of Medical Image Processing,School of Biomedical Engineering,Southern Medical University, Guangzhou, People's Republic of China, 3Philips Healthcare, Guangzhou, China., 4MR Clinical Science, Philips Healthtech, Tokyo, Japan, 5MR Clinical Science, Philips Healthcare, Seoul, Korea |
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Gadoxetic acid has been shown to evaluate liver function as it is known to be actively taken up by hepatocytes via organic anion transporters (OATPs). The measurement of hepatic parenchymal enhancement during the hepatobiliary phase (HBP) may accurately reflect liver function. This study evaluated the liver function of the subject in the Child-Pugh classification method which is still the most commonly applied method for evaluating liver function in clinical. The hepatocyte fractions were significantly different among groups classified according to Child–Pugh scores between A and C, B and C. The hepatocyte fraction could be considered as a promising method for the quantitative assessment of liver function. |
| 2004 | Assessment of interrater agreement and reliability for characterization of respiratory motion related artifacts at gadoxetate disodium-enhanced liver MRI | |
1Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany, 2Department of Diagnostic and Interventional Radiology, University Hospital of Bonn, Bonn, Germany, 3Department of Medical Biometry, Informatics and Epidemiology, University Hospital of Bonn, Bonn, Germany, 4Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt, 5Department of Diagnostic and Interventional Radiology, Klinikum der Stadt Ludwigshafen, Ludwigshafen, Germany, 6Department of Radiology, University Hospital of Bern, Bern, Switzerland, 7Division of Radiology and Nuclear Medicine, Kantonspital St. Gallen, St. Gallen, Switzerland, 8Department of Radiology, Asklepios Klinik Altona, Hamburg, Germany, 9Instiute of Diagostic and Interventional Radiology, Städtisches Klinukum Karlsruhe, Karlsruhe, Germany, 10Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen, Germany, 11Department of Radiology, University Hospital Regensburg, Regensburg, Germany, 12Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany, 13Department of Radiology, Neuroradiology, Ultrasounnd and Nuclear Medicine, Krankenhaus der Barmherzigen Brueder, Trier, Germany |
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In this prospective multicenter study, interrater agreement and reliability for characterization and grading of respiratory motion artifacts related to the injection of gadoxetate disodium were evaluated. Interrater agreement and reliability for scoring of motion artifacts in the arterial phase was excellent among experienced abdominal radiologists from different European tertiary referral centers with an intraclass correlation coefficient of 0.983 and 0.985, respectively. Characterization and grading of respiratory motion artifacts can thus be performed with a high level of confidence, which is a prerequisite for assessing the incidence of this phenomenon in larger multicenter studies. |
| 2005 | The predictive value of diffusion-weighted imaging on radiation-induced liver injury of hepatic malignancies | |
1Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, People's Republic of China |
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Radiation-induced liver injury (RILI) is one of the most dreaded complications of radiation therapy (RT)，which prevents radiation dose escalation and limits the effectiveness of the treatment . Therefore, it was important to predict and evaluate the RILI on hepatic malignancy using the RT in the early term. In this study, the ADCmid-RT value was significantly highest, and had negative correlation with the radiation dose. As the ADCmid-RT value was less than 1.29 x10-3mm2/s, the RILI could possibly occur. Therefore, the ADCmid-RT value may serve as a biomarker for predicting RILI in patients with hepatic malignancies treated with RT. |
| 2006 | Inter- and intra-reviewer agreement of region-of-interest-based quantification of liver R2* in patients with 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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This study evaluated the inter- and intra-reviewer agreement of different region-of-interest (ROI) sampling methods for the quantification of liver R2* (1/T2*) in patients with iron overload. 37 MRI datasets from patients suspected of having liver iron overload were retrospectively analyzed using ROI sampling methods that have been previously reported. Our results demonstrate that the inter- and intra-reviewer agreement of liver R2* quantification improve when using ROIs that are large in size and number. We conclude that researchers and clinicians should strive to sample as much area of the liver by using multiple large ROIs. |
| 2007 | Hepatocellular Carcinoma with Capsule Appearance in Gadoxetic Acid-enhanced MR Images : Correlation with Dynamic CT and Pathologic Fibrous Capsule | |
1Radiology, Ajou University School of Medicine, Suwon, Korea, Republic of, 2Pathology, Ajou University School of Medicine, Suwon, Korea, Republic of |
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For visualization of capsule appearance on HCC, GaMR is comparable with dynamic CT. And pathologic fibrous capsule can be seen as hypointense rim in HBP. Lower visualization of capsule appearance in TP on GaMR seem to be parenchymal enhancement during the transitional phases. Hyperintensity rim in T2 weighted images with hopointense rim on HBP shows disruption of fibrous capsule with extension of tumor cells across the fibrous capsule in pathology. Hypointense rim on the HBP in the 2014 version of LI-RADS should not be considered as capsule appearance, and further study is also needed. |
| 2008 | Liver T1rho Distribution across Eight Functionally Independent Segments | |
1Philips Healthcare, Shanghai, People's Republic of China, 2Shandong Medical Imaging Research Institute Affiliated to Shandong University, Shandong University, Ji Nan, People's Republic of China, 3Department of Radiology, Shanghai Institute of Medical Imaging, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China, 4Philips Healthcare, Hong Kong, People's Republic of China |
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ROI-based analysis may suffer from sampling errors due to the user-defined placement of the ROI and the choice of slice location. The aim of our study was to find an approach that allow the detection and measurement of the T1rho values of the hepatic segments. |
| 2009 | GRASP with Motion Compensation for DCE-MRI of the Abdomen | |
1Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard 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 method to combine information of respiratory states with a non-rigid motion model is proposed to reconstruct motion-compensated 4D images of dynamic-contrast enhanced MRI with high temporal resolution. Abdominal DCE-GRASP MRI was reconstructed by grouping 4 consecutive spokes as one dynamic frame (0.6sec/frame). Respiratory motion was obtained from central k-space data (as in XD-GRASP). A temporal TV constraint was applied separately for each respiratory state. By using an optical-flow algorithm, four sets of motion vectors were obtained. Motion-compensated GRASP reconstruction was performed by including the motion vectors and showed improved image quality and reduced motion blurring. |
| 2010 | HCC detection in pre-transplant patients: A comparative retrospective study between multiphasic CT, gadoxetic acid-enhanced MRI and extracellular gadolinium based contrast-enhanced MRI | |
1Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 3Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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In this study, we present preliminary data comparing the diagnostic performance of multiphasic contrast-enhanced CT with contrast enhanced MRI using a liver specific gadolinium based contrast agent (GBCA), gadoxetic acid (Gd-EOB-DTPA) and extracellular (EC) GBCAs, using explant pathologic data as the reference. We also assessed the added value of delayed hepatobiliary phase (HBP) imaging and DWI in HCC detection. Our data suggests that CT and MRI have similar overall sensitivities for HCC detection and that the addition of DWI and HBP improved HCC detection when using Gd-EOB-DTPA. |
| 2011 | The value of magnetic resonance elastography in differential diagnosis of hepatocellular carcinoma and intrahepatic cholangiocarcinoma | |
1Imaging Diagnosis, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College, beijing, People's Republic of China, 2National Cancer Center/Cancer Hospital, Chinese Academy of Medical Science and Peking Union Medical College |
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To determine the value of MRE in the differential diagnosis of hepatocellular carcinoma and intrahepatic cholangiocarcinoma with 3.0-T MR scanner . The MRE were performed in 36 patients(26 hepatocellular carcinomas and 11 intrahepatic cholangiocarcinomas) by using 60-Hz mechanical waves and Spin echo echo planar sequence.Intrahepatic cholangiocarcinomas had significantly greater mean shear stiffness than hepatocellular carcinoma (9.08 ±2.13kPa vs 6.54 ±1.84kPa). They have statistically significant differences(p<0.01).MRE can help the differentiation of hepatocellular carcinoma and intrahepatic cholangiocarcinoma. |
| 2012 | Hepatic fat quantification using automated six-point Dixon methods: comparison with conventional chemical shift based gradient-echo sequences and computed tomography. | |
1Diagnostic Radiology, Kumamoto University, Kumamoto, Japan |
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To compare automated six-point-Dixon(6-p-Dixon) with dual-echo GRE chemical shift imaging(CSI) for quantification of hepatic fat fraction(FF) with CT. In a phantom study, various FF vials were performed to validate the accuracy. In clinical study, fifty-nine patients were examined both 3.0T MRI and CT. Quantitative measurements were calculated SI-index of CSI and imaging-FF of 3D-6-p-Dixon. In phantom study, linear regression between FF and imaging-FF/SI-index showed good agreement(imaging-FF R2=0.992:0-100%FF;SI-index R2=0.978:0-34.7%FF). In clinical study, linear regression between imaging-FF and SI-index showed good agreement(R2=0.890). CT attenuation value was strongly correlated with imaging-FF(R2=0.852) and SI-index(R2=0.812). Imaging-FF of 6-p-Dixon has potential for automated hepatic fat quantification. |
| 2013 | Value of Noncontrast MR Imaging with Diffusion-weighted Imaging for Detection of Primary Small (≤ 20mm) Solid Pancreatic Tumors and Prediction of Pancreas Ductal Adenocarcinoma | |
1Radiology, Chung-Ang Universitiy Hospital, Seoul, Korea, Republic of, 2Samsung medical center |
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With recent advances of MRI in abdominal imaging, improved performances on T2-weighted image and diffusion- weighted imaging (DWI) are achieved for pancreatic tumors. We hypothesized that diagnostic performance for detection of primary solid tumors of pancreas on noncontrast MRI with DWI could be sufficiently high and noncontrast MRI with DWI would be useful for pancreas screening. We conducted this study to determine the diagnostic performance of noncontrast MRI with DWI for detection of primary small (≤20mm) pancreatic solid tumors and prediction of ductal adenocarcinoma in comparison with pancreas CT and pancreas MRI with MR cholangiopancreatography. |
| 2014 | Gadoxetic acid disodium-enhanced magnetic resonance imaging for staging of liver fibrosis: a meta-analysis | |
1The First Hospital of Medical School, Xi’an Jiaotong University, Xi'an, People's Republic of China, 2The First Hospital of Medical School, Xi’an Jiaoto, Xi'an, People's Republic of China |
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To collect and summarize parameters used by gadoxetic acid-enhanced MR imaging (GD-EOB-DTPA-enhanced MRI) for staging of liver fibrosis (LF) and evaluate diagnostic performance. A systematic literature search was performed in PubMed, Web of science, Embase and Medline database. Studies used frequently-used parameter were included. Pooled weighted mean difference (WMD) was applied to determine the clinical significance. Pooled sensitivity, specificity, and summary receiver operating characteristics (SROC) curve were calculated to evaluate diagnostic performance. Finally, 5 studies were included, and contrast enhancement index (CEI) was the most frequently-used parameter, which was considered to be an efficient biomarker in the staging of LF. |
| 2015 | Apparent Diffusion Coefficient of Hepatocellular Carcinomas on Diffusion-Weighted Imaging: Correlation with Histopathologic Tumor Grade versus Arterial Vascularity during the Dynamic MRI | |
1Department of Radiology, Yonsei University Gangnam Severance Hospital, Seoul, Korea, Republic of |
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Depending on the difference of cellular densities related to the histopathologic grades of HCCs, some investigators have recently suggested apparent diffusion coefficient (ADC) on diffusion-weighted imaging (DWI) as an effective biomarker for the prediction of the patients’ prognosis before the treatment of HCC. In the present study, ADCs of well- or poorly differentiated HCCs were lower than moderately differentiated HCCs; meanwhile the degree of arterial phase enhancement during the dynamic imaging rather well stratified the ADCs of the lesions. We concluded that ADC could not be independently used to estimate the histopathologic grades of HCCs. |
| 2016 | Quantification of liver fat after Gd-EOB-DTPA injection: a IDEAL-IQ feasibility study | |
1Department of MR, The First Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China, 2GE HealthCare, MR Research China, Beijing, People's Republic of China |
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This article is to explore the feasibility of liver fat quantification via dynamic liver enhancement scanning after injection of Gd-EOB-DTPA. IDEAL-IQ was used to quantify liver fat in 65 patients who were injected with contrast. IDEAL-IQ was performed four times to determine the fat fraction (FF) and R2*. One-way repeated-measures analysis was conducted to evaluate the difference between the four time points of the FF. The assessment of FF at four time points in liver, spleen and spine showed no significant differences. However, after injection of contrast agent, R2* was increased, and the IDEAL-IQ result was relatively stable. |
| 2017 | A Preliminary Study of the Clinical Value of FM Model in Malignant Tumor of Liver | |
1Department of Radiology, Beijing Chaoyang Hospital, Beijing, People's Republic of China |
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Several models have been proposed to explain the anomalous diffusion in biological tissues. Among them, the fractional motion (FM) model was considered more appropriate. In this study, the FM model was applied to assess its feasibility for diagnosing malignant tumors of liver. It was found that the FM model could improve the diagnostic accuracy in differentiation normal liver tissue and tumor lesion, indicating the potential of the FM model to facilitate future studies of pathological changes in clinical populations. |
| 2018 | Liver Iron Concentration determined with Gradient Echo MRI by Signal Intensity Ratio: Effects of Patient Characteristics | |
1Diagnostic and Interventional Radiology, Ulm University, Medical Center, Ulm, Germany, 2Section for Experimental Radiology, Ulm University, Medical Center, Ulm, Germany, 3Department of Pediatrics and Adolescent Medicine, Ulm University, Medical Center, Ulm, Germany |
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To investigate the relation between signal intensity ratios gained from gradient echo (GRE) MRI and liver iron concentration (LIC), we studied the influence of patient characteristics. 168 patients (71 f, 97 m; 49 with Thalassemia major, 101 without Thalassemia) suspected for liver iron overload were scanned according to Ferriscan® with spin echo MRI to obtain reference LIC values, and GRE protocols suitable for LIC determination. GRE analysis by manually drawn liver and muscle ROIs yielded liver-to-muscle signal intensity ratios (SIR). Correlation analysis of ln (SIR) to reference LIC revealed differences between patient subgroups concerning disease, gender and age. |
| 2019 | Liver Iron Concentration determined by Gradient Echo MRI using Signal Intensity Ratios: Impact of Acquisition Parameters and Image Quality | |
1Diagnostic and Interventional Radiology, Ulm University, Medical Center, Ulm, Germany, 2Section for Experimental Radiology, Ulm University, Medical Center, Ulm, Germany, 3Department of Pediatrics and Adolescent Medicine, Ulm University, Medical Center, Ulm, Germany |
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Tissue signal intensity ratio (SIR) has been used for a long time to determine liver iron concentration (LIC) based on gradient echo MRI. We studied the influence of acquisition parameters FA, RF spoiling and saturation regions, as well as image quality score, on the correlation of natural logarithm of SIR values to reference LIC obtained with spin echo. In our cohort of 85 patients, no significant influence on the slope of linear regression line was found, neither of acquisition protocol settings nor image quality, whereas the intercept was dependent on parameters influencing T1 sensitivity, namely FA and RF spoiling. |
| 2020 | Vascular Input Function Correction with Inflow Relative Enhancement Quantification in Liver DCE-MRI | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, People's Republic of China, 2Clinic for Radiology and Nuclear Medicine, Basel University Hospital, Basel, Switzerland, 3Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States, 4Department of Radiology, University of Washington, Seattle, WA, United States, 5Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 6Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 7Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States, 8Department of Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States |
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Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) with pharmacokinetic modeling can help to quantify the perfusion and function of liver. The accurate pharmacokinetic modeling relies on the accurately and reliably captured vascular input function (VIF)s. However, due to the fast blood velocity, the blood in the large vessels including abdominal aorta and the main branch of the portal vein experiences only a limited number of excitations and hasn’t reached a steady state. This introduces bias in the VIFs, and consecutively bias in pharmacokinetic parameters. In this study, we sought to correct the inflow effect on VIF acquisition in liver DCE-MRI. |
| 2021 | Gadoxetate disodium (Gd-EOB-DTPA) DCE-MRI of the Liver for the Assessment of Parenchymal Alterations in Primary Sclerosing Cholangitis | |
1Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg Eppendorf, Hamburg, Germany, 2Neuroradiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany, 3Internal Medicine, University Medical Center Hamburg Eppendorf, Hamburg |
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This study evaluates the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with Gd-EOB-DTPA for detection of hepatic inflammation/fibrosis in comparison to Ultrasound elastography in primary sclerosing cholangitis (PSC). |
| 2022 | Evaluation of Intravoxel Incoherent Motion with Different b Values in Patients with Hepatocellular Carcinoma | |
1Department of Radiology, Shanghai Institute of Medical Imaging, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China, 2Department of Radiology, Zhongshan Hospital, Fudan University, 3Siemens Healthcare, Shanghai, P.R. China |
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Intravoxel incoherent motion (IVIM) model provides both pure water motion and microcirculation by using multiple b values. IVIM imaging has been shown to be useful for assessment of liver diseases, including liver fibrosis and hepatocellular carcinoma. However, the clinical implementation of IVIM imaging is limited by long acquisition time. We compared IVIM imaging with different b-values to determine the combination of b-values in IVIM imaging that allows the relatively short acquisition time to obtain reproducible values of the IVIM parameters in patients with hepatocellular carcinoma. Our results showed at least 10b-values should be used in IVIM imaging for the assessment of hepatocellular carcinoma, and 5b-values IVIM imaging might increase errors in the perfusion-related f and D* values. |
| 2023 | Pancreatic MRI associated with pancreatic fibrosis and postoperative fistula: comparison between pancreatic cancer and non-pancreatic cancer tissues | |
1Department of Radiology, Gifu University, Gifu, Japan, 2Department of Pathology, Gifu University, Gifu, Japan |
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Pancreatic cancer (PC) occurs a histopathologically stronger pancreatic fibrosis compared to other non-PC. The risk factors of postoperative pancreatic fistula (POPF) were reported as soft or normal pancreatic parenchyma, and ampullary or duodenal disease. In this study, in patients with non-PC, frequency of POPF was greater due to lower grade of pancreatic fibrosis, and our results suggest that T1 signal and ADC value of the pancreas may link to the POPF. The T1 signal and ADC value of the pancreas may be a potentially useful imaging biomarker for the assessment of pancreatic fibrosis and POPF. |
| 2024 | Magnetic Resonance Imaging: Solid Pseudopapillary Neoplasm of the Pancreas, Mimics and Histopathological Correlation | |
1Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States |
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SPN is a rare epithelial neoplasm of low grade malignant potential for local and metastatic spread, occurring predominantly in young females. Differential diagnosis of SPN includes a wide spectrum of cystic and solid entities in the pancreas including pancreatic neuroendocrine, serous or mucinous cystadenoma or carcinoma, intrapancreatic splenules etc. Contrast enhanced MRI plays a key role in characterization of SPN and its mimics , helps to reach a specific diagnosis and narrows the differential, which is complimentary to EUS and biopsy when findings are equivocal to reach an accurate diagnosis which is of utmost importance for management and treatment planning |
| 2025 | Pancreatic changes in patients with liver cirrhosis and diabetes: a 3-T MRI evaluation | |
1Radiology, Kawasaki Medical School, Kurashiki city, Japan |
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The liver plays a pivotal role in glucose metabolism, so 60-80% of patients with cirrhosis experience impaired glucose tolerance and hyperinsulinemia, and 10-50% develop diabetes. This study was intended to clarify the extent to which pancreatic MRI findings are affected by the presence of diabetes mellitus in patients with liver cirrhosis. On 3-T MRI, size of the pancreas was significantly increased, the grade of pancreatic lobulation was significantly reduced, and pancreatic SIRs on T2WI with fat suppression were significantly increased in cirrhotic patients complicated with diabetes as compared to cirrhotic patients without diabetes. |
| 2026 | Evaluation of gravity effect on portal venous flow using multi-posture MRI | |
1Radiology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan, 2Division of Health Sciences, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Japan |
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Portal venous flow (PVF) seems to be affected by gravity, ie., it depends on the body posture. We validated the effect of gravity on PVF in supine and upright positions using an original multi-posture MRI. We compared maximum PVF, PVF velocity, PVF volume, and cross-sectional area of portal vein between supine and upright positions. The mean PVF velocity, PVF volume, maximum PVF, and cross-sectional area in the upright position were significantly lower than those in the supine position. Gravity reduces PVF velocity and volume, and these differences between postures potentially provide new diagnostic information. |
| 2027 | Pre-operative MRI quantification of hepatic fat and its correlation with histology, BMI and length of peri-operative stay following resection of liver metastases | |
1Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States |
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We correlate pre-operative quantification of hepatic fat on MRI in patients with colorectal cancer metastatic to the liver with the presence of fat on histology of the resected specimen, patient BMI and hospital length of stay. |
| 2028 | The effects of a 2 week hyperenergetic high carbohydrate or high fat diet on subcutaneous, visceral fat and metabolism | |
1Sir Peter Mansfield Imaging Centre,Physics and Astronomy, Nottingham University, Nottingham, United Kingdom, 2School of Life Sciences, Nottingham University, Nottingham, United Kingdom, 3NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals NHS Trust and University of Nottingham |
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With the rise in obesity globally, there is great interest in quantifying body composition and in particular metabolically active visceral adipose tissue (VAT). Increased accumulation of VAT has been linked with an increase in risk factors for cerebrovascular disease and Type 2 Diabetes (T2DM) . We investigated the degree to which weight, subcutaneous fat visceral fat, liver and lipid markers are affected by 2 weeks of overfeeding at 25% excess energy given as either carbohydrate or fat. 2 weeks of 25% excess energy overfeeding of either carbohydrate of fat does not alter subcutaneous or visceral abdominal fat in line with no changes in weight. MRI measurements of SAT and VAT can be used in longitudinal studies of diet to ascertain any changes in abdominal body fat deposition. |
| 2029 | Liver T1rho detects liver fibrosis without impact of fatty liver in patients with chronic hepatitis B: a prospective study | |
1Tianjin First Center Hospital, Tianjin, People's Republic of China, 2Philips healthcare, Beijing, People's Republic of China |
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This study investigated the merit of liver T1rho values for detecting fibrosis in patients with chronic hepatitis B and the potential impact of fatty liver on T1rho measurements. Eighteen healthy control subjects, eighteen patients with clinically diagnosed simple fatty and eighteen with liver fibrosis were underwent T1rho MRI and mDIXON-Quant. Mean T1rho values and fat fraction (FF) were compared among the three groups. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the merit of T1rho values for detecting liver fibrosis. T1rho values were correlated with FF and clinical data. Our results showed significant differences in T1rho values among the three groups and T1rho had moderate diagnostic efficacy to detect fibrosis. T1rho values were not correlated with FF, subject age, or body mass index. We conclude liver T1rho values can be used as a MR biomarker for liver fibrosis and are not influenced by fatty liver severity. |
| 2030 | Diffusion-Weighted Imaging and Variable Flip Angle T1 Mapping in Progression Assessment of Liver Fibrosis Caused by Hepatitis B Virus Infection: A longitudinal study | |
1Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China |
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Liver fibrosis caused by Hepatitis B virus (HBV) is a worldwide health problem. However, liver biopsy as the gold standard of diagnosing and evaluating therapy of liver fibrosis is an invasive examination with possible errors from sampling and intra- and inter-observer interpretation (1, 2). The non-invasive MRI may be a promising modality to evaluate the liver fibrosis. We used diffusion-weighted imaging (DWI) and variable flip angle (VFA) T1 mapping to explore the progression of liver fibrosis caused by HBV infection in a longitudinal study. |
| Exhibition Hall | Wednesday 8:15 - 10:15 |
| 2031 | Effect of fitting model on the accuracy of T2 and T2* magnetic resonance based liver iron concentration | |
1Radiology, Columbia University, New York, NY, United States |
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Literature has suggested mixed results regarding agreement between T2 relaxivity based liver iron concentration (LIC) and T2* relaxivity based LIC The purpose of the following study is to determine whether or not choice of relaxivity fitting models will impact the agreement of the results. |
| 2032 | Comparison of 2D and 3D Magnetic Resonance Elastography (MRE) Wave-Image Quality Across a Range of Body Mass Indices | |
1Radiology, Liver Imaging Group, University of California, San Diego, San Diego, CA, San Diego, CA, United States, 2Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of California, San Diego, San Diego, CA, 3Gastroenterology, Rady Children's Hospital San Diego, San Diego, CA, 4NAFLD Translational Research Unit, Division of Gastroenterology, University of California, San Diego, La Jolla, CA, 5Radiology, University of Wisconsin - Madison, Madison, WI, 6Medical Physics, University of Wisconsin - Madison, Madison, WI, 7Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, 8Medicine, University of Wisconsin - Madison, Madison, WI, 9Emergency Medicine, University of Wisconsin - Madison, Madison, WI, 10Radiology, Mayo Clinic, Rochester, MN |
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This analysis of 129 adults compared the |
| 2033 | Gadolinium-enhanced high-flip-angle R2* mapping enables estimation of a greater range of R2* values | |
1Liver Imaging Group, Department of Radiology, University of California, San Diego School of Medicine, San Diego, CA, United States |
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The range of R2* values estimated from MR sequences using low flip angles (FA) is limited by the background signal decay. The administration of contrast allows the use of higher FAs and increases the signal to noise ratio (SNR), allowing the estimation of a greater range of R2* values. We compared pre- and post-contrast R2* values in 158 patients and observed large discrepancies at R2* values greater than 300s-1. Our findings suggest that in patients with severe iron overload, post-contrast high-FA R2* mapping may be the preferred sequence for iron quantification. |
| 2034 | Comprehensive dynamic contrast-enhanced 3D MR imaging of the breast with fat/water separation and high spatiotemporal resolution using Dixon Radial Volumetric Encoding (Dixon-RAVE) | |
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 |
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Conventional clinical breast MRI consists of several separate T1-weighted scans, including both pre-contrast fat-suppressed and non-fat-suppressed acquisitions as well as the acquisition of dynamic contrast-enhanced phases. Here, we show how this entire exam can be replaced by a single comprehensive scan, therefore reducing overall scan time and simplifying the clinical workflow. This is achieved by using radial stack-of-stars sampling in combination with a model-based fat/water separation technique, which takes into account the off-resonant blurring of fat and integrates both compressed sensing and parallel imaging. The approach is validated in 24 patients and results were evaluated by two radiologists. |
| 2035 | Free-Breathing Hepatobiliary Phase Imaging: Comparison of Five Free-Breathing Scans with Conventional Breath Hold Scan | |
1Radiology, Gifu University Hospital, Gifu City, Japan, 2Philips Healthcare, Tokyo, Japan, 3Philips Electronics Japan, Tokyo, Japan |
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We applied five free-breathing scan sequences to gadoxetic acid-enhanced hepatobiliary phase imaging. Breath hold eTHRIVE demonstrated the highest SNR on the liver, although it is also revealed the disadvantage for the patients with unstable breath hold. On the other hand, free-breathing 3D VANE with gate and track demonstrated the highest image quality with equivalent SNR to breath hold eTHRIVE. It is notable that free-breathing 3D VANE produced steady and effective image quality for all patients regardless of breath hold ability. |
| 2036 | BOLD MRI of Activated Human Pancreas | |
1Radiology, Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, People's Republic of China |
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Glucose ingestion activates the pancreatic functions and increases the oxygen consumption, we hypothesized that BOLD MRI could detect the alterations during the glucose challenge. BOLD MRI was performed in 12 volunteers before and after glucose ingestion. A transient but significant decrease in pancreatic T2* values was observed after glucose ingestion. BOLD MRI may serve as a non-invasive tool to detect the activation of human pancreas. |
| 2037 | Intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) for differential diagnosing hepatocellular carcinoma (HCC) from hepatic hemangioma (HHA). | |
1The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China, 2MR Research, GE Healthcare, Beijing, People's Republic of China |
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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. DKI adapts a kurtosis based model to depict the non-Gaussian diffusion process, which could be caused by the presence of different barriers in cellular complex structures (e.g. cell membranes and organelle compartments).Initial application of DKI focused on neuroimaging, Recently, it has also been reported that DKI may help to assess response to treatment in HCC. Comparing the IVIM and DKI parameters between carcinoma (HCC) and hepatic hemangioma(HHA) we found that IVIM and DKI can supply many meritorious parameters, combining with the IVIM and DKI may help in increasing the sensitivity and specificity of antidiastole. |
| 2038 | Abdominal Fast Advanced Spin Echo Diffusion-Weighted Imaging | |
1Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan, 2Center of Radiology and Radiation Oncology, Kobe University Hospital, Kobe, Japan, 3Toshiba Medical Systems Corporation, 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. FASE-DWI improved distortion and showed equivalent diagnostic performance and be used as an alternative to EPI-DWI. |
| 2039 | Computed Diffusion-Weighted Image for Abdominal MRI | |
1Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Japan, 2Center of Radiology and Radiation Oncology, Kobe University Hospital, Kobe, Japan, 3Toshiba Medical Systems Corporation, Otawara, Japan, 4Radiology, Kobe University Graduate School of Medicine, Kobe, Japan |
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The purpose of this study was to assess capability of computed DWI in evaluation of various abdominal diseases. We found cDWI can improve image quality and malignant lesion contrast, conspicuity, and detection. cDWI is a useful post-processing tool for abdominal MRI. |
| 2040 | Optimisation for Pulmonary R2* Quantification and Repeatability Evaluation | |
1Radiotherapy and Imaging, The Institute of Cancer Research, Surrey, United Kingdom |
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In 5 patients with lung cancer, UTE-MRI was used to derive pulmonary R2* in lung and establish its repeatability. Plausible R2* values were obtained only when using TEs of 0.08 and 0.2 ms: higher TEs produced implausible mean negative R2* within individual patients and a cohort R2* not significantly different from zero, due to lack of signal decay beyond TE=0.2ms. Pulmonary R2* values derived using TEs of 0.08 and 0.2ms were higher than prior reports where longer echo-times were employed. Test-retest limits-of-agreement were +90.5%to -47.5% indicating that a 90% increase in R2*is required post-radiotherapy to reliably demonstrate radiation-induced change. |
| 2041 | Initial Experience of MR Elastography Using Spatially Selective Excitation for the Pancreas. | |
1Diagnostic Radiology & Nuclear Medicine, Hamamatsu University school of Medicine, Shizuoka, Japan, 2Fundamental Development for Advanced Low Invasive Diagnostic Imaging, Nagoya University Graduate School of Medicine, Nagoya, Japan, 3Radiology, Hamamatsu University Hospital, Shizuoka, Japan, 4GE Healthcare Japan, Tokyo, Japan |
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We tried reduced-FOV MR elastography using a local excitation technique called FOCUS for the pancreas. Comparing conventional-MRE with FOCUS-MRE, there was no significant differences of the measurable are of pancreas. In both methods, the higher the body mass index was, the smaller the measurable area of the pancreas. |
| 2042 | Test-Retest Repeatability of MR Elastography (MRE) Stiffness Measurements of Liver Phantoms | |
1Radiology, Mayo Clinic, Rochester, MN, United States |
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All the previous test-retest human liver MRE studies could involve physiological stiffness change . In this study, our goal was to evaluate MRE test-retest repeatability with liver phantoms to avoid the possible influence of physiological changes in humans. We hypothesized that the variations of test-retest MRE stiffness measurements of phantoms were smaller than that of human livers. |
| 2043 | The assessment of gallstones using three dimensional ultra-short echo time in vivo | |
1Radiology, Seirei Mikatahara General Hospital, Hamamatsu, Japan, 2Fundamental Development for Advanced Low Invasive Diagnostic Imaging, Nagoya University, Graduate School of Medicine, 3Seirei Mikatahara General Hospital, Hamamatsu, Japan, 4Philips Electronics Japan, Ltd., Tokyo, Japan, 5Radiology, Hamamatsu University School of Medicine, Hamamatsu, Japan |
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First clinical study using 3D dual echo UTE sequence for suspected gall stone patients was performed. All gallstones were able to be detected as positive signal in-vivo. Our study may indicate that UTE has an added value of depicting impacted stones or hepatolithiasis as positive signal. |
| 2044 | Magnetic resonance elastography for uterine fibroids | |
1University of Yamanashi, Chuo, Japan |
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We evaluated the feasibility of magnetic resonance elastography (MRE) for uterine fibroids and the effect of imaging sequences (i.e., spin-echo echo-planar imaging [SE-EPI] and gradient-echo [GRE]) on stiffness measurements. All MRE were performed in two cross-sectional planes (i.e., axial and sagittal). SE-EPI-MRE showed lower fibroid stiffness values than GRE-MRE. Each MRE method is a valid and reliable technique for measuring the stiffness of uterine fibroids. |
| 2045 | MRI to evaluate the response of the locally advanced cervical cancer to CCRT: MRS(magnetic resonance spectroscopy), DWI(diffusion weighted image), and T2WI | |
1Radiology, Mokdong Hsopital, EWUMC, Seoul, Korea, Republic of, 2Radiology, Mokdong Hospital, EWUMC, Seoul, Korea, Republic of |
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MRS(MR Spectroscopy) as well as T2Wi, and diffusion weighted images may be used to evaluate the response of LACC to CCRT. |
| 2046 | Comparative analysis of image in changing breath hold method of B1 calibration at 3.0T abdomen MRI | |
1Radiology, Seoul National University Bundang hospital, Gyeonggi-do, Korea, Republic of, 2Radiology, Seoul National University Bundang Hospital, Seongnam, Korea, Republic of |
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Evaluation of image analysis according to changing breath hold methods of B1 calibration . |
| 2047 | Using 2D-PACE to trigger scan and supervise motion on Breath-Hold imaging | |
1Siemens Shenzhen Magnetic Resonance Ltd, Shen Zhen, People's Republic of China |
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A simple 2D pace module was implemented in a Breath-Hold imaging work flow to trigger the normal scan and supervise the motion. Our preliminary experiments show that within the newly added module, images are more immune to respiratory motion artifacts and the detail of small structures are clearer. |
| 2048 | Quiet Motion-Robust Technique for 4D T1-Weighted Fat-Suppressed Abdominal Imaging | |
1Global MR Applications and Workflow, GE Healthcare, Madison, WI, United States, 2Global MR Applications and Workflow, GE Healthcare, Hino, Japan, 3Global MR Applications and Workflow, GE Healthcare, Houston, TX, United States, 4Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States |
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Acoustic noise generated by MR systems represents one of the major barriers to patient comfort, particularly for the pediatric population. Reducing the slew rate of the gradient field is one way to effectively decrease acoustic noise; however, this comes at the expense of scan time. For breath-hold abdominal imaging, longer scan times mean a more stressful breath-hold for the patient, reduce temporal resolution for multi-phase imaging, and may allow for more motion artifact due to suboptimal breath-holding. This work describes an accelerated 3D multi-phase technique compatible with fat saturation for both quiet and motion-robust abdominal imaging. |
| 2049 | High-resolution 3D lung 1H-MRI in rodents at 9.4T with an optimized multi-echo gradient echo sequence | |
1Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 2MRI Clinical and Translational Research Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States |
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Preclinical MR lung imaging has been challenging due to lower tissue density compared to other organs. Current practice has been 2D spin-echo or gradient echo with relatively lower resolution. In this work we present an optimized high resolution 3D Multi Gradient Echo and demonstrate the results by comparing it with state of the art 2D Gradient echo. |
| 2050 | Receiver operating characteristic analysis of fat-fraction is effective in differentiating identifying an optimal threshold to differentiate between brown and white adipose tissue ex vivo and in situ in rats using 3-point IDEAL MRI | |
1Department of Radiology, University Hospitals Coventry & Warwickshire NHS Trust, Birmingham, United Kingdom, 2Warwick Medical School, University of Warwick, Coventry, United Kingdom, 3Department of Endocrinology, University Hospitals Coventry & Warwickshire NHS Trust, Birmingham, United Kingdom, 4Medical Physics, University Hospitals Coventry & Warwickshire NHS Trust, Coventry, United Kingdom |
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Brown adipose tissue (BAT) has lower fat content than white adipose tissue (WAT), which has been exploited using Dixon-based MRI to identify BAT. We sought to identify the optimal threshold to differentiate between BAT and WAT in rats on the basis of fat fraction. Fat fraction within BAT was significantly lower than WAT in rodents. Receiver operating characteristic analysis showed that differentiating BAT and WAT on the basis of fat fraction had excellent accuracy in both ex vivo and in situ. The optimal cut-off to separate BAT and WAT was significantly lower in rats exposed to cold, likely secondary to lipolysis. |
| 2051 | Cyclic Changes of the Boundary Sharpness of Uterine Zonal Structures Visualized by High-resolution T2-weighted Images in Young and Middle-aged Females during the Menstrual Cycle | |
1Radiology, Peking Union Medical College Hospital, Beijing, People's Republic of China, 22. MR Collaboration NE Asia, Siemens Healthcare, Beijing, People's Republic of China, 3OB&GYN, Peking Union Medical College Hospital, Beijing, People's Republic of China |
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This study aimed to demonstrate the cyclic changes of the boundary sharpness of uterine three zonal structures of young and middle-aged women on 3T using a 3D T2-weighted SPACE sequence during the menstrual cycle. Peri-ovulatory phase exhibited the clearest boundary sharpness of corpus zonal structures following by FP, LP and MP, while that of the cervix were almost well-defined during the menstrual cycle. |
| 2052 | Resistance and susceptibility to diabetes - characterising the ‘Thin on the Outside Fat on the Inside’ (TOFI) profile using magnetic resonance imaging: a pilot study in Asian and Caucasian women | |
1Human Nutrition Unit, School of Biological Sciences, University of Auckland, Auckland, New Zealand, 2Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand |
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Prediction of risk for dysglycaemia and adverse metabolic health is difficult, with some outwardly lean individuals having greater susceptibility to type 2 diabetes (T2D) than obese resilient individuals. Using 3T MR Imaging and spectroscopy we showed, in 10 Asian Chinese and 6 European Caucasian healthy or prediabetic women (18 – 70 years and BMI 25 – 50 kg/m2), that greater storage of fat within riskier ectopic sites, i.e. pancreas and liver, may in part explain the reported increased risk of T2D in Asian Chinese populations compared to their Caucasian counterparts at the same BMI and younger age. |
| 2053 | Parameter Optimization for Non-contrast-enhanced Renal MR Angiography and Its Age-dependent Preliminary Study | |
1the First Hospital of China Medical University, Shenyang, People's Republic of China |
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Our purpose was to investigate the feasibility of NCE-MRA using Time-SLIP technique on healthy volunteers by determining the optimized TI value and its preliminary relationship with age as well. 61 healthy volunteers were recruited and divided into two age groups. The acquired data using six differernt TIs sequences were measured and analyzed to get three parameters including VKR, grade of renal artery branches and grade of imaging quality. In conclusion, the Time-SLIP technique is able to obtain renal MR angiography with optimized TI value 1500ms. Moreover, the age of individual subjects can affect the optimized TI value. |
| 2054 | A new technique of SPIO-enhanced MRI: delayed recovery of T2*-weighted signal intensity as a novel diagnostic marker for visualization of irradiated liver parenchyma. | |
1Division of Functional Imaging, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, Kashiwa, Japan, 2Department of Radiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan, 3Department of Radiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan |
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Visualization of irradiated liver parenchyma may assist safety margin assessment in radiotherapy. We demonstrate that an MR imaging technique has the ability to visualize irradiated liver parenchyma after 30-Gy irradiation in a tumor-bearing rat model. In this technique, superparamagnetic iron oxide (SPIO) is administered to label Kupffer cells (KCs) before, rather than after irradiation. A dose of 30-Gy is a lower, more clinically relevant dose than that used in the previous studies. Our results suggest that 30-Gy irradiation delays the recovery of hepatic T2*-weighted signal after SPIO administration. Presumably, irradiation delays degradation process of SPIO in the KCs. |
| 2055 | Changes in fat distribution and composition during ketogenic diet investigated by MRI and MRS. | |
1Medical Physics, Department of Radiology, Medical Center – University of Freiburg, Freiburg, Germany, 2Medical Center – University of Freiburg, Freiburg, Germany, 3Department of Medicine I, Section of Clinical Nutrition and Dietetics, Medical Center – University of Freiburg, Freiburg, Germany |
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Changes in fat distribution and composition during ketonic diet were investigated in a sub group of twelve volunteers of a larger study. Liver fat concentrations in the examined cohort turned out to be surprisingly low compared to patient cohorts with similar BMI measured in other studies. The hypotheses that intra-hepatic fat may be reduced during a ketogenic diet could not be confirmed. However the composition of the sub group may have biased the outcome. While the MRI protocol and analysis worked well, MRS analysis of data acquired with the given protocol in subjects with low hepatic fat reaches its limitations. |
| 2056 | Ethnic variation in body composition of men with type 2 diabetes from automated analysis of Dixon MRI | |
1Guy's & St. Thomas NHS Foundation Trust, London, United Kingdom, 2Klarismo Ltd, 3Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 4Diabetes & Nutritional Sciences Division, King's College London, London, United Kingdom |
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This work explores the role of body composition and its relationship with the development of type 2 diabetes in White European and Black African men. An investigation of differences in body composition between these two groups was performed via automated image segmentation and analysis of Dixon MR images. Our initial results suggest visceral adipose tissue may not be a principal determinant in the development of type 2 diabetes in Black African men as it is with White European men. |
| 2057 | Quantitative MRI parameters for adipose tissue characterization in obese patients | |
1Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany, 2Integrated Research and Treatment Center (IFB) AdiposityDiseases, Leipzig University Medical Center, Leipzig, Germany, 3Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Division of Bariatric Surgery, Leipzig University Hospital, Leipzig, Germany |
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In obesity research and clinical practice, disease progress or response to therapy is typically evaluated by the reduction of body weight, adipose tissue (AT) volume or comorbidity remission rates. However, little is currently known about therapy-induced changes in subcutaneous and visceral AT composition and how to quantify them. Lean control subjects had recently been shown to have significantly higher T1 relaxation times in both SAT (301 ms) and VAT (360 ms) than severely obese patients (275 and 294 ms, respectively). Aims of this study were to characterize AT by quantitative MRI and evaluate the intra-individual changes at two time points. |
| 2058 | The investigation of the relationship between obstetrical risk factors and pelvic floor injuries: a MRI-based study | |
1Tianjin First Center Clinical College, Tianjin, People's Republic of China |
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Vaginal childbirth is an important cause to pelvic floor injuries. In this study, we aim to identify various forms of the injuries and the association with obstetrical risk factors in primiparous women. The results showed that there were significant differences about the proportions of various patterns of the pelvic floor injuries and the severity of LAM injuries between the groups with and without obstetrical risk factors. |
| 2059 | Phosphorus MRSI reveals subtle changes in metabolic profile of hepatic tissue in insulin resistant population. | |
1Endocrinology & Metabolism, Internal Medicine III, Medical University of Vienna, Wien, Austria, 2High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Wien, Austria, 3Clinical Molecular Imaging, Karl Landsteiner Institute, Wien, Austria |
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This study employed ultra-high field (7T) 1H and 31P MRS for the characterization of subtle hepatic tissue changes in insulin sensitive and insulin resistant group of healthy volunteers. Hepatic lipids, the forward rate of ATP synthesis and profile of metabolites containing 31P were assessed. Decreased inorganic phosphate was found in the subgroup of volunteers with increased hepatic fat accumulation and increased phosphocholine was found in the insulin sensitive subgroup. Concentration of 31P containing metabolites found here are well within the range of previous publications and subtle differences point towards their role in pathophysiology of metabolic syndrome and/or hepatic steatosis. |
| 2060 | Renal perfusion is decreased in kidneys with multiple renal arteries as demonstrated by renal DCE MRI | |
1Center for Image Sciences, University Medical Center Utrecht, Utrecht, Netherlands, 2Nephrology, University Medical Center Utrecht, Utrecht, Netherlands, 3Radiology, University Medical Center Utrecht, Utrecht, Netherlands |
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The presence of multiple renal arteries per kidney is associated with hypertension. The smaller vessel diameter is thought to lead to decreased renal perfusion, which activates the renin-angiotensin-aldosterone system (RAAS), resulting in increased systemic blood pressure. We measured renal blood flow (RBF) using dynamic contrast enhanced (DCE) MRI to investigate the relation between number of renal arteries, RAAS activity and RBF. The number of renal arteries was associated with reduced RBF and increased RAAS activity. In all patients, we observed that reduced RBF was associated with increased RAAS activity. |
| 2061 | Development of a lesion-wise metric for evaluation of predictive models of prostate cancer on multiparametric MRI | |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN |
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A novel lesion-wise metric was developed to evaluate the quality of predictive models of prostate cancer that use quantitative multiparametric MR data to perform prediction on a voxel-wise basis. The metric is based on the Jaccard similarity coefficient and emphasizes overlap and co-localization of ground truth and predicted lesions. Experiments to characterize the metric demonstrated that it qualitatively reflected the goodness of predictions and was more accurate and informative than voxel-wise measures of sensitivity and specificity. We propose that the metric may be customized to select the best predictive models for specific clinical applications such as performing targeted prostate biopsies. |
| 2062 | Why is the Peripheral Zone of the Normal Human Prostate High in ADC Value and T2-Weighted Signal Intensity? | |
1Centre for Medical Imaging, University College London, London, United Kingdom, 2Centre for Medical Image Computing, University College London, London, United Kingdom, 3Research Department for Tissue & Energy, University College London, London, United Kingdom, 4Department of Pathology, University College London Hospital, University Street, United Kingdom, 5Department of Urology, University College London Hospital, London, United Kingdom, 6Francis Crick Institute, University College London, London, United Kingdom, 7Discipline of Medical Radiation Sciences, University of Sydney, Sydney, Australia |
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The biophysical basis of MRI signal in the normal human prostate is uncertain, whereby the normal peripheral zone has high ADC values and returns high signal on T2-weighted imaging. In this study, we use MRI in combination with quantitative digital histopathology to offer an explanation. Paired scans were performed at 3T on a human prostate, prior to and following prostatectomy and changes in zonal morphology and MRI characteristics were measured. The peripheral zone collapsed and reduced in T2 signal intensity and ADC value ex-vivo. Digital histopathological analysis suggested the peripheral zone stores more ejaculatory fluid than the transition zone. |
| 2063 | Coronal View Renal Perfusion FAIR-ASL Measurements in Mice | |
1Department of Physics, University of Würzburg, Würzburg, Germany, 2Department of Internal Medicine I, Division of Cardiology, University Hospital Würzburg |
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Renal perfusion measurements in coronal view using FAIR-ASL can be problematic in small animals as the selective inversion slice can label a large fraction of the inflowing blood. In this work, an alternative orientation for the selective inversion slice is shown to increase the sensitivity of the measurement. |
| Exhibition Hall | Wednesday 8:15 - 10:15 |
| 2064 | Diagnostic accuracy of 3-T magnetic resonance imaging with Star VIBE: versus computer tomography in pulmonary nodules | |
1The first affiliated hosptial of Shaanxi traditional chinese medical university, Xian Yang, People's Republic of China |
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Star VIBE (MRI) sequence in obtaining scan under free breathing can provide high-resolution imaging. Therefore, we assessed the accuracy of magnetic resonance imaging (MRI) for detecting pulmonary nodules by comparing the detection rate of high-resolution Star vibe sequence with the MSCT results. We concluded that pulmonary nodules with the maximum diameter more than 3mm can be detected by star-vibe (MRI) sequence with a satisfactory accuracy. Although pulmonary nodules with the max diameter less than 3mm had relatively low sensitivity, the accurate treatment decisions may also be made. |
| 2065 | Histogram analysis of pharmacokinetic parameters of DCE-MRI: differentiating malignant from benign solitary pulmonary nodules | |
1Nantong Tumor Hospital, Nantong, People's Republic of China, 2Nantong Tumor Hospital, 3Shanghai East Hospital |
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A histogram analysis approach has been shown to be a premising tool in discriminating malignant and benign SPNs in terms of their heterogeneity. The purpose of our study was thus to primarily assess the diagnostic performance of DCE-MRI for stratifying the malignant and benign using histogram analysis. The results showed that the mean value of Ktrans and Kep, Kurtosis and skewness assessments from Ve of DCE-MRI histograms may be useful for differentiating malignant from benign SPNs. |
| 2066 | A case-based approach to MR imaging patterns of cholangiocarcinoma and post-intervention features | |
1Radiology and Imagining Sciences, Emory University School of Medicine, Atlanta, GA, United States, 2Radiology, Medical Univeristy of South Carolina |
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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. |
| 2067 | Treatment Response of Target Tumors and Its Impact on Local Control in Patients with Hepatocellular Carcinoma after Stereotactic Ablative Radiotherapy: Serial Changes of MRI Measurements | |
1Tri-Service general hospital, Taipei, Taiwan |
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Functional imaging techniques have a potential role in evaluation of treatment response in patients with HCC after SABR. After SABR, the increase of ADC value > 10% had marginally improved local control. A further large-scale study to identify the predictive value of parameters in functional MRI in validated. |
| 2068 | Diagnostic Value of Calculated High B Value DWI for Prostate Cancer Detection | |
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Department of Urology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 3Olea Medical |
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We compared image quality, lesion conspicuity and diagnostic performance of calculated and acquired b1600 DW images for prostate cancer (PCa) detection and assessed the added value of calculated b2000 images for PCa detection. We showed that calculated b1600 had equivalent image quality and diagnostic performance for PCa detection compared to acquired b1600 images with improved tumor-to-PZ contrast ratio, which suggests that calculated b1600 could be an alternative to acquired b1600 to decrease acquisition time. We also showed that calculated b2000 had better tumor conspicuity than b1600. |
| 2069 | Impact of an additional endorectal imaging coil on MR image quality and cancer detection in the prostate | |
1Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany, 2Institute of Pathology, University of Leipzig, Leipzig, Germany, 3Urology Department, Leipzig University Hospital, Leipzig, Germany |
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Multiparametric MRI has been shown to improve detection, localization and characterization of patients with suspected prostate cancer (PCa). The current PIRADS guideline (v2, 2015) states that the additional use of an endorectal imaging coil (ERC) increases SNR at any magnetic field strength which may be particularly useful for staging and inherently lower SNR sequences (DWI or DCE). On the other hand, phased array coils with 16 or more elements may also provide adequate SNR. This work assesses the potential benefit of an ERC for the detection of prostate cancer– within the same patients. |
| 2070 | An mpMRI derived Logistic Regression Model for Gleason 4 Pattern Prediction in Peripheral Zone Prostate Cancer | |
1Translational Imaging Group, CMIC, University College London, London, UK, London, United Kingdom, 2Centre for Medical Imaging, University College London, London, UK, London, United Kingdom, 3Dementia Research Centre, Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK, 4Academic Radiology, University College London Centre for Medical Imaging, London, UK |
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Gleason grade is the most important determinant of prognosis and survival in prostate cancer, and is determined using prostate biopsy. Here we investigate whether multi-parametric MRI can be used to classify Gleason grade non-invasively with logistic regression (LR) models, classifying tumours into 3+3 and those containing a 4 component. A selection of clinical and quantitative MRI metrics were used. The LR model was trained in ninety-nine patients and tested following a Leave-One-Out (LOO) analysis on a temporal separated cohort of nineteen patients. LR models were shown to predict the presence of Gleason 4 component in cancer lesions both before and after LOO analysis. |
| 2071 | Evaluation of T1/T2 ratios in a pilot study as a potential biomarker of biopsy - proven benign and malignant breast lesions in correlation with histopathological disease stage. | |
1Surgery, Boston University, Boston, MA, United States, 2Radiology, Boston Medical Center, Boston, MA, United States, 3Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, 4Biostatistics, Boston University, Boston, MA, United States |
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The T1/T2 ratios obtained by qMRI provide measures that strongly correlate with histopathological findings. This quantitative information of tissue properties can provide basis for improving the specificity of diagnostic breast imaging and serve as a tool to assess response to treatment and contralateral breast involvement. |
| 2072 | Using preoperative MRI to prevent unnecessary lymphadenectomies in patients with grade 1 endometrial cancer decreases operating room times and post-operative complications. | |
1Radiology, University of Wisconsin, madison, WI, United States, 2Radiology, University of Wisconsin, WI, 3OBGYN, University of Wisconsin, WI |
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MRI can exclude myometrial invasion (MI) and cervical invasion (CI) with high accuracy in endometrial carcinoma. Women with small tumors, no MI, no CI and no evidence of extra-uterine spread have a very low risk of lymph node metastasis, and lymphadenectomy can be avoided. The goal of our study was to demonstrate how using preoperative MRI to prevent unnecessary lymphadenectomy can affect operating room time (OR) and post-operative complications. We performed an IRB approved retrospective study evaluating MRI results, lymphadenectomy status, operative times, and post-operative complications. This demonstrated a statistically significant decrease in OR times and post-operative complications. |
| 2073 | Assessment of intravoxel incoherent motion diffusion-weighted MR imaging in solitary pulmonary nodules : comparison and correlation with dynamic contrast-enhanced MR imaging. | |
1Radiology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, People's Republic of China, 2Radiology, Tongji Hospital of Huazhong University of Science and Technology, Wuhan, People's Republic of China |
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The study aim to compare the intravoxel incoherent motion (IVIM) and DCE-MRI for distinguishing benign pulmonary nodules and lung cancer and evaluate the diagnostic performance of two methods. We found ADCtotal,D,D*from IVIM and Tmax,SLE from DCE-MRI valuable for differential diagnosis ,with D and Tmax have better sensitivity and accuracy.But parameters between the two methods show poor correlation.Combination of IVIM and DCE-MRI can get excellent diagnostic performance. |
| 2074 | Variable Refocusing Flip Angle Single-Shot Fast Spin Echo Imaging of Liver Lesions: Improved Lesion Contrast and Speed | |
1Radiology, University of California, San Francisco, San Francisco, CA, United States, 2Radiology, Stanford University School of Medicine, Stanford, CA, United States |
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Variable refocusing flip angle single-shot fast spin echo (vrfSSFSE) decreases T2-decay related blurring, allows increased K-space coverage while maintaining clinically relevant echo times, and reduces specific absorption rate. We evaluated clinical image quality and acquisition time of vrfSSFSE for imaging liver lesions in comparison with conventional SSFSE in patients undergoing 68Ga-DOTA-TOC PET on a 3T time-of-flight PET/MRI. Quantitative analysis of 53 lesions in 27 patients demonstrated higher mean CNR with vrfSSFSE (9.9 vs. 6.7, p<0.001) and 1.7-fold increase in speed compared to SSFSE. vrfSSFSE improves liver lesion contrast with shorter scan times acquired using a single 20 second breath hold. |
| 2075 | Reduction of the variation in parameter estimation from atypical signal intensity decay or its variation near tumor in low b factors using a ROI-based analysis method in IVIM model for prostate diffusion imaging | |
1Radiology, Seoul National University Hospital, Seoul, Korea, Republic of |
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In an IVIM technique, atypical signal intensity decay in low b factors or its variation at neighboring pixels at tumor lesion may be caused by tumor heterogeneity or spatial mismatch due to image distortion in EPI sequence, which can make estimated IVIM parameters be unreliable in conventional pixel-by-pixel method. Thus, to obtain more reliable IVIM outputs for prostate IVIM MR imaging, we suggest a new and simple ROI-based analysis method using all data of surrounding pixels in estimation and our study demonstrates a ROI-based analysis method decreased variation in IVIM parameters and can provide more reliable IVIM map images. |
| 2076 | Prediction of low-risk breast cancer using quantitative DCE-MRI and its pathological basis | |
1Department of Radiology, Tenth People’s Hospital,TongjiUniversity School of medicine, Shanghai, Shanghai, People's Republic of China |
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Purpose: This study aimed to evaluate the difference in dynamic contrast enhanced magnetic resonance imaging characteristics between low-risk and non-low-risk breast cancers and to explore the possible pathological basis. Materials and methods: Approval from the institutional review board and informed consent were acquired for this study. The MR images of 104 lesions with pathologically proven breast cancer were retrospectively analyzed. Result: Low-risk tumors showed significantly lower Ktrans and Kep values and higher ADC value than non-low-risk breast cancers. Conclusion: The prediction parameter using Ktrans, Kep, and ADC obtained on DCE-MRI and diffusion-weighted imaging could facilitate the identification of low-risk breast cancers. |
| 2077 | Using ngram-based features to explore the correlation of prostate MR findings and PI-RADS classification | |
1Peking University First Hospital, Beijing, People's Republic of China, 2Philips Research China, Shanghai, People's Republic of China |
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The decision tree trained on MR descriptions by natural language processing (NLP) method represents a desirable performance in identifying low-risk PI-RADS 2-3 classes with high precision and high-risk PI-RADS 5 class with high recall. From the decision path, several specific features are adopted to make decision and the identification of key indicator contributes to distinguish PI-RADS 2 class from PI-RADS 3 class. |
| 2078 | "Push-button" PET/MRI using a continuous scan 3D quantitative T2 MRI sequence | |
1Biomedical Engineering, King's College London, London, United Kingdom, 2Siemens Healthcare Limited, Frimley, United Kingdom, 3Cancer Imaging, King's College London, London, United Kingdom |
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To avoid overtreatment and repeated use of invasive biopsies, there is a need for improved diagnostic tools for prostate cancer risk stratification. Simultaneous Positron Emission Tomography / Magnetic Resonance Imaging (PET/MRI) systems are promising, however, fundamental differences in PET and MR imaging methodology currently limit full integration and thus the true potential of simultaneous PET/MR: While PET is a rather straightforward, single 3D scan, the MRI exam is complex and current clinical practice consists of several 2D sequences with different image contrast weightings and spatial coverage, performed in a serial fashion. Here, we propose a single, 3D, quantitative T2-MRI sequence that parallels the continuous scan workflow of PET data acquisition. |
| 2079 | Prostate Cancer: Differentiation of Transition Zone Cancer from Benign Prostatic Hyperplasia by Using Diffusion Kurtosis imaging, Intravoxel Incoherent motion and ultra-high b-value apparent diffusion coefficient techniques | |
1Chinese PLA General Hospital, Beijing, People's Republic of China, 2Chinese PLA General Hospital, People's Republic of China, 3Chinese PLA General Hospital |
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To evaluate the value of the (kurtosis, perfusion and diffusion) parameters in the differentiation of TZ cancer from benign GH.30 patients underwent preoperative 3-T magnetic resonance (MR) imaging. Each parameter in TZ carcinomas and GH were compared using Student's t test, receiver operating characteristics (ROC) analysis. All parameters except for D* in TZ carcinoma and GH were significantly different, and showed the same sensitivity for differentiating TZ carcinoma from GH (92.3%), and K and ADCs with equal specificity (96.7%).The monoexponential ultra-high b value ADC calculation is more practical to discriminate TZ carcinoma from GH. |
| 2080 | Differential Diagnosis of Ovarian Tumor and Degenerated Subserous Leiomyoma Using Diffusion-tensor Imaging | |
1Department of Radiology, the First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China, 2GE healthcare China, Beijing, People's Republic of China |
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Ovarian cancer is one of the most common malignant tumor of female reproductive organs, which is the first cause of death in gynecological malignancies. A mixed cystic and solid appearance of an ovarian mass is usually difficult to differentiate from degenerated subserous leiomyoma. In this study, DTI MR measurements were performed to investigate the difference of the ADC and FA values in ROIs of the soild component region between ovarian tumors and uterine fibroids. |
| 2081 | Improved lymph node staging using MRI mDixon fat fraction measurements in patients with intermediate and high-risk prostate cancer | |
1UCL Centre for Medical Imaging, London, United Kingdom, 2Medical Physics, University College London Hospital, London, United Kingdom, 3Institute of Nuclear Medicine, University College London Hospital, London, United Kingdom |
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The staging of lymph nodes in prostate cancer is important for the planning and monitoring of treatments. However, there is currently a paucity of techniques that can accurately identify the presence of metastases in small nodes. In this study, we investigate the usefulness of signal fat fraction from MRI mDixon acquisitions in discriminating between benign and metastatic nodes using 18F-Choline PET as a reference standard. We present data suggesting that in comparison to commonly used diameter measurements, mDixon fat fraction may be better at discriminating benign from involved lymph nodes that are <10mm in short axis diameter. |
| 2082 | The Histogram analysis of quantitative Dynamic enhanced and Diffusion-weighted Intravoxel Incoherent Motion MRI for pathologic Gleason grading of prostate cancer | |
1Department of imaging, The second affiliated hospital of Soochow university, Soochow, People's Republic of China, 2The second affilicated hospital of Soochow university, soochow, People's Republic of China, 3The second affilicated hospital of Soochow university, People's Republic of China, 4GE healthcare China |
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There are different treatments for low-risk and high-risk prostate cancer patients in clinical, NCCN guidelines recommend proactive monitoring management as the preferred treatment for patients with low risk PCa（GS ≤6 ）,and active measures for intermediate/high-risk patients. Our research found that both DCE and IVIM quantitative parameters Histogram analysis results can successfully distinguish LG from HG PCa ,and their diagnostic performance was not statistically significant. Considering the method we used to acquire quantitative parameters of DCE-MRI , IVIM may provide us a new way for those who cannot bear the invasive intravenous injection of contrast agent . |
| 2083 | Association of breastfeeding duration with abdominal fat distribution and adipose tissue hydration at 4.5 years | |
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, 7MRC Lifecourse Epidemiology Unit & NIHR Southampton Biomedical Research Centre, University of Southampton & University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom, 8Clinical Nutrition Research Centre, Singapore Institute for Clinical Sciences, A*STAR, Singapore, 9Department of Endocrinology, Tan Tock Seng Hospital, Singapore, 10Liggins Institute, University of Auckland, Auckland, New Zealand, 11Department of Diagnostic and Interventional Imaging, KK Women’s and Children’s Hospital, Singapore |
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The association of the duration of breastfeeding with childhood obesity is equivocal. The first year of life is a period of hypertrophic expansion of adipocytes with little increase in adipocyte number. Hence, over-nutrition during this period could potentially result in persistent changes in adipocyte size that may last until adulthood. In this study, we have investigated the association of breastfeeding duration with abdominal fat distribution and adipose tissue cellularity at 4.5 years. Our results indicate a weak protective effect of longer breastfeeding duration on abdominal subcutaneous adipose tissue volumes and subcutaneous adipose tissue morphology. |
| 2084 | Noninvasive Quantification of Prostate Cancer Using IVIM：evaluation of IVIM perfusion-related parameters by comparing to quantitative DCE-MRI | |
1Tianjin First Center Hospital, tianjin, People's Republic of China, 2Philips Healthcare, Beijing, People's Republic of China |
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The purpose of the study was to evaluate the clinical usefulness of IVIM technique for the PCa and furtherly investigate the diffusion and perfusion characteristics among PCa, normal peripheral zone (PZ) and central gland (CG) comparing to pharmacokinetic parameters based on quantitative DCE-MRI. The IVIM was performed at 11 b values of 0, 10, 20, 30, 50, 75, 100, 250, 500, 750 and 1000s/mm2. The
D value in prostate cancer were significantly lower than those
in the PZ and CG. The perfusion fractions in PCa were significantly higher than those in the PZ. There were no significant differences in the PCa, PZ and CG for the D*, which had large SDs. D showed significant negative correlations with Ktrans and Kep respectively, while f showed a significantly positive correlations with Ktrans and Kep. IVIM can provide more detailed information on perfusion and diffusion of prostate cancer noninvasively without intravenous contrast agent administration.
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| 2085 | Quantification of abdominal subcutaneous and visceral fat by magnetic resonance imaging of the proton at 3T: application to an overfeeding protocol. | |
1Univ. Lyon, INSA‐Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F69621, Lyon, France, 2Department of Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland, 3Centre de Recherche en Nutrition Humaine Rhône-Alpes (CRNH-RA), Centre Hospitalier Lyon Sud, Pierre-Bénite, Lyon, France, 4Hospices Civils de Lyon, Département d'imagerie digestive, CHU Edouard Herriot, Lyon, France |
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Overweight and obesity are a major worldwide health problem increasing the risk to develop pathologies such as diabetes and cardiovascular disease. The metabolic risk is modulated by the adiposity distribution and the fatty acid composition. Quantitative MRI to assess the fat volumes and composition is still little used. This study shows, using a single 3D multiple gradient echo sequence, that overfeeding has a significant effect on fat storage in the body with an increase of visceral and subcutaneous abdominal adipose tissues volumes, fat storage in the liver and seems to have an effect on stored fat composition. |
| 2086 | Magnetic Resonance Imaging Studies of a Testosterone and Estrogen-supplemented Experimental Mouse Model of Lower Urinary Tract Symptoms | |
1Radiology, The University of Chicago, Chicago, IL, United States, 2Surgery, The University of Chicago, Chicago, IL, United States |
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Lower urinary tract symptoms (LUTS) affect many elderly men and cause urinary obstruction and prostatic enlargement. The aim of this study was to use functional/anatomic MRI for serial imaging of LUTS development in a testosterone/estrogen-supplemented experimental mouse model. These mice exhibited a greater increase in prostate volume and decrease in urethra volume than control mice, and changes in urethral and prostatic volume were strongly inversely correlated. Results suggest that serial MRI could improve understanding of initiation and development of LUTS as well as the origin of clinical symptoms of benign prostatic hyperplasia, and evaluate effects of therapy in mouse models. |
| 2087 | Region-adaptive Deformable Registration for MRI/CT Pelvic Images via Bi-directional Image Synthesis | |
1School of Automation, Northwestern Polytechnical University, Xi'an, People's Republic of China, 2Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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Registering pelvic CT and MRI can help propagate accurate delineation of pelvic organs (prostate, bladder and rectum) from MRI to CT, since it is difficult to directly obtain accurate organ labels from CT due to its low soft-tissue contrast. We propose to use image synthesis to first eliminate the appearance gap between modalities by performing image synthesis in bi-directions in order to provide more anatomical information for guiding the registration. Then, a hierarchical region-adaptive registration framework is proposed to utilize the significant anatomical information from each modality to guide accurate MRI/CT deformable registration. |
| 2088 | On the influence of susceptibility-related field inhomogeneities caused by intestinal gases on the distortion in prostate and cervix | |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Medical Faculty, University Hospital Ulm, Ulm, Germany, 3Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 4Institute of Radiology, University Hospital Erlangen, Erlangen, Germany |
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Due to field inhomogeneities, MR-images suffer from image distortions in frequency-encoding direction. Using MRI as a tool for dose planning in MR-guided radiation therapy, image distortions play an important role in defining safety margins and the planning target volume (PTV). To investigate the influence of susceptibility-related field inhomogeneities on the distortion in prostate and cervix, distortions maps based on phase images were calculated for data acquired in a MR-guidance study. It was found that maximum distortions in prostate and rectum can be as large as 0.6 mm or 1.0 mm respectively, which should be considered when defining PTVs. |
| 2089 | The Value of Apparent Diffusion Coefficient Map based on PI-RADS v2 in Predicting Clinically Significant Prostate cancer | |
1Peking University First Hospital, Beijing, People's Republic of China |
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To determine the value of ADC map in identifying clinically significant prostate cancer, the ADC PI-RADS scores and mean ADC values of index lesion based on PI-RADS v2 were measured. ADC PI-RADS score may be good as overall PI-RADS v2 score in predicting clinically significant PCa. The clinically significant cancers had higher ADC scores and lower ADC values. An ADC value of 619-889×10-6 mm2/s may be useful in the identification of clinically significant cancers. |
| 2090 | The predictive value of preoperative examination in differenciating high and low Gleason score of radical prostatectomy specimens | |
1Peking University First Hospital, Beijing, People's Republic of China |
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To evaluate the value of different preoperative examniations in differenciating high/low Gleason score, prostate volumev(PV), PSA, PSA density (PSAD), DRE, multiparametric MRI (mpMRI) and transrectal ultrasound guided biopsy were analyzed. The area under curve (AUC) of PSAD was 0.911 with the cut-off level of 0.25, which was even better than biopsy(AUC=0.887). MpMRI performed good diagnostic accuracy according to PI-RADS v2 by Reader 1(AUC=0.831) and 2(AUC=0.933). |
| 2091 | Evaluation of Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) in predicting clinically significant prostate cancer: a whole-mount step-section analysis | |
1Peking University First Hospital, Beijing, People's Republic of China |
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The diagnostic accuracy of PI-RADS v2 for clinically significant cancer was evaluated by using whole-mount step-section slides as standard of reference. All significant cancers could be identified and the accuracy of PI-RADS 3 to 5 for predicting significant cancer was 91.7%, with high sensitivity (100%) and negative predictive value (100%). |
| 2092 | 3D T2-weighted fast spin echo (FSE) with outer volume suppression versus 2D FSE in the prostate: Comparison of lesion detection in the transition zone and image quality | |
1Radiology, Stanford University, Stanford, CA, United States, 2Global MR Applications and Workflow, GE Healthcare, 3Electrical Engineering and Radiology, Stanford University, Stanford, CA, United States |
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3D T2-weighted imaging (T2WI) of the prostate for prostate cancer (PCa) is often hampered by motion artifacts and signal starvation. However, incorporating reduced phase field of view capability using outer volume suppression (OVS) into 3D fast spin echo (FSE) can overcome these obstacles. In the prostatic transition zone (TZ), superior contrast and diminished blur were found over standard 2D FSE, with preserved SNR and anatomic detail. Diagnostic confidence was greater with 3D, whether used alone or in combination with 2D. Furthermore, less equivocal diagnoses resulted with the combination of 2D and 3D. |
| 2093 | Test-Retest Reliability of in bore MRI Guided Prostate Biopsy: a pilot study to optimize the current repeated biopsy paradigm in patients on Active Surveillance? | |
1Radiology, Emory University-School of Medicine, Atlanta, GA, United States, 2Urology, Emory University-School of Medicine, Atlanta, GA, United States, 3Pathology, Emory University-School of Medicine, Atlanta, GA, United States |
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Consistent results throughout repeated biopsy sessions is an essential requirement for any tool used for active surveillance. TRUS biopsy showed inconsistent results in repeated biopsy sessions. Regarding MRI guided biopsy, the reliability of repeated biopsies needs to be established. 5 patients with 17 lesions which were repeatedly biopsied under direct MRI guidance were included. Kappa statistics showed moderate agreement. Negative predictive value for 2nd biopsy was 93% and for 3rd biopsy was 90%. Consistent biopsy results may obviate the need for the current paradigm of obtaining annual prostate biopsies in patients undergoing active surveillance |
| 2094 | Computer-Aided Diagnosis of Prostate Cancer on Multiparametric MRI: the Application for Cancer Localization | |
1Peking University First Hospital, Beijing, People's Republic of China, 2Philips Healthcare, Suzhou, People's Republic of China |
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Multiparametric MRI (mpMRI), including T2WI, DWI/ADC and DCE, is becoming a promising noninvasive tool for prostate cancer (PCa) detection, localization and stage. Although PI-RADS has provides recommendations for image reading and reporting, the interpretation of mpMRI is still challenging for clinical work, for poor interobserver agreement and strong experience dependence. We therefore developed a machine learning model that combines features derived from mpMRI for PCa detection and localization. The model predicted the transition zone (TZ) and peripheral zones (PZ) separately and compared with whole-mount step-section slide. The computer-aided diagnosis (CAD) achieved excellent performance both in PZ and TZ. |
| 2095 | Can MR quantitative fat fraction technique evaluates bone marrow toxicity during radiotherapy and chemotherapy? | |
1Xijing Hospital, Xi 'an, People's Republic of China, 2GE Research China, GE Healthcare, People's Republic of China |
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Bone marrow toxicity is very common side effect during radio-chemotherapy treatment of pelvic tumors. In this study, six patients with cervical cancer were included. The Bone marrow fat faction of the subjects were evaluated using quantitative fat fraction MR technique before each week’s treatment and at the end of whole five weeks’ therapy. The results indicated that MRI was sensitive to marrow composition changes and can evaluate the real time bone marrow toxicity during radio-chemotherapy. This could potentially benefit patient with a more optimized treatment plan. |
| 2096 | Whole-Tumor Quantitative Apparent Diffusion Coefficient Histogram Analysis in Differentiating intrahepatic mass-forming cholangiocarcinoma from poorly differentiated hepatocellular carcinoma | |
1Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wu han, People's Republic of China |
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Differentiating intrahepatic mass-forming cholangiocarcinoma (IMCC) and poorly differentiated hepatocellular carcinoma(pHCC) is often difficult for radiologists, but it is important for providing appropriate treatments. In our study, we use noncontrast MRI with diffusion-weighted imaging in combination with whole-tumor quantitative apparent diffusion coefficient (ADC) histogram analysis to differentiate IMCC from pHCC. The result reveals that ADC histogram analysis based on the whole-tumor can be considered a useful and noninvasive method to help differentiate IMCC from pHCC. Especially ADC25% of histogram analysis allows differentiation of IMCC from pHCC with higher accuracy. |
| 2097 | Preoperative MRI of Uterine Malignant Mixed Mullerian Tumors versus Endometrial Carcinomas with Emphasis on Dynamic Enhancement Characteristics | |
1Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center at Houston, Houston, TX, United States, 2Diagnostic Radiology Department, MD Anderson Cancer Center, Houston, TX, United States, 3Biostatistics Department, MD Anderson Cancer Center, Houston, TX, United States, 4Department of Imaging Physics, MD Anderson Cancer Center, Houston, TX, United States |
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Distinguishing uterine malignant mixed mullerian tumors (MMMTs) from endometrial carcinomas preoperatively by pelvic MRI may help with surgical and treatment planning of this highly aggressive tumor. Our study found that prolapse of tumor through the external cervical os, delayed iso- or hyper-enhancement, high mean tumor: myometrium positive enhancement integral (PEI) ratio and low tumor signal enhancement ratio (SER) are more commonly seen in patients with MMMT and may alert the radiologist to the possibility of this diagnosis. |
| 2098 | Differentiation of Fat-Poor Renal Angiomyolipoma from Other Renal Tumors with Low Signal Intensities on T2-weighted MR Image | |
1Radiology, Anam Hospital, Korea University College of Medicine, Seoul, Korea, Republic of |
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A low T2 signal intensity is a well-known feature of fat-poor angiomyolipoma and papillary renal cell carcinoma. However, many other renal tumors showing low T2 signal intensity are encountered in daily practice. So, a low T2 signal intensity is not a pathognomonic finding for fat-poor angiomyolipoma and papillary RCC. Even though renal mass biopsy might be considered to establish a diagnosis for tumors without typical imaging features of renal cell carcinoma, the decision to biopsy or not sometimes seems to be difficult in small renal tumors. Accurate MR imaging characterization of renal masses is essential for ensuring appropriate management and avoiding unnecessary surgical procedure. |
| 2099 | Usefulness of Subtracted Images from 4 Minutes to 1 Minute in Dynamic Contrast-enhanced (DCE) Magnetic Resonance (MR) Imaging for Prostate Cancer; Pilot Study | |
1Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea, Republic of, 2Department of Biomedical Engineering, College of Electronic Information Engineering, Kyung Hee University, Korea, Republic of |
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The purpose of our study is to assess the usefulness of subtracted images from 4-1 min in DCE MR imaging for the prostate cancer diagnosis. Subtracted images from 4-1 min were assessed for the visual washout scores of prostate cancer and normal PZ, and compared with the time-contrast media curve patterns in each patient. A subtraction image set of DCE MRI 4-1 min mirrored time - concentration curve patterns of DCE MR imaging in prostate cancer and normal PZ. This subtraction image set can be a more simple method to display the DCE characteristics without any additional post-processing. |
| 2100 | Dynamic contrast-enhanced MRI for uterine cervical cancer: correlations with clinical staging and pathologic types | |
1Cancer Hospital, Chinese Academy of Medical Sciences, Beijing, People's Republic of China, 2GE Healthcare, MR Research China, Beijing |
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Tumor blood supply is closely related to the tumor occurrence, development, metastasis and prognosis. MRI is the optimal imaging method for investigating uterine cervical carcinoma, which provides excellent morphological information using conventional series. Additionally, the tumor perfusion information can be quantitatively assessed by dynamic contrast-enhanced MRI (DCE-MRI). DCE derived parameters include MaxSlop, CER, IAUGC, Ktrans, Kep and Ve. Our results showed mild negative correlation to clinical FIGO stage based on mean and maximum of Ktrans and Kep, increased minimum MaxSlop, and increased max- and mini-mum Ktrans in squamous cell carcinoma than those of adenocarcinoma. DCE-MRI is a significant supplement to provide valuable morphological information that contributes to clinical decision-making and prognosis prediction. |
| 2101 | Value of DWI and dynamic contrast-enhanced MRI in differentially diagnosing stage-Ⅰa endometrial carcinomas and endometrial polyps | |
1MRI Division, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China |
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Yuan Chen,female,graduated from Zhengzhou University,Master's degree in reading at the First Affiliated Hospital of Zhengzhou University. |
| 2102 | Conductivity imaging for assessing the treatment outcome of MR-HIFU ablation of uterine fibroids | |
1University Hospital Cologne, Cologne, Germany, 2Philips Research Europe, Hamburg, Germany, 3Samsung Medical Center, Seoul, Korea, Republic of |
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MR-HIFU is a non-invasive thermal therapy used to treat symptomatic uterine fibroids. During therapies, clinicians utilize information provided by MRI for treatment planning and to ensure ablation of fibroids using non-invasive temperature monitoring via PRFS thermometry. Thereafter, the therapeutic outcome is determined by measuring the non-perfused volume (NPV) following contrast agent administration. We present a case study using Electric Properties Tomography (EPT) for assessment of treatment outcome by correlating the change in conductivity to the NPV. An increase in conductivity of up to 20% was observed. Thus, EPT is a promising approach for assessment of treatment outcome. |
| 2103 | Benign prostatic hyperplasia after prostatic arterial embolization in a canine model: a 3T multi-parametric MR imaging and whole-mount step-section pathology correlated longitudinal study | |
1Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China, 2Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology |
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Prostatic arterial embolization (PAE) is a minimally invasive procedure developed in the recent years. Recent studies reported clinical applications of PAE in the treatment of BPH, and its safety and efficacy was confirmed. For the basic theory research, some scholars have made preliminary animal experiments in beagle dogs and pigs.To the best of our knowledge, there is no longitudinal study regarding BPH morphological and functional characteristics of BPH in different periods after PAE with multi-parametric magnetic resonance imaging (mp-MRI). |
| Exhibition Hall | Wednesday 8:15 - 10:15 |
| 2104 | Estimating breast tumor blood flow during neoadjuvant chemotherapy using interleaved high temporal and high spatial resolution MRI | |
1Division of Biomedical Imaging, University of Leeds, Leeds, United Kingdom, 2Department of Radiology, Leeds Teaching Hospital NHS Trust, 3Department of Medical Physics and Engineering, Leeds Teaching Hospital NHS Trust, 4Department of Western General Hospital, NHS Lothian |
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An ideal breast MRI protocol might include high spatial and high temporal resolution images acquired following a single contrast agent injection. Here we present an acquisition strategy to acquire both for clinical reporting and tracer kinetic analysis. The approach was evaluated using simulations and tested through application in patients undergoing neoadjuvant chemotherapy. Radiologists could adapt similar protocol strategies to examine the physiological characteristics of tumors and their associated changes during treatment without significantly compromising the data used for clinical reporting. |
| 2105 | Reducing computation time for registration in Breast DCE-MRI: Effects of percent sampling on kinetic analysis model parameters, uncertainties, and goodness of Fit | |
1Medical Biophysics, Western University, London, ON, Canada, 2Lawson Imaging, Lawson Health Research Institute, London, ON, Canada, 3Surgical Oncology, London Regional Cancer Program, London, ON, Canada, 4Oncology, Western University, London, ON, Canada, 5Radiation Oncology, London Regional Cancer Program, London, ON, Canada, 6Medical Imaging, Western University, London, ON, Canada, 7Diagnostic Imaging, St. Joseph's Health Center, London, ON, Canada, 8Physics and Engineering, London Regional Cancer Program, London, ON, Canada |
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Patient movement during dynamic contrast enhanced breast MRI acquisition can degrade signal enhancement curves. Non-rigid image registration can improve enhancement curves, but computation time can be long, especially if all voxels are sampled for cost function estimation. This work investigates the influence of the percentage of voxels sampled (PS) on goodness-of-fit, kinetic model parameter values and uncertainties. The spatial distribution of parameter values was more strongly influenced by registration and PS compared to global tumor measures. Registration with very low PS values increased parameter uncertainties compared to unregistered. 5 PS provided similar performance to 100 PS with reduced computation time. |
| 2106 | Detection and Morphology of Breast Lesions with Very Early Phase of Ultrafast Dynamic Contrast Enhanced MRI using Compressed Sensing Reconstruction | |
1Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan, 2Kyoto University Graduate School of Medicine, Kyoto, Japan, 3Division of Clinical Radiology Service, Kyoto University Hospital, Kyoto, Japan, 4MR Application Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany, 5Breast Surgery, Kyoto University, Kyoto, Japan |
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Using ultrafast DCE MRI (UF-DCE)with compressed sensing reconstruction, detection rate and morphology of breast lesions on very early phase images within 1 minutes post contrast injection were compared to those on full diagnostic protocol (FDP). Almost all (95%) of the lesions reported on FDP were identified on UF-DCE. Size of the lesions were slightly smaller on UF-DCE but within-2mm difference in 96% of masses. Considering that wash-in kinetic information can be obtained by UF-DCE, the current data of equivalent lesion detection, size and morphology evaluation on UF-DCE support its application to abbreviated breast MRI protocol. |
| 2107 | 10 Second Temporal Resolution of Early Enhancement Visualization: Framework for Fast Breast MRI Screening | |
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, 3Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI, United States, 4Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 5Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States, 6Department of Emergency Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States |
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In this work, we present a new methodology for an abbreviated dynamic contrast enhanced (DCE) MRI breast screening protocol. The methodology relays on a novel dynamic reconstruction scheme, local low-rank, applied to breast MR imaging for the first time. Our work provides the framework for a high resolution (0.83 mm isotropic), ultra-fast (10 second volumetric frame rate) imaging technology to deliver detailed information of the early enhancement phase of breast lesions, preserving diagnostic accuracy while shortening exam times. We demonstrate the feasibility of the proposed approach. |
| 2108 | 3D Volumetric Noncompressive Breast MR Elastography | |
1Radiology, Mayo Clinic, Rochester, MN, United States, 2Radiology, Mayo Clinic, Scottsdale, AZ, United States |
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Sternum drivers for breast MRE can produce shear waves in breasts without breast compression effect, which can result in increased breast stiffness due to tissue nonlinearity. A recent 5-slice 2D GREMRE sequence study found sternum driver MRE was a very reproducible method. In our current study, we were able to use 40-slice 3D GREMRE volumetric MRE sequence to compute volumetric breast elastograms in patients. |
| 2109 | T2* Mapping for Breast Tumor categorizing | |
1Clinical Science, Philips Healthcare, Beijing, People's Republic of China, 2Department of Radiology, Jiangxi Cancer Hospital |
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Utilizing the state of art water-fat separation method with multi-echo acquisition in mDIXON quant to explore the relationship between magnetic resonance transverse relaxation time (T2*) and the pathological type of breast tumors. |
| 2110 | MRI can assess breast cancer related lymphoedema tissue composition and guide management strategy | |
1CR-UK Cancer Imaging Centre, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, London, United Kingdom, 2Cardiac and Vascular Sciences, St. George’s University of London, London, United Kingdom, 3Skin Unit, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, London, United Kingdom |
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Here we present an MRI-based approach to assess breast cancer related lymphoedema tissue composition (fluid, fat, and muscle volumes) and we evaluate a cohort of 13 patients. Our measurements indicate that fat, which cannot be eliminated by first line treatment, was the predominant component of the swelling. Furthermore, changes in tissue composition were not uniform along the arm. Quantification of the volume and spatial distribution of different tissue components could greatly improve treatment delivery and patient selection for optimal treatment. With a 6 minute MRI scan and automated post-processing, this methodology shows potential for implementation in clinical practice. |
| 2111 | Accuracy of Multi-Expert algorithm for segmenting the breast | |
1Radiology Dept., NYU School of Medicine, New York, NY, United States |
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Breast density, defined as fraction of fibroglandular tissue (FGT), and post-contrast FGT enhancement (background parenchymal enhancement) are considered cancer risk factors. These MRI measures are recommended for radiologic reports and are promising cancer biomarkers. There is a general agreement that isolating the breasts from the chest wall (CW) is the most difficult to automate step in the FGT segmentation pipeline. Various methods for this task have been reported, but all show significant limitations. We have previously developed a semi-automated FGT segmentation tool that required approximately 7 min per case. We are reporting a new algorithm based on six overlapping Experts that significantly improves segmentation speed and accuracy. |
| 2112 | Quantifying Fibroglandular Tissue Volume using Chemical-Shift Encoded MRI: Validation in a Phantom | |
1Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 2Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States, 3Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 4Department of Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States, 5Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States, 6Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI, United States |
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Increased breast density is a known risk factor for the development of breast cancer. Quantitative MRI methods have the potential to provide accurate, volumetric measures of breast tissue volume and density. A novel, confounder-corrected chemical shift encoded (CSE) MRI technique designed to provide accurate fibroglandular tissue volume and density quantification is validated using a fat and water phantom. The CSE MRI technique provided accurate quantification of water and volumes and was robust to changes in spatial resolution and complexity of fat/water interfaces, indicating this method is expected to produce accurate and robust quantification of fibroglandular and adipose tissue in-vivo. |
| 2113 | T2 Relaxation Times of Breast Fibroglandular Tissue Measured From High Resolution, Non-Fat Saturated MR Imaging | |
1Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States |
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Reported T2 values in breast tissue are sparse and often disagree. In this study we estimate the T2 relaxation time of fibroglandular breast tissue including fatty compartments intermixed within the fibroglandular matrix. T2 mapping was performed at high spatial resolution for 15 patients at 3T with 4 TEs from 12 to 160 ms and intra- and inter-patient T2 heterogeneity were evaluated. T2 within the finroglandular environment is on the order of 100 ms with a mean standard deviation per patient of 29.6 ms. We hypothesize that this heterogeneity may reflect differences in the fibroglandular microenvironment related to breast cancer risk. |
| 2114 | Application of Whole-lesion Histogram Analysis of Pharmacokinetic Parameters in Dynamic Contrast-Enhanced MR Imaging of Breast lesions with CAIPIRINHA-Dixon-TWIST-VIBE Technique | |
1Radiology, Tongji Hospital, Wuhan, People's Republic of China, 2MR Collaboration NE Asia, Siemens Healthcare, 3MR Collaboration, Siemens Healthcare |
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As the use of neoadjuvant chemotherapy is gradually increased in the treatment of breast cancer, evaluating its therapeutic effect is gaining importance. However, tumors are markedly heterogeneous in cells, micro-environmental factors and vasculature structures, which manifests as radiologic heterogeneity. A few studies have been trying to extract heterogeneity metrics from regions of interest (ROIs) such as by means of histogram analysis. Thus, the aim of our study is to investigate the feasibility of whole-lesion histogram analysis of pharmacokinetic parameters in breast T1-weighted dynamic contrast-enhanced MR imaging (DCE-MRI) for differentiating the malignant from benign breast lesions. |
| 2115 | Comparison of methods for high spatial-resolution breast diffusion imaging | |
1Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States, 2Department of Radiology, University of Minnesota, Minneapolis, MN, United States |
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Diffusion weighted imaging (DWI) has applications in the screening, diagnosis, and treatment monitoring of breast cancer, but its clinical value in is limited by the low resolution and artifacts of standard methods. In this work we compared a standard method with two high-resolution techniques: read-out segmented EPI (RS-EPI) and single-shot simultaneous multi-slice EPI with in-plane slice encoding (SMS-IPSE). Both the SMS-IPSE and RS-EPI methods can produce high-resolution, accurate diffusion-weighted images at the cost of decreased SNR within a clinically practical 5-minute time window, enabling the detection of smaller lesions. |
| 2116 | Advanced Ultrafast Dynamic Contrast Enhanced Breast MRI with Compressed Sensing VIBE | |
1Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, Netherlands, 2MR-Application Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany |
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Previous work showed that ultrafast breast DCE-MRI enables assessment of the contrast inflow curve while providing images at diagnostic spatial resolution. However, the slice thickness (~2.5mm) prevented multiplanar reconstructions and therefore did not yield the same morphological information as obtained with conventional T1-weighted series. We evaluate a compressed sensing VIBE sequence (CS-VIBE) for ultrafast breast MRI that enables high spatio-temporal resolution for both dynamic inflow analysis and morphological evaluation. Two reader-studies were conducted to evaluate image quality and lesion morphology assessment. Our results show that CS-VIBE combines the advantages of both high-spatial and high-temporal resolution of clinically available sequences. |
| 2117 | Dynamic contrast-enhanced magnetic resonance imaging in discriminating invasive ductal carcinoma and fibroadenoma: 2D maximum diameter versus 3D whole-tumor | |
1Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, Shaanxi, People's Republic of China |
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DCE quantitative measurement plays an important role in the identification of breast tumors. However, different ROI placement can directly affect the inspection results. However, there is no clear standard protocol for clinical routine use. This study aims to evaluate the effect of 2-dimensional maximum diameter (2DMD) and 3-dimensional whole-tumor (3DWT) on quantitative DCE-MRI in differentiating invasive ductal carcinoma (IDC) and breast fibroadenoma which are confirmed by surgical pathology, and determined the more efficient approach for ROI measurement. Our results suggested that 2DMD mean value has more diagnostic performance than 3DWT assessment in distinguishing IDC from fibroadenoma. |
| 2118 | Comparison of whole tumor and single slice ROIs for measuring ADC in breast cancer | |
1University of California, San Francisco, CA, United States |
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Diffusion weighted imaging is a promising technique to monitor treatment response in patients undergoing pre-surgical chemotherapy, but manually drawn whole tumor measurements are time-consuming and subject to inter-user variability. In this study of 60 patients with sequential DWI exams during treatment, we measured apparent diffusion coefficient (ADC) from whole tumor ROIs and from a single central slice of the tumor. We found strong agreement in ADC between the two methods, suggesting that a slice from the center of the tumor may accurately represent the ADC of the entire tumor. |
| 2119 | Abbreviated Breast Magnetic Resonance Imaging (MRI) for Extent of Disease Evaluation in Newly Diagnosed Breast Cancer | |
1Radiology, UCLA, Los Angeles, CA, United States, 2UCLA |
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In this retrospective study, an abbreviated protocol consisting of pre-contrast T1 and first post-contrast T1 sequences with fat saturation had near perfect detection of index and secondary cancers, as well as suspicious axillary and internal mammary lymph nodes, in women with newly diagnosed breast cancer. In conjunction with clinical histories and prior imaging examinations, an abbreviated breast MRI protocol is adequate for ipsilateral extent of disease and contralateral breast screening in newly diagnosed breast cancer. |
| 2120 | Dynamic Contrast-Enhanced Breast MRI using A Chemically Fat-Suppressed View-Sharing Technique | |
1Global MR Applications & Workflow, GE Healthcare, Madison, WI, United States, 2Global MR Applications & Workflow, GE Healthcare, Hino, Japan, 3Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 4Radiology, University of Wisconsin-Madison, Madison, WI, United States, 5Global MR Applications & Workflow, GE Healthcare, Houston, TX, United States, 6Carbone Cancer Center, University of Wisconsin-Madison, Madison, WI, United States |
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In clinical breast MRI, the dynamic contrast-enhanced (DCE) T1-weighted fat-suppressed scan plays an essential role for lesion detection and characterization. In order to improve temporal resolution of the dynamic scan, view-sharing techniques are typically used along with Dixon-based water-fat separation methods. However, there are several limitations and drawbacks of using Dixon-based techniques. In this work, we proposed to use chemical fat suppression with view-sharing to improve the temporal resolution of DCE breast MRI. |
| 2121 | Image quality of silicone-specific STIR Cube-FLEX MRI for breast implant imaging | |
1Radiology, Stanford University School of Medicine, Stanford, CA, United States, 2Radiology, Rakuwakai Otowa Hospital, Kyoto, Japan, 3GE Medical Systems |
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3D Fast-Spin-Echo MRI with Short Tau inversion recovery fat suppression and 2-point Dixon decomposition of water and silicone signal (STIR Cube-FLEX or “Si-Cube”) is a recently developed silicone-specific sequence providing isotropic, high-resolution 3D datasets that are easily reformatted into any plane. We performed a reader study to evaluate the image quality of Si-Cube in 39 females, and found Si-Cube is robust to artifacts and has equivalent image quality to conventional 2D silicone-specific sequences (C-2D). The ability to reformat Si-Cube images in any plane potentially obviates the need to obtain C-2D sequences in other planes, streamlining the overall implant imaging protocol. |
| 2122 | Comparing the diagnosis efficiency of different parameters of diffusion kurtosis imaging model in benign and malignant breast lesions | |
1The First Affiliated Hospital of Zhengzhou University, zheng zhou, People's Republic of China, 2GE Healthcare,MR Research China, People's Republic of China |
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In order to comparethe diagnosis efficiency of different parameters derived from diffusion kurtosis imaging model in benign and malignant breast lesions, eighty patients were analyzed in this study . DKI data with six b-values and 15 directions were acquired using single-shot SE-EPI sequence. The values of mean kurtosis (MK), axial kurtosis (AK) and radial kurtosis（RK） in malignant lesions group were significantly higher than those in benign lesions groups. The diagnosis efficiency of these parameters were also analyzed. The results showed that DKI-derived parameters can be used to distinguish the malignant lesions and benign lesions, especially AK and MK |
| 2123 | Ductal carcinoma in situ of the breast: Investigation of quantitative MRI features of lesion and normal tissue to predict recurrence after treatment | |
1Radiology, University of Washington, Seattle, WA, United States, 2Breast Imaging, Seattle Cancer Care Alliance, Seattle, WA, United States |
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Ductal carcinoma in situ (DCIS) is a pre-invasive breast cancer that may be overtreated due to lack of reliable clinical and pathological prognostic features. Kinetics parameters on dynamic contrast-enhanced MRI have shown promise as breast cancer risk biomarkers. We compared imaging parameters of lesions and normal breast tissue between patients with DCIS recurrence and matched controls and found that patients with larger lesions with higher signal enhancement ratio (SER) and higher background parenchymal enhancement (BPE) on preoperative MRI were more likely to recur. These MRI biomarkers show promise for decreasing DCIS overtreatment and warrant further study in larger cohorts. |
| 2124 | Breast Background Parenchymal Enhancement as a Marker of Breast Cancer Recurrence Risk | |
1Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, 2Department of Medicine, Massachusetts General Hospital, Boston, MA, United States |
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Emerging studies suggest that imaging features could complement standard pathologic variables in cancer prognostic assessment. Studies on the association of background parenchymal enhancement (BPE) with breast cancer prognosis remain limited. The goal of this study was to investigate the complementary value of breast BPE as a prognostic marker for breast cancer recurrence risk assessment. DCE-MRI images were retrospectively analyzed from 100 women with breast cancer. Oncotype DX score was used as a surrogate for cancer recurrence. Our results suggest that BPE could complement histopathologic factors in predicting breast cancer recurrence risk and could potentially improve breast cancer prognostication. |
| 2125 | Perfusion Parameters at Dynamic Contrast-enhanced Breast MR Imaging are Associated with Disease-Specific Survival in Patients with Triple-Negative Breast Cancer | |
1Radiology, Yonsei University College of Medicine, Seoul, Korea, Republic of |
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We investigated the association between perfusion parameters in pretreatment MR imaging and survival outcome. This retrospective study included 61 consecutive patients (median age, 50 years; range, 27-77 years) diagnosed with TNBC who underwent pretreatment DCE breast MR imaging and definitive surgery. The median follow-up time was 46.1 months. Among pretreatment variables, a higher ve value and higher peak enhancement at pretreatment MR imaging were significantly associated with worse disease-specific survival in patients with TNBC. With further validation, these perfusion parameters have the potential to aid in the pretreatment risk stratification of patients with TNBC and in evidence-based clinical decision support. |
| 2126 | Quantitative Breast MRI Background Parenchymal Enhancement for Predicting Response to Chemotherapy | |
1University of California, San Francisco, San Francisco, CA, United States, 2University of California, San Francisco |
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The purpose of this study was to investigate how background parenchymal enhancement (BPE) may additively improve an MR tumor model for prediction of non-pathologic complete response (non-PCR) patients in the neoadjuvant setting. BPE identified 24-36% of non-PCR patients independent of tumor factors while maintaining a low misclassification of PCR patients. In conjunction with a tumor model using tumor and treatment factors, addition of BPE may improve residual cancer prediction of up to 60% of patients, but results were not statistically significant. |
| 2127 | The Significance of Joint Clinical Application of Digital Mammary Gland 3D Tomosynthesis with Magnetic Resonance Imaging for Diagnosis of Breast Cancer | |
1National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China, 2GE HealthCare, MR Research China, Beijing, People's Republic of China |
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Synopsis In recent years, the incidence rate of breast cancer in China has been rising rapidly, which highlights the importance of early diagnosis. Therefore, how to improve the detection rate and reduce the recall rate become significant for the breast cancer prevention and treatment. Considering the tissue overlapping effect from conventional digital mammary gland photography technology may lead to false positive and negative results. |
| 2128 | Multicenter study of intravoxel incoherent motion (IVIM) metrics in breast cancer with software comparison. | |
1Radiology, Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, New York, NY, United States, 2Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States, 3Radiology, Center for Advanced Imaging Innovation and Research (CAI2R), New York University Langone Medical Center, New York, NY, United States |
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This study compares data collected from different MR vendor systems using different software packages to better understand the robustness and reproducibility of IVIM metrics. Patient data from 2 sites (Site 1 & 2) from 1.5/3T systems (GE/Siemens) were analyzed with 2 software packages to derive IVIM biomarkers and their intersite/software variability. Results show that metrics of IVIM average and histogram analysis are robust quantitative imaging biomarkers for breast cancer. |
| 2129 | Using Natural Language Processing to Explore the Correlation of Breast MR Findings and BI-RADS classification | |
1Radiology, Peking University First Hospital, Beijing, People's Republic of China, 2Philips Research China, Shanghai, People's Republic of China |
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The decision tree trained on MR descriptions by natural language processing (NLP) method shows desirable capability in identifying the high-risk BI-RADS 5-6 class.From the decision path, we identify the key indicators to distinguish BI-RADS 5-6 from the relatively low-risk classes. And the inner heterogeneity of BI-RADS 4 cases makes it difficult to build a general model for this class. |
| 2130 | Quantitative analysis of background parenchymal enhancement in whole breast on MRI: influence of menstrual cycle and comparison with qualitative analysis | |
1Radiology, Ajou University Hospital, Suwon, Korea, Republic of |
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We quantitatively analyzed the background parenchymal enhancement of whole breast on MRI using in-house software with MATLAB. The mean values of BPE were well correlated with qualitative grades of BPE. The mean and ninety percentile values of BPE were lowest in 2nd week of menstrual cycle and highest in 4th week with statistical significance (p=0.005 for mean values and p=0.003 for nienty percentile, respectively). |
| 2131 | Gradient tracing for segmentation of low resolution, low T1-weighted breast MR images | |
1Radiology, UW- Madison, Madison, WI, United States, 2Biostatistics and Medical Informatics, UW- Madison, WI, United States, 3Medical Physics, UW- Madison, Madison, WI, United States, 4Medicine, UW- Madison, Madison, WI, United States, 5Biomedical Engineering, UW- Madison, Madison, WI, United States, 6Emergency Medicine, UW- Madison, Madison, WI, United States, 7Carbone Cancer Center, UW- Madison, Madison, WI, United States |
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Segmentation of breast MR images remains a challenge and a necessity for a variety of quantitative applications. We present a semi-automatic methodology for segmentation of breast tissue for the special case of low resolution, low flip angle chemical shift encoded MRI (CSE-MRI) with water-fat separation. User interaction is required to set the bounds of the segmentation, while the chest wall and skin are segmented automatically. The results differed with corrections by an experienced radiologist by 4.2% average error per case. The method exhibits comparable accuracy to published methods and high agreement between non-expert reviewers. |
| 2132 | Sub-millimeter bSSFP isotropic T2 weighted breast imaging - results of a prospective clinical study to determine if specificity of breast MRI can be improved. | |
1Radiology, University of Wisconsin, Madison, WI, United States, 2Medical Physics, University of Wisconsin, WI, United States |
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Although DCE-MRI is the mainstay of breast MRI diagnosis, specificity is limited due to multiple enhancing benign lesions. Specificity can by improved by viewing T2 information, but conventional T2 imaging is limited by spatial resolution. We performed a prospective clinical study of a novel T2-like imaging sequence with sub-mm spatial resolution to determine if a breast radiologist could improve his assessment of benignity. Results show that excellent spatial resolution was achieved, but at the cost of increased noise and loss of T2 contrast. Ultimately, the radiologist felt less confident in more cases than he felt more confident regarding benign lesions. |
| 2133 | Association of Preoperative MR Imaging Features with Positive Resection Margins in Breast Conservation Surgery | |
1Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States |
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Breast conservation surgery (BCS) is a standard treatment for early-stage breast cancer, and includes a complete removal of the tumor with a margin of tumor-free breast tissue. If margins of the resected tissue are involved at final surgical pathology, patients undergo additional surgery. Although MR imaging is the most sensitive modality for breast cancer, the effect of preoperative MR imaging on the improvement of surgical outcomes is controversial. There are only a few studies evaluating association between preoperative MR imaging features and positive resection margins (RMs) in patients with invasive breast cancer. |
| 2134 | Quantitative assessement of MRI Background Parenchymal Enhancement in comparison with qualitative assessment – Can it predict breast cancer? | |
1Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria |
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While breast density is a recognized risk factor for breast cancer, the role of background parenchymal enhancement (BPE) is still controversially discussed. Since BPE reflects hormonally active breast tissue, it may serve as a biomarker for malignancy. Current assessment of BPE, however, is hampered by the subjective nature of its assessment. We therefore tested an automated approach that quantified the percentage of enhancing breast tissue of the entire contralateral breast. This pilot study finds the amount of quantitatively assessed enhanced breast parenchyma as a percentage of the entire breast to inversely correlate with breast cancer risk, while visually estimated BPE did not correlate with breast cancer. |
| 2135 | Is ADC heterogeneity helpful in characterizing ductal carcinoma in situ (DCIS) at 3.0T breast MRI | |
1Medical Physics and Research Department, Hong Kong Sanatorium & Hosptial, Hong Kong, Hong Kong, 2Department of Diagnostic & Interventional Radiology, Hong Kong Sanatorium & Hosptial, Hong Kong, Hong Kong, 3Breast Care Center, Hong Kong Sanatorium & Hosptial, Hong Kong, Hong Kong |
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In this study, we intended to investigate the relationship between ADC heterogeneity of DCIS lesions and DCIS lesioxn morphology, histological grade and BIRADS classification using 3T DW breast MRI. Increasing heterogeneity was observed with increasing DCIS histological grade and increasing BIRADS, but not reaching significance level, was observed based on our results. This study was mainly limited in the small numbers of DCIS lesions, so statistical power has to be further strengthened in future studies with larger sample size. |
| Exhibition Hall | Wednesday 8:15 - 10:15 |
| 2136 | Utility of MRI for the Evaluation of Acute Pulmonary Embolism | |
1Medical Imaging, Banner University Medical Center, Tucson, AZ, United States |
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CT-PA is the gold standard for diagnosis of pulmonary embolism, but requires use of radiation and iodinated contrast. There is an overall low incidence of positive studies (5%) in the patient population 18-45. Our study evaluates the negative predictive value of MRI as the primary imaging modality for exclusion of suspected PE in patients <40 y/o and/or relative contraindication to iodinated contrast. We found a negative predictive value of 99% in our patient population. These results suggest that MRI is an effective first-line imaging modality to exclude PE, while reducing exposure to ionizing radiation and iodinated contrast. |
| 2137 | Evaluation of ventilation changes in lung transplant recipients with hyperpolarized helium-3 MR imaging: Comparison with pulmonary function tests | |
1Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States, 2Department of Radiology, University of Missouri, 3Pulmonary and Critical Care Medicine, University of Virginia |
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Purpose: To determine if the changes in lung ventilation using HP 3He-MRI can provide in vivo pulmonary physiology highly relevant in defining CLAD phenotypes among lung transplant patients, phenotypes which otherwise are undetectable by the usual PFT parameters such as FEV1. Methods: Thirteen lung transplant recipients underwent ventilation HP 3He MR lung imaging and spirometry; the latter was compared to baseline spirometry. Time from transplant was 2.5 ±2.5 yrs. Results/ Conclusion: Declined lung function after lung transplant correlated well with decreased ventilated lung volume in the transplanted lung found with HP 3He MRI. |
| 2138 | 3D Mapping of Whole Lung Morphometry with 129Xe Diffusion-Weighted MRI and Compressed Sensing: Comparison with 3He | |
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom, 2Department of Bioengeering, Universidad Carlos III de Madrid, Madrid, Spain |
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3D whole lung morphometry maps were acquired with 129Xe DW-MRI and compressed sensing. Prospective three-fold undersampled 3D 129Xe lung morphometry (LmD) maps were derived using the stretched exponential model (SEM) and compared with equivalent 3He datasets. Five healthy volunteers were imaged using a range of 129Xe diffusion times and the most agreeable 129Xe and 3He LmD results were obtained with a 129Xe diffusion time of 8.5 ms. These results indicate that the LmD values derived from the SEM are dependent on diffusion time and that 129Xe could present a clinically-viable alternative to 3He for whole lung morphometry mapping. |
| 2139 | Rapid acquisition of co-registered 3D xenon-129 and proton images of the human lung in a single breath-hold using compressed sensing | |
1Academic Unit of Radiology, University of sheffield, Sheffield, United Kingdom |
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The feasibility and suitability of using compressed sensing to accelerate the acquisition of 3D lung ventilation images with hyperpolarized 129Xe and to enable same-breath anatomical 1H imaging was investigated. Fully sampled and prospective data were acquired from one healthy smoker. Retrospective simulations showed a good agreement between fully sampled and reconstructed images using different error metrics. The method was further validated by comparing quantitative imaging metrics; percentage ventilated volume, distribution of signal intensity and maps of coefficient of variation in prospectively acquired data. The results indicate that the method can be implemented for clinical evaluation in patients with lung diseases. |
| 2140 | Large-scale production of highly-polarized 129Xe | |
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom |
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Rapid production of large volumes of highly polarized 129Xe with continuous-flow spin-exchange optical pumping (SEOP) 129Xe polarizers is vital for high-throughput hyperpolarized (HP) 129Xe lung imaging and emergent clinical applications with dissolved 129Xe, e.g. brain perfusion. However, the production rate is limited by cell volume, previously between 300-1500 cm3. Here we present a custom-built 129Xe polarizer designed with a SEOP cell volume of 3500 cm3 which can produce 129Xe polarized to 35% at a Xe production rate of 1200 mL/hour, enabling high-SNR 129Xe lung imaging of naturally abundant Xe and high-SNR 129Xe brain imaging with isotopically-enriched Xe. |
| 2141 | Double tracer gas single breath washout (SBW) lung imaging with hyperpolarized Xe-129 and He-3 | |
1Academic Radiology, University of Sheffield, Sheffield, United Kingdom, 2Insigneo Institute, University of Sheffield, Sheffield, United Kingdom |
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Single breath washout (SBW) is an emerging pulmonary function test due to its relative simplicity and speed. Most significant outcome parameter, phase III ‘alveolar’ slope (tracer gas decay during mid-exhalation) is sensitive to ventilation heterogeneity. In this work, a method is presented for SBW-imaging with two tracer gases with inherently different physical properties: hyperpolarized 129Xe and 3He. Findings in our study are in agreement with trends seen in SBW from pulmonary function lab: the heavier, less diffusive gas (129Xe) has a steeper phase III slope. This indicates increased regional ventilation heterogeneity due to a lesser degree of diffusional mixing. |
| 2142 | Assessment of Repeatability of Disease Burden and ADC estimates in Malignant Pleural Mesothelioma using Diffusion Weighted Imaging | |
1Division of Radiotherapy and Imaging, Cancer Research UK Cancer Imaging Centre, Institute of Cancer Research, London, United Kingdom, 2Radiology, Royal Marsden Hospital, London, United Kingdom |
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We demonstrate the repeatability of tumour volume and apparent diffusion coefficient (ADC) estimates; obtained by combining 3D semi-automatic segmentation with a global ADC threshold using DW-MRI in malignant pleural mesothelioma. The results of our classification of solid tumour show excellent repeatability of mean and median ADC estimates and tumour volume. Our methodology provides a clinical tool for radiologists to evaluate tumour burden of MPM in a fast and highly repeatable way. |
| 2143 | Dissolved phase Hyperpolarized Xenon-129 pulmonary imaging in the presence of gaseous Xenon signal | |
1Department of Medical Physics, University of Wisconsin at Madison, Madison, WI, United States, 2Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, NC, United States |
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Dissolved-phase hyperpolarized Xenon-129 imaging shows promise as a means to evaluate gas transfer from the airspaces of the lungs to parenchymal tissue and the blood stream. This typically requires selective excitation of dissolved-phase 129Xe, but its short T2* requires the use of short RF pulses. This reduces the achievable spectral selectivity and often leads to unwanted excitation of gas-phase Xenon. In this work, we present a method to selectively remove gas-phase contamination from dissolved-phase images. Our method is developed and validated with guidance from simulated data using a digital phantom and shown to be feasible in human subject scans. |
| 2144 | Optimizing data efficiency in SENCEFUL-based lung perfusion studies | |
1Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany |
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SElf-gated Non-Contrast-Enhanced FUnctional Lung imaging (SENCEFUL) allows assessment of lung ventilation and perfusion without the use of contrast agent or ionizing radiation. The original implementation, however, is rather inefficient in terms of data usage when reconstructing perfusion weighted datasets, as it analyzes data from a single breathing state only. In this study we present an approach that uses data from all breathing states, aiming at an improved quality of the resulting perfusion maps. A registration algorithm was applied for this purpose. |
| 2145 | Assessment of lung inflation state on the repeatability of hyperpolarized gas ventilation MRI | |
1POLARIS, Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom, 2Sheffield Childrens Hospital, Sheffield, United Kingdom, 3Insigneo Institute for in silico Medicine, Sheffield, United Kingdom |
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Repeatability of inflation levels, and the imaging metrics derived from them, is important in hyperpolarized gas MRI, particularly when attempting to measure a response from interventions. This work presents same-session repeatability of 5 different inflation levels and their accuracy in comparison to plethysmography measures. Further the effect of inflation level on percent ventilated lung volume and coefficient of variation was investigated. The most repeatable lung volumes were total lung capacity, functional residual capacity plus 1 liter and residual volume. Percent ventilated lung volume was repeatable to within a maximum of 2% error. |
| 2146 | Optimization of free breathing radial DCE-MRI protocol for quantitative clinical evaluation of pleural malignancies | |
1Radiology, Brigham and Women's Hospital, Boston, MA, United States, 2Siemens Healthcare USA |
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Clinical diagnosis of pleural malignancies and evaluation of their treatment response to novel anti-angiogenic agents would benefit from quantitative clinical DCE-MRI. Implementation of robust DCE-MRI of the thorax is challenging given the presence of significant respiratory motion. We optimized a clinical DCE-MRI protocol based upon the Radial Stack of Stars acquisition scheme to obtain 3-dimensional motion insensitive DCE-MRI of pleural malignancies. When compared to other commonly used DCE-MRI protocols with cartisian acquisitions, our free breathing protocol demonstrated good SNR, minimal motion down to a spatial resolution of 2mm3. |
| 2147 | 3D UTE Cones for high resolution MR lung imaging and lung density visualisation | |
1Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland, 2Information Technology and Electrical Engineering, ETH, Zürich, Switzerland, 3GE Global Research, Munich, Germany, 4GE Healthcare, Waukesha, WI, United States |
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The primary objective of this study is to test 3D UTE Cones clinically for MR lung imaging. The purpose of the investigation is twofold. Primary goal is to test whether or not Cones can be used for high resolution lung anatomical imaging that might be useful for imaging vessels or pulmonary nodules. We test also the possibility for detecting and visualising the lung density that can also be used for imaging parenchyma diseases and more importantly can lead to more accurate extraction of lung attenuation maps for PET/MR attenuation correction. |
| 2148 | Reproducibility and Methodological Considerations for Dissolved-Phase 129Xe Spectroscopy in Patients with Idiopathic Pulmonary Fibrosis. | |
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom, 2Academic Directorate of Respiratory Medicine, Sheffield Teaching Hospitals, Sheffield, United Kingdom, 3Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom |
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The reproducibility of quantitative parameters of pulmonary gas-exchange function derived from 129Xe chemical shift saturation recovery (CSSR) and high-resolution spectroscopy (HRS) was evaluated in patients with idiopathic pulmonary fibrosis. Of the CSSR-derived parameters, surface-area-to-volume ratio was found to be most reproducible (intraclass correlation κ=0.756). Furthermore, the ratio of 129Xe signal in pulmonary red blood cells (RBC) to tissue/plasma (TP) from HRS exhibited good reproducibility (κ=0.760). The clinical interpretation of these results is discussed along with methodological considerations and their bearing on the future clinical potential of these techniques. |
| 2149 | Implications of B0 and B1 inhomogeneity for bSSFP imaging of hyperpolarized media | |
1University of Sheffield, Sheffield, United Kingdom |
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The effect of B0 and B1 transmit inhomogeneity on 3D bSSFP lung imaging with hyperpolarized 129Xe was simulated using flip angle and off-resonance frequency maps in combination with the matrix product operator approach to predict 129Xe magnetization dynamics and associated bSSFP signal distributions. B1-related signal drop-off was predicted in posterior and some anterior regions, whilst central regions were generally robust to flip angle variations. Regions of high off-resonance frequency near the diaphragm resulted in low simulated bSSFP signal, corresponding spatially to banding artifact locations. When combined, the two factors led to mean bSSFP image intensity variations ~15-20%. |
| 2150 | Comparison of quantitative algorithms for calculating VDP from hyperpolarized 129Xe MRI – testing reproducibility of a biomarker of airway obstruction | |
1Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 2Department of Electrical and Computer Engineering, Duke University, NC, United States, 3Department of Biomedical Engineering, Duke University, NC, United States, 4Department of Medical Physics, Duke University, NC, United States, 5Department of Radiology, Duke University, NC, United States, 6Center for In Vivo Microscopy, Duke University, NC, United States, 7Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, 8Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States |
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There is a need to establish robust quantification pipelines to analyze 129Xe ventilation MRI for multi-center studies. Moreover, there is increasing interest in quantifying not only ventilation defect percent, but also regions of low and high ventilation. To this end, we sought to determine inter-method agreement between two different semi-automated quantitative mapping approaches — linear binning and adaptive K-means. The results suggest that once bias field corrections are applied consistently, both ventilation analysis methods agree well when classifying ventilation into 4 bins. Thus, with key steps outlined here, either method can be readily deployed in multi-center studies. |
| 2151 | Density-adapted UTE for SF6 visualisation in small animal lung imaging | |
1Core Facility Small Animal MRI, Ulm University, Ulm, Germany, 2Department of Diagnostic and Interventional Radiology, University Medical Center Ulm, Ulm, Germany, 3Institute of Radiology, University Hospital Erlangen, Erlangen, Germany, 4Internal Medicine II, University Hospital of Ulm, Ulm, Germany |
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Fluorinated gases as hexafluorane (SF6) may be used to visualize ventilations in lungs clinical and preclinical acquisitions. SF6 is characterized by T1 ~ T2* ~ 1 ms, therefore is best visualized with sequences allowing for short TR and TE, such as 3D UTE. SNR is generally limited by low spin density and low thermal polarization. In this work, we applied a density-adapted sampling scheme, previously developed for 23Na imaging, to the visualization of SF6 in phantom and in-vivo lung mice acquisitions. We verified that it increases image SNR and sharpness with respect to regular sampling without significant drawbacks. |
| 2152 | Quantifying Changes in Time-Resolved Hyperpolarized 129Xe Spectroscopy among Healthy and IPF Subjects | |
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 Electrical and Computer Engineering, Duke University, Durham, United States, 5Division of Pulmonary, Allergy and Critical Care, Department of Medicine, Duke University Medical Center, Durham, NC, United States, 6Department of Radiology, Duke University Medical Center, Durham, NC, United States |
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The spectral parameters of 129Xe in airspaces, interstitium and red blood cells (RBCs) are sensitive to disease. We sought to test how these parameters change during inhalation, breath-hold, and exhalation, and identify dynamic signatures that distinguish healthy subjects from patients with idiopathic pulmonary fibrosis (IPF). We find in all subjects that the RBC amplitude oscillates at the cardiac pulsation frequency. However, in IPF patients, this oscillation is also prominent in the chemical shift and phase of the RBC resonance. These dynamic metrics are potentially useful biomarkers for disease progression, as well as discriminating between different pathologies that impact gas exchange. |
| 2153 | Continuous Cryogen-Free Up-Concentration of Hyperpolarized $$$^{129}$$$Xe Gas | |
1Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany, 2Helmholtz-Zentrum Geesthacht, Geesthacht, Germany |
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A semipermeable membrane was utilized to separate the process gas helium from a continuous gas stream containing hyperpolarized $$$^{129}$$$Xe. By this the xenon partial pressure was increased by a factor of ten and the gross amount of helium was removed from the gas stream which was fed from the polarizer to a liquid probe within an NMR spectrometer. Using a sample of dissolved cryptophane-A cage allowed to separate the effects of up-concentration and polarization loss. The increase in xenon partial pressure was still a twofold higher than the polarization loss we have seen and improvements are obvious from the analysis. |
| 2154 | Diaphragm displacement during ABC controlled breath holding: is there an optimal inspiratory threshold? | |
1University Hospitals of Leicester NHS Trust, Leicester, United Kingdom, 2CRUK Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, London, United Kingdom |
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Diaphragm motion range during controlled breath-holding at three different inspiratory levels was assessed during dynamic MRI employing an Active Breathing Coordinator (ABC). Colour intensity projections displayed diaphragm position with time. Diaphragm displacements were calculated from difference images between the end and beginning of breath-holds. Overall, diaphragm volume displacements were smaller for the 75% deep inhalational volume (DIV) threshold typically applied in lung and breast radiotherapy, than for the shallower inspiratory levels of 50% and 25% DIV. The clinical standard 75% DIV threshold not only expands the lungs more but also decreases diaphragm motion range. |
| 2155 | Evaluation of the impact of blood inflow on free-breathing 2D dynamic oxygen-enhanced MRI | |
1Bioxydyn Ltd, Manchester, United Kingdom, 2School of Health Sciences, The University of Manchester, Manchester, United Kingdom |
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Technical validation of dynamic oxygen–enhanced MRI (OE-MRI) techniques is required for them to become accepted and useful imaging biomarkers. In this work we quantify the impact of using different scanner platforms and protocols on the parameterisation of dynamic single-slice OE-MRI of the lung. Results show that blood in-flow effects consistently provided lower estimates of baseline T1 and higher estimates of maximum change in partial pressure of oxygen, but it does not influence the wash in time estimation. This suggests that sensitivity to variation in ventilation is approximately equivalent using both protocols. |
| 2156 | Point-resolved spectroscopy with self-navigation for precise reversible transverse relaxation quantification in pulmonary tissue robust to breathing state variation at 1.5 and 3 Tesla | |
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, 2Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States, 3Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States |
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The reversible transverse relaxation time is currently under investigation as a promising biomarker for diagnosis of lung diseases. We propose an enhanced point-resolved spectroscopy sequence for precise relaxation quantification with self-navigation robust to breathing state variation. The obtained relaxation times show evidence for sensitivity to tissue structure alteration during normal breathing. This approach potentially enables a precise assessment of tissue structure in pulmonary diseases such as fibrosis and COPD. |
| 2157 | Fast Dynamic Lung Ventilation MRI of Hyperpolarized 129-Xenon using Spiral k-space Sampling | |
1Department of Oncology, University Of Oxford, OXFORD, United Kingdom, 2Department of Radiology, The Churchill Hospital, OXFORD, United Kingdom, 3General Electric Global Research, Munich, Germany |
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We implemented a spiral k-space sampling approach for Dynamic hyperpolarized 129Xe Ventilation Imaging (DXeVI) of human lungs. The gas-inflow effect, susceptibility artifacts, spatial and temporal resolutions for capturing Gas Flow Patterns (GFPs) were quantified in the gas-flow phantom and compared to corresponding simulated GFPs. DXeVI of GFPs are shown to be sensitive to small gas flow changes between the anterior and posterior lung regions in healthy three subject. This technique can potentially be used to detect and quantify ventilation defects associated with early stage COPD or asthma to assess disease severity, response to treatments and to identify disease progression. |
| 2158 | k-space based Restoration of Hyperpolarized Xenon-129 MRI | |
1Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, People's Republic of China |
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The magnetization of hyperpolarized media (such as Xenon-129, Helium-3 and Carbon-13) is nonrenewable, which makes it difficult to achieve both high signal-to-noise ratio and good spatial resolution in reconstructed MR images. Consequently, a k-space based restoration method is proposed to improve the quality of hyperpolarized MR images in this study, aiming to improve the visual quality of such images. Moreover, a new descriptor is proposed to measure the visual quality of hyperpolarized MR images. Experimental results demonstrated the proposed method is beneficial in visualizing detailed structures in pulmonary images, such as ventilation fine defects. |
| 2159 | Human Lung Morphometry using Hyperpolarized 129Xe Multi-b Diffusion MRI with Compressed Sensing | |
1School of Physics, Huazhong University of Science and Technology, Wuhan, People's Republic of China, 2Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, People's Republic of China, 3Department of Magnetic Resonance Imaging, Zhongnan Hospital of Wuhan University, Wuhan, People's Republic of China |
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This work is to investigate the feasibility of compressed sensing (CS) on the morphologic measurement of lung microstructure using hyperpolarized 129Xe diffusion magnetic resonance imaging (MRI). The fully sampled (FS) and prospective CS multi-b diffusion MRI data were obtained from five healthy subjects and one COPD patient, respectively. The maps and global average values of mean linear intercept length (Lm) were calculated using cylinder model. The results were compared between FS and CS method for all subjects. The difference between FS and CS ranged from -2.3% to 7.2%. A highly Person’s correlation (R=0.988) between FS and CS was presented. |
| 2160 | MRI Characterization of Lung Lesions from Pulmonary Tuberculosis | |
1Radiology, Cancer Hospital of Chinese Academy of Medical Sciences at Shenzhen, China, Shenzhen, People's Republic of China, 2Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States, 3MR Technical Services, Siemens Healthcare Ltd., People's Republic of China, 4Radiology, Longhua People’s Hospital of Shenzhen, People's Republic of China |
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This work demonstrated that lung MRI can be applied to imaging and characterize the abnormalities and lesions in patients with history of pulmonary tuberculosis (TB) with the validation of clinical CT. Results and examples show that MRI not only offers a non-radiation imaging alternative to CT for the lung examination, but also can provide additional information on lung soft tissue properties. |
| 2161 | Determination of RF and acquisition properties for optimal scan performance in 19F-MRI of inhaled perfluoropropane | |
1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, United Kingdom, 2Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom |
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19F-MRI of inhaled perfluoropropane gas allows assessment of lung ventilation properties with a thermally polarised tracer gas. Due to the scarcity of signal from the non-hyperpolarised gas-phase imaging agent, optimal scan protocol design plays a critical role in image quality. Acquisition variables and coil power performance were modelled to determine the optimal image acquisition parameters for a spoiled gradient echo pulse sequence for human 19F birdcage and chest surface coils. Application of optimised scan protocols to human studies shows acceptable image quality for assessment of lung function. |
| 2162 | 1H MAGNETIC RESONANCE IMAGING OF THE LUNGS USING PROPANE AS AN INHALATION AGENT | |
1Lakehead University, Thunder Bay, ON, Canada, 2Lakehead University, MURILLO, ON, Canada, 3Thunder Bay, ON, Canada |
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We used 80% propane/20% oxygen mixture as an imaging agent and conventional 1H MRI to image the lungs of a living rat. We believe that this is the first time propane gas has been used in vivo for imaging of the lungs. We obtained an SNR approaching 50 from the propane in the lungs. Our results demonstrate that propane has a possibility of being used as a lung imaging modality for detection of various pulmonary diseases. |
| 2163 | A Portable Constant-Volume Ventilator for Rodent Hyperpolarized Gas MRI | |
1Biomedical Engineering, Duke University, Durham, NC, United States, 2Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States, 3Medical Physics Graduate Program, Duke University, Durham, NC, United States, 4Radiology, Duke University Medical Center, Durham, NC, United States |
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Hyperpolarized 129Xe MRI is a powerful probe of lung ventilation, perfusion and gas-exchange. It can be used in both clinical and preclinical settings, where the latter enables rapid discovery of new applications and early testing of therapies in animal models. However, preclinical hyperpolarized gas MRI has been limited to a few expert sites, owing to the challenge of reliably delivering hyperpolarized gas to small animals. Here, we present a constant-volume ventilator that allows for high-resolution hyperpolarized gas imaging and spectroscopy during precisely controlled multi-breath acquisitions. The ventilator is compact, portable, and easy to duplicate and disseminate. |
| 2164 | 2D-Turbo Spin-Echo Sequence with Incremental Trigger Delay Time for Monitoring Vascular Signal Suppression in Peripheral Pulse Gated Black-blood Lung MR Imaging | |
1Department of Clinical Radiology, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan, 2Department of Molecular Imaging and Diagnosis, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan, 3Philips Electronics Japan, Ltd, Tokyo, Japan |
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Breath-hold black-blood magnetic resonance imaging of the lung provides promising results in focal lesion detection. Using peripheral pulse gating, we intended to monitor the degree of vascular suppression and the changes in tissue contrast more closely than in the previously reported methods. Black-blood fat-saturated T2-weighted images were acquired for healthy volunteers with incremental delay time points throughout the pulse cycle. The relative ratios of the specific tissue to the muscle were quantified. The systolic phase provided superior black-blood effects and was considered optimal for signal acquisition. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2165 | Developmental assay with Magnetization Transfer Ratio in non-human primate | |
1Tokyo Metropolitan University, Tokyo, Japan, 2Central Institute for Experimental Animals (CIEA), Kawasaki, Japan, 3School of Medicine Keio University, 4Brain Science Institute, RIKEN |
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MTR reflects the protein content such as myelin of brain. We examined the age-related MTR for common marmosets (1-18 months). Almost all regions of the brain have increased as T1 relaxation similar curve and the rate change of the MTR in each region was different. In voxel-wise analysis, MTR increase shows back-to-front maturation patterns in white matter. This pattern has observed in human studies. MTR can be a good marker to evaluate the normal brain development of common marmoset, and eventually a suitable parameter to assess brain developmental disorders for study, diagnosis, and treatments. |
| 2166 | The Pain of Pre-Clinical fMRI | |
1Psychology, University of Sheffield, Sheffield, United Kingdom, 2Biological Services, University of Sheffield, Sheffield, United Kingdom, 3School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom |
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This study uses multi-parametric MRI measures to further our understanding on the pathophysiology of migraine in a novel preclinical model of medication overuse headache. Rats undergo sustained triptan exposure inducing cutaneous allodynia. Following drug exposure, we perform ASL, NMR, connectivity and evoked response BOLD fMRI to investigate sustained neuronal adaptations/changes. We investigate how drug overuse leads to latent sensitization to migraine triggers 20 days after exposure. We find significantly altered CBF levels in triptan treated animals. NMR reveals changes in GABA & Tau metabolite levels. fMRI shows changes in functional connectivity and activation of brain regions associated with pain pathways. |
| 2167 | Loss of lateral asymmetry in the brain of mouse models of autism | |
1Hospital for Sick Children, Toronto, ON, Canada, 2Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada |
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Examination of lateral asymmetry differences in mouse models related to Autism. Using 42 different mouselines as a representative sample of an autistic population, we show a loss of asymmetry in the mutant mice compared to wild-type that may be indicative of functional and/or behavioural variations. |
| 2168 | Cerebral metabolic and physiological evidence supporting a shift toward glycolysis in a mouse model with congenital anemia. | |
1Radiology, Albert Einstein College of Medicine, Bronx, NY, United States, 2Medicine/Hematology, Albert Einstein College of Medicine, Bronx, NY, United States, 3Albert Einstein College of Medicine, Bronx, NY, United States, 4Physiology & Biophysics, Albert Einstein College of Medicine, Bronx, NY, United States |
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The effect of congenital anemic hypoxia on brain energy metabolism was studied on BERK-Hemi mouse exhibiting poor oxygen delivery secondary to reduced hemoglobin oxygen affinity. Regionally increased CBF in BERK-Hemi mouse was correlated with decreased mean diffusivity and tissue T1. Additionally, BERK-Hemi mouse exhibited elevated concentrations in N-acetylaspartate, glutamate, total choline and glucose in thalamus, but a lower concentration of glutamine. Together, the results suggest BERK-Hemi mice develop a compensatory mechanism which leads to increased glycolysis to combat hypoxia and increased reactive oxygen stress. |
| 2169 | Monitoring glioma heterogeneity during tumor growth using clustering analysis of multiparametric MRI data | |
1U836, Inserm, Grenoble, France, 2Université Grenoble Alpes, Grenoble Institut des Neurosciences, Grenoble, France, 3INRIA, Grenoble, France, 4LJK, Université Grenoble Alpes, Grenoble, France |
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Brain tumor heterogeneity plays a major role during gliomas growth and for the tumors resistance to therapies. The goal of this study was to demonstrate the ability of clustering analysis applied to multiparametric MRI (mpMRI) data to summarize and quantify intralesional heterogeneity during tumor growth. A mpMRI dataset of rats bearing glioma was acquired during the tumor growth (5 maps, 8 animals and 6 time points). After co-registration of every MR data over time, a clustering analysis was performed using a Gaussian mixture distribution model. Although preliminary, our results show that clustering analysis of mpMRI has a great potential to monitor quantitatively intralesional heterogeneity during the growth of tumors. |
| 2170 | Characterization of a Murine High Altitude Exposure Model | |
1Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 2Radiology and Radiological Sciences, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 3Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 4Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States |
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MRI is a useful technology for longitudinal assessments, which are critical for understanding vascular changes in the brain. Exposure to high-altitude (HA), hypoxic conditions, e.g. by military personnel, can result in physiological changes and ultimately degradation of neurobehavioral performance. We utilized in vivo MR imaging in mice to examine changes in brain vasculature, myelination and structure and to provide longitudinal insights into pathological changes caused by long-term exposure to HA. We observed changes in T2 that reflect edema/inflammation, fractional anisotropy changes that suggest changes in white matter myelination, and rCBF and VDi imaging indicating adaptations to HA conditions. |
| 2171 | Modulation of structural and functional networks in the ischemic mouse brain by stem cell therapy | |
1In-vivo NMR, MPI for Metabolism Research, Cologne, Germany, 2Dept. Radiology, Leiden University Medical Center, Leiden, Netherlands |
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In this study we combined rs-fMRI and diffusion MRI to assess the therapeutic capacity of cortically injected human neural stem cells in the mouse brain after stroke during 3 months. Seed-based analysis of diffusion anisotropy maps and functional connectivity were conducted interrelated with the main focus on the effect of stroke and treatment on the contralesional hemisphere. A delayed breakdown in functional network strength for the therapeutically treated group compared to a sham treated group is observed. However, diffusion anisotropy parameters stay stable with an increasing trend for the thalamus. |
| 2172 | Using intravoxel incoherent motion method to evaluate the effect of butylphthalide in middle cerebral artery occlusion rat model | |
1MR Research China, GE Healthcare, Beijing, People's Republic of China, 2Department of MRI, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China |
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Stroke is the third leading cause of death in industrialized countries and the most frequent cause of acquired adult. Butylphthalide has been shown to have protective effects against ischemic stroke. This study would like to observe the temporal evolution of parameters calculated by IVIM model in an experimental middle cerebral artery occlusion (MCAO) rat model, and how the butylphthalide effect the physiological changes. |
| 2173 | In vivo Magnetic Resonance Imaging of the Marmoset Spinal Cord at 7T | |
1TNS/NIB/NINDS, National Institutes of Health, Bethesda, MD, United States, 2CENIR, UPMC-Inserm U1127, CNRS 7225, Institut Cerveau Moelle, Paris, France, 3CMS/LFMI/NINDS, National Institutes of Health, Bethesda, MD, United States, 4VIS/NIB/NINDS, National Institutes of Health, Bethesda, MD, United States |
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When induced to have experimental autoimmune encephalomyelitis (EAE), marmosets can suffer from motor and sensory deficits highly suggestive of lesions located in the spinal cord. In this study, we developed an in vivo spinal cord imaging protocol at 7T for marmosets, and were able to visualize gray and white matter as well as focal EAE lesions. Future work will focus on characterizing the spatiotemporal evolution of spinal cord EAE lesions over the disease course. |
| 2174 | The effects of breastfeeding versus formula-feeding on cerebral cortex maturation in infant rhesus macaques | |
1Neuroscience, Oregon National Primate Research Center, Beaverton, OR, United States, 2Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, United States, 3Casey Eye Institute, Oregon Health and Science University, Portland, OR, United States, 4Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 5Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 6Abbott Nutrition, Columbus, OH, United States |
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Infant rhesus macaques were studies to test the effects of breastfeeding versus formula-feeding on cerebral cortex maturation. Through analysis of structural and diffusion MR images, brain volume over the first 6 months of life was not significantly altered by formula-feeding versus breastfeeding, or by formula lutein supplementation. However, cellular maturation within cerebral cortical gray matter differed between formula-fed and breastfed animals. Lower gray matter FA of breastfed infants is interpreted to reflect greater neuronal arborization. This difference may be related to the different social experience as well as the nutrient composition of breast milk. |
| 2175 | Behavioral and Image Evidence for Mild Traumatic Brain Injury in Rats with the Skull Helmet | |
1Translational Imaging Research Center, College of Medicine, Taipei Medical University, Taipei, Taiwan, 2Department of Radiology, School of Medicine, Taipei Medical University, Taipei, Taiwan, 3Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan, 4Department of Medical Research, Taipei Medical University Hospital, Taipei, Taiwan, 5Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan, 6School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, Taiwan, 7Department of Biomedica, China Medical University, Taichung, Taiwan |
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An experimental model of mild traumatic brain injury (mTBI) mimicking the pathological outcomes in mTBI patients found in |
| 2176 | Post-contrast Signal Enhancement in Dentate Nucleus on Unenhanced T1 Weighted MRI in Rodents | |
1Department for Diagnostic and Interventional Imaging, UT Health Science Center At Houston, Houston, TX, United States |
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Some of the gadolinium based contrast agents are shown to produce enhancements on T1-weighted images long after their administration in certain brain structures in humans, raising questions about the safety of these agents. The enhancement is thought to be due to dechelation of the contrast agents. Understanding the pathophysiological effects requires systematic pre-clinical studies. As a first step towards this goal we conducted longitudinal in vivo studies in rodents administered Magnevist and Omniscan for ten days to quantify the temporal profile of enhancement using relaxometry and investigate if this enhancement has an effect on the tissue microstructure. Our results show that Ominiscan lowers both T1 and T2 starting from week 2 post contrast administration. However, such changes were not observed in Magnevist and saline treated animals. The contrast agents do not appear to have significant effect on any of the DTI measures. |
| 2177 | Altered Cerebral Blood Flow and Cerebrovascular Function after Voluntary Exercise in Adult Mice | |
1Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON, Canada, 2Sunnybrook Research Institute, Toronto, ON, Canada, 3Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada |
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A longitudinal study employing continuous arterial spin labelling MRI with a hypercapnic challenge was used to examine changes in cerebral blood flow with physical exercise in healthy, adult mice. We found that exercise resulted in increases in the normocapnic and hypercapnic blood flow in the hippocampus and that these changes were positively correlated to the volume of the hippocampus following exercise. Interestingly, hypercapnic hippocampal blood flow prior to exercise was predictive of the distance subsequently run and exposure to this voluntary exercise regime was found to reduce these pre-existing blood flow differences. |
| 2178 | Altered nigrostriatal system in the MPTP Squirrel Monkey model revealed by diffusion MRI at 11.7T. | |
1Center for Neuroimaging Research, Brain and Spine Institute, Paris, France, 2CNRS UMR 7225/INSERM 1127/UPMC UM75, Brain and Spine Institute, Paris, France |
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Parkinson’s disease (PD) is characterized by neurodegeneration of the dopaminergic neurons in the substantia nigra pars compacta (SNc). The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxin can induce Parkinson syndrome in primate models. We evaluated the nigrostriatal (NS) pathway degeneration in MPTP Squirrel monkeys using diffusion MRI. The results showed significantly increased fractional anisotropy in all NS regions of the MPTP group (SN, caudate and putamen regions). Axial diffusivity also significantly increased in the SN and caudate regions, while radial diffusivities did not show any differences, except a significantly decreased λ3 in the putamen. Those results should help develop preclinical evaluation of PD therapeutics. |
| 2179 | Allosteric activation of mGluR4 receptor reversing social behavior deficits modifies the reward-related resting state networks in mu opioid receptor knock-out mice | |
1Medical Physics, University Medical Center Freiburg, Freiburg, Germany, 2Faculty of Biology, Albert-Ludwig-University Freiburg, Freiburg, Germany, 3Department of Psychiatry, Douglas Hospital Research Center, School of Medicine, McGill University, Montreal, QC, Canada, 4Engineering Science, Computer Science, and Imaging Laboratory, Integrative Multimodal Imaging in Healthcare, University of Strasbourg, Strasbourg, France, 5Department of Biophysics and Nuclear Medicine, University Hospital Strasbourg, Strasbourg, France |
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Mu opioid receptor (MOR) knock-out Oprm1-/- mice exhibit deficits in social behavior and repetitive behavior, which are phenotypes related with autism spectrum disorders (ASD). Thus, MOR deficient mice were recently proposed as monogenic models of ASD. Moreover, a decrease in metabotropic glutamate receptor 4 (mGluR4) levels was found in these mice. A treatment with VU0155041, an allosteric modulator of mGluR4, reversed behavioral deficits in Oprm1-/- mice. Here, we investigated the remodeling on brain connectivity level in Oprm1-/- mice under VU0155041-treatment and found enhancement of positive correlation towards frontal brain areas involved in reward-processing due to the compound. |
| 2180 | Measuring of Whole Brain Perfusion in the Awake Marmoset Using Continuous Arterial Spin Labeling | |
1Cerebral Microcirculation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States, 2Biomedical Engineering, Texas A&M University, College Station, TX, United States |
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The common marmoset, a small New World primate, is a popular non-human primate for transgenic lines of brain disease models and 3D printed helmets to immobilize the head for awake MRI. However, cerebral blood flow (CBF), a crucial component to normal brain functions, has not been measured to date in awake marmosets. In this study, we demonstrate the feasibility of measuring whole brain CBF in the awake marmoset using a continuous arterial spin labeling MRI sequence and dedicated hardware, comprising of a spin-labeling coil and a novel 10-channel phased array in a 7T animal MRI system. |
| 2181 | Learning-based Segmentation for Monkey Brain MRI | |
1Department of Information Engineering, Liuzhou City Vocational College, Liuzhou, People's Republic of China, 2Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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Accurate segmentation of monkey brain MRI is of great importance in studying the brain development, pathogenesis and progression of neurological diseases. However, it is challenging for automatic segmentation due to noise, low |
| 2182 | In vivo Diffusion tensor imaging to unravel the contribution of thyroid hormones in seasonal neuroplasticity in European Starlings (Sturnus vulgaris) | |
1Bio-Imaging Lab, University of Antwerp, Wilrijk, Belgium, 2Laboratory of Comparative Endocrinology, KU Leuven, Leuven, Belgium |
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The effect of thyroid hormones on seasonal neuroplasticity in adult songbirds was never investigated before. To study this we treated photorefractory starlings with methimazole, which resulted in a depletion of thyroid hormones plasma levels. Using repeated measures of in vivo DTI and song recordings, neuroplasticity and song behaviour were monitored over different photoperiods. We found indications that thyroid hormones can modulate the seasonal neuroplasticity both directly at the level of the song control system, as suggested by direct changes in song behaviour after methimazole-treatment, and indirectly via the hypothalamus-pituitary-gonad axis, as methimazole-treatment inhibited the testosterone increase upon photostimulation. |
| 2183 | Enhanced neuroplasticity by physical exercise for hypoxic ischemic injured rat brain monitored by BOLD-fMRI | |
1Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, Korea, Republic of, 2Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Korea, Republic of, 3Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of, 4Center for Molecular and Cellular Imaging, Samsung Biomedical Research Institute, Seoul, Korea, Republic of, 5Department of Global Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of |
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Physical exercise is known to boost the spontaneous recovery, but the exact mechanism for exercise induced recovery after brain injury is not clearly known. In this study, we show enhanced neuroplasticity with physical exercise on the intact side as well as the damaged side for the HI injured rat brain by calculating the brain activation maps from BOLD-fMRI: Increased inter-hemispheric transfer and intra-hemispheric extension of activated areas were observed with physical exercise covering the widespread sensory-motor related areas in the contralesional hemisphere. |
| 2184 | Quantification of vascular water transport using time-resolved pulsed arterial spin labelling MRI at 9.4 T | |
1Medical Radiation Physics, Lund University, Lund, Sweden, 2Lund University Bioimaging Centre, Lund University, Lund, Sweden, 3Centre for Mathematical Sciences, Lund University, Lund, Sweden, 4Department of Radiology (Adjunct), Johns Hopkins School of Medicine, Baltimore, MD, United States |
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In this study, an improved quantification approach for measuring ASL transit-time parameters is proposed. The concept is based on multi-TI ASL measurements, where the dynamics of the inverted spins are described by the Fokker-Planck equation. The random forces in this equation are assumed to occur due to pseudo-diffusion in the capillaries and subsequent filtration through the blood brain barrier (BBB). The obtained time for the intravascular water to distribute from arteries through the capillary bed and into the parenchyma can, for example, be related to the capillary function as well as to the integrity of the BBB. |
| 2185 | Phenotyping of transgenic Huntington’s disease minipigs by MR spectroscopy | |
1Department of Clinical Radiology, University Hospital Muenster, Muenster, Germany, 2George-Huntington-Institute, Muenster, Germany |
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Huntington’s Disease (HD) is a fatal neurodegenerative disorder, caused by a single genetic mutation, and characterized by deficits in motor coordination, behavior and cognition. A transgenic minipig model of HD has been established. Here, we employ single voxel MRS at 3 T to acquire metabolic profiles from the brain of this model over four years. We show that seven metabolite combinations can be quantified in adolescent and adult minipigs. Pathologic alterations in the phenotype were not observed at the age studied. |
| 2186 | Perturbed development of rhesus macaque fetal cerebral cortex and white matter in an IUGR pregnancy, secondary to placental insufficiency, characterized by in utero diffusion MRI | |
1Advanced Imaging Research Center, OHSU, Portland, OR, United States, 2Department of Obstetrics and Gynecology, OHSU, 3Pediatrics, Bioengineering, and Radiology, University of Washington, Seattle, WA |
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In utero diffusion and anatomical MRI measurements were performed on a naturally occurring intrauterine growth restriction (IUGR) and 3 control pregnant rhesus monkeys. Water diffusion anisotropy (FA) within fetal cerebral cortex as well as white matter was used to characterize abnormal development in the IUGR fetal brain. Markedly higher cortical FA, indicating aberrent morphogenesis of cortical neurons, was observed in the IUGR fetal brain compared to controls. In addition, significantly reduced FA in a number of white matter tracts was also found in the IUGR fetal brain, reflecting perturbed white matter development. |
| 2187 | Effects of first-trimester alcohol exposure on fetal brain development characterized by in utero diffusion MR | |
1Advanced Imaging Research Center, OHSU, Portland, OR, United States, 2Pediatrics, Bioengineering, and Radiology, University of Washington, 3Division of Neuroscience, Oregon National Primate Research Center |
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To assess the impact of first-trimester ethanol consumption on rhesus macaque fetal brain development, we employed anatomical and diffusion MRI to characterize macroscopic as well as cellular-level changes in ethanol exposed fetuses relative to controls at gestation days (G) 110 and G135. At both time points, perturbed brain maturation indicated by decreased brain volume, cortical surface area, and folding was seen in the ethanol exposed group. In addition, a trend for higher cortical water diffusion anisotropy seen in ethanol exposed group at G110 indicates abnormal dendritic differentiation. |
| 2188 | Anatomical and diffusion MRI fetal brain templates for the rhesus macaque at gestation days 85, 110, and 135 | |
1Advanced Imaging Research Center, OHSU, Portland, OR, United States, 2Pediatrics, Bioengineering, and Radiology, University of Washington |
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In utero T2-weighted (T2W) and diffusion MR images were acquired from control rhesus macaque fetuses at gestation days 85, 110, and 135. High-resolution T2W volumes and diffusion MR volumes were reconstructed using retrospective motion-correction techniques. Population-averaged T2W templates and fractional anisotropy (FA) templates were generated for each time point. Development of fetal tissue zones and gyrification of cerebral cortex were assessed using the T2W templates. In addition, morphogenesis of cortical neurons and maturation of white matter tracts were also characterized using the FA templates. |
| 2189 | USPIO-enhanced magnetic resonance imaging of N-ethyl-N-nitrosourea- induced endogenous rat gliomas: contribution of USPIO-related iron-loaded microglia to signal changes | |
1Radiology, Shiga University of Medical Science, Otsu, Japan, 2Radiology, Kohka public hospital, Kohka, Japan, 3Shiga University of Medical Science, Otsu, Japan |
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We assessed whether ultrasmall superparamagnetic iron oxide (USPIO) phagocytosed by microglia contribute to tumor enhancement in MR imaging of N-ethyl-N-nitrosourea (ENU)-induced endogenous rat brain gliomas by comparing MR images with the corresponding histological sections. USPIO-enhanced MR imaging may provide pure vascular bed images in the early phase within 6 hours after intravenous administration of USPIO agent because it was histologically proved that the administrated agent remained within intravascular space. In the late phase at 63-66 hours after the administration, USPIO-enhanced Gradient-Recalled-Echo T2-weighted images may depict the distribution of microglia that were magnetically labeled by USPIO agent. |
| 2190 | Optical control of blood flow in naive animals | |
1U1128, INSERM, Paris, France, 2U979, INSERM, Paris, France |
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Optogenetics is increasingly used to map brain activation using techniques that rely upon functional hyperemia, for example opto-fMRI. Here we demonstrate that light stimulation protocols similar to those commonly used in opto-fMRI increase blood flow in mice that do not express light sensitive proteins. These results impose careful consideration on the use of photo-activation in studies involving blood flow regulation and suggest light could be used as a technical or therapeutic tool to locally increase blood flow in a controlled fashion. |
| 2191 | Longitudinal Analysis of Rhesus Monkey Brain Development Using Tensor-Based Structural Morphometry | |
1Radiology Informatics and Image Processing Laboratory, Wake Forest School of Medicine, Winston Salem, NC, United States, 2Department of Radiology, Wake Forest School of Medicine, Winston Salem, NC, United States, 3Department of Biomedical Engineering, Wake Forest School of Medicine, Winston Salem, NC, United States, 4Clinical and Translational Sciences Institute, Wake Forest School of Medicine, Winston Salem, NC, United States |
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Translational research models using brain MRI to study non-human primates (NHPs) can provide insight into normal/abnormal human neurodevelopment. In particular, voxel-wise longitudinal imaging designs can characterize the trajectory of change in brain structure among individual subjects. This study analyzes morphometric changes among a cohort of rhesus monkeys during late infancy, revealing total brain volume decreases driven by local volumetric contraction in frontal, parietal and temporal lobes. Characterizing NHP neurodevelopment may facilitate our understanding of complex normal and delayed human brain development, and provide a model to evaluate the influence of postnatal experiences on brain structure, cognitive ability and social behaviors. |
| 2192 | Developmental morphometry of the marmoset brain from infancy to adulthood | |
1Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom, 2Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom, 3Dept of Physiology, Development and Neuroscience, University of Cambridge, 4Dept of Psychology, University of Cambridge, 5Dept of Psychiatry, University of Cambridge |
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Understanding the development of brain circuits through infancy to adulthood is crucial in determining the causes of mental health disorders, half of which are established before early adulthood. We use MRI to track the development of >200 discrete brain regions in a longitudinal primate brain study of 41 marmosets. Tensor-based morphometry indicated key regions of myelination from 3-6 months of age, and clustering of growth trajectories fitted with cubic splines allowed parcellation of regions based on growth patterns. We present maps of development showing differing patterns and rates of growth not only across lobes but between primary and associative areas. |
| 2193 | Dynamic Longitudinal DTI Metric Changes of Hippocampus in Developing Non-Human Primate | |
1Keio University School of Medicine, Tokyo, Japan, 2Riken, Wako, Japan, 3Central Institute for Experimental Animals, Kawasaki, Japan |
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We investigated typical hippocampal development of a non-human primate model, common marmoset, using longitudinal DTI metrics data. Our findings showed dynamical non-linear developmental changes of hippocampal volume, MD and RD especially in its anterior part and suggested its neural turning point would be at puberty. These findings would give insights of disorder and disease of onset specific to developmental period. |
| 2194 | Dynamic uptake of manganese in the developing mouse brain | |
1Skirball Institute of Biomolecular Medicine, NYU School of Medicine, New York, NY, United States, 2Department of Chemistry, SUNY Plattsburgh, Plattsburgh, NY, United States |
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Manganese-enhanced MRI (MEMRI) is a powerful technique for imaging rodent neuroanatomy. We investigated differences in the uptake of paramagnetic manganese ions (Mn2+) in the mouse brain at two postnatal days: P7 and P21. We observed higher uptake of Mn2+ in all neuroanatomical regions-of-interest (ROIs) at P7; this increased uptake was reflected in the shorter T1 times at P7 relative to P21. We also observed faster clearance of Mn2+ within the ventricles at P21. Our findings highlight the spatiotemporal differences in Mn2+ uptake and may be useful when planning MEMRI studies in the developing mouse brain. |
| 2195 | Morphological growth patterns in common marmoset developing brain | |
1Department of Physiology, Keio University, Tokyo, Japan, 2Central Institute of Experimental Animals, 3Laboratory for Marmoset Neural Architecture, RIKEN BSI, 4Okinawa Institute of Science and Technology Graduate University |
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The postnatal brain development at the macroscale in common marmoset has been studied based on the volume measurement, as is not well-studied despite its importance. Maximizing the feature that it takes only 2 years to reach adulthood, the longitudinal MRI was conducted for 23 subjects. The volume of gray matter was inverted U curve trajectories, while increase of white matter became stable around 12 months old. Developmental patterns of regions in cerebral cortex were similar to gray matter but different in developmental timing. The study can demonstrate overall growth patterns were similar to patterns previously reported in humans and other monkeys. |
| 2196 | Voxel Based Alterations in White Matter Volume following Lipophilic Iron Treatment | |
1Neural and Behavioral Sciences, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, 2Neurosurgery, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, 3Radiology, The Pennsylvania State University - College of Medicine, Hershey, PA, United States |
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We show that there are observable VBM changes in white matter and grey matter fractions of an aging mouse and these changes are attenuated with a lipophilic high iron diet. This data support the hypothesis that regressive white matter degeneration may be prevented with increased access to CNS iron. Animals that do not have brain iron overloading show longitudinal white matter changes not observed in the iron loaded animals. Furthermore, our data supports the white matter retrogenesis model observed in the aging human brain. |
| 2197 | Fast macromolecular proton fraction mapping validated in the murine model of cuprizone induced demyelination | |
1Laboratory of Neurobiology, Tomsk State University, Tomsk, Russian Federation, 2N.N.Vorozhtsov Novosibirsk Institute of Organic Chemistry, Russian Federation, 3Institute of Cytology and Genetics, Novosibirsk, Russian Federation, 4N.N.Vorozhtsov Novosibirsk Institute of Organic Chemistry, Novosibirsk, Russian Federation, 5Siberian State Medical University, Tomsk, Russian Federation, 6Department of Radiology, University of Washington, Seattle, WA, United States |
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A recently developed quantitative MRI method, fast macromolecular proton fraction mapping (MPF) has shown a promise as a biomarker of myelin in human and animal studies with a particular advantage of sensitivity to grey matter (GM) demyelination. This study aimed to histologically validate the capability of MPF mapping using the cuprizone demyelination model. MPF strongly correlated with quantitative histology in all animals (r=0.95, p<0.001) as well as in treatment and control groups taken separately (r=0.97, p=0.001 and r=0.95, p=0.003, respectively). Close agreement between MPF and histology suggests that fast MPF mapping enables robust and accurate quantitative non-invasive assessment of demyelination. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2198 | Changes of metabolite levels with low SNR in brain tumours measured by hybrid FET PET and 3D MRSI | |
1Institute of Neuroscience and Medicine, Medical Imaging Physics (INM-4), Forschungszentrum Jülich, Jülich, Germany, 2Department of Nuclear Medicine, Faculty of Medicine, RWTH Aachen University, Aachen, Germany, 3Miller School of Medicine, University of Miami, Miami, FL, United States, 4Department of Neuroradiology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany, 5Department of Neurology, Faculty of Medicine, JARA, RWTH Aachen University, Aachen, Germany |
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The specificity of MR based diagnosis of gliomas may be improved by O-(2-[18F]fluoroethyl)-L-tyrosine (FET) uptake measured with PET and metabolite changes obtained from simultaneously acquired volumetric MR spectroscopic imaging. In order to cope with low SNR of the metabolites, the MR spectra of 25 patients were subject-specifically averaged within the tumour borders transferred from FET PET and compared to non-affected white matter of the contra lateral side. Strongest signal drops were found for GLU (0.58±0.43, WHO II) and NAA (0.33±0.13, WHO II-IV), strongest increase for CHO/NAA (3.9±2.4). The metabolite changes showed no dependency on tumour grade. |
| 2199 | Proton MR spectroscopy detection of high lipid levels without central necrosis and high intensity on DWI is characteristics of germinoma | |
1Neurosurgery, Hiroshima University, Hiroshima, Japan, 2Clinical Oncology & Neuro-oncology Program, Hiroshima University Hospital, Hiroshima |
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MRS and DWI of germinoma |
| 2200 | Parameter Estimation in a Mathematical Model of Murine Glioma from MR Imaging | |
1Mathematical & Statistical Sciences, Arizona State University, Tempe, AZ, United States, 2Mathematics, North Carolina State University, Raleigh, NC, United States, 3Mathematics, University of Arizona, Tucson, AZ, United States, 4Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, 5Neuro-Oncology Research, Barrow Neurological Institute, Phoenix, AZ, United States, 6BNI-ASU Center for Preclinical Imaging, Barrow Neurological Institute, Phoenix, AZ, United States, 7Neurosurgery Research, Barrow Neurological Institute, Phoenix, AZ, United States |
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This study assesses the feasibility of estimating and quantifying the uncertainty in growth parameters for a mathematical model of glioma growth from MR imaging. Five immunocompetent albino mice were inoculated intracranially with syngeneic GL261 tumor cells and followed by serial imaging for 25 days. We simulated the growth of the tumor from the known initial conditions using a popular two-parameter reaction-diffusion model and compared the results with the imaging. Our simulations show that the growth and diffusion rates in the model cannot be identified from imaging data alone. Uncertainty quantification in model predictions of the tumor is problematic. |
| 2201 | Anticorrelated networks dysfunction in patients with brain tumor in frontal lobe | |
1Department of Medical Imaging, The First Affiliated Hospital of Xi'An Jiaotong University, Xi'An, People's Republic of China, 2Key Laboratory of Biomedical Information Engineering of Education Ministry, Institute of Biomedical Engineering, Xi’an Jiaotong University, 3Department of Electronics Engineering, Northwestern Polytechnical University, 4Technical University Munich, 5Department of neurosurgery, The First Affiliated Hospital of Xi'An Jiaotong University, Xi'An, People's Republic of China |
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The aim of this study is to evaluate whether the lesion in frontal lobe would cause the change of brain positive and negative network interaction, thereby affecting cognitive function. We employed a MSIT to compare the task-positive and DMN changes of brain tumor patients and the healthy controls. Our results indicated the interaction relationship between the task-positive and DMN in patients with brain tumor in the frontal lobe was significantly decreased. We suggest that reduced anti-correlation between DMN and task-positive networks in patients with brain tumor may be caused by dysfunctional DMN, thus affecting the cognitive function of patient. |
| 2202 | Default Mode Sub-network in Brain Tumor: A Resting State fMRI Study | |
1Department of Medical Imaging, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, People's Republic of China, 2Key Laboratory of Biomedical Information Engineering of Education Ministry, Institute of Biomedical Engineering, Xi’an Jiaotong University, Xi'an, People's Republic of China, 3Department of Electronics Engineering, Northwestern Polytechnical University, Xi'an, People's Republic of China, 4Technical University Munich |
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The aim of the study was to observe the activation of DMN in patients with different types and location brain tumors, and as so to investigate whether the type and location of tumor would affect DMN spatial distribution. In our study, we compared the spatial distribution of DMN both glioma and meningioma. Finally, our findings show that DMN integrity is impaired as a result of tumor, and the DMN spatial distribution could be affected by the location of the brain tumor. |
| 2203 | In Vivo 3D Metabolic Correlation Mapping using 1H Echo Planar Spectroscopic Imaging in IDH-mutant Gliomas at 3T | |
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States |
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We present a 3D high resolution 2HG and other metoblites imaging in gliomas with metoblic correlation mapping technique to differentiate areas with different metabolic activities. |
| 2204 | Texture analysis of diffusion weighted imaging for the evaluation of tumor heterogeneity based on different regions of interest | |
1The affiliated hospital of xuzhou medical university, Xuzhou, People's Republic of China, 2GE healthcare china |
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Texture analysis of DWI based on different ROI can provide various significant parameters to evaluate tumor heterogeneity, which were correlated with tumor grade. Particularly, the inhomogeneity value derived from whole tumor ROI provided high diagnostic value in differentiating HGGs from LGGs and predicting the status of tumor proliferation. |
| 2205 | Reproducibility of 3D short TE MRSI in patients with high-grade glioma | |
1Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States |
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The study evaluated the reproducibility of metabolite profiles within the normal appearing white matter that were acquired using automatic prescription of short echo time magnetic resonance spectroscopic imaging for ten patients with high grade glioma. |
| 2206 | Whole tumor volume based histogram analysis of ADC for differentitating between WHO grade II and III glioma | |
1First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China, 2GE Healthcare,China,Beijing, 3GE Healthcare,Lifescience,China |
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In this study, the differential diagnostic value of histogram analysis of ADC signal value based on entire region of grade II and III tumor is investigated, and further aimed at revealing the microscopic changes of glioma in the evolution of low grade to high grade.Conclusion that,histogram analysis of ADC signal value based on entire tumor could provide more information in differentiation of grade II and III glioma. Several parameter showed superior diagnostic value. |
| 2207 | Quantitative analysis of MR diffusion-weighted imaging for differential diagnosis of cerebral alveolar echinococcosis and brain metastases | |
1MRI Room，First Affiliated Hospital，Xinjiang Medical University, Urumqi 830011, China, Urumchi, People's Republic of China, 2Department of Neurosurgery，First Affiliated Hospital，Xinjiang Medical University, Urumqi 830011, China |
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Synopsis：This study aims to probe the role of the quantitative analysis of MR diffusion-weighted imaging in differentiating Cerebral Alveolar Echinococcosis (CAE) with Brain metastases (BM).There was significant difference of the mean ADC values and eADC values (P<0.05) of the solid region between CAE and BM. There was no significant difference of the mean ADC values (P＞0.05) between CAE and BM，but there was significant difference that of the eADC values (P<0.05). MR-DWI was valuable for making diagnosis and differential diagnosis of patients with CAE and BM. EADC values is better than the ADC values. |
| 2208 | Do gadolinium-based contrast agents alter 23Na T1 relaxivity in glioma? | |
1Department of Radiology, University of Cambridge, Cambridge, United Kingdom, 2Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom, 3GE Global Research, Munich, Germany, 4Neurosurgery Division, Dept. of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom |
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Incomplete fluid suppression on fluid-attenuated inversion-recovery 23Na-MRI (IR-23Na-MRI) was observed in three patients undergoing IR-23Na-MRI after gadolinium contrast injection, as part of a brain tumour imaging study. To evaluate this, 23Na-MRI T1 maps were acquired before and after injection of a gadolinium-based contrast agent on a grade IV glioma (GBM) patient, which showed a statistically significant change of 23Na-MRI T1 within the peritumoral oedema (p=0.0095). Gadolinium contrast-enhanced 23Na-MRI could potentially add further applications for sodium imaging and probe tumour tissue structure in new ways to investigate proliferation and treatment response. |
| 2209 | Can q-space imaging differentiate meningioma from cranial nerve schwannoma? | |
1Radiology, Kyoto Prefectural University of Medicine, Kyoto, Japan, 2Radiological Sciences, David Geffen School of Medicine at UCLA, 3Radiology, Johns Hopkins University, 4Neurosurgery, Kyoto Prefectural University of Medicine, Kyoto, Japan |
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Q-space imaging (QSI) is an extended version of diffusion weighted image technique which can be utilized for observing microstructure of brain in micrometer order. In order to assess whether QSI can differentiate between the two most common extra-axial brain tumors of the posterior fossa, we performed histogram analyses as well as ROC analyses on the q-space data of meningioma and cranial nerve schwannoma (CNSch). We also assessed the apparent diffusion coefficient (ADC) for comparison. As a result, we have shown that mean displacement derived from QSI as well as ADC are able to differentiate meningioma from CNSch. |
| 2210 | Identifying Isocitrate Dehydrogenase Genotype in Low-grade Glioma Non-invasively using Amide Proton Transfer-Weighted (APTW) Imaging | |
1Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Department of Radiology, Southern Medical University, Zhujiang Hospital, Guangzhou, People's Republic of China, 3Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4Department of Pathology, Southern Medical University, Zhujiang Hospital, Guangzhou, People's Republic of China |
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We explored the radiographic features of isocitrate dehydrogenase (IDH) wildtype and mutated tumors in glioma patients preoperatively using APTW imaging at 3 Tesla. 26 patients with newly suspected low-grade gliomas were recruited, surgical specimens were obtained for pathological analysis, and corresponding APTW signal intensities were recorded. Results showed that the IDH1 wild-type tumors had significantly higher APTW signal intensity than the IDH1 mutant tumors. The area under the ROC curve (AUC) for APTW to differentiate IDH1 wild-type from IDH1 mutant was 0.750. APT imaging has the potential for discriminating IDH genotypes in WHO grade-II gliomas. |
| 2211 | Influence of leakage correction on DSC-based CBV values acquired without and with prebolus in human high-grade glioma | |
1Department of Neuroradiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany, 2Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany |
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Aim of this study was to investigate the influence of leakage correction methods on dynamic susceptibility contrast (DSC)-based measures of cerebral blood volume (CBV), using patient data acquired with and without pre-bolus. Two post-processing techniques were compared with respect to normalized CBV (nCBV) in contrast enhancing tumor tissue. Generally, CBV increased or decreased after leakage correction for data acquired without or with prebolus, respectively. The best agreement between corrected nCBV values, obtained in the same patients without and with prebolus, respectively, was obtained for a reference curve-based correction approach. |
| 2212 | Multimodal study of treated brain tumours combining non-Gaussian diffusion MRI and 18F-FET-PET | |
1Institute of Neuroscience and Medicine 4, Research Centre Jülich, Jülich, Germany, 2Department of Neurology, Faculty of Medicine, JARA, RWTH Aachen University, Aachen, Germany, 3Institute of Nuclear Physics, Faculty of Mathematics and Natural Sciences, University of Cologne, Cologne, Germany, 4JARA - BRAIN - Translational Medicine, RWTH Aachen University, Germany |
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PET using O-(2-18F-fluoroethyl)-L-tyrosine (18F-FET) provides important diagnostic information in brain tumours. In this work, we report a novel combined application of PET imaging and MRI with advanced non-Gaussian diffusion MRI methods including diffusion kurtosis imaging and gamma-distribution function imaging. This is the first multimodal study combining metabolic information from FET-PET and microstructural information gained from non-Gaussian diffusion models. The main goal was to investigate the advantages of such a combined application in tumour assessment and to compare the sensitivity of various non-Gaussian diffusion metrics to the underlying microstructural tissue properties. |
| 2213 | Relating the Evolution of RT-Induced Vascular Injury to surrounding white matter microstructure in Adult Glioma Patients | |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States |
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In the treatment of gliomas, radiation therapy (RT) is associated with long-term effects including vascular injury in the form of cerebral microbleeds (CMBs), and changes in the white matter and thickness of cortex. Ultra high-field MRI techniques were used to characterize RT-induced changes across serial scans in support of ongoing investigations of the role of anti-angiogenic therapies in minimizing treatment effects. Steady increases in the number of CMBs was observed decades post-RT. CMB foci were characterized by increased isotropic diffusion when compared to surrounding white matter, which showed signs of degradation in as few as two months between serial scans. |
| 2214 | Differentiation of glioblastoma and primary central nervous system lymphoma by using MR image-based texture features | |
1Department of Radiology, The University of Tokyo, Tokyo, Japan, 2Department of Radiology, The University of Tokyo Hospital, Tokyo, Japan, 3Department of Radiology, International University of Health and Welfare Mita Hospital, Tokyo, Japan |
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We evaluated the feasibility of machine learning-based differentiation between glioblastoma and primary central nervous system lymphoma by using texture features of post-contrast MR images. Cross validation showed that more than 80% of teacher data were correctly assigned. Trial data comprised of atypical image variants were correctly assigned in up to 78.6% by the best classifiers. |
| 2215 | Effect of Lesion-related Signal Variation in Proton Density Reference Image on Blood Flow Quantification with Arterial Spin Labeling MRI for Differentiating Pseudo-progression from True Progression in Gliomas | |
1Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States, 2Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States, 3Department of Radiology, University of California, San Diego, La Jolla, CA, United States, 4Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States |
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CBF quantification using ASL is an important MR technique for the evaluation of suspicious enhancing lesions for patients’ status post chemotherapy treatment. The quantification requires an estimate of equilibrium magnetization of blood which is often obtained using a set of proton density (PD) reference images; however, this approach can lead to errors in CBF based on tissue variation in PD which could then lead to inaccurate assessment of pseudo-progression (PsP) versus true progression (TP). Our work showed that PD variation led to a reduced diagnostic performance of CBF particularly in the region of enhancing lesions with pathologic proven TP. |
| 2216 | Effect of Lesion Contaminated Nuisance Regressors on Resting-state fMRI Connectivity in Patients with Brain Tumors | |
1Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States, 2Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, 3Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, 4Departments of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center |
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Resting-state fMRI has been shown its potential for pre-surgical mapping. The potential confounds are commonly removed by regressing out the averaged fluctuation over masks of white matter and cerebrospinal fluid. However, for the patients with brain lesions, these masks may be contaminated by lesions. In current study, we generated masks by segmentation and template approaches. Although these masks were contaminated by lesion in most of our patients, no significant difference in FC was found due to this effect, which might be related to small samples. Comparing to segmentation approach, more variable results were observed when masks obtained by template approach. |
| 2217 | Exploring the distribution of inflow and outflow bloodstream type in pituitary adenoma by dynamic contrast-enhanced MRI | |
1Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, People's Republic of China, 2ISN Lab, Xidian University |
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In this study, a new approach for assessing distribution of bloodstream inflow and outflow type based on the three-time point (3TP) method was used to semi-quantitative analysis of the microcirculation characteristics in whole pituitary adenoma by dynamic contrast-enhanced MRI (DCE-MRI). The volume percentage of persistently enhancing type of time-intensity curve (TIC) in adenoma was higher than normal region. Meanwhile, adenomas with hyperprolactinemia were shown a significant decrease of volume percentage in speed up the downhill type when compared with the adenoma without hyperprolactinemia. This method could identify the different distribution of vascularity between normal pituitary and subtype of adenoma. |
| 2218 | Application of High B-value Diffusion-Weighted Imaging in Defining High-grade Glioma Infiltration Regions | |
1MRI Room，Department of Imaging Center, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, People's Republic of China, 2MRI Room，Department of Imaging Center, The First Affiliated Hospital of Xinjiang Medical University, 3Department of Neurosurgery, The First Affiliated Hospital of Xinjiang Medical University |
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Objective To evaluate the role of the ADC value in patients with high-grade glioma (WHO III-IV) using high B-value diffusion weighted imaging (DWI), as a potential noninvasive quantitative index in defining the boundary of glioma. Methods 25 cases of surgical pathologically confirmed glioma underwent the DWI scan with b=1000 and 3000s/mm2 respectively in a 3T MR scanner. The ADC values of the glioma substantial zone, cerebral parenchyma within 0-10/10-20mm radium and the cerebral parenchyma of the opposite sphere are statistically analyzed by SPSS17.0. Results When b=1000 and 3000 s/mm2, the difference in the ADC values of the tumor and the 0-10mm region had no statistical significance(P>0.05). When b-value = 1000 s/mm2, there is statistically valid difference among ADC values of 10-20mm area, lesions and comparing group (P<0.05); When b-value =3000 s/mm2, there is no statistically valid difference among ADC values of 10-20mm area and lesions（P>0.05）. The ADC value of 10-20mm area is validly lower than the lesions. Conclusion The ADC value in high B value DWI scan indicating that the ADC value is more sensitive in quantitatively analyzing the infiltration zone of glioma relative to the low B value DWI scan. |
| 2219 | The value of vessel size imaging in grading oligodendroglioma | |
1Daping Hospital & Research Institute of Surgery, Chongqing, People's Republic of China |
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Applying vessel size imaging(VSI) and dynamic susceptibility contrast MR (DSC-MR) to explore difference of the microvessel between grade Ⅱ and Ⅲ oligodendroglioma. We discovered both VSI and DSC-MR could identify different grades of oligodendroglioma, but the power of VSI was better than DSC-MR. |
| 2220 | Radiographic Atlas of Tumor Growth Pattern in Glioblastoma | |
1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, NTNU, Trondheim, Norway, 2Department of Neurosurgery, St. Olav’s University Hospital, Trondheim, Norway, 3Norwegian National Advisory unit for Ultrasound and Image Guided Therapy, St. Olav’s University Hospital, Trondheim, Norway, 4Department of Medical Technology, SINTEF, Trondheim, Norway |
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In this study we assess the growth pattern of one of the most aggressive brain tumor in adults. Surgery is a standard of care for these patients, and understanding the prominent growth direction of tumor lesions can eventually benefit surgical planning. Contrast-enhanced MR data at two time-points of diagnosis and pre-operation were analyzed to derive mean 3D vector field demonstrating the growth directions. A DTI white matter (WM) atlas was used to investigate the degree of agreement and alignment of the generated vector field towards white matter fibers. |
| 2221 | Differentiation of Brain Infections from Necrotic Glioblastomas using Diffusion Tensor Imaging and Perfusion Weighted Imaging | |
1Radiology, UNIVERSITY OF PENNSYLVANIA, PHILADELPHIA, PA, United States, 2Biological Anthropology, National Research Centre, Cairo, Egypt, 3Cellular and Molecular Physiology, University of Liverpool, Liverpool, United Kingdom |
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To determine whether combined use of diffusion and perfusion MRI can help in differentiating brain infections from glioblastomas (GBMs), 13 patients with infections and 20 patients with GBMs underwent DTI and DSC-PWI. Significantly lower median values of mean diffusivity (MD) and higher fractional anisotropy (FA) were observed in central core of infective lesions than in GBMs. Additionally, significantly decreased median and maximum values of relative cerebral blood volume (rCBV) from enhancing region were observed in patients with infections compared with those of GBMs. The best classification model consisted of MD from central core and rCBVmax from enhancing region. |
| 2222 | The diagnostic performance of DCE-MRI in differentiating high-from low-grade gliomas: A systematic review and meta-analysis | |
1Department of Diagnostic Radiology, the first affiliated hospital of XI'AN jiaotong universityDepartment of Diagnostic Radiology, XI'AN, People's Republic of China |
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Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has been provided for noninvasive assessment of different grade of gliomas. But the diagnostic performance of this new approach was variant among the recent reports. This study included 10 DCE-MRI studies regarding to differentiating high grade gliomas (HGGs) from low grade gliomas (LGGs). The meta-analysis results demonstrated that parameters of DCE-MRI have high diagnostic performanc (Ktrans and Ve) in distinguishing HGGs from LGGs. DCE-MRI can be used as an important tool for the assessment of neovascular permeability and for the pre-operative grading of glioma. |
| 2223 | Imaging Characteristics According to the IDH Mutation and 1p19q Codeletion Status of Lower Grade Gliomas | |
1Yonsei University College of Medicine, Seoul, Korea, Republic of |
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Preoperative prediction of genotypic classification with MRI is useful because IDH mutation and 1p/19q codeletion status are important prognostic and predictive factors in lower-grade gliomas (WHO grade II and III). In this study we found that various preoperative imaging features including lobar/nonlobar or central location, enhancement characteristics, tumor margin, diffusion characteristics, ependymal/cortical involvement were different between IDH-wildtype and IDH-mutant group. Therefore preoperative MRI may be helpful to predict IDH mutation status in lower-grade gliomas. |
| 2224 | Development and validation of a MRI-based radiomics prognostic classifier in patients with primary glioblastoma multiforme | |
1Department of radiology, Guangzhou First People's Hospital, Guangzhou, People's Republic of China, 2Department of radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, People's Republic of China, 3GE Healthcare China, Guangzhou, People's Republic of China |
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Glioblastoma multiforme (GBM) is the most frequent and deadly type of primary malignant tumor in the central nervous system with a median survival range of only 9-15 months. We developed and validated a MRI-based radiomics classifier to predict overall survival(OS) in patients with newly diagnosed GBM. The results showed that a 7-radiomics classifier allows prediction of survival and stratification of patients with newly diagnosed GBM into a low- or high-risk group for OS. |
| 2225 | Tumor progression prediction in high grade glioma using multimodal image analysis and random forest machine learning | |
1German Cancer Consortium (DKTK), Heidelberg, Germany, 2Translational Radiation Oncology, National Center for Tumor Diseases (NCT), German Cancer Research Center (DKFZ), Heidelberg, Germany, 3Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany, 4Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany |
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Tumor delineation in radiotherapy planning of high grade glioma is challenging due to infiltrative growth patterns and physiological tumor heterogeneity. We used random forest machine learning to classify tissue types and predict tumor progression based on parameters derived from multi-modal functional and metabolic imaging. In an integrative approach, eight patients with recurrent high grade glioma were investigated retrospectively, and the resulting predicted tumor volumes were compared to standard T1 weighted contrast-enhanced MRI based segmentations. Predictions of tumor tissue could identify original tumor volumes well and yielded promising results with respect to tumor progression in terms of sensitivity and specificity. |
| 2226 | Molecular imaging of pediatric cerebellar tumors using endogenous protein-based amide proton transfer MR imaging at 3 Tesla | |
1Department of Radiology, Beijing Children’s Hospital, Capital Medical University, Beijing, People's Republic of China, 2Department of Radiology, Johns Hopkins University, MD, United States |
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Amide proton transfer (APT)-MRI is a chemical exchange saturation transfer (CEST) based approach in which the amide protons of endogenous proteins and peptides are irradiated to accomplish detection using the water signal. In this study, the APT approach was incorporated with standard brain MRI sequences and applied to children with cerebellar tumors at 3T. The initial results show that APT imaging can enhance the noninvasive identification of tissue heterogeneity and may be a biomarker of tumor grade in pediatric cerebellar tumors. |
| 2227 | Comparison of native longitudinal relaxation rate, apparent diffusion coefficient, and extravascular extracellular volume fraction in vestibular schwannoma in type 2 neurofibromatosis before and after antiangiogenic therapy | |
1Division of Informatics, Imaging and Data Sciences, The University of Manchester, Manchester, United Kingdom |
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The relationship between three functional parameters related to cell density, ADC, R1N, and ve, were examined in 12 patients with vestibular schwannomas pre- and post- anti-angiogenic therapy. 3D maps of R1N obtained with variable flip angle images, and ve derived from DCE-MRI were compared to 3D maps of ADC. The tumor mean values of ADC, R1N and ve showed correlation to each other before bevacizumab treatment. This correlation was lost after three-months of treatment. Both R1N and ADC displayed power in prediction of treatment. R1N showed more sensitive to anti-angiogenic therapy induced changes in VS than ADC or ve. |
| 2228 | Metabolic and functional MR imaging probe early response in glioblastoma patients treated with combination antiangiogenic-chemoradiation therapy | |
1Radiology, Massachusetts General Hospital, Boston, MA, United States |
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Precise assessment of treatment response in glioblastoma during combined antiangiogenic and chemoradiation remains a challenge. In particular, early detection of treatment response by standard anatomical imaging is confounded by pseudo-response or pseudo-progression. Metabolic changes probed by MRSI are more specific for tumor physiology and less confounded by changes in blood-brain barrier permeability. |
| 2229 | Assessment of therapeutic response in glioma with spillover-, MT- and T1-corrected amide proton transfer MR imaging | |
1Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China, 2Department of Neurosurgery, Cancer Center, Sun Yat-Sen University, Guangzhou, People's Republic of China |
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Amide proton transfer (APT) MR imaging has proved to be capable of detecting/grading brain tumors as well as assessing treatment response. Routinely used magnetization transfer (MT) asymmetry is contaminated with MT, nuclear overhauser effect (NOE) and T1 relaxation time of water. In this study, the dominant contributors of direct water saturation and MT to Z-spectrum were estimated from a sum of two Lorentzian functions, and APT was corrected with T1 scale and inverse Z-spectrum analysis. Results showed that the corrected APT can reliably depict glioma heterogeneity post-treatment, in accordance with H & E histological observations. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2230 | Longitudinal opto-pharmaco-fMRI of Selective Serotonin Reuptake Inhibition | |
1Institute for Biomedical Engineering, ETH and University of Zurich, Zürich, Switzerland, 2Preclinical Laboratory for Translational Research into Affective Disorders, DPPP, Psychiatric Hospital, University of Zurich, Zürich, Switzerland |
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The serotonergic system is a high-centrality node in the brain network implicated in affective disorders and their treatment. We use optogenetics, fMRI, and pharmacology to image serotonergic effects of antidepressant treatment in mice at the whole-brain level. We stimulate the ascending serotonergic system and perform functional imaging at multiple time points over the course of antidepressant (fluoxetine) treatment. We establish the feasibility of this paradigm, and report two trends in serotonergic kinetics: (a) increased serotonergic system signal transmission upon acute, but not chronic fluoxetine administration, (b) decreased serotonergic system excitability during the first phase of chronic fluoxetine administration. |
| 2231 | Graph-based network analysis of multi-echo resting-state fMRI data in people with high schizotypy | |
1Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom, 2Centre for Brain Health, University of British Columbia, BC, Canada |
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We applied graph theoretical network analysis on multi-echo resting-state fMRI data to examine whether healthy people with subclinical psychotic-like experiences (schizotypy) show abnormal functional brain topology compared to similar subjects without such experiences. While we did not observe significant between-group differences in any connectivity measure (Local and global efficiency, Modularity, and Small-worldness), within the schizotypy group we found that modularity and small-worldness were directly related to the severity of subclinical psychotic-like experiences. This demonstrates the feasibility of applying graph theory on multi-echo rs-fMRI in individuals with vulnerability for psychotic disorders and encourages the application of these methods in psychosis research. |
| 2232 | Cerebral blood flow measurements in patients with depression and comorbid hypertension in depression using 3D arterial spin labeling | |
1Radiology, Peking University Third Hospital, Beijing, People's Republic of China, 2GE Healthcare, MR Research China, Beijing, People's Republic of China |
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The aim of this study is to explore the potential differences of the quantitative CBF values among patients with depression, patients with hypertension and patients with comorbid hypertension in depression by using whole brain 3D PCASL and to investigate the correlation between CBF values and degrees of depression. The results indicate that CBF values decrease in frontal and parietal lobes in patients with comorbid hypertension in depression, whereas not in patients with depression or patients with hypertension, hypertension may play a synergistic action in the progress of depression. |
| 2233 | Homozygous loss of autism-risk gene CNTNAP2 results in reduced local and long-range prefrontal connectivity | |
1CIMeC, Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy, 2Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, Istituto Italiano di Tecnologia, Rovereto, Italy, 3Neurotoxicology and Neuroendocrinology Section, Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy, 4Neural Computation Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, Istituto Italiano di Tecnologia, Rovereto, Italy |
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Functional connectivity aberrancies as measured with resting-state fMRI (rsfMRI) have been consistently observed in the brains of autism spectrum disorders (ASD) patients. However, genetic and neurobiological underpinnings of these findings remain unclear. Here we used rsfMRI to show that homozygous mice lacking the strongly ASD-associated gene CNTNAP2 exhibit default-mode network connectivity alterations associated with reduced social investigation, a core “autism trait” in mice. These findings reveal a causal link between an ASD-associated mutation and functional connectivity aberrancies and suggest that homozygous loss-of-function mutations in CNTNAP2 may predispose to ASD through a selective dysregulation of functional coupling between integrative cortical areas. |
| 2234 | A preliminary study on amide proton transfer-weighted MR imaging in patients with obsessive-compulsive disorder | |
1Department of Radiology, Ruijin Hospital,Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China, 2Department of Functional Neurosurgery, Ruijin Hospital,Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China, 3Philips Healthcare, Shanghai, People's Republic of China, 4Philips Healthcare, Cleveland, OH, United States, 5Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 6Department of Psychiatry, Ruijin Hospital,Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China |
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The aim of this study is to evaluate the feasibility of amide proton transfer-weighted (APTW) MR imaging to detect cerebral abnormalities in patients with obsessive-compulsive disorder (OCD) and to explore its clinical utility. Five OCD patients and 9 normal healthy controls (NC) underwent APTW MR imaging. The magnetic resonance ratio asymmetry (MTRasym) values at 3.5ppm of anterior cingulate cortex (ACC) and thalamus were measured on axial APTW images. We found a trend of increased MTRasym(3.5ppm) or APTW within ACC in OCD patients compared with controls. No significant difference was found between groups in the MTRasym(3.5ppm) within bilateral thalamus. Our results suggest that APTW imaging maybe a promising approach to investigate pathological changes underlying OCD and may provide insights into clinical diagnosis of OCD. |
| 2235 | Pharmacological Inhibition of ERK Pathway Rescues Morpho-Anatomical Aberrancies Associated with 16p11.2 Chromosomal Deletion | |
1Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, Rovereto, Italy, 2CIMeC, Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy, 3Department of Neurosciences, Case Western Reserve University, Cleveland, OH, 4School of Biosciences, Cardiff University, Cardiff, United Kingdom |
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16p11.2 microdeletion is the most common copy number variation in autism. Recent studies revealed that mice harboring this microdeletion exhibit a paradoxical elevation of ERK activity, macroscale gray matter abnormalities and autistic-like behavioral deficits. By using high-resolution morpho-anatomical MRI, we show that prenatal treatment with an ERK pathway inhibitor rescues hippocampal and septal anatomical deficits in 16p11.2del mutants. The effect was associated with amelioration of anxiety behaviors. These results provide the first example of the rescue of developmental gray matter abnormalities in this mouse model, and support the translational use of structural MRI to assess putative therapeutic effects in autism. |
| 2236 | Aberrant striatal anatomy and gray matter connectivity networks in mice lacking autism-associated gene CNTNAP2. | |
1Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, Rovereto, Italy, 2CIMeC, Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy |
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Mice lacking CNTNAP2 exhibit robust autism-like behavioral traits, including stereotyped behaviors and excessive self-grooming. By using high resolution morpho-anatomical imaging in CNTNAP2 mutant mice, we identified marked volumetric alterations subcortical substrates implicated in ASD motor stereotypy, with a prominent involvement of the dorsal striatum. Importantly, we also show that in mutant mice, striatal but not cortical regions, exhibit dramatically expanded gray matter network extension, encompassing aberrant trophic interaction between limbic, subcortical and prefrontal regions. The observed striatal volumetric and gray matter network abnormalities serve as a plausible morpho-anatomical substrate for some of the stereotypy exhibited by CNTNAP2 mutant mice. |
| 2237 | Altered default mode network organization and functional connectivity in mice lacking autism-associated gene Shank3 | |
1Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, Rovereto, Italy, 2CIMeC, Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy |
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Mutations in autism-associated gene Shank3 have been associated to alterations in striatal function and core autistic behaviors. However, the neocortical substrates affected by Shank3 mutations remain undetermined. By using structural and functional MRI in Shank3B mutant mice, we identified key alterations in prefrontal and associative regions of the mouse default mode network (DMN). Specifically, we show that prefrontal and antero-posterior areas of the DMN present decreased gray matter volume, an effect associated with reduced local and long-range prefrontal functional connectivity. Our findings suggest that Shank3 mutations may predispose to autism via a selective trophic and functional downregulation of prefrontal areas. |
| 2238 | Different patterns of cortical matter changes in first episode bipolar manic adolescents: a surface-based structural MRI study with cluster analysis | |
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, People's Republic of China, 2Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati College of Medicine, Cincinnati, OH, United States |
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With an objective neuroimaging data-driven method using agglomerative hierarchical clustering analysis, two patterns of cortical matter changes among 58 first episode bipolar manic adolescents has been identified. And the clinical feature especially the intelligence quotient was corresponding to the subtyping among these patients. While the effect of medication and illness duration have been minimized, our findings provided new evidence indicating the existence of two neurobiologically distinct subgroups of patients with first episode bipolar mania, which may reflect qualitatively distinct genetic influences or neurodevelopmental alterations. |
| 2239 | Muscarinic receptor agonism prevents the functional connectivity aberrancies produced by the psychotogenic drug phencyclidine (PCP) | |
1Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ Unitn, Istituto Italiano di Tecnologia, Rovereto, Italy, 2CIMeC, Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy, 3Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States, 4Radiology and Imaging Sciences, Indiana University, Indianapolis, IN, United States |
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NMDA receptor antagonists like ketamine or phencyclidine (PCP) induce robust schizophrenia-like symptoms in rodents via glutamatergic disinhibition of cortico-limbo-thalamic substrates. We show that acute administration of PCP in the mouse elicits aberrant fronto-hippocampal and thalamo-cortical functional connectivity, an effect that can be prevented by pharmacological activation of M1/M4 muscarinic receptors. These changes highlight a previously unreported permissive contribution of muscarinic receptors on the aberrant connectional signatures produced by NMDAr antagonism which bear relevance for human connectivity mapping in hyperglutamatergic states and schizophrenia. |
| 2240 | Machine-learning classification of ADHD with biomarkers of cerebral cortical thickness: parcellation schemes, gender effects and feature selection | |
1National Taiwan University of Science and Technology, Taipei, Taiwan, 2National Sun Yat-sen University, Kaohsiung, Taiwan |
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In this study, we attempt to use machine-learning algorithms for ADHD classification with cerebral cortical thickness. We compared three cortical parcellation schemes and three different sets of features. The results supported the usage of Aparc and A2009s of FreeSurfer and suggested that recursive feature elimination effectively increased the predication accuracies. In addition, gender is an influential feature for the classification. |
| 2241 | Compulsivity as a Transdiagnostic Trait in Humans and Animal Models | |
1Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom, 2Department of Cognitive Neurscience, Radboud University Medical Center, Nijmegen, Netherlands, 3Center for Image Sciences, University Medical Center Utrecht, Utrecht, Netherlands, 4Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands, 5Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands, 6Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health Mannheim, Mannheim, Germany, 7NatBrainLab, Department of Forensics and Neurodevelopmental Sciences, Sackler Institute of Translational Neuroimaging, King's College London, London, United Kingdom |
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Obsessive-compulsive disorder (OCD) and diabetes mellitus type 2 (DM2) show compulsive behaviour1 and share genetic vulnerability2. Using Diffusion Tensor Imaging as a translational approach, we investigated differences in corpus callosum (CC) body white matter microstructure in a paediatric human OCD cohort and juvenile animal models for OCD and DM2. In all three groups, fractional anisotropy increased in the CC body compared to controls, which correlated with increasing compulsive behaviour. This was coupled with a decrease in CC mean diffusivity in the animal models. Our results underline the importance of compulsive behaviour as a possible trans-diagnostic trait across OCD and DM2. |
| 2242 | Remitted and non-remitted patients with schizophrenia show distinct patterns of white matter tract alterations | |
1Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan, 2Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan, 3Graduate Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan, 4Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan, 5Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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To investigate the relations between white matter tracts and treatment outcome, we performed diffusion spectrum imaging (DSI) and whole brain tract-based automatic analysis (TBAA) comparisons of the tract integrity over the whole brain. As compared with health controls, non-remitted patients showed reduced integrity in 7 fiber tract bundles, whereas remitted patients only showed 4 fiber tract bundles. When comparing with remitted patients, non-remitted patients showed reduced integrity in the same 7 fiber tract bundles as those found in comparison with healthy controls. Our results support that remitted and non-remitted patients had distinctly different severity of tract alterations. |
| 2243 | Altered amygdala function in nicotine-dependent individuals | |
1Radiology, The 2nd Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, People's Republic of China |
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To investigate the role of amygdala in nicotine dependence, we examined its structural and functional changes in smokers. Volume, amplitude of low frequency fluctuations (ALFF) and seed-based functional connectivity (FC) was used to detect differences. Results showed that although there was no significant volume change, right amygdala activity increased in smokers compared with nonsmokers. Furthermore, FC between the left amygdale and left orbit frontal cortex (OFC) increased while the right amygdale and bilateral OFC decreased in smokers. These results suggest that abnormal amygdala function may underlie the occurrence of nicotine dependence. |
| 2244 | Microstructure Alterations of Earthquake Survivors: A Longitudinal MR Diffusion Study | |
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, People's Republic of China |
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To reveal how traumatic events affect the integrity of brain microstructure in trauma-exposed non-PTSD people, we performed a longitudinal tract-based spatial statistics (TBSS) analysis in earthquake survivors using diffusion tensor imaging (DTI) data collected 25 days (TimePoint 1) and 2 years (TimePoint 2) after the Wenchuan earthquake. Our results showed that fractional anisotropy (FA) in several brain regions at TimePoint 2 were significantly increased compared with those at TimePoint 1. The increased FA in these regions may serve as the underlying neural substrates as brain recovered from the trauma. |
| 2245 | A Diffusion Tensor Imaging Study of White Matter Microstructure Concerning Suicidal Ideation in Major Depressive Disorder | |
1Radiology, Huaxi MR Research Center(HMRRC), Chengdu, People's Republic of China, 2Huaxi MR Research Center(HMRRC), Chengdu, People's Republic of China |
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Suicide is a serious public health problem, but little is known of microstructural abnormalities of white matter regarding suicidal ideation (SI). Sixteen depressive patients with SI, 16 depressive patients without SI and 32 age- and gender-matched healthy controls received MRI scans on a 3T magnet. Whole-brain voxel-based analysis was used to compare fractional anisotropy (FA) across the three groups with threshold at p<0.005(uncorrected) at voxel level and 50 for cluster size with SPM8. The three groups had significant differences of FA in the left centrum semiovale (peak Z=4.64 at -30, -38, 34), right centrum semiovale (peak Z=3.54 at 32, -34, 32) and right splenium of corpus callosum (peak Z=4.64 at 4, -34, 12). The alterations of white matter tract indicate that white matter integrity, especially a “frontal-related WM disconnection” may underlie the pathophysiology of suicidal ideation in depression. |
| 2246 | Gray matter reduction is associated with poor treatment response in patients with schizophrenia: A voxel-based morphometry study with a strict control of multiple clinical variables | |
1Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan, 2Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan, 3Graduate Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan, 4Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan, 5Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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To investigate whether remitted and non-remitted patients with schizophrenia had distinctly different gray matter volumes, we used voxel-based morphometry (VBM) to analyze group difference by controlling all possible clinical variables. As compared with remitted patients, the non-remitted patients showed 10 brain areas with significantly decreased gray matter volume. Our results imply that remitted and non-remitted patients might have distinct patterns of gray matter reduction, and the characteristics of gray matter change might represent the structural correlate of treatment response in patients with schizophrenia. |
| 2247 | Repeated Binge Alcohol Intoxication Leads to Lower Choline-Containing Compound Signals in Rat Brain: An In Vivo Marker of Alcohol-Induced Neurobiological Abnormalities | |
1Brain and Mind Centre, University of Sydney, Sydney, Australia, 2Department of Radiological Science, Yonsei University, Wonju, Korea, Republic of, 3Ewha Brain Institute, Ewha Womans University, Seoul, Korea, Republic of, 4Department of Biomedical Engineering, The Catholic University of Korea College of Medicine, Seoul, Korea, Republic of, 5Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul, Korea, Republic of, 6Department of Radiation Oncology, University of Florida, Gainesville, FL, United States, 7Department of Radiation Oncology, Ajou University School of Medicine, Suwon, Korea, Republic of, 8MR Core Laboratory, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea, Republic of |
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Alcohol is the most commonly abused intoxicating substance among young and middle-aged adults, and ranks highly as a cause of disability and mortality. A pattern of heavy consumption, called binge drinking, leads to various psychiatric disorders. We used in vivo proton magnetic resonance spectroscopy (1H MRS) to quantitatively assess neurochemical responses in hippocampus in a rat model of repeated-binge alcohol (RBA) intoxication. We determined that choline-containing compound, gamma-aminobutyric acid, and total N-acetyl-aspartate (tNAA: N-acetyl-aspartate + N-acetyl-aspartyl-glutamate) signals were highly sensitive to binge alcohol intoxication, which provides insights into neurochemical alterations associated with alcohol abuse. |
| 2248 | Eigenvector centrality mapping evaluating disease progression in Parkinson disease ：a longitudinal study | |
12nd Affiliated Hospital, Zhejiang University School of Medicine, hangzhou, People's Republic of China |
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Studied longitudinally 21 PD patients using Eigenvector centrality mapping,discovered significantly decreased EC values in right postcentral gyrus, and increased EC values in right cerebellum, right supplementary motor area (right SMA) as compared to B group. right postcentral gyrus in F group is negativelycorrelatedwithhoehn and yahr staging( HY) stage (r =-0.48, p < 0.05). Variation of EC values (F group-B group) in right cerebellum is positively correlated with changeofUPDRS-III scores. The current study demonstrated that deterioration and compensation exists through different circuit along with PD progression. |
| 2249 | Cerebral perfusion in Schizophrenia: an Arterial Spin Labeling study | |
1Physics Department, University of Sao Paulo, Ribeirao Preto, Brazil, 2Department of Neuroscience and Behavioral Sciences, University of Sao Paulo, 3Department of Medical Clinic, University of Sao Paulo |
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Schizophrenia is a mental disorder with structural and functional alterations that are not completely comprehended. We used a pseudo-continuous ASL protocol to investigate changes in resting CBF in schizophrenic patients. In addition, quantitative T1 and Gray Matter Volume (GMV) were assessed. Decreased CBF, GMV, and T1 values were observed in schizophrenic patients compared with healthy controls in several brain regions consistent with patients’ symptoms, such as deficits in planning solving and organizing thoughts. Therefore, motor, sensorial and cognitive impairments observed in schizophrenia may be related to CBF deficits and structural alterations in localized brain regions. |
| 2250 | Distortions in Dynamic Functional Connectivity in Autism Spectrum Disorders | |
1Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, United States, 2AU MRI Research Center, Department of Electrical and Computer Engineering, Auburn University, Auburn, AL, United States, 3Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States, 4Department of Psychology, Auburn University, Auburn, AL, United States, 5Alabama Advanced Imaging Consortium, Auburn University and University of Alabama Birmingham, Birmingham, AL, United States |
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Autism spectrum disorders (ASD) are neurodevelopmental disorders that have been associated with disruptions in brain connectivity. Using resting-state fMRI, we assessed the variability of whole-brain connectivity in individuals with ASD. Using a variable, sliding-window technique to calculate the variance of dynamic functional connectivity (vDFC), we show increased vDFC in ASD as compared to typically developing controls among prefrontal regions and within the salience network. Measures of vDFC were significantly correlated with measures of social functioning among all subjects. This work is significant as it suggests increased neural noise and disorganization in ASD. |
| 2251 | Characteristics of Cortical and Subcortical Abnormalities in Pediatric Attention Deficit Hyperactivity Disorder patients | |
1Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, People's Republic of China, 2Department of Psychiatry, West China Hospital of Sichuan University |
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The current study combine the analysis of the cortical measures and subcortical structures’ volume to evaluate the cerebral structure alterations in a relative large drug-naive ADHD sample. In addition, we also invest the anatomical–age correlation between two groups. Our findings (i) highlighted the crucial role of the frontostriatal circuits in the pathophysiology of ADHD, (ii) indicated the abnormality in neural development trajectory in ADHD. |
| 2252 | Pretreatment PET and MRI imaging markers of lithium treatment response/nonresponse in patients with bipolar depression | |
1Psychiatry, Stony Brook Medicine, Stony Brook, NY, United States, 2Radiology, Stony Brook Medicine, Stony Brook, NY, United States, 3Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States, 4Neurobiology & Behavior, Stony Brook University, Stony Brook, NY, United States |
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Bipolar disorder is one of the most prevalent psychiatric diseases in developed countries, and virtually all major psychiatric associations recommend lithium as the first line therapy for bipolar patients in the depressive phase of the illness, despite relatively low response rate for the drug and relatively high likelihood of side effects. However, no predictive criteria which indicate an individual patient’s responsiveness to lithium are employed clinically. In this work, we present preliminary findings demonstrating an association between baseline, multimodal neuroimaging measurements and lithium treatment outcome. |
| 2253 | Association between Major Depressive Disorder and the Functional Val158Met Polymorphism in Catechol-O-Methyltransferase as Assessed by Diffusion MRI | |
1Psychiatry, Stony Brook Medicine, Stony Brook, NY, United States, 2Radiology, Stony Brook Medicine, Stony Brook, NY, United States, 3Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States |
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Major Depressive Disorder is a debilitating illness that impacts 1 in 6 people in the United States during their lifetime. Particularly when monoamine levels are low, depression is associated with reduced volume in the front-limbic-striatum emotional processing network. Catechol-O-Methyltransferase (COMT) is responsible for most dopamine degradation in the frontal cortex. Guided by past literature, we examined the effect of COMT genotype on white matter integrity in the amygdala, hippocampus and parahippocampus in depressed patients along with healthy controls. Our results suggest the existence of sex-genotype interaction which is clinically relevant for women suffering from depression. |
| 2254 | Structural alterations in major depressive disorder and bipolar disorder-I: A meta-analysis of voxel-based morphometry study | |
1Huaxi MR Research Center (HMRRC), Chengdu, People's Republic of China |
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We used the SDM software to detect the similarities and differences of gray matter (GM) volume between MDD and BD, and found the significant decreases of GM in the bilateral insula and left inferior frontal gyrus (LIFG) characterized both MDD and BD-I, which may be related with the clinical symptoms including using few words and exhibiting poor choices of conversation topics during depressive state in both two affective disorders. AND the MDD patients had significantly lower GM volumes in the right superior temporal gyrus and right amygdala in comparison with BD-I patients, which indicated that reduced GM volume in the right angular gyrus specifically characterizes BD-I which may contribute to the manic symptom. |
| 2255 | It's all about the money: fMRI Reward Anticipation in Prodromal Psychotic Disorder. | |
1Psychiatrie & Psychologie, Maastricht University, Maastricht, Netherlands, 2Department of Psychosis Studies, King's College London, King's Health Partners, London, United Kingdom, 3Institute for Mental Health Care, Eindhoven, Netherlands |
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N/A |
| 2256 | Relationship Between DTI of the Brainstem Auditory Pathway and Latency of the Auditory M100 Response is Altered in Autism Spectrum Disorder | |
1Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States, 2Radiology, University of Pennsylvania, Philadelphia, PA, United States |
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Alterations to the auditory system’s structure and function may underlie the auditory processing and language disorders prevalent in autism spectrum disorder (ASD). This multimodal study compared DTI of the brainstem auditory pathway to magnetoencephalography (MEG) measures of auditory conduction velocity (M100 latency). The M100 latency measures the time between auditory stimulus and auditory cortex response. DTI and MEG were acquired from 29 children with ASD and 31 controls. Increased brainstem auditory pathway FA was predictive of faster signal conduction in controls (shorter M100 latency) (p<0.01), but not ASD. These results indicate ASD impacts the structure-function relationships throughout the auditory system. |
| 2257 | A study on the alteration of gray matter structure and the abnormality of iron metabolism in the post traumatic stress disorder | |
1radiology department, the Southwest Hospital of Third Military Medical University, chongqing, People's Republic of China |
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By using the VBM method，We found Neuronal damage may occurred in the early stage of the PTSD patients and dysfunction in orbitofrontal cortex, insula cortex which involving in the limbic system, and the precuneus involving in the DMN might play a critical role in pathophysiology of PTSD. By using the SPS rat model to mimic the PTSD disease, we also found iron accumulation in the prefrontal cortex, striatum, hippocampus in the SPS rat model. This study indicated that iron may be involved in the pathology of PTSD, and could be nominated as a novel molecule involved in the pathology of PTSD and provide a potential target for therapeutic intervention of PTSD. |
| 2258 | Gulf War Illness Patients Exhibit Impaired Connectivity in Multiple Brain Function Networks Consistent with Chronic Multi-Symptom Illness: A Resting State fMRI Study | |
1Department of Radiology & Imaging Sciences, Emory University, Atlanta, GA, United States, 2University of Texas Southwestern Medical Center, Dallas, TX, United States, 3University of Houston Clear-Lake, Houston, TX, United States |
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Around 200,000 veterans (up to 32% of those deployed) of the 1991 Gulf War (GW) suffer from GW illness (GWI), which is characterized by multiple deficits in cognitive, emotion, somatosensory and pain domains. In this study we examined 22 GWI patients and 30 age-matched controls with resting state fMRI (rsFMRI) in order to map impairments in brain function networks in GWI with graph theory based advanced network analysis methods. Results show widespread impairments in functional connectivity of cognition, affective, somatosensory and pain processing brain function networks in GWI consistent with multi-symptom nature of the illness. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2259 | Quantitative analysis of shape of eyes with high myopia by high-resolution three-dimensional magnetic resonance imaging | |
1Department of MRI, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China, 2MR Research China, GE Healthcare, Beijing, People's Republic of China, 3Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China |
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Myopia is a major cause of blindness worldwide. 134 patients with high myopia and 120 emmetropic volunteers were examined. All of the participants were scanned by high resolution 3D T2-weighted CUBE MRI sequence. This study is to evaluate the preoperative localization and postoperative assessment value of high-resolution 3D MRI for high myopia. It is shown that the axial length, horizontal length, vertical length and volume of the high myopia were significantly longer than those of the emmetropia. And high resolution 3D MRI could clearly demonstrate the position of staphylomas, superior rectus, inferior rectus, medial rectus, lateral rectus and optic nerve. |
| 2260 | High spatial resolution MRI-based three dimensional pathologic myopia eyes: a first step towards image-guided posterior sclera reinforcement | |
1Department of MRI, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China, 2Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China, 3MR Research China, GE Healthcare, Beijing, People's Republic of China |
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Eyes of 66 high myopia patients who were to undergo posterior scleral reinforcement surgery (PSR) were examined by high-resolution three dimension cube magnetic resonance imaging. It is demonstrated that 3D MRI technique is helpful to PSR preoperative localization by comparing the precision rate of buckling strips position in groups with and without 3D MRI-guided. The present study demonstrates that it is possible to not only check the eyeball shape of the pathologic myopia patients accurately, but also assistant the PSR surgery by using 3D MRI technique. |
| 2261 | Characterizing the Effect of Age on Measures of White Matter Integrity in the Optic Radiations of Children with and without Neurofibromatosis Type 1 | |
1Pediatrics, University Hospitals Rainbow Babies & Children, Cleveland, OH, United States, 2Pediatrics, The Children's Hospital of Philadelphia, 3Pediatric Neurology, The Children's Hospital of Philadelphia, 4Radiology, The Children's Hospital of Philadelphia |
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DTI measures in the optic radiations are a promising biomarker of vision in children with optic pathway gliomas, but normal values for fractional anisotropy (FA), radial diffusivity (RD), and mean diffusivity (MD) in young children have not been defined. In 40 children with neurofibromatosis type I (NF1) and 55 healthy control children between 0-14 years of age, we measured FA, RD and MD in the optic radiations. This study represents the first investigation of normal DTI measures in the optic radiations in young children and demonstrates an altered developmental trajectory in the optic radiations of children with NF1. |
| 2262 | Multi-parametric magnetic resonance imaging for differentiating benign from malignant orbital lymphoproliferative disorders | |
1Radiology, The First Aaffiliated Hospitla of Nanjing Medical University, Nanjing, People's Republic of China |
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We applied multi-parametric magnetic resonance (MR) imaging techniques, including conventional MR, diffusion weighted imaging (DWI) and dynamic contrast enhance MR imaging (DCE-MRI) in the evaluation of orbital lymphoproliferative disorders (OLPDs).These three imaging techniques evaluated the morphologic, diffusion and perfusion characteristic,respectively. We aim to determine the optimal combination of parameters derived from 3T multi-parametric MR imaging for differentiating malignant from benign OLPDs. |
| 2263 | Improved 2D navigated multishot DTI of the optic nerve with triggered eye fixation. | |
1Department of Radiology, Vanderbilt University Medical Center, Nashville, TN, United States, 2Vanderbilt University Institute of Imaging Science, 3Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 4Philips Electronics, Korea, Republic of |
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Optic Nerve DTI is of high interest in pathologies of the anterior visual pathway but high quality high-resolution diffusion MRI in the optic nerve is challenging because of involuntary eye motion. Vulnerability to motion induced phase errors is increased when multishot EPI (mshEPI) is used for achieving high imaging resolutions. In this abstract we present a triggered diffusion MRI approach with eye fixation that can significantly improve quality of optic nerve DTI, especially with mshEPI. |
| 2264
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Role of visual cortex during after and before critical developmental period in early blind and late blind: An fMRI study | |
1Department of NMR and MRI Facility, All India Institute of Medical Sciences, New Delhi, India, 2Dr. RP Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India |
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Visual cortex is preserved and is performing during non-visual stimuli showing development of specific compensatory mechanisms associated with visual area in blind subjects. Blind people process auditory language stimuli faster than sighted people. Some language functions suggest cortical reorganization in the blind subjects. |
| 2265 | A tract-based diffusion analysis in early and late blind subjects in the optic nerve and optic radiation | |
1Department of NMR and MRI Facility, All India Institute of Medical Sciences, New Delhi, India, 2Dr. RP Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India |
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Tractography Based Spatial statistics was carried out on the DTI and T1 data acquired in 20 late blind, 20 early blind and 15 healthy controls at 3 T. Early blind showed more white matter impairments as compared to the late blind suggesting plasticity in the early blind than in the late blind. The cross modal plastic changes in the late blind were not as significant as those in the early blind subjects, supporting the conception of prospective plasticity of brain may decrease with onset of age of blindness. |
| 2266 | Morphometric Analyses of Visual Cortex in Patients with Retinitis Pigmentosa | |
1Radiology, Zhengzhou University People's Hospital (Henan Provincial People's Hospital), Zhengzhou, People's Republic of China, 2Ophthalmology, Zhengzhou University People's Hospital (Henan Provincial People's Hospital), Zhengzhou, People's Republic of China, 3GE Healthcare MR Research China, People's Republic of China |
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Possible effects on the structures of visual cortex using high-resolution anatomical MRI have not been established so far. The aim of this study was to investigate volumetric alterations in visual cortex of RP patients using voxel based morphometry (VBM). Our results demonstrated that RP is associated with degeneration of structures in the visual cortex, and prevention of visual cortical degeneration may need to become a new therapeutic goal for RP patients, which may have significant meaning for clinical to guide RP patients' treatment in a more reasonable way in future. |
| 2267 | How does blindness onset impact on the structure of the optic radiation? | |
1CIMeC Center for Mind/Brain Sciences, Trento University, Trento, Italy, 2Institute of Psychology (IPSY) and of Neurosciences (IoNS); University of Louvain-la-Neuve; Belgium |
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The human brain is capable of massive reorganization in case of sensory deprivation. Blind studies show white and gray matter changes depending on blindness onset. However, the anatomical reorganization of the optical tract in blind is largely unknown. We investigated the changes in the optic radiation tract using diffusion-based tractography techniques in early and late blind subjects compared to age- and gender-matched healthy sighted controls. We found activity-dependent alterations of the optical radiation, demonstrating the importance of visual experience for the integrity of the tract. The characterization of such reorganization processes may have clinical value when assessing sight restoration possibilities. |
| 2268 | Ultra-high spatial resolution imaging in vivo of human retina at 3T | |
1Sino-Dutch Biomedical and Information Engineering School, Northeastern University, Shenyang, People's Republic of China, 2Department of Radiology, Wayne State University, Detroit, MI, United States, 3Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, People's Republic of China, 4Department of Biomedical Engineering, Wayne State University, Detroit, MI, United States, 5Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI, United States, 6Department of Ophthalmology, Wayne State University, Detroit, MI, United States, 7The MRI Institute for Biomedical Research, Detroit, United States |
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Imaging in vivo human retina remains a considerable challenge due to the thinness of the retina and eye motion. Here we provide proof-of-concept data supporting the use of an asymmetric gradient echo scan with TE to 5 ms and an effective resolution of 37 μm in the readout direction after partial Fourier reconstruction. To reduce motion, we employed a cued-blinking strategy and collected the data multiple times and averaged data that after co-registration. Preliminary results showed retina/choroid layer clearly with sufficient SNR to obtain a transretinal T1 map from vitreous body to sclera. |
| 2269 | Age-related MRI changes in the connective tissues of the eye | |
1Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, United States, 2Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States, 3Neuroimaging Laboratory, University of Pittsburgh, Pittsburgh, PA, United States |
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The structural organization and compositions of the corneoscleral shell determine the biomechanical behavior of the eye, and are important in aging and diseases such as glaucoma and myopia. However, characterizing the structure and composition of the eye and their changes with age or intraocular pressure remains a challenge. In this study, we showed that T2 mapping, magnetization transfer MRI and diffusion tensor MRI can be used to detect and differentiate age- and intraocular pressure-related changes in the porcine eyes. Multi-modal MRI may be useful for evaluating the biomechanical and (patho-)physiological mechanisms in the corneoscleral shell non-invasively and quantitatively. |
| 2270 | Permeability of the Blood-brain Barrier may Differentiate Neuromyelitis Optica Spectrum Disorder from Multiple Sclerosis | |
1Department of Radiology, Chinese PLA General Hospital, Beijing, People's Republic of China, 2GE healthcare China, Beijing, Beijing, People's Republic of China, 3GE healthcare China, Shanghai, Shanghai, People's Republic of China, 4Department of Neurology, Chinese PLA General Hospital, Beijing, People's Republic of China |
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The aim of our study was to characterize blood-brain barrier (BBB) permeability in neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) using dynamic contrast-enhanced MRI (DCE-MRI). Twenty-two NMOSD patients and twenty-three MS patients were enrolled. Significantly higher BBB permeability were found in lesions and normal appearing grey matter in MS group when compared with NMOSD but no differences were observed in corpus callosum. Hence BBB permeability, measured by DCE-MRI may be used for differential diagnosis between NMOSD and MS and may provide novel insights into the underlying pathological differences. |
| 2271 | Radiomics Features Extracted from MRI as Biomarkers for Neuromyelitis Optica Spectrum Disorder and Multiple Sclerosis Differentiation | |
1Department of Radiology, Chinese PLA General Hospital, Beijing, People's Republic of China, 2Chinese Academy of Sciences, Beijing, People's Republic of China, 3GE healthcare, Shanghai, People's Republic of China, 4Department of Neurology, Chinese PLA General Hospital, Beijing, People's Republic of China |
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The aim of our study was to ultilize combined radiomcis features extracted from T2-weighted MRI images as quantitative imaging biomarkers to differentiate neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS). Twenty-nine NMOSD patients and forty-five MS patients were enrolled. Our study showed 61 radiomics features and 8-feature-based radiomics signature were significantly different between NMOSD and MS. Therefore, radiomics may be an newly useful method which provides a promising non-invasive way of differentiating NMOSD and MS. |
| 2272 | The Role of the Human Visual Cortex in Assessment of the Long-term Durability of Retinal Gene Therapy in Follow-on RPE65 Clinical Trial Patients | |
1Center for Advanced Retinal and Ocular Therapeutics (CAROT), University of Pennsylvania, Philadelphia, PA, United States, 2F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, United States, 3Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, 4University of Pittsburgh, Pittsburgh, PA, United States, 5Center for Cellular and Molecular Therapeutics, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States, 6Westat Biostatistics and Data Management Core, University of Pennsylvania, Philadelphia, PA, United States |
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Leber’s congenital amaurosis (LCA) is a rare blinding disease with no cure. Recently, patients with LCA underwent retinal gene therapy and regained their vision to a great extent. We followed this group of LCA patients before and up to three years on an annual basis after gene therapy using fMRI to assess the feasibility and durability of retinal gene therapy over time and the role fMRI could play as an outcome measure for other future retinal interventions. |
| 2273 | The fate of auditory-visual cross modal plasticity after vision restoration through retinal gene therapy: Does auditory activity leave the visual cortex once vision returns? | |
1Center for Advanced Retinal and Ocular Therapeutics (CAROT), University of Pennsylvania, Philadelphia, PA, United States, 2F.M. Kirby Center for Molecular Ophthalmology, University of Pennsylvania, Philadelphia, PA, United States, 3Center for Cellular and Molecular Therapeutics, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States, 4Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States |
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Visual deprivation causes auditory-driven activity of occipital areas due to a process named auditory-visual |
| 2274 | Diffusion fMRI of mouse optic nerve with antidromic electrical stimulation | |
1Radiology, Washington University School of Medicine, St. Louis, MO, United States, 2The Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States, 3Biostatistics, Washington University School of Medicine, St. Louis, MO, United States, 4Neurology, The University of North Carolina in Chapel Hill, NC, United States, 5Neurology, Washington University School of Medicine, St. Louis, MO, United States, 6Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States |
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Previously, we have successfully employed diffusion fMRI (dfMRI) to assess impaired axonal function in experimental autoimmune encephalomyelitis (EAE) mice undergoing visual stimulation. However, the prior dfMRI experiments cannot resolve contributions from retinal dysfunction to the decreased dfMRI changes observed in EAE mice. To address this shortcoming, we implanted an MR-compatible tungsten electrode at lateral geniculate nucleus (LGN) to perform antidromic stimulation of optic nerves. We demonstrated perpendicular apparent diffusion coefficient decreased with antidromic electrical stimulation at LGN bypassing visual input through retina. |
| 2275 | fMRI of Visual Stimuli in a Tau Model of Alzheimer’s Disease | |
1University College London, London, United Kingdom, 2Eli Lilly and Company, Windlesham, United Kingdom, 3Eli Lilly and Company, Indianapolis, IN, United States |
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There is a need for non-invasive biomarkers that enable accurate tracking of early, pre-symptomatic phases of Alzheimer’s disease (AD). Previous fMRI studies have differentiated AD patients from healthy controls. However, it is unknown whether the accumulation of tau or amyloid pathology is driving the fMRI irregularity. This is the first study to investigate whether tau pathology alone can modulate task-based BOLD fMRI. We observed stronger BOLD responses to visual stimulation in lateral geniculate nucleus and superior colliculus in the tau cohort, mirroring observations in mild AD and MCI patients. |
| 2276 | Functionally Informed Fiber Tracking Using Combination of Diffusion and Functional MRI | |
1Department of Computer Science, Chengdu University of Information Technology, Chengdu, People's Republic of China, 2Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, 3Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 4Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, 5Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States |
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While fiber tractography using diffusion weighted MRI is a primary method that has achieved great success during the past decade, it however suffers from a number of inherent limitations. On the basis of the concept of a spatio-temporal correlation tensor we have introduced previously as a descriptor of the functional architecture in white matter, we propose in this study a novel algorithm for tractography by combing diffusion and functional MRI. Our experimental results show clear improvement of tractography accuracy for fiber tracts in the visual circuit, which demonstrates a great potential for reconstructing functional structure in brain whiter matter. |
| 2277 | Study of functional connectivity of default mode network and frontoparietal network in neuromyelitis optica | |
1Department of Radiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China |
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Neuromyelitis optica (NMO) is an inflammatory, demyelinating syndrome of the central nervous system characterized by severe attacks of optic neuritis and myelitis, but investigators in several studies observed abnormalities in deep gray matter. Functional MRI (fMRI) has the potential to further understanding of the neuropathologic mechanisms of NMO. In the present study, our aim was to investigate patients with NMO-related alterations of brain functional connectivity(FC) in resting state in default mode network (DMN) and frontoparietal network(FPN) using independent component analysis(ICA) and their correlations with clinical features. |
| 2278 | Reorganisation of cerebellar and dentate nucleus activity in multiple sclerosis subjects performing a complex visuomotor task: An event-related fMRI study | |
1UCL Institute of Neurology, Queen Square MS Centre, University College London, London, United Kingdom, 2Department of Diagnostic Radiology, Faculty of Applied Medical Science, KAU, Jeddah, Saudi Arabia, 3Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genoa, Genoa, Italy, 4Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy, 5Brain Connectivity Centre, C. Mondino National Neurological Institute, Pavia, Italy, 6Wellcome Centre for Imaging Neuroscience, University College London, London, United Kingdom, 7Brain MRI 3T Mondino Research Center, C. Mondino National Neurological Institute, Pavia, Italy |
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This study investigates the response to different grip force levels in the cerebellum and its dentate nucleus in MS. We found that cerebellar responses were functionally parcellated; with linear effects in the anterior cerebellum and complex nonlinear responses in the posterior cerebellum. This behaviour is consistent with healthy subjects (nonlinear responses in bilateral lobules V-VI and ipsilateral VIII), although MS subjects additionally show a strong linear response in lobule I-IV and nonlinear responses primarily localised in lobules V-VI. In the dentate nucleus, the motor portion in MS was silent as compared to the healthy subjects. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2279 | Fast and Robust Detection of Fetal Brain in MRI using Transfer Learning based FCN | |
1Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China, 2Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, Hong Kong, 3Shenzhen Research Institute,The Chinese University of Hong Kong, Shenzhen, People's Republic of China, 4Department of Radiology, Nanjing Drum Tower Hospital,The Affiliated Hospital of Nanjing University Medical School, Nanjing, People's Republic of China, 5Philips Healthcare, Hong Kong, 6Chow Yuk Ho Technology Center for Innovative Medicine, Hong Kong, 7Therese Pei Fong Chow Research Centre for Prevention of Dementia, 8Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong |
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In this work, we proposed a transfer learning based FCN method which can automatically detect the fetal brain in MRI. We used the off-the-shelf model weights trained on nature images to initialize a fully connected network (FCN), and then fine-tuned the model on the fetal MRIs. We tested our method on two datasets with different MRI sequences, and the results demonstrated that the proposed method is automatic, fast and robust for detection of fetal brain in MRI. |
| 2280 | Prenatal Maternal Depression and Anxiety Alter Hippocampal Development in Fetuses | |
1The Developing Brain Research Laboratory, Children’s National Health System, Washington, DC, United States |
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The hippocampus plays an important role in stress regulation. This study aims to investigate the relationship between prenatal maternal stress and fetal hippocampal volumetric growth using magnetic resonance imaging (MRI). Results suggest that maternal depression and anxiety are associated with smaller left hippocampal volumes in female fetuses in the third trimester of pregnancy. |
| 2281 | A pilot study of lateral ventricle volume from in utero foetal brain magnetic resonance imaging (MRI) | |
1State Key Laboratory of Bioelectronics, Southeast University, Nanjing, People's Republic of China, 2School of Biological Science and Medical Engineering, Southeast University, Nanjing, People's Republic of China, 3The First School of Clinical Medicine, Nanjing Medical University, Nanjing, People's Republic of China, 4Department of Radiology, Drum Tower Hospital of Nanjing University Medical School, Nanjing, People's Republic of China, 5Southeast University - Jiangsu Institute of Biomaterials and Medical Devices, Nanjing, People's Republic of China, 6Institute of Cancer and Genomic Science, University of Birmingham, United Kingdom |
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Neuroimaging for foetus brain is a challenging problem in which there are several issues to be solved. We proposed a general solution and finally reconstruct the lateral ventricle volume that is of great significance for clinical study. Firstly, slices were realigned to correct for the motion between acquisition of individual slices including transposition and rotation. Secondly, slices with motion artefacts were excluded and inconsistencies in intensity patterns resulting from the motion were estimated and corrected for. Thirdly, the structure of lateral ventricle was segmented via adaptive segmentation. Finally, the volume was reconstructed from irregularly sampled data. |
| 2282 | Correlation of fetal MRI with neurodevelopmental outcome in fetuses with ventriculomegaly | |
1Department of Radiology and Biomedical Imaging, University of California San Francisco, SAN FRANCISCO, CA, United States |
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Ventriculomegaly (VM) is the most common referred abnormality for fetal MRI and may be isolated or associated with additional abnormalities. We performed MR exams in 46 fetus diagnosed with isolated VM on ultrasound (US) and assessed neurodevelopmental outcome at 12 and 30 months with Bayley-III. Ventricle size (VS) measured by US and MRI and Bayley-III scores were analyzed using linear models. VS measured at older gestational age and longitudinal VS changes on MRI predicted outcome better than at younger age and on US. The presence of additional brain findings on fetal MRI significantly correlated with outcome and improved outcome predictability. |
| 2283 | Precise mapping of the developing somatosensory homunculus in the preterm human brain with fMRI and robotic tools | |
1Bioengineering, Imperial College London, London, United Kingdom, 2Centre for the Developing Brain, Kings College London, London, United Kingdom |
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The mature somatosensory cortex is known to be somatotopically organized, but it is not known when this functional organization emerges in human life. We aimed to map functional responses across the somatosensory cortex of preterm infants using fMRI and automated robotic tools. A preterm “homunculus” topology was identified with a spatially distinct distribution of functional responses following somatosensory stimulation delivered to the mouth, wrists and ankles. The results suggest that as seen in animal studies, the human preterm period is likely to be critical for the development of the somatosensory system. |
| 2284 | Heterogeneous increases of cortical mean kurtosis across brain regions during infancy | |
1Department of Radiology, Beijing Children’s Hospital, Capital Medical University, Beijing, People's Republic of China, 2Department of Radiology, Children’s Hospital of Philadelphia, Philadelphia, PA, United States, 3Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States |
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Brain development in the first few years of life is dramatic. The microstructural changes of infant grey matter measured by mean kurtosis, a non-Gaussian diffusion metric more sensitive to cortical microstructure than traditional diffusion metric, is not known. This study recruited 16 typical developing 3-32-months-old infants to investigate microstructural changes of the cerebral cortex by using Diffusion Kurtosis Imaging (DKI). Our results showed positive correlation between the mean kurtosis (MK) value and age. Differentiated age-dependent MK increases among different cortical regions suggest spatiotemporally heterogeneous pattern in cortical development. |
| 2285 | Relationship between Surface Area, Cortical Thickness and Folding in Infants | |
1Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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An intrinsic relationship between surface area, cortical thickness and folding |
| 2286 | Spherical Wavelets based Study of Multi-scale Cortical Folding in Infants | |
1Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2College of Biomedical Engineering & Instrument Science, Zhejiang University, Hangzhou, People's Republic of China, 3Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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Examining cortical folding development at various scales may help better understand brain cognition and motor functions. We propose a curvature-based multi-scale method using spherical wavelets to study the longitudinal changes of cortical folding during infancy. We applied our method on 219 longitudinal MR images from 73 healthy infants at 0, 1, and 2 years of age. We reveal scale-specific and region-specific developmental patterns of infant cortical folding. Specifically, at coarser levels, many primary folds flatten out; while at finer levels, the majority of the minor folds become more convoluted, providing new insights into early brain development. |
| 2287 | Lipid fractions as a marker for myelin maturation in the developing brain | |
1Centre for the Developing Brain, Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom |
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Myelination is an important aspect of brain development, but current myelin mapping techniques require extensive acquisition times and are therefore difficult to use routinely in neonates. In this study, we present results from a large cohort of neonates born preterm spanning a wide age range (26 to 125 weeks’ post-menstrual age) obtained using a recently proposed method that relies on existing routine data. Our results show good agreement with the expected spatial and temporal pattern of myelin formation over the age range studied, and may form the basis for future studies assessing myelin in the developing brain. |
| 2288 | Assessing white matter tract development in formula fed versus breastfed infants at 1 month and 3 months | |
1Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 2Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 3Boston Children’s Hospital, Boston, MA, United States, 4Beth Israel Deaconness, Boston, MA, United States |
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Diffusion Tensor Imaging and Tract-Based Spatial Statistic on FA, RD and AD were applied to investigate white matter development in formula fed infants and breast fed infants. Thirty-six infants (thirty breast fed and six formula fed) were scanned at 1 month and twenty-two (twelve breast fed and ten formula fed) at 3 months. Increased FA and decreased RD values were observed in breast fed infants at 1 month with differences becoming insignificant at 3 months. |
| 2289 | Non-negative matrix factorisation reveals developmental trajectories of structural subnetworks | |
1Developmental Imaging, Murdoch Children's Research Institute, Melbourne, Australia, 2Department of Paediatrics, University of Melbourne, Melbourne, Australia |
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We model the structural network architecture of the brain as a set of superposed subnetworks, or network components. We use non-negative matrix factorisation, an unsupervised and data-driven approach, to reliably identify separable subnetworks and track their development over the human lifespan. In the NKI-Rockland lifespan sample (n=196), we find evidence for an increased reliance on local communication between neighbouring regions, rather than through heavily-connected network hubs in older age. This method shows good potential for further exploration of the human structural connectome. |
| 2290 | Structural thalamocortical connectivity in the developing infant brain | |
1Centre for the Developing Brain, King's College London, London, United Kingdom, 2Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom |
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Thalamocortical development in early life is crucial for normal brain functioning and abnormalities to these networks are thought to underpin atypical neurodevelopment. However, to date examination of this system in the infant has been hampered by the lack of age-appropriate population atlases. In this study we circumvent this problem by applying independent component analysis to parcellate the thalamocortical projections and their underlying thalamic seed in 6-months-old infants using diffusion MRI. |
| 2291 | A Longitudinal Diffusion-Weighted Infant Brain Atlas with Spatio-Temporal Consistency | |
1Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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In this abstract, we introduce a longitudinal diffusion-weighted infant brain atlas. For construction of this longitudinal atlas, we collected the diffusion-weighted images of 36 subjects, scanned at 5 time points (at neonate, 3, 6, 9 and 12 months of age). Our method builds the atlas from the diffusion-weighted images without the need for any diffusion models. Also, our method, based on patch-based sparse representation, preserves more structural details with spatial-temporal consistency in the longitudinal atlas. Thus, when applied to quantitative analysis of infant brain images, more accuracy can be achieved. |
| 2292 | Longitudinally consistent infant cortical surface atlases and parcellations from birth to 6 years of age | |
1BRIC, UNC-Chapel Hill, Chapel Hill, NC, United States |
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For the first time, a longitudinally consistent infant cortical surface atlas with densely-sampled 11 time points (at 1, 3, 6, 9, 12, 18, 24, 36, 48, 60, and 72 months of age) is built for better exploring the dynamic and critical early brain development, based on 339 serial MRI scans from 50 healthy infants. The longitudinal consistency and unbiasedness are ensured by an advanced two-stage group-wise surface registration during the atlas construction. To equip parcellations for our atlases, both the FreeSurfer parcellation (for coarse parcellation) and HCP MMP parcellation (for fine-grained parcellation) are mapped onto our infant atlases. |
| 2293 | Multi-parametric brain morphometry using a big data approach | |
1Laboratory of Neuro Imaging, Keck School of Medicine of USC, Los Angeles, CA, United States, 2Laboratory of Neuro Imaging |
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Many studies have explored the relationship between neuroanatomical measures (such as cortical thickness or surface area) and cognition or health. Conventionally, generalized linear models are used to identify between-group differences within single measurements (e.g., regional cortical thickness), which ignores the possible interaction between neuroanatomical features. Incorporating a large number of regressors is not recommended in regression analyses, mainly due to the curse of dimensionality [1]. Multi-parametric classification approaches can be used to ameliorate the latter issue and to capture brain complexity [2]. The down side is that these approaches have less interpretability compared to regression techniques –because these techniques primarily focus on prediction accuracy rather than building an interpretable model. Here we present an approach that enables multi-parametric regression analysis by employing big data routine. |
| 2294 | Comparison of postnatal trajectory of neonatal white matter development between preterm and term neonates during the neonatal stage | |
1Department of Diagnostic Radiology, the first Affiliated Hospital of Xi'an Jiaotong University, Xi'an, People's Republic of China, 2Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, People's Republic of China, 3MR Research China, GE Healthcare, Beijing, People's Republic of China |
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Due to exposure to extrauterine environment, neonatal brain development is in totally different ways after birth, compared with the ‘protected’ gestation. However, little is known about the postnatal trajectory of neonatal brain development, especially for the differences between preterm and term neonates. This study aims to investigate the postnatal maturation of brain white matter (WM) during the neonatal stage and further provide comparison between preterm and term neonates. Our results suggest that during the neonatal stage, preterm neonates show weaker development capacity than term in optical and somatosensory functions, while present catching up maturation in motor function. |
| 2295 | Constrained spherical deconvolution has the potential to better characterize neuronal structure in Cerebral Palsy before and after therapy. | |
1Biomedical Engineering, University of Arizona, Tucson, AZ, United States, 2Phoenix Children's Hospital, Phoenix, AZ, United States, 3Pediatrics, University of Arizona, Tucson, AZ, United States |
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Cerebral Palsy is a nonprogressive condition that results in very heterogenous motor and other deficits that usually arises during the peripartum period. Many studies have tried to characterize changes in the brain of patients with cerebral palsy using fractional anisotropy and tractography based on diffusion tensor imaging, but few have utilized any of the more recent techniques, such as constrained spherical deconvolution, to more adequately account for complex fiber structures. These more recent techniques also offer more descriptive scalar measures of microstructure, such as apparent fiber density, that can be used to better characterize changes in neural structure. |
| 2296 | White Matter Abnormalities in Congenital Heart Disease Assessed Using Advanced Diffusion Imaging | |
1Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States, 2Boston Children's Hospital, Harvard Medical School, Boston, MA, United States, 3VA Healthcare, Boston, MA, United States |
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The study examined white matter (WM) abnormalities in neonates with Congenital Heart Disease (CHD) (19 CHD and 16 typically developing (TD) neonates). Gaussian mixture model showed that neonates with CHD have lower cellular volume and density in UF, SFOF, left IFOF, and CC. Fractional Anisotropy was lower in neonates with CHD in bilateral UF, CC, and left SLF. NODDI results indicated lower intracellular volume in the bilateral SFOF, and higher fiber orientation dispersion in the left CC and SLF in CHD. Our results demonstrate that significant WM abnormalities related to language areas are seen in neonates with CHD. |
| 2297 | BOLD MR Imaging of Placenta in Congenital Heart Disease | |
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2Radiology, Children's Hospital of Pittsburgh UPMC, Pittsburgh, PA, United States, 3Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, United States, 4Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh Medical Center, Pittsburgh, PA, United States, 5Radiology, Children's Hospital of Los Angeles, Los Angeles, CA, United States, 6Epidemiology, University of Pittsburgh, Pittsburgh, PA, United States |
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We examined whether features of placental BOLD MRI in underlying setting of fetal congenital heart disease (CHD) differ from those of healthy controls, and the imaging data correlated with first trimester maternal serum markers (PAPP-A, β-hCG) known to influence vasculogenesis/angiogenesis. We explored correlation between fetal brain resting stat networks and imaging and hormonal biomarkers of the placenta. We used temporal, spatial, and spatio-temporal to analyze the squared-root-mean variance and distribution differences in BOLD signal between CHD and controls. Difference in spatial and temporal BOLD signal variance is present in CHD pregnancies compared to healthy controls were observed. |
| 2298 | Multi-shell Multi-band Diffusion Imaging (MSMBDI) is more predictive of executive deficits in Preadolescents with Complex Congenital Heart Disease (CHD) compared to standard diffusion tensor imaging (DTI) | |
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2Radiology, Children's Hospital of Pittsburgh UPMC, Pittsburgh, PA, United States, 3Psychology, Carnegie Mellon University, Pittsburgh, PA, United States, 4Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, United States, 5Developmental Biology, University of Pittsburgh, Pittsburgh, PA, United States |
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We tested whether Multi-shell Multi-band Diffusion Imaging (MSMBDI) would be superior to standard DTI at delineating microstructural cortical association fiber abnormalities and predicting executive function preadolescents with complex congenital heart disease (CHD). Using both a hypothesis-driven approach (manual tractography) and a data-driven approach (q-space diffeomorphic reconstruction) we examined white matter tracts in correlation with NIH Toolbox and complementary battery of neuropsychological test. We show that MSMBDI – when compared to standard DTI – showed greater sensitivity towards white matter structure differences, superior at detecting microstructural differences in cortical association tracts in CHD compared to controls, and more predictive of executive deficits. |
| 2299 | Myelin-Water-Imaging in Hypomyelinating Leukodystrophies | |
1Department of Pediatric and Adolescent Medicine, Department of Pediatric and Adolescent Medicine, University Medical Center Goettingen, Goettingen, Germany, 2Department of Neuroradiology, University Medical Center Goettingen, Goettingen, Germany, 3Department of Neuroadiology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, 4Department of Cognitive Neurology, University Medical Center Goettingen, Goettingen, Germany, 5Department of Pediatrics and Adolescent Medicine, University Medical Center Goettingen, Goettingen, Germany, 6Advanced Baby Imaging Lab, Brown University School of Engineering, Providence, Providence, RI, United States, 7Department of Radiology, University of Colorado Denver, Denver, CO, United States |
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Emerging clinical research in hypomyelinating leukodystrophies (HLD) necessitates definition of surrogate markers as endpoints in possible clinical trials. Standardized assessment of myelination using myelin sensitive MRI is therefore highly desirable. Proposed protocols comprise DTI, MT-imaging and myelin water imaging employing the mcDESPOT sequence. We report first experiences applying mcDEPSOT in patients with cerebral folate deficiency. Myelin water fraction (MWF) allowed assessment of subtle gradual and regional changes with sufficient spatial resolution. The extent of the myelin deficit in diffuse hypomyelination can more reliably be evaluated using the MWF parameter. McDESPOT seems a feasible, system independent method to study pediatric HLD. |
| 2300 | Divergent trajectory of age-related cerebellar volume change in children with ataxia telangiectasia | |
1Radiological Sciences, University of Nottingham, Nottingham, United Kingdom, 2Radiotherapy and Radiation Oncology, University Hospital Carl Gustav Carus of the Technische Universität Dresden, Dresden, Germany, 3Paediatric Neurology, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom, 4Division of Child Health, University of Nottingham, Nottingham, United Kingdom |
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Cerebellar atrophy occurs in the inherited neurodegenerative syndrome Ataxia Telangiectasia (A-T) but the trajectory of cerebellar atrophy across childhood and its relationship to clinical status is unknown. We report cerebellar and fourth ventricular volumes (normalized to intracranial volume) from 24 children with A-T and 24 matched controls. Cerebellar volume declined linearly with increasing age in the A-T group with a divergent trajectory of age-related cerebellar volume change compared to normally-developing children. Fourth ventricular volume increased with age in children with A-T and correlated with clinical status, and may provide an imaging marker of neurological status in childhood A-T. |
| 2301 | The effect of the dopamine D4 receptor −616 C/G polymorphism on gray matter volume and functional connectivity in pediatric primary nocturnal enuresis patients | |
1Shengjing Hospital of China Medical University, Shenyang, People's Republic of China, 2Shengjing Hospital of China Medical University, 3Philips healthcare |
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The study assessed the effects of (DRD4) -616 (rs747302) gene variation on gray matter volume (GMV) and arousal from sleep (AS) scores in children that suffered from primary nocturnal enuresis (PNE) and normal controls and found that The −616 C/G SNP in the DRD4 promoter may affect the AS scores and GMV in the thalamus and pregenual ACC in PNE children. |
| 2302 | Altered regional brain activities in children with nonsyndromic cleft lip and/or palate (CL/P): a resting-state functional MRI study | |
1Imaging Center, Beijing Children's Hospital, Capital Medical University, Beijing, People's Republic of China, 2MR Research China,GE Healthcare, 3Beijing Stomatological Hospital, Capital Medical University |
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Resting state-fMRI has been widely used as an effective method to evaluate the of brain functional changes in physiological and pathological process. Altered regional brain activities, especially in verbal and cognitive areas were found in children with nonsyndromic CL/P using resting-state fMRI. It helps to understand the abnormality of functional architecture of CL/P which implies different structures and cognitive patterns in CL/P compared with normal development children. |
| 2303 | Study on the brains of perinatally HIV infected asymptomatic adolescents by intravoxel incoherent motion diffusion weighted imaging | |
1Department of Radiology, Remin Hospital of Wuhan University, Wuhan, People's Republic of China, 2Remin Hospital of Wuhan University, wuhan, People's Republic of China, 3Zhongnan Hospital of Wuhan University, People's Republic of China, 4GE healthcare China, Beijing, People's Republic of China |
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IVIM diffusion is applied to detect the changes in the brain of perinatally HIV-infected adolescents in our work. 18 children with HIV positive and 17 HIV negative children underwent MRI scan on a 3.0T whole body scanner including multi-b diffusion imaging. The IVIM parameters (D, D*and f ) were obtained by fitting using MITK software. Correlation of IVIM parameters and CD4+T cell counts, CD4/CD8 ratio were analyzed. D* value of caudate nucleus and frontal white matter decreased significantly in HIV positive children and the changes of D* were positively correlated with CD4+T cell counts and CD4/CD8 ratio. However，D and f were not statistically significant. IVIM improves on the detection brain damage in HIV infected asymptomatic adolescents as compared to conventional DWI. |
| 2304 | Microstructural heterogeneity of Superior longitudinal fasciculus (SLF-II) predicts impulsivity in healthy young girls | |
1Harvard Medical School, Boston, MA, United States, 2Brigham and Women's Hospital, Boston, MA, United States |
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Diffusion MRI (dMRI) is sensitive to microstructural arrangement of cells and axons in the brain. In this abstract, we analyzed dMRI data from 30 healthy children (14 girls, 13.9 ± 0.8 yrs, 16 boys, 13.4 ± 0.9 yrs). Advanced multi-tensor tractography was used to trace the SLF-II and heterogeneity in fractional anisotropy (HFA)4 (the standard deviation in FA) was computed in all subjects. Subjects were separated into two groups (males, females) and correlation between HFA and total Barratt Impulsivity Scores (BIS) was computed for each group. A statistically significant correlation was found between HFA in left SLF-II and BIS in girls but not in boys. The SLF-II has been known to be involved in spatial attention and executive control and higher heterogeneity in white matter integrity in SLF-II seems to be involved in impulsive/attentional network in young girls but not boys. |
| 2305 | DTI-based Connectome Analysis to Predict Outcome of Picture Exchange Communication System (PECS) in Young Children with Autistic Spectrum Disorders | |
1Pediatrics, Wayne State University, Detroit, MI, United States, 2Translational Imaging Lab, Children's Hospital of Michigan, Detroit, MI, United States |
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The aim of this study is to apply DTI-based connectome analysis to investigate the neural substrate and mechanism of picture exchange communication system (PECS) in young children with ASD. Seventeen non-verbal children with ASD who underwent PECS and 3T DTI (age: 3.05±0.82 years, 10 boys) were retrospectively selected for whole brain connectome analysis . Compared with 5 children who failed PECS (non-verbal after PECS), 12 children who succeeded PECS (verbal after PECS) showed significantly increased betweeness, local efficiency and nodal strength in anterior inferior occipital gyrus (p <0.01). Such increases may be an effective imaging marker to detect ASD children who will become verbal after PECS. |
| 2306 | Disrupted Brain Network Topology in Pediatric Tourette Syndrome: A Resting-State fMRI Study | |
1Department of Radiology, West China Second University Hospital, Sichuan University, Chengdu, People's Republic of China |
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Tourette syndrome is a neurobehavioral disorder characterized by motor and vocal tics beginning in childhood. Previous neuroimaging investigations suggested impaired cortico-striato-thalamo-cortical activity during motor control. We hypothesized that the small-world properties of functional connectomes would be abnormal in pediatric Tourette Syndrome patients. Compared with control subjects, the Tourette Syndrome patients showed altered quantitative values in the global properties, characterized by higher path length, higher normalized characteristic path length and lower global efficiency, implying a shift toward regular networks. The Tourette Syndrome group showed decreased nodal efficiency in the posterior part of left cingulum and right putamen comparing to the controls. |
| 2307 | Correlation Between Cerebral Blood Flow And Whole Brain Perfusion In Children Undergoing Deep Sedation. | |
1MRI Research, University Children Hospital, Zurcih, Switzerland, 2BioFlow, University Picardie Jules Verne, Amiens, France, 3MRI Research, University Children Hospital, Zurich, Switzerland, 4Anesthesia, University Children Hospital, Zurich, Switzerland, 5Radiology, University Children Hospital, Zurich, Switzerland |
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Anaesthetics such as those used for sedation in paediatric MRI affect cerebral blood flow and hemodynamics to varying degrees. This study examines the link between brain perfusion measured by arterial-spin-labelling and cerebral blood flow measured by phase-contrast MRI in 2 cohorts of children undergoing sedation either with propofol or a combination of propofol and ketamine. Significant correlations were observed between these 2 variables for both groups. |
| 2308 | MRI characteristics predicts clinical outcomes in severe hand, foot, and mouth disease：analysis of 412 children in China | |
1Guangdong Academy of Medical Sciences/Guangdong General Hospital, Guangzhou, People's Republic of China, 2Guangdong Academy of Medical Sciences/Guangdong General Hospital, People's Republic of China |
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Most severe hand, foot, and mouth disease(HFMD) are caused by EV71 infections, which can result in central nervous system complications. So magnetic resonance imaging (MRI) acquisition is important for the patients with EV71 infection to reveal the location of lesions and select the potential severe cases with poor prognosis. We aim to reviewed MRI characteristics of the severe HFMD, using a multivariate approach to compare the prognosis of different lesion sites based on a large cohort with follow-up. Our findings suggested lesions located in medulla oblongata (P<0.015)and spinal cord(P<0.001) on MRI associated with poor prognosis. |
| 2309 | Altered microstructural integrity of white matter tracts in children with aromatic L-amino acid decarboxylase deficiency | |
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, 3Department of Medical Genetics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan, 4Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan, 5Graduate Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan, 6Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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Aromatic L-amino acid decarboxylase (AADC) deficiency is an inherited disorder that impairs synthesis of dopamine and serotonin. To investigate whether the white matter tracts are impaired in children with AADC deficiency, diffusion tensor imaging data were obtained from 7 children with AADC deficiency and 7 matched controls. Fractional anisotropy (FA) of 76 white matter tracts was measured and compared between the two groups. Fiber tracts of dopaminergic and serotonergic systems, and those connecting regions responsible for executive functions or regulating motor functions showed lower FA in patients. Our findings are consistent with clinical manifestations and pathophysiology of AADC deficiency. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2310 | Understanding white matter pathology in ALS using a multimodal approach | |
1Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton, United Kingdom, 2Centre for Medical Image Computing and Computer Science, University College London, London, United Kingdom, 3Trafford Centre for Medical Research, Brighton and Sussex Medical School, Brighton, United Kingdom |
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Multimodal diffusion MRI and quantitative MT techniques were used to examine the nature of abnormalities in the corticospinal tracts (CSTs) of amyotrophic lateral sclerosis (ALS) patients. Our data show reductions in axonal volume fraction (AVF) located superiorly to reductions in myelin volume fraction (MVF). We also find extensive decreases in fiber volume fraction (FVF) throughout the entire CST, supporting the hypothesis of axonal loss as the primary pathological mechanism in ALS. |
| 2311 | DTI of the Sciatic Nerve in Patients with Charcot-Marie-Tooth Diseases | |
1Vanderbilt Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 2Neurology, Vanderbilt University, Nashville, TN, United States, 3Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States |
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This study examines the sensitivity of DTI metrics to proximal sciatic nerve pathology in a cohort of patients with Charcot-Marie-Tooth (CMT) diseases and matched controls, with the longer-term goal of developing objective biomarker of disease progression and treatment response. Prior studies have shown that DTI metrics can relate to disability in other neuropathies. Here we demonstrate that robust DTI can be performed in the proximal sciatic nerve of patients with CMT, and the resulting metrics are sensitive to myelin and/or axonal pathologies. Future studies will test if DTI measures predict disability in patients with CMT. |
| 2312 | Graph-based analysis of brain structural MRI data in Multiple System Atrophy | |
1Department of Biomedical and NeuroMotor Sciences, University of Bologna and Functional MR Unit, Policlinico S. Orsola - Malpighi, Bologna, Italy, Bologna, Italy, 2INFN-Bologna, Bologna, Italy, 3Department of Biomedical and NeuroMotor Sciences, University of Bologna and IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy, 4Department of Physics and Astronomy, Bologna, Italy, 5Centro Enrico Fermi, Roma, Italy |
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We investigated the differences in global and regional topological properties and the modular organization of brain networks derived from anatomical covariance of structural MRI between Multiple System Atrophy patients (subdivided in the variants MSA-C, MSA-P) and healthy controls (HC). No differences were found in global, local and small-worldness measures between MSA and HC or between MSA-C and MSA-P. The investigation of modular organization, which reflects differences in properties that underlie the functionality of the brain, has shown a segregation in a cortical-subcortical motor network in patient groups, which may underpin both the typical parkinsonian and cerebellar features of the disorder. |
| 2313 | Detection of subtle white matter alterations in migraine using diffusion kurtosis imaging | |
1Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan, 2Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, 3Department of Neurology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, 4Department of Healthcare Administration and Medical Informatics, Kaohsiung Medical University, Kaohsiung, Taiwan |
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Migraine subjects were demonstrated to exhibit white matter alterations detected by diffusion tensor imaging (DTI). Due to the Gaussian assumption of water distribution employed in DTI technique, the measured diffusivity may not be accurate and may hinder the detection of white matter alterations. Diffusion kurtosis imaging (DKI) was demonstrated to better characterize white matter alterations without Gaussian assumption and has not been utilized to detect white matter alterations in migraine subjects. This study performed DKI to detect microstructural white matter alterations and demonstrated that diffusion kurtosis parameters were more sensitive to subtle white matter alterations than diffusion tensor parameters. |
| 2314 | Comprehensive assessment of white matter alterations in Tourette syndrome using automatic whole-brain tract-specific analysis | |
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, 3Department of Pediatrics, National Taiwan University College of Medicine, Taipei, Taiwan, 4Graduate Institute of Brain and Mind Sciences, National Taiwan University College of Medicine, Taipei, Taiwan, 5Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan, 6Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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To identify microstructural alteration of white matter tracts in patients with Tourette syndrome (TS), diffusion spectrum imaging data were obtained from 14 patients and 14 matched controls. Whole-brain tract-based automatic analysis was employed to investigate the differences in white matter microstructures between the two groups. As compared with the controls, patients with TS showed altered tract integrity in callosal fibers, cingulum, thalamic radiations and corticospinal tracts. The altered white matter tracts account for clinical hallmarks and pathophysiology of TS, and might serve as structural correlates of TS. |
| 2315 | White matter microstructural changes in Rett syndrome: a whole brain tract-specific analysis | |
1National Taiwan University, Taipei, Taiwan, 2National Taiwan University, Taiwan, 3National Taiwan University Hospital, 4National Taiwan University |
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Rett syndrome (RTT) is characterized by trajectory changes in cognition and motor functions. To understand the disease-specific pathologic changes of each |
| 2316 | Quantitative evaluation of brain volume change after phthalate esters exposure using voxel-based morphometry | |
1Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, 2Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan, 3School of Medicine and Department of Pediatrics, Chung Shan Medical University and Hospital, Taichung, Taiwan, 4Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan, 5National Institute of Environmental Health Sciences, National Health Research Institutes, Miaoli, Taiwan |
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The products made by phthalate esters could be found everywhere. But there were only a few studies mentioned about the influence of phthalate esters exposure on brain volume. We used the voxel-based morphometry analysis to observe the correlation between the concentrations of maternal urine phthalate esters (MBP, MBzP, DEHP, MEHP, MEOHP) and children’s brain volume of gray and white matter. We found the negative correlation between the concentrations and the volume of frontal gyrus and cingulate gyrus. |
| 2317 | Network-dependent changes in functional connectivity at 7 tesla in young adults with Down syndrome | |
1Imaging Institute, The Cleveland Clinic, Cleveland, OH, United States, 2Case Western Reserve University, Cleveland, OH, United States, 3University Hospitals, Cleveland, OH, United States |
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This works uses 7 tesla MRI to assess resting state functional connectivity (rs-fMRI) in young adults with Down syndrome (DS). As compared to matched controls, individuals with DS show increased rs-fMRI in the default mode network, but decreased rs-fMRI in a network related to executive function. |
| 2318 | No Evidence of Increased Iron Accumulation in the Deep Gray Matter of Patients with Amyotrophic Lateral Sclerosis (ALS) | |
1Department of Neurology, Medical University of Graz, Graz, Austria, 2Division of Neuroradiology, Vascular and Interventional Radiology, Department of Radiology, Medical University of Graz, Graz, Austria |
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Iron accumulation in deep gray matter occurs during normal aging, but has also been observed in several neurodegenerative diseases. To investigate if this still holds true for ALS, we aimed at assessing the iron content in deep gray matter structures of 24 ALS patients with quantitative susceptibility mapping and its relation to 28 controls. We did not find any significant differences in iron levels between ALS patients and controls. This may indicate that iron accumulation in deep gray matter is a specific feature that is not associated with neurodegenerative diseases in general, but rather reflects more specific degenerative processes. |
| 2319 | Brain structural MRI and perfusion signature of ALS patients with different levels of cognitive deficits | |
1Radiology, Peking Union Medical College Hospital, Beijing, People's Republic of China, 2Neurology, Peking Union Medical College Hospital, Beijing, People's Republic of China, 3Ge Healthcare, MR Research China, Beijing, People's Republic of China |
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This study was done to explore potential brain changes in ALS patients with different levels of cognitive deficits with voxel-based analysis of CBF generated by pCASL and VBM. Significant GM loss and CBF decrease were demonstrated in the severe frontotemporal dementia group. No difference of GM or CBF was found between ALS-Cn and ALS-Ci. Differences between ALS-Ci and ALS-FTD overlapped with those found between ALS-Cn and ALS-FTD, and the changes were more widespread in the latter contrast. |
| 2320 | Mapping brain functional alterations in chemotherapy-treated breast cancer women using resting-state fMRI | |
1Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, 2School of Medicine, Chang Gung University, Taoyuan, Taiwan, 3Department of Psychiatry, Chang Gung Memorial Hospital, Chiayi, Taiwan, 4Breast Center, Taichung Tzu Chi Hospital, Taichung, Taiwan, 5Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan, 6Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan |
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Breast cancer (BC) is one of the common public health problems, and chemotherapy was the major treatment for breast cancer. The previous study showed abnormal brain function was associated with the late effects of chemotherapy (5 to 10 years). The purpose of our study was to evaluate the early effects of post-chemotherapy BC patients (in 6 months). We investigated the resting-state functional differences between post-chemotherapy BC patients and healthy control. Our results provided the evidence of brain functional changes in women with breast cancer and highlight the importance of the breast cancer-related chemotherapy. |
| 2321 | brain iron accumulation in amyotrophic lateral sclerosis - a quantitative susceptibility mapping study | |
1Radiology, the First Affilicated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, People's Republic of China, 2GE Healthcare, MR Research China, Beijing, People's Republic of China, 3School of Life Science and Technology, Xi'an Jiaontong University, the Key Laboratory of Biomedical Information Engeering, Ministry of Education, Xi'an, Shaanxi, People's Republic of China |
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Iron accumulation can induce a wide range of neuron disorders in central nerve system. Increased serum ferritin has been found to predict poor clinical outcome in ALS. We used quantitative susceptibility mapping to explore brain iron accumulation and theri clinical relevance. Increased iron level has been found in both cortical and subcortical motor related regions. The iron concentration in the primary motor cortex is responsible for deteriorated clinical syndrome, suggested its potential role for disease management. While increased iron concentration in the bilteral caudate contributed to impaired executive function, indicated network-based dysfunction for cognition decline in ALS. |
| 2322 | Regional Brain Myelin Changes in Patients with Heart Failure | |
1UCLA School of Nursing, University of California at Los Angeles, Los Angeles, CA, United States, 2Division of Cardiology, University of California at Los Angeles, Los Angeles, CA, United States, 3Neurobiology, University of California at Los Angeles, Los Angeles, CA, United States, 4Brain Research Institute, University of California at Los Angeles, Los Angeles, CA, United States, 5Anesthesiology, University of California at Los Angeles, Los Angeles, CA, United States, 6Radiological Sciences, University of California at Los Angeles, Los Angeles, CA, United States |
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Heart Failure (HF) patients show gray matter injury in multiple brain areas, based on various MRI techniques; such injury can accompany loss of subcortical and white matter myelin integrity. However, the extent of regional myelin changes in HF is unclear. We examined regional myelin integrity in HF patients, and found decreased values, likely resulting from hypoxic/ischemic processes, in critical autonomic, cognitive, respiratory, and mood control sites. These functions are deficient in the condition. Myelin mapping, based on simple-to-calculate ratios of T1- and T2-weighted images, is useful for evaluating regional myelin changes. |
| 2323 | Investigation of neuroinflammation and cognitive dysfunction following a major burn injury and critical care admission using advanced MR imaging | |
1Department of Imaging, Imperial College Healthcare NHS Trust, London, United Kingdom, 2Department of Bioengineering, Imperial College London, London, United Kingdom, 3Department of Medicine, Imperial College London, London, United Kingdom, 4Magill Department of Anaesthesia, Chelsea and Westminster Hospital NHS Foundation Trust, London, United Kingdom, 5Department of Academic Anaesthesia, Imperial College London, London, United Kingdom, 6Department of Psychology, Westminster University, London, United Kingdom, 7Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom |
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We used advanced MR imaging methods to investigate neurophysiological changes following major burns injury in a cohort of patients with reduced cognitive function compared to age and sex-matched controls. In this preliminary study, small regions of increased connectivity were observed in patients in two brain networks extracted from resting-state fMRI data using ICA. However, the significance of these results is unclear given the broad range of neurological functions implicated by the cognitive deficits. Furthermore, we found no significant difference between patients and controls for TBSS, volumetric analysis and MR spectroscopy. SWI indicated large areas of microbleeds in one patient. |
| 2324 | Region-specific damage in Progressive Supranuclear Palsy studied using multimodal quantitative MRI | |
1Neuroradiology department, APHP, Pitié Salpêtrière, Paris, France, 2UPMC Univ Paris 06, UMR S 1127, CNRS UMR 7225, ICM, F-75013, Sorbonne Universités, Paris, France, 3Centre de NeuroImagerie de Recherche – CENIR, ICM, Paris, France, 4Clinique des mouvements anormaux, Département des Maladies du Système Nerveux, Hôpital Pitié-Salpêtrière, APHP, Paris, France, 5Service des pathologies du Sommeil, Hôpital Pitié-Salpêtrière, APHP, Paris, France, 6NeuroSpin, CEA, Gif-Sur-Yvette, France |
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We used quantitative multimodal MRI to investigate the region-specific damage in progressive supranuclear palsy (PSP) in order to generate a precise model of neurodegeneration at various levels of the central nervous system, including brainstem nuclei, basal ganglia and cortex. PSP patients showed extensive volume decrease and microstructural diffusion changes in the brainstem and the basal ganglia in agreement with previous pathological studies. These results suggest the possibility of direct noninvasive assessment of brain damage in PSP not only in the basal ganglia and the cortex, as done previously, but also in small brainstem nuclei. |
| 2325 | Autosomal dominant cerebellar ataxia: The search for imaging biomarkers | |
1INSERM U 1127, CNRS UMR 7225, Sorbonne Universités, UPMC Univ Paris 06 UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France, 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 3Center for NeuroImaging Research, Institut du Cerveau et de la Moelle épinière, 75013 Paris, France |
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Spinocerebellar ataxias (SCAs) are neurodegenerative disorders characterized by predominant atrophy of the cerebellum and pons, with the main symptom being ataxia. There is currently no treatment for this disorder due to the lack of robust biomarkers to evaluate the disease progression. This study aimed to identify robust biomarkers for this disorder using a combination of magnetic resonance spectroscopy and imaging techniques. This study confirmed neurometabolic alterations in SCAs as well as microstructural modifications resulting from the disease. This study also showed that imaging biomarkers are more sensitive to disease progression than clinical scores. |
| 2326 | Dynamic Quantitative Imaging of Sodium During Migraine Onset and Propagation at 21.1 T | |
1Center for Interdiscplinary Magnetic Resonance, National High Magnetic Field Laboratory, Tallahassee, FL, United States, 2Chemical & Biomedical Engineering, Florida State University, Tallahassee, FL, United States, 3Molecular Neurology Program, Huntington Medical Research Institutes, Pasadena, CA, United States |
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The brain allocates >50% of its energy reserves to the regulation of sodium homeostasis, indicating the critical importance of sodium and its fluxes in normal brain and neurological disorders. The purpose of this study was to evaluate in vivo 23Na in the brain using a rat model of migraine induced by nitroglycerin injection. The ultra-high field of 21.1 T was employed to quantify alterations in bulk sodium during and following the onset of central sensitization related to migraine. Multi-slice 2D CSI of sodium were acquired longitudinally to identify localized increases in sodium concentrations during a 3-h period following sensitization induction. |
| 2327 | Endogenous assessment of hippocampus degeneration in end-stage renal disease with T1rho mapping and its comparison to voxel based measurement | |
1Radiology, Zhongda hospital, Medical school of Southeast university, Nanjing, People's Republic of China |
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It is reported that the brain always be an injured target organ in end-stage renal disease (ESRD) patients, a series of pathophysiologic changes easily make the iron accumulate in brain and accelerate the brain degeneration, which results in the brain cognitive function decline. T1rho relaxation time can reflect the changes of the macromolecular substance content and can be shorten by the Paramagnetic component, which makes it the ability to distinguish the healthy controls from ESRD patients. Voxel based measurement as a classical methods to verify the volume of each brain section, which can be also used to represent the structure of the brain. Combined with the results of neuropsylogical tests, T1rho mapping can better characterize the hippocampus in ESRD patients and the conclusions give a support for considering that the brain function changes earlier than structure changes. |
| 2328 | Evaluation of PROspective MOtion correction on high-resolution 3D-FLAIR acquisitions in epilepsy patients | |
1Translational Imaging Group, CMIC, University College London, London, United Kingdom, 2Epilepsy Society MRI Unit, Chalfont St Peter, United Kingdom, 3Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom, 4Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, Netherlands, 5Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, United Kingdom, 6Dementia Research Centre, UCL Institute of Neurology, London, United Kingdom |
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FLAIR is the single most sensitive MRI contrast to detect lesions underlying focal epilepsies but 3D sequences used to obtain isotropic high-resolution images are susceptible to motion. PROspective MOtion correction (PROMO) was applied to 3D-FLAIR scans in epilepsy patients to evaluate clinical benefit. Two radiologists reviewed 40 scans without and 80 with PROMO assessing six criteria on a seven-point Likert scale. PROMO scans can achieve near-identical image quality as nonPROMO scans, but intensity inhomogeneity was generally poor using PROMO. The percentage of scans with bad image quality was 4-fold lower with PROMO than without on the other five criteria. |
| 2329 | Brain iron accumulation in Wilson disease measured by QSM and MR relaxometry | |
1MR-Unit, Dept Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic, 2German Center for Neurodegenerative Diseases, Magdeburg, Germany, 3Institute of Clinical Biochemistry and Laboratory Diagnostics, Charles University in Prague, 1st Faculty of Medicine and General University Hospital, Prague, Czech Republic, 4Dept Pediatrics and Adolescent Medicine, Charles University in Prague, 1st Faculty of Medicine and General University Hospital, Prague, Czech Republic, 5Dept Biomedical Imaging and Image guided Therapy, Medical University of Vienna, Vienna, Austria, 64th Dept Internal Medicine, Charles University in Prague, 1st Faculty of Medicine and General University Hospital, Prague, Czech Republic, 7KlinMed, Prague, Czech Republic, 8Dept Neurology and Center of Clinical Neuroscience, Charles University in Prague, 1st Faculty of Medicine and General University Hospital, Prague, Czech Republic |
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Relaxometry and quantitative susceptibility mapping were used in patients with neurologic symptoms of Wilson disease (WD) that leads to copper metabolism disturbances and its gradual accumulation in liver and brain. These quantitative MR techniques revealed decreased T2 relaxation times in the basal ganglia, higher susceptibility in the deep gray matter nuclei and no T1 changes. It indicates presence of insoluble para- or superparamagnetic compounds, presumably in a form of hemosiderin. These deposits appear to be not related to the ceruloplasmin oxidase activity nor with the severity of neurological symptoms. |
| 2330 | A Chemical Warfare Nerve Agent Causes Regional Changes in Brain T2—Consistent with Localized Edema | |
1Radiology, University of Calgary, Calgary, AB, Canada, 2National Defence, Defence Research And Development Canada, Suffield, AB, Canada |
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Chemical Warfare Nerve Agents ( |
| 2331 | Enhanced visualization of lesions in focal cortical dysplasia using the fluid and white-matter suppression (FLAWS) sequence | |
1Radiology, Xuanwu Hospital Capital Medical University, Beijing, People's Republic of China, 2MR Collaborations NE Asia, Siemens Healthcare, Beijing, People's Republic of China, 3Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 4Radiology, University Hospital (CHUV), Lausanne, Switzerland, 5LTS5, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland |
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High contrast in the lesion area is one of the most important prognostic factors for focal cortical dysplasia (FCD). The fluid and white-matter suppression (FLAWS) sequence provides two sets of 3D contrasts from one acquisition: one nulls the white-matter signal, the other nulls the cerebral spinal fluid signal. A new image (the FLAWS contrast) calculated from these two images may enhance the visualization of FCD lesion features, specifically the blurred grey-white matter interface and the transmantle sign. In this study, we assessed the ability of FLAWS to visualize FCD lesions. Our results demonstrate that FLAWS is sensitive to lesional tissue, especially the transmantle sign, providing additional value in MR-based FCD diagnostics. |
| 2332 | Altered whole brain connectivity related to time of drug usage in methamphetamine abusers | |
1Department of Radiology, Huaxi MR Research Center, Chengdu, People's Republic of China, 2Department of Psychiatry, West China Hospital, Sichuan University, Chengdu, People's Republic of China |
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The current study aimed to use a novel graph-theory approach known as degree centrality to help diagnose methamphetamine abusers. Our findings identified increased degree centrality in right middle frontal gyrus, right inferior frontal gyrus and anterior cingulate cortex and degree centrality reductions were revealed in right superior parietal lobe and bilateral lingual gyrus. Additionally, decreased degree centrality of right lingual gyrus negatively correlated with the duration of methamphetamine abuse. Meanwhile, decreased degree centrality of right lingual gyrus might be a predictor of methamphetamine abuse duration with an acceptable diagnostic accuracy of 71%. |
| 2333 | Could ASL separate MCS from VS in patients with DOC？ | |
1Radiology Dept., PLA Army General Hospital, Beijing, People's Republic of China, 2Neurosurgery Dept., PLA Army General Hospital, Beijing, People's Republic of China, 3Academy of Military Medical Sciences, Beijing, People's Republic of China |
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This study used 3D pseudo-continuous arterial spin labeling (pcASL) to compare cerebral blood flow (CBF) patterns in minimally conscious state (MCS) patients with those in vegetative state (VS) ones. The results identified different CBF patterns within specific brain regions in VS patients compared with MCS. ASL may serve as an adjunctive method to separate MCS from VS in DOC patients, and could be used in longitudinal assessments of patients with severe brain injuries. |
| 2334 | The effect of Amantadine on Persistent Vegetative State patients: an fMRI pilot study | |
1Radiology & Psychiatry, Ichan School of Medicine at Mount Sinai, New York, NY, United States, 2Rehabilitation medicine, The First Hospital of Jilin University, Changchun, People's Republic of China, 3Radiology, The First Hospital of Jilin University, 4Radiology, Icahn School of Medicine at Mount Sinai, 5Icahn School of Medicine at Mount Sinai, 6Rehabilitation Medicine, The First Hospital of Jilin University |
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Task based fMRI and resting state scans were acquired on Persistent Vegetative State Patients before and after the administration of Amandatine. Significant clusters of activation was detected post treatment. |
| 2335 | Attenuated low frequency oscillations in focal cortical dysplasia | |
1Departments of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, Netherlands, 2Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands |
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The objective was to assess the time-signature of spontaneous BOLD brain fluctuations in patients with focal cortical dysplasia (FCD) and to compare these with other regions and healthy controls. Whole cerebrum resting-state functional MRI time-series were analyzed using three different BOLD measures: wavelet entropy, regional homogeneity and fractional amplitude of low frequency fluctuations. All the three BOLD measures indicated attenuated low frequency oscillations in FCD lesions compared to controls. Also abnormal BOLD activity was found in the proximal and contralateral region, which can complicate the interpretation on what regions are functionally normal, functionally connected or abnormal in patients with FCD. |
| 2336 | Wired minds: The neural underpinning of the entrepreneurial brain | |
1Mint Labs, Barcelona, Spain, 2IDIBAPS, Hospital Clinic, Barcelona, Spain, 3Department of Personality, Universitat Barcelona, Barcelona, Spain |
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Very little is known |
| 2337 | Cortical thickness in relation to m.3243A>G mutation load in MELAS syndrome | |
1Department of Cognitive Neuroscience, Maastricht University, Maastricht, Netherlands, 2Department of Radiology, Maastricht University Medical Centre, Maastricht, Netherlands, 3Department of Genetics and Cell Biology, Maastricht University, Maastricht, Netherlands, 4Department of Neurology, Erasmus MC, Rotterdam, Netherlands |
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The m.3242A>G mitochondrial mutation is known to cause the MELAS syndrome. A group of MELAS patients was scanned using multi-parameter quantitative 7T MRI to assess brain changes related to mutation load and disease duration. Here, we focused on cortical thickness differences between control subjects and MELAS patients and within patients as a function of mutation load. MELAS patients were characterized by a reduced cortical thickness compared to control subjects in several regions. Within these regions, cortical thickness decreases with increasing mutation load for the fusiform and planum temporal gyri, which are involved in visual working memory and auditory processing, respectively. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2338 | Age-related change of the whole brain T1 relaxation time: voxel-wise study with MP2RAGE | |
1Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan |
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Correlation was investigated between normal aging and T1 relaxation time in the deep gray matter with MP2RAGE sequence using voxel-based analysis (VBA) and regions-of-interest (ROIs) focusing on the deep gray matter (GM). Seventy healthy subjects were included. In VBA, linear correlation was explored, whereas second order regression was added in ROI analysis. The results showed relationship that varied among deep GM structures. Those findings will shed light on further investigation of T1 relaxation time in patient groups. |
| 2339 | Factors influencing the detection of age-dependent variations of cortical myelin by MP2RAGE at 9.4T. | |
1Biomedical Magnetic Resonance, University Hospital Tübingen, Tübingen, Germany, 2High Field Magnetic Resonance, Max-Planck Institute for Biological Cybernetics, Tübingen, Germany, 33General Psychiatry&Psychotherapy, University Hospital Tübingen, Tübingen, Germany, 4University Ulm, Germany |
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Detection of subtle variation of the myeloarchitecture within the cerebral cortex may be feasibile with high-field mapping of the longitudinal relaxation time. However, besides myelin other factors like iron or variation of the grey matter volume may impact this MR parameter. In the present work we propose a model that includes and quantifies these factors. We found a regionally dependent, continuous increase from early adulthood into the middle ages that tentatively can be assigned to myelin. |
| 2340 | Individual Evaluation System Development Concept Research for Personalized Brain Aging Process Using Machine Learning | |
1Radiology, Kyung Hee University Hospital, Seoul, Korea, Republic of |
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White matter hyperintensities (WMH) is one of the important characteristics of cerebral small vessel disease (cSVD). To diagnosis individual WMH evaluation method and investigate the degree of WMH form using MR image, we proposed that machine learning based on WMH group classification and individual diagnosis system. |
| 2341 | Neuromelanin-weighted MRI in revealing human development and age-related changes in locus coeruleus and substantial nigra | |
11Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Queen’s Medical Centre, University of Nottingham, Nottingham, United Kingdom, 2Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom, 3Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, United Kingdom, 4Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Queen’s Medical Centre;, University of Nottingham, Nottingham, United Kingdom |
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Rapid neuromelanin-weighted MR imaging sequence was performed to noninvasively inspect the physiological changes of substantial nigra and Locus ceruleus across a wide range of age in healthy subjects using neuromelanin-sensitive MRI for the first time. |
| 2342 | Characterizing brain iron deposition in patients with subcortical vascular mild cognitive impairment using quantitative susceptibility mapping: A potential biomarker | |
1Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China, 2Ge Applied Science Laboratory, GE Healthcare, Shanghai, People's Republic of China, 3Department of Neurology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China |
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The presence and pattern of iron accumulation in subcortical vascular mild cognitive impairment (svMCI) or their effects on cognition has rarely been investigated. The purposes of the present study were to investigate brain iron deposition in deep gray matter nuclei in svMCI patients using quantitative susceptibility mapping (QSM) and its correlation with the severity of cognitive impairment. Susceptibility values were found to be elevated within bilateral hippocampus and right putamen in svMCI group compared with controls, which were related to cognitive measurements. Our result suggests that brain iron deposition which relation to cognition indicates the clinical relevance of the biomarker. |
| 2343 | Early detection of Alzheimer's Disease using a combined index of gray matter texture | |
1Brain & Cognitive Sciences, Seoul National University, Seoul, Korea, Republic of, 2Asan Medical Center, Seoul, Korea, Republic of, 3Department of Neuropsychiatry, Seoul National University Bundang Hospital, Seoul, Korea, Republic of, 4College of Medicine, Seoul National University, Seoul, Korea, Republic of |
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Development of sensitive markers that can detect Alzheimer’s Disease at its pre-dementia stages is of critical importance. We hypothesized that altered cytoarchitecture caused by AD pathology would lead to a subtle altered pattern of voxel intensities on MRI which could be detected by texture analysis. In a training set of 111 AD and 141 normal controls, we extracted a set of texture features from core regions affected by pathology – precuneus, posterior cingulate cortex, hippocampus – that could efficiently discriminate between the two groups(AUC=0.875, p<0.001) as well as predict MCI/AD conversion from the normal stage (AUC=0.716, p=0.031). |
| 2344 | The profile pattern of white matter hyperintensities (WMH) has a primary role on discriminating the cognitive function. | |
1brain & cognitive sciences, Seoul national university, Seoul, Korea, Republic of, 2Psychiatry, Seoul National University Budang Hospital, Budang, Korea, Republic of, 3Asan Medical Center, Korea, Republic of |
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The areas in cerebral white matter appearing hyperintense on T2-weighted and fluid-attenuated inverse recovery (FLAIR) MRI are commonly referred to as white matter lesions (WMLs). Diverse scores and rating systems have been used for evaluating WMLs. However, these visual rating scales are still qualitative and subjective, leading to low reliability and reproducibility. The purpose of this study is to investigate the relation between cognitive functions and WMLs clustered by their profiles of distance from the ventricle, establishing the quantitative and objective evaluation of WMLs. |
| 2345 | Diffusion microstructural imaging of reversible and irreversible changes within the corticospinal tract in idiopathic normal pressure hydrocephalus | |
1Department of Radiology, the University of Tokyo, Tokyo, Japan, 2Department of Radiology, Juntendo University School of Medicine, Tokyo, Japan, 3Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan, 4Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan |
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Microstructural changes of the corticospinal tract (CST) in idiopathic normal pressure hydrocephalus (iNPH) before and after CSF shunt surgery were studied using NODDI and WMTI. Pathological increase of orientational coherence and its postoperative normalization were shown, indicating axon stretching and its recovery. To the contrary, decrease of axon density was present in iNPH and remained after the surgery. Simulation using undulating cylinder model demonstrated both NODDI and WMTI can separate the effects from axon density and undulation. These results suggest possibilities of diffusion MRI to distinguish between reversible and irreversible microstructural changes in iNPH, and raise expectation for prediction of treatment outcome. |
| 2346 | Global Change of Intrinsic Functional Networks as an Imaging biomarker of Alzheimer’s disease | |
1Translational Imaging Research Center, College of Medicine, Taipei Medical University, Taipei, Taiwan, 2Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, 3Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan, 4Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan, 5Department of Medical Research, Taipei Medical University Hospital, Taipei, Taiwan, 6School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, Taiwan |
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The change of whole-brain connectivity during resting state can be a reliable feature in discriminating patients with Alzheimer’s disease (AD) from patients with mild cognitive impairment and cognitively healthy elders. Significant correlations between resting-state functional connectivity and cognitive decline measured by Mini-Mental State Examination (MMSE) were further identified. |
| 2347 | Demyelination in Mild Cognitive Impairment | |
1National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD, United States |
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An emerging hypothesis suggests that the underlying pathophysiology of mild cognitive impairment (MCI) involves alterations in brain myelination. These alterations may represent an important correlate of dementia. Several studies have examined this correlation; however, these earlier analyses were performed using non-myelin-specific methods such as relaxation times, magnetization transfer and diffusion. This greatly complicates the interpretation of such imaging results in terms of myelin content. Our results show direct evidence of MWF alterations and loss in MCI using a direct measure of myelin-bound water. |
| 2348 | No significant increase of magnetic susceptibility found in subcortical gray matter of patients with Alzheimer’s Disease | |
1Philips Research Europe, Hamburg, Germany, 2University of Sheffield |
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Quantitative Susceptibility Mapping (QSM) and volumetry are 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. For comparison QSM is also performed using L1-MEDI from the MEDI-Toolbox. The tissue magnetic susceptibility shows no significant difference between the Alzheimer group compared to the healthy control group. In contrast, the normalized volume of segmented gray-matter regions is significantly reduced in AD patients. |
| 2349 | Using Calibrated Proton Density Imaging to Measure Blood-Brain Partition Coefficient in Aging and Alzheimer's Disease Mice | |
1Biomedical Engineering, University of Kentucky, Lexington, KY, United States, 2Biomedical Engineering, University of Kentucky, KY, United States, 3Magnetic Resonance Imaging and Spectroscopy Center, 4Sanders-Brown Center on Aging, University of Kentucky, KY, United States, 5Molecular and Biomedical Pharmacology, University of Kentucky, 6Pharmacology and Nutritional Sciences, University of Kentucky |
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In this study we determine the blood-brain partition coefficient (BBPC) in aging C57Bl6/N mice and the transgenic 129S6/Tg2576 mouse model of Alzheimer’s disease using a calibrated proton density imaging approach. Aging mice demonstrate a 5.5% reduction in BBPC compared to young mice (0.94±0.04 mL/g vs 0.99±0.04 mL/g, p = 0.02), however Tg2576+ mice preliminarily demonstrate an elevated BBPC compared to wild-type controls (01.03±0.04 mL/g vs 1.00±0.05 mL/g). These high quality BBPC maps acquired much faster than previously reported could potentially be used to correct cerebral blood flow measurements derived from arterial spin labeling. |
| 2350 | Neuroanatomical substrates that account for worsening performance in the Clock-Drawing Test in mild cognitive impairment | |
1Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan, 3F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States |
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The Clock-Drawing Test (CDT) is used to screen and select cognitively impaired individuals for further evaluation. For the clinical interpretation of the CDT, an understanding of the neuroanatomical substrates that account for a decline in the CDT score is essential. We investigated the relationships between regional volume loss and a decline in the CDT score in two years. Atrophy in the left prefrontal and middle-occipital gyri was correlated with a decline in the CDT score. The result validated the use of the CDT, combined with memory tests that evaluate parieto-temporal functions, as part of an overall cognitive screening. |
| 2351 | Deep Cross-Modal Feature Learning and Fusion for Early Dementia Diagnosis | |
1Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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Studies have shown that neuroimaging data (e.g., MRI, PET) and genetic data (e.g., SNP) are associated with the Alzheimer’s Disease (AD). However, to achieve a more accurate AD diagnosis model using these data is challenging, as these data are heterogeneous and high-dimensional. Thus, we first used region-of-interest based features and deep feature learning to reduce the dimension of the neuroimaging and SNP data, respectively. Then we proposed a deep cross-modal feature learning and fusion framework to fuse the high-level features of these data. Experimental results show that our method using MRI+PET+SNP data outperforms other comparison methods. |
| 2352 | Use of population-specific atlases for brain morphometry: benefits in Alzheimer’s Disease diagnosis decision support for Chinese patients | |
1Advanced Clinical Imaging Technology, Siemens Healthcare HC CEMEA SUI DI PI, Lausanne, Switzerland, 2Department of Radiology, CHUV, Lausanne, Switzerland, 3LTS5, EPFL, Lausanne, Switzerland, 4Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China, 5Research Center for Medical Image Computing, Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China, 6Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China, 7Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, 8MR Collaboration Northeast Asia, Siemens Healthcare, Beijing, China |
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We investigate the potential of a Chinese-specific brain atlas derived from a large MR database of healthy Chinese subjects to accurately support Alzheimer’s Disease diagnosis using automated brain volumetry in the Chinese population. Our experiments show that disease detection sensitivity is higher than when using either a Westerner-specific atlas and normative ranges or combining a Westerner atlas with Chinese-specific normative ranges. These findings suggest that population-specific models improve the reliability of medical decision support systems based on automated brain volumetry. |
| 2353 | Prediction of early stage of AD based on functional connectivity network characteristics: an fMRI-based study | |
1Bio-medical Engineering, Capital Medical University, Beijing, People's Republic of China, 2Clinical Science, Philips Healthcare, Beijing, People's Republic of China |
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MCI (Mild Cognitive Impairment) is a pre-stage of Alzheimer’s Disease (AD). And the early detection of MCI is important for early treatment of AD patients. In this work, prediction efficiency of early stage of AD based on the functional connectivity network characteristics was evaluated by using a couple of classifiers with AAL_90 and AAL_1024 templates. The results showed that brain functional characteristics were effective in the prediction of MCI with a SVM-based classifier. And a more fine template could improve prediction accuracy. |
| 2354 | Acupoint-Specific Effect of Acupuncture in Alzheimer’s Disease: A Functional MRI Study | |
1Xuanwu hospital, Capital Medical University, Beijing, People's Republic of China, 2University of Science and Technology of China, Hefei, China, 3Oriental Hospital，Beijing University of Chinese Medicine, Beijing, China |
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Acupuncture has been a major therapeutic method in Chinese medicine for treating Alzheimer’s disease (AD) with validation and safety. In this study, we use functional magnetic resonance imaging (fMRI) to investigate the acupoint-specific effect of acupuncture in treating for AD. We found acupuncture at real acupoints activated brain areas primarily in the left uvula, right superior temporal gyrus and right uncus, while acupuncture at sham acupoints only activated areas in the left insula. These results showed that acupoint-specific effect of acupuncture presented by fMRI may help to facilitate its clinical use in AD treatment. |
| 2355 | Disrupted brain connectivity networks in Alzheimer's Disease | |
1Center for Biomedical Imaging Research, Tsinghua University, Beijing, People's Republic of China, 2Institute of Affective and Social Neuroscience, Shenzhen University, Shenzhen, People's Republic of China, 3Neuroimaging Center, University Medical Center Groningen, University of Groningen, Groningen, Netherlands, 4Department of Radiology, University of Washington, Seattle, WA, United States |
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In this study, we used graph theory-based approaches to explore the topological organization of whole brain network in Alzheimer’s Disease. We performed resting state fMRI on 6 AD patients and 19 normal controls. Topological properties such as small-world, efficiency and nodal centrality were calculated and nonparametric permutation tests were further used for group comparisons. The results showed that high-level cognitive regions including parietal cortex, vmPFC, precuneus and emotional regions including caudate and thalamus were changed in the topological metrics, this may be a biomarker for AD classification. |
| 2356 | Evaluating glymphatic system by diffusion images: Alzheimer's disease cases analyzed by Diffusion Tensor Image analysis Along Perivascular Space (DTI-ALPS) | |
1Dept. of Radiology, Nagoya University, Nagoya, Japan, 2Dept. of Biomedical Information Sciences, Hiroshima City University, Hiroshima, Japan, 3Dept. of Psychiatry, Nara Medical University, Kashihara, Japan |
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We tried to evaluate the activity of human glymphatic system by diffusion images. Our subjects were Alzheimer's disease (AD), in which it is known that the activity of the glymphatic system is impaired in animal experiments. We evaluated the diffusivity along the perivascular spaces as well as projection fibers and association fibers, and correlated them with MMSE score. There were significant positive correlation between diffusivity along perivascular spaces and MMSE score, indicating impaired water diffusivity related to AD severity. Our result may indicate that activity of the glymphatic system can be evaluated by diffusion images. |
| 2357 | Can EPVS reflect Cerebral Blood Flow and Cognitive State in MCI and AD Patients? | |
1First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China |
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EPVS may reflect underlying cerebral small vessel disease. We assumed the presence of EPVS were associated with cerebral blood flow (CBF)reduction ,and can accurately reflect the cognitive state.The study verifies a good coherence between EPVS and CBF in BG and CS of AD patients , and furthermore reflects of EPVS as the biomarker of cognitive status to a certain extent. |
| 2358 | A Potential Biomarker of Alzheimer's Disease: T1sat of the Thalamus | |
1Department of Computer Science, State University of New York at Binghamton, Binghamton, NY, United States, 2Department of Radiation Oncology, Washington University, St Louis, MO, United States, 3Center of Neuroscience, University of Pittsburgh, PA, United States, 4Department of Psychology, University of Pittsburgh, PA, United States, 5Department of Psychiatry and Neurology, University of Pittsburgh, PA, United States |
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Biomarkers for Alzheimer’s disease (AD) are crucial for early diagnosis and treatment monitoring once therapies become available. In this study, the spin-lattice relaxation time in the rotating frame with (T1sat) and without (T1nosat) off-resonance saturation was measured at 1.5 T in the cardiovascular health study cognition study cohort. Cross-sectional and longitudinal studies of the normalized difference (ΔT1RF) between T1sat and T1nosat revealed regions of statistical significance in the brain that are associated with dementia pathogenesis. ΔT1RF changes in the thalamus were consistent for the cross-sectional and longitudinal studies, indicating that ΔT1RF could be a promising imaging biomarker for AD. |
| 2359 | Hippocampal atrophy is correlated to cerebrospinal fluid levels of ceruloplasmin, neuroinflammation and total tau in Alzheimer’s disease | |
1Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom |
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The aim of the study was to characterise the relationship between cerebrospinal fluid (CSF) iron regulatory proteins (ferritin, ceruloplasmin), neuroinflammation and MRI-derived hippocampal volume in healthy controls, mild cognitive impairment and Alzheimer’s disease subjects. Ceruloplasmin positively correlated with neuroinflammation and ferritin in MCI and AD while in the latter group, it was negatively correlated with hippocampal volume. Ferritin positively correlated with neuroinflammation in HC and AD but also with tau levels in MCI. Iron dyshomeostasis, neuroinflammation and tau metabolism may increase hippocampal atrophy and aggravate AD pathogenesis. |
| 2360 | Altered Hippocampal Functional Connectivity with PCC in SCI, MCI and AD | |
1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong, 2Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong, 3State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, 4MR Clinical Science, Philips Healthcare, Hong Kong, Hong Kong, 5State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, Hong Kong, 6Alzheimer's Disease Research Network, The University of Hong Kong, Hong Kong, Hong Kong |
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Brain imaging research has elucidated the structural and functional changes at the clinical stages of AD and MCI, however, the characteristics of resting-state functional connectivity of SCI are largely unstudied. Hippocampus is among the first regions targeted by AD pathology. In this study, we employed resting state fMRI to study the connectivity between hippocampus and posterior cingulate cortex in SCI, MCI and AD groups. In the preliminary results, the connectivity between hippocampus and PCC in SCI was found stronger than control and other two neurodegenerative groups which may suggest that compensatory mechanisms providing preserved hippocampal pathway in SCI. |
| 2361 | Brain iron load, as measured by Quantitative Susceptibility Mapping, promotes beta-Amyloid associated functional brain change in elderly subjects but not in Super-Agers | |
1Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland, 2F.M. Kirby center for Functional Brain Imaging, Kennedy Krieger Institute and Johns Hopkins School of Medicine, MD, United States, 3Department of Nuclear Medicine, University of Zurich, Switzerland |
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To investigate whether brain iron load has an impact on Aβ associated functional brain change, this study investigated a large sample of cognitively healthy adults including 44 Super-Agers (subjects over the age of 85 without cognitive impairments) using simultaneous assessment of Amyloid-PET for Aβ-plaque-density, QSM for estimation of iron load and resting-state-fMRI. Our findings indicate that the combination of Aβ-plaque-density with other neurodegenerative change (iron), has an impact on brain functionality, reflected by significant changes of resting state functional connectivity. Additionally, Aβ-plaque-density had no significant effect on functional connectivity in Super-Agers. |
| 2362 | Demonstration of Abnormal Cortical Layers In Alzheimer's Disease Using Subtracted Tissue Attenuated Inversion Recovery (STAIR) Pulse Sequences | |
1Radioliogy, Univ. of California, San Diego, San Diego, CA, United States |
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The use of subtracted STIR images designed to null white and gray matter respectively is illustrated in formalin fixed brain samples at 11.7T. The images show the normal layers of the cerebral cortex with high contrast. The layers were less well seen, or not seen at all in Alzheimer’s Disease samples. Use of MT pulses with the STIR sequences produces high positive and negative contrast on difference images. The STIR subtraction technique made have general application, and be used with different forms of data acquisition. It may also be useful in other clinical situations for demonstrating changes due to small differences in T1 in the presence of long T1 fluids. |
| 2363 | Motor cortex hypointensity on SWI is associated with APOE status in cognitive impaired patients | |
1Radiology, Konkuk University Medical Center, SEOUL, Korea, Republic of, 2Neurology, Konkuk University Medical Center, SEOUL, Korea, Republic of |
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We evaluated the prevalence and its associated risk factors of motor cortex hypointensity on SWI in cognitive impaired patients. This retrospective study included 116 cognitively impaired patients (28 Alzheimer disease patients and 88 mild cognitive impaired patients). Among them, 83 patients showed positive motor cortex hypointensity on SWI and it was associated with age. Furthermore, the group with positive motor cortex hypointensity on SWI had less APOE4 allele carriers than negative group and this shows (+) APOE4 allele may act as an accelerating factor of cognitive decline even before iron accumulation starts to show changes in the motor cortex. |
| 2364 | Racial differences in cerebral microcirculatory function and cognitive function | |
1Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States, 2Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States |
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We examined racial differences in cerebrovascular reactivity (CVR) to carbon dioxide and their associations with cognitive function among patients with mild cognitive impairment and hypertension. The results provide evidence for association between impaired CVR and executive dysfunction. Hypertensive African Americans have more compromised cerebral microcirculatory function compared to Caucasians. |
| 2365 | Synergistic Effect of β-Amyloid and Microvascular Abnormality on Longitudinal Cognitive Decline in Elderly Subjects at Risk for Alzheimer’s Disease (AD) | |
1Neurosection, Div. of MRI Research, Dept. of Radiology, 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, 3Institute for Biomedical Engineering, University of Zürich and ETH Zürich, Zürich, Switzerland, 4Division of Psychiatry Research and Psychogeriatric Medicine, University of Zürich, Zürich, Switzerland, 5Division of Nuclear Medicine, University of Zürich, Zürich, Switzerland, 6Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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Progressive impairment in multiple cognitive domains is a clinical hallmark of Alzheimer’s Disease (AD), which is the most frequent cause for dementia in the elderly and is neuropathologically characterized by both cerebral β-amyloid (Aβ) accumulation and microvascular abnormalities. Here, we report significant co-localization of regions with microvascular abnormalities measured by arteriolar-cerebral-blood-volume (CBVa) MRI and Aβ accumulation measured by PiB-PET in elderly subjects at-risk for AD. Multiple regression analysis suggested that CBVa and Aβ may have a synergistic effect on longitudinal cognitive decline in these subjects . Both variables may need to be considered for secondary prevention trials in such populations. |
| 2366 | The mediating effects of functional disconnection on the association between structural disconnection and cognitive impairment in symptomatic carotid artery disease | |
1Radiological Sciences, Division of Clinical Neurosciences, School of Medicine, University of Nottingham, Nottingham, United Kingdom, 2Sir Peter Mansfield Imaging Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom |
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This study investigated the association between functional disconnection of cognitive networks, structural disconnection indexed as microscopic damage of specific white matter tracts, and global cognitive impairment in symptomatic carotid artery disease. The findings regarding the mediating effects of functional disconnection on the association between structural disconnection and global cognitive impairment provided promising implications for future studies that develop therapies for patients with vascular cognitive disorder. |
| 2367 | The Correlation of Olfactory Dysfunctions and Hippocampal Atrophy in Patients with Cognitive Impairment: A Potential Clinical Marker for Alzheimer’s Disease | |
1Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China, NanJing, People's Republic of China, 2Department of Neurology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China, NanJing, People's Republic of China, 3Department of Radiology, Pennsylvania State College of Medicine, Hershey, PA, USA, Hershey, PA, United States |
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Olfactory deficits have been observed in subjects with Alzheimer’s disease (AD) and its potential as a biomarker has been demonstrated by several recent studies. However, its sensitivity and specificity in detecting early AD have not been validated in the Chinese population where aging population is growing rapidly. In this study, by using a 3.0 T MR scanner, we evaluate the presence of olfactory deficits and hippocampal volume loss measured by FreeSurfer (6.0) based on local population in China, to validate the use of olfactory test battery as a clinical AD marker. |
| 2368 | Subcortical Nuclei Iron Deposition of Alzheimer's Patients on MRI-QSM: Maybe a Diagnostic Indicator | |
1Department of Radiology, China-Japan Friendship Hospital, Beijing, People's Republic of China, 2Department of Nuclear Medicine, Xuanwu Hospital,Capital Medical University, Beijing, People's Republic of China, 3GE Healthcare, Beijing, People's Republic of China |
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Based on gradient echo (GRE) magnetic resonance phase data, quantitative susceptibility mapping (QSM) is a novel technique which allows the non-invasive assessment of magnetic tissue susceptibility distribution in mild alzheimer’s disease (AD). In this study ,we investigated the correlation between mini-mental state examination (MMSE) and bulk tissue magnetic susceptibility in subcortical nuclei of 14 mild AD subjects and 14 cognitively healthy controls scanned at 3T . A strong linear correlation between them was found in caudate nucleus and dentate nucleus. Hence, QSM can be used for early AD diagnosis and intervention. |
| 2369 | Hippocampal T1-weighted and FLAIR contrast is associated with CSF biomarkers in asymptomatic individuals with parental history of Alzheimer’s disease | |
1Cerebral Imaging Centre, Douglas Mental Health Institute, Montreal, QC, Canada, 2Douglas Mental Health Institute, Montreal, QC, Canada |
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Cerebrospinal fluid (CSF) β-amyloid and phosphorylated-tau are consistently used as biomarkers related to the pathophysiology and clinical severity of individuals in the earliest phases of Alzheimer’s disease (AD). This study shows that T1-weighted and FLAIR signal intensity in the hippocampal subfields, normalized using the fimbria, are associated with ApoE4 status and CSF biomarkers. The FLAIR results suggest that presence of inflammation in the subiculum of ApoE4 carriers and in the CA1 and molecular layers of the hippocampus in subjects with low CSF β-amyloid burden as tau pathology increases. |
| 2370 | Modulated the Physiological Response Delay to Prevent Overestimating the Disruption of Default Mode Network in Alzheimer’s Disease | |
1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, 2Department of Medical Imaging, Taipei Medical University-Shuang Ho Hospital, New Taipei City, Taiwan, 3Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, Taipei, Taiwan, 4Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland |
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This study quantified the impact of physiological noise correction in characterizing the resting-state fMRI in Alzheimer’s disease (AD) patients with age- and gender-matched 17 healthy subjects and 15 AD patients. Using a seed-based correlation method with seeds at posterior cingular cortex and medial prefrontal cortex, we found that the difference in the functional connectivity between AD patients and healthy controls was significantly reduced when physiological noise was suppressed. |
| 2371
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Association between whole brain functional connectivity and cortical thickness throughout healthy aging | |
1InBrain Lab, Department of Physics, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil |
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The aging process entails morphological and functional alterations in the human brain. Using magnetic resonance imaging data of 130 subjects aged between 18 and 81 years from a publicly available dataset we obtained whole brain cortical thickness estimates and resting state connectivity to study how healthy aging affects these. Additionally, we studied the relationship between cortical thickness and functional connectivity. A heterogeneous thinning profile was observed and also a dominance in increases in connectivity, with few decreases. Connectivity correlates with thickness with temporal and occipital seed ROIs. These results might help to understand how connectivity and thickness relate in neuropathologies. |
| 2372 | Exaggeration of Tau Pathology by Amyloid-β production in PS2APPxTauP301L Transgenic Mouse Model of Alzheimer’s Disease | |
1Biomedical Imaging, Genentech, South San Francisco, CA, United States, 2Neuroscience, Genentech, South San Francisco, CA, United States, 3Pathology, Genentech, South San Francisco, CA, United States |
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The PS2APP, PS2APPxTauP301LHet, TauP301LHomo, TauP301LHet transgenic mouse models of AD were characterized using MRI, and various regional brain atrophies were detected using a completely automated analysis by SPM-8. Furthermore, through MRI (both ROI and voxel based morphometry) and histology we showed that the presence of PS2APP mutation in PS2APPxTauP301LHet triple transgenic mouse model exaggerates the Tau pathology. The presented results will enable MRI as a great tool to non-invasively assess the disease progression over time in preclinical therapeutic studies targeting Aβ and Tau pathology. |
| 2373 | The relationship between brain white matter hyperintensities burden and age-related neuropathologies is location dependent | |
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, 3Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, United States, 4Department of Pathology, Rush University Medical Center, Chicago, IL, United States, 5Department of Diagnostic Radiology, Rush University Medical Center, Chicago, IL, United States |
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White matter hyperintensities (WMH) are white matter lesions appearing hyperintense in T2-weighted MRI. WMH are common in older adults and have been associated with increased risk of cognitive decline and dementia. Previous efforts have attempted to identify the neuropathologies associated with whole brain WMH burden. However, it is yet to be determined if the relationship between regional WMH burden and age-related neuropathologies is the same, or varies, in different parts of the brain. Therefore, the purpose of this research was to investigate the association between regional WMH burden and neuropathologies in a community cohort of older adults. |
| 2374 | MRI of longterm changes in vascularization and functional connectivity in a mouse model of vascular cognitive impairment | |
1Department of Experimental Neurology, Center for Stroke Research Berlin, and NeuroCure, Charité University Medicine Berlin, Berlin, Germany, 2Charité Core Facility 7T experimental MRIs, Charité University Medicine Berlin, Berlin, Germany, 3Department of Neurology, Berlin Center for Advanced Neuroimaging, NeuroCure Clinical Research Center Neuroimmunology, and Berlin School of Mind and Brain, Charité University Medicine Berlin and Humboldt University Berlin, Berlin, Germany, 4School of Life Sciences, University of Nottingham, Nottingham, United Kingdom |
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Chronic mouse brain hypoperfusion produces white matter damage; a feature of vascular cognitive impairment. Despite growing interest in this model, we have struggled to observe a strong phenotype. The present study aimed to improve the phenotype through extended hypoperfusion (6m). We examined the effect on various MR biomarkers including functional connectivity and vascular remodeling. We found massive structural changes including arterial neovessels, small subcortical strokes, and microbleeds. Animals showed behavioral deficits accompanied by changes in resting state MRI signals of the cingulate cortex, which is functionally connected to regions related to behavior (hippocampus) and emotion (amygdala). |
| 2375 | White matter hyperintensity burden assessed ante-mortem and post-mortem on the same older adults | |
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, 3Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, United States, 4Department of Pathology, Rush University Medical Center, Chicago, IL, United States, 5Department of Diagnostic Radiology, Rush University Medical Center, Chicago, IL, United States |
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White matter hyperintensities (WMH) are commonly observed in brain MR images of older adults. Recently, more and more research studies assess WMH burden using ex-vivo MRI, aiming at directly linking WMH to the underlying neuropathologies detected at autopsy. The purpose of this work was twofold: 1) to investigate the relationship between WMH burden assessed in-vivo and ex-vivo on the same older adults, and 2) to test the hypothesis that WMH burden assessed ex-vivo is higher than that assessed in-vivo for longer ante-mortem intervals (AMI) (i.e. from in-vivo MRI to death). |
| 2376 | Fast multivariate relaxometry can differentiate neurodegenerative disease processes and phenotypes | |
1NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montréal, Montreal, QC, Canada, 2Athinoula A. Martinos Center for Biomedical Imaging, MGH, Charlestown, MA, United States, 3Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden, 4Department of Neurology, Karolinska University Hospital, Stockholm, Sweden, 5Center for Medical Imaging Science and Visualization, CMIV, Linköping, Sweden, 6SyntheticMR, Linköping, Sweden, 7Montreal Health Institute, Montreal, QC, Canada, 8Harvard Medical School, Boston, MA, United States, 9Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montréal, QC, Canada, 10Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden, 11Department of Radiology, Karolinska University Hospital, Stockholm, Sweden |
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Hereditary diffuse leukoencephalopathy with spheroids (HDLS) and multiple sclerosis (MS) are demyelinating and neurodegenerative disorders that can be hard to distinguish clinically and radiologically. Here, we present a framework to extract independent physiological sources of signal from time-efficient multiple quantitative relaxometry (T1, T2 and PD maps) to characterize varying degrees and mechanisms of tissue disruption. The method can aid in the differentiation of HDLS and MS (p=0.007), as well as identify MS subtypes (p=0.0007), which would be helpful in ensuring a correct diagnosis and treatment of these disorders. |
| 2377 | What Happens to the Hippocampus 12-months After Training? A Longitudinal Linear Mixed Effects Model Analysis of Mild Cognitive Impairment in the SMART Trial | |
1Regenerative Neuroscience Group, Brain and Mind Centre, Sydney, Australia, 2Brain and Mental Health Laboratory, Monash Institute of Cognitive and Clinical Neuroscience, Monash University, Sydney, Australia, 3School of Psychiatry, University of New South Wales, Sydney, 4Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Sydney, 5Exercise Health and Performance Faculty Research Group, Faculty of Health Sciences and Sydney Medical School, The University of Sydney, 6Hebrew SeniorLife and Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, 7Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW, Australia, 8Dementia Collaborative Research Centre, University of New South Wales, Sydney, NSW, Australia, 9Exercise Health and Performance Faculty Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW, Australia., 10Department of Psychiatry, School of Medicine, University of Adelaide, Adelaide, SA, Australia, 11School of Exercise Science, Australian Catholic University, Strathfield, NSW, Australia., 12Clinical and Rehabilitation Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW, Australia., 13Department of Medicine and the Diabetes Center, University of California, San Francisco, San Francisco, CA, USA, 14School of Medical Sciences, Sydney Medical School, University of Sydney, Sydney, NSW, Australia. |
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Mild cognitive impairment (MCI) increases future risk of dementia, however, several studies have shown that mental and physical exercise reduce this risk. From the Study of Mental Activity and Resistance Training (SMART) we have previously shown significantly improved global cognitive function immediately after 6 months of progressive resistance training in MCI. In this analysis, we compare longitudinal hippocampal volume change in MCI using linear mixed effects models over an 18-month period comprised of a 6-month training phase and a 12-month post training follow-up. Our results show both isolated cognitive and progressive resistance training significantly diminished the rate of left hippocampal atrophy compared to a double sham intervention across training and an extended follow-up period. |
| 2378 | Extraction of Both Dynamic Functional and Structural Connectivity from Resting-state fMRI for MCI Classification | |
1Department of Radiology and BRIC, University of North Carolina at Chapel Hill, CHAPEL HILL, NC, United States |
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In this abstract, we show that the diagnosis accuracy of mild cognitive impairment (MCI) can be significantly improved by integrating dynamic information contained in the traditional functional connectivity (FC) from grey matter (GM) regions and the functional correlation tensors (FCT) from white matter (WM) regions, both computed from resting-state fMRI (RS-fMRI). The advantages of our method include: 1) dynamic FC is exploited to reveal rich time-varying information in FC, and 2) the anatomical structure information within WM can be well incorporated in RS-fMRI. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2379 | Magnetic resonance spectroscopy demonstrates decreased glutamate in the anterior cingulate cortex in individuals with spinal cord injury | |
1Department of Radiology, University of British Columbia, Vancouver, BC, Canada, 2International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada, 3Faculty of Medicine (Division of Neurology), University of British Columbia, Vancouver, BC, Canada, 4Faculty of Education (School of Kinesiology), University of British Columbia, Vancouver, BC, Canada, 5Department of Pathology & Laboratory Medicine, University of British Columbia |
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We investigated metabolites in the anterior cingulate cortex using magnetic resonance spectroscopy in individuals with spinal cord injury (SCI). Short-TE PRESS at 3T provided reliable fits for glutamate (Glu), N-Acetyl-aspartate (NAA), total creatine (tCr), myo-Inositol and total choline. SCI patients had 11.3 % less Glu. Given the role of Glu in synaptic transmission between neurons and also between neurons and oligodendrocytes, reduced Glu in SCI may reflect decreased synaptic density and activity due to a loss of sensory input in the anterior cingulate cortex. Further research investigating the effect of sensory input loss on metabolite concentrations in SCI is warranted. |
| 2380 | Neurodegeneration and its interaction with motor impairment in sub-acute SCI revealed by quantitative MRI | |
1Spinal Cord Injury Center Balgrist, University of Zurich, Zurich, Switzerland, 2Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom, 3Wellcome Trust Centre for Neuroimaging, 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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Spinal cord injury (SCI) leads to immediate sensorimotor and autonomic dysfunction and SCI patients generally show little clinical recovery within the first year after injury. Early structural changes at the spinal and brain level and their interactions with recovery rate are not well understood. The aim of our study was to reveal trauma-induced neurodegeneration and its interaction to impairment within early stage after injury employing quantitative neuroimaging technique. Our finding showed that significant atrophy and microstructural changes initiated in neural sensorimotor system within already early stage after SCI and quantitative neuroimaging methods hold potential to disclosing these neurodegeneration mechanisms. |
| 2381 | Progressive ventricles enlargement and CSF volume increases as a marker of neurodegeneration in SCI patients: A longitudinal MRI study | |
1Spinal Cord Injury Center Balgrist, University of Zurich, Zurich, Switzerland, 2Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany, 3German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany, 4Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom, 5Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom, 6Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany |
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Following Spinal Cord Injury the sensorimotor and limbic system immediately undergo progressive neurodegeneration (atrophy). Next to the focal grey and white matter atrophy, localized CSF and ventricular volume changes may provide additional biomarkers for brain atrophy. We therefore aimed to track brain atrophy by means of CSF volume changes and ventricular enlargements over two years following SCI. Our finding showed an increase of local CSF volume as well as ventricles enlargement in patients over time. The CSF volume which is normally used as a biomarker of general atrophy, showed also sensitivity to local degenerative changes in SCI. |
| 2382 | Brain metabolism and temperature assessment in traumatic brain injury subjects using 3D Echo-planar Spectroscopic Imaging | |
1Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore, 2Miller School of Medicine, University of Miami, Miami, FL, United States |
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Traumatic brain injury (TBI) results in a broad spectrum of symptoms and disabilities and has a high rate of mortality and morbidity. TBI is associated with elevated brain temperature due to inflammation. TBI has heterogeneous consequences of pathophysiology, changed intracranial dynamics and cerebral metabolism. In some cases there is an increase in ICP and cerebral perfusion which makes the management of the injury difficult . Therapeutic hypothermia is recommended as one of the acute management techniques as it increases neuroprotection, decreases cerebral metabolism and ICP. To induce hypothermia and monitor the brain temperature a noninvasive and accurate assessment of cerebral temperature is essential. MR based temperature measurement based on the water resonance frequency, relaxation times (T1, T2), spectroscopy, proton density, diffusion etc. have been widely used. Echo-planar spectroscopic imaging (EPSI) method has the advantage of simultaneous acquisition of water and spectrum in a single TR, by which we can acquire the whole brain spectrum in a short time . In this study we have explored changes in brain temperature due to cerebral metabolic changes in control, mild and moderate TBI subjects. |
| 2383 | Thalamic Atrophy following mTBI is Associated with Persistent Post-Concussive Symptoms and Cognitive Fatigue | |
1Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States, 2Electrical and Computer Engineering, Johns Hopkins University |
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Even mild TBI patients with negative CT and MRI may experience persistent post-concussive symptoms (PCS) and declined cognition more than 3 months post injury. In this prospective study of regional brain volume changes in mTBI patients, we found progressive thalamic atrophy from acute to chronic stages post injury, especially within the patient group that showed persistent PCS at 6 months. Thalamic volume atrophy also correlated with cognitive fatigue and processing speed within the same symptomatic mTBI group. Further studies on vulnerability of the thalamus may provide more insights into TBI recovery and lead to potential Therapies. |
| 2384 | Effects of cumulative non-concussive head impact exposure associated with youth football on MRI measures of gray matter structure | |
1Radiology, Wake Forest School of Medicine, Winston Salem, NC, United States, 2Biomedical Engineering, Wake Forest School of Medicine, 3Radiology, University of Texas Southwestern Medical Center, 4Biostatistical Sciences, Wake Forest School of Medicine, 5Radiology & Biomedical Engineering, Wake Forest School of Medicine, 6Family and Community Medicine, Wake Forest School of Medicine, 7Neurosurgery, Wake Forest School of Medicine, 8Radiology, Biomedical Engineering, and Clinical and Translational Sciences Institute, Wake Forest School of Medicine |
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Millions of children play American football, however, youth players are largely absent from studies addressing the public health questions about safety and concussion. Furthermore, many studies investigating effects of sports-related head impact exposure on brain structure have focused on white matter, with few evaluating the effects on gray matter (GM) structure. In this study, we combined measures of head impact biomechanics and brain MRI to investigate the effects of repetitive non-concussive exposure on gray matter volume and microstructural integrity. We demonstrate statistically significant relationships between exposure metrics and MRI measures of GM diffusion characteristics after one season of youth football. |
| 2385 | Repetitive Head Impact Exposure and Later-Life Neurochemistry: A Magnetic Resonance Spectroscopy Investigation in Symptomatic Former NFL Players | |
1Neurology, Boston University School of Medicine, Boston, MA, United States, 2Radiology, Center for Clinical Spectroscopy, Brigham and Women's Hospital, Harvard Medical School, MA, 3Biostatistics, Boston University School of Public Health, 4Data Coordinating Center, Boston University School of Public Health, MA, 5Psychiatry, Psychiatry Neuroimaging Laboratory, Radiology, Brigham and Women's Hospital, Harvard Medical School, MA, 6Neurology, Boston University School of Medicine, MA, 7Neurology, Neurosurgery, Boston University School of Medicine, MA, 8Concussion Legacy Foundation, 9Simbex, 10Thayer School of Engineering, Dartmouth College, 11Environmental Health, Boston University School of Public Health, MA, 12Neurology, Pathology and Laboratory Medicine, Boston University School of Medicine, 13Neurology Service, VA Boston Healthcare System, 14VA Boston Healthcare System, 15Department of Veterans Affairs Medical Center, Bedford, 16Neurology, Neurosurgery, Anatomy & Neurobiology, Boston University Alzheimer's Disease and CTE Center, Boston University School of Medicine, MA |
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This study examined magnetic resonance spectroscopy (MRS) as a potential biomarker for chronic traumatic encephalopathy (CTE). 79 former National Football League players and 23 same-age controls completed MRS. Cumulative head impact index (CHII) estimated repetitive head impact (RHI) exposure. Principal component analysis derived clinical composites. Former NFL players had lower parietal white matter (PWM) NAA (p=0.048). Higher CHII predicted lower PWM creatine (p=0.028). Anterior cingulate gyrus (ACG) metabolites correlated with visual memory (p=0.008-0.044). ACG glutamate (p=0.032) and glutamate/glutamine (p=0.012) predicted psychomotor/executive function. Posterior cingulate gyrus myo-inositol predicted verbal memory (p=0.048). MRS may facilitate detection of RHI-related neurological conditions, including CTE. |
| 2386 | White matter microstructure in adolescent female soccer athletes: diffusion MRI relations with years of high-school experience, concussion history, and cognitive measurements. | |
1Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 2College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States, 3School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, United States, 4Department of Psychological Sciences, Purdue University, West Lafayette, IN, United States |
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Understanding how contact sports activities potentially affect the brains and cognitive abilities of adolescent athletes in both short and long-term scales is critical. Using 3 Tesla diffusion-weighted imaging (DWI) and tract-based spatial statistics, this study investigated the white matter microstructure of 13 high-school female soccer athletes over one competition season. No significant difference of DWI metrics across the season was observed. However, regression analyses showed significant effects of years of high-school experience and concussion history on the DWI metrics within corticothalamic and limbic pathways, and the abnormal changes of DWI metrics may relate to cognitive impairments. |
| 2387 | Quality control for human brain advanced diffusion imaging for assessment of concussion | |
1Neurology, Washington University School of Medicine in St. Louis, St. Louis, MO, United States |
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Most concussive brain injury is not readily detected in conventional MRI or standard DTI, requiring advanced imaging methodology. However, reliability of any newly developed imaging technology should be tested prior to starting full scale studies. Here we present a protocol which will enable inter-lab comparison of any advanced diffusion imaging technology with objective quantitative analysis. High spatial resolution diffusion imaging with optimized multiband pulse sequence performed on subjects twice at 1.25 mm isotropic voxel size. Post image processing including outlier exclusion and distortion correction was optimized. Brain parcellation based quantitative analyses was used to provide objective measures of reproducibility. |
| 2388 | MRI based early monitoring and quantitative assessment of macrophages infiltration after experimental traumatic brain injury in mice | |
1NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India, Delhi, India, 2Division of Stem Cell and Gene Therapy Research, Institute of Nuclear Medicine and Allied Sciences, Delhi, India, Delhi, India |
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The inflammatory response following traumatic brain injury (TBI) is regulated by phagocytic cells, comprising resident microglia and infiltrating macrophages. The present study was to monitor the early effect of monocytes/phagocytic accumulation and further to explore its kinetics in TBI mice. Localized macrophage population was monitored using USPIO nanoparticles enhanced in vivo serial magnetic resonance imaging (MRI). Flow cytometry based gating study was performed to discriminate between resident microglia (Ly6GˉˉCD11b+CD45low) and infiltrating macrophages (Ly6GˉCD11b+CD45high). Imaging and flow cytometric analysis revealed that maximum macrophage infiltration occurs between 66-72 h post injury (42-48 h post administration of USPIO) at the site of inflammation. |
| 2389 | Proton Magnetic Resonance Spectroscopy of Mild Traumatic Brain Injury in the Military | |
1Center for Clinical Spectroscopy, Brigham and Women's Hospital & Harvard Medical School, Boston, MA, United States, 2U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States |
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The objective of this ¹H MRS study was to determine the neurochemical profiles of military members with mild Traumatic Brain Injury (mTBI) and compare with age-matched, healthy military controls. Analysis of metabolite concentrations in three brain regions revealed a significant global decrease in total creatine (tCr) in mTBI subjects, as well as elevated GSH in the posterior cingulate and increased Glx in both posterior white matter and anterior cingulate regions, when compared to controls. These results could identify key biomarkers of mTBI and indicate neuroinflammatory changes and impaired brain function or integrity in mTBI. |
| 2390 | Simultaneous detection of glucose and glutamate by CEST MRI: a preliminary study for experimental brain injury | |
1Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD, United States, 2Radiology and Imaging Sciences, National Institutes of Health |
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The current study investigated the CEST sensitivity and specificity for simultaneous glucose (glucoCEST) and glutamate (gluCEST) detection on a phantom and a rodent brain injury. Using a median saturation power (2μT) and short saturation duration (2s), the MTRasym at 1.2, 2.1 and 2.9ppm could detect the glucose content, while the MTRasym at 3ppm could measure the glutamate in vivo. The glucoCEST results were compared in parallel to the 18F-FDG PET detecting the tissue uptake of glucose, while the gluCEST data were shown comparable to 18F-DPA PET radio-ligands binding to translocator protein (TSPO) for imaging microglial activation in the injured brain. |
| 2391 | Longitudinal changes of cerebral perfusion in patients with moderate traumatic brain injury | |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 2Department of Dermatology, Massachusetts General Hospital, Boston, MA, United States, 3Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, 4Department of Emergency Medicine, Massachusetts General Hospital, Boston, MA, United States, 5Department of Cognitive, Linguistic and Psychological Sciences, Brown University, Providence, RI, United States |
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There is increasing evidence that neurovascular dysregulation contributes to the persistent symptoms in patients with traumatic brain injury (TBI). Damaged microvasculature may disrupt the neurovascular coupling, where the local cerebral blood flow (CBF) no longer matches the metabolic requirements of the tissue. In the present study, we found that there was a diffuse hypoperfusion at thalamus, posterior cingulate gyrus, precuneus and white matter in 2-week follow-up scan relative to the 48-hour initial and 3-month follow-up scans. Low perfusion was sustained in both frontal and parietal cortices in 3-month follow-up scan. Our perfusion findings in these brain regions suggest that hypoperfusion may play a role in the post-traumatic symptoms of moderate TBI. |
| 2392 | Longitudinal changes of neurovascular responses to breathhold challenge in patients with moderate traumatic brain injury | |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 2Department of Dermatology, Massachusetts General Hospital, Boston, MA, United States, 3Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, 4Department of Emergency Medicine, Massachusetts General Hospital, Boston, MA, United States, 5Department of Cognitive, Linguistic and Psychological Sciences, Brown University, Providence, RI, United States |
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There is an increasing evidence that neurovascular dysregulation contributes to the persistent symptoms in patients with traumatic brain injury (TBI). Damaged microvasculature may disrupt the neurovascular coupling, especially under physiological stress, where the local cerebral blood flow (CBF) no longer matches the metabolic requirements of the tissue. Our findings of negative or abnormally delayed blood oxygenation level dependent (BOLD) signal changes in response to breathhold challenge can potentially be used as an imaging marker to localize subtle abnormal vascular function in individual patients with moderate TBI. The restoration of abnormally delayed BOLD responses at chronic stage suggest that such an imaging marker may be used to follow up the patients. |
| 2393 | A Repetitive Traumatic Brain Injury Model Characterized with Diffusion Tensor and Diffusion Kurtosis Imaging with Neuropathological Correlation | |
1Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 2Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States, 3Department of Psychiatry, University of Maryland School of Medicine at Baltimore, Baltimore, MD, 4Radiology, University of New Mexico, Albuquerque, NM, United States, 5Radiology and Radiological Sciences, Uniformed Services University of the Health Sciences, Bethesda, MD |
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Mild traumatic brain injury (mTBI) often involves single (s-mTBI) or repetitive (r-mTBI) head injury, which may differ in the potential for long term symptoms and chronic neurodegeneration. Non-invasive approaches that can detect damage and predict outcome are a high priority for clinical care of mTBI patients. Magnetic resonance (MR) diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) techniques can identify microstructural changes associated with Gaussian (DTI) and non-Gaussian (DKI) water diffusion properties. Mouse models of s-mTBI and r-mTBI targeting anterior brain regions (impact site at bregma) were developed for longitudinal MRI studies with corresponding neuropathology. |
| 2394 | Neuroimaging in Concussion: A Magnetic Resonance Elastography Pilot Study | |
1Radiology, Mayo Clinic Arizona, Phoenix, AZ, United States, 2Neurology, Mayo Clinic Arizona, Phoenix, AZ, United States, 3Mayo Clinic Rochester, Rochester, MN, United States, 4Research, Mayo Clinic Arizona, Phoenix, AZ, United States |
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As concussion, even when symptomatic, can be occult on routine imaging, there is clinical need for a more accurate diagnostic assessment. The objective of this study was to assess the utility of brain magnetic resonance elastography (MRE), a non-invasive neuroimaging technique, to detect changes in brain stiffness in concussed patients relative to healthy controls. |
| 2395 | Quantitative Susceptibility Mapping in Mild Traumatic Brain Injury | |
1Department of Medical Imaging, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan, 2Translational Imaging Research Center, College of Medicine, Taipei Medical University, Taipei, Taiwan, 3School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, Taiwan, 4Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, 5Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan, 6Department of Medical Research, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan |
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The present study investigated whether quantitative susceptibility mapping is able to identify particular characteristics of alterations in white matter and other brain regions in patients with mild traumatic brain injury (mTBI). Our study suggests that quantitative susceptibility mapping is capable of indicating iron and myelin disturbances in white matter and thalamus for patients with mTBI. |
| 2396 | Imaging of thalamic calcium deposits due to sports-related concussion using Quantitative Susceptibility Mapping (QSM) | |
1Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 2MRI Clinical and Translational Research Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 3Department of Psychiatry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 4Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 5Department of Orthopaedics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States |
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This work explored the hypothesis that the activation of N-methyl-D-aspartate (NMDA)-receptors in the thalamus results in persistent calcium deposits after a sports-related concussion that can be visualized clinically with Quantitative Susceptibility Mapping at 3 Tesla. The study involved 22 retired professional contact-sports athletes and 45 controls. We found a significantly higher incidence of thalamic micro-calcifications in contact-sports athletes compared to controls, in particular in ice hockey players. |
| 2397 | Diffusion Tensor imaging assessment for the spinal cord injury using 9.4 Tesla | |
1Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia, 2Radiology department, College of applied medical sciences, Najran University, Najran, Saudi Arabia, 3Radiology Department, King Fahad Medical City, Ministry of health, Riyadh, Saudi Arabia, 4Radiology Department, King Saud for Chest and Respiratory diseases, Ministry of health, Riyadh, Saudi Arabia, 5Laboratory for Neural Injury and Repair, School of Biomedical Science, University of QLD, Brisbane, Australia |
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Spinal cord injury (SCI) is a devastating damage that can result in permanent disabilities. MRI provides precise details of spinal cord post traumatic compression, which are useful for the diagnosis of the injury, surgical planning, post-surgical measurements and estimation long-term outcomes (Kramer, Freund, & Curt, 2014). In this study, 4 SCI mice were scanned at the 9.4T to acquire high-resolution images and diffusion tensor imaging at two b-values. The area of both white and gray matter were measured in several slices and compared to the pre-injury imaging. Spinal cord white and gray matters were also examined using DTI. |
| 2398 | Traumatic Spinal Cord Injury Induces Cortical Diffusion MRI Changes | |
1Radiology, Washington University in Saint Louis, Saint Louis, MO, United States, 2Neurological Surgery, Washington University in Saint Louis, Saint Louis, MO, United States, 3Washington University in Saint Louis, Saint Louis, MO, United States |
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Spinal cord injury (SCI) is a significant public health problem. A major shortcoming limiting efforts to improve the treatment of SCI is the lack of quantifiable metrics on which to base clinical decisions. In current study, we have utilized diffusion basis spectrum imaging (DBSI) to more accurately differentiate and quantify axonal injury, demyelination, inflammation and edema/tissue loss. DBSI results suggest chronic SCI does result in axonal injury and edema/tissue loss at the level of the cerebral peduncle. These results demonstrated axons may be preserved rostral to the site of injury, and may provide some insight as to why some patients respond to more recent epidural stimulation even years out from injury. |
| 2399 | Assessing Functional and Structural Connectivity in ex-Professional Athletes | |
1School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada, 2Department of Electrical and Computer Engineering, McMaster University, 3Department of Linguistics and Languages, McMaster University |
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Recently there has been considerable attention directed towards the increased risk for head injuries that athletes face while participating in high impact sports. Furthermore, there is also heightened interest in asymptomatic sub-concussive blows that possibly lead to long term neurological deficits. The goal of this study was to investigate retired professional athletes, who played at least 4 seasons of Canadian football, using functional connectivity mapping and DTI techniques. When compared to an age matched control population, differences were observed both in functional and structural connectivity, suggesting that even years after retiring the brain still exhibits signs of damage. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2400 | Neonatal MRI rotational motion correction using a wireless accelerometer (WiMoCo) | |
1Academic Radiology, University of Sheffield, Sheffield, United Kingdom |
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A wireless accelerometer has been used to measure rotation angles on a dedicated neonatal MRI system. The measured angles have been used to help correct the k-space data to reduce ghosting artifacts. No interference between the accelerometer and the MR system was observed. Some limited improvement in ghosting was found but further work is required on the reconstruction algorithm. The device offers fast temporal resolution (10ms) and no sequence acquisition time overhead as it is a totally independent measurement system. |
| 2401 | Comparison of inhomogeneous magnetization transfer imaging with myelin water imaging (MWI) and diffusion tensor imaging (DTI) | |
1Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States, 2Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, 3Philips Healthcare, Germany, 4Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States, 5Philips Healthcare, Gainesville, FL, United States |
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Inhomogeneous magnetization transfer (ihMT) imaging is an enhanced magnetization transfer technique, which has been shown to produce a higher white/gray matter contrast compared to conventional MT methods. This contrast is thought to be originating from dipolar order effects in myelinated tissues. In this study we compare ihMT with myelin water imaging and diffusion tensor imaging. |
| 2402 | In-vivo 3D T1rho mapping of the whole Brain: Multi-component Analysis | |
1Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, United States |
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In this study, we demonstrate the in vivo feasibility of multicomponent 3D-T1rho relaxation mapping of whole brain using 3T MRI in five healthy subjects. Our preliminary results suggest that the bi-exponential model better represents the relaxation behavior in white matter and has potential to differentiate between different water compartments associated with myelin bound water (short component) and intra-extracellular water (long component). |
| 2403 | BrainVis: A cloud-connected 3D exploration and visualization tool for multi-modal neuroimaging data | |
1Mint Labs, Barcelona, Spain |
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Diffusion MRI tractography is central to the study of complex brain circuitry since it is the only non-invasive technique capable of measuring the brain’s wiring. Data visualization gets increasingly complex as tractography is combined with morphometric results in structural connectomes, and even more so when coupled with functional information from fMRI techniques. Such complex imagery, aggregating multi-modal information, 3D meshes, and statistical maps is often visualized using research tools with complicated user interfaces (UIs) and cluttered visualizations. BrainVis is a sophisticated, free 3D neuroimaging visualization tool with a simple UI aimed for effective exploration of neuroimaging data towards demonstrating neurobiological findings. |
| 2404 | Distributed rCBF changes caused by high frequency rTMS on lateral prefrontal cortex | |
1Hangzhou Normal University, Hangzhou, People's Republic of China |
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The repetitive application of transcranial magnetic stimulation (rTMS) on left dorsolateral prefrontal cortex (DLPFC) have been consistently shown to be beneficial for treating various neuropsychiatrical or neuropsychological disorders, however its neural mechanisms still remain unclear. In this study, we measured the effects of high-frequency left DLPFC rTMS using cerebral blood flow (CBF). The results showed the rTMS induced CBF redistribution in the default mode network, including increased rCBF in temporal cortex which was correlated with increased behavior performance, but reduced rCBF in precuneus and cerebellum. |
| 2405 | Exploring complementarity in multi-modal imaging of cortex microstructure: a diffusion and relaxometry study | |
1CRCHUM, Université de Montréal, Montreal, QC, Canada, 2MR Clinical Science, Philips Healthcare Canada, Markham, ON, Canada, 3NeuroPoly Lab, Ecole Polytechnique, Montreal, QC, Canada, 4Montreal Heart Institute, University of Montreal, Montreal, QC, Canada, 5CHUM Notre-Dame, Montreal, QC, Canada, 6CRCHUM, Montreal, QC, Canada, 7Université de Montréal, Montreal, QC, Canada, 8Division of Neurology, CHUM Notre-Dame, Montreal, QC, Canada, 9Department of Neuroscience, Université de Montréal, Montreal, QC, Canada |
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We explored the utility and complementarity of different diffusion and relaxometry metrics for cortical imaging. The following metrics were assessed for correlation: mean kurtosis (MK) from diffusion kurtosis imaging, intra-cellular volume fraction (ICVF), from the NODDI model, intra-neurite volume fraction (VINT), from the multi-compartment microscopic diffusion imaging (MCMICRO) model, R1 (=1/T1), R2* (=1/T2*) and the ratio of T1w/T2w images. Some global similarities can be seen between most cortical maps, while some features that suggest complementarity between diffusion and relaxometry maps were also observed. This study emphasizes the importance of better understanding and characterising the relationship between different MRI-derived metrics. |
| 2406 | Inductively coupled coils enable dental MRI with 350 um isotropic resolution in 2 min | |
1Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Freiburg, Germany, 2Faculty of Medicine, University of Freiburg, Freiburg, Germany, 3Division of Oral and Maxillofacial Surgery, Medical Center - University of Freiburg, Freiburg, Germany, 4Partner Site Freiburg, German Consortium for Cancer Research (DKTK), Heidelberg, Germany |
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High-resolution MRI of the lower jaw with an isotropic voxel size of 350 μm was performed at 3T using a 4-cm loop coil (LC) with and without an inductively coupled volume coil (ICC) enclosing the target region. Within this region, a much higher SNR was obtained and the resolution of anatomical details was strongly enhanced with the ICC. A new, custom-made holder for the LC improved the overall handling. Compared to earlier results, the scan time was reduced by 50%, now 2 minutes, to provide very high resolution MRI of 2-3 teeth. |
| 2407 | Quantitative Measurement of Cerebral Blood Volume Across 173 Brain Regions In Anethesia and Response to CO2 | |
1Physics, Northeastern University, Boston, MA, United States, 2Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 3Bioengineering, Northeastern University, Boston, MA, United States, 4Psychology, Northeastern University, Boston, MA, United States, 5Physics, Bioengineering, Northeastern University, Boston, MA, United States |
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We use a technique based on positive contrast quantitative imaging of super paramagnetic iron oxide nanoparticles with optimized parameters which we have previously introduced called QUTE-CE to measure CBV across a detailed rat brain atlas. This is done for an anesthetized state and then changes in an awake hypercapnic state are additionally quantified. The former provides a baseline for future work and reflects evolutionary and developmental forces. The latter demonstrates the potential of the technique for measuring changes in CBV and provides a measure of perfusion reserve. |
| 2408 | Carbon fiber electrodes for single-unit recording combined with artifact-free MRI | |
1Department of Chemical Engineering, Stanford University, Stanford, CA, United States, 2Department of Neurology and Neurological Sciences, Stanford University, 3Departments of Bioengineering, Neurosurgery, Electrical Engineering, Stanford University, Stanford University |
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Combining unit recording and fMRI is a powerful method that allows for interrogation of the brain at the cellular and network level. However, implanted metal recording electrodes produce susceptibility artifacts that distort MR images. Here, we fabricate single carbon-fiber electrodes and implant them into rat hippocampus and use an agarose phantom to quantify its MR distortion. These carbon-fiber electrodes record from a single unit in CA1 and distort a significantly lower volume of voxels compared to metal electrodes. These results lay the groundwork for an electrode design that can be used for single-unit recording and fMRI in same subjects. |
| 2409 | AUTOMATED DETECTION OF WHITE-MATTER AND CORTICAL LESIONS IN MP2RAGE AT ULTRA-HIGH FIELD USING A SINGLE SCAN | |
1Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 2Department of Radiology, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 3Signal Processing Laboratory (LTS 5), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 4Department of Radiology, Valais Hospital, Sion, Switzerland, 5Centre for Advanced Imaging, University of Queensland, Brisbane, Queensland, QC, Australia, 66. Siemens Healthcare Pty Ltd., Brisbane, Queensland, Australia, 7Siemens Medical Solutions USA, Boston, MA, United States, 8Translational Neuroradiology Section, Institute of Neurological Disorders and Stroke, National Institutes of Health (NIH), Bethesda, MD, United States, 9Medical Image Analysis Laboratory (MIAL), Centre d'Imagerie BioMédicale (CIBM), Lausanne, Switzerland, 10Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States, 11Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland |
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Ultra-high-field Magnetic Resonance Imaging (7T MRI) has been shown to be a valuable tool to assess focal and diffuse pathology in multiple sclerosis (MS) patients, both in grey- and in white-matter. In this work, we developed and evaluated a method to automatically assess MS lesion load using magnetization-prepared two inversion-contrast rapid gradient-echo (MP2RAGE) MRI at 7T. The validation was conducted in a cohort of twenty MS patients from two research centers through a ground truth based on manual segmentations performed by a radiologist. Our single-sequence segmentation accurately detects visible white-matter and cortical lesions. |
| 2410 | Harmonization for fractional anisotropy measurement at 3T in healthy subjects | |
1Department of Diagnostic Radiology, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, People's Republic of China, 2Department of Biomedical Engineering, School of Life Science and Technology, Xi’an Jiaotong University |
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In current clinical practice, the absence of standard protocol of diffusion tensor imaging (DTI) challenges the consistency of DTI data, and thus affects the accuracy of data group analysis. This study aims to assess the inconsistency of DTI-derived fractional anisotropy (FA) based on the different clinical protocols and further make them into harmonization. Results suggest the effects of slice thickness and b-value of FA are anatomy dependent, which is more stable in white matter with packed and orientation consistent fibers. Besides, a developed polynomial fitting model was used to make FA harmonization among different DTI protocols. |
| 2411 | Automatic registration of MRI and transcranial ultrasound for the analysis of neurological disorders | |
1PERFORM Centre, Concordia University, Montreal, QC, Canada, 2Department of Electrical and Computer Engineering, Concordia University, Montreal, QC, Canada, 3NeuroRx Research, Montreal, QC, Canada, 4Montreal Neurological Institute, McGill University, Montreal, QC, Canada, 5Department of Diagnostic and Interventional Neuroradiology, Montreal Neurological Hospital, Montreal, QC, Canada |
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Transcranial ultrasound (TCUS) can be used to diagnose and monitor a range of neurological conditions, such as Parkinson’s disease. However, reliable quantitative examination and multi-modal image analysis that involves TCUS require TCUS-MRI registration to guide the interpretation and measurement of the TCUS. We demonstrate that accurate rigid registration can be achieved through aligning gradient orientations of the 3D TCUS and an associated pseudo-TCUS constructed from the T1w MRI. |
| 2412 | Evaluation of multispectral segmentation of gray matter based on 3D T1-, T2 and T2-weighted FLAIR images for gray matter segmentation | |
1Diagnostic and Interventional Neuroradiology, University Hospital Tübingen, Tübingen, Germany, 2Neurology and Epileptology, University Hospital Tübingen, Tübingen, Germany |
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An ideal classification of brain tissue structures as segmented gray matter (GM) has been a challenge while using standard T1-weighted image. One of the important ways of addressing this issue would be to use additional information from multispectral imaging such as T2- and T2-weighted FLAIR images. We evaluated the effect of multispectral segmentation on GM segmentation using SPM12 VBM and compared it with T1-only segmentation. We found that T1-segmentation overestimates dura, meninges and vessels as GM. This problem was successfully addressed by multispectral segmentation, which should be used as a segmentation model for future VBM studies. |
| 2413 | A modular RF coil platform for ex-vivo imaging of brain slices at 9.4T | |
1Dept. of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands, 2Lab Engineering & Instrumentation Department, Maastricht University, Netherlands, 3Scannexus, Maastricht, Netherlands |
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We present a modular 9.4T RF coil platform that can be used for imaging slabs of tissue as large as a sagittal section of a human brain (dia. 18cm), with a thickness of up to 2cm. The 23-channel receive array was designed with a layered printed circuit approach to ensure the coils’ decoupling and proximity to the sample and with on-coil, low-noise preamplifier circuits. A 7 channel, phased transmit array capable of parallel transmission (pTx) makes homogeneous excitation of a large range of samples possible. The high homogeneous contrast-to-noise acquisitions enabled by the coil will allow high resolution anatomical imaging at 9.4T. |
| 2414 | Head-to-head comparison of ferumoxytol and gadolinium-enhanced intracranial MRA at 7T vs. non-contrast TOF | |
1Neurology/AIRC, OHSU, Portland, OR, United States, 2Radiology/AIRC, OHSU, 3Siemens Medical, 4Neurology, OHSU, 5AIRC, OHSU, 6Neurology/Neurosurgery, OHSU |
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7T imaging of neurovasculature with TOF affords sub-millimeter resolution and can make it possible to visualize extremely small vessels such as the lenticulostriate arteries; however, TOF can be hampered by flow and pulsation artifacts. K-space reordering and the administration of a contrast agent can greatly reduce these artifacts while still allowing for small vessel conspicuity. We acquired gadolinium and ferumoxytol-based MRA alongside TOF in three patients and two radiologists rated vessel conspicuity and artifact. Artifacts were diminished with contrast, though there were no differences in artifact due to k-space reordering, and vessel conspicuity was high in all acquisitions. |
| 2415 | Bias in Aqueductal Cerebrospinal Fluid Flow Quantification Obtained using 2D PC-MRI | |
1Barrow Neurological Institute, Phoenix, AZ, United States, 2School of Biological Health and Systems Engineering, Arizona State University, Tempe, AZ, United States |
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This focus of this work was to determine the extent of RF saturation induced bias in cerebrospinal fluid flow quantification using 2D PCMRI. The velocity distribution within a flow region inherently biases the average estimate per voxel towards faster spins in that voxel. This effect was studied through variations in flip angle. The results indicated that higher flip angles would introduce more bias in the flow estimates, which could be a possible reason for the lack of consensus concerning the use of PCMRI in determining patient responsiveness to surgical interventions in NPH studies. |
| 2416
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Magnetic Resonance Neurography (MRN) in the abdomen: the feasibility of imaging the celiac plexus with motion-compensated 3D SHINKEI | |
1UMC Utrecht, Utrecht, Netherlands, 2Philips Electronics Japan, Tokyo, Japan |
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Recently, the 3D-SHINKEI (3D nerve-SHeath signal increased with INKed rest-tissue RARE Imaging) sequence was introduced for peripheral MR neurography. This method uses an improved Motion Sensitized Driven Equilibrium (iMSDE) prepulse to suppress muscle and slow flow signal, for improved visualization of peripheral nerves. Applying this method in the abdomen would provide the potential to image the celiac plexus, which is involved in various pain mechanisms, e.g. due to pancreatic cancer and other upper gastrointestinal malignancies. In this work, we show the feasibility of MRN of the celiac plexus in volunteers by using cardiac and respiratory motion-compensated 3D SHINKEI. |
| 2417
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Magnetic flux density comparisons between in-vivo TACS human Magnetic Resonance Electrical Impedance Tomography measurements and MRI-derived human computational models | |
1Arizona State University, Tempe, AZ, United States, 2University of Florida |
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actual current densities applied to the brain in neuromodulation therapies. MREIT can be used to determine actual current densities delivered to the brain by measuring Bz. Here we present Bz distributions resulting from trans-temporal current injection obtained from MREIT imaging during 10 Hz TACS in a healthy human subject. Comparisons of MREIT results to MRI-derived computational models suggested that actual contact areas between electrodes and scalp may be smaller than electrode surface areas, and in-vivo tissue conductivity values, particularly skin and skull, may be different than assumed. |
| 2418 | Altered microstructural integrity in patients with tuberous sclerosis complex revealed by whole-brain tract-specific analysis | |
1Institute of Medical Device and Imaging, National Taiwan University College of Medicine, Taipei, Taiwan, 2)Institute of Biomedical Engineering, National Taiwan University College of Medicine, Taipei, Taiwan, 3Department of Pediatrics, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan, 4Molecular Imaging Center, National Taiwan University, Taipei, Taiwan |
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To investigate whether the white matter tracts are altered in patients with tuberous sclerosis complex, we used whole-brain tract-specific analysis of diffusion spectrum imaging (DSI) data to measure the alteration of 76 major white matter tracts, and compared the property between 27 patients and 27 matched controls. As compared to the controls, patients showed significantly lower GFA in 13 tracts. The altered microstructural integrity of the white matter tracts in TSC supports the hypothesis of underlying microstructural changes in the brains of TSC. |
| 2419 | Dynamic ADC Change during Cardiac Cycle in Human Brain in Sleep State | |
1Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan, Kawazawa, Japan, 2East Medic Corporation, Kanazawa, Ishikawa, Japan, Japan, 3Department of Inspection, Japanese Red Cross Kanazawa, Japan, 4Department of Radiology, Kanazawa University Hospital, Kanazawa, Japan |
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The glymphatic system is a waste clearance pathway in brain. During sleep, the increase in the interstitial influx results in faster waste removal. Apparent diffusion coefficient (ADC) in brain significantly changed during the cardiac cycle, and this change (ΔADC) shows the degree of fluctuation in water molecules. Therefore, we analyzed fluctuation of water molecules in the brain of healthy subjects in awake and sleep states. Maximum ADC and ΔADC of the white matter increased in sleep state. Fluctuation analysis facilitates the noninvasive evaluation of the dynamic state of water movement in the brain in sleep state as a glymphatic MRI. |
| 2420 | The Nulling Signal Produced by Inversion Recovery for Gray Matter is Related to Neuronal Density in the Thalamic Subnuclei: A 7T MRI Study | |
1Neuroscience Research Institute, Gachon university, Incheon, Korea, Republic of, 2Department of Biomedical Engineering, Gachon University, 3Department of Neurology, Gachon University Gil Medical Center, Gachon University, 4Department of Radiological Sciences, Gachon University |
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The thalamus acts as a gateway to higher brain centers that are involved in cognition, sleep, arousal, as well as sensory and motor information 1–5. Additionally, changes in the thalamic subnuclei (TS) have been implicated in a number of neuropsychiatric disorders. In a postmortem study, the neuronal number as well as the total volume of the thalamus were significantly decreased in schizophrenic subjects or elevated in major depression subjects, especially in the medial dorsal nucleus 6,7. As a result, the ability to estimate neuronal density in the thalamic subnuclei (TS) using in-vivo imaging is highly desired. |
| 2421 | Automated T2 Relaxometry of the Hippocampus | |
1Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, United Kingdom, 2Epilepsy Society MRI Unit, Chalfont St Peter, United Kingdom, 3Translational Imaging Group, Centre for Medical Image Computing, UCL, London, United Kingdom |
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Hippocampal sclerosis (HS), the most common cause of refractory temporal lobe epilepsy, is associated with hippocampal volume loss and increased T2-signal. These can be identified on quantitative imaging with hippocampal volumetry and T2 relaxometry. Whilst hippocampal segmentation for volumetry has been automated, T2 relaxometry currently involves subjective manual delineation of regions-of-interest. In this work, we validate an automated technique for hippocampal T2 relaxometry and show in a group of healthy controls and patients with HS that a combination of hippocampal volume and T2 values can reliably distinguish the groups and that automated measurement is more reproducible than manual measurement. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2422 | Comparison of Susceptibility Weighted Imaging MRI implementations across vendors: Implications for multi-centre studies | |
1IXICO PLC, London, United Kingdom, 2Translational Imaging Group, CMIC, University College London, London, United Kingdom, 3Epilepsy Society MRI Unit, Chalfont St Pete, United Kingdom, 4Department of Computing, Imperial College, London, United Kingdom, 5UCL Institute of Neurology, University College London, London, London, United Kingdom, 6Department of Medical Physics and Bioengineering, University College Hospital, London, United Kingdom, 7Dementia Research Centre, University College London, London, United Kingdom, 8Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Chalfont St Peter, United Kingdom, 9Brain Repair & Rehabilitation, UCL Institute of Neurology, London, United Kingdom, 10Leonard Wolfson Experimental Neurology Centre, UCL Institute of Neurology, London, United Kingdom |
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Multi-centre, MRI, Susceptibility Weighted imaging, Brain, Clinical Studies |
| 2423 | A simple partial volume correction method for magnetization transfer ratio images | |
1Lysholm Department of Neuroradiolgy, National Hospital for Neurology and Neurosurgery, London, United Kingdom, 2Academic Neuroradiological Unit. Dept. of Brain Repair and Rehabilitation, University College London, United Kingdom, 3Sydney Neuroimaging Analysis Centre, Sydney, Australia, 4Academic Neuroradiological Unit. Dept of Brain Repair and Rehabilitation, University College London, United Kingdom, 5National Prion Clinic, National Hospital for Neurology and Neurosurgery, United Kingdom, 6MRC Prion Unit. Department of Neurodegenerative Diseases, UCL Institute of Neurology, United Kingdom |
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We here demonstrate how partial volume correction by linear regression in the style originally proposed for arterial spin labelling MRI can be used to perform a simple and effective partial volume correction for Magnetisation Transfer Ratio data. |
| 2424 | A Novel Expectation Maximization based Multi Voxel Spatial Regularization Algorithm with Stimulated Echo Contribution (MVSR-STE) for Multi Component Analysis of the Quantitative T2 Relaxometry | |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Klinik und Poliklinik für Neuroradiologische Diagnostik und Intervention, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany |
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Problem: The quantification accuracy of myelin water fraction mapping based on multi echo spin echo (MESE) T2 relaxometry is compromised due to high SNR requirement, along with the need to account for contributions from stimulated echo pathways. Methods: A novel expectation-maximization post-processing method, with convergence guaranty, is proposed, which accounts for stimulated contributions intrinsically, while simultaneously improving noise robustness by utilizing spatial correlation from 3D local neighborhood. Results & Conclusions: Results demonstrate improved quantifications as a result of the proposed algorithm. |
| 2425 | Gradient non-linearity effects on upper cervical cord area measurement from MPRAGE brain MRI acquisitions | |
1Department of Neurology, University of California San Francisco, San Francisco, CA, United States, 2Department of Neurology, Brigham and Women’s Hospital, United States, 3Department of Neurology, The Johns Hopkins University, United States, 4Department of Brain and Behavioral Science, Univeristy of Pavia, Italy, 5Yale University, School of Medicine, United States, 6Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, United States, 7Department of Neurology, University of Toronto, Canada, 8Department of Neurology, University of Southern California, United States, 9Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation, United States, 10Advanced Imaging Research Center, Oregon Health & Science University, United States, 11Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, United States, 12Department of Neurology, Cedars-Sinai Medical Center, United States, 13Department of Radiology, University of California San Francisco, United States |
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Upper cervical cord area (UCCA) is strongly associated with physical disability in patients with multiple sclerosis, particularly in progressive stages of disease. Standard brain high-resolution 3D T1-weighted acquisitions that include the upper cervical cord can be used to provide estimates of UCCA. Depending on subject positioning in the scanner, gradient non-linearity can introduce up to 10% variability in UCCA measurements from volumetric brain MPRAGE scans. In planning a study, use of 3D correction methods provided by the scanner vendors seems optimal. Alternatively, to retrospectively correct data, we propose methods based on a phantom acquisition or normalization with vertebral body diameters. |
| 2426 | Evaluating White Matter Changes in Amyotrophic Lateral Sclerosis from T1-weighted MRI using 3-D Texture Analysis | |
1Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada, 2Department of Computing Science, University of Alberta, 3Division of Neurology, University of Alberta |
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Amyotrophic lateral sclerosis is a fatal neurodegenerative disease of the motor system with substantial disease burden in white matter. Clinical MRI studies are used only to exclude diagnoses of symptom-mimicking neurological disorders. We propose that texture analysis performed on structural MRI can provide a surrogate marker for subtle white matter changes that are observed in ALS. This study shows significant correlations between texture features from T1-weighted imaging and diffusion measures such as fractional anisotropy and mean diffusivity. These texture features also demonstrated significant differences between ALS and controls and can potentially be used clinically for diagnosis and disease monitoring. |
| 2427 | Impact of the topology of brain microbleeds on the structural brain network | |
1Department of Diagnostic Radiology, The University of Hong Kong, HKSAR, People's Republic of China, 2The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, HKSAR, People's Republic of China, 3Department of Medicine, The University of Hong Kong, HKSAR, People's Republic of China, 4Li Ka Shing Faculty of Medicine, The University of Hong Kong, HKSAR, People's Republic of China |
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We aim to investigate the effect of the topology of brain microbleeds (BMBs), lobar (n = 32) versus deep/infratentorial (n = 31), on structural brain network in patients with TIA or first-time stroke. Our results demonstrated that the efficiency of the local and global networks of both BMB cohorts were lower compared to controls (n = 31), and that only the load of the patients with lobar BMBs was strongly associated with decrease in the efficiency of local and global networks independent of vascular risk factors. These findings suggested that lobar and deep BMBs likely have distinct pathophysiological underpinnings. |
| 2428 | A Method for Quantification of T1 in Multiple Sclerosis Lesions | |
1Northwestern University, Evanston, IL, United States, 2University of Chicago |
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The development of multiple sclerosis lesions appear as different contrast mechanisms on the different MR imaging scans. In T1 weighted images, these evolve into hypointense lesions and representative of demyelination. In this study, we propose a method of quantifying T1 values using retrospective data of T1 weighted images, and apply this method to investigate potential trends of T1 changes in multiple sclerosis patients across time. We look at four patients imaged at three time points across 12 months, and find that an increase in T1 of lesions may be a trend. |
| 2429 | Distinct and common gray matter volume and cortical thickness abnormalities between non-comorbid medication-naive patients with major depressive disorder and social anxiety disorder | |
1Department of Radiology,West China Hospital of Sichuan University, Huaxi MR Research Center (HMRRC), Chengdu, People's Republic of China |
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An overlap of diagnosis frequently occurs between major depression disorder (MDD) and social anxiety disorder (SAD) and few studies directly compare neuroanatomical abnormalities in the two disorders. Pure MDD patients (n = 37), pure SAD patients (n = 24) and healthy controls (n = 41) underwent T1-weighted magnetic resonance imaging (MRI). Gray matter volume and cortical thickness were compared in the three groups. The main findings of this study were that (i) MDD and SAD patients shared common neural substrates in frontal-subcortical circuits; and (ii) MDD patients manifested more widespread brain structure alterations than SAD patients. |
| 2430 | Robust and automatic spinal cord detection on multiple MRI contrasts using machine learning | |
1NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montréal, QC, Canada, 2Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada, 3Aix Marseille Univ, CNRS, CRMBM, Marseille, France, 4APHM, Hôpital de la Timone, Hôpital de la Timone, Pôle d’imagerie médicale, Marseille, France, 5Montreal Heart Institute, Montréal, QC, Canada, 6Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, QC, Canada |
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Detecting the spinal cord on a large variety of MRI data is challenging but essential for the automation of quantitative analysis pipelines. For the past few years, machine learning algorithms have outperformed most unsupervised image processing methods. The present study investigates the performance of two different machine learning algorithms, Convolutional Neural Networks (CNN) and Support Vector Machine (SVM), on MRI data from different vendors, with a variety of pathology, contrast, resolution and FOV. Results suggest strong performance of the CNN approach, opening the door to application in multi-center analysis pipelines. |
| 2431 | Microstructural alterations in patients after liver transplantation and treated with calcineurin inhibitors – a quantitative MRI study | |
1Institute for Neuroradiology, Hannover Medical School, Hannover, Germany, 2Department of Neurology, Hannover Medical School, Hannover, Germany, 3Clinic for Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany |
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With the aim to evaluate possible brain microstructural alterations associated with calcineurin inhibitor (CNI) therapy, ninety patients after liver transplantation (OLT) treated with different doses of CNI and 32 gender- and age-adjusted healthy volunteers were studied with quantitative MRI (qMRI). T1, T2, T2*, Proton density (PD) and phase changes (derived from susceptibility-weighted imaging, SWI) were measured in 18 brain regions (regions of interest, ROIs). The values were compared between the groups of patients and the controls, which showed significant differences between the groups, indicating alterations of brain microstructure in patients after OLT. |
| 2432 | Increased Anisotropy as Possible Compensatory Plasticity of Ventral Thalamic Nuclei to Gait Disturbance in Patients with Idiopathic Normal Pressure Hydrocephalus | |
1Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, 2Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan, 3Translational Imaging Research Center, College of Medicine, Taipei Medical University, Taipei, Taiwan, 41Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan, 5Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan, 6Graduate Institute of Biomedical Electrics and Bioinformatics, National Taiwan University, Taipei, Taiwan, 7School of Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, Taiwan, 8Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan |
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This study allows improved localization of sensorimotor-related thalamic nuclei providing non-invasive evaluation of the microstructural changes of thalamus after iNPH, which may have a potential to contribute to early diagnosis and better prognosis prediction in the patients. |
| 2433 | Effects of coil combination algorithms on Quantitative Susceptibility Mapping | |
1NMR Unit, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 2Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, Hannover, Germany, 3A. A. Martinos Center for Biomedical Imaging and Department of Radiology, Harvard Medical School, Boston, MA, United States |
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Quantitative Susceptibility Mapping is an imaging technique for obtaining information of the magnetic susceptibility from phase images. If the phase information is obtained from a coil composed of multiple receive elements (coil array), the resulting images need to be combined. This step is non-trivial, and several algorithms, with different performances, have been proposed. Here we compare two different coil combination algorithms: the adaptive combine method and a recently proposed extension of ESPIRiT. For each, we compared both single subject and group-averaged QSM maps, where we observed that the results are sensitive to the method used for coil combination. |
| 2434 | IMPROVEMENT OF TOF-MRA IMAGE RECONSTRUCTION FROM UNDERSAMPLED DATA BY HEURISTIC MODIFICATION | |
1Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan, 2Human Brain Research Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan, 3Department of Systems Science, Graduate School of Informatics, Kyoto University, Kyoto, Japan |
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We study a heuristic modification of the NESTA algorithm for compressed sensing reconstruction of TOF-MRA images, where at each iteration the calculated k-space data are replaced with the original (acquired) data wherever the latter are available. We compared the modified method with the original method. In qualitative visual analysis, reconstructed images from the modified method were a little noisier but with better vessel signal delineation. In quantitative analysis, the modified method as compared with the original method marked higher rVBR values in lower sampling ratio, and caused no image degradation in higher sampling ratio. The modified method therefore provides a viable option in improving reconstruction of the NESTA algorithm for TOF-MRA undersampled data. |
| 2435 | COMPARISON OF BRAIN ATROPHY MEASURES FOR CLINICAL USE IN MULTIPLE SCLEROSIS | |
1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2R&D icometrix Leuven Belgium, Leuven, Belgium, 3Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy, 4Department of Radiology, Hospital Universitari Vall d'Hebron, Barcelona, Spain, 5Centre d'Esclerosi Múltiple de Catalunya (Cemcat), Department of Neurology/Neuroimmunology, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain, 6Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom |
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Aim of this study was to test two available methods (FSL-SIENAx/SIENA and Icometrix-MSmetrix) used for brain atrophy estimation on MR images of multiple sclerosis (MS) patients for a future clinical use. The accuracy and precision of these methods, as well as their main steps, were evaluated on 3D-T1 and 3DT2-FLAIR sequences of a simulated dataset, MRI of MS patients acquired at different scanners, field strengths, and on longitudinal dataset. From the comparison, SIENAx/SIENA showed a worst image registration, brain extraction and higher dependence on image acquisition quality than MSmetrix software. FSL pipelines showed better accuracy for cross-sectional and longitudinal analysis. |
| 2436 | A SEMI-AUTOMATIC METHOD TO SEGMENT MULTIPLE SCLEROSIS LESIONS ON FLAIR 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, 3Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy |
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Aim of the study was to adapt and evaluate on FLAIR images a recently developed semi-automatic method for segmentation of hyperintense multiple sclerosis (MS) lesions on dual-echo (DE) PD/T2-weighted MRI. FLAIR MRI scans were obtained from 17 clinically isolated syndromes patients on a 1.5T scanner. The method was based on a region growing approach initialized by manual identification of lesions. The stop condition was formulated combining intensity and edge detection constraints. High similarity with the manual segmentation (the gold standard) was found, as well as a low misclassification of lesion voxels. Operator time required for lesion segmentation was importantly reduced. |
| 2437 | Selecting parcellation schemes for regional cortical thickness estimations using a machine learning approach | |
1Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, 2Department of Electrical Engineering, National Sun Yat-sen University, Taiwan |
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In this study, we present a systematic approach to derive effective MR biomarkers of cerebral cortical thickness using machine learning methods and a large-scale database. Three neuroanatomical parcellation schemes for assessing region cortical thickness were compared. The results supported using the Desikan–Killiany atlas1 of FreeSurfer produced robust results of age and gender predictions in normal subjects. |
| 2438 | Fully automated morphometric brain volume extraction vs FreeSurfer | |
1University of Newcastle, Callaghan, Australia, 2Princess Alexandra Hospital, Woolongabba, Australia, 3Siemens Healthcare, Macquarie Park, Australia, 4Siemens Healthcare, Lausanne, Switzerland |
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Brain architecture has been shown to change with different disease processes and this can be quantitatively measured using automated brain segmentation methods. FreeSurfer is a validated automated brain morphometry analysis method but requires time-consuming post-processing and is computationally complex. Fully automated prototype brain morphometry post-processing is available on our scanner, which generates brain morphology data at the end of the sequence acquisition and doesn’t require manual post-processing. This study confirms that this prototype software yields brain morphology data that is highly correlated to FreeSurfer for major brain regions. Therefore, it can be used to investigate biomarkers of brain atrophy in research and clinical research arenas. |
| 2439 | A patch-based method for lesion in-painting in the spinal cord | |
1Translational Imaging Group, CMIC, Dep. of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 2UCL Institute of Neurology, Queen Square MS Centre, University College London, London, United Kingdom, 3Department of Brain and Behavioural Sciences, University of Pavia, Italy, 4Brain MRI 3T Mondino Research Center, C. Mondino National Neurological Institute, Italy |
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Multiple Sclerosis lesions can impair most automated image-processing pipelines. They can be present with different sizes, contrasts and shapes and at multiple locations across the central nervous system. Whilst lesion-filling is often a required pre-processing step in the analysis of brain MR images, its potential utility in spinal cord imaging remains unexplored. This study introduces a method for in-painting lesions in the spinal cord and demonstrates its efficacy for improving the results of spinal cord MR image analysis. |
| 2440 | Patient-specific 3D Printable Anatomical Brain Models from a Web App | |
1Translational Imaging Group, CMIC, Dep. of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom |
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The process for obtaining 3D printed models from patient-specific brain Magnetic Resonance Imaging (MRI) datasets remains tedious for non-computer scientists, despite the availability of various open-source image segmentation software and the current affordability of 3D printers. In this work, we present a web app that takes advantage of cloud computing technologies to propose a practical and straigntforward system for anyone to upload brain MRI datasets and automatically receive corresponding patient-specific 3D printable models. Using our tool requires absolutely no specific installation or configuration. |
| 2441 | Automated Brain Tissue and Myelin Volumetry Based on Quantitative MR Imaging with Variable In-plane Resolutions | |
1Radiology, Juntendo University, Tokyo, Japan, 2Radiology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan, 3Radiological Sciences, Tokyo Metropolitan University Graduate School of Human Health Sciences, Tokyo, Japan |
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Automated brain tissue segmentation and volumetric assessment based on the quantification of the T1 relaxation time, T2 relaxation time and the proton density (PD) have demonstrated good accuracy and reproducibility. Recently, an automated myelin volume calculation based on quantitative imaging also has been introduced. This study showed that automated brain tissue and myelin volumetry based on quantitative MR imaging with lower in-plane resolutions have good repeatability and can be obtained in short acquisition times, which is beneficial for follow-up study. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2442 | Excitatory Repetitive Transcranial Magnetic Stimulation (rTMS) Induces Contralesional Cortex-Cerebellar Pathways to Facilitate Motor Recovery after Acute Ischemic Stroke | |
1Department of Radiology, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People's Republic of China, 2State Key Laboratory of Brain and Cognitive Science, Beijing MR Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, People's Republic of China, 3Department of Interventional Radiology, China Meitan General Hospital, Beijing, People's Republic of China, 4Department of Radiology, Department of Radiology, School of Medicine, University of Pennsylvania, Philadelphia, PA, United States, 5Department of Neurology, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, People's Republic of China |
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In this study we used the Diffusion Tensor Imaging method to assess motor pathway changes in acute ischemic stroke patients after high frequency repetitive transcranial magnetic stimulation (rTMS). We found that the excitatory rTMS applied to the ipsilesional primary motor cortex induced the contralesional cortex-cerebellar loop to facilitate motor recovery. The result is consistent with those of our former studies and gives us a clue to understand the therapeutic mechanism of rTMS for early stroke patients. |
| 2443 | Detection of cerebral microvascular lesions using 7 T MRI in patients with neuropsychiatric systemic lupus erythematosus | |
1Division of Pulmonary Medicine,Allergy,and Rhematology,Department of internal Medicine, Iwate Medical University, morioka, Japan, 2Pulmonary Medicine,Allergy,and Rheumatology, Iwate Medical University, Morioka, Japan, 3Ultra-High Field MRI and Department of Radiology, Iwate Medical University, morioka, Japan |
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We investigated whether high-resolution images obtained using ultrahigh field MRI at 7 T can detect microcerebrovascular lesions in patients with neuropsychiatric systemic lupus erythematosus (NPSLE) that have never been detected by conventional MRI. We prospectively examined 20 patients with SLE, including five with NPSLE, using a 7 T MRI scanner. On the high-resolution T1WIs obtained at 7 T, minute punctate/linear hyperintense lesions in subcortical and/or cortical areas were found in four (80%) NPSLE patients and one (7%) non-NPSLE patient. High-resolution T1WIs obtained at 7 T can detect minute lesions, indicating intracerebral microvascular lesions in patients with NPSLE. |
| 2444 | Acceleration-selective Arterial Spin Labeling (AccASL) MR Angiography of Brain Arteriovenous Malformation | |
1Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 2Philips Electronics Japan, Tokyo, Japan |
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In the present study, we demonstrated the clinical utility of acceleration-selective arterial spin labeling (AccASL) MR angiography (MRA) in brain arteriovenous malformations (AVMs). AccASL-MRA significantly improved the visualization of AVM in comparison with time-of-flight (TOF)-MRA. AccASL-MRA could detect the nidus and draining veins in all patients. In particular, the detection of deep venous drainage by AccASL-MRA led to the accurate Spetzler-Martin grading. AccASL-MRA could serve as a noninvasive tool to evaluate brain AVMs without the use of contrast agents. |
| 2445 | Cerebral Blood Flow of CASL Perfusion Imaging to Predict Neurobehavioral Outcome in a Murine Model of Subarachnoid Hemorrhage | |
1Department of Preclinical Evaluation, Institute of Development, Aging and Cancer (IDAC), Tohoku University, Sendai, Japan, 2Research Institute for Brain and Blood Vessels-AKITA, Akita, Japan, 3Department of Nuclear Medicine and Radiology, IDAC, Tohoku University, Sendai, Japan, 4Graduate School of Psychology, Kobe Shoin Women’s University, Kobe, Japan |
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Early brain injury/ischemia is a recent therapeutic target of subarachnoid hemorrhage (SAH) that contributes to triggering delayed cerebral ischemia (DCI) [1]. However, little is known about the role of cerebral blood flow (CBF) and neurobehavioral profiles at acute stage on functional outcome of the rodent model to simulate clinical severity early after SAH. The present study demonstrated the feasibility of MRI-based CBF measurements using the continuous arterial spin labeling (CASL) perfusion images for precise grading of the severity in a murine model of endovascular perforation model of SAH. |
| 2446 | Relationship between venous congestion and susceptibility of collecting veins: an in-vivo QSM study with developmental venous anomaly | |
1Radiology, Seoul St. Mary's hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea, Republic of |
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A developmental venous anomaly (DVA) is a common vascular malformation, with an unusual-locating collection vein and fine venous structures draining into it. Occasionally, abnormal signal intensity is combined in draining area of DVA, which is a result of venous congestion. In this work, we explored the magnetic susceptibility of draining veins in DVAs with and without venous congestion. DVAs with venous congestion showed higher susceptibility values in collecting veins than those without venous congestion. Using 3D GRE and QSM, we could assess the oxygen metabolism of brain tissue with venous congestion. |
| 2447 | Modulation of the peri-infarct neurovascular function by Beta-Hydroxybutyrate | |
1Medical biophysics, Sunnybrook Research institute, Toronto, ON, Canada, 2Yale University, CT, United States, 3Sunnybrook Research Institute, 4Sunnybrook Research Institute, ON, Canada, 5Sunnybrook Research Center, ON, Canada, 6ON, Canada, 7Krembil Research Intitute, Toronto, ON, Canada |
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In view of the failure of neurocentric treatments for ischemic stroke, this work examines a pleiotropic modulation of the neurogliovascular unit exerts beneficial effects in the treatment of brain stroke. Oxydative metabolism of glucose in the peri-ischemic tissue has potentially detrimental effects on tissue; in contrast, ketones’ metabolism - in light of the reduced amount of oxygen required - provides a safer alternative. We employed functional CASL, in situ electrophysiology, and biochemical analysis to show short-term benefits of early administration of β-Hydroxybutyrate to metabolically challenged brain tissue following focal ischemia. |
| 2448 | White Matter Hyperintensities Segmentation and Stereological Bias Correction On Clinical MRIs | |
1Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, 2Division of Cardiology and Radiology, Children's Hospital Los Angeles, Los Angeles, CA, United States |
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White matter hyperintensities are lesions in the brain that exhibit high signal intensity on T2-weighted FLAIR images. In this study, we designed a seed-based segmentation method of these lesions from T2-weighted images of 1.3mm axial resolution, utilizing the local gradient field on a breadth-first search scheme as well as level thresholding and smoothing for false-positive reduction. Additionally, since clinical MRIs are at lower resolution of 1x1x5mm, we modeled the relationship between lesion cross-sectional radius and its true volume with a cubic polynomial fit to correct for stereological bias. |
| 2449 | 4D Flow MRI analysis of cerebral blood flow before and after EC-IC bypass surgery | |
1Radiology, Nippon Medical School, Tokyo, Japan, 2Radiology, Nihon University School of Medicine, Tokyo, Japan, 3Healthcare, Philips Electronics Japan, Tokyo, Japan |
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The purpose of this study was to demonstrate the feasibility of 4D Flow MRI to monitor the change of flow dynamics between before and after extracranial-intracranial (EC-IC) bypass surgery. We enrolled 14 patients who underwent EC-IC bypass. In all, 5 patients underwent radial artery graft (RAG) bypass and 9 patients underwent superficial temporal artery (STA) bypass. All patients underwent 4D Flow MRI preoperatively and 3 weeks after surgery. We measured blood flow volume (BFV) of bilateral internal carotid artery (ICA), basilar artery (BA), and EC-IC bypass artery using 4D flow MRI. Post/pre-operative BFV ratio of contralateral ICA was statistically higher in patients with the RAG bypass group than in those with the STA bypass group (1.28±0.26 in RAG bypass group vs 0.94±0.14 in STA bypass group, p<0.01). 4D Flow MRI could assess comprehensive flow dynamics of EC-IC bypass surgery. It is feasible to clarify the change of contribution from each artery. |
| 2450 | The role of serotonin in cerebral blood flow and oxygen metabolism in migraine | |
1Radiology, University of Californai San Diego, La Jolla, CA, United States, 2Neurology, Scripps Clinic, La Jolla, CA, United States |
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We examined the CBF and CMRO2 changes that accompany menstrual migraine, and evaluated the response to sumatriptan to determine the role of serotonin in migraine pathophysiology. Migraine is accompanied by a decline in global CBF and CMRO2 that appears to be serotonin-mediated. There is also a decline in stimulus-dependent CBF to a visual stimulus, that appears to also involve serotonin, but acts differently from the global responses. A decline in visual stimulus-dependent CMRO2 is not serotonin mediated, and appears to follow the normal variation in stimulus-dependent CMRO2 response that changes with normal menstrual cycle. |
| 2451 | Triple Magnetic Resonance Angiography (triple-MRA) for confirmation of obliteration following Gamma Knife Radiosurgery for Arterial-Venous Malformations of the brain | |
1The Gamma Knife Centre at Queen Square, National Hospital for Neurology and Neurosurgery, London, United Kingdom, 2Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, United Kingdom, 3Neuroradiology Unit, Department of Diagnostic and Pathology, University Hospital of Verona, Verona, Italy, 4The Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, United Kingdom, 5Medical Physics and Bioengineering, University College London Hospital, London, United Kingdom, 6Academic Neuroradiological Unit, Department of Brain Repair and Rehabilitation, Institute of Neurology, University College London, London, United Kingdom, 7C. J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, 8Radiology Unit, Department of Diagnostic and Pathology, University Hospital of Verona, Verona, Italy, 9Centre for Medical Imaging, University College London, London, United Kingdom, 10Department of Neuroscience, University Hospital of Verona, Verona, Italy |
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This study assesses whether a combination of three Magnetic Resonance Angiography (MRA) techniques, referred to as triple-MRA, can be used as an alternative to DSA for confirmation of AVM obliteration following GKR and to characterise residual AVMs in case of incomplete response. The follow up DSA and triple-MRA of twenty-four patients were independently reviewed by two observers regarding the presence/absence of a residual AVM. Triple-MRA consistently agreed with DSA regarding the absence or presence of residual AVMs and proved to be highly suitable for characterisation of residual AVMs. |
| 2452 | Application of 3D SPACE MRI on intracranial aneurysm: A preliminary study | |
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2Department of Radiology, Changhai hospital of Shanghai, 3Radiology Service, VA Medical Center, San Francisco |
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Most of the high resolution MRI(HRMRI) intracranial vessel wall studies on intracranial aneurysm are 2D or 3D non-isotropic technique with limitation of coverage and reconstruction. We applied pre- and post- 3D isotropic T1-weighted fast-spin-echo sequence (SPACE) methods on 16 patients with 21 stable intracranial aneurysms(4 patients follow up). Our studies showed that 3D T1-weighted high resolution SPACE can be used for evaluation of the vessel wall characteristics in patients with intracranial aneurysms, as well as changes in enhancement at follow up studies. Post-contrast SPACE images provide better image quality and improved diagnostic confidence. |
| 2453 | The feasibility of using whole-brain 3D high-resolution MRI to evaluate the therapeutic efficacy of medical therapy on symptomatic atherosclerotic plaques in the middle cerebral artery | |
1radiology, West China Hospital, Sichuan University, Chengdu, People's Republic of China, 2Radiology, West China Hospital, Sichuan University, Chengdu, People's Republic of China, 3Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, Los Angeles, United States |
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The stroke is a common cause of death. The technique of high-resolution magnetic resonance imaging (HR-MRI) has been used to depict the vessel wall. Our study aimed to evaluate thetherapeutic efficiency of the symptomatic atherosclerotic plaque in middle cerebral artery by 3D High-resolution MRI. And we compared the imaging and clinical symptom before and after the therapy. The diagnosis of the imaging is consistent with the clinical symptom. 3D High-resolution MRI is a potential imaging technology to evaluate therapeutic efficiency of atherosclerotic plaque in middle cerebral artery. |
| 2454 | Imaging findings in patients with pulsatile tinnitus using black-blood MRI: a retrospective study | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, People's Republic of China, 2Neurosurgery department of the general hospital of PLA, Beijing, People's Republic of China, 3Xuanwu Hospital, Capital Medical University, Beijing, People's Republic of China, 4Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, People's Republic of China, 5Department of Radiology, University of Washington, Seattle, United States |
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In this study, we used black-blood (BB) MRI to investigate and classify venous wall abnormalities among PT patients, and found that venous vessel wall anomalies played an important role in PT mechanism. Arachnoidal granulations overgrowth, congenital stenosis, double-lumen, arterio-venous fistula, mastoiditis and malformation were observed in this retrospective study. In conclusion, BB imaging has the potential to provide more pathological information and guide surgical treatment of PT, which is of great clinical value. |
| 2455 | Association of Atherosclerotic Plaque Characteristics between Intracranial and Extracranial Carotid Arteries in Symptomatic Patients: A 3D Multicontrast MR Vessel Wall Imaging Study | |
1Department of Radiology, Beijing Tsinghua Changgung Hospital, Tsinghua University, Beijing, People's Republic of China, 2Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China, 3Department of Radiology, University of Washington, Seattle, United States, 4Philips Research China, Philips Healthcare, Beijing, People's Republic of China, 5Department of Radiology, PLA General Hospital, Beijing, People's Republic of China |
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This study investigated the correlation between intracranial and extracranial carotid artery atherosclerotic disease in symptomatic patients. We found that extracranial artery disease showed larger plaque burden than intracranial artery disease. In addition, the number of extracranial plaques was found to be associated with intracranial plaque number and maximum wall thickness (MaxWT) and the extracranial carotid MaxWT was independently associated with intracraninal artery stenosis. The association of extracranial artery plaque number and MaxWT with severity of intracranial artery disease suggests that the plaque burden measurements in extracranial carotid arteries might be effective indicators for the severity of intracranial atherosclerosis. |
| 2456 | Comparison of two different measurement methods in evaluating basilar atherosclerotic plaque using high resolution MRI 3 T | |
1Radiology, Changhai Hospital of Shanghai, Shanghai, People's Republic of China |
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Evaluation of morphologic characterization of BA plaque (such as plaque area, stenosis rate and percent plaque burden) is significant and may guide treatment decisions in clinical setting. In this study, we employed the maximal lumen narrowing sites as the referenced sites to calculate morphologic parameters. This study aims to compare the Referenced and Self-referenced measurement method methods in assessing basilar atherosclerotic plaque employing dark blood HRMRI at 3 Tesla. The present study found Self-referenced method is more convenient and even better for evaluating BA plaque. |
| 2457 | Relationship between cerebral blood flow and water diffusion in the brain of misery perfusion model mice | |
1National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan, 2Fukushima Medical University, Fukushima, Japan |
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We have investigated degeneration of the nerve fibers in chronic cerebral hypoperfusion model mice using DTI. Simple t-tests indicated that there are significant differences in CBF between the control and occluded sides of the brain, but there was no significant difference for MD. However, analysis of covariance showed that MD was strongly correlated with CBF, and that there were significant differences in MD between the contra- and ipsilateral sides. The result suggests degeneration of the nerve fibers due to chronic hypoperfusion. It is also suggested that CBF-related signal changes might be important for pathological diagnosis with DTI. |
| 2458 | Arterial Spin Labeling Evaluation of Severity of Hypoperfusion in Symptomatic Intracranial Atherosclerotic Stenosis | |
1Radiology, Chinese PLA General Hospital, Beijing, People's Republic of China, 2Jincheng General Hospital, People's Republic of China, 3Beijing Tiantan Hospital, Capital Medical University, Beijing, People's Republic of China, 4GE healthcare China, Beijing, People's Republic of China |
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Multiple post labeling delay arterial spin labeling provide dynamic perfusion information in patients with intracranial artery atherosclerostic stenosis, and is of useful to study collatera circulation. In this study, two PLD ASL was used to evaluate the severity of hypoperfusion in patients with unilateral middle cerebral artery (MCA) stenosis and we found that the severity of hypoperfusion assessed by two PLD ASL was significantly correlated with collateral circulation and associated with recurrent ischemic stroke in these patients. |
| 2459 | The diagnostic utility of high-resolution 3D T1-weighted SPACE imaging in patients with intracranial vertebrobasilar dissecting aneurysms. | |
1RADIOLOGY, BEIJING TIANTAN HOSPITAL, CAPITAL MEDICAL UNIVERSITY, BEIJING NEUROSURGERY INSTITUTE, BEIJING, People's Republic of China, 2NEUROINTERVENTION, BEIJING TIANTAN HOSPITAL, CAPITAL MEDICAL UNIVERSITY, BEIJING NEUROSURGERY INSTITUTE, BEIJING, People's Republic of China, 3MR Collaborations NE Asia, Siemens Healthcare, BEIJING, People's Republic of China |
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The purpose of this study is to investigate the application value of a 3D high-resolution fat-saturated (FS) T1 SPACE sequence for the diagnosis of intracranial vertebrobasilar dissecting aneurysm (VBDA). With sub-millimetric and nearly isotropic acquisition, the 3D T1-SPACE sequence demonstrated good sensitivity and specificity for the detection of the imaging features associated with VBDAs using a large coverage area and a thin slice thickness. |
| 2460 | Reduced cortical thickness in patients with sickle cell disease and a high pain burden: baseline results from the Prevention of Morbidity in Sickle Cell Anaemia trial | |
1Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, United Kingdom, 2School of Psychology, University of Southampton, Highfield, United Kingdom |
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Although acute vaso-occlusive pain crises are common in sickle cell disease (SCD), some patients also experience chronic daily pain. This study investigated cortical areas involved in pain processing in low-pain and high-pain groups of patients at baseline of a trial with a pain burden outcome. High-pain patients had significantly thinner cortex in the right anterior cingulate cortex, bilateral posterior cingulate cortex, bilateral precuneus and left primary motor cortex. This is the first study showing structural brain abnormalities in patients with SCD and a high pain burden; these data may provide potential biomarkers for longitudinal trials of treatment for chronic pain. |
| 2461 | White matter volume change of carbon monoxide intoxication: a 9-month follow-up study | |
1Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan, 2Electrical Engineering, National Taiwan University, 3Neurology, E-Da Hospital, 4Radiology, Kaohsiung Veterans General Hospital |
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Using automated segmentation, volume of brain tissues is assessed at around one week, one month, three months, and 9 months after CO exposure. Among all 17 patients (7 male, mean age: 42.7 yr) recruited in this prospective study, seven are diagnosed with delayed neuropsychiatric syndrome (DNS) and the other ten without. Our results indicate that the white matter volume of all DNS positive patients shows similar trends that it first increases at 1-month follow-up and then decreases, when other GM tissues remain the same. In addition, no volume change is observed in the group without DNS. |
| 2462 | Design of a 24-channel array for imaging Intracranial vascular wall at 3T | |
1Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen City, People's Republic of China, 2Department of Radiology and Biomedical Imaging, University of California San Francisco, CA, United States, 3UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, United States |
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Atherosclerosis is a major cause of ischemic stroke. In this study we build a 24-channel head coil array with a special designed coil arrangement to detect non-stenotic atherosclerotic plaques. We compare the 24-channel head coil with Siemens 32-channel coil. For imaging test, the g-factor maps of these two coil arrays are the same, which shows that the 24-channel coil has the same capability of paralleling imaging as the 32-channel coil, and SNR maps show that at the center of the phantom which corresponds to the intracranial region of the head, the 24-channel coil is as good as 32-channel coil. |
| 2463 | Intracranial plaque imaging using reduced field of view 3D fast spin echo | |
1GE healthcare MR Research China, Beijing, People's Republic of China, 2Wuhan Children Hospital, 3PLA Army General Hospital |
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In this study, the use use of reduced FOV CUBE is studied in comparison to full FOV CUBE as well as other common techniques. It was seen that CUBE sequences provide robust and superior image details and black blood effects, due to the advantageous 3D FSE acquisition. With only 1/4 of the FOV acquired, reduced FOV CUBE may complete the scan using half of the scan time (using twice Nex) while obtaining highly consistent results as FF CUBE. Reduced FOV CUBE may also reduce the motion related artifacts that may affect the homogeneity of the lumen area. |
| 2464 | Feasibility of highly accelerated Parallel Imaging of whole brain and neck vessel wall using a high SNR 32-channel coil on 3T | |
1Shenzhen Institutes of Advanced Technology, Shenzhen, People's Republic of China |
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Three dimensional whole brain and neck vessel wall imaging of high resolution facilities the imaging of intracranial and extracranial arteries in stroke patients. However, its clinical usage is hindered by long scan time. Using a 32-channel head and neck coil system specially designed for high SNR, this work investigated the feasibility of highly accelerated parallel imaging equipped with optimally selected uniform subsampling pattern based on 3D G-factor calculated from separate calibration data and joint sparsity based denoising at acceleration factor of 6. |
| 2465 | Assessment of cerebral perfusion autoregulation impairment – An experimental setup to quantify regional cerebral blood flow (CBF) in normal and head down tilt position | |
1Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 2Health Sciences Fabrication Shop, Department of Medicine,Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 3MRI Clinical and Translational Research Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 4Department of Psychiatry,Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 5Department of Orthopedics,Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States |
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Previous studies using Transcranial Doppler have shown that cerebral ischemia, head trauma, and cerebral perfusion pressure are associated with an impairment of the cerebral autoregulation (CA) and alteration of perfusion. However, simulating perfusion changes and quantifying them with higher specificity repetitively has been a challenge in clinics. We propose a clinical experimental setup for an MRI-based head down tilt protocol to study the CA by quantifying perfusion. We demonstrate local perfusion change results in healthy controls and a patient. |
| 2466 | PC-MRI OF CEREBRAL BLOOD AND CSF FLOW VERSUS INTRACRANIAL PRESSURE MONITORING IN HYDROCEPHALUS PATIENTS | |
1Departments of Medical Image Processing, BioFlowImage Laboratory, University Hospital of Picardie Jules Verne, AMIENS, France, 2Department of Internal Medicine and Gerontology, Toulouse University Hospital, Toulouse, France, 3Neurosurgical Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK., 4Department of Nuclear Medicine, CHU Toulouse, Purpan University Hospital, Toulouse, France, 5UMR 1214 – INSERM/UPS – TONIC Toulouse Neuro-Imaging Center, Toulouse, France, 6Departments of Neurosurgery, University Hospital of Toulouse, France |
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The neurosurgical guidelines recommend low invasive intracranial pressure (ICP) monitoring with infusion tests to detect CSF dynamics alteration. In this study, we investigate how PC-MRI could be helpful in intracranial flow investigations. Eighty-three patients suspected of active hydrocephalus underwent the conventional ICP investigations. All the patients had also the day before, a rapid and simple PC-MRI to assess their cerebral blood and CSF flows. We found that patients who presented altered CSF dynamics (observed by ICP monitoring) presented also the smallest cervical CSF oscillations in the population. PC-MRI brings easy, quick and non-invasive complementary information to investigate the craniospinal dynamic. |
| 2467 | Evaluating the clinical outcomes of patients with occlusion of the middle cerebral artery using susceptibility-weighted imaging | |
1Tianjin First Central Hospital, Tianjin, People's Republic of China, 2Radiology Department, Tianjin First Central Hospital, Tianjin, People's Republic of China |
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In this study, we used the susceptibility-weighted imaging and mapping technique (SWIM) to investigate the effect of vessel susceptibility when evaluating the severity of cerebral infarction to develop an early prognosis of patients with middle cerebral artery thrombosis. By analyzing thrombus length, thrombus susceptibility, clot burden score, and the Admission and Discharge National Institute of Health Stroke Scale (NIHSS) scores between groups divided by the presence or absence of a deep medullary vein (DMVs) and between groups divided by the presence or absence of an asymmetrically prominent cortical vein (APCVs), we found that patients with a DMVs or APCVs were not affected by the burden factors of a thrombus. Compared to an APCV, a DMV suggests the presence of a larger cerebral infarction and is associated with an increased discharged NIHSS score, indicating a poor short-term prognosis. |
| 2468 | Regional impaired cerebrovascular reactivity in migraine with and without aura in the interictal state: A pilot fMRI study | |
1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States, 2Biogen Inc., Cambridge, MA, United States, 3Division of Neuroradiology, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States, 4Department of Neurology, Massachusetts General Hospital, Boston, MA, United States |
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Ischemia within the posterior circulation has been proposed as a primary mechanism for migraine. Though, in-vivo studies have yet to fully elucidate the underpinnings of this mechanism. In the current study, angiography via time of flight (ToF) MR was used to identify potential structural deficits within the posterior circulation and hypercapnic BOLD fMRI was used to detect functional vascular defects by quantifying cerebral vascular reactivity (CVR). All three MoA subjects demonstrated a negative correlation in BOLD signal within the red nuclei during CO2 challenge whereas the three MA patients demonstrated CVR within the red nuclei that was similar to that of the control subjects. ToF MR angiography images from all MoA subjects showed hypoplasia of bilateral posterior communicating arteries (PCoA) in proximity of the circle of Willis. In contrast only one out of the three MA subjects showed PCoA hypoplasia on ToF images. Our findings of hypoplasia of posterior communicating arteries combined with abnormal CVR responses within the red nuclei provide both structural and functional evidence for differential vascular defects in the migraine samples studied. We suggest that the identified vascular deficits to impose vulnerability in midbrain blood supply that may likely contribute to the migraine pathophysiology. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2469 | Diffusion discriminant for mild cognitive impairment in Parkinson’s disease | |
1Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey, 2CorTechs Labs, San Diego, CA, United States, 3Hulusi Behcet Life Sciences Research Center, Istanbul University, Istanbul, Turkey, 4Department of Neuroscience, Istanbul University, Istanbul, Turkey, 5Institute of Psychology and Cognition Research, University of Bremen, Bremen, Germany, 6Department of Neurology, Istanbul University, Istanbul, Turkey, 7Department of Physiology, Istanbul University, Istanbul, Turkey |
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| 2470 | Predictive markers for Parkinson’s disease: A DTI based pattern classification study | |
1Electronics And Telecommunication, Symbiosis Institute Of Technology, Pune, India, 2Department Of Neurology, NIMHANS, India |
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This work presents a paradigm for predicting changes in pathology, supporting diagnosis and providing a potential biomarker for Parkinson’s disease. This is achieved by creating a high-dimensional support vector machine (SVM) based classifier that learns the underlying pattern of pathology using numerous atlas-based regional features extracted from Diffusion Tensor Imaging (DTI) data. For the dataset of 72 controls and 73 PD patients, we achieve a 10-fold cross validation accuracy of 72.8% and a testing accuracy of 78.5%. The top discriminative features included widespread patterns of mean diffusivity changes in PD. |
| 2471 | Analysis of the Substantia Nigra from Parkinson’s disease patients and control subjects using co-registered DTI and QSM data | |
1Medical Imaging, The Ottawa Hospital, Ottawa, ON, Canada, 2Radiology, University of Ottawa, Ottawa, ON, Canada, 3King Saud University, Riyadh, Saudi Arabia, 4Parkinson’s Disease and Movement Disorders Center, The Ottawa Hospital Research Institute, Ottawa, ON, Canada, 5Department of Medicine, University of Ottawa, Ottawa, ON, Canada |
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Different quantitative MRI techniques like Diffusion Tensor Imaging (DTI) and Quantitative Susceptibility Imaging (QSM) have been used to evaluate the substantia nigra (SN) in patients with Parkinson’s disease (PD). When multimodal MRI studies are applied to acquire several quantitative parameters the analysis of each of these datasets on an individual ROI basis can time consuming. In this study we are using a co-registration approach to a standard brain template for evaluating quantitative MR data (from DTI and QSM) in the SN of PD patients and controls. |
| 2472 | Quantifying nigral alterations in Parkinson's disease using neuromelanin and diffusion tensor imaging | |
1Radiology, Osaka University Graduate School of Medicine, Suita, Japan, 2Neurology, Osaka University Graduate School of Medicine, Suita, Japan |
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Dopaminergic neurodegeneration of the substantia nigra pars compacta (SNpc) in Parkinson's disease (PD) was evaluated quantitatively using both neuromelanin and diffusion tensor imaging. For the highly reproducible image analysis of the SNpc, an automatic region-of-interest selection method was developed with a voxel-based morphometric technique. Neuromelanin which can directly quantify dopaminergic neurodegeneration and mean diffusivity could differentiate PD patients from healthy controls and were correlated with each other. We conclude that a voxel-based evaluation using both neuromelanin and diffusion tensor imaging can reveal PD related neurodegenerative changes in the SNpc and may be a useful technique for quantitative diagnosis of PD. |
| 2473 | Peculiarities of brain activation during dominant hand tactile perception in lateralized Parkinson disease | |
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, Kiev, Ukraine |
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Parkinson's disease (PD) in mostly presented with asymmetrical motor symptoms. Disturbed sensorimotor integration and decrease of somatosensory cortex activation was previously shown. We analyzed brain activation and connectivity during the unilateral tactile stimulation in primary and non-primary hand lateralized PD patients. We have demonstrated steady contralateral S1 activation in PD. Primary hand tactile stimulation in primary hand lateralized PD patients evokes activation of primary and associative sensory, motor and executive nodes of the cortex. Mirror neuron system was activated in primary hand stimulation in PD patients. Tactile stimuli processing evokes increased connectivity of globus pallidus, premotor, prefrontal and parietal cortex. |
| 2474 | Cerebral Perfusion Correlates of MAPT and COMT Genotypes for Mild Cognitive Impairment in Parkinson’s Disease at 3T | |
1Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey, 2Hulusi Behçet Life Sciences Research Laboratory, Istanbul University, Istanbul, Turkey, 3Istanbul University, Institute of Experimental Medicine, Department of Neuroscience, Istanbul, Turkey, 4Institute of Psychology and Cognition Research, University of Bremen, Bremen, Germany, 5Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey, 6CorTechs Labs, San Diego, CA, USA, 7Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey, 8Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey |
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The purpose of this study is to investigate the cerebral perfusion correlates of microtubule-associated protein tau (MAPT) and catechol-O-methyl transferase (COMT) genotypes in Parkinson’s Disease with mild cognitive impairment (PD-MCI) and PD with normal cognition (PD-CN) using multi inversion time pulsed arterial spin labelling magnetic resonance imaging (pASL-MRI). Cerebral blood flow (CBF) and arterial blood volume (aBV) maps of patients were calculated by using general kinetic model and compared between different genotypes of PD-MCI and PD-CN. It was found that PD-MCI with H1/H1 genotype of MAPT gene had a lower cerebral perfusion than PD-CN with H1/H2 genotype. |
| 2475 | Disrupted topological organization of brain networks in early Parkinson’s disease (PD) subjects: Insights from Parkinson’s Progressive Markers Initiative (PPMI) dataset | |
1Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States |
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In vivo imaging that reliably captures the impact of the spreading pathology of Parkinson’s disease (PD), including its impact on both white and gray matter, remains elusive. In this study, we applied graph-theoretical techniques to multi-site diffusion-MRI data from a cohort of early PD-subjects in Parkinson’s Progressive Markers Initiative (PPMI) database. A disrupted topological brain organization in early PD-subjects was revealed with impaired network integration, segregation, global efficiency, and local efficiency. Furthermore, there was also |
| 2476 | Decreased axial diffusivity in early Parkinson’s disease subjects: Insights from Parkinson’s Progressive Markers Initiative (PPMI) dataset | |
1Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States |
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In vivo imaging that reliably captures the impact of the spreading pathology of Parkinson’s disease (PD), including its impact on both white and gray matter, remains elusive. In this study, we performed skeleton-wise analysis of multi-site DTI data from a cohort of early PD-subjects in Parkinson’s Progressive Markers Initiative (PPMI) database. Tract-based-spatial-statistics analysis revealed three clusters mainly located in corticospinal tract, and superior frontal gyrus that had a lower AxD in early PD-subjects suggesting DTI measures can be used to differentiate controls and early |
| 2477 | Environmental paraquat exposure and HFE genetics as factors in the development of Parkinson’s disease | |
1Neurosurgery, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, 2Radiology, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, 3Neural and Behavioral Sciences, The Pennsylvania State University - College of Medicine, Hershey, PA, United States |
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This work demonstrates a decrease in R2 within the ventral-nigral region of WT-HFE mice given paraquat injections. Furthermore, the decrease in R2 relaxation rate is not observed in the H67D-HFE mutation animals. This is the first demonstration that HFE mutations may be associated with a preservation of cellular loss in the substantia nigra and ventral-midbrain of Parkinson’s disease model animals. |
| 2478 | Effects of myelin changes in Parkinson's Disease on motor performance | |
1Department of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada, 2Pacific Pakinson's Research Centre, UBC Hospital, Vancouver, BC, Canada, 3Graduate Program in Neuroscience, University of British Columbia, 4Faculty of Medicine, Neurology, University of British Columbia, Vancouver, BC, Canada |
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Parkinson’s Disease is not normally associated with white matter changes in clinical MRI scans. Myelin water imaging was used to probe the white matter tissue integrity of mildly affected Parkinson’s Disease patients. Partial Least Squares regression was employed to find a multivariate relation between myelin water fraction along different white matter tracts and motor performance scores. We found association between myelin water fraction and rigidity, bradykinesia and tremor scores, linking changes in white matter tissue integrity to Parkinson’s Disease severity in motor scores. |
| 2479 | The Correlation Between Brain Iron Overload and Microstructure Change in Gray Matter Nucleus in Parkinson' s Disease | |
1first affiliated hospital of DaLian medical univercity, Da Lian, People's Republic of China, 2GE healthcare, People's Republic of China, 3first affiliated hospital of DaLian medical univercity, People's Republic of China |
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Enhanced Gradient Echo T2 Star Weighted Angiography (ESWAN) can sensitively shows iron overload in brain, especially gray matter; Diffusion Kurtosis Imaging (DKI) detects microstructure change of gray matter much better than Diffusion Tensor Imaging (DTI). PD patients has the iron overload in substantia nigra, and encephalatrophy on different levels--cortex, basal ganglia and midbrain. To emplore the relation between iron overload and microstructure change in extrapyramidal nuclei, we compared DKI and ESWAN parameters in PD and healthy control groups, and analysis the correlation between them. Found that there are some relations in substantia nigra, red nucleus and putamen in PD patients. |
| 2480 | Improved detection of grey matter atrophy in Parkinson's disease in a Chinese population using the Chinese2020 template | |
1Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, People's Republic of China, 2Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, Hong Kong, 3MR Collaboration, Northeast Asia, Siemens Healthcare, Beijing, People's Republic of China, 4Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China, 5Research Center for Medical Image Computing, Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, Hong Kong |
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The human brain differs significantly between different individuals, as well as between different demographics (i.e., age, gender, and race). The aim of the present study was to investigate the effectiveness of a Chinese brain template, i.e., Chinese2020, on the detection of grey matter (GM) alteration between patients with Parkinson’s disease (PD) and healthy controls (HC). The results of this study indicate that Chinese2020 was more representative of Chinese populations, which suggests that neuroimaging studies based on Chinese populations should be normalized to the Chinese brain atlas and that previous studies based on Chinese populations might need to be updated. |
| 2481 | Evaluation of Neuromelanin-MRI parameters and Volumetric changes with Parkinson’s Disease Progression | |
1Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal, 2Physics Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Lisbon, Portugal, 3Neurological Imaging Department, Hospital de Santa Maria - Centro Hospitalar Lisboa Norte, Lisbon, Portugal, 4Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal, 5Neurology Department, Hospital de Santa Maria - Centro Hospitalar Lisboa Norte, Lisbon, Portugal, 6Institute for Systems and Robotics / Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal |
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This study aimed to characterize changes in Neuromelanin-sensitive MR images with Parkinson’s Disease (PD) progression. The area of high signal intensity in the substantia nigra (SN) and its contrast ratio (CR) were assessed in early and late stage PD (LSPD) patients, and in healthy individuals. The relative hippocampus and midbrain volumes were also estimated from anatomical MPRAGE scans. The SN area was found to be markedly reduced in LSPD compared to early stages of the disease and so could be a useful tool to evaluate disease progression. The decrease in relative hippocampus volume could indicate cognitive impairment, characteristic of LSPD. |
| 2482 | Robust method for detection of small variations in relaxation parameters and free water content in substantia nigra of Parkinson's disease patients. | |
1Medical Imaging Physics, Institute of Neuroscience and Medicine, Forschungszentrum Jülich, Jülich, Germany, 2Department of Neurology, Faculty of Medicine, RWTH Aachen, JARA, Aachen, Germany, 3Nuclear Medicine and PET Center, Aarhus University, Aarhus, Denmark |
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Parkinson's disease patients were investigated in order to reveal changes inside region-of-interest – substantia nigra. 31 volunteers were scanned using a well-established, quantitative free water mapping protocol. The region-of-interest is too small to obtain reliable segmentation for region-based analysis. Therefore, statistical, voxel-wise analysis of registered quantitative maps was performed. It revealed a decrease in the metrics (free water content, T1, T2* and combination of all three) in the vicinity of substantia nigra. We conclude that the reduction in total free water content could be due to a disruption of the deep grey matter integrity. |
| 2483 | Functional connectivity depending on duration of parkinsonism before diagnosis of mild cognitive impairment in Parkinson Disease: focusing on the substantia innominata. | |
1Department of Radiology, Ewha Womans University School of Medicine, Seoul, Korea, Republic of, 2Department of Radiology, Veterans Health Service Medical Center, 3Department of Neurology, Yonsei University College of Medicine, 4Department of Radiology, Yonsei University College of Medicine, 5Department of Radiology, Ewha Womans University School of Medicine |
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Degenerative change in the nucleus basalis of Meynert, a group of cholinergic neurons in the substantia innominata (SI) of the basal forebrain, begins in the early stages of Parkinson disease (PD) and is known to be significantly correlated with cognitive performance. We found decreased resting state functional connectivity (rsFC) in bilateral frontal areas using bilateral SI mask as a seed and significant correlation between decreased rsFC and shorter disease duration before mild cognitive impairment was diagnosed in patients with Parkinson’s disease. Therefore, our results support that cholinergic deficit plays an important role in the acceleration of cognitive decline and conversion to PD dementia. |
| 2484 | Hierarchical organization of functional networks in patients with Parkinson’s Disease | |
1Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV, United States, 2University of Colorado Boulder, Boulder, CO, United States |
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Earlier studies using fMRI have shown the existence of a modular structure for different brain networks. However, no information exist about hierarchical modular structure of functional connectivity networks in patients with Parkinson’s disease(PD). Using percolation analysis, we found a shift in the hierarchical modular structure of functional connectivity networks in patients with PD. A shift in the modules in caudal-rostral direction in the PD group of motorically affected patients, alongside rearrangement of connector hubs and provincial hubs in PD patients was observed. Potential application of network properties observed here, as predictors of subsequent disease progression is currently being investigated. |
| 2485 | Neuromelanin and Volumetric Evaluation in Parkinson’s Disease Patients Carrying LRRK2 or GBA Mutations | |
1Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal, 2Physics Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Lisbon, Portugal, 3Neurological Imaging Department, Hospital de Santa Maria - Centro Hospitalar Lisboa Norte, Lisbon, Portugal, 4Clinical Pharmacology Unit, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal, 5Neurology Department, Hospital de Santa Maria - Centro Hospitalar Lisboa Norte, Lisbon, Portugal, 6Institute for Systems and Robotics / Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal |
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Previous studies in idiopathic Parkinson’s disease (iPD) have shown a reduction in the substantia nigra (SN) area hyperintense in Neuromelanin-sensitive MR images (NM-MRI). However, a few genetic mutations have been associated to PD. In this study we compared images obtained in iPD and in patients with LRRK2 or GBA mutations. Images were also acquired in control subjects. The area and contrast-ratio of SN in NM-MRI and the relative midbrain volumes were evaluated. There were no significant differences in volumes, but the SN area in NM-MRI accurately differentiated LRRK2 PD patients from controls. No differences were found between PD groups. |
| 2486 | A Behavioural and MRI Structural Study of Early Stage 6-OHDA Parkinson’s Disease Rat Model | |
1Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy, 2Laboratori Nazionali del Gran Sasso, Istituto Nazionale di Fisica Nucleare, L'Aquila, Italy, 3SPIN-CNR Institute, CNR, L'Aquila, 4Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy |
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We established the correlation between behaviour and functional structures in an early stage of 6-OHDA PD rat model. Behavioural data reveal that receptor sensitization develops few days after dopaminergic injury. The apomorphine-induced amplification of the motor asymmetry over time is paired to striatal shrinkage and alteration of the GM/WM area in the ipsilateral striatum, as revealed by immunohistology and ex-vivo high-resolution MRI analysis. |
| 2487 | Predominance of Odor-related Functional Decline in the Primary Olfactory Cortex of Early-stage Parkinson’s Disease | |
1Radiology, Penn State College of Medicine, Hershey, PA, United States, 2Neurology, Penn State College of Medicine, Hershey, PA, United States, 3Neural & Behavioral Sciences, Penn State College of Medicine, Hershey, PA, United States, 4Neurosurgery, Penn State College of Medicine, Hershey, PA, United States |
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The primary olfactory cortex (POC) responds to both odor-smelling and sniffing. It is not known if there are deficits in the sniffing-related or odor-related functional activities in the POC of early-stage Parkinson’s disease (PD). Here we report significant PD-related deficit in the odor-related POC activation, while the sniffing-related activation was not significantly affected. These results suggest that olfactory deficits in early-stage PD are mainly due to the breakdown of the bottom-up mechanism. In addition, our finding of a negative correlation between the UPDRS-3 score and the odor-related POC activation suggests a surrogate marker for the clinical severity in early-stage PD. |
| 2488 | Functional network remapping of the subthalamic nucleus in Parkinson's disease | |
1HMCS, NINDS, NIH, Bethesda, MD, United States, 2School of Biomedical Engineering, Fourth Military Medical University, Xi’an, Shaanxi, People's Republic of China, 3Neurology Department, Yale School of Medicine, New Haven, CT, United States |
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We modified a parcellation method to map the motor, limbic and associative territories within the subthalamic nucleus (STN). We further evaluated whether a remapping of the STN connectivity exists in Parkinson’s disease (PD) patients. Resting-state fMRI data were analyzed using independent component analysis and general linear model. In both groups, the motor area was identified in the posterior zone, while the limbic zone was more anteriorly located. The motor connections were altered in the PD patients. Our approach could be used for functional parcellations and for remapping of functional connectivity due to disease in brain areas with heterogeneous connectivity patterns. |
| 2489 | Which one is a better marker for the diagnosis of Parkinson’s disease: T1 MRI or DTI | |
1Department of Radiology and Biomedical Research Imaging Center (BRIC), University of North Carolina at Chapel Hill, Chapel Hill, NC, United States |
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Parkinson's disease (PD) is a common neurodegenerative disorder, which progresses slowly and affects the quality of life dramatically. In this paper, we use the T1 MRI and DTI data from the PPMI study to analyze the effect of each modality through investigating the brain regions, and determine which modality can be a better marker at diagnosing the disease. For this purpose, we propose a joint feature selection and max-margin classification framework, in which we select features that best benefit the classification scheme. Our results show that the brain structural connectivity studies using DTI leads to better results. |
| 2490 | An Imaging Progression Marker for Parkinson’s Disease: A 4-Year Multicenter Longitudinal Study of Substantia Nigra Free-Water | |
1Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States, 2Department of Biostatistics, University of Florida, Gainesville, FL, United States, 3Department of Psychiatry, Harvard Medical School, Boston, MA, United States, 4Department of Radiology, Harvard Medical School, Boston, MA, United States, 5Department of Neurology, University of Florida, Gainesville, FL, United States, 6Department of Neurosurgery, University of Florida, Gainesville, FL, United States, 7Center for Movement Disorders and Neurorestoration, University of Florida, Gainesville, FL, United States, 8Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States |
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We used a bi-tensor model to calculate free-water (FW) in the substantia nigra (SN) from diffusion MRI scans obtained from the Parkinson’s Progression Marker Initiative (PPMI) database with the goal of monitoring disease progression over 1 year and 4 years in Parkinson’s disease (PD). Results confirm previous single-site findings by showing an increase in FW in the posterior SN over 1 year in a large multi-site study, and extend the literature by showing that FW levels in this structure continue to increase over 4 years. |
| 2491 | Altered Functional Connectivity Density in Subtypes of Parkinson’s Disease: a Resting-State fMRI Study | |
1Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, P.R. China, Chongqing, People's Republic of China, 2Key Laboratory for Neuro Information of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054, P.R. China, People's Republic of China, 3Collaboration NEA, Siemens Healthcare Ltd., Shanghai, P.R. China, People's Republic of China |
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In the current study, combined functional connectivity density (FCD) and seed-based FC analyses were performed to fully characterize the abnormal brain networks in the two subtypes. Our findings obtained using a combination of FCD and seed-based FC analyses provide consistent evidence for that the network disorganization of the brains in the two PD subtypes were different.We also found that the FCD provided good discrimination between the AR and TD patients. These findings have important implications for understanding the neural substrates that underlie these disparate manifestations of PD. |
| 2492 | Longitudinal Volume Change of Hippocampal Subfields and Cognitive Decline in Parkinson's Disease | |
1Department of Radiology, Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China, 2Collaboration NEA, Siemens Healthcare Ltd., Shanghai, P.R. China, People's Republic of China, 3Collaboration NEA, Siemens Healthcare Ltd., Beijing, P.R. China, People's Republic of China |
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We try to find out the longitudinal volume change of different hippocampal subfields in patients with PD with and without cognitive decline using magnetic resonance image (MRI). Our result shows that there is cross-sectional and longitudinal regional atrophy of specific hippocampal subfields in PD, which becomes more severe and is further extended to the bilateral CA2-3 and CA4-DG subfields in patients with cognitive decline. These results corroborate neuropathological findings and add novel information about the involvement of the hippocampus in the cognitive dysfunction of PD. |
| 2493 | Comparison of MR spectroscopic imaging findings between different MAPT and COMT genotypes of cognitively normal or mild cognitively impaired Parkinson’s disease patients at 3T | |
1Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey, 2Hulusi Behcet Life Sciences Research Laboratory, Istanbul University, Istanbul, Turkey, 3Istanbul University, Institute of Experimental Medicine, Department of Neuroscience, Istanbul, Turkey, 4Institute of Psychology and Cognition Research, University of Bremen, Germany, 5Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey, 6CorTechs Labs, San Diego, CA, USA, 7Department of Physiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey, 8Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey |
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Microtubule-associated protein tau (MAPT) and catechol-O-methyltransferase (COMT) genotypes have been associated with cognitive impairment in Parkinson’s disease (PD). The aim of this study is to compare MR spectroscopic imaging findings between cognitively normal PD (PD-CN) or mild cognitively impaired PD (PD-MCI) patients with different MAPT and COMT genotypes at 3T. We observed a higher Ins/Cr in cerebral white matter of PD-MCI with MAPT H1/H2 genotype than PD-CN with MAPT H1/H1 genotype and a higher Cho/Cr in thalamus of PD-MCI with COMT Met/Met genotype and PD-CN with COMT Val/Val or Val/Met genotype than PD-CN with COMT Met/Met genotype. |
| 2494 | Preliminary findings of elevated iron deposition in the substantia nigra in patients with idiopathic Parkinson’s disease using a high iron content evaluation of quantitative susceptibility mapping | |
1Research, Magnetic Resonance Innovations, Inc., Detroit, MI, United States, 2Department of Medical Imaging, Saskatoon Health Region, 3Research, The MRI Institute for Biomedical Research, Detroit, MI, United States, 4Division of Neurology in the Department of Medicine, University of Saskatchewan, 5Department of Medical Imaging, University of Saskatchewan, Saskatoon, SK, 6Radiology, Wayne State University School of Medicine |
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Iron deposition in the brain has been implicated in neurodegenerative diseases like Parkinson’s Disease. We used quantitative susceptibility mapping to evaluate iron content in the substantia nigra and red nucleus in 18 patients with idiopathic Parkinson’s Disease (IPD). Susceptibility was calculated for whole structure and a thresholded high-iron region (RII) and compared with controls. We found that global and RII mean susceptibility higher in the substantia nigra compared with normals, and that the slope of RII susceptibility vs age is higher in IPD compared to normals which may suggest an increased rate of iron deposition at disease onset. |
| 2495 | Differential Diagnosis of Parkinson’s disease, Progressive Supranuclear Palsy and Corticobasal syndromes using machine learning and MRI | |
1MRC Cognition and Brain Sciences Unit, Cambridge, United Kingdom, 2Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom |
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In this study we combined machine learning with MRI for the differential diagnosis of three movement disorders: Parkinson’s disease (PD), progressive supranuclear palsy (PSP) and degenerative corticobasal syndrome (CBS). We compared the performance of such approaches when using T1-weighted and diffusion MRI, as well as different methods for feature extraction. Our results suggest that such methods could be used in the future to aid the differential diagnosis of PSP, CBS and PD, in conjunction with clinical assessment, with diffusion MRI data providing the most promising results. |
| 2496 | Empirical Mode Decomposition and Amplitude Characteristics of Resting-State Networks in Parkinson’s Disease | |
1Cleveland Clinic Lou Ruvo Center for Brain Health, LAS VEGAS, NV, United States, 2University of Colorado Boulder, Boulder, CO, United States, 3University of Management & Technology, Lahore, Pakistan |
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In this project, amplitudes of low-frequency fluctuations in resting-state fMRI data of subjects with Parkinson’s disease (PD) are studied and compared with matched normal controls. Empirical Mode Decomposition (EMD) is used to decompose the natural occurring frequency bands of major networks important in PD. The novelty of our approach lies in the data-adaptive decomposition of fMRI data using EMD, and identification of resting-state networks based on amplitude characteristics of intrinsic modes. |
| 2497 | Extensive cortical involvement in patients with Huntington’s Disease as measured from diffusion MRI | |
1Medical Imaging and Radiological Sciences, Chang-Gung University, Taoyuan City, Taiwan, 2Neurology, Chang Gung Memorial Hospital, Linkou, Taoyuan City, Taiwan, 3Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou, Taoyuan City, Taiwan |
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Huntington’s Disease (HD) is a neurodegenerative disease would result in atrophy in basal ganglia especially in caudate nucleus and putamen in the early stage of the disease. The cortical parcellation algorithm was applied to evaluate the cortical involvement in the patients with HD by using diffusion MRI and compared with voxel based morphometry. The mean diffusivity is feasible in the brain of patients with HD, which is more sensitive than the morphometric changes. Therefore mean diffusivity could be a potential image based biomarker for monitoring HD progression. |
| 2498 | Functional connectivity disturbances in prodromal Huntington’s disease predict future cognitive decline | |
1Imaging Institute, The Cleveland Clinic, Cleveland, OH, United States, 2Lou Ruvo Center for Brain Health, The Cleveland Clinic, Cleveland, OH, United States, 3Department of Radiology, University of California, San Diego, La Jolla, CA, United States, 4Research Service, VA San Diego Healthcare System, San Diego, CA, United States, 5Carver College of Medicine, The University of Iowa, Iowa City, IA, United States, 6BrainDataDriven, Milwaukee, WI, United States |
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This study investigates intrinsic functional connectivity of the dorsal caudate in prodromal Huntington’s disease participants. We find that connectivity to the left caudate increases as estimated time to a manifest diagnosis decreases, and that stronger connectivity between the right middle frontal gyrus and left caudate is predictive of future cognitive decline. |
| 2499 | Deep grey matter T2 relaxometry at 3T in Huntington’s disease | |
1Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery. UCL Hospitals NHS Foundation Trust, London, United Kingdom, 2Academic Neuroradiological Unit. Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom, 3Huntington's Disease Centre, UCL Institute of Neurology, London, United Kingdom |
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Iron levels in the basal ganglia in Huntington’s disease (HD) have been previously investigated at 3T with MRI using magnetic field correlation imaging, T2*, quantitative susceptibility mapping (QSM), as well as T2 relaxometry mostly at lower fields of 1.5T or less. We performed T2 mapping at 3T in a group of pre-HD (n=10) and HD patients (n=11) to investigate its association with Disease Burden Score and structural measures (caudate volume) of disease load. We found significant correlations between T2 and disease progression measures in nucleus accumbens, putamen and pallidum. |
| 2500 | Automated Volumetry-based Morphometry in Postural Instability Gait Disorder | |
1Singapore General Hospital, Singapore, Singapore, 2Advanced Clinical Imaging Technology, Siemens Healthcare HC CEMEA SUI DI PI, Lausanne, Switzerland, 3Department of Radiology, University Hospital (CHUV), Lausanne, Switzerland, 4LTS5, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 5Advanced Clinical Imaging Technology, Siemens Healthcare HC CEMEA SUI DI PI, Singapore, Singapore, 6National Neuroscience Institute, Singapore |
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Postural instability gait disorder (PIGD) subtype in Parkinson's disease (PD) is a major cause of morbidity. We quantified whole-brain structural changes in PIGD patients, PD patients and controls using an automated volume-based morphometry algorithm that is objective and reproducible. Compared to PD and controls, PIGD subgroup demonstrated a significant decrease in brain and globus pallidus volume, as well as grey matter content in both caudate and thalamus; but an increase in ventricular size, abnormal white matter volume and relative caudate size. MRI findings also correlate with gait imbalance severity in PIGD, suggesting a mechanism of temporal differences in segmental volume loss. |
| 2501 | Measuring exercise-induced cerebrovascular changes in Huntington's Disease using arterial spin labelling (ASL) fMRI | |
1CUBRIC, Cardiff University, Cardiff, United Kingdom, 2Neuroscience and Mental Health Research Institute, Cardiff University, 3Cardiac Services, Cardiff and Vale University Health Board, Cardiff, United Kingdom, 4School of Medicine, Cardiff University, 5Centre for Trials Research, Cardiff University, Cardiff, United Kingdom, 6School of Physics and Astronomy, Cardiff University |
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Exercise is potentially therapeutic via vascular adaptations (angiogenesis, improved cerebral perfusion and metabolism) however the underlying dynamics are not fully understood. In Huntington´s disease (HD), where the therapeutic potential of exercise is being explored, cerebral vasculature alterations have been reported. Here we used arterial spin labelling to examine the acute effect of aerobic exercise on the cerebrovasculature in HD patients. We show that genetic disease load is related to both baseline cerebral blood flow (CBF) and the exercise-induced change in CBF. |
| 2502 | Lessons for MRI recruitment in movement disorder: Clinical presentation is not related to motion artefacts in arterial spin labelling MRI | |
1CUBRIC, Cardiff University, Cardiff, United Kingdom, 2Neuroscience and Mental Health Research Institute, Cardiff University, 3School of Medicine, Cardiff University, 4School of Physics and Astronomy, Cardiff University |
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Motion artefacts pose significant problems for the acquisition and analysis of MRI data. In movement disorders, severe motion-related artefacts can result in data being discarded as non-usable. It is not known to what degree clinical movement symptoms can predict in-scanner motion artefacts, and thus, whether researchers can target recruitment for MRI studies based on clinical presentation. Here we investigate whether movement severity in Huntington’s disease, a neurodegenerative movement disorder, can predict in-scanner motion artefacts in arterial spin labelling data. We find that motion magnitude and variability is not more pronounced in Huntington’s disease and not related to symptom severity. |
| 2503 | Cortical Recruitment of Motor Imagery in Timed Up and Go Task | |
1Department of Neuology, University of California, San Francisco, San Fransisco, CA, United States, 2Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, 3Department of Radiology and Biomedical Imaging, University of California, San Francisco |
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A paradigm was developed to evaluate neural pathophysiology of gait and turning in individuals with Parkinson’s disease (PD) using fMRI. BOLD signal change of imagined walking and turning was compared to resting state activation in PD patients and controls. Subjects performed physical examinations including the Timed Up and Go (TUG) task, ten-meter walk and a timed 360-degree turn to assess motor performance. Brain activity was compared between groups and to motor performance. This study concluded that a neural correlate of the TUG task exists in BOLD signal change in the premotor and primary motor area when imagining-turning compared to imagining-walking. |
| 2504 | Benefits of high-resolution QSM acquisition protocol for DBS surgery planning | |
1Meing School of Biomedical Engineering, Cornell University, Ithaca, NY, United States, 2Radiology, Weill Cornell Medical College, New York, NY, United States, 3Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, People's Republic of China, 4Weill Cornell Medical College, New York, NY, United States, 5Department of Neurosurgery, Mount Sinai Health System, New York, NY, United States |
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Deep brain stimulation is a surgical procedure routinely used in the treatment of advanced stages of Parkinson disease. DBS involves implanting of stimulating electrodes inside the patient’s brain, with STN most commonly being the target brain structure. Treatment efficiency and absence of negative side effects is strongly dependent on precision of electrode placement; therefore, high requirements are imposed on preoperative patient imaging for proper identification of anatomy of interest. Histochemical studies suggest that iron (one of the major contrast contributors in QSM) is densely and heterogeneously distributed in STN. Furthermore, it is hypothesized that distribution of iron might be related to functional subdivisions in STN. Thus, DBS surgery planning might benefit from more precise calculation of susceptibility distribution, which would allow observe and characterize gradients in iron concentration in in vivo patient data potentially leading to minimization of non-motor side effects. Accordingly, we develop a high resolution QSM protocol for DBS presurgical MRI protocol. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2505 | Improvement in Visualization of Brachial Plexus by 3D TSE MR Neurography Using Combination of STIR with SPIR at 3.0T | |
1Department of Radiology, Kumamoto Saishunso National Hospital, Kumamoto, Japan, 2Department of Medical Imaging, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan |
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Magnetic resonance neurography (MRN) of the brachial plexus using a 3D turbo spin echo (TSE) sequence with short-term inversion recovery (STIR) reduces the effect of fat suppression at 3.0 T. In addition, the signal intensity of the brachial plexus is influenced by changing the effective echo time (TEeff). Therefore, we optimized the fat suppression technique and TEeff so that the 3D TSE sequence, using a combination of STIR with SPIR and an optimal TEeff (from170 ms to 293 ms), achieved better visualization of the brachial plexus without residual fat. |
| 2506 | Motion-Free MR Imaging of Brachial Plexus using the PROPELLER technique combined with Low-Refocus Flip Angle FSE | |
1Chiba Children's Hospital, Chiba, Japan, 2Tokyo Metropolitan University, Tokyo, Japan, 3Orthopaedic Surgery, Chiba Children's Hospital, Chiba, Japan, 4Eastern Chiba Medical Center, Chiba, Japan, 5Chiba Cancer Center, Chiba, Japan |
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The STIR Low-RFA PROPELLER method is a combination of STIR (Short-TI Inversion Recovery) suppressing fat signal homogenously and low refocus flip angle (Low-RFA) PROPELLER for flow signal reduction. Furthermore, the PROPELLER is able to reduce ghost generated by flow and motion, and to maintain high resolution by averaging of k-space. Consequently, the STIR Low-RFA PROPELLER method will be expected to produce clear brachial plexus imaging which is not affected by motion. In this study, we demonstrate that this new scheme (STIR Low-RFA PROPELLER) is superior to the conventional method (T2 weighted IDEAL) in the depiction of brachial plexus. |
| 2507 | Perfusion of Spinal Cord in postoperative patient with Cervical Spondylotic Myelopathy using MR DSC technique | |
1CBIR, School of Medicine, Tsinghua University, Beijing, People's Republic of China, 2Jishuitan hospital, Beijing, People's Republic of China |
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Cervical Spondylotic Myelopathy (CSM) is a major cause of spinal cord dysfunction. However, the relationship between the degree of stenosis, tissue degeneration and sensorimotor dysfunction have not been well understood.In this study, 3 healthy volunteers and 17 CSM patients with different postoperative recovery degree were involved. We investigate the perfusion of spinal cord using MR DSC technique. The results showed a significant correlation between CBV and the postoperative severity of symptom (Japanese Orthopaedic Association score), which indicate that MR DSC perfusion of spinal cord could be an imaging biomarker to evaluate and understand CSM. |
| 2508 | An Optimal Design for 32 Channel Head-Neck Coil | |
1Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen City, People's Republic of China, 2Department of Radiology and Biomedical Imaging, University of California San Francisco, CA, United States, 3UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, United States |
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In this study, we build an optimized 32 channel head-neck coil array to improve the weak SNR of area behind cervical spine from the previous designed neck-coil array. Two of the original eight neck coils is place to the area near scruff with a new structure. Comparing the optimized 32-channel head neck coil with the previous: imaging test has improved 63% higher than the previous coil array. For g-factor measurement, optimized neck coil array is the same as the previous one. The results indicate that the optimized coil array is better for neck imaging. |
| 2509 | Toward Clinical Translation of Quantitative Spinal Cord MRI: Serial Monitoring to Identify Disease Progression in Patients with Degenerative Cervical Myelopathy | |
1Neurosurgery, University of Toronto, Toronto, ON, Canada, 2Electrical Engineering, École Polytechnique de Montréal, 3Neurosurgery, University of Calgary, Calgary, AB, Canada, 4Medicine, University College Cork, Cork, Ireland, 5Medical Imaging, University of Toronto, Toronto, ON, Canada |
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Degenerative cervical myelopathy (DCM) is a common cause of disability, but mild patients are often managed non-operatively and monitored for deterioration. Popular clinical assessment tools are insensitive to detect subtle disease progression. In this study, we employ multi-parametric spinal cord MRI to monitor 15 DCM patients for progression over a 1-year period, in addition to a comprehensive battery of clinical assessments. The MRI results detected progressive tissue injury in 6/7 patients with definite clinical progression and 5 additional patients (4 of which had borderline clinical progression). These MRI assessments are now being incorporated into clinical practice to inform surgical decision-making. |
| 2510 | Reproducible fast T1 mapping of the human cervical spinal cord in vivo | |
1UCL Institute of Neurology, Queen Square MS Centre, UCL, London, United Kingdom, 2Philips Healthcare, Guilford, United Kingdom, 3Translational Imaging Group, Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, UCL, London, United Kingdom, 4Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy, 5Brain MRI 3T Mondino Research 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, quantitative T1 mapping in the human spinal cord (SC) has been limited to date, mainly due to its small size and sensitivity to artefacts. Here we assess the reproducibility of a time efficient (<5min) SC protocol for Inversion Recovery T1 mapping, which is considered the gold-standard method for T1 estimation. Scan-rescan experiments were performed in a cohort of 4 healthy subjects. High reproducibility (whole cord intraclass correlation=0.94) of T1 estimates was found, with whole cord intra-subject coefficient-of-variation<15% for all subjects. |
| 2511 | Optimization of Quantitative Magnetization Transfer Imaging for Accurate PSR Estimation in the Spinal Cord | |
1Department of Electrical 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 Medical Center, Nashville, TN, United States |
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Quantitative magnetization transfer (qMT) sampling schemes typically attempt uniform sampling of the MT z-spectrum but this may not be optimal for PSR estimation of the human spinal cord in vivo. We utilize Monté Carlo simulations of fitting synthetic qMT data to produce an optimal sampling scheme of the MT z-spectrum. This sampling scheme is evaluated in a healthy control and compared to current best practices where we see superior PSR estimation with our optimized sampling scheme. |
| 2512 | Application of Quantitative Microstructural MR Imaging with Atlas-based Analysis for Spinal Cord in Cervical Spondylotic Myelopathy. | |
1Radiology, Juntendo University School of Medicine, Tokyo, Japan, 2Health Science, Tokyo Metropolitan University, Tokyo, Japan, 3Radiology, The University of Tokyo Hospital, Tokyo, Japan, 4Siemens Japan K.K., Tokyo, Japan |
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We investigated MR fiber g-ratio, AVF and MVF in evaluation of microstructural changes in the spinal cord in patients with cervical spondylotic myelopathy, with using atlas-based analysis by spinal cord tool box. 19 patients and 5 normal controls were included. MT-sat and NODDI data were collected at 3T MRI. The right side of fasciculus cuneatus and bilateral lateral corticospinal tracts (LSCT) of AVF were significant lower (P=0.014, 0.017, 0.014, one-way ANOVA with Scheffé’s post-hoc test) and the left LSCT of MVF was significant higher (P=0.037) in the affected side spinal cord, compared with normal controls. |
| 2513 | Assessing changes within the lumbosacral spinal cord in neurological disease: preliminary results of a pilot in vivo MRI study | |
1UCL Institute of Neurology, Queen Square MS Centre, University College London, London, United Kingdom, 2UCL Institute of Neurology, Uro-Neurology, Department of Brain Repair & Rehabilitation, University College London, London, United Kingdom, 3Translational Imaging Group, Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 4UCL Institute of Neurology, Department of Molecular Neuroscience, University College London, London, United Kingdom |
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Magnetic resonance imaging (MRI)-derived tissue-specific measures of neuronal loss and demyelination were assessed at the lumbosacral level of the spinal cord (SC) in relation to neurological dysfunction. Acquisition of grey and white matter measures for the lumbosacral SC proved feasible, and were sensitive to detect tissue-specific changes in two neurological disorders commonly associated with lumbosacral cord involvement: Multiple system atrophy and Multiple sclerosis. This preliminary study demonstrates the utility of this cutting edge MRI acquisition method to detect pathological changes in the lumbosacral SC, and is a first step towards establishing new MRI biomarkers for these patient groups. |
| 2514 | High-Resolution MRI of Dental Ceramic Implants In Vivo | |
1Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Freiburg, Germany, 2Faculty of Medicine, University of Freiburg, Freiburg, Germany, 3Division of Oral and Maxillofacial Surgery, Medical Center - University of Freiburg, Freiburg, Germany, 4Department of Prosthodontics, Medical Center - University of Freiburg, Freiburg, Germany, 5Partner Site Freiburg, German Consortium for Cancer Research (DKTK), Heidelberg, Germany |
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The purpose of the study was to demonstrate the feasibility and evaluate the limitations of high-resolution MRI of ceramic implants in vivo. One healthy volunteer was subjected to high-resolution MRI before and after two zirconia dental implants were placed in the lower right jaw. Both implants were clearly depicted as signal voids, and no artifacts were observed using a turbo spin echo sequence. In conclusion, high-resolution in-vivo MRI of ceramic implants with an isotropic voxel size of (600 μm)3 is feasible within 5 minutes scan time. |
| 2515 | Mathematical Modeling for Evaluating Gustatory Stimulation of Parotid Gland by Proton Density MRI | |
1Master 's Program of Biomedical Informatics and Biomedical Engineering of Feng Chia University, Taichung, Taiwan, Taichung, Taiwan, 2Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan, Republic of China, 3Ph.D. program in Electrical and Communication Engineering in Feng Chia University, Taichung, Taiwan, Republic of China, 4Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan, Republic of China, 5Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, 6Ph.D. program of Technology Management, Chung Hua University, Hsinchu, Taiwan, Republic of China, 7Department of Medicine, Taipei Medical University, Taipei, Taiwan, Republic of China, 8Department of Dentistry, National Defense Medical Center, Taipei, Taiwan, Republic of China, 9Department of Radiology, National Defense Medical Center, Taipei, Taiwan, Republic of China |
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The parotid gland function is evaluated by gustatory stimulation using scintigraphy in clinic. Due to the saliva secretion of parotid, it is supposed to measure the water component of parotid gland using PD MRI instead of scintigraphy. Normally the drop magnitude and recover rate of signal-time curve after gustatory stimulation was used to evaluate the function of parotid gland. For more physiology and quantitative parameters of characteristics of signal-time curve, we developed a mathematical model for drainage and refill of a toilet tank to quantify the parotid gland function in this study. |
| 2516 | Residual tumour detection in post-treatment granulation tissue by using multiple diffusion models in head and neck squamous cell carcinoma patients | |
1Hokkaido University Hospital, Sapporo, Japan |
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We assessed the utility of diffusion parameters obtained by multiple fitting models for the determination of the presence of the residual tumor after the curative chemoradiation in patients with head and neck squamous cell carcinoma (HNSCC). The result of the current study revealed the center of the Gaussian distribution of diffusion coefficient (Ds) in the statistical diffusion model and diffusion heterogeneity parameter in the stretched exponential model were respectively indicated as an independent predictor for the determination of the presence of residual tumor. This result will be useful information for the daily clinical follow-up in patients with HNSCC. |
| 2517 | Application of a flow-sensitive black blood (FSBB) T2* sequence to cranial nerve system contrast-enhanced imaging | |
1Division of radiology, kanazawa medical university, kahokugun, Japan, 2Department of radiology, kanazawa medical university, kahokugun, Japan |
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A flow-sensitive black blood (FSBB) sequence is usually used for 3D-T2*WI imaging. In an FSBB sequence, the vascular signal is suppressed by the effect of motion-probin- gradient (MPG) pulses. If this advantageous signal suppression is used, then 'contrast-enhanced volume black blood imaging' could be obtained. |
| 2518 | Atherosclerotic carotid plaque composition using in-vivo 3T, ex-vivo 7T MRI and histology | |
1Clinical Physics and Bioengineering, University of Glasgow, Glasgow, United Kingdom, 2NHS Greater Glasgow and Clyde, Glasgow, United Kingdom, 3GEMRIC, University of Glasgow, Glasgow, United Kingdom, 4Neuropathology, NHS Greater Glasgow and Clyde, Glasgow, United Kingdom, 5Vascular Surgery, NHS Greater Glasgow and Clyde, Glasgow, United Kingdom, 6Center for Stroke and Brain Imaging, University of Glasgow, Glasgow, United Kingdom, 7Institute of Neurological Siences, NHS Greater Glasgow and Clyde, Glasgow, United Kingdom |
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Atherosclerotic carotid plaque morphology and plaque composition may identify unstable or vulnerable plaque that defines higher risk. The aim of this study is to evaluate the ability to identify all major carotid plaque components in in-vivo 3T, ex-vivo 7T MRI and correlation with histology. |
| 2519 | Comparison of non-Gaussian diffusion parameters using different diffusion times in head and neck tumors | |
1Department of Diagnostic Imaging and Nuclear Medicine, Graduate Schoolof Medicine, Kyoto University, Kyoto, Japan, 2Hakubi Center for Advaned Research, Kyoto University, Kyoto, Japan, 3Department of Otolaryngology, Head and Neck Surgery., Graduate School of Medicine, Kyoto University, Kyoto, Japan |
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The association of diffusion parameters in patients with head and neck cancers was investigated using the different diffusion times. Although ADCo significantly decreased (p<0.05) and |
| 2520 | Assessment of image qualities of multi planar reformatted images depending on imaging planes of a variable refocus flip angle 3D FSE sequence (Cube) in cervical spine MRI | |
1Division of Radiology, Seirei Sakura Citizen Hospital, Sakura, Japan, 2Department of Radiology, Toho University Sakura Medical Center |
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The purpose of this study is to assess image qualities of MPR images depending on imaging planes of Cube to determine the optimal imaging plane in the cervical spine. The differences of FWHMs in frequency and phase encoding directions of the transverse, sagittal, coronal source images were compared and those encoding directions on the transverse, sagittal, coronal MPR images were compared. MRI of Volunteers image qualities were recorded by assessing sharpness of the vertebral body, spinal cord, and nerve roots on the images. To provide better image qualities in cervical spine MRI using Cube, transverse planes should be selected. |
| 2521 | Texture Analysis of MR Images in Pediatric Cervical Spinal Cord Injury | |
1Temple University, Philadelphia, PA, United States, 2Radiology, Thomas Jefferson Hospital University, Philadelphia, PA, United States, 3Occupational Therapy, Thomas Jefferson Hospital University, Philadelphia, PA, United States, 4Radiology, Temple University, Philadelphia, PA, United States |
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In this study we have investigated on evaluating the ability of texture analysis of routine conventional pediatric spinal cord MRI to characterize the changes of diseased or injured spinal cord. |
| 2522 | Evaluation of cervical carotid plaque volume using 3D T1 black-blood MRI : Comparison of manual measurement and automated measurement by the software. | |
1Department of Radiology, Mie University Hospital, Mie, Japan, 2Department of Advanced Diagnostic Imaging, Mie University School of Medicine, Mie, Japan, 3Department of Electronic and Computer Engineering, Ritsumeikan University, Shiga, Japan, 4Department of Radiology, Mie University School of Medicine, Mie, Japan |
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Quantitative assessment of carotid plaque burden is required to monitor the effects of treatments for carotid atherosclerosis. Cervical carotid plaque volume in 13 patients with carotid artery stenosis was measured and evaluated using manual and automated software methods for 3D T1 black-blood MRI. Measurement reproducibility was better using the automated method than that using the manual method. The automated software developed for the measurement of carotid plaque volume was feasible and reliable and could significantly reduce the measurement time. This method appears to be of great value in clinical settings. |
| 2523 | First Application of 7T Structural, Vascular, and Diffusion Imaging to Trigeminal Neuralgia: Preliminary Results in Patients | |
1Radiology, Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Biomedical Engineering, City University of New York, New York, NY, United States, 3Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 4Neuroradiology, Mount Sinai Medical Center, New York, NY, United States, 5Neurosurgery and Otolaryngology, Mount Sinai Medical Center, New York, NY |
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Trigeminal neuralgia (TN) is a debilitating condition characterized by severe facial pain. The pathophysiology of TN is not well understood and conventional clinical imaging often fails to identify the anatomical source of pain. In this study, we perform high-resolution 7T structural, vascular and diffusion-weighted MRI to visualize the trigeminal nerve region in three TN patients and three controls. We found that 7T-MRI provided improved visualization of nerve abnormalities compared to clinical scans. We also found greater nerve asymmetry in TN patients compared to controls. Multi-modal 7T-MRI could enhance our understanding of TN etiology and provide improved clinical outcomes for TN. |
| 2524 | Spinal Cord MRI Water Diffusion Alterations are Linked to Early Axonal Degeneration in the YFP, G93A-SOD1 mice. | |
1Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, United States, 2Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States, 3Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, United States |
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Amyotrophic lateral Sclerosis (ALS) is characterized by progressive degeneration of spinal cord motor neurons. To address the role of axonal pathology in ALS, we generated a YFP,G93A-SOD1 reporter mice. Our goal in this study is to evaluate if presymptomatic alterations in MRI water diffusion in the YFP,G93A-SOD1 mice are related to alterations in axonal connectivity by histological methods. Results showed presymptomatic changes in diffusion parameters are associated to specific structural changes in axonal population. The use of this new animal model will help us to understand the structural basis of changes in water diffusion in ALS. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2525 | Gradient and Spin Echo (GRASE) as an Alternative to Multi Echo Spin Echo (MESE) acquisition for Myelin Water Fraction Imaging | |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Klinik und Poliklinik für Neuroradiologische Diagnostik und Intervention, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany |
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Problem: The clinical utility of myelin water fraction (MWF) mapping based on multi-echo-spin-echo (MESE) T2-relaxometry is prohibitively slow (~90-120 minutes for acquisition matrix 128x128x50; TR 3s). MWF-values from T2-prep based approach and mcDESPOT (Multicomponent-driven-equilibrium-single-pulse-observation-of-T1-and-T2) matches poorly with MESE based quantification. Methods: We compare GRASE (Gradient-and-Spin-Echo) based MWF quantifications against those from MESE and compare our algorithm against current state of the art. 3D non-selective GRASE, MESE were optimized. Implemented post-processing method utilizes spatial correlations in 3D local neighborhoods to improve noise stability, while simultaneously accounting for stimulated echo contributions. Results & Conclusions: Results demonstrate good consistency between both sequences. |
| 2526 | Correlation between thalamic volume and cognitive impairment in patients with MS using a high-efficiency semi-manual segmentation approach | |
1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States, 2Psychology, University of Kansas, 3Neurology, University of Kansas Medical Center, Kansas City, KS, United States, 4Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, United States |
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Thalamic pathology has been linked to long-term accumulation of disability and cognitive impairment in MS. However, assessment of thalamic volume is highly challenging for automatic as well as manual segmentation techniques. The use of multiple image contrasts may improve segmentation quality. We investigated correlations of thalamic volume and cognitive performance in MS. We evaluated automatic segmentation and our new semi-manual segmentation using T1 and proton-density MRI. Results based on FreeSurfer segmentation failed to yield correlations of thalamic volume with cognitive performance in MS patients. Using semi-manual segmentation, significant correlations were found between cognitive impairment and regional thalamic atrophy in MS. |
| 2527 | Iron is a biomarker for differentiating multiple sclerosis lesions from ischemic demyelinating lesions | |
1Tongji hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, People's Republic of China, 2Neurology, Weill Cornell Medical College, NY, United States, 3Radiology, Weill Cornell Medical College, NY, United States, 4Department of Biomedical Engineering, Cornell University |
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Differentiation MS lesions from ischemic demyelinating lesions is important because of their totally different treatment strategies. Our results suggested that the increased susceptibility of demyelinating lesions, the presence of QSM-ring lesions and the central vein in the lesions helped to differentiate MS lesions from ischemic demyelinating lesions. Thus, QSM provided the underling iron-related pathogenesis of MS lesions, which enable to differentiate MS lesions from ischemic demyelinating lesions. |
| 2528 | Inhomogeneous Magnetization Transfer (ihMT) in normal-appearing tissue correlates with clinical EDSS score of MS patients. | |
1Aix-Marseille Univ, CNRS, CRMBM UMR 7339, Marseille, France, 2Radiology, Division of MR Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States, 3Aix Marseille Univ, APHM, Hôpital La Timone, Pôle de Neurosciences Cliniques, Service de Neurologie, Marseille, France |
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The present study was aimed at evaluating the potential of ihMT (inhomogeneous Magnetization transfer) contrast in characterizing the severity of MS disease, and investigating possible correlations between ihMT and the clinical disability score. |
| 2529 | A New Iterative GPU Algorithm to Segment MS Lesions in Multi-spectral MRI Datasets | |
1Biomedical Informatics, Arizona State University, Scottsdale, AZ, United States, 2Radiology, Mayo Clinic, AZ, United States, 3Neurology, Mayo Clinic, AZ, United States, 4Research, Mayo Clinic, AZ, United States |
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This paper presents a new method to segment MS lesions in multi-spectral MRI exams. Our approach leverages the speed of a GPU level set algorithm and a new data term to perform multiple segmentations of brain white matter in each exam. Differences between these segmentations allow us to estimate the distribution of MS lesions. We evaluated our method on BrainWeb and MS Lesion Segmentation Challenge 2008 data. It achieved results comparable to, or better than, two top performing algorithms. The average time required by our algorithm for Challenge08 data was 20.8 seconds. |
| 2530 | Thalamic involvement in neuromyelitis optica spectrum disorder: multicomponent relaxometry parameters and relationship with cognition | |
1Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom, 2Neurology, University of British Columbia, Vancouver, BC, Canada, 3Radiology, University of British Columbia, Vancouver, BC, Canada |
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Investigations into thalamus pathology, a known predictor of disease progression and cognitive impairment in multiple sclerosis, have yielded inconsistent results in neuromyelitis optica spectrum disorder. We found significant thalamic atrophy, but normal multicomponent relaxometry parameters in patients compared to healthy controls, providing further evidence that despite volume loss, microstructural alterations are likely subtle. Associations between MRI metrics (thalamic volume and T1 relaxation time, linked with changes in water content) and performance on two measures of information processing speed support the hypothesis that damage to the thalamus may be involved in cognitive impairment in this population. |
| 2531 | The cytoarchitectonic anterior-posterior subdivision of BA4 reveals different resting state networks suggestive of maladaptive mechanisms in MS | |
1UCL Institute of Neurology, Queen Square MS Centre, University College London, London, United Kingdom, 2Department of Diagnostic Radiology, Faculty of Applied Medical Science, KAU, Jeddah, Saudi Arabia, 3Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, University of Genoa, Genoa, Italy, 4Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy, 5Brain Connectivity Centre, C. Mondino National Neurological Institute, Pavia, Italy, 6Wellcome Centre for Imaging Neuroscience, University College London, London, United Kingdom, 7Brain MRI 3T Mondino Research Center, C. Mondino National Neurological Institute, Pavia, Italy |
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This study investigates whether it is possible to characterise different resting state fMRI (rsfMRI) networks connected to the cytoarchitectonic subdivisions of Brodmann area 4 (BA4) and how these networks behave in the presence of multiple sclerosis (MS). We showed that each sub-region identifies different rsfMRI networks, with the BA4p network including more associative and higher order functional areas whereas the BA4a network includes more force-related and motor areas. In MS, functional connectivity to the right hemisphere was lost and was positively correlated with the 9-HPT, suggesting a maladaptive mechanism rather than a compensatory mechanism. |
| 2532 | Assessment of neuronal dysfunction in benign multiple sclerosis: a sodium MRI study | |
1Aix-Marseille Univ, CNRS, CRMBM, Marseille, France, 2Aix-Marseille Univ, APHM, Hopital de la Timone, CEMEREM, Marseille, France, 3Aix Marseille Univ, APHM, Hôpital de la Timone, Pôle de Neurosciences Cliniques, Service de Neurologie, Marseille, France |
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Assessment of neuro-degenerative process in multiple sclerosis using sodium MRI. A study in a population of 135 subjects at different disability and disease duration |
| 2533 | Sensitivity to pathological normal appearing white matter damage in multiples sclerosis – a comparison of DTI and DKI | |
1Technische Universität München, Munich, Germany, 2GE Global Research, Munich, Germany, 3Max Planck Institute of Psychiatry, Munich, Germany, 4GE Heathcare, Paris, France, 5GE Global Research, Munich |
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A systematic comparison of diffusion tensor imaging (DTI) and diffusional kurtosis imaging (DKI) regarding the sensitivity to non-pathological white matter in multiple sclerosis is presented. We found first indications for a higher sensitivity of DKI compared with DTI in the normal appearing white matter compartment. |
| 2534 | Distinct patterns of network-wise functional connectivity impairment discriminate Relapsing-Remitting Multiple Sclerosis with different disease duration | |
1Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, Italy, 2Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, Italy, 3New Zealand Brain Research Institute, Christchurch, New Zealand, 4University of Otago, Christchurch, New Zealand, 5University of Canterbury, Christchurch, New Zealand, 6Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy, 7Queen Square MS Centre Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom, 8Department of Neurology, Christchurch Hospital, Christchurch, New Zealand, 9Brain MRI 3T Research Center, C. Mondino National Neurological Institute, Pavia, Italy |
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In this work we examined functional connectivity (FC) changes within and between the resting state networks (RSNs) caused by Relapsing Remitting Multiple Sclerosis (RRMS) in two cohorts showing mild disability but different disease duration. Our results demonstrate widespread functional alterations in both short and long duration RRMS groups (MS1 and MS2). The MS1 group showed more severe FC alterations compared to the MS2 group. Overall, these results suggest that there may be pathophysiological differences in RRMS groups with different disease durations. Longitudinal studies would be needed to investigate whether FC findings are able to predict the future course. |
| 2535 | Automated evaluation of deep gray matter neuronal damage in multiple sclerosis patients | |
1Advanced Clinical Imaging Technology, Siemens Healthcare HC CEMEA SUI DI PI, Lausanne, Switzerland, 2Department of Radiology, CHUV, Lausanne, Switzerland, 3LTS5, EPFL, Lausanne, Switzerland, 4Siemens Healthcare S.A.S., Saint-Denis, France, 5Department of Neurology, University Hospital Henri Mondor, Créteil, Switzerland, 6Department of Neuroradiology, University Hospital Henri Mondor, Créteil, France |
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We investigate the potential of a technique to automatize quantification of neuronal damage from T1-weighted MR scans in multiple sclerosis patients. T1 hypointense component measures in the deep nuclei are derived from 40 MPRAGE scans (21 relapsing-remitting MS and 19 age-matched controls) through combined brain tissue classification and atlas-based segmentation algorithms. Our analysis shows that these automated measures are significantly lower in the thalamus and putamen of MS patients, which is in line with previously reported loss of structure in these regions. |
| 2536 | Changes in White Matter Integrity in MS under Fingolimod Treatment for Two Years Revealed by HARDI | |
1Radiology, Cleveland Clinic, Cleveland, OH, United States, 2Neurology, Cleveland Clinic, Cleveland, OH, United States |
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In a 2 year longitudinal fingolimod study, we investigated the evolution of white matter integrity in the brain of relapsing-remitting multiple sclerosis (RRMS) patients under fingolimod treatment. Based on dMRI metrics from HARDI scans and statistical analysis, we found that MS patients experience a continued decline in white matter integrity during the first year of treatment with fingolimod with stabilization during the second year. Without a control group, it is unclear if these trends reflect on the impact of a treatment on disease progression. |
| 2537 | Gaining insights into Multiple Sclerosis Lesion Characteristics from Brain Tissue Microstructure Information: A multi-compartment T2 relaxometry Approach | |
1VisAGeS, IRISA U746, Universite de Rennes-1, Rennes, France, 2VisAGeS Inserm U746, IRISA, Inria, Rennes, France, 3Boston Children’s Hospital, Boston, MA, United States, 4VisAGeS, INRIA/IRISA, Inserm U746, CNRS, Rennes, France |
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Clinical trends and Pathogenetic ways of onset and progression of Multiple Sclerosis (MS) in patients suggest that MS is a highly heterogeneous disease. MS is predominantly a White Matter (WM) disease, which is mainly composed of myelinated axons and neuroglia type cells. Demyelination and axonal loss characterize the condition of MS in a patient. However, they follow varying trends in patients. In this work, we propose a method in which T2 relaxometry data is used to obtain a quantitative brain tissue microstructure information. This information is then studied to check its corroborations with pathogenetic understanding of MS in literature. |
| 2538 | Investigation on Optic Neuritis with DTI and Understanding Its Underlying Pathology using Monte Carlo Simulation. | |
1Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States, 2Department of Neurology, University of Utah, 3Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States |
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To understand the underlying physical and pathological meaning of optic-nerve in optic-neuritis(ON), diffusion-tensor imaging (DTI) and the corresponding Monte-Carlo Simulation (MCS) were conducted. DTI studies of four healthy subjects and seven ON patients with MS were performed and analyzed by home-built software. The measured DTI indices allowed us to monitor pathological changes such as inflammation in ON or demyelination. To investigate the clinical meanings of changes in diffusion parameters, MCS of water diffusion in optic nerve was performed. |
| 2539 | Z-Score Approach to the Detection of Cortical Lesions in Multiple Sclerosis | |
1Department of Radiology, University of Vermont, Burlington, VT, United States, 2Department of Neurological Sciences, University of Vermont, Burlington, VT, United States |
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A new technique combining surface-based cortical myelin maps with Z-score methodology is developed to identify foci of cortical demyelination in patients with multiple sclerosis. The technique is found to discriminate (p=0.002) patients with MS (n=19) from patients with migraine (n=10), who often present with similar symptoms and white matter imaging findings. Regions of unusually low myelin content may correspond to lesions visible on the source T1-weighted and FLAIR images, but in other cases may be occult on either individual scan. The technique is clinically applicable, requiring only 3D T1 and FLAIR acquisitions that are already the standard of care in clinical neuroimaging. |
| 2540 | Optimization of Neurite Orientation Density and Dispersion Imaging (NODDI) for In Situ Imaging | |
1Imaging Institute, The Cleveland Clinic, Cleveland, OH, United States, 2Mellen Center for Multiple Sclerosis, The Cleveland Clinic, Cleveland, OH, United States |
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In situ imaging is a valuable context for validation of imaging measures against histology. This contribution describes optimization of diffusion MRI for NODDI in in situ imaging of a multiple sclerosis patient. The results are expected to facilitate validation of advanced diffusion MRI and other tissue microstructure meausrements. |
| 2541 | Reduced fibre density in the visual pathways of multiple sclerosis patients with optic neuritis | |
1Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Australia, 2The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia, 3Department of Radiology, Royal Melbourne Hospital, Melbourne, Australia, 4School of Psychological Sciences and Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Melbourne, Australia, 5Department of Neurology, Royal Melbourne Hospital, Melbourne, Australia, 6The Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia, 7Department of Medicine, University of Melbourne, Melbourne, Australia |
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Axonal degeneration is a key pathological driver of disability in multiple sclerosis (MS). Treatments aiming to reduce or reverse axonal degeneration in MS require sensitive and specific markers. Here we explore putative fibre-specific markers of axonal degeneration based on diffusion-weighted MRI metrics – fibre density and fibre bundle cross-section. MS patients with optic neuritis were compared to control subjects. We identified significant reductions to both fibre density and cross-section in the visual pathways of patients. These results indicate the pathological specificity of fibre density and cross-section measures in MS. |
| 2542 | Ultra High Field Regional Quantitative Susceptibility Mapping in Patients with Relapsing-Remitting Multiple Sclerosis: A Pilot Study | |
1Melbourne Brain Centre Imaging Unit, Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia, 2MS Research Group, Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia |
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Multiple sclerosis (MS) is typically characterised by hyperintense T2 white matter lesions. However, the quantity and location of these may not correlate to a patient’s functional state or impending disease progression. Quantitative susceptibility mapping (QSM) is an emerging biomarker associated with tissue iron concentration and regions of demyelination in white matter. This pilot study examined both clinical and MRI parameter relationships to the QSM value over a number of brain regions in patients with mild (EDSS =or<2) relapsing and remitting MS. |
| 2543 | Pushing the limits of synthetic MRI in the evaluation of patients with Multiple Sclerosis: how much can the acquisition time be reduced? | |
1DASA, Rio de Janeiro, Brazil, 2Universidade Federal Fluminense, Rio de Janeiro, Brazil, 3GE Healthcare Brazil, Rio de Janeiro, Brazil, 4GE Healthcare Brazil, 5UFRJ, Rio de Janeiro, Brazil, 6DASA, Sao Paulo, Brazil |
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In synthetic MRI, the recently developed multi delay multi–echo fast spin echo sequence (MDME) with posterior mathematical fitting provide multiple image contrasts in a single sequence acquisition and lead to potential acquisition time reductions. In this study, both, a synthetic MRI and conventional post contrast acquisition protocol for the evaluation of patients with Multiple Sclerosis were compared. Significant acquisition time reduction were achieved with synthetic MRI without neglecting lesion count capabilities |
| 2544 | Cortical Surface Magnetization Transfer Ratio Decreases in Multiple Sclerosis are Age and Region Dependent | |
1McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada |
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Cortical pathology may be a substrate of worsening clinical symptoms in MS patients. However, the rate at which cortical pathology develops and the brain locations affected are not well known. The goal of this study was to evaluate longitudinal, age-related reductions in cortical surface magnetization transfer ratio (csMTR) of MS patients. Such reductions may be sensitive to sub-pial demyelination occurring over time. |
| 2545 | The cerebello-thalamic tract as a neural correlate for tremor in MS | |
1Melbourne Brain Centre, University of Melbourne, Melbourne, Australia, 2The Royal Melbourne Hospital, Melbourne, Australia, 3Radiology, Royal Melbourne Hospital, Melbourne, Australia |
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This study aims to determine the correlation between clinical tremor severity in Multiple Sclerosis (MS) and the cerebello-thalamic pathway. We found a decrease in volume of the ipsilateral Superior Cerebellar Peduncle and contralateral Thalamus. These regions of volume loss correlate with predicted neuro-anatomy indicating that the cerebello-thalamic pathway is a neural correlate of tremor severity in MS. This finding aids to a better understanding of pathogenesis and development of treatments for tremor in MS. |
| 2546 | New Enhancing and Chronic Multiple Sclerosis Lesions measured on Quantitative Susceptibility Mapping and Diffusion-Weighted Imaging | |
1Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, People's Republic of China, 2Department of Radiology, Weill Cornell Medical College, New York, NY, United States, 3Biomedical Engineering, Cornell University, Ithaca, NY, United States |
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QSM and DWI are sensitive to changes in MS lesions at various ages. We found chronic MS lesions had higher relative susceptibilities and lower relative ADC values as compared to new enhanced lesions. Combining QSM and ADC measurements could differentiate each two subtypes in four subtypes of lesions (nodular/shell enhanced lesions, rim+/- lesions). The pattern of QSM and ADC findings suggests that shell enhanced lesions have more demyelination than nodular enhanced lesions and rim- lesions. Combining QSM and ADC measurements might be a better way to differentiate MS lesions at various ages and provide more information of micro-changes of lesion. |
| 2547 | STRUCTURAL AND FUNCTIONAL MRI PREDICTORS OF DISABILITY AND COGNITIVE IMPAIRMENT ACCRUAL IN PATIENTS WITH MULTIPLE SCLEROSIS | |
1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy, 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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Aim of this study was to identify the MRI predictors of medium-term disability and cognitive impairment accrual in patients with the main clinical phenotypes of multiple sclerosis (MS). Results indicated that clinical disability and cognitive impairment at follow-up were predicted by measures of structural and microstructural damage, as well as by resting state functional connectivity measures. Preserved white matter integrity predicted clinical improvement. Grey matter involvement played a critical role in MS-related clinical worsening and evolution to a more severe disease phenotype. |
| 2548 | Noise reduction with TGV, Gaussian and Wiener filtering methods in FLAIR² images | |
1Department of Radiologic Technology, Carinthia University of Applied Sciences, Klagenfurt, Austria, 2UBC MRI Research Centre, University of British Columbia, Vancouver, Canada, 3Institute for Mathematics and Scientific Computing, University of Graz, Graz, Austria, 4Department of Radiology, Medical University of Graz, Graz, Austria, 5Institute for Applied Research on Ageing, Carinthia University of Applied Sciences, Klagenfurt, Austria |
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The reduction of noise is of high value for FLAIR² images because the multiplication of FLAIR and T2 images will always result in an image with a reduced Signal-to-noise-ratio. Here different filter methods, like Gaussian, Wiener and Total Generalized Variation were used to demonstrate noise reduction. The drawback of noise reduction is a blurring effect of anatomical structures. In this study we demonstrate that TGV filtering has certain advantages compared to Wiener and Gaussian techniques in research and clinical applications. |
| 2549 | Rapid, high-resolution imaging of the central veins in multiple sclerosis at 1.5T, 3T, and 7T | |
1Translational Neuroradiology Section, NINDS, National Institutes of Health, Bethesda, MD, United States, 2Siemens Medical Solutions, HC NAM USA DI MR COLLAB, Bethesda, MD, United States, 3InatiAnalytics, Potomac, MD, United States, 4Siemens Medical Solutions, HC NAM USA DI MR COLLAB NE, Boston, MA, United States |
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The central vein sign (CVS) detected by magnetic resonance imaging (MRI) may aid with the diagnosis of multiple sclerosis (MS). The ability to detect central veins in the brain at any magnetic field strengths would open the pathway for future large-scale research studies, and potentially routine clinical use, of the CVS for MS diagnosis. In this study, a fast high-isotropic-resolution, whole-brain T2*-weighted segmented echo-planar-imaging acquisition was implemented at 1.5T, 3T and 7T. Central veins inside multiple sclerosis lesions were detected at all three different field strengths. |
| 2550 | Functional MRI detects a novel cerebral venous haemodynamic signal that is disrupted in early multiple sclerosis | |
1Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia |
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Here we report a novel haemodynamic signal using BOLD-weighted fMRI that is restricted to the internal cerebral veins and identifiable in all subjects assessed to date. This signal is oscillatory with peak power at 0.054 Hz. In early MS patients, venous power was diminished compared to controls. Venous power was inversely correlated with T2 lesion volume but not brain atrophy. These results indicate that neuroinflammation is associated with altered venous haemodynamics that could be attributable to venous structural damage previously reported in MS. This novel venous signal should also be investigated more broadly in cerebrovascular disease. |
| 2551 | Baseline DTI discriminates and predicts MS from ADEM | |
1Washington University in St. Louis, School of Medicine, St. Louis, MO, United States, 2St. Louis University, School of Medicine, St. Louis, MO, United States |
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MS is a progressive disorder in which demyelination, axonal degeneration, and inflammation contribute to disease pathogenesis. ADEM is classically an acute, monophasic demyelinating disease in which axonal damage is present but minimal. About 20 percent of ADEM cases can have relapses and are diagnosed with MS later, posing a diagnostic dilemma at initial presentation. In this study, we investigate the role of directional diffusivity DTI as a MR biomarker to differentiate and predict Acute Disseminated Encephalomyelitis (ADEM) from Multiple Sclerosis (MS) in pediatric patients. |
| 2552 | The Role of Node Strength in Investigating Pathology | |
1Institute of Neurology, University College London, London, United Kingdom, 2Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, 3Translational Imaging Group, Centre for Medical Image Computing, Department of Medical Physics and Biomedical Imaging, University College London, London, United Kingdom, 4Medical Statistics Department, London School of Hygiene and Tropical Medicine, London, United Kingdom, 5National Hospital of Neurology and Neurosurgery, London, United Kingdom, 6Institute of Child Health, University College London, London, 7Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy, 8Brain MRI 3T Mondino Research Center, C. Mondino National Neurological Institute, Pavia, Italy |
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Graph theoretical network properties, while successful in exploring topological features of entire brain networks, have limited sensitivity to localized disease effects. This work explores the role of node strength as an objective way to characterize disease. Differences in the default mode network (DMN) between a cohort of relapsing-remitting multiple sclerosis (RRMS) patients and healthy controls (HC) have been explored using standard graph metrics (e.g. efficiency) and node strength. No differences in graph metrics were observed between the groups; however several key regions of the DMN had a significantly reduced strength in RRMS than HC (5% significance level). |
| 2553 | Real Time MRI-guided convection-enhanced delivery in porcine brain to model multiple sclerosis by focal demyelination | |
1Department of Neurology and Neurosurgery, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland, 2Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, John Hopkins University, Baltimore, MD, United States, 3Russell H. Morgan Department of Radiology and Radiological Science, John Hopkins University, Baltimore, MD, United States, 4NeuroRepair Department, Mossakowski Medical Research Center, Polish Academy of Sciences, Warsaw, Poland, 5Department of Surgery and Roentgenology with the Clinic, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland, 6Department of Pathophysiology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland |
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Modeling of multiple sclerosis is typically performed in rodents; however, due to several limitations large animal models are needed to improve clinical relevance. In this study we utilized MRI-guided convection enhanced delivery of gliotoxins (ethidium bromide and lysolecithin) to induce focal demyelination within corona radiata in pigs. |
| 2554 | Quantitative Assessment of Limbic System Damage in Multiple Sclerosis | |
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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The limbic system plays an important role in the emotion- and memory-related brain functions. In this study, we measured R2* and the volumes of the key elements of the limbic system and used them to detect abnormalities in the limbic system in multiple sclerosis (MS). The results showed significant differences between Secondary Progressive MS (SPMS) and healthy group. R2* of amygdala, thalamus, insula, lateral orbitofrontal and isthmus cingulate significantly correlate with clinical cognitive tests in female SPMS. Our results also showed that R2*-defined tissue alterations in the hippocampus and entorhinal cortex could identify depression behavior in MS patients. |
| 2555 | Conversion of Brain Tissue volumes by MR Images form 1.5 to 3.0 Tesla scanners for Multiple Sclerosis patients | |
1University of Sao Paulo, Ribeirao Preto, Brazil |
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Brain tissue volume estimation based on MRI is crucial to several diseases such as multiple sclerosis (MS). The Images from different scanners with dissimilar magnetic fields have disparities in resolution, Signal to Noise Ratio, contrast, among others. In order to convert volume estimations from different scanners, we suggest and evaluated two methods. The dataset to validate the methods was selected from 14 years follow up study of 72 MS patients with 1.5 and 3.0 Tesla acquisitions. The quantitative study of tissue volume progress is possible using these two methods. |
| 2556 | T1 Black Hole in Multiple Sclerosis: a reassessment of the specificity at 7T | |
1Vanderbilt University, Nashville, TN, United States, 2Medical University Vienna |
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7T imaging and the commensurate T1-lenghtening have the potential to increase lesion sensitivity at the expense of their specificity in patients with multiple sclerosis. In our work we demonstrate that (1) T1-hypontense lesions detected on T1-w MPRAGE reflect both remyelinated and chronic demyelinated lesions as measured by histology and that (2) associations between black hole lesion load and measures of physical and cognitive disability are weak. At 7T, the increased sensitivity to lesion penalizes the T1-w MPRAGE specificity to areas with higher water content and tissue destruction seen at lower field strength. |
| 2557
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Histological Validation of Diffusion Basis Spectrum Imaging Using Autopsied Multiple Sclerosis Brain Specimens | |
1Department of Radiology, Washington University, St. Louis, Saint Louis, MO, United States, 2Department of Radiology, Washington University, St. Louis, 3Department of Neurology, Washington University, St. Louis, MO, United States, 4Advanced Imaging Research Center, Oregon Health & Science University, OR, United States, 5Radiological Health Sciences, School of Health Sciences, Purdue University, West Lafayette, IN, United States, 6Department of Radiology, Washington University, St. Louis, MO, United States |
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In this study, we demonstrate diffusion basis spectrum imaging (DBSI) is able to detect, differentiate and quantify different coexisting pathologies, particularly axonal loss and demyelination within autopsied multiple sclerosis human brain specimens. We correlated the DBSI derived maps with quantitative histology maps generated by means of color based segmentation. DBSI-derived fiber fraction was seen to correlate with Bielschowsky’s silver stain for axonal integrity, and the DBSI-derived radial diffusivity negatively correlated with Luxol Fast Blue-Periodic Acid-Schiff (LFB-PAS) stain for myelin integrity. |
| 2558 | mcDESPOT-derived tissue parameters in the brainstem and corpus callosum of MS and NMOSD patients with cervical cord lesions | |
1Department of Medicine, University of British Columbia, Vancouver, BC, Canada, 2Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom, 3Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, 4Department of Radiology, University of British Columbia, Vancouver, BC, Canada |
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Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are demyelinating central nervous system disorders that may present with some overlapping clinical symptoms but differ pathophysiologically. We used tissue-specific quantitative measures, produced by mcDESPOT, to characterize tissue pathology in MS and NMOSD groups compared to healthy controls. We observed decreased myelin water fraction, increased T2 of intra/extracellular water, increased cerebrospinal volume fraction, and increased myelin water residence time in the brainstem and corpus callosum of MS and NMOSD subjects, compared to controls. These sensitive advanced MRI measures could provide an improved understanding of MS and NMOSD pathogenesis. |
| 2559 | High-resolution spinal DTI imaging using RESOLVE sequence in multiple sclerosis and clinical isolated syndrome | |
1Department of Radiology, Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin, People's Republic of China, 2MR Collaborations NE Asia, Siemens Healthcare, Beijing, People's Republic of China |
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This study reports the preliminary application of high-resolution diffusion tensor imaging (DTI) using readout segmentation of long variable echo trains (RESOLVE) sequence for spinal cord imaging in patients with demyelinating conditions. Patients with clinical isolated syndrome (CIS) and multiple sclerosis (MS) were recruited in order to investigate image evidences in early stages and the progression of the disease. The results of DTI analyses demonstrate that MS is characterized by diffuse axonal compensation in the spinal cord. |
| 2560 | Measures of tissue coherency in T2-weighted MRI for myelin and axonal pathology: A MRI-histology correlative study in multiple sclerosis | |
1Biomedical Engineering Program, University of Calgary, Calgary, AB, Canada, 2Departments of Neurology and Clinical Neurosciences, University of Calgary, AB, Canada |
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Measurement of tissue coherency has been largely relying on advanced MRI. Here we presented a coherency-assessing method based on standard T2-weighted MRI. Postmortem brain samples from multiple sclerosis (MS) patients were used to validate our method. It was based on Fourier transform power spectrum, from which dominant tissue-aligning directions and angular entropy were calculated. Tissue coherency in histology was quantified using structure tensor analysis. We found that both MRI and histology coherency differentiated MS lesions from NAWM, and that MRI coherency correlated significantly with histological results. These findings suggest the potential of T2-weighted MRI in characterizing advanced tissue pathology |
| 2561 | Ultra-High B Diffusion Imaging of Cervical Spinal Cord in Multiple Sclerosis | |
1Utah Center for Advanced Imaging Research, University of Utah, salt lake city, UT, United States, 2Department of Physics and Astronomy, University of Utah, salt lake city, UT, United States, 3Department of Radiology and Imaging Sciences, University of Utah, salt lake city, UT, United States, 4Department of Neurology, University of Utah |
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Diffusion tensor imaging (DTI) is considered as a biomarker to quantitatively evaluate the pathology in the cervical spinal cord (CSC) in MS patients. However, DTI parameters, including axial and radial diffusivities, and fractional anisotropy (FA), provides signal behavior of the water diffusion at a specific diffusion weighting. Using a ultra-high B DWI on a CSC specimen and Monte-Carlo Simulation indicate that we can learn much more insights about the CSC pathology by analyzing the signal-b curve at b > 4000 s/mm2. In this presentation, we will show unique signal behaviors of UHB-rDWI in acute and chronic legions in MS CSC. |
| 2562 | Tract Based Whole Brain White Matter Analysis using Diffusion Basis Spectrum Imaging in Multiple Sclerosis | |
1Radiology, Washington University in Saint Louis, Saint Louis, MO, United States, 2Neurology, Washington University in Saint Louis, Saint Louis, MO, United States |
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Axon injury and loss, demyelination, and inflammation are the primary pathologies in multiple sclerosis (MS). However, the roles that these individual pathological processes play in MS progression are still ill defined. To investigate whole brain white matter (WM) changes, diffusion tensor imaging (DTI) and diffusion basis spectrum imaging (DBSI) were analyzed on Tract Based Spatial Statistics (TBSS) skeleton template. Both whole brain voxel-based group analysis and regional correlation analysis at the corpus callosum supported that DBSI metrics were able to quantitatively assess the white matter alterations. DBSI could be useful for quantitatively monitoring MS patient treatment and assessing neuroprotective therapies. |
| Exhibition Hall | Wednesday 13:45 - 15:45 |
| 2563 | Chronic pain-related sexual dimorphism in gray matter density: A whole-brain voxel-based morphometric study on Osteoarthritis patients | |
1University of Nottingham, Arthritis Research UK Pain Centre, Nottingham NG7 2RD, England, Nottingham, United Kingdom, 2University of Nottingham, Sir Peter Mansfield Imaging Centre, Nottingham NG7 2RD, England, Nottingham, United Kingdom, 3Neurosurgery, Nottingham University Hospitals, Nottingham, United Kingdom |
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Chronic pain is a major problem for society and further studies are needed to understand pain-related developments. In particular, controversy exists over the pattern of pain-related structural changes in the brain. The current morphometric study addresses inconsistencies through a large sample of chronic osteoarthritis knee pain patients and healthy volunteers scanned at a single-site, allowing to differentiate sex effects which are usually ignored. We found significantly decreased gray matter density in pain patients in several brain regions, amongst which the left planum temporale which was driven by the female subjects and has not been mentioned in relation to pain before. |
| 2564 | Brain Structural Alterations in Obese Adults with Impulsive Personality Traits: A Voxel-Based Morphometry Study | |
1Department of MRI, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China, 2MR Research China, GE Healthcare, Beijing, People's Republic of China, 3Peking University, Beijing, People's Republic of China |
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This study used voxel-based morphometry method to examine gray matter volume alterations related to impulsive personality traits in obese individuals relative to controls. 62 adolescents completed the UPPS-P Impulsive Behavior Scale were analyzed. Possible GM volume alterations were firstly analyzed at the whole brain range. The relationship of regional GM volumes with UPPS-P scores were examined in selective regions of interest. This study demonstrated that sensation seeking behavior in obese people negatively correlate with GM volumes of amygdala, OFC, hippocampus, and insula indicate high sensitivity to food cues in adult obesity that link to certain alternations of the brain structure. |
| 2565 | Evaluation of Whole Brain and ZOOMit T1-weighted Turbo-Spin Echo (TSE) for Visualization of Human Lenticulostriate Arteries at 3.0 T: A Preliminary Study | |
1Neurology, University of Southern California, Los Angeles, CA, United States |
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Cerebral small vessel disease frequently affects the lenticulostriate arteries, resulting in silent strokes which contribute to progressive cognitive impairment in elderly persons. Recent studies have demonstrated the ability of MRI to non-invasively image these small arteries at 7T; however, ultrahigh magnetic field is not commonly available in clinical practice. This preliminary study evaluates the feasibility of visualizing and characterizing the lenticulostriate arteries using whole-brain and ZOOMit 3D T1-weighted turbo spin-echo at 3T. |
| 2566 | See It, Slice It, Learn It: Combined Ultra High Field MRI and High-resolution CT for an Open Source Virtual Anatomy Resource | |
1Melbourne Brain Centre Imaging Unit, Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia, 2Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia, 3Harry Brookes Allen Museum, Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia, 4Learning Environments, University of Melbourne, Parkville, Australia, 5Siemens Healthcare, Melbourne, Australia |
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Grasping human head and neck anatomy can be challenging for students, scientists and health professionals in medical disciplines. Ultra-high field, 7T MRI can create high-resolution images with multiple contrasts, revealing structural detail not easily apparent in dissection specimens. While widely exploited in clinical and scientific studies, its use has been limited so far in creating tools for medical education. We present a multi-modal combination of ex-vivo MRI and CT to create a high-quality head and neck anatomy resource to enhance cadaveric cross-sectional anatomy teaching. |
| 2567 | MRI Characterization of Cerebellar Atrophy in a Non-Human Primate Model of Neuronal Ceroid Lipofuscinosis | |
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, 2Pathology, Oregon National Primate Research Center, 3Primate Genetics, Oregon National Primate Research Center, 4Oregon National Primate Research Center, 5VGTI, Oregon National Primate Research Center, 6Clinical Medicine, Oregon National Primate Research Center |
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Neuronal ceroid lipofuscinosis (NCL; also known as Batten Disease) is a fatal neurodegenerative disorder that typically presents in childhood. Currently, no treatments are known that can halt or reverse the effects of NCL. A naturally occurring form of NCL analogous to late infantile-onset NCL in humans has been identified in a population of Japanese macaques (JMs). MRI examinations revealed marked cerebellar degeneration in NCL animals >4y/o (~14y/o equivalent human age) compared with controls, which is strikingly similar to human disease. This novel JM model presents a new opportunity for characterizing disease progression, identifying biomarkers, and pre-clinical therapeutic testing. |
| 2568 | A Pseudo-Longitudinal Study of the Lifespan Neuroanatomical Changes based on a Large-scale Imaging Data | |
1Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, Hong Kong, 2Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing, People's Republic of China, 3Research Center for Medical Image Computing, Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, Hong Kong, 4Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China |
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Understanding how brain changes over the lifetime provides the basis for new insights into neurophysiology and neuropathology. In this study, we carried out a pseudo-longitudinal study based on large-scale cross-sectional high-resolution brain MR data atlas Chinese2020 to model the brain morphological changes in Han Chinese adulthood. Our results found some novel age-related neuroanatomical changes in a standardized brain space via temporal-spatial statistical brain templates. |
| 2569 | Assessment of brain volume and shape abnormalities in chemotherapy-treated breast cancer survivors using voxel-based morphometry and vertex-wise shape analysis | |
1Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, 2School of Medicine, Chang Gung University, Taoyuan, Taiwan, 3Department of Psychiatry, Chang Gung Memorial Hospital, Chiayi, Taiwan, 4Breast Center, Taichung Tzu Chi Hospital, Taichung, Taiwan, 5Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan |
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Cancer-related trauma after chemotherapy has been widely reported by breast cancer. The previous study consistently showed lower gray and white matter volume and density in patients treated with chemotherapy. The aim of this study was to find out the early effect in both brain volume and shape in the chemotherapy-treated breast cancer patients compared to healthy controls using voxel-based morphometry (VBM) and vertex-wise shape analyses, respectively. Our results showed significant changes in the brain structural volume and shape, particularly in the putamen and hippocampus. |
| 2570 | High‑resolution Magnetic Resonance Imaging of Basilar Artery with Iterative Decomposition of Water and Fat with Echo Asymmetric and Least-squares Estimation(IDEAL): A Feasibility Study | |
1Radiology, Renmin Hospital of Wuhan University, Wuhan, People's Republic of China, 2GE healthcare China, People's Republic of China |
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To explore the potential for high-resolution MR imaging using IDEAL FSE-T2WI as compared to FSE-T2WI in the assessment of the basilar artery wall. High-resolution FSE(A/P), FSE(R/L) and IDEAL FSE(A/P) T2W images were acquired from basilar artery of 30 patients using a 3.0T MRI scanner.The threeimage sets were evaluated for overall image quality and graded using a 4-point Likert scale.IDEAL FSE-T2WI (A/P) scores is higher than FSE-T2WI (A/P) and FSE-T2WI (R/L).FSE-T2WI (A/P), FSE-T2WI (R/L) andIDEAL FSE-T2WI (A/P) difference with statistical significance,respectively.IDEAL FSE-T2WI images showed improved image quality compared to FSE-T2WI technique at 3T. |
| 2571 | Mapping the Neurological Effect of Soman, a Chemical Warfare Nerve Agent, using 9.4T MRI | |
1Radiology, University of Calgary, Calgary, AB, Canada, 2National Defence, Defence Research And Development Canada, Suffield, AB, Canada |
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Soman is a chemical warfare nerve agent that is categorized as a weapon of mass destruction. Nerve agents are potent irreversible inhibitors of acetylcholinesterase and exposure can be extremely lethal. At a sub-lethal dose, our understanding of the neurological effect is limited. To understand the soman associated physiological changes, MRI was used to quantify the cerebral blood flow after a convulsive dose of soman. |
| 2572 | Direct Localization Human Pedunculopontine Nucleus Using 7T, Coordinate and Fiber Tracking Validation | |
1State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, People's Republic of China, 2Graduate University, Chinese Academy of Sciences, Beijing, People's Republic of China, 3Department of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, People's Republic of China |
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The pedunculopontine nucleus (PPN), as a potential Deep brain stimulation (DBS) target for the patients to improve gait and posture. Until now, only a few results of the location of PPN has been published. In this study, 7T ultra-high field MR system and high resolution MP2RAGE sequence were used to locate the PPN by a direct view, manually measurement and fiber tracking method were used to verify the results. The results showed a clear and accurate location of PPN. |
| 2573 | Spatial Patterns of Intersubject CBF Variability in the CARDIA study | |
1Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China, 2Department of Neurology, School of Medicine, University of Pennsylvania, 3Department of Radiology, School of Medicine, University of Pennsylvania, 4Departments of Neurology and Radiology, School of Medicine, University of Pennsylvania |
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Variability in regional relative cerebral blood flow (CBF) from resting-state arterial spin labeling (ASL) MRI data obtained in a large (N=436) cohort were examined using spatial Independent Components Analysis (ICA). Some spatial patterns of intersubject CBF variability resembled known resting-state functional networks, and were largely reproducible across split samples. Network relative CBF fluctuation across subjects was about 14%. |
| 2574 | Performance of Complex Tasks of Working Memory Related to Brain Microstructure in Healthy Adults: a Diffusion Kurtosis Imaging 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 School of Medicine, New York, NY, United States |
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The relationship between performance on working memory tasks of increasing difficulty and white matter (WM) microstructure assessed by diffusion kurtosis imaging (DKI) is investigated in a healthy adult population. We demonstrate that higher mean kurtosis (MK) and radial kurtosis (RK) correlate with performance on working memory tasks, particularly in frontal WM, an area responsible for executive function, suggesting better working memory performance with higher tissue complexity in frontal WM. Improving our understanding of these associations will help determine the biological underpinning of pathologies affecting cognition, as well as potentially informing and monitoring interventions such as cognitive rehabilitation. |
| 2575 | Altered Diffusion Tensor Anisotropy Rather Than Morphology in the Corpus Callosum after Lower Limb Amputation | |
1Radiology, Southwest Hospital, Third Military Medical University, Chongqing, People's Republic of China, 2MR Collaboration, Siemens Healthcare Ltd, Shanghai, People's Republic of China |
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We examined morphological and diffusion changes of the corpus callosum (CC) in the same group of amputees for the first time. The thickness, area and diffusion tensor imaging (DTI) parameters were used to investigate the CC. Diffusion alteration in the region II of the CC was found in amputees compared with health controls. These changes suggest that fibers connecting bilateral premotor and supplementary motor areas are damaged. The alteration is only reflected in DTI parameters rather than morphological characteristics, indicating that DTI is more sensitive to detect the brain reorgnization following amputation. |
| 2576 | MR Imaging of tissue near aneurysm clips using short- and zero echo time MR sequences | |
1Biological Resources Imaging Laboratory, UNSW, Australia, Mark Wainwright Analytical Centre, Sydney, NSW, Australia, 2Central European Institute of Technology, Masaryk University, Brno, Czech Republic, 3Department of Neurosurgery, University of Vienna, Vienna, Austria, 4Department of Oncology, Division of Medical Physics, University of Alberta, Edmonton, AB, Canada |
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Aneurysm clips are used to stop or prevent an aneurysm from bleeding. MRI is an ideal technique to diagnose aneurysms. Unfortunately, treatment assessment by MRI after surgical placement of an aneurysm clip is complicated due to the presence of the metal clip. The clip's high magnetic susceptibility causes severe, orientation dependent, variations in the local magnetic field. Often this results in pronounced MR image distortions including signal voids. The study presented here shows how ultra-short and zero echo time experiments could be used to minimize these artifacts. |
| 2577 | MRI compatible Set up for Optogenetic Stimulation of Living Brain Slices | |
1Champalimaud Neuroscience Programme, Champalimaud Centre for the Unkown, Lisbon, Portugal |
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Organotypic slices are excellent controlled systems for investigating neural activity without many of the confounds introduced by in-vivo conditions. Here we describe a new setup that allows imaging of a living slice inside a MRI scanner while being stimulated with optogenetics which induces neuronal activity in pre-targeted neurons. This setup allows the survival of slices for at least three hours, without requiring new artificial CSF (aCSF) to be flushed. This property is highly advantageous for avoiding artifacts related with bubbles, motion or variation of shims during extended acquisitions. |
| 2578 | Myelin Density Measurement by ZTE in the D2O-Exchanged Spinal Cord is Unaffected by Tissue Fixation | |
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, 3Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 4Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 5Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States |
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Zero echo time imaging (ZTE) of deuterium oxide (D2O)-exchanged unfixed white matter is a proven method for measurement of myelin density. In this work, we perform D2O-exchanged ZTE measurements on human spinal cord tissue before and after formalin fixation to assess whether fixation, which cross-links proteins, impacts the measured myelin density. A segment of human spinal cord was obtained at autopsy, subjected to D2O-exchanged ZTE myelin density measurement, chemically fixed using formalin, and re-measured. Signal intensity was 31.36%, normalized to a reference, before fixation, and 31.44% after fixation. These similar measurements support this method’s accuracy in fixed tissue. |
| 2579 | Investigating the effect of a tight necktie on arterial cerebral blood flow and venous flow velocity | |
1Clinic for Neurology, University Hospital Schleswig-Holstein, Kiel, Germany, 2Clinic for Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Kiel, Germany |
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Wearing a necktie is mandatory in several professions. However, the constant restriction of the veins (and potentially arteries) might lead to adverse side-effects, which could already be visualized regarding intraocular pressure. In this study, the effects of a tight necktie are investigated using Arterial Spin Labeling to measure brain perfusion and venous phase-contrast angiography to show changes in venous flow velocities. |
| 2580 | Reproducibility and Age dependence of GluCEST contrast in healthy adults | |
1CMROI, Radiology, Perelman School of Medicine at The 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 |
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In this study we employed the single-slice 2D glutamateCEST (GluCEST) MRI to measure the reproducibility as well as changes in GluCEST with age in healthy human brains. GluCEST MRI appears to be a promising technique that can characterize neuronal changes in normal aging. |
| 2581 | Altered brain gray matter volume and cerebral blood flow in patients with type 2 diabetes mellitus | |
1Medical Imaging Center, The First Affiliated Hospital of Jinan University, Guangzhou, People's Republic of China, 2MR Research China, GE Healthcare, Beijing |
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Patients with type 2 diabetes mellitus (T2DM) and there relatives with high risk of diabetes both demonstrate atrophy in right temporal and left insular lobesin. Furthermore, the decrease of cerebral blood flow (CBF) was more popular in the right temporal lobe for high risk group other than T2DM patients |
| 2582 | Comparison of CSF Flow Imaging Methods | |
1Radiology, Children's Hospital Los Angeles, Los Angeles, CA, United States, 2Rudi Schulte Research Institute, Santa Barbara, CA, United States, 3Neonatology, Children's Hospital Los Angeles, Los Angeles, CA, United States, 4Radiology, Children's Hospital Los Angeles, CA, United States, 5Radiology, University of Southern California, CA, United States, 6Neurosurgery, Children's Hospital Los Angeles, Los Angeles, CA, United States, 7Radiology, Children's Hospital Los Angeles, CA, 8Rudi Schule Research Institute, Santa Barbara, CA |
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We compared the quality of CSF flow images of ten subjects acquired with T2-weighted flow-void, phase-contrast, and tag-based MR methods. Tag-based methods included the variable image contrast TimeSLIP sequence and a newly designed method, termed TimeSTAMP, with constant contrast. Five radiologists and one neurosurgeon rated them on usefulness for identifying flow with a Likert scale: 5=highest to 1=lowest. Flow was detectable with high confidence for TimeSLIP and TimeSTAMP (4.8 ± 0.2), confidence was significantly lower (p<0.0001) in flow-void (2.5 ± 0.7) and phase-contrast (2.6 ± 0.5) images. |
| 2583 | The value of 7T in the clinical evaluation of epileptic patients with tuberous sclerosis complex | |
1State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, People's Republic of China, 2University of Chinese Academy of Sciences, Beijing, People's Republic of China, 3Chinese PLA general hospital, Beijing, People's Republic of China, 4Beijing Tian Tan Hospital, Capital Medical University, Beijing, People's Republic of China |
||
Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disease. 90% of patients with TSC suffer from epilepsy and 50% of them become medicine intractable epilepsy. Epilepsy surgery is an important treatment. However, some focal epileptogenic lesions, essential for surgery, are not well identified by current routine imaging protocols at 3T. 7T MR imaging is assessed in this study to allow better characterization of lesion details and to detect abnormalities previously unseen on 3T MRI and scalp electroencephalogram (EEG). This is the first report of clinical application of 7T MRI for pediatric patients (older than 8 years) with TSC epilepsy. |
| 2584 | Functional neuroimaging using dynamic radial 3D UTE pulse sequences | |
1Gordon Center for Medical Imaging, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States, 2Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 3Radiology, Stony Brook University, Stony Brook, NY, United States, 4Psychiatry, Stony Brook University, Stoney Brook, NY, United States, 5Nanomedicine Science and Technology Center, Northeastern University, Boston, MA, United States |
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Functional MR neuroimaging is an essential tool for studying brain activity. Cerebral blood volume (CBV) is an important indicator of brain function, but measurements are typically qualitative or relative. Furthermore, warping and signal drift necessitate significant image pre-processing with standard EPI acquisition. In this work, we utilize a radial 3D UTE pulse sequence with optimized acquisition parameters determined from phantoms and modeling. Feasibility of dynamic UTE as a functional neuroimaging method is demonstrated in non-human primates receiving NBOH-2C-CN, a 5-HT2A receptor agonist. CBV is measured dynamically throughout the whole brain and shown to agree well with an analogous EPI experiment. |
| Exhibition Hall | Wednesday 16:15 - 18:15 |
| 2585 | Percutaneous MRI-Guided Cryoablation of Regional Nodal Metastases in Prostate Cancer: Initial Experience | |
1Mayo Clinic, Rochester, MN, United States |
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In this retrospective study, we examined the feasibility and safety of magnetic resonance imaging (MRI)-guided percutaneous cryoablation of regional nodal metastases in the setting of prostate cancer. The study cohort comprised eight patients with biochemically recurrent prostate cancer who had undergone prior prostatectomy and radiotherapy, thereby limiting their ability to receive further radiation to regional nodes. Technical success was achieved in all cases and there were no procedure-related complications. Our data suggest that MRI-guided cryoablation offers a feasible alternative therapy for local control of metastatic lymph nodes. Further prospective investigation is warranted to assess short- and long-term local efficacy. |
| 2586 | Orientation-independent z-shimmed temperature mapping near ablation probes | |
1Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 2Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States |
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MR guidance of thermal ablation is hindered by signal loss around the metallic applicators and needles used to deliver treatment. This signal loss can prevent accurate MR thermometry in the area of critical heating around the ablation probe. Here we present a multiple-echo z shimmed sequence with optimized refocusing scheme that can correct for through-plane distortion from the probe irrespective of probe and slice orientations. With the chosen refocusing scheme we achieved a signal recovery of 10 to 1 in the near-probe region when compared to a conventional gradient echo thermometry technique. |
| 2587 | Hybrid MR-ultrasound acquisition for multi-baseline thermometry | |
1Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States |
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MR thermometry, based on proton resonance frequency (PRF) shift, can be achieved by the phase subtraction between pretreatment baseline images and treatment images. However, breathing motion leads to phase errors that may corrupt temperature measurements. We propose the use of a hybrid MR-ultrasound imaging setup and reconstruction algorithm to provide the phase reference required for PRF thermometry in moving organs. The generated synthetic MR-ultrasound images match the acquired images in all respect except for the fact that they do not contain any heating information, and thus provide a valuable non-heated phase reference from which temperature changes can be quantified. |
| 2588 | Comparison of Temperature Mapping Methods Using Proton Resonance Frequency Shift and T1 in 3-T and 7-T MRI | |
1Department of Electronics and Information Engineering, Korea University, Seoul, Korea, Republic of, 2ICT convergence technology for Health & Safety, Korea University, Sejong, Korea, Republic of, 3Bioimaging Research Team, Korea Basic Science Institute, 4Research Institute for Advanced Industrial Technology, Korea University, Sejong, Korea, Republic of |
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Although temperature imaging in 7.0 T MRI has the advantage of increased SNR compared to lower field, it is more sensitive to susceptibility causing more artifacts. Since the 7.0 T MRI is also affected more by the electrical conductivity, temperature-dependency of the electrical conductivity is also affecting the resultant images. This work compares the temperature mapping methods for RF hyperthermia in 7.0 T and 3.0 T MRI and proposes the new temperature mapping method appropriate to 7.0 T MRI under the environment of changing conductivity. |
| 2589 | Dynamic anti-aliasing image reconstruction for localized thermal therapies | |
1Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States |
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A novel image reconstruction algorithm for dynamic anti-aliasing image reconstruction (DAIR) of proton resonance frequency shift (PRFS) MR temperature maps from subsampled k-space data for localized heatings is presented. DAIR makes use of a pre-heating, fully sampled image to find and remove the aliasing artifact in a dynamic series of images. The algorithm is demonstrated using CAIPI-like sampling patterns in a 3D segmented EPI pulse sequence and focused ultrasound heatings in a tissue mimicking gelatin phantom. DAIR reconstructed PRFS temperature maps showed good agreement with fully sampled “truth” for k-space reduction factors of 2 – 4. |
| 2590 | An Adaptive Non-Local Denoising Method for Real-Time MR-Thermometry | |
1University Medical Center Utrecht, Utrecht, Netherlands, 2University of Bordeaux, Bordeuaux, France |
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MR-guided targeted thermal therapies often rely on temperature information provided by proton resonance frequency shift (PRFS) thermometry. However, fast MR acquisition schemes are usually employed, in order to provide temperature updates with a short latency. This may lead to noisy temperature measurements, which can have a direct impact on therapy control and monitoring. In the current study we propose a novel non-local denoising technique for real-time MR-thermometry that improves data precision, while at the same time maximizing output accuracy, feature which is not guaranteed by currently employed real-time MR-temperature denoising methods. |
| 2591 | Fast Temperature Estimation Using Golden Angle Radial from Undersampled K-Space for MR Guided Microwave Ablation | |
1Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China, 2Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China, 3Department of Orthopedics, First Affiliated Hospital of PLA General Hospital, Beijing, People's Republic of China, 4Key Laboratory of Particle and Radiation Imaging, Ministry of Education, Medical Physics and Engineering Institute, Department of Engineering Physics, Tsinghua University, Beijing, People's Republic of China |
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Golden angle radial sampling is insensitive to motion and provides oversampled central k-space for self-navigation. This study aims to accelerate the acquisition with motion correction for MR temperature imaging by applying golden angle radial to hybrid model based on PRF method. The proposed method uses low resolution images obtained from a certain ratio of radius in k-space center to correct the period motion and magnetic field drift. Then, an iterative method is adopted to estimate the temperature by the hybrid model. Simulations and in-vivo experiments demonstrate the robustness to motion and effectiveness of the proposed method. |
| 2592 | Prospective Motion Correction of MR-Thermometry using an Optical Tracking System | |
1Department Biomedical Magnetic Resonance, Magdeburg, Germany, 2Chair of Electromagnetic Compatibility, Institute of Medical Engineering, 39106, Germany, 3Institute of Neuroradiology, Magdeburg, Germany, 4Department of Radiology, Hannover Medical School, Hannover, Germany |
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Accurate temperature assessment during liver ablation requires a dedicated method for motion correction. We present the first results of a prospective motion correction method for thermometry during microwave ablation using an optical Moiré Phase Tracking system. Ex-vivo studies showed a mean temperature deviation of ΔT = 0.4 °C compared to ΔT = 34.6°C without motion correction. The method can easily be integrated into the work flow if optical tracking is applied for needle placement. |
| 2593 | Accumulated Thermal Dose in MR-Guided Focused Ultrasound for the Treatment of Essential Tremor | |
1Sunnybrook Research Institute, Toronto, ON, Canada, 2Division of Neurosurgery, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 3Division of Neurosurgery, Toronto Western Hospital, Toronto, ON, Canada, 4Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada |
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In focused ultrasound treatment of essential tremor, MR temperature and thermal dose measurements were crucial in guiding acoustic parameters. In this study, accumulated thermal doses from repeated sonications were integrated after chemical-shift artifacts were corrected retrospectively. Accumulated thermal dose measurements showed good correlation to lesion size in followup MR imaging. |
| 2594 | Effects of ultrasound transducer ground plane configuration on SNR in MR guided focused ultrasound therapies | |
1UCAIR, University of Utah, Salt Lake City, UT, United States |
||
The use of dedicated RF coils can increase image SNR in magnetic resonance guided focused ultrasound (MRgFUS). However, shielding and eddy current effects of the ultrasound transducer ground plane (TGP) can significantly degrade the increased SNR. Accounting for these considerations when designing the ultrasound transducer can potentially increase SNR throughout the imaging volume during MRgFUS procedures. |
| 2595 | In Vivo 19F MRI for Non-invasively Investigating the Effects of Perfluorocarbon Nanoemulsion on High Intensity Focused Ultrasound Tumor Ablation | |
1Molecular Imaging & Therapy Branch, National Cancer Center, Goyang, Korea, Republic of, 2Dept. of Radiology, Seoul National University Hospital, Seoul, Korea, Republic of |
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Perfluorocarbon nanoemulsion (PFCNE) is currently studied as a precursor of microbubbles to accompany high intensity focused ultrasound (HIFU) for tumor ablation. We propose 19F MRI as a valuable tool for non-invasively assessing the effects of PFCNE concentration on therapeutic efficiency of HIFU. 19F MRI was used to determine the amount of PFCNE accumulated in a tumor before HIFU treatment. Tumor ablation was monitored by intra-voxel incoherent motion (IVIM) mapping, which was compared with PFCNE quantification from 19F MRI for identifying the PFCNE concentration that gives optimal therapeutic efficiency. |
| 2596 | Automatic removal of water bath artifacts from MR temperature maps in focused ultrasound neurosurgery | |
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, 2Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, 3Center for MR-Research, University Children's Hospital, Zurich, Switzerland |
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During MR-guided focused ultrasound treatments in the brain, circulation of cool water around the head and ultrasound wave propagation create water motion during the signal readout, resulting in image artifacts. These artifacts vary across image dynamics, and are observable in magnitude and phase images and in temperature change maps measured during treatment. In this work, we apply a wavelet denoising algorithm to remove these artifacts from temperature maps during treatment. Results show that temperature errors can be corrected in patient data, in 0.2 s per map, suggesting that corrections could be performed during treatment. |
| 2597 | The Treatment Outcome of Magnetic Resonance guided High Intensity Focused Ultrasound Ablation of Uterine Fibroids through the Transverse and Longitudinal Scars | |
1MR Therapy, Philips Healthcare, Seoul, Korea, Republic of, 2Department of Radiology, Pham Ngoc Thach University of Medicine, HCMC, Vietnam, Ho Chi Mihn City, Vietnam |
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This study investigates the technical treatment success and therapeutic efficacy of magnetic resonance guided high intensity of focused ultrasound (MR-HIFU) ablation of uterine fibroid patients with transverse and longitudinal scars. The results of the present study suggests that the scar patch could be used in MR-HIFU ablation of fibroid patients with transverse and longitudinal abdominal scars, which might no longer be regarded as an exclusion criterion. |
| 2598 | The Role of Perfusion MRI in Predicting Magnetic Resonance-guided High Intensity Focused Ultrasound Treatment Outcome in Uterine Fibroids | |
1MR Therapy, Philips Healthcare, Seoul, Korea, Republic of, 2Department of Radiology, Pham Ngoc Thach University of Medicine, HCMC, Vietnam, Ho Chi Mihn City, Vietnam |
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The aim of this present work is to classify uterine fibroids by comparing the MR T1 perfusion based time-signal intensity curves of fibroid tissue with myometrium prior to HIFU ablation. Our findings in this study suggest that the newly introduced classification method could be used as the primary MRI classification parameter prior to MR-HIFU ablation not only for classifying the uterine fibroids but also predicting the treatment outcome of HIFU ablation, with the immediate NPV ratio of at least 80%. |
| 2599 | Estimation of Focused-Ultrasound Induced CNS Molecular Delivery via Dynamic Contrast-Enhanced Magnetic-Resonance Imaging | |
1Department of Diagnostic Radiology and Intervention, Chang-Gung Memorial Hospital, Taoyuan, Taiwan, 2Department of Electrical Engineering, Chang-Gung University, Taoyuan, Taiwan, 3Department of Research and Development, NaviFUS corp., Taipei, Taiwan, 4Medical Imaging Research Center, Institute for Radiological Research, Chang-Gung University/Chang-Gung Memorial Hospital, Taoyuan, Taiwan, 5Medical Science and Technology, National Sun Yat-Sen University, Kaohsiung, Taiwan, 6Institute of Neuroscience and Technology, Zhejiang University, Zhejiang, People's Republic of China |
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Focused ultrasound (FUS) exposure with presence of microbubbles can transiently open the blood-brain-barrier (BBB) at targeted brain tissues. The purpose of this study is to investigate the feasibility to employ DCE-MRI to predict and estimate molecular CNS penetration under various exposure conditions and molecular sizes. Our result showed high accuracy and successful (prediction discrepancy was limited to be less than 10%) to estimate molecular penetration of FUS-induced BBB opening via imaging index (Ktrans) from DCE-MRI. This approach may bring technology advances and facilities the clinical application of FUS-induced BBB opening to deliver therapeutic molecules for CNS disease treatment. |
| 2600 | Detection of temperature induced viscoelasticity changes using MR acoustic radiation force impulse imaging | |
1Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States, 2Department of Radiology and Imaging Sciences, University of Utah, 3Department of Radiology, Stanford University |
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MR acoustic radiation force impulse (MR-ARFI) imaging, which measures tissue displacement caused by the concentrated force of a focused ultrasound (FUS) beam, has been used to locate and characterize the ultrasound focus. It has also been used to measure and assess changes in tissue elastic properties. We hypothesize that localized heating may denature elastic properties of tissues, and convert the elastic displacement caused by FUS to a form of viscous streaming. In this work, we propose using 3D GRE MR-ARFI with a unique timing scheme, to quickly and efficiently detect temperature induced viscoelasticity changes in a gelatin phantom during FUS heating. |
| 2601 | Quantification of Acoustic Radiation Force Induced Flow Velocity Changes by Phase-Contrast MRI | |
1Biomedical Engineering and Environment Science, National Tsing Hua University, Hsinchu, Taiwan, 2Electrical Engineering, Chang-Gung University, Taoyuan, Taiwan |
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We adopted phase-contrast MRI to real-time acquire flow velocity information with transmitting focused ultrasound pulses on microbubbles in a flowing phantom. We aim to evaluate the velocity changes resulted from the formation of bubbles by secondary acoustic radiation force. We observed that temporal standard deviation of velocity and %velocity change increased with increasing MBs concentrations. It can be attributed to the formation of aggregated bubbles, which can narrow the chamber diameter and accordingly lead to higher flow velocity. In conclusion, we verified the feasibility of using phase-contrast MRI to evaluate the impact of secondary acoustic radiation force. |
| 2602 | Design of 5-channel On-coil Shimming Coil for Rat Brain MRI Guided High Intensity Focused Ultrasound: a preliminary study | |
1Lauterbur Imaging Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen City, People's Republic of China, 2Department of Radiology and Biomedical Imaging, University of California San Francisco, CA, United States, 3UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, United States |
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Signal-to-noise ratio (SNR) and homogeneity of the static magnetic field B0 are critically important in achieving accurate temperature measurement for MRI guided HIFU. In this work, a 5-channel shimming coil on the top of a 3-channel RF coil array at 3T has been fabricated to increase the B0 homogeneity and the SNR in region of interest. Phantom studies have demonstrated the the capability of the proposed shimming coil to improve B0 homogeneity and SNR of the images, which will lead to accurate temperature mapping. |
| 2603 | System for Delayed Intervention in MRI | |
1Imperial College Healthcare NHS Trust, London, United Kingdom, 2Bioengineering, Imperial College London, London, United Kingdom |
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A system for Interventional MRI using Infrared tracking of a handeld needle guide was adapted for practical use in closed-bore scanners. This was achieved by mapping of the image space to a patient space with the table outside the scanner bore to permit delayed visualisation of the targeted site. This novel method enables manual intervention of complex sites to be handled with greater care than other methods, and provides a relatively low-cost option for MR-guided interventions. |
| 2604 | Radiofrequency applicator concepts for simultaneous MR imaging and hyperthermia treatment of glioblastoma multiforme: A 7.0 T (298 MHz) study | |
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, 2MRI.TOOLS, Berlin, Germany, 3Clinic for Radiation Oncology, Charité Universitätsmedizin, Berlin, Germany, 4Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany |
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Glioblastoma multiforme is the most frequent and most aggressive malignant braintumor with de facto no long term curation by the use of current multimodal therapeutic approaches. RF heating at ultrahigh fields (B0=7.0T, f=298MHz) has the potential of delivering sufficiently large thermal dosage for hyperthermia of relatively large tumor areas. This work focuses on EMF simulations and provides realistic applicator designs tailored for simultaneous RF heating and MR imaging. Our preliminary results suggest that RF power can be focused to both a small tumor area and a big clinical target volume based on segmented patient data. |
| 2605 | Stepwise optogenetic activation of the rat thalamic nuclei with MRI-guided robotic arm (MgRA) | |
1Research Group of Translational Neuroimaging and Neural Control, High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 2Graduate School of Neural Information Processing, University of Tuebingen, Tuebingen, Germany |
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An MRI-guided multiple degree-of-freedom robotic arm positioning system is developed to guide the fiber optic insertion inside a small animal MRI scanner. The fiber optic is positioned at different depth in the rat thalamus to deliver light pulses for optogenetic fMRI. The corresponding functional spatial patterns and time courses can be achieved in a stepwise manner. The MgRA positioning system provides an alternative way to study global functional projections by mapping fMRI signals driven optogenetically from different brain nuclei. |
| 2606 | Clinical Outcome of Globus pallidus internus or subthalamic nucleus deep brain stimulation for Parkinson's disease using MRI-guided localization and verify with microelectrode | |
1Department of Radiology & Imaging, Queen Elizabeth Hospital, Kowloon, Hong Kong, 2Department of Neurosurgery, Queen Elizabeth Hospital, Kowloon, Hong Kong |
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Globus pallidus internus (GPi) and Subthalamic nucleus (STN) are the two main target for deep brain stimulation (DBS) in treatment for patients with advanced Parkinson's disease (PD) not respond to medical therapies. MRI brain imaging is used for selection of patients for DBS and localize the target nucleus. This study confirms that GPi/STN-DBS may be placed with high accuracy by using a correct and optimal MRI-guided sequences. Correct deep brain stimulation electodes placement can provides a safe and effective treatment for severe Parkinson’s disease not responsive to medical therapies. |
| 2607 | MRI-based Synthetic CT for Radiation Treatment of Lung Cancer | |
1Department of Radiation Oncology, 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, 3Siemens Healthcare GmbH, Erlangen, Germany |
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With emerge of MR-linear accelerator technology, the interest for MR-only radiotherapy is growing rapidly. This study evaluated the feasibility of using pseudo-CT generated from conventional Dixon-MR scans for treatment planning of lung cancer where dosimetric differences are expected to be high due to tissue inhomogeneity. A model-based method including spine was applied to generate synCT from whole-body Dixon-MR data. The plans for radiotherapy in lung cancer calculated on synCT images closely agreed with the doses computed on standard CT to within 1%. Further evaluation of the MR-based treatment planning in a large patient cohort is needed. |
| 2608 | Abdominal organ tracking on a hybrid MR-Linac system using a particle filter based algorithm | |
1Département de radio-oncologie, Centre Hospitalier de l'Université de Montréal, Montréal, QC, Canada, 2Département de physique, Université de Montréal, Montréal, QC, Canada, 3Imaging division, UMC Utrecht, Utrecht, Netherlands, 4Radiation Oncology, Medical College of Wisconsion, Milwaukee, WI, United States, 5Radiology, Medical College of Wisconsin, Milwaukee, WI, United States |
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We have previously developed an autocontouring and tracking algorithm for lung tumors as an online application for MR-Linac treatments. This algorithm is now extended to abdominal organs tracking and evaluated with a range of imaging strategies on multiple systems, including single slice dynamic time-series data acquired on the 1.5T Marlin system of the MR-Linac as well as simultaneous multi-slice (SMS) and simultaneous orthogonal plane imaging (SOPI) acquired on diagnostic 1.5T Philips and 3T Siemens scanners. The wide adaptability of the algorithm on images of different contrast concludes that the method is robust and can be successfully applied in different tracking scenario. |
| 2609 | Visualization of Intracranial Aneurysms Treated with Low-profile Visualized Intraluminal Support (LVIS Jr. stent) Using Ultrashort Echo Time Magnetic Resonance Angiography | |
1Department of Radiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan, 2Department of Radiology, Juntendo University Hospital, Tokyo, Japan, 3Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan, 4Department of Neuroendovascular Therapy, Juntendo University School of Medicine, Tokyo, Japan |
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In this study, we evaluated the usefulness of ultrashort echo time magnetic resonance angiography (Silent MRA) for intracranial aneurysms treated with LVIS Jr. stent-assisted coil embolization by a comparison between silent MRA and three-dimensional time of flight MRA (3D TOF-MRA) because the LVIS Jr. stent had higher metal coverage than previous reported stents. In silent MRA, the score of flow in the stents was superior to that of 3D TOF-MRA (p<0.05). Moreover, aneurysm occlusion status was good agreement for DSA. Therefore, silent MRA might be useful for intracranial aneurysms treated with LVIS Jr. stent-assisted coil embolization. |
| 2610 | Feasibility of Zero TE MR based Radiation Therapy Planning for Head and Neck application | |
1GE Global Research, Munich, Germany, 2Department of radiation sciences, Umeå University, Umeå, Sweden, 3GE Healthcare, Danderyd, Sweden |
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We describe a method to convert Zero Echo Time (ZTE) MR images into synthetic CT at the resolution required for Radiation Therapy (RT). The method was tested for the head and neck application on N=8 patient data. The dose was calculated with a RT planning software and the results were compared relative to co-registered CT data. |
| 2611 | Active catheter tracking for MR-Guided Percutaneous Coronary Intervention at 3T: Initial Results in a Pig Model | |
1Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Freiburg, Germany, 2Department of Cardiology and Angiology I, University Heart Center, Freiburg, Germany, 3MaRVis, Frechen, Germany |
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Compared to X-Ray fluoroscopy, cardiovascular interventions under MR-guidance do not use ionizing radiation, they provide excellent soft tissue contrast, cross-sectional imaging in arbitrary slice orientations and a variety of functional measurement techniques. MR-guided catheterization of coronary arteries has so far only been demonstrated in animal trails at 1.5T, and it remains challenging due to limited temporal and spatial resolution. Also, dedicated instruments for MR-guided coronary interventions are not yet widely available. We show that active visualization of commercial catheters for MR-guided percutaneous coronary in a pig model at 3T is feasible and enables engagement of the LCA under real-time imaging. |
| 2612 | Artifact-reduced imaging of biopsy needles with 2D multi-spectral imaging | |
1Radiology, Stanford University, Stanford, CA, United States |
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MR-guidance for biopsy procedures features high intrinsic soft-tissue contrast. However, artifacts induced by the metallic needle can reduce the localization of the needle and require low susceptibility needle materials with poorer cutting performance. In this work, we explore 2D multi-spectral imaging (2DMSI) for reducing the needle artifacts for more precise needle localization and tracking or to enable the usage of conventional stainless-steel biopsy needles. |
| 2613 | MRI of Intra-Tumoral Iron-Oxide Labeled Clostridium novyi-NT Injections During Bacteriolytic Therapy in Solid Tumors | |
1Northwestern University, Chicago, IL, United States |
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Bacteriolytic therapy with Clostridium novyi-NT has shown promise as a form of cancer treatment, but concerns remain regarding route of delivery and toxicity. Our study aimed to develop a method to visualize delivery with MRI during bacteriolytic therapy. We did so by incubating bacteria with iron oxide particles. In vitro viability studies and labeling efficiency studies were then performed, followed by phantom studies. Bacteria were then directly injected into rat liver tumors as well as mouse flank tumors and imaged. We demonstrate that the labeled bacteria can be directly visualized on MRI and is a reliable indicator of successful delivery. |
| 2614 | Real-time lesion targeting during MRI-guided prostate biopsy using an iPad: feasibility and initial clinical evaluation | |
1Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, Netherlands, 2MIRA Institute for Biomedical Engineering and Technical Medicine, University of Twente, Enschede, Netherlands |
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Our study assessed the feasibility of a novel method for real-time lesion targeting during transrectal in-bore MRI-guided prostate biopsy using a tablet device inside the MR room. Real-time targeting was technically successful in all patients and allowed targeted biopsy of the cancer suspicious region without requiring additional needle guide adjustments in all but one patient. Prostate cancer (PCa) was found in 18 of 20 patients. Our initial clinical experience indicates a substantial decrease in biopsy and procedure time as compared to standard targeting, which could be valuable to increase clinical applicability of the technique. |
| 2615
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2D UTE-based MR thermometry of frozen tissue: feasibility during in vivo MRI-guided cryoablation | |
1Radiology and Nuclear Medicine, Radboud University Medical Centre, Nijmegen, Netherlands, 2Radiology - Medical Physics, Medical Center University of Freiburg, Freiburg, Germany, 3Urology, Radboud University Medical Centre, Nijmegen, Netherlands, 4MIRA Institute for Biomedical Engineering and Technical Medicine, University of Twente, Enschede, Netherlands |
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This study assessed the feasibility of 2D UTE-based MR thermometry of frozen tissue during in vivo MRI-guided cryoablation. Axial 2D UTE images were acquired at the end of the first and second freeze cycle during an MRI-guided renal cryoablation procedure. Measurable MR signal could be obtained from frozen tissue. MR temperature maps were estimated using a relative signal level calibration performed in ex-vivo porcine muscle. Our work demonstrates the feasibility of 2D UTE-based MR thermometry of frozen tissue during in vivo MRI-guided cryoablation, which could be an important step towards clinical application of this technique. |
| 2616 | Simultaneous slice excitation for accelerated passive marker tracking via phase-only cross correlation (POCC) in MR-guided needle interventions | |
1Dept. of Radiology, Medical Physics, Medical Center - University of Freiburg, Freiburg, Germany |
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Minimally invasive interventions benefit from image guidance during instrument positioning. To ensure high image quality, MR-guided interventions are preferably performed in closed bore systems using MR markers and passive tracking sequences to localize and monitor the interventional device. In this work we accelerate a passive marker tracking sequence designed for needle-guided procedures using a simultaneous multi-slice excitation. With this technique the acquisition time is reduced by 33%, which results in a higher temporal fidelity while maintaining targeting accuracy. |
| 2617 | Treatment for Spontaneous Intracranial Hypotension: First Experience with MRI Guided Percutaneous Blood Patch and Fibrin Injection. | |
1Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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MRI guided blood patch/fibrin injection (BFP) instead of CT BFP as treatment option for SIH, first case reported. Avoids radiation exposure, helpful for adolescents and women in reproductive age. Obviates CT myelography, decreasing risks, time, and making it available for patients with iodine allergy. Our case is a 26 yo female with SIH. Axial PD, Axial and Sagittal T2 HASTE were used for localization of dural ectasia. T2 HASTE MRI fluoroscopy was used for spinal needle placement at the T12-L1 epidural space and injection of 10cc autologous blood and 2 cc of fibrin. The result was improvement of symptoms. |
| 2618 | Multiparametric Comparison of Quantitative Susceptibility Mapping, R2*, and 89Zr-PET for Quantification of Targeted Magnetic Drug Therapy Biodistribution | |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States |
||
Targeted magnetic drug delivery could reduce toxicity of transarterial chemoembolization when used in combination with a magnetic filtration device, and accurate quantification is necessary. We utilized 89Zr-iron oxide nanoparticles (IONP) to evaluate quantitative susceptibility mapping (QSM), R2*, and 89Zr-PET uptake. Phantom evaluations demonstrated linear correlation between QSM, R2*, and 89Zr-PET/MR. Substantial increase in QSM and R2* was observed in a single hepatic lobe in a preliminary in vivo experiment after injection using MR only. These cross-validated techniques demonstrate a linear relationship between IONP concentration and QSM, R2*, and 89Zr-PET in vitro and show promise in assessing magnetic nanoparticle tracking. |
| Exhibition Hall | Wednesday 16:15 - 18:15 |
| 2619
|
Metallic taste perception at 7 Tesla: Influences of jaw position and ionic composition of saliva | |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, 2Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 3Institute of Radiology, University Hospital Erlangen, Erlagen, Germany |
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Up to 40% of subjects report metallic taste sensations when exposed to strong magnetic fields. Can the perception of metallic taste during an ultra-high field (UHF) examination be lessened and thus increase patient comfort? This study experimentally examines the influence of jaw position and ionic composition of saliva (salinity and acidity) on metallic taste perception. We found that simple changes in tongue and teeth positions as well as saline in the mouth decrease the metallic taste sensation during UHF exposure. Following the current trend to UHF applications, these findings allow for further insight regarding increased patient comfort and acceptance of UHF examinations. |
| 2620 | Gradient Heating of Bulk Metallic Implants | |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig und Berlin, Germany |
||
The temperature increase of an excised hip prosthesis was measured under exposure to the switched gradients of a clinical 3T scanner. For the acetabular cup, insulated or embedded in gelatin gel, temperature increases of ΔT=25.8 K and 3.8 K, respectively, were observed within 10 min. From the initial temperature increase of up to 110 mK/s a gradient-induced heating power of PG = 370 W/kg in adjacent muscle can be derived and this quantity's relation to local SAR is discussed. The results suggest that gradient-induced heating of bulk metallic implants cannot automatically be assumed to be negligible. |
| 2621 | Comparison of Laser Doppler Vibrometer and Accelerometer Measurements of MRI Gradient Field Induced Vibration in Conductive Materials | |
1Physics and Astronomy, Western University, London, ON, Canada |
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Measuring gradient field induced vibration is essential to determine the safety of medical devices in the MR environment. This study investigated vibrations measured both inside and outside the MRI to quantitatively compare the use of accelerometers and laser Doppler vibrometers in gradient field induced vibration testing. Measures were conducted as a function of frequency over the range applicable to MRI gradient coil operation. Results indicate measurements obtained with accelerometers are comparable with laser Doppler vibrometry. |
| 2622 | 3D dB/dt measuring bench design and building for safety assessment | |
1IADI, Université de Lorraine, Nancy, France, 2Healtis, Nancy, France, 3U947, INSERM, Nancy, France, 4CIC-IT 1433, University Hospital, Nancy, France |
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In this project, the goal was to build a 3D dB/dt measuring bench to map in the MR scanner gradients fields components and to detect critical positions for safety assessment. Such positions are mandatory to assess gradients induced vibrations worst cases as described in the ISO TS 10974. |
| 2623 | Applicability of lead electromagnetic model for an external wire with skin contact | |
1Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany |
||
We calculated the electromagnetic (EM) model of an external wire with an electrode that contacts human skin at 123.2 MHz and evaluated the influence of the electrode dimension as well as the distance between the wire and the human body on the EM model using an approximation of the human body by a single tissue flat phantom. Our case study provided a strong evidence that at 123.2 MHz there is no worst-case distance between a wire and a human body that maximizes the power deposition for any wire length or electrode width. |
| 2624 | Evaluation of a thermal dose based safety concept for 7T pTx coils | |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig und Berlin, Germany |
||
We propose a straightforward procedure to calculate thermal dose values (CEM43) from upper limit values of tissue temperatures utilizing T-matrix formalism. The procedure is evaluated for a 7T 8-channel transmit/receive (pTx) head coil using the RF power data of a long duration neuroscience MR session and a scenario when heating of eye tissue is worst. The proposed approach, as a generalization of the thermal dose concept for body coils, is capable to determine reliably the risk of excessive tissue heating when using pTx coils. |
| 2625 | Experimental and simulated distribution of the RF electrical field inside a birdcage coil | |
1Univ. Lyon, CREATIS ; CNRS UMR 5220 ; INSERM U1206 ; INSA-Lyon ; UJM-Saint-Etienne ; Université Lyon1, Villeurbanne, France, 2Univ. Savoie-Mont-Blanc, IMEP-LAHC, Le Bourget-du-Lac, France, 3Kapteos, Sainte-Hélène-du-Lac, France |
||
High-field MR systems bring additional safety issues regarding the patient. One of main concern is the heating effect caused by the high-frequency and high-power signals that can be picked up by the conductors. It is thus required to identify these regions and to quantify the electrical E-field knowing that it is proportional to the square of the temperature elevation. For a direct measurement, an optical probe was used to perform a mapping of the E-field distribution inside a birdcage of a preclinical MRI. Experiments and simulations were found similar with E-field concentrations mainly located close to the capacitors. |
| 2626 | Quantification and impact of lead coupling on RF-induced heating in MRI. | |
1Université de Lorraine, IADI, Nancy, France, 2INSERM, U947, Nancy, France, 3Healtis, Nancy, France, 4CHRU Nancy, France, 5INSERM, CIT-1433, Nancy, France |
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Patients carrying multiple leads like abandoned pacemaker leads are still denied MRI scans, as their situation is not currently covered by the existing safety guidelines. Therefore, to assess the impact of lead coupling regarding radiofrequency-induced heating, temperature measurements were performed on different types of simplified leads and coupling factors were introduced to quantify and evaluate the phenomenon. The lead coupling can have a significant impact on temperature and can either induce higher or lower temperatures compared to the case when the leads are alone, and thus should be considered in future MRI safety standards. |
| 2627 | An Inexpensive, Modular, DSP-based SAR Monitor for Multichannel Transmit Systems | |
1Electrical and Computer Engineering, University of Alberta, Edmonton, AB, Canada, 2Biomedical Engineering, University of Alberta, Edmonton, AB, Canada, 3Oncology, University of Alberta, Edmonton, AB, Canada |
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We describe a modular power (SAR) monitor for multichannel systems whereby both the forward and reverse power of each channel are sampled and averaged on a dedicated board. Each board houses an inexpensive microcontroller with built-in ADCs for sampling the output of two power detectors. The microcontroller is programmed to perform time averaging, forward-reverse power subtraction and threshold detection. Multiple boards communicate simultaneously with a graphical user interface on a host computer. |
| 2628 | Test medium derivation for the safety assessment of RF-induced heating of leaded cardio implants during 1.5-T MRI | |
1IT'IS Foundation, Zurich, Switzerland, 2Department of Information Technology and Electrical Engineering, ETH-Zurich, Zurich, Switzerland |
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It is a common practice that an equivalent mathematical model of an implant is used to estimate in vivo power deposition caused by RF-implant interactions. The model is often derived under in vitro conditions. We assess the suitability of test media for RF-induced heating model derivation at 64 MHz. Based on simple generic leaded-implants, our preliminary analysis shows that the test medium specified in ASTM 2182 (εr = 78, σ = 0.47 S/m) may be appropriate for the safety assessment of leaded cardio implants with respect to RF-induced heating. Future analysis shall include implants with diverse topology and increased realism. |
| 2629 | Test field diversification method for the safety assessment of RF-induced heating of AIMDs during 1.5-T MRI | |
1IT'IS Foundation, Zurich, Switzerland, 2Department of Information Technology and Electrical Engineering, ETH-Zurich, Zurich, Switzerland |
||
Elongated AIMD can pick up the RF-energy during MR exposure, and locally deposit the energy in the tissue near its vicinity --- typically near the conductive electrodes. Current experimental assessment strategy is capable to achieve only a limited set of AIMD exposure conditions. In this work, we outline a method by which the exposure conditions may be diversified during experimental testing. The feasibility of the method is evaluated for three generic implants. The RF-induced deposited power of the AIMD over more than 1000 exposure conditions was evaluated and approximately 20 dB dynamic range in the deposited power was achieved. |
| 2630 | Investigation of RF-induced heating of distal radius implant system | |
1MR:comp GmbH, Gelsenkirchen, Germany, 2Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, 3MRI-STaR GmbH, Gelsenkirchen, Germany |
||
At 64 and 127.7 MHz RF-induced heating on or near nine distal radius implant systems was investigated. The 3-D temperature distribution after 15 minutes continuous excitation was obtained for a plane wave incident field. For one implant, random trials followed by a gradient-based investigation revealed three screw configurations that resulted in a high maximum temperature rise. Due to the smooth outcome of random trials followed by a gradient analysis, even relatively small simulation numbers allowed to reveal the configuration with the highest temperature rise for a given incident electrical field. |
| 2631 | Smaller is better: Averaging mass considerations for the assessment of RF power deposition and MR safety of small implants | |
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, 2Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, 3MRI.TOOLS GmbH, Berlin, Germany |
||
Assessment of the specific absorption rate (SAR) is a crucial tool when investigating the MR safety of implants. For RF power deposition assessments, local SAR averaged over m=10g of tissue is standard. Given the density in the human body (ρ≈1g/cm³), this translates into a volume of ≈2x2x2cm³, which largely exceeds the size of many small implants and bears the risk of heavy underestimation of local peak SAR. Realizing these constraints together with the opportunities, we investigated discrete SAR averaging masses from mave=1g to mave=0.01g to define SAR averaging masses suitable for the safety assessment of small implants. |
| 2632 | Characterization of gradient-induced vibration: Can optical displacement sensors be replaced by miniature accelerometers? | |
1MR:comp GmbH, Gelsenkirchen, Germany, 2MRI-STaR GmbH, Gelsenkirchen |
||
In this study the suitability of a miniature accelerometer for vibration measurements according to ISO/TS 10974 was investigated. Gradient-induced vibration of a titanium disc was measured both with an electric accelerometer and an optical displacement sensor and the obtained datasets were compared. Taking the characteristics of the setup into account, the results indicate that the used type of accelerometer is suitable to meet the specifications given in ISO/TS 10974. |
| 2633 | Parallel Transmission for Heating Reduction in Realistic Deep Brain Stimulation Lead Trajectories | |
1University of Toronto, Toronto, ON, Canada, 2Massachusetts General Hospital, MA, United States, 3US Food and Drug Administration, Silver Spring, MD, United States, 4Sunnybrook Health Sciences Centre, ON, Canada, 5Innovere Medical, ON, Canada |
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Implanted devices for deep brain stimulation (DBS) create a safety concern during MRI due to heating at exposed tip of the lead. Parallel transmit (pTx) can potentially reduce heating of the lead tip when radiofrequency (RF) inputs are selected by an appropriate numerical optimization method. To date, however, this method has not considered how the trajectory of DBS leads affects heat deposition. The present work investigates the optimized pTx method for realistic DBS lead trajectories estimated from intra-operative computed tomography (CT) scans of nine patients, with simulations indicating statistically significant reduction in heating at lead tips while maintaining reasonable B1+-field homogeneity. |
| 2634 | Bilateral Breast Phantoms for Fusion to Human Voxel Models for Specific Absorption Rate (SAR) Simulations | |
1Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 2School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, United States |
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To comply with US Food and Drug Administration (FDA) guidelines of MRI safety, we propose a method to simulate Specific Absorption Rate (SAR) information with bilateral breast phantoms seamlessly integrated to a human model. This modeling method can be used with various breast phantoms. The simulation results indicate breasts with high glandular contents are more susceptible to SAR safety concerns compared to breasts with low glandular content. |
| 2635 | Attenuation of RF-induced currents within neuro-stimulation leads using a helical conductor design | |
1Systems Engineering, Nuvectra Medical, Broomfield, CO, United States, 2R&D, Nuvectra Medical, Broomfield, CO, United States, 3R&D, Medical Technology Labs, La Mirada, CA, United States |
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RF currents will be induced within implanted neuro-stimulation leads when exposed to Magnetic Resonance Imaging (MRI) fields. Induced currents result in dissipative heating that manifests at the electrode/patient contact points. The ideal lead design will attenuate induced 64-MHz RF energy coming from the MRI while passing signals in the lower, intended neuro-stimulation frequency range. A Nuvectra™ SCS lead, having a helical conductor coiling design, is evaluated. Results of MRI phantom experiments demonstrate RF-induced power attenuation between -6.2 and -12.5 dB/meter when exposed to combined fields from 1.5 Tesla, 2.77 W/kg for minutes. |
| 2636 | Safety of intracranial EEG recordings at 1.5T MR: electromagnetic field simulation on a human body model | |
1Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, 2Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, United Kingdom, 3Laboratory of Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Laussanne (EPFL), Lausanne, Switzerland, 4Developmental Imaging and Biophysics Section, UCL Institute of Child Health, London, United Kingdom, 5Departments of Radiology, University of Lausanne and Geneva, Lausanne and Geneva, Switzerland |
||
Excessive tissue heating is one of the major concerns when performing MRI in patients with icEEG due to the RF interaction between the electrodes and head tissue. No electromagnetic field simulations has been performed on in-vivo iEEG-MR setup due to the subgridding limitations of the small dimensions of these electrodes relative to those of the human body. We showed the feasibility of full body EM-field simulations based on realistic icEEG-electrode design. The proposed FDTD method for simultaneous icEEG-MRI gives results that are in broad agreement with previous experimental observations while allowing for measurements of SAR/heating along the entire implant length. |
| 2637 | Magnetically Induced Torque Assessment per ASTM F2213 of Active Implantable Medical Device Lead Materials | |
1St. Jude Medical, Sylmar, CA, United States |
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This abstract presents magnetically induced torque measurements (per ASTM F2213) of materials commonly used in implantable leads. Implantable leads which are constructed solely from tested materials which pass the magnetically induced torque testing acceptance criteria of gravity torque, may not require magnetically induced torque testing per ASTM F2213 for MR conditionality with 3 T MR scanners. |
| 2638 | A Raspberry Pi® Based Portable Exposure Monitoring System for Magnetic Fields up to 7T. | |
1Otto Diels Institute for Organic Chemistry, Kiel University, Kiel, Germany, 2Molecular Imaging North Competence Center, University Medical Center Schleswig-Holstein, Kiel, Germany |
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ICNIRP recommends reference values for movements in magnetic fringe fields of MRI systems. Several probes have been presented using custom interfaces to record data. To open this field of research to a wider public a Raspberry Pi® based magnetic field monitoring system was built. A probe consisting of both three Hall sensors and induction coils was used. All channels were converted into frequency via voltage-to-frequency-converters. Data was stored internally via python. Measurements were performed on a 7T small-animal MRI at the hand of MR-workers. Reference values were exceeded at the hand. No transient effects like vertigo or nausea were noticed. |
| 2639 | Evaluation of 50mm vs. 100mm Landmark Step Size for Pacemaker RF MRI Safety Evaluation | |
1MRI Safety/Hardware Development, St. Jude Medical, Sylmar, CA, United States, 2MRI Safety/Hardware Development, St. Jude Medical, Sunnyvale, CA, United States |
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Pacemakers undergo evaluation per ISO/TS 10974 to determine MRI safety. In a 64 MHz 1.5T RF coil, a quarter wavelength for RF radiation within blood is approximately 130mm, suggesting simulations performed with z-dimensional landmark step size of 100mm might not sufficiently capture RF effects on power deposition at lead electrodes and voltage levels at the generator, requiring a 50mm step size instead. Through simulations using validated transfer functions, human body models, and MRI RF coil models, it is shown that the difference in results between 50mm and 100mm simulations may be incorporated into model uncertainty and 100mm simulations are sufficient. |
| 2640 | An investigation of skin/skin contact RF burns | |
1Toshiba Medical Research Institute, Mayfield Village, OH, United States |
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Third degree RF burns at skin/skin contact points have been reported. A thermal dose injury mechanism is widely assumed and thermal modeling results based on a well-documented calf burn report are presented. A hotspot ratio (Local:Whole Body SAR) of 86 results in various arbitrary CEM43 defined thresholds being exceeded after a few minutes of inadvertent skin/skin contact. The results support the hypothesis that skin/skin contact thermal injury burns are possible after several minutes of routine clinical scanning. |
| 2641 | A Method to Reduce Specific Absorption Rate for DBS Patients at 7 T MRI | |
1University of Ulsan, Ulsan, Korea, Republic of, 2Korea Basic Science Institute |
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The improtance of ultrahigh fields MRI has been rapidly increased due to its advantages in high resolution and signal-to-ratio. In this study, the SAR was analyzed in accordance with the conditions of insertion DBS and the electromagnetic field is controlled by multi-channel coil. Our reserch demonstrated the field control method using convex optimization from the fields data can be considered as a good strategy to drive the individual parameters of the RF coil for solving the inhomogeneity and SAR limitations, and it is safer for patients. |
| 2642 | Clinically Relevant Gradient and RF Field Exposure Levels for General Neuro MRI Protocols at 3.0 T | |
1Department of Physics and Astronomy, Western University, London, ON, Canada |
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Maximum fields for MRI systems pose overly restrictive guidelines for MR compatible device development. Logging of gradient strengths on a Siemens Prisma 3T MRI showed that during clinically relevant neuro scans, peak gradient strength reached 63.97 ± 0.05 mT/m, lower than the system maximum of 80 mT/m. In addition, peak slew rate during this protocol was measured to be 183.9 ± 0.2 T/m/s, compared to the system maximum of 200 T/m/s. This allows more flexibility for MR compatible device manufacturers due to the large discrepancy between the system maximum, and the practical maximums that the system reaches. |
| 2643 | Resolving Local SAR In Vitro from RF-Field Induced Heating of a 5.0 cm Long Titanium Rod at 64 MHz and 128 MHz | |
1Department of Physics and Astronomy, Western University, London, ON, Canada |
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A methodology is developed relating the RF-induced temperature rise for an elongated conductive 5.0 cm long titanium reference rod to the local SAR produced by the incident electric field in the rods absence. Local SAR values at various spatial probing distributions in a gel filled phantom torso were systematically resolved and assessed at 64 MHz and 128 MHz using two different RF birdcage coils. A calibrated commercial E-field RMS probe and conventional standardized 10.0 cm long titanium rod were both used to validate the approach, showing good agreement. The 5.0 cm long rod shows promise as an additional approach for experimentally determining local SAR. |
| 2644 | Numerical Simulation of Specific Absorption Rate (SAR) Induced in the Head as a Function of EEG Lead Conductivity during 256-channel dEEG/fMRI at 3T. | |
1Harvard Medical School, Boston, MA, United States, 2Massachusetts General Hospital, Boston, MA, United States, 3Mechanical Engineering, University of Maryland, MD, United States, 4Electrical Geodesics Inc., OR, United States |
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This study presents the numerical quantification of the relationship between the EEG lead conductivity and SAR induced in the head in EEG-fMRI at 3T and using a 256-channel dense array sensor net. SAR induced in the head normalized by the gold standard of no sensor net was an S-curve function of the EEG lead conductivity in the range 1S/m - 5.8.107 S/m, plateauing at 1 for lead conductivities below 10 S/m. |
| 2645 | Comparison of High pass and Low pass Radio-Frequency coils in 1.5 T MRI safety assessments of Active Implantable Medical Devices | |
1St. Jude Medical, Sylmar, CA, United States |
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Active Implantable Medical Device (AIMD) safety assessments in MRI per ISO/TS 10974 may include computer simulations to evaluate radio-frequency (RF) induced heating of tissue and RF induced voltage at the device. It is not known if the differences in assessments between High-Pass (HP) and Low-Pass (LP) RF coils can be ignored. In this work, electric-fields and AIMD related RF induced heating and voltage results from HP and LP coils were compared. It was determined that there is a significant difference in safety assessment results between HP and LP coils (maximum symmetric mean absolute percentage error 50.21 ± 0.68%). |
| 2646 | Comparison of Pacemaker Lead Tip Heating at 1.5 T and 3T | |
1Department of Bioengineering, University of California, Los Angeles, CA, United States, 2Department of Radiological Sciences, University of California, Los Angeles, CA, United States |
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Imaging patients with pacemakers at magnetic fields higher than 1.5T is widely contraindicated due to safety concerns. Since SAR increases with B₀² it is expected that lead tip heating (LTH) may increase substantially. Recent studies, however, provide evidence that contradicts this belief. Electromagnetic damping can occur in highly conductive materials at high field strengths and may result in lower LTH. Our objective was to compare LTH at 1.5T and 3T for five pacemakers with realistic implant configuration in the ASTM torso phantom. The results obtained showed that heating at 3T was not greater than 1.5T, which supports the argument that electromagnetic damping can result in lower LTH at higher field strengths. |
| 2647 | The Effect of Patient Orientation on Pacemaker Lead-Tip Heating at 1.5T | |
1Department of Bioengineering, University of California, Los Angeles, CA, United States, 2Department of Radiological Sciences, University of California, Los Angeles, CA, United States |
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Patients with pacemakers or implantable cardioverter defibrillators (ICDs) may require an MRI exam of any body part. Clinical guidelines indicate that patient orientation in the scanner depends only on the body part under examination. Lead tip heating (LTH) is also a function of patient orientation. In this study our objective was to compare LTH for head-first and feet-first orientations for five pacemakers with realistic implant configuration in the ASTM torso phantom. Our results suggest that depending on the anatomical region examined, proper patient orientation in the MRI scanner can reduce LTH. |
| 2648 | On the SAR load of typical head protocols at 7T | |
1Erwin L. Hahn Institute for MRI, University Duisburg-Essen, Essen, Germany, 2Clinic of Pediatrics I, Neonatology, University Hospital Essen, Essen, Germany, 3Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Friedrich Schiller University Jena, Jena, Germany, 4Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 5High Field and Hybrid MR Imaging, University Hospital Essen, Essen, Germany |
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In this retrospective study, log files of the RF safety watchdog system were evaluated from 30 head exams performed at 7T in conjunction with the widely available 32-channel Nova Medical head coil. Head local SAR as reported by the PALI and the start/end times of each sequence were compared for eight different sequence types. This study aimed at providing insights into the expected RF exposure in UHF neurological protocols and may become useful in simulations to study realistic exposure scenarios, as well as to determine which sequences may be acceptable if a SAR reduction is required for a 7T exam. |
| 2649 | Static Magnetic Field (B0) Gradient Evaluation of a Compact 3T MR Scanner | |
1Radiology, Mayo Clinic, Rochester, MN, United States, 2GE Global Research, Niskayuna, NY, United States, 3GE Global Research |
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The strength of the static magnetic field produced by a MR system varies with the distance from the scanner. This generates a magnetic field spatial gradient (SG) which produces an attractive translational force on ferromagnetic objects that approach the system. Because the SG has bearing on patient safety related to implanted medical device, it is essential to understand the field distribution of novel magnets, since each design has its own unique SG pattern. We performed on-site evaluation of the magnetic field SG for a novel high-performance compact 3T MR scanner to ensure patient safety during the subsequent clinical trial. |
| 2650 | Dependence of RF-induced heating pattern during MRI of a single wire on its mode of entry in a dielectric medium | |
1Imaging Institute, Cleveland Clinic, Cleveland, OH, United States, 2Physics, Case Western Reserve University, Cleveland, OH, United States |
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RF-induced heating of stereo encephalography (SEEG) electrodes during MRI scans could be of concern. Since the direction of entry of SEEG electrodes into brain can vary, heating of the tip of a single insulated copper wire (with bare tip) entering into a gel filled ASTM phantom axially (along the Z axis) and laterally (along the X axis) were measured as a function of the wire length. In this simple model of multi-wire multi-contact SEEG system, the resonating lengths (length with maximum heating) of the 2 configurations were same, while the lateral entry mode produced more heating. |
| 2651 | Validation of RF-induced temperature increase in a phantom: comparison of numerical simulations, MR thermometry and measurements from temperature sensors. | |
1Laboratory for Cognitive Brain Mapping, RIKEN Brain Science Institute, Saitama, Japan, 2Research Resources Center, RIKEN Brain Science Institute, Saitama, Japan |
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In this study, we compared the temperature increase calculated by the simulations and measured by the MR-thermometry in a phantom with those measured by the optical temperature sensors, with good agreement between the methods. To ensure safety, IEC guidelines require simulations of SAR along with validation in phantoms. While it is likely impossible to simulate every possible pulse shape and phase combination in a pTx system with a large number of transmit channels, the results we present here suggest that simulations plus MR-thermometry could provide the verification currently lacking in pTx studies. |
| 2652 | The encoder as leading part of detecting torque on implants for a fully automated test method in accordance to ASTM F 2213 standard to improve MR-Safety | |
1X-Ray & Molecular Imaging Lab, OTH Amberg-Weiden, Weiden, Germany |
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Due to magnetically induced torque, strong magnetic fields cause different effects on medical devices like implants. In accordance to that, this study should investigate by the help of a rotary encoder, if a rotary movement can be acquired to the ASTM standard. The used rotary encoder is specified with a high angular resolution, which enables detailed rotating motion detection, and its MR compatibility. |
| 2653 | A Dedicated Measurement Probe for Quantitative Common Mode Measurements and Balun Efficiency. | |
1Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States |
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A method to measure common mode voltages and balun efficiency is described. Common mode voltages were measured with a novel common mode measurement probe and oscilloscope along a coaxial cable of a loaded loop coil which was excited with a network analyzer at 127.74MHz. The common mode measurements were performed on the loop coil without a balun and compared to the same loop coil with a balun to evaluate the common mode attenuation of the balun. |
| Exhibition Hall | Wednesday 16:15 - 18:15 |
| 2654 | A high density 24 channel array coil extendable to 48 channels for human cortical MRI at 7T. | |
1University of California, Berkeley, CA, United States, 2University of California, San Francisco, CA, United States, 3Virtumed, LLC, Minneapolis, MN, United States, 4A. A. Martinos Center for Biomedical Imaging, Boston, MA, United States, 5Advanced MRI Technologies, LLC, Sebastopol, CA, United States |
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Coil arrays using smaller loop sizes allow increased signal close to the coil array. Such coil arrays with a large number of channels allow increased SNR across a large area of cortex, and accelerated imaging comparable to commercially available high-channel coils, with particularly good performance close to the coil array. These gains in SNR allow high-resolution (0.5mm isotropic) EPI |
| 2655 | Towards a Flexible Transceiver Array for 7 T Cardiac MRI: Evaluation of Decoupling Ring Effects | |
1Division MR Physics, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, 2IR4M (Imagerie par Résonance Magnétique Médicale et Multi-Modalités), Univ. Paris-Sud, CNRS, Université Paris-Saclay, Orsay, France |
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In view of building a flexible 7T 2D coil array for cardiac MRI at 7 T, transmission line resonators (TLRs) with and without decoupling ring are investigated. Using 3D EM simulation and MR measurements for single elements, it could be shown that the presence of the decoupling ring does not perturb significantly the $$$B_1^+/\sqrt{P_{input}}$$$ distribution of the TLR. 3D gradient echo images for both TLRs with and without decoupling rings have been acquired. No significant degradation in the image quality due to the presence of the decoupling ring was observed. |
| 2656 | A Sixteen-Channel Array Coil for Carbon-13 Spectroscopy of the Breast at 7T | |
1Biomedical Engineering, Texas A&M University, College Station, TX, United States, 2Electrical and Computer Engineering, Texas A&M University, College Station, TX, United States, 3Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 4Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 5Philips Medical Systems, Cleveland, OH, United States, 6Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States |
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Biomarkers detectable by carbon-13 NMR spectroscopy have known correlations with breast cancer characterization, but in vivo 13C spectroscopy has been limited by low SNR. To counteract this, a 16-element receive coil and isolating preamplifier box was constructed for carbon-13 spectroscopy of the breast at 7 Tesla. The array was characterized on the bench and showed good results in terms of ease of tuning, low element-to-element coupling and Q values. Scanner testing using the coil was preliminary but showed successful 1H and 13C transmission and that array elements were individually able to acquire spectra. |
| 2657 | A Modular, Scaleable, and Customizable Phased Array Structure Suitable for Ultra-High Channel Phased Arrays | |
1Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 2Clinical Engineering, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States |
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A novel three-layer frame was developed to enable scalable phased-array coils. The geometry of the three-layer frame allows a single 12-element tile to dock with up to four identical tiles. When adjacent tiles are docked, the overlap of coils in adjacent tiles is identical to the coil overlap within a tile. Two phased-arrays setups using 12-element tiles and integrated balun coil technology were constructed. The first contained two separate tiles and the second had two interconnected tiles. The phased-array coils were evaluated with phantom imaging experiments and with multiple in-vivo experiments. |
| 2658 | Optimal array configuration for cerebral cortex MRI at 7T: six center-fed dipoles with two loops RF coil array | |
1CIBM - LIFMET, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2Department of Radiology, University of Geneva, Geneva, Switzerland, 3Department of Radiology, University of Lausanne, Lausanne, Switzerland, 4CIBM-AIT, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland |
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Searching for optimal RF coil array for whole-brain MR applications, central-fed dipole was compared with fractionated dipole in a single and RF coil array configurations with combination of loop coils in measurements and electromagnetic field simulations in terms of B1+ transmit efficiency, field uniformity, SAR and mutual coupling in an array. High transmit field performances were shown over the cerebral cortex by using phase-only shimming with six center-fed dipoles with two loops RF coil array on experimentally measured B1+-maps and anatomical MR images. |
| 2659 | Structure Adjustment of Surface Dipole Antenna Elements for Body Imaging at 7 Tesla MRI | |
1Department of Biomicrosystem Technology, Korea University, Seoul, Korea, Republic of, 2Department of Electronics and Information Technology, Korea University, Seoul, Korea, Republic of, 3Korea Basic Science Institute, Cheongju, Chungcheongbuk-do, Korea, Republic of, 4Research Institute for Advanced Industrial Technology, Korea University, Sejong City, Korea, Republic of, 5ICT Convergence Technology for Health & Safety, Korea University, Sejong City, Korea, Republic of |
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In ultra-high-field magnetic resonance imaging (UHF-MRI), body imaging suffers from B1 inhomogeneity due to relatively short wavelength. A range of new radio frequency (RF) coil designs has been proposed to overcome this problem. As previously reported, dipole antenna had been proposed to address this B1+ inhomogeneity problem for body imaging. In this paper, structural adjustment of dipole antenna has been tried for parallel transmission to improve overall B1+ homogeneity. Surface dipole antennas with several structures are tried and compared with our top-hat dipole antenna array reported previously. Also, static RF shimming was employed to evaluate the B1 uniformity. |
| 2660 | An adjustable 8-channel receive coil for population studies of marmosets | |
1Centre for Functional and Metabolic Mapping, The University of Western Ontario, London, ON, Canada |
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An eight-channel RF coil was developed for imaging the common marmoset at 9.4T. The coil was adjustable in width to accommodate different head sizes while maintaining high SNR, thereby facilitating the study of larger cohorts of animals. Tuning and matching of the coil did not require adjustment over the range of potential head sizes. EPI time series were acquired, showing minimal geometric distortion with a two-fold reduction factor. A two-fold reduction factor could be achieved in both the left-right and anterior-posterior directions. |
| 2661 | Fifteen-channel receive coil for high acceleration rates in UHF marmoset imaging | |
1Centre for Functional and Metabolic Mapping, The University of Western Ontario, London, ON, Canada |
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A 15-channel receive coil, in conjunction with a 2-channel transmit coil, was developed for imaging the common marmoset at 9.4T. The high channel count produced low geometry factors while accelerating in EPI acquisitions, thereby reducing geometric distortions with minimal impact on the SNR. This demonstrates the utility and feasibility of employing higher channel counts for functional imaging of the marmoset. |
| 2662 | A 10-element receive-only RF coil array for imaging the brain of awake marmosets | |
1Department of Biomedical Engineering, Texas A&M University, College Station, TX, United States, 2Cerebral Microcirculation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States |
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A 10-element head RF coil array was developed for imaging the brain of awake marmosets. A soccer ball design was used to improve whole brain coverage and parallel imaging acceleration when compared to our previous designs. Coil clip and PLA cement were introduced to help place the small coil elements on surfaces of irregular shape and optimize geometric decoupling. The matching network provided independent adjustments of tuning, matching, active detune and preamp decoupling, greatly simplifying the construction of coil arrays in space-limited applications. Molded-in foam padding was also introduced to provide additional comfort during awake marmoset imaging. |
| 2663 | Ladder and Overlapped Phased Array Coil Comparison for Neck Imaging at 3 Tesla | |
1Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States |
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A ladder and overlapped phased array coils were constructed with the same number of channels and overall dimensions to see how much of a SNR performance difference there was between the two coil construction techniques. The results show that between 2 and 12 cm within a cylindrical phantom the difference between SNR was less than 3%. With negligible performance difference the ladder array can be a viable alternative to overlapped arrays if a simpler coil construction process is desired. |
| 2664 | Quadrature Head Coil for Brain Imaging at 6.5 mT | |
1Department of Radiology, MGH/AA Martinos Center for Biomedical Imaging, Boston, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3Department of Physics, Harvard University, Cambridge, MA, United States |
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Highly-resolved proton imaging is challenging in the millitesla regime. With the aim of enhancing our previous single-channel spiral head coil for operation at 276 kHz, a quadrature head coil was designed, comprised of 2 layers (inner and outer) producing orthogonal B1 fields. Images acquired with the new quadrature coil had the same signal magnitude when compared to the single-channel coil. However, the expected √2-factor signal enhancement in combined SNR was not fully realized due to a 30% higher noise floor observed in one quadrature. Improvements in gradient amplifier filtering will significantly improve the SNR. |
| 2665 | Dual-Tuned RF Coil system for Parallel Imaging of Human Lungs Using Perfluorinated Gases | |
1ScanMed, LLC, Omaha, NE, United States, 2Duke University, Durham, NC, United States |
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To create a dual-tuned (1H & 19F) receive-only surface coil array for pulmonary functional imaging. This satisfies an unmet clinical need because there is currently no widely accessible 3D measure of regional lung function. As a result, the current standard of care for diagnosis and evaluation of lung disease relies nearly exclusively on global measures such as spirometry. The technical significance of this proposal is that the implementation of parallel imaging for 19F MRI would provide a means to shorten breath hold times with marginal SNR impact as well as facilitate the development of real time free breathing image acquisitions. |
| 2666 | Ultra-high-field CAIPIRINHA modulated parallel transmit excitation for homogenous image reconstruction without RF shimming | |
1Diagnostic Imaging, MR, Siemens Healthcare Ltd, Frimley, United Kingdom, 2Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom |
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Ultra-high-field (UHF) provides higher SNR than conventional, clinically available field strengths. However, UHF suffers from heterogeneous transmit B1+ fields. At 7 T, the shortened transmit radio-frequency (RF) wavelengths have a similar value to the dimensions of the human head/thorax which may result in signal cancellation and local signal dropouts. In this paper, we propose a novel imaging scheme based on simultaneous excitation with all transmit channels. Controlled aliasing is used to encode each transmit channel independently which we term Tx-CAIPIRINHA. Tx-CAIPIRINHA has been demonstrated in-vivo. The concept uses the linear superposition of B1+ fields via the excitation flip angle which only holds true in the low flip angle regime. When normalizing to transmit efficiency, Tx-CAIPIRINHA achieved a marginally higher SNR than B1+ shimming, demonstrating the constructive combination of transmit sensitives throughout the image. |
| 2667 | Towards Routine Body Imaging at 7T Using a Hybrid Dipole and Birdcage Coil Array | |
1Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, United States, 2Center for Advanced Imaging Innovation and Research (CAI2R), NYU School of Medicine, New York, NY, United States |
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Body imaging at 7T is challenging due to wavelength effects, a low sensitivity in deep tissue1, and a large variation in body sizes across the patient population. A common approach is to use close fitting coils or dipoles2,3,4, which exhibit a high transmit and receive sensitivity and are fairly load independent, but lack the easy handling necessary for routine clinical use. We aim to construct an RF coil array for general purpose body imaging for routine use that is robust, easy, and safe to handle, while retaining adequate sensitivity in the deeper regions. Given these boundary conditions, we settled on a stand-off design5 with an RF shield. Thus, consciously sacrificing some sensitivity to improve handling and safety. After extensive optimization we converged to an optimal coil array consisting of a transceive dipole array complemented with a birdcage array for reception only. The array was completed and a sensitivity analysis with respect to body sizes was performed. |
| 2668 | An RF birdcage coil designed for an insert gradient coil dedicated to short-T2 MRI | |
1Institute for Biomedical Engineering, ETH Zürich and University of Zurich, Zurich, Switzerland |
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Two major challenges for MRI of short-T2 tissues are creating large gradient strengths and avoiding signal contamination from hardware parts, in particular the RF coils. In this work, to enable short-T2 MRI with a dedicated insert gradient coil, an RF birdcage coil was designed with a) minimized background signal and b) optimized B1 field to prevent aliasing associated with the limited monotonic range of the gradient. |
| 2669 | Multiple-Mouse Magnetic Resonance Imaging with CryoProbes | |
1Mouse Imaging Centre, Hospital for Sick Children, Toronto, ON, Canada, 2Medical Biophysics, University of Toronto, Toronto, ON, Canada, 3Ontario Institute for Cancer Research, Toronto, ON, Canada |
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Multiple-mouse MRI was implemented on a 7-Tesla magnet with four Cryogen (liquid helium)-cooled radio frequency probes. The high signal-to-noise ratio offered by the probes enabled spatial resolutions of 60 μm isotropic in <2 hours, a significant improvement for in vivo anatomical imaging of the mouse brain. Several 3D pulse sequences including FLASH/MP2RAGE/RARE were implemented for multiple-mouse acquisition. Manganese-enhanced T1-weighted images were obtained at two different resolutions of 60 μm and 75 μm. Results demonstrate the combined benefits of cryogen-cooled coils and multiple-mouse MRI. |
| 2670 | An SNR Optimized Quadrature Reception Posterior Array for Prostate Imaging at 3 Tesla | |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany |
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Increasing signal-to-noise-ratio (SNR) in prostate MRI could facilitate the diagnosis and characterization of prostate cancers. In this work, we built a quadrature posterior surface array that aims to increase local SNR at the prostate. The coil was compared to 3 and 9 channels of the standard spine array using phantom measurements. Respectively, SNR gains of 12 and 9% were obtained using a realistic region-of-interest (ROI). Further work will be undertaken to translate the SNR gains to in-vivo prostate imaging at 3T. |
| 2671 | New design of flexible surface coil with variodes and remote detuning | |
1RF-R&D, Siemens (Shenzhen) Magnetic Resonance Ltd., Shenzhen, People's Republic of China, 2R&D, Siemens (Shenzhen) Magnetic Resonance Ltd., Shenzhen, People's Republic of China |
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New design of flexible surface coil was presented. Voltage-controlled variodes instead of trimmers are used for remote coil frequency adjustment; λ/4 impedance transforming circuit are used to enable remote detune, thus detune circuits with big rigid components are moved out from the antenna part. By doing this, the antenna is covered by soft foam seamlessly which improved the flexibility significantly. Design was tested on four-element arrays. Experiments on both phantom and invivo testing show good results with this design. |
| 2672 | Human Brain Imaging at 7T With On-coil Transceivers | |
1Advanced MRI Section, LFMI, NINDS, National Institutes of Health, Bethesda, MD, United States, 2Food and Drug Administration, Silver Spring, MD, United States |
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On-coil current-source switch-mode amplification presents high power efficiency, allows direct control of the transmit field (B1), and decoupling of elements through the amplifier output impedance. These are important advantages over conventional remote voltage-mode quasilinear amplification that should allow more efficient and safer implementation of a multi-channel transmit system. Following this approach, we present an optically controlled transceiver design that was used for initial safety assessment of the technology toward the implementation of a high channel-count pTx array for brain imaging at high-field. We acquired human brain images with this technology at 7T |
| 2673 | An adjustable field-of-view rung element for 7T transmit array coils using forced current excitation | |
1Electrical& Computer Engineering, Texas A&M University, College Station, TX, United States |
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This abstract reports a switchable coil element which uses “forced current excitation”. The coil consists of three aligned rungs, with a total length of 37 cm. Any one or more of three rungs can be easily selected to provide a variable length or position field-of-view. The forced current approach ensures equal current on the selected rungs to give a uniform field distribution along the length of the field-of-view. Bench measurements demonstrate the expected efficiency improvement when only a single rung is selected and the uniform field pattern. |
| 2674 | Optimization via Ultra-high Permittivity Materials of Pad Effects in Dielectric Shimming at 7 Tesla MRI | |
1Aix Marseille Univ, CNRS, Centrale Marseille, Institut Fresnel, Marseille, France, 2Centre Commun de Resources en Micro-ondes, Marseille, France, 3CEA-DAM Le Ripault, Monts F-37260, France, 4Siemens Healthineers, Saint Denis, France, 5CEA, DRF, i2BM, NeuroSpin, UNIRS, Paris-Saclay University, Gif-sur-Yvette, France |
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The influence of air fraction on the permittivity of BaTiO3 aqueous mixtures was assessed, with the aim of obtaining high permittivity mixtures. For extremely saturated mixtures (>50%v/v), the air fraction of the mixture plays a great role in determining εr, and by applying high pressure it is possible to go beyond the maximal value described in dielectric shimming literature. A BaTiO3 1cm-thick pad was manufactured (εr =470) and tested in a 7T MRI, as well as a conventional saturated pad (≈40%v/v, εr=200). Results show an overall signal improvement when using higher permittivity pads and the possibility to reduce pad-thickness. |
| Exhibition Hall | Wednesday 16:15 - 18:15 |
| 2675
|
Detailing and Enhancing Respiratory Motion Induced Myocardial B0 Field Dispersion at 7.0 T: Implications for Cardiac Imaging and Spectroscopy at Ultrahigh Magnetic Field Strengths | |
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine in the Helmholtz Association(MDC), Berlin, Germany, 2Physikalisch Technische Bundesanstalt (PTB), Berlin, Germany, 3Experimental 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, 4DZHK (German Centre for Cardiovascular Research), partner site Berlin, Berlin, Germany |
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Respiratory motion induced B0 field fluctuations, constitute a challenge for B0 sensitive CMR like spectroscopy. Accommodating CMRS in a single breath-hold is elusive if not prohibitive. Motion corrected approaches under free breathing were demonstrated to substantially improve CMRS. Yet, B0 field fluctuations over the respiratory cycle may compromise spectral resolution and data integrity. A compensation strategy like dynamically updated first order shims synchronized with the respiratory motion, offers the potential to enhance spectral quality and permits scan time shortening. This work details respiratory motion induced B0 fluctuations in the interventricular septum and examines the capability of linear shimming for compensation of myocardial B0 fluctuations. |
| 2676 | Unilateral Linear Halbach magnets for single sided magnetic resonance: generalized design framework and experimental validation | |
1Electrical Engineering & Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 2David H. Koch Institute For Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, United States, 3Harvard–MIT Program of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States, 4Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States |
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Single-sided NMR has the potential for broad utility, especially as a portable diagnostic for disorders in fluid regulation. These sensors require a remote, high field, uniform magnetic field to achieve sufficient sensitivity. We demonstrate a new magnet geometry, the Unilateral Linear Halbach, that combines design principles from sweet-spot and linear Halbach magnets to achieve this goal. Sensitivity analysis using finite element analysis produces a generalized framework for Unilateral Linear Halbach design. Experimental validation through the fabrication of a magnet assembly shows close agreement with the simulated magnetic field. Unilateral Linear Halbach magnets increase the sensitivity, portability, and versatility of single sided NMR. |
| 2677
|
A new human-scale fast field-cycling MRI system for clinical applications | |
1Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, United Kingdom |
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Fast-field cycling MRI is a novel technique that involves cycling the main magnetic field during image acquisition. By doing this, information on the magnetic field dependence of parameters such as the T1 relaxation time can be investigated and exploited as a new form of endogenous image contrast. In this abstract we present progress on a new human-scale fast field-cycling MRI system with a detection field of 0.2 T. |
| 2678 | Towards ultimate air-core magnetometer sensitivity for ultra-low field MRI: A design method | |
1Centre for Advanced Imaging, UQ, Brisbane, Australia |
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Superconducting quantum interference devices (SQUIDs) are highly sensitive magnetometers and they have found application in ultra-low field MRI. However, they require cryogenics and their noise performance is hindered by external noise sources and the strong fields employed in pre-polarised MRI experiments. Air-core magnetometers provide an attractive alternative, as they are highly sensitive, robust and relatively cheap to manufacture. Our goal is to provide of a method to optimise the sensitivity of these devices. In this work we propose an accurate numerical model and the use of a genetic algorithm to consider previously unexplored coil configurations. |
| 2679 | Preliminary Metamaterial Design and Fabrication for MRI at 3T | |
1Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China, 2Department of Radiology and Biomedical Imaging, University of California San Francisco, CA, USA, CA, United States, 3UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco, CA, USA, CA, United States |
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In this paper, we designed and fabricated a kind of metamaterial with 9×9 cells, which bent on phantom and inserted to a birdcage volume coil to investigate the performance for 3T MRI. The results of simulations and phantom experiments agreed with each other very well indicate that the proposed metamaterial is able to increase the B1+ fields in some region closed to the surface of phantom. This improvement of B1+ fields will benefit to 3T MRI targeted clinical applications. |
| 2680 | Dual-layered multi-channel B0 and RF coil setup for an improved shimming performance at 9.4 Tesla | |
1High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany, 2Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom, 3Biomedical Magnetic Resonance, University Hospital Tübingen, Tübingen, Germany |
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Multiple local shim coils can be used to improve the B0 homogeneity at ultra-high field. In this work, a dual-layered multi-channel B0 and RF coil setup is presented that allows a flexible design of the shim coil without influencing the RF performance. It is shown that a 16 channel B0 coil in combination with a standard 2nd order spherical harmonics (SH) shim system can achieve a higher degree of B0 homogeneity than a 3rd order SH shim system in the case of whole-brain shimming. |
| 2681 | An insert gradient for zero-echo-time imaging with 200 mT/m at full duty cycle | |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Philips GmbH Innovative Technologies, Hamburg, Germany, 3Philips AG, Zurich, Switzerland, 4Futura Composites BV, Heerhugowaard, Netherlands |
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Zero-echo-time (ZTE) techniques enable imaging of tissues with very short T2s, e.g. bone or myelin. Their performance directly scales with gradient strength G, which depends on the target T2 and spatial resolution. With present-day gradients the spatial resolution for T2s on the order of 100 μs is limited to several millimetres. To improve the resolution, considerably higher gradient strengths are required. As a further challenge of ZTE sequences, the strong gradients are applied with full duty cycle. The goal of this work was to develop a gradient coil that meets these challenges, offering very high amplitude at full duty cycle. |
| 2682 | Open-Source Acquisition-speed slice-by-slice controller for 32 coil B0 shimming. | |
1Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States, 2A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, 3Harvard Medical School, Boston, MA |
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Accurate B0 shimming with close-fitting coil arrays can improve brain imaging at 3T and 7T, but slice-optimizing the shimming during acquisition requires fast redistribution of dozens of multi-amp coil currents. Our open-source, low-cost ($80/channel) driver system can redistribute fifty amps to thirty-two coils in milliseconds, with milliamp accuracy. The system uses an easily reprogrammed microcontroller, optical fiber isolation, and thirty-two current-feedback coil-drivers (described previously). When used to drive sixty-four slice-specific sets of currents in a novel 32-coil shim array, stretching in an EPI brain scan was substantially reduced, without introducing driver artifacts. |
| 2683 | Decoupling Controller Design for Real-time Feedback of B0 Shim Systems | |
1MPI for Biological Cybernetics, Tuebingen, Germany, 2IMPRS for Cognitive and Systems Neuroscience, Eberhard University of Tuebingen, Tuebingen, Germany, 3Institute of Physics, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany |
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Real-time B0 feedback has been shown to be beneficial for the controlling of B0 fluctuations. However, update rates that have been reported are slow (~100ms) and either use pre-emphasis to correct for the coupling and faster dynamics of the system or only use control the frequency We show that for faster update rates (±1ms) pre-emphasis (i.e. dynamic decoupling) is not required and that static decoupling can perform equally well or better. |
| 2684 | Dynamic B0 Shim Controller for Digital Pre-emphasis with Sub-millisecond Update Rate | |
1MPI for Biological Cybernetics, Tuebingen, Germany, 2IMPRS for Cognitive and Systems Neuroscience, Eberhard University of Tuebingen, Tuebingen, Germany, 3Institute of Physics, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany |
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High-order dynamic B0 shimming has been shown to improve the shim quality for multi-slice acquisition schemes. However, for gradient intensive sequences, eddy currents become a major problem and pre-emphasis is required. The pre-emphasis can be done flexibly with the use of digital filters as they can drive arbitrary-shaped waveforms and are scalable to a larger number of channels. In this work, we design and implement a system to perform dynamic B0 shimming with digital pre-emphasis with a very fast update rate. The setup is then tested for performing pre-emphasis on a 9.4T scanner. |
| 2685 | A scalable, MR compatible temperature measurement and control system | |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2University and ETH Zurich, Zurich, Switzerland |
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Tight temperature control of various devices is required to guarantee highly stable experimental conditions. E.g. B0 field shifts induced by heating of shim irons or gain changes induced in preamplifiers can be avoided by oven controlling the critical components of the device. Furthermore, a recently presented approach of active shimming with controlled magnetic materials requires tight temperature control of a large count of devices in parallel in the bore. For such applications, we present a 14 channel, low power, MR compatible temperature measurement and control system which can be parallelized for a scalable channel count. |
| 2686 | Minimum Current Ripple in the Gradient Array System by Applying Optimum-Phase Pulse-Width Modulation Pattern | |
1National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey |
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Phase-shifted Pulse Width Modulation (PWM) technique is implementable in stacked and parallel configuration of the H-bridge gradient amplifiers. However, in the gradient array systems where one stage amplifier is sufficient to drive each element, phase-shifted PWM is not feasible. In this work, similar technique is implemented by utilization of the coupling between the elements of the array and finding the optimized phases for each channel in order to have minimum current ripples. This method is tested for different gradient fields and high ripple reduction percentages achieved both in simulations and experiments. |
| 2687 | A Convertible Magnet Array and Solenoid Coil for a Portable Magnetic Resonance Imaging (MRI) System | |
1EPD, Singapore University of Technology and Design, Singapore, Singapore, 2Department of Surgery, National University of Singapore, Singapore, Singapore |
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A magnetic resonance imaging (MRI) for outdoor in-situ scanning is promising for biological studies. Here we propose a portable MRI system in which both the magnet array and the transceiver coil can be physically opened and closed. This is for imaging long objects in situ where cutting the object and fitting it into a bore for scanning is not an option. A convertible magnet array is designed where the force to open and to close the magnet array is minimized based on an analytical solution. Meanwhile, a convertible solenoid coil is proposed as an RF transceiver coil. |
| 2688 | An open source PXIe platform for MRI instrumentation development | |
1School of Engineering, Victoria University of Wellington, Wellington, New Zealand, 2School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand |
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To lower the entry barrier for MRI system development, an open source PXIe platform consisting of IP for peripheral boards, an associated linux device driver and example system controller and peripheral boards were developed. The design was capable of performing system controller initiated DMA transfers in both directions with a maximum block size of 8MB. The hardware design was greatly simplified by mounting FPGA modules from Avnet onto custom PXIe compatible carrier boards. The modules from Avnet contained a System on a Chip device from Xilinx consisting of a dual core ARM processor and FPGA fabric. |
| 2689 | Distributed receivers with hardware-accelerated signal processing: Synchronous acquisition of image data and k-space trajectories | |
1University and ETH Zurich, Zurich, Switzerland |
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The demand for higher image quality led to a significant increase in the number of parallel receive coils and to the addition of sensor systems such as magnetic field monitoring probes to MR systems, boosting the demand for many high quality receive channels. Furthermore, new methods increasingly require high acquisition duty cycles and bandwidths setting new requirements on data traffic and real-time capabilities. We present a flexible, scalable receiver system addressing those issues demonstrated on an example of concurrent imaging and field monitoring with real-time processing of synchronized streams of coil and trajectory data, as required by modern reconstruction algorithms. |
| 2690 | Sensitive Imaging of Vascular Walls with an Endo-esophageal Wireless Amplified NMR Detector (WAND) | |
1Radiology, Provincial People's Hospital, Guiyang, People's Republic of China, 2Radiology, Michigan State University, East Lansing, MI, United States |
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To improve the detection sensitivity of MRI, a Wireless Amplified NMR Detector (WAND) is developed to image surrounding vessels from inside the esophagus. This cylindrical detector is a double frequency resonator with a single metal wire that is self-connected by a pair of varactors. It can convert wirelessly provided pumping power into amplified MR signals. When the detector is inserted inside the esophagus, vessel walls of the vertebrate artery and basal artery can be identified with greatly improved clarity. This detector will be useful to characterize subtle lesions in inflamed vessels. |
| 2691 | Low IF Passive Mixer Topologies for Low Power MRI Front Ends | |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Electrical Engineering, Stanford University, Stanford, CA, United States, 3GE Healthcare, Aurora, OH, United States |
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As MRI array counts expand, there is growing interest in moving more of the receive electronics onto the array, the ultimate goal being wearable, and cordless arrays. This places severe constraints on the maximum feasible power consumption per channel. We explore low power front-end topologies employing passive mixers. If combined with low-power high resolution successive approximation ADCs or continuous time sigma delta ADCs, receive arrays at only 100mW per channel may be feasible. |
| 2692 | Wireless Clock Transfer for MRI Phase Correction | |
1Electrical Engineering, Stanford University, Stanford, CA, United States, 2Procyon Engineering, Stanford, CA, United States, 3Advanced Coils, GE Healthcare Inc, Aurora, OH, United States |
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One step in making wireless MRI possible is to sync the clocks at both the transmit side hardware that plays out the pulse, and the receive chain that processes the FID data. A discrepancy between the timing of the two clocks will lead to jitter that amounts to artifacts in the MRI image. In this work, we demonstrate a method to transfer a wireless clock without creating jitter artifacts in an MRI image. |
| 2693 | A chronic in situ coil system adapted for intracerebral stimulation during MRI in rats | |
1Psychiatry, McGill University, Montreal, QC, Canada, 2Biomedical Engineering, McGill University, Montreal, QC, Canada, 3Psychology, Northeastern University, Boston, MA, United States |
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We describe the fabrication and performance of a chronic in situ coil system designed to allow focal brain stimulation in awake rats while acquiring highly resolved MRI data. We developed a subcutaneously implantable receive-only surface radiofrequency coil to be fitted immediately adjacent to the rat skull surface during the cannulation procedure. SNR performance of the coil was superior to three commercially-available coils, in some instances by a factor of three. Widespread BOLD was observed in response to bicuculline and morphine microinfusions. This approach enables mapping the functional response to highly targeted stimuli such as microinfusions or optogenetics. |
| 2694 | High Power TRASE PIN Diode Control System | |
1Electrical and Computer Engineering, University of Alberta, Edmonton, AB, Canada, 2Medical Physics, Cross Cancer Institute, Edmonton, AB, Canada, 3Oncology, University of Alberta, Edmonton, AB, Canada |
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TRASE is a k-space encoding method for low cost MRI that replaces conventional imaging gradients with a switchable RF transmit array. TRASE echo train sequences require rapid switching between transmit elements to cycle through up to six different phase gradient encoding fields. In vivo image resolution is currently limited because long (~500μs) refocusing pulses render the echo train sequence vulnerable to T2 losses. Here we present a design for a high power PIN diode driver circuit capable of robust and rapid switching of short (~100μs) high power pulses for a 24cm coil. Results from 0.2T experiments are shown. |
| 2695 | The effect of Gaussian Filtering in ZTE based Attenuation Correction of PET/MR | |
1Department of Surgical Sciences, Uppsala University, Uppsala, Sweden, 2GE Applied Science Laboratory, GE Healthcare, Sweden |
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Zero-Echo Time (ZTE) has been proposed as an alternative attenuation method for PET-MR brain imaging. However, the filtering effects on these ZTE AC maps have not been explicitly discussed, in relation to effects on reconstructed and corrected images, and that is what we aim to develop in this study. |
| 2696 | A Simple Head-sized Phantom for Realistic System Characterization at 7T | |
1Leiden University Medical Center, Leiden, Netherlands |
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A simple head-sized phantom has been developed to produce realistic B1 and B0 features and electrical loading conditions, as a tool for the evaluation of MR techniques and RF validation in high field MR systems. |
| 2697 | Enhancement of signal intensity using a wireless coil for FT-EPR oximetry study, implanted in an animal body | |
1Radiation Biology Branch, National Cancer Institute, Bethesda, MD, United States, 2GenEpria Consulting Inc., Columbia, MD, 3National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States, 4Department of Radiology, Michigan State university, East Lansing, MI, United States |
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Improvement in sensitivity is required to detect the weak signals with Fourier transform Electron Paramagnetic Resonance (FT-EPR). In the proposed method, the signal from a wireless coil filled with sample was enhanced by using pumping coil in the regular EPR system. In this study, we achieved approximately 6-fold of improvement in signal intensity compared with conventional FT-EPR system under the simulated condition of animal body. We will also show the results of oximetry using the LiPc in, in vivo applications to measure tissue oxygenation. |
| Exhibition Hall | Wednesday 16:15 - 18:15 |
| 2698 | Control of an MRI-Guided Magnetically-Actuated Steerable Catheter System | |
1Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH, United States, 2Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 3Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH, United States, 4Radiology, University of Hospitals of Cleveland, Cleveland, United States |
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This paper presents a Jacobian-based inverse kinematics and open-loop control method for an MRI-guided magnetically-actuated steerable intravascular catheter system. The catheter is directly actuated by magnetic torques generated on a set of current-carrying micro-coils embedded on the catheter tip by the magnetic field of MRI scanner. The Jacobian matrix is derived from a three dimensional kinematic continuum model of the catheter deflection. The inverse kinematics are numerically computed by iteratively applying the inverse of the Jacobian matrix. Experimental evaluation compares a catheter prototype’s desired trajectory to the actual trajectory. |
| 2699 | Experimental study for efficient RF-penetration through electrically-floating PET insert for MRI systems | |
1National Institute of Radiological Sciences, Chiba, Japan, 2Radiology, Stanford University, CA, United States, 3Chiba University, Chiba, Japan |
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PET inserts for the existing MRI systems are showing great potential for widespread and affordable low-cost simultaneous PET/MR imaging that would otherwise improve the PET sensitivity due to the proximity of detectors to the imaging region. To avoid electromagnetic interference between PET and MRI components, PET detectors are enclosed in Faraday shield cages. A electrically floating PET insert enables us to use MRI built-in body RF coil instead of using separate custom designed RF coil with the PET insert. This study experimentally evaluates different PET geometries and different design factors for efficient RF penetration through the floating-PET insert. |
| 2700 | RF Power Considerations for Simultaneous Multi-Nuclear MRI/MRS | |
1Electrical & Computer Engineering, Texas A&M University, College Station, TX, United States |
||
There are many approaches to simultaneous multi-nuclear spectroscopy, but the simplest and potentially the most elegant involves sending all frequencies through a single broadband amplifier into a single-port, multi-tuned coil. This abstract examines a complication in this approach, that of early saturation of the amplifier due to the need to amplify two signals simultaneously. A simple solution, staggering the RF pulses a small amount to avoid the overlapping of their peaks, is shown to largely avoid the problem. |
| 2701 | A novel head coil system with integrated transmission source for accurate attenuation correction in PET/MR scans | |
1Division MR Physics - Center for Medical Physics and Biomedical Engineering, Medical Unversity of Vienna, Vienna, Austria, 2Center for Medical Physics and Biomedical Engineering, Medical Unversity of Vienna, Vienna, Austria |
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A 24 channel head and neck coil for PET/MR with an integrated moving radioactive source is presented to enable transmission measurements for accurate attenuation mapping. |
| 2702 | Evaluation of a metasurface resonator for in vivo imaging at 1.5T | |
1MediWiSe| Medical Wireless Sensing Ltd, London, United Kingdom, 2Department of Nanophotonics and Metamaterial, ITMO University, St. Petersburg, Russian Federation, 3Nonlinear Physics Center, Australian National University, Canberra, Australia, 4C.J. Gorter High Field Magnetic Resonance Center, Leiden University, Leiden, Netherlands |
||
We present in vivo results from a metasurface structure comprising an array of brass wires embedded in a high epsilon and low loss medium. The metasurface was used to scan humans in a 1.5T MRI scanner and demonstrated enhancement of the signal-to-noise ratio up to 200% in the area-of-interest close to the metasurface. |
| 2703 | Design of Self-Resonance Modes (SRM) of monolithic ultra-high dielectric constant (uHDC) materials and RF Coils for B1 field enhancement | |
1Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, PA, United States, 2Department of Engineering Sciences and Mechanics, The Pennsylvania State University, State College, PA, United States, 3Radiology Department, Center for Magnetic Resonance Research, MN, United States |
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Ultra-high dielectric constant (uHDC) materials were established as an effective B1 shimming and enhancement tool in MRI. A dielectric material operates at certain frequency range and enhances fields at an anticipated resonance frequency. We trimmed a rectangular dielectric block such that the fundamental frequency mode of the block resonated at 3 T, and compared it with a similarly sized non-resonant block. Both cases were coupled with a transmit receive surface coil resonant at 123.2 MHz. The effect of the surface coil area on the B1 field enhancement was explored to optimize the dielectric and coil configuration. |
| 2704 | Reducing the screening during transmission using non-linear properties of high sensitivity superconductor radiofrequency coils for magnetic resonance micro imaging | |
1Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, Palaiseau, France, 2Laboratoire d’Imagerie par Résonance Magnétique Médicale et Multi-Modalités (IR4M), UMR8081, CNRS, Université Paris-Sud, Université Paris Saclay, Orsay, France, 3Laboratoire des Solides Irradiés, CNRS UMR 7642 & CEA/DSM/IRAMIS, Ecole Polytechnique, Palaiseau, France, 4Aix-Marseille Univ, CNRS, CRMBM UMR 7339, Marseille, France |
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In MRI, high-temperature superconducting (HTS) radio frequency (RF) coils have been shown to greatly improve the signal-to-noise ratio. The nonlinear behavior of superconducting materials as a function of the emitted RF power is, nowadays, one of the principal technological obstacle limiting the use of these materials on a wider scale. It could be overcome by using HTS coil in reception mode only. Here we characterize these non-linear properties and use them to decouple the HTS coil during transmit mode. This preliminary study is a promising approach to use the highly sensitive HTS coils in reception mode only. |
| 2705 | Exploring New Possibilities in Array Design using Partially Orthogonal RF Resonators (Parti-Coils): A Numerical Simulation Study at 3 Tesla | |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany |
||
Partially orthogonal RF resonators (Parti-coils) is a novel concept in which RF coils are extended in an orthogonal direction. This increases overlap distance between elements. Therefore, coil density can be optimized. We show alternative geometrical coil configurations in array design using Parti-coils and compare them to an array of traditional planar coils using numerical simulations. Parti-coils enhanced the flexibility in array design, increased the overlap distance between coils by a maximum 3.2-fold, decreased next-nearest neighbor coupling by more than 6dB, showed up to 6.6% higher |B1-|acc. penetration depth, and a factor 1.05 increase of |B1-|acc. at a ROI. |
| 2706 | Modified FCE Transmit Coil for Bilateral Breast Imaging at 7T with Array Coil Inserts | |
1Electrical and Computer Engineering, Texas A&M University, College Station, TX, United States, 2Biomedical Engineering, Texas A&M University, Bryan, TX, United States, 3Univesity of Texas Southwestern Medical Center, 4Texas A&M University, TX, United States, 5Texas A&M University |
||
This work describes a forced-current-excitation (FCE) bilateral breast coil, modified for the insertion of a 32-channel receive array for 1H imaging and spectroscopy at 7T. A previous design of the bilateral quadrature volume coil employed RF shielding which prevented the insertion of a receive array with the associated hardware and cabling. The modified bilateral coil uses twinaxial cable for the FCE-enabling quarter-wave transmission lines, allowing balanced signal transmission and eliminating the need for the shields. The results include uniform bilateral excitation, an increase in efficiency as compared to the shielded coil, and successful installation of the 32-channel receive array. |
| 2707 | A 16 Element Bow-Tie Slot Array Coil for Parallel Transmit MRI/MRS | |
1Electrical and Computer Engineering, Texas A&M University, college station, TX, United States, 2Electrical and Computer Engineering, Texas A&M University |
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We report a volume coil consisting of 16 bowtie slot elements arranged in eight independent modules. The slot coils provide several interesting advantages over conventional elements. In particular they demonstrate a high degree of Intrinsic coupling between modules, making this array ideally suited for use in parallel transmit using conventional amplifiers. Additionally, all match and tune elements, baluns and feedlines are concealed between two ground planes, shielding the imaging volume from stray electric fields. Imaging results are shown at 4.7 Tesla demonstrating isolated patterns and a broad coverage in volume coil mode. |
| 2708 | In-Bore High Efficiency Current Driver | |
1Dept of Radiology, Case Western Reserve University, Cleveland, OH, United States |
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Recent work has shown the use of shim and gradient coil arrays for dynamic shimming and novel spatial encoding methods. These arrays require precise current source drivers with high power and bandwidth. Because of these demands, shim and gradient arrays are typically driven with amplifiers which are located outside the magnet bore due to constraints on power dissipation, radiofrequency interference (RFI), or magnetic materials. Here we present a highly efficient digitally-controlled switchmode current driver. We demonstrate that it is feasible to shield the RFI from the receive chain while avoiding ferrous materials and large heatsinks. |
| 2709 | A technique to compensate signal loss in an RF switch matrix system in MRI | |
1Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich, Juelich, Germany, 2School of Electrical and Electronics Engineering, Chung-Ang University, Seoul, Korea, Republic of, 3Faculty of Medicine, Department of Neurology, JARA, RWTH Aachen University, Aachen, Germany |
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MRI RF channels refer to the pathways of received signals and the availability of multiple channels allows one to access multi-channel array coils. To control the use of different coils, MRI usually utilises a crossbar-type switch matrix system that interactively connects the selected coil as an input and corresponding analogue-to-digital converters as an output. However, since the RF wavelength decreases with increasing B0, impedance in RF pathways varies in accordance with wavelength. This results in signal loss and in degraded image quality. In this study, we proposed an RF loss compensation technique for the switch matrix and verified its performance. |
| 2710 | Automated localization of 55Mn fiducial markers for coil array placement in hyperpolarized 13C MRI: dependence on number of acquired projections | |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States |
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Accurate RF coil localization is important for hyperpolarized 13C MRI. Fiducial markers can be constructed from 55Mn and localized using projection imaging. This study examines the minimum number of projections necessary to localize the markers subject to the known distances between markers. This would potentially allow marker localization to be automated as part of prescan. |
| 2711 | Improved Decoupling for 13C Coil Arrays Using Non-Conventional Matching and Preamplifier Impedance | |
1Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark, 2Department of Clinical Medicine, Aarhus University, Aarhus, Denmark |
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In this study, we describe a method to obtain improved preamplifier decoupling for receive-only coils. The method relies on the better decoupling obtained when coils are matched to an impedance higher than 50 Ω. Preamplifiers with inductive imaginary impedance and low real impedance, increases the effectiveness of the decoupling. A 2-channel 13C array of 50 mm loop coils show an increase of Q-factor of the coils from 247 to 365. The measured SNR, using two small phantoms, demonstrated a similar improvement. |
| 2712 | SWIFT imaging for hyperpolarized xenon in ultra-low field MRI | |
1Dept. of Electrical Engineering, Graduate school of Engineering, Kyoto University, Kyoto, Japan |
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ULF-MRI is one of the recent imaging techniques. Since
a polarization rate of hyperpolarized xenon is independent of B0, hyperpolarized
xenon is suitable for ULF-MRI. A xenon imaging using SWIFT has been proposed by
Nakamura et al. to reduce the decay caused by the xenon's diffusion. In this
study, we assess the effectiveness of the SWIFT pulse sequence for hyperpolarized
xenon imaging in ULF-MRI. The simulation results showed
that we could obtain the hyperpolarized xenon images with the SWIFT approach in
ULF-MRI and reconstructed images were improved by the oversampling in readout
direction and wide bandwidth. |
| 2713 | Magnetic and RF Shielding of a Novel Compact 6MeV Linac for MRI Guided Radiation Therapy System | |
1ViewRay Inc, Oakwood Village, OH, United States |
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We report on successful testing of a novel magnetic and RF shielding technology for a 6MeV Linac for MRI guided radiation therapy system. It allows complete decoupling of the Linac and its components from the MRI system. A low field region is created where the Linac can be operated without any problems. The system is compact and allows positioning of all magnetically and RF sensitive Linac components on a rotating Gantry and treat patients from any angle. |
| 2714 | Design and characterization of an RF shield for a 400 MHz birdcage coil in a retrofitted PET camera for preclinical PET-MRI | |
1Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 2MRI Clinical and Translational Research Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States, 3Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy, 4Laboratori Nazionali del Gran Sasso, Istituto Nazionale di Fisica Nucleare, Assergi, L'Aquila, Italy, 5Dipartimento di Scienze Fisiche e Chimiche, Istituto SPIN-CNR, Coppito, LAquila, Italy |
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PET-MRI imaging sets the stage for truly novel imaging approaches, but preclinical hybrid systems, characterized by ultra-high static magnetic field and small bore diameter, are still in the proof-of-concept stage. In this study, we developed an optimized RF coil/shield setup for an ultra-high field compatible prototype PET ring that can be retrofitted to conventional small-animal MRI systems. In particular an original shielding solution was designed and tested with the purpose of maximizing coil efficiency, usable space inside the detector, and PET sensitivity. |
| 2715 | Wrist coil for low field MRI | |
1Medical Imaging Research Cenre, Dayananda Sagar Institutions, Bangalore, India |
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Image Signal to Noise Ratio (SNR) and resolution are significant challenges in ultra-low field MRI. A single channel transmit coil and a 4-channel phased array was developed for wrist to operate at 9.5mT. The current work involves integration with the DDS module for verifying functionality. Future work is to develop phased array for head MRI. |
| 2716 | Flexible General-Purpose Embedded System for Real-time Feedback and Dynamic B0 Shimming | |
1MPI for Biological Cybernetics, Tuebingen, Germany, 2IMPRS for Cognitive and Systems Neuroscience, Eberhard University of Tuebingen, Tuebingen, Germany, 3Institute of Physics, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany |
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B0 shimming methods are becoming more sophisticated. Methods such as multi-coil shimming, dynamic B0 shimming with pre-emphasis and real-time feedback all require additional hardware to drive the shim coils. In this work, we present a novel general-purpose embedded platform for controlling any of the above mentioned shim systems. Control software can be developed on Linux, while low-level scripts are used for optimal control of hardware interfaces. |
| 2717 | Homomorphic determination of noise variance and denoising using a non-local means filter for assessing the accuracy of automated segmentation | |
1CorTechs Labs, San Diego, CA, United States, 2Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey |
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Automated segmentation algorithms have been used more and more frequently for research and clinical purposes. There are available software packages that can determine volumes of brain structures and lesions. While signal to noise ratio in volumetric images is one of the determinants in the accuracy of such software, the effect of noise |
| 2718 | Pushing sodium imaging into clinical use - A technical feasiblity study | |
1Computer Assisted Clinical Medicine,Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany |
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Sodium MRI keeps becoming more interesting for multiple studies and clinical applications due to its capability to provide information on tissue viability. This information would be highly valuable in the clinical routine.We analyze technical possibilities to allow pushing sodium MRI into clinical use. In particular, we investigate approaches for transmitting and receiving sodium and proton signals using the same hardware. One main target of these approaches is to be fully compatible with standard 3T MRI systems without decreasing significantly the performance of proton imaging. We prove the feasibility for such systems. Yet, some drawbacks have to be taken into account. |
| Exhibition Hall | Thursday 8:15 - 10:15 |
| 2719 | Simultaneous measurements of myocardium T1, T2 map, Cine and synthetic LGE using Inversion Recovery tiny golden angle radial balanced-SSFP within 6 second | |
1Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea, Republic of |
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In the cardiac MRI study, the quantification of T1, T2 relaxation time has become an important indication as well as the cine and the late gadolinium enhancement. In this work, we presented a novel method for simultaneous acquisition of T1, T2 map and Cine image of the myocardium based on the transient phase of inversion recovery balanced-SSFP imaging, and was proven potential both phantom and in vivo on a healthy volunteer. |
| 2720 | Accurate Myocardial T1-Mapping in Arrhythmia using Saturation-Recovery during Systole at 3T | |
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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In arrhythmic patients, ECG mis-triggering frequently leads to T1-quantification inaccuracy. In this study, a heart-rate independent saturation-recovery T1-mapping method was adapted for systolic imaging at 3T by performing magnetization saturation right after the systolic imaging window and prior to R-wave detection. Estimated T1- and ECV- values during systole were (1557±53ms/ 0.21±0.03) compared to (1585±58ms/0.21±0.03) at diastole. Our results show that SR T1-mapping might be an advantageous alternative to yield accurate T1- and ECV-values in patients with arrhythmia or reduced myocardial wall-thickness. |
| 2721 | Towards High Success Rate in vivo Cardiac DTI on a Clinical 3T Scanner: Considerations on Heart Rate, Body-to-Mass Index, and Free Breathing | |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Bioengineering, University of California Los Angeles, Los Angeles, CA, United States, 3Siemens Healthcare, Los Angeles, CA, United States |
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Clinical translation of cardiac diffusion tensor MRI has been challenging because of the sensitivity to bulk motion and thus, low success rates of scans. Current techniques require either high gradient systems (>40 mT/m) or excess breath holding ( >10 breath holds / slice) to acquire motion free cardiac DT-MRI. We propose a cardiac DT-MRI technique optimized for clinical translation and aimed at achieving high success rates in subjects with high and variable heart rate and high bold-to-mass index under free breathing conditions. Results in subjects with high BMI and variable HR yielded success rates > 90%. |
| 2722 | Multi-parametric cardiac MRI for T1 mapping and cine imaging using iterative model-based image reconstruction | |
1Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and 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, 4Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom |
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In cardiac MRI, different diagnostic parameters are obtained in separate scans, leading to long examination times. In this work, we present an iterative model-based reconstruction approach for continuously acquired data, which provides native T1 maps and functional cine images within a single breath hold. The continuous acquisition allows for T1 reconstruction for different cardiac phases. Evaluation in a phantom demonstrated accurate T1 values (R²>0.99) and insensitivity to heart rates, with T1 variations of less than 5% (50 to 90 bpm). In three healthy volunteers T1 maps were assessed for diastole and systole and cine images had a consistent dark-blood contrast. |
| 2723 | Non-ECG, Free-breathing Joint T1-T2 Mapping in the Myocardium with CMR Multitasking | |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 3Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States |
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Myocardial tissue characterization via quantitative T1 and T2 mapping is typically accomplished using ECG-triggering and breath-holding. Here we describe a novel method for non-ECG, free-breathing joint T1-T2 mapping using the cardiovascular low-rank tensor imaging framework for CMR multitasking. This method achieves joint T1-T2 mapping in the myocardium at multiple cardiac and respiratory phases within 1.5 min for one slice. Measurements were within the range reported in the literature, and were repeatable to 3.9% for T1 and 6.1% for T2. |
| 2724 | End-systolic myocardial T1 mapping using a spoiled steady-state approach: Towards reducing the confounding effect of intra-myocardial blood on native T1 | |
1Biomedical Imaging Research Institute, Dept. of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States |
||
Recent results in myocardial tissue characterization using cardiac MRI have shown that native myocardial T1 values are confounded by intra-myocardial water content, mainly driven by |
| 2725 | Left Ventricle Remodeling in Bicuspid Aortic Valve Evaluated by ECG, Echocardiography, and Cardiovascular Magnetic Resonance | |
1Department of Radiology, Northwestern University, Chicago, IL, United States, 2Department of Radiology, Yale New Haven Health Bridgeport Hospital, Bridgeport, CT, United States, 3Department of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, United States |
||
The relationship between ECG characteristics, left ventricular (LV) diastolic function by echocardiography and Gadolinium extracellular volume fraction (ECV) in bicuspid aortic valve (BAV) are unknown. We aimed to test the hypothesis that BAV has an association with LV hypertrophy, myocardial fibrosis, and diastolic dysfunction. Cardiac magnetic resonance, ECG, and echocardiography were performed in 80 patients with BAV and 34 patients with trileaflet aortic valve (TAV). ECV was significantly higher in BAV than TAV. ECV, Sokolow-Lyon voltage, Cornell product, and e’ demonstrated significant relationships with LV end-diastolic volume index. ECV can be a useful predictor of LV remodeling in BAV. |
| 2726 | Simultaneous T1 and T2 mapping of the myocardium in normal volunteers using Cardiac MR Fingerprinting | |
1Radiology, University Hospitals Cleveland Medical Center / CWRU, Cleveland, OH, United States, 2Biomedical Engineering, Case Western Reserve University, 3Case Western Reserve University, 4Case Western Reserve University School of Medicine, 5Radiology, Case Western Reserve University, 6Radiology, University Hospitals Cleveland Medical Center, Cleveland, OH, United States, 7Epidemiology and Biostatistics, Case Western Reserve University School of Medicine, 8Radiology and Biomedical Engineering, University Hospitals Cleveland Medical Center / CWRU, Cleveland, OH, United States, 9Biomedical Engineering, University Hospitals Cleveland Medical Center / CWRU, Cleveland, OH, United States |
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This study reports normative cardiac T1 and T2 values generated in a single cardiac MRF scan in a cohort of normal volunteers. These values were compared against MOLLI (for T1) and bSSFP (for T2). Our results show that cardiac relaxometry values obtained with MRF at 1.5 T are comparable to values previously reported in the literature and those obtained using MOLLI and bSSFP. |
| 2727 | Myocardial fibrosis is a predictor of adverse outcomes in thalassemia intermedia patients | |
1Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy, 2"ARNAS" Civico, Di Cristina Benfratelli, Palermo, Italy, 3Presidio Ospedaliero “Giovanni Paolo II”, Lamezia Terme, Italy, 4Presidio Ospedaliero "Giovanni Paolo II" - Distretto AG2 di Sciacca, Sciacca, Italy, 5Azienda Ospedaliera Civile - O.M.P.A. Ragusa, Ragusa, Italy |
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Myocardial fibrosis detected by LGE has been confirmed as an independent predictor of CV complications in thalassemia intermedia patients. Our finding is consistent with a growing evidence that LGE has a strong prognostic impact in thalassemic patients, warranting a close clinical and instrumental follow-up. |
| 2728 | Association between cardiac iron clereance and hepatic siderosis by T2* MRI in thalassemia major patients | |
1CMR Unit, Fondazione 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, 4Ospedale Sandro Pertini, Roma, Italy, 5Policlinico S. Orsola "L. e A. Seragnoli", Bologna, Italy, 6Policlinico Umberto 1, Roma, Italy |
||
We evaluated in thalassemia major (TM) if the cardiac efficacy of the three iron chelators (Desferrioxamine, Deferiprone, and Deferasirox) was influenced by hepatic iron levels over a follow up of 18 months. In patients treated with Deferasirox and Deferiprone percentage changes in cardiac R2* over 18 months were associated with final liver iron concentration (LIC) and percentage LIC changes. In no chelation group percentage changes in cardiac R2* were influenced by initial LIC or initial cardiac R2*. |
| 2729 | The prognostic role of hypertrabeculation by cardiac magnetic resonance in thalassemia intermedia patients | |
1Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy, 2Università degli Studi di Palermo, Policlinico "Paolo Giaccone", Palermo, Italy |
||
We prospectively assessed whether the Piga’s criterion for left ventricle non-compaction (LVNC) (NC/C ratio threshold of >2.5) had a prognostic role for adverse cardiovascular outcomes in thalassemia intermedia patients. We found out that patients with Piga’s positive criterion had a significant higher risk of developing cardiac complications globally considered and arrhythmias. |
| 2730 | Gender-based optimization of cardiac follow up in thalassemia major patients | |
1Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy, 2CMR Unit, Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy, 3"ARNAS" Civico, Di Cristina Benfratelli, Palermo, Italy, 4Azienda Ospedaliera "Garibaldi" Presidio Ospedaliero Nesima, Catania, Italy, 5Fondazione di Ricerca e Cura "Giovanni Paolo II", Campobasso, Italy, 6Presidio Ospedaliero ASL 5, Crotone, Italy, 7Ospedale “Giovanni Paolo II”, Olbia, Italy |
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Females seem to tolerate iron toxicity better, possibly as an effect of reduced sensitivity to chronic oxidative stress. Based on our data about the significantly different risk in developing cardiac complications, in females older than 20 years the FU may be performed every 24 months, thus optimizing health care costs. |
| 2731 | Improved Myocardial T1 mapping using a Novel Motion-Insensitive Reconstruction | |
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 2MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom |
||
Myocardial T1 mapping sequences are commonly performed under breath-hold conditions. However, motion between T1-weighted images can be observed in ~50% of acquisitions. Image registration algorithms can be used for motion correction but are not available on all scanners, can occasionally fail and remain challenging using low contrast sequences such as saturation-based T1 mapping techniques. In this study we sought to develop and evaluate a novel motion-insensitive T1 mapping reconstruction approach which automatically discards misaligned/artefact T1-weighted images. |
| 2732 | Free Breathing Myocardial MOLLI T1 Mapping using Real-time Slice Tracking and Non-Rigid Image Registration | |
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 2MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom |
||
The modified Look Locker (MOLLI) sequence is the most widely used myocardial T1 mapping approach. In this 2D sequence, several T1-weighted images are acquired within a breath hold and used to create a T1 map. However, some patients are unable to sustain stable breath-holds which generates 3D motion between the T1-weighted images. While image registration can potentially be used to correct for in-plane motion, through-plane motion cannot be corrected and may introduce bias in T1 estimates. In this study, we sought to develop and assess a free breathing MOLLI sequence with real-time slice tracking and non-rigid image registration to reduce in-plane and through-plane motion effects. |
| 2733 | Off-resonance correction in myocardial T1-mapping using Bloch simulations of the MOLLI sequence | |
1Fondazione Toscana "G. Monasterio", Massa, Italy, 2Fondazione Toscana "G. Monasterio", Pisa, Italy, 3CNR Institute of Clinical Physiology, Pisa |
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Myocardial T1 mapping using MOLLI is influenced by off-resonance effects that lead to underestimation of T1. In this study a method for the correction of the off-resonance influence on T1 mapping, based on the Bloch simulations of the MOLLI sequence, is proposed. In vivo results on a healthy population (N=67) showed that the regional variation of T1 is highly correlated with the distribution of the off-resonance. The proposed method effectively reduced the artifactual T1 underestimation due to off-resonance, especially in myocardial segments that exhibited elevated B0 inhomogeneities. |
| 2734 | Quasi black blood T1-mapping using slice-selective TRASSI for improved visualization of the myocardium | |
1Department of Internal Medicine I - Cardiology, University Hospital Würzburg, Würzburg, Germany, 2Comprehensive Heart Failure Center (CHFC), University Hospital Würzburg, Würzburg, Germany, 3Experimental Physics 5, University of Würzburg, Germany, 4Magnetic Resonance and X-ray Imaging MRB, Development Center X-ray Technology EZRT Fraunhofer Institute for Integrated Circuits IIS, Würzburg, Germany |
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Currently available T1 mapping techniques have only restricted capabilities for the visualization of the right myocardium and they have the limitation that after contrast agent application the T1-contrast between blood pool and fibrotic myocardium is partially very low. The quasi black blood TRASSI sequence shows improved abilities for the visualization and T1-quantification of myocardial structures. So it might be suited in clinical routine for a clear visualization of the right myocardium or for the detection of slight endocardial infarctions, because it is an ultra-fast and robust cardiac T1-mapping method with a total acquisition time of less than 7s. |
| 2735 | T1 Errors from Off-Resonance Effects for MOLLI at 3T: Experience in a Clinical Study | |
1Biomedical Engineering, University of Alberta, Edmonton, AB, Canada, 2Medicine, University of Alberta, Edmonton, AB, Canada, 3Medicine, University of Calgary, Calgary, AB, Canada |
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The widely used MOLLI (MOdified Look-Locker Inversion recovery) T1 mapping approach underestimates T1 values as a function of several factors, including off-resonance frequency. Native T1 and matched off-resonance frequency (Δω) maps were acquired in 24 subjects as part of a study of patients with kidney disease (3T field strength). Δω within individuals had an average range 133±43Hz, and Δω was significantly correlated with underestimation of native T1, in good agreement with Bloch equation simulations. ~50% of slices had relatively large (75-150 Hz) off-resonance frequencies, for which T1 errors ranged from -25ms to -150ms. |
| 2736 | Multi-Slice GRE-MOLLI at 3T using Denoising with Low-Rank and Sparsity Constraints | |
1Radiology, Massachusetts General Hospital, Boston, MA, United States, 2Harvard Medical School, Boston, MA, United States |
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Modified Look-Locker inversion recovery (MOLLI) uses bSSFP readout due to its high SNR, however, bSSFP is sensitive to off-resonance effects which result in banding artifacts. Recently, GRE has been proposed as an alternative readout for MOLLI, however, the low SNR efficiency of GRE-MOLLI is still a major problem. In this work, we propose to use a denoising reconstruction framework with low-rank and sparsity constraints to improve the low SNR of GRE-MOLLI. The proposed denoising method improved the low SNR of GRE-MOLLI, and multi-slice GRE-MOLLI is feasible for artifact-free T1 mapping with wider spatial coverage at high magnetic fields ($$$\geq 3T$$$). |
| 2737 | Prognostic value of cardiac MR imaging for end-stage phase of hypertrophic cardiomyopathy patients with or without adverse ventricular remodeling | |
1Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China, 2Fuwai Hospital,Chinese Academy of Medical Sciences and Peking Union Medical College |
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Cardiac morphology as well as LGE extent proved to be particularly heterogeneous in ES phase of HCM patients. For ES phase of HCM patients with adverse ventricular remodeling, LGE was a significant predictor of poor outcomes. But for ES phase of HCM patients without ventricular dilatation, biatrial enlargement, extremely diastolic dysfunction and higher incidences of AF may contribute more to adverse prognosis. |
| 2738 | CMR-Derived Regional T2, T1/ECV, Myocardial Velocities, and Dyssynchrony Influenced by Donor and Recipient Characteristics after Heart Transplantation | |
1Radiology, Northwestern University, Chicago, IL, United States, 2Cardiology, Northwestern University, Chicago, IL, United States |
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Cardiac MRI is increasingly being used for cardiac allograft surveillance following transplantation, so it is important to investigate which recipient and donor characteristics influence several CMR parameters: global ventricular function, myocardial velocities, dyssynchrony, T2, native T1, and ECV. Notable associations with T2 included donor age, normalized recipient-donor age difference, and recipient weight. Peak diastolic longitudinal velocity was associated with donor age and cold ischemic time. |
| 2739 | Non-contrast T1 mapping can detect myocardial fibrosis in hypertrophic cardiomyopathy without gadolinium. Is native T1 a superior alternative to late gadolinium enhancement? | |
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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Native T1 mapping is a novel cardiac magnetic resonance technique for myocardial tissue characterization without contrast administration. Native T1-mapping in hypertrophic cardiomyopathy was correlated with T1 map-based extracellular volume fraction, and native T1 of apparently late gadolinium enhancement (LGE)-negative segments were significantly longer than normal myocardium. Therefore, native T1 mapping has the potential to quantify the volume of interstitial space without gadolinium, which would be useful particularly in patients who are limited in use of gadolinium. Furthermore, native T1 would be a useful biomarker for the detection of diffuse myocardial damage difficult to evaluate using conventional LGE alone. |
| 2740 | Assessment of myocardial inflammation in cardiac sarcoidosis using early gadolinium enhancement | |
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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In patients with cardiac sarcoidosis, assessment of the activity of myocardial inflammation is as crucial as the choice of therapeutic strategy and monitoring of therapeutic effects. It is known that early gadolinium enhancement (at 2–5 minutes after gadolinium administration) can visualize myocardial inflammation and/or edema such as in acute myocarditis and acute myocardial infarction. In this study, images of gadolinium enhancement at 2 minutes delay were significantly associated with findings regarding active inflammation, suggesting that early gadolinium enhancement has the potential to act as a marker of inflammation activity in cardiac sarcoidosis. |
| 2741 | Simple quantification using the myocardium-to-lumen signal ratio in diffuse myocardial fibrosis of non-ischemic cardiomyopathies: Correlation with T1 mapping derived ECV | |
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 T1 mapping has recently been applied to the quantification of extracellular volume fraction (ECV) and has shown potential for the detection of myocardial fibrosis. However, for the measurement of ECV, additional scans of pre- and post-contrast T1 mapping are necessary, and the post-processing procedure is time consuming. In this study, the myocardium-to-lumen signal ratio (M/L) in conventional late gadolinium enhancement images with fixed inversion time showed acceptable levels of correlation with ECV obtained by the T1 mapping in non-ischemic cardiomyopathy, suggesting that M/L has the potential to allow for simple quantification of the fibrotic change in non-ischemic cardiomyopathies. |
| 2742 | Assessment and detection of left ventricular thrombus in patients with acute ischemic stroke using cardiac MR (ADVENT study) | |
1Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 2Division of Neurology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, 3Division of Cardiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan |
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In patients with acute ischemic stroke (AIS), the assessment of left ventricular thrombus (LVT) is essential. In this study, we showed the utility of the early phase of gadolinium enhancement for detecting LVT in AIS patients, which conventional TTE hardly identified. CE-CMR, when using the early phase of gadolinium enhancement, should be performed on acute ischemic stroke patients, especially those with prior myocardial infarction or LV dysfunction and without definitive stroke etiologies. |
| 2743 | A 2D combined myocardium T1 and T2 mapping | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, People's Republic of China |
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In this study, we developed a 2D combined myocardial T1 and T2 mapping sequence that uses a combination of saturation pulse and T2 preparation pulse and allows simultaneously obtaining T1 and T2 map with acceptable breath holding time (12 heartbeats). High quality multiple T1 and T2 weighted images were obtained in the other cardiac cycle between the saturation pulse and T2 preparation pulse. Phantom experiment showed that T1 and T2 measured by proposed method highly correlated with reference methods. In vivo experiment showed that the proposed sequence can yield comparable myocardium T1 and T2 values with the conventional separated T1 and T2 mapping sequences. |
| 2744 | An in-vivo comparison of STEAM and 2nd order motion compensated spin-echo imaging in multi-phase cardiac DTI at 3T | |
1Cardiovascular 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 |
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Cardiac diffusion tensor imaging (cDTI) is a novel non-invasive method of interrogating myocardial microstructure that has seen a recent surge in interest. Many of the most interesting clinical results were obtained using stimulated echo acquisition mode (STEAM) imaging at multiple cardiac phases. Recently however, spin-echo cDTI with second order motion compensated diffusion gradients (M012-SE) was proposed. In this study we report results of a comparison of M012-SE and STEAM imaging in multiple cardiac phases at 3T in 15 healthy subjects with matched sequence parameters. While M012-SE provides comparable quality data in systole, STEAM is the more reliable technique in diastole. |
| 2745 | Integrated Analysis of Cardiac Genetic and Structural Alterations in Left Ventricular Hypertrophy using the Supertoroidal Model | |
1Harvard Medical School - Massachusetts General Hospital, Boston, MA, United States, 2Brigham and Woman’s Hospital, Harvard Medical School, Boston, MA, United States, 3Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States, 4University of São Paulo, São Paulo, Brazil |
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Response to disease occurs over many scales ranging from individual gene expression to whole organ physiology. We employed the supertoroidal model of the diffusion tensor to study the interaction between gene expression and microstructure of the heart. Left ventricular hypertrophy (LVH) was induced in C57Bl6 mice through aortic banding, and characterization of the cardiac microstructure was performed in vivo with DTI. The supertoroidal model was constrained by both diffusion information and gene expression data related to cardiomyocyte hypertrophy and myofiber orientation. Our model enabled further characterization of LVH by unifying information at different scales and across domains. |
| 2746 | Segment and sexual variation of myocardium in T1 mapping and extracellular volume fraction with cardiovascular magnetic resonance in healthy volunteers | |
1Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wu Han, People's Republic of China, 2MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China |
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This study aimed to evaluate sex and segment differences of myocardium in native T1 value and ECV in healthy volunteers. We measured native T1 value of 425 segments and ECV of 424 segments. The results showed that myocardial ECV of females was higher than that of males in basal, middle and apical segments. The ECV of the apical segments was higher than in the basal and middle segments. The mean native T1 value and ECV were not associated with age, ejection function(EF), end diastolic volume(EDV), end systolic volume(ESV), and stroke volume(SV). |
| 2747 | Role of free-breathing motion-corrected phase-sensitive inversion recovery (MOCO-PSIR) imaging technique for the assessment of late gadolinium enhancement | |
1Department of Radiology, Zhongshan Hospital, Fudan University, Department of Medical Imaging, Shanghai Medical school, Fudan University and Shanghai Institute of Medical Imaging, Shanghai, People's Republic of China, 2MR Research and Development, Siemens Healthcare, Los Angeles, CA, United States, 3Application development, Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, People's Republic of China |
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We aimed to investigate the role of motion-corrected phase-sensitive inversion recovery (MOCO-PSIR) technology for the evaluation of LGE. LGE imaging was conducted in 55 patients with MOCO-PSIR and conventional breath-hold PSIR sequences successively. Image quality was scored using a four-point scale. Compared with conventional PSIR, MOCO-PSIR showed better image quality and detected larger LGE volumes in nonischemic cardiomyopathy. Free-breathing motion-corrected PSIR method is a promising alternative to conventional PSIR sequence. |
| 2748 | Myocardial fat quantification of normal subjects via 7-peaks mDixon model | |
1Executive Health Management Center, Cheng Ching Hospital, Taichung, Taiwan, 2Philips Healthcare, Taipei, Taiwan, 3Philips Healthcare, Hong Kong |
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Cardiac magnetic resonance imaging provides a lot of physiological information about myocardial pathology, and the mDixon technique also has been developed on cardiac application recently. The fat deposition in myocardium is possibly related with cardiomyopathy, so it is important to determine the fat composition of myocardium. The mDixon provides an easy way to acquire such this information within one breath hold, and it has a consistent result with magnetic resonance spectroscopy from the previous study. Also it has been reported that multipeak fat spectrum model gives more robustness, and 7-peaks model is used in this study. The aim of this study is to evaluate fat fraction of myocardium with 7-peaks model. |
| 2749 | Reperfusion Hemorrhage Following Prolonged Myocardial Ischemia Leads to Fatty Degeneration of Myocardial Infarctions via Iron-Mediated, Self-Perpetuating Loop of Foam Cell and Ceroid Accumulation | |
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 2Louisiana State University |
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Fatty infiltration within chronic myocardial infarctions (MI) is a common finding. It is typically observed in the peri-infarct border zone of old scars and has been linked to adverse outcomes in the chronic post-MI setting. To date, the trigger for fat deposition within old MI is unknown. Recent reports showed that iron deposits from hemorrhagic MI drive the recruitment of new monocytes/macrophages into the infarcted territory throughout the chronic phase after MI. Since iron-laden macrophages (siderophages) are prone to transforming into foam cells, we hypothesized that fatty degeneration of hemorrhagic myocardial infarctions has its origin in iron-driven foam cell formation. |
| 2750 | Cardiomyopathy in later-onset Fabry disease: a correlative study of T1 mapping on MR and histology | |
1Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, 2School of Medicine, National Yang Ming University, Taipei, Taiwan, 3Department of Medical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan, 4Pathology, Taipei Veterans General Hospital, Taipei, Taiwan, 5Pediatrics, Taipei Veterans General Hospital, Taipei, Taiwan, 6Radiology, Kaohsiung Veterans Genertal Hospital, Kaohsiung, Taiwan, 7GE Healthcare, Taipei, Taiwan, 8GE Healthcare MR Research China, Beijing, China |
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Fabry disease is a rare and X-linked disorder characterized by accumulation of glycosphingolipid within lysosomes and resultant multiple organ damage including heart. Since lipid is known to shorten the MRI parameter T1, non-contrast T1 mapping has emerged as key imaging modality to assess Fabry cardiomyopathy and early detection of lipid deposition. This study provides a histologic validation of 7 male patients of untreated later-onset Fabry disease to demonstrate the negative correlation between native myocardial T1 value and severity of lipid deposition (correlation coefficient, -0.771; p, 0.042) and justifies the application of T1 mapping as a noninvasive predictor of surveillance strategy. |
| 2751 | Cardiac MR Derived Extracellular Volume Measurements Using Different Contrast Agents | |
1Department of Radiology, Northwestern University, Chicago, IL, United States |
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T1 and ECV values calculated from gadoterate meglumine enhanced CMR are comparable to more routinely used gadopentetate dimeglumine and gadobutrol CMR measurements. |
| 2752 | Single Breath-hold Measurement of T2 Corrected Myocardial Proton Density Fat Fraction in Humans at 3T | |
1BMIB, NIDDK, Bethesda, MD, United States, 2Metabolic Unit, NIDDK, MD, United States |
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Localized 1H-MRS was used to determine T2s for water and lipid signals in the human heart in a single breath hold and derive relaxation corrected proton density fat fractions. |
| 2753 | A Versatile MOLLI-based Inversion Time (TI) scout sequence for Myocardial Nulling Determination in emerging Late Gadolinium Enhanced CMR Variants: A Phantom Study | |
1Medicine, The University of Chicago, Chicago, IL, United States, 2Radiology, The University of Chicago, Chicago, IL, United States, 3Philips HealthTech, Cleveland, OH, United States |
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A Look-Locker scout is used for optimal inversion time (TI) determination of myocardial nulling in Late Gadolinium Enhancement (LGE) Cardiac Magnetic Resonance. Recently, novel LGE technique variants such as the Wideband approach have been proposed, and these approaches can lead to variability in the signal evolution between the Look-Locker TI-scout and LGE. In this study, we propose a Modified Look-Locker Inversion (MOLLI)-based TI-scout that closely matches its signal evolution to that of any LGE variant. Bloch simulation and phantom evaluation are performed to compare the null-times from the conventional LL-based and proposed MOLLI-based approaches against the LGE protocol over a range of clinically relevant T1 values observed in viability imaging. |
| 2754 | Free-breathing native cardiac T1 and T2 mapping with flexible elastic image registration: Preliminary Clinical Result | |
1Philips Healthcare, Singapore, Singapore, 2National Heart Centre Singapore, Singapore, Singapore, 3Philips Healthcare, Japan, 4Philips Research, Hamburg, Germany, 5National Heart Centre Singapore, Singapore, 6Vanderbilt University, United States |
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Current myocardial T1 and T2 mapping based on inversion-recovery and single-shot readout techniques require generally at least 7 to 10 seconds breath hold. Improper and difficulties of breath hold is one of the main sources of error and reduced reproducibility. To mitigate the dependence of mapping on breath holds and also to increase patient comfort, we report free-breathing T1 and T2 mapping using different acquisition schemes using flexible elastic image registration. We demonstrate the feasibility of this approach with motion correction for increased image quality and quantification accuracy. |
| 2755 | The Correlation of Clinical and Image of Acromegaly Patients Based on 3.0T Cardiac Magnetic Resonance Quantitative Analysis of Myocardial T1 and Extracellular Volume | |
1Radiology, PUMCH, Beijing, People's Republic of China, 2Neurology, PUMCH, 3MR Collaborations NE Asia, Siemens Healthcare |
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The aim of this study was to find out if there might be some correlation between clinical information and image measurements for acromegaly patients. And it found that for acromegaly patients, the basal slice of heart might be the most involvemented position, and its contractility had a positive correlation with GH burden, and both T1 and ECV had a negative correlation with IGF-1. And we need to enlarge the sample size and compare the changes before and after the surgery in order to give more informations to the clinicians. |
| 2756 | SMART1Map: Accuracy and Influencing Imaging Parameters For Cardiac T1 Mapping. | |
1MRI Research, University Children Hospital, Zurich, Switzerland, 2BioFlow, University Picardie Jules Verne, Amiens, France, 3Cardiology, University Children Hospital, Zurich, Switzerland |
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SMART1Map sequence was performed on 6 phantoms with different T1 values. Sixteen schemes were prescribed: 4 heart rates (60, 80, 100, 120 bpm), 2 spatial resolutions (FOV = 30 cm and FOV = 48 cm) and 2 cardiac phases (systole and diastole). The results show that SMART1Map underestimates long T1 (native T1 myocardium) at any scheme. We also found an increase in error with reduced FOV (all other parameters being identical), and an influence of the cardiac phases on T1 at the levels of native and post-contrast blood and myocardium |
| 2757 | An alternative T1 estimation algorithm with a higher flip angle improves T1 mapping accuracy and precision of the MOLLI sequence | |
1Radiology, University of California, Los Angeles, Los Angeles, CA, United States, 2Division of Cardiology, University of California, Los Angeles, Los Angeles, CA, United States |
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Good T1 estimation accuracy and precision is important for clinical application of the myocardial T1 mapping technique. Although the widely used T1 mapping technique, modified Look-Locker |
| 2758 | Coronary artery disease is not related to pathologic epicardial fat volumes, left ventricular strain or T1-relaxation times in hypertensive patients | |
1Radiology, University Hospital Bonn, Bonn, Germany, 2Philips Healthcare, Hamburg, Germany |
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Hypertension is related to increased amounts of epicardial fat, to myocardial fibrosis and to left-ventricular contractility disturbances despite a normal systolic left-ventricular ejection fraction. However, the presence of stable coronary atherosclerotic disease in general - and with no cardiac damage due to prior coronary pathologies - does not additionally affect these parameters. |
| 2759 | 3D High Frequency Cardiac Magnetic Resonance Elastography Quantitatively Differentiates Myocardial Stiffness in Patients with HFPEF and Healthy Volunteers | |
1Radiology, Mayo Clinic, Rochester, MN, United States, 2Cardiovascular Diseases, Mayo Clinic, 3Biomedical Engineering and Physiology, Mayo Clinic |
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Increased myocardial stiffness in patients with heart failure with preserved ejection fraction (HFpEF) is known to affect diastolic filling. The purpose of this work was to determine if 3D high frequency cardiac MR elastography (MRE) can quantitatively differentiate increased myocardial stiffness in HFpEF patients compared to healthy volunteers. Two patients with clinical diagnosis for HFpEF and 47 healthy volunteers were studied. The myocardial stiffness of HFpEF patients (mean: 10.57 kPa) was found to be significantly stiffer (p < 0.05) than healthy controls (mean: 7.79 kPa). Recruitment of more HFpEF patients is underway for further validation of this finding. |
| 2760 | Reconstructing Inherent Stiffness in a Deforming Heart Phantom using MR Elastography | |
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom |
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Cardiac MR-Elastography has significant potential to provide a non-invasive measure of myocardial tissue health. A core challenge in its application is the substantial motion of the heart over the cardiac cycle, which introduces a bias in the quantified apparent stiffness. In this work we apply a reconstruction technique for MRE designed to correct changes in apparent stiffness due to deformation. The reconstruction method is tested on anatomically accurate homogeneous and heterogeneous heart phantoms that are inflated to mimic diastolic function. The results demonstrate the ability of the reconstruction technique to retrieve intrinsic stiffness values, even under substantial inflation. |
| 2761 | Comparison of SASHA and MOLLI sequences for Iron Quantification in the Myocardium. | |
1Medical Physics Department, Guy's and St Thomas' Hospital, London, United Kingdom, 2Department of Medical Physics and Bioengineering, Division of Imaging Sciences and Biomedical Engineering, King’s College London, London, United Kingdom, 3Philips Healthcare, Surrey, United Kingdom, 4Cardiology Department, King’s College Hospital, United Kingdom, 5Division of Imaging Sciences & Biomedical Engineering, King’s College London, London, United Kingdom, 6Department of Pediatric Cardiology, University of Texas Southwestern, TX, United States |
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Development of T1 mapping in the myocardium in recent years has demonstrated that the technique can add information to inform the diagnosis or management of patients in a number of pathologies. Sequences have been developed to enable T1 mapping of the myocardium within a single breath-hold and the limitations of these sequences have been well characterized. Recent studies have investigated myocardial T1 mapping in iron overload patients using variants of the MOLLI sequence. These studies have concluded that T1 mapping could be more sensitive and reproducible than T2* mapping for the measurement of iron overload in the myocardium. The current study aims to determine the optimal T1 mapping sequence for iron overload. Simulations, phantom studies and in-vivo studies were carried out to investigate MOLLI and SASHA sequences used for T1 mapping of low T1 and T2 tissues (comparable to iron overload in the myocardium). |
| 2762 | Optimization of MOLLI reconstruction for free-breathing myocardial T1 imaging | |
1Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan |
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The free-breathing MOLLI (FB-MOLLI) presented in our previous study allowed T1 mapping in vivo without breath-hold. In this study, we attempted to implement unsupervised reconstruction for FB-MOLLI data sets and used a deformable method for image registration to improve the reliability of free-breathing T1 mapping. The results supported that the method improved the image alignments of the FB-MOLLI data sets and thus increased the quality of the T1 map. The variations of the repeated T1 measurements were significantly reduced in the anterolateral of the LV walls. |
| 2763 | Derivation and Validation of Synthetic Hematocrit Calculation from Blood Pool T1 values at multiple different cardiac blood pools, in both high and low flow states on 3T MRI | |
1Radiology, Northwestern University, Chicago, IL, United States, 2Siemens Medical Solutions, 3Northwestern University |
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Comparison of the relationship between blood R1 and venous derived hematocrit in the left ventricle, left atrium, descending thoracic aorta, and short axis (apex, mid, and base) blood pools. |
| 2764 | Dual identity of the interventricular septum with in vivo diffusion tensor imaging | |
1Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom, 2NHLBI, National Institutes of Health, MD, United States |
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Heart muscle has a complex cellular helical arrangement, where bundles of myocytes, known as sheetlets interleave with collagen-lined shear layers. The right and left ventricle form separately in early stages of cardiogenesis, resulting in a dual inter-ventricular septum. In this work we compare the myocyte and sheetlet microstructure in the septum and LV free-wall in healthy and HCM hearts with in vivo diffusion tensor imaging. Results show that the right-side of the interventricular-septum has myocyte orientations not seen in the free-wall, and also lower sheetlet angles, which may indicate an RV identity in this region. |
| 2765 | A Cost-effective 3D Printed Cardiac MR Phantom | |
1Medical Imaging Research Centre, Dayananda Sagar Institutions, Bangalore, India, 2Wipro-GE, Bangalore, India, 3Embedded Systems, Dayananda Sagar University, Bangalore |
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Cardiac phantoms have been employed as testing and validating tools for newly developed techniques focused on sampling and reconstruction strategies. In this work, a 3D printed cardiac phantom was built to mimic the human heart. This was achieved through the integration of a peristaltic pump. Results depict the structural and functional behavior of the cardiac phantom, based on MR imaging on 1.5T scanners from 2 vendors. Ongoing work involves implementing the post-processing pipeline to correlate UI parameters with those derived from images. Future work focuses on employing PVA for preparing the heart model employing the 3D printing heart mold. |
| 2766 | Inter-Scanner T1 and T2 Measurement Variability Evaluation on Two 3T Scanners with Identical Hardware and Software Configuration | |
1Radiology, Mayo Clinic, Scottsdale, AZ, United States |
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Inter-scanner T1 and T2 measurement variability was evaluated on two 3T scanners with identical hardware and software configuration to identify the most robust combination of sequence, parameters and post-processing that produces accurate measurement and to establish confidence intervals for T1 and T2 measurements for in-vivo studies by incorporating “native” inter-scanner variability. |
| 2767 | Cardiac T1 Mapping Using True Hybrid Inversion and Saturation Recovery | |
1GE Healthcare, Bethesda, MD, United States, 2GE Global Research, Munich, Germany, 3GE Healthcare, Waukesha, WI, United States, 4GE Healthcare, Menlo Park, CA, United States |
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Despite limited accuracy, MOLLI remains popular for T1 mapping due to high precision and visual quality of the maps. This is due primarily to the large dynamic range afforded by the inversion-recovery (IR) acquisition. Methods using saturation-recovery (SR) have better T1 accuracy but have relatively poor precision compared with MOLLI. This work presents a true hybrid IR/SR acquisition that targets the optimal regions of both the IR and SR relaxation curves, employs a novel method for maximizing dynamic range, and uses an improved sampling strategy. The proposed hybrid method combines the accuracy of single-point SR with the precision of IR. |
| Exhibition Hall | Thursday 8:15 - 10:15 |
| 2768 | Identification of Intrapalque Hemorrhage in Carotid Artery by Simultaneous Non-contrast Angiography and intraPlaque hemorrhage (SNAP) Imaging: A Comparison Study with MP-RAGE | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China, 2Beijing Institute for Brain Disorders, Beijing, People's Republic of China, 3Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China, 4Department of Radiology, University of Washington, Seattle, WA, United States |
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It is important to accurately identify carotid artery intraplaque hemorrhage (IPH) due to its significant association with ischemic stroke. MP-RAGE sequence has been demonstrated to be the best approach to detect carotid IPH. Recently, investigators proposed SNAP imaging technique which allows non-contrast MR angiography and identifying IPH simultaneously. This study sought to investigate the performance of SNAP imaging in detecting carotid IPH by comparing with MP-RAGE. We found that SNAP imaging detected more IPHs and showed larger IPH size than MP-RAGE, suggesting SNAP imaging might be a sensitive imaging tool to detect IPH. |
| 2769 | Predicting Procedure Successful Rate after Endovascular Recanalization for Chronic Carotid Artery Occlusion by 3D Vessel Wall Imaging | |
1Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China, 2Neurosurgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China, 3MR Clinical Science, Philips Healthcare, Greater China, People's Republic of China, 4Center for Biomedical Imaging Research,Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China, 5University of Washington, WA, United States |
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Endovascular recanalization in patients with carotid chronic total occlusion (CTO) has been reported to be technically challenging. In this study, we retrospectively analyzed the 3D vessel wall imaging in patients with carotid CTO and its relationship to technical success rates. A total of 15 consecutive carotid CTO recanalization attempts were performed with overall technical success rate 60.0%. Compared with failure group, patients with an occlusion length <50mm, distal true lumen visibility in C1 segment on MR vessel wall images had a higher rate of successful recanalization. 3D vessel wall MR imaging may play a role in patient selection of endovascular recanalization in patients with carotid CTOs. |
| 2770 | Distribution and burden of atherosclerosis in patients with anterior circulation cerebral ischemic events: Characterization using combined extracranial and intracranial vessel wall MRI | |
1University of Washington, Seattle, WA, United States, 2Tangshan Gongren Hospital, Tangshan, People's Republic of China |
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Both extracranial and intracranial atherosclerosis may be implicated in large-artery atherothrombotic stroke. This proof-of-concept study characterized the distribution and burden of atherosclerosis in thirteen patients with anterior circulation cerebral ischemic events using combined extracranial and intracranial vessel wall MRI. We found that atherosclerotic plaques were highly prevalent in both extracranial and intracranial carotid arteries. Larger plaque burden measured as plaque index on black-blood vessel wall MRI, rather than luminal stenosis on time-of-flight MRA, was significantly associated with clinical symptoms. Black-blood vessel wall MRI may be useful in identifying the culprit plaque in patients with suspected large-artery atherothrombotic stroke. |
| 2771 | Reproducibility of Semi-automatic Carotid Intraplaque Hemorrhage Quantification using SNAP MRI | |
1University of Washington, Seattle, WA, United States |
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Intraplaque hemorrhage (IPH), a characteristic feature of high-risk atherosclerosis, can be identified as hyperintensity areas on T1-weighted MRI. Simultaneous Non-contrast Angiography and intraPlaque hemorrhage (SNAP) MRI has been shown to provide comparable IPH detection as MPRAGE with additional benefit of lumen assessment in the same scan. In this study, we developed a semi-automatic method to detect and quantify IPH on SNAP MRI with histology confirmation. An objective IPH detection threshold was identified and high scan-rescan reproducibility was obtained for semi-automatic IPH volume measurement and maximum IPH intensity. |
| 2772 | MR Imaging of Vasa Vasorum During Lipid-Lowering Therapy to Carotid Unstable Plaque: A Prospective Study in Chinese Patients | |
1Bethune international peace hospital, Shi jiazhuang, People's Republic of China, 2Chinese PLA general hospital |
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Carotid plaque vasa vasorum angiogenesis from adventitia may be influenced by inflammation, could promote intraplaque hemorrhage and decrease the thickness of fibrous cap, finally, the cap is prone to rupture. Drug therapy and assessment to the vulnerable plaque, in vivo, would be of major clinical interest. To investigate whether lipid therapy leads to changes in vasa vasorum characteristics of carotid unstable plaque in chinese patients, as measured by using dynamic contrast-enhanced (DCE) MRI. Focus on inflammation to monitor the early beneficial therapy using vasa vasorum MR imaging, biomarker in vivo. |
| 2773 | Assessment of aortic pulse wave velocity in patients with peripheral artery disease | |
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Department of Medicine, University of Pennsylvania, Philadelphia, PA, United States, 3Department of Anesthesiology, Stony Brook University, Stony Brook, NY, United States |
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Pulse wave velocity (PWV) provides a measure of arterial stiffness by quantifying the propagation velocity of the systolic pressure wave along the arterial wall. Prior studies have reported that PWV is elevated in patients with peripheral artery disease (PAD), and here we sought to determine whether the elevation in PWV is correlated with PAD disease severity as measured by the ankle-brachial index (ABI). No correlation was observed between ABI and PWV, suggesting that the systemic nature of atherosclerosis may be contributing to the increase in PWV more than the specific lesions that result in a reduction in ABI. |
| 2774 | 3D black-blood DCE-MRI using radial stack-of-stars acquisition and CS reconstruction: application in carotid and femoral arteries | |
1Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, Netherlands, 2Department of Vascular Medicine, Academic Medical Center, Amsterdam, Netherlands, 3Department of Radiology, Academic Medical Center |
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We implemented a high temporal resolution 3D black-blood protocol for DCE imaging of atherosclerotic plaques using a combination of a radial stack-of-stars sampling scheme, motion-sensitised (iMSDE) blood suppression and CS reconstruction. Using this approach, 3D black-blood DCE images with a temporal resolution of 12s could be obtained. In this work, we show the application of our method in patients with femoral and carotid artery plaques. |
| 2775 | Robust fat suppressed direct thrombus imaging (MPRAGE) sequence with a large field-of-view at 3T | |
1Kumamoto Chuo Hospital, Kumamoto, Japan, 2Philips Electronics Japan, Tokyo, Japan |
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MR plaque imaging is promising for characterizing atherosclerotic plaque. We proposed direct thrombus imaging (MPRAGE), based on mDIXON turbo field-echo sequence, could provide more robust and stable black-blood imaging with a large field-of-view compared with conventional sequences. |
| 2776 | Molecular Magnetic Resonance Imaging of Vascular Myeloperoxidase Activity for the Identification of Unstable Atherosclerotic Plaque | |
1Vascular Biology Division, Victor Chang Cardiac Research Institute, Sydney, NSW, Australia, 2Biological Resources Imaging Laboratory, University of New South Wales, Sydney, Australia, 3Department of Physics, Centre for Beam Applications, National University of SIngapore, Singapore, Singapore |
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Non-invasive imaging of unstable atherosclerotic plaques prone to rupture remains an unmet need in clinical cardiology. This is because current imaging modalities provide information on plaque burden, luminal stenosis and calcification, whereas they have limited ability to discern unstable from stable plaques. We used the tandem stenosis mouse model of unstable plaque in conjunction with MRI and a sensor (bis-5-hydroxytryptamide-DTPA-Gd) for the activity of the inflammatory enzyme myeloperoxidase. Our results reveal sustained and greater enhancement of unstable experimental plaque with the targeted sensor compared with its non-targeted analog (DTPA-Gd), and these results were confirmed by separate biochemical and histological analyses. |
| 2777 | Motion Insensitive 3D Multiple Echo Inversion Recovery Stack of Star(ME IR SOS) technique for measurement of T2* in Intraplaque Hemorrhage(IPH) | |
1UCAIR, Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States, 2Siemens Healthcare, 3Department of Veterans Affairs, VASLCHCS |
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The purpose of this work was to develop a 3D ME IR SOS technique to reduce off resonance blurring and allow measurement of T2* in Atherosclerotic plaque. In a prior study we observed lower ADC values in symptomatic IPH. We hypothesized that the T2* measurements from 3D ME IR SOS would help identify IPH and further characterize symptomatic and asymptomatic IPH. The 3D ME IR SOS can provide motion insensitive IPH visualization and T2* values simultaneously which may provide important clinical information to detect the plaque progression. |
| 2778 | 3D visualization of Vascular Cell Adhesion Molecule-1 (VCAM-1) specific Ultrasmall Superparamagnetic Iron Oxide (USPIO) nanoparticles in the atherosclerotic mouse with accelerated self-navigated radial 4D-MRI. | |
1Medizinische Klinik und Poliklinik I, Universitätsklinikum Würzburg, Würzburg, Germany, 2Experimentelle Physik V, Universität Würzburg, Würzburg, Germany, 3Institut für Diagnostische und Interventionelle Neuroradiologie, Universitätsklinikum Würzburg, Würzburg, Germany, 4Fraunhofer IIS, Fraunhofer EZRT, Magnetresonanz- und Röntgenbildgebung (MRB), Würzburg, Germany |
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USPIO-based, functionalized contrast agents targeting VCAM-1 enable the visualization of inflamed areas in the vessel wall during early atherogenesis. We present a novel 3D technique for coverage of the whole aortic arch at high spatial resolution and a time-resolved detection of nanoparticles with an ECG-free flow-compensated radial 3D-Cine acquisition. T2* weighted 3D-Cines were acquired using two different gradient echoes to provide phase difference maps. The results indicate a reliable detection of the nanoparticles with the new method due to a true 3D coverage of the aorta and the additional phase information. |
| 2779 | Gradient Echo Derived Multi-Contrast Imaging for Carotid Atherosclerosis Assessment | |
1Philips Research China, Shanghai, People's Republic of China, 2Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China, 3Vascular Imaging Lab, Department of Radiology, University of Washington, Seattle, WA, United States |
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In this work, we developed a post processing framework to generate multi-contrast images from a single three dimensional MR scan of multi-echo gradient echo sequence, which can alleviate the registration problem and further improve the scan efficiency with a total scan time of 3min22sec for carotid atherosclerosis imaging. The initial experiments has demonstrated its feasibility for vessel wall delineation and its potential for plaque component characterization. |
| 2780 | Quantitative characterization of calcified and lipid-laden blood clot in vitro at 3T | |
1Imaging Research Laboratories, Robarts Research Institute, Western University, London, ON, Canada, 2Dept. of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada, 3Dept. of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada, 4Dept. of Clinical Neurological Sciences, Western University, London, ON, Canada |
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Thrombus composition in embolic occlusion, particularly the presence of thrombolysis-resistant components such as calcium and fat, can significantly influence treatment efficacy, yet current MR methods for inferring composition are qualitative and sensitive only to red blood cells. We examined the ability of novel post-processing algorithms applied to a tailored GRE acquisition to discriminate and quantify important components within in vitro blood clots of varied hematocrit over a nine-day ageing period. Calcium and lard were readily discernable throughout the experiment, while clots were differentiable from one another between two to six days, demonstrating this protocol's potential for thrombus characterization in vivo. |
| 2781 | Optimization of whole-brain intracranial arterial wall imaging sequence using Bloch equation simulation | |
1Paul C. Lauterbur Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China, 2Neurology, Shenzhen Second People’s Hospital, Shenzhen, People's Republic of China |
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T1 weighted SPACE has gain popularity in intracranial wall imaging, but its long scan time makes it impractical and its multiple parameters make it very difficult to be optimized. In this study, we looked into the effect of various imaging parameters of T1w SPACE on the signal-to-noise (SNR) and contrast ratio (CR) between vessel wall and cerebrospinal fluid using Bloch equation simulation. An optimized whole-brain intracranial artery wall imaging protocol which had comparable higher CR and SNR within 8min and 0.55mm iso resolution was found. The simulation results were verified by the volunteer study and matched the experiments well. |
| 2782 | Assessment of Local Pulse-Wave-Velocity Distribution in Mice using k-t BLAST MRI with Semi-Automatic Area Segmentation | |
1Department of Physics, University of Würzburg, Würzburg, Germany, 2Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany, 3Department of Internal Medicine I, Division of Cardiology, University Hospital Würzburg, Würzburg, Germany |
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Arterial stiffness (AS) assessed by pulse wave velocity (PWV) has been shown to represent a valuable biomarker of cardiovascular disease risk. Local elastic properties of the murine aortic vessels such as the pulse-wave-velocity (PWV) can be examined using PC-MRI [1]. In the present study we provide an accelerated method based on a k-t BLAST undersampling scheme combined with a new semi-automatic segmentation algorithm to quantify the distribution of the local PWV along the aortic vessel. |
| 2783 | Improvement of fat separation for simultaneous carotid and intracranial vessel wall imaging by dual-echo fat-water imaging | |
1Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China |
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In this study, we used dual-echo fat-water imaging technique in variable flip angle turbo spin echo sequence for simultaneous carotid and intracranial artery imaging to obtain fat-free vessel wall images. Results show that the technique was promising for simultaneous carotid and intracranial vessel wall imaging to improve the SNR and better delineation of carotid vessel wall. |
| 2784 | 3D Golden-Angle Spiral Sparse Parallel-Imaging for Lumen Area Measurements of the Entire Proximal and Mid-Segments of the Coronary Arteries in a Breath-Hold | |
1Russel H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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Coronary artery endothelial function (CEF) could historically only be measured with invasive catheterization-based testing. Recently, 2-dimensional cine MRI in combination with isometric handgrip exercise was introduced to quantify CEF noninvasively. However, the MRI technique only assesses CEF at one or two locations in an artery and does not allow assessment of regional heterogeneity present throughout diseased vessels. The aim of this work was to develop high-resolution isotropic 3-dimensional cine coronary MRI that enables measures of coronary lumen area along the entire proximal and mid segments of the coronary arteries in a single breath-hold, a pre-requisite for future 3-dimensional CEF measurements. |
| 2785 | Identification of Carotid Lipid-Rich Necrotic Core by Three-Dimensional Magnetization-Prepared Rapid Acquisition Gradient-Echo Imaging | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, People's Republic of China, 2Department of Radiology, University of Washington, Seattle, WA, 3Department of Radiology, Peking University First Hospital, Beijing, People's Republic of China, 4Department of Radiology, Uppsala University Hospital, Sweden |
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Carotid atherosclerotic lipid-rich necrotic core (LRNC) is associated with ischemic cerebrovascular events. Currently, LRNC was mainly characterized by contrast-enhanced T1 weighted (CE-T1W) or T2 weighted (T2W) imaging. However, CE-T1W imaging needs gadolinium application and T2W imaging is challenging to identify LRNCs with long-T2 components. This study investigated the usefulness of MP-RAGE in identifying carotid LRNC by comparing with CE-T1W and T2W imaging. We found that LRNC had the lowest relative signal intensity against muscle or fibrous tissue on MP-RAGE images among three sequences (P<0.05), indicating that MP-RAGE might be a better non-contrast imaging tool to identify LRNC than T2W imaging. |
| 2786 | Comparison of black-blood T2 mapping sequences in carotid artery at 3T | |
1Department of Radiology, University of Cambridge, Cambridge, United Kingdom, 2Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom, 3GE Healthcare, Amersham, United Kingdom |
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Carotid black-blood quantitative T2 mapping sequences have the potential to help plaque component segmentation and are more suitable for multi-centre studies across different MRI systems. The purpose of this study is to compare the accuracy of three different black-blood quantitative T2 sequences in the phantom and healthy volunteers at 3T. |
| 2787 | Optimization of 3D black-blood multi-echo T2* weighted sequence in carotid artery | |
1Department of Radiology, University of Cambridge, Cambridge, United Kingdom, 2Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom |
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Carotid T2* weighted images have multiple applications, including differentiating plaque components and detecting ultrasmall superparamagnetic iron oxide (USPIO) contrast agents. The current work develops and |
| 2788 | Three-dimensional T1-Weighted Black-Blood Turbo Spin-Echo with Navigator Respiratory Gating for the Vessel Wall Imaging: A Novel Approach to Evaluate Plaque in the Aortic Arch | |
1Department of Radiological Technology, Kurashiki Central Hospital, Okayama, Japan, 2Department of Medical Technology, Kurashiki Central Hospital, Okayama, Japan |
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Complex plaques in the aortic arch on transthoracic echocardiography (TEE) can cause brain embolism. However, TEE, which is associated with a number of complications and contraindications, is not suitable for all patients. Therefore, we focused on contrast evaluation of MRI with 3D T1w black-blood TSE as an adjunct to diagnosis of complex plaques. The aim of this study is to clarify the optimal scan method for 3D T1w black-blood TSE. Our results suggest that 3D T1w black-blood TSE in the aortic arch can reduce the amount of artifact by using the optimal trigger timing by ECG-gating and navigator respiratory gating. |
| 2789 | Comparison of Two Different Implementations for the Simultaneous Non-Contrast Angiography and Intraplaque Hemorrhage (SNAP) Sequence | |
1Radiology and Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, 2Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, AB, Canada, 3Radiology, University of Washington, Seattle, WA, United States |
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We compare, using Bloch equation simulation, the relative signal in intraplaque hemorrhage (IPH), arterial wall (Wall) and Lumen (i.e., blood), along with the IPH–Wall contrast for two different implementations of the SNAP sequence. The first implementation is the original version (Ver1) that uses a linear phase-encoding scheme post-IR, whereas the second version (Ver2) uses centric slice-encodes post-IR. We show that, although Ver2 appears to be less time-efficient, it actually provides increased signal and contrast for the same acquisition time. |
| 2790 | Accelerated multi-contrast high isotropic resolution 3D intracranial vessel wall MRI using a tailored k-space undersampling and partially parallel reconstruction strategy. | |
1University of Washington, Seattle, WA, United States, 2Philips Healthcare, Beijing, People's Republic of China |
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Identification and differentiation of intracranial vessel wall pathologies requires multi-contrast high isotropic resolution 3D vessel wall MRI. However scan times for multi-contrast intracranial vessel wall imaging (IVWI) are too long to be tolerated by patients. We have developed a tailored k-space undersampling and partially parallel reconstruction strategy to accelerate 0.5mm 3D isotropic multi-contrast IVWI sequences to five minutes each. We demonstrate an accelerated multi-contrast IVWI protocol that provides similar vessel delineation as fully sampled sequences. Protocol performance was assessed in patients with intracranial atherosclerotic disease and showed clear delineation of vessel wall and atherosclerotic plaque. |
| 2791 | Quantitative 3D Dynamic Contrast Enhanced (DCE) Imaging of Carotid Vessel Wall by Fast T1 Mapping | |
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 |
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Dynamic contrast enhanced (DCE) MRI is a promising technique to quantitatively evaluate the inflammatory status of atherosclerosis noninvasively. However, its demanding sampling requirement leads to sacrifices in slide resolution, coverage, and/or temporal resolution in the applications to vessel wall imaging. In this work we designed accelerated dynamic T1-mapping technique using Low Rank Tensor (LRT) framework to achieve 3D high-resolution quantitative DCE of the carotid arteries. |
| Exhibition Hall | Thursday 8:15 - 10:15 |
| 2792 | Clinical outcomes after magnetic resonance angiography (MRA) compared to computed tomographic angiography (CTA) for pulmonary embolism evaluation | |
1Radiology, University of Wisconsin, Madison, WI, United States, 2Emergency Medicine, University of Wisconsin, United States, 3University of Wisconsin, United States, 4Biostatistics, University of Wisconsin |
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In this retrospective case-control study of 1173 subjects with suspected pulmonary embolism, the 6-month rate of major adverse events (venous thromboembolic, major bleeding, or death) was lower following contrast-enhanced magnetic resonance angiography (MRA) (5.4%) than following computed tomographic angiography (CTA) (13.4%, p < 0.001). The technical success rate of MRA (92.6%) and CTA (90.5%) performed in a routine clinical setting did not differ significantly (p = 0.41). MRA is a clinically effective imaging exam for the primary evaluation of pulmonary embolism. |
| 2793 | Does TWIST with iterative reconstruction improve diagnostics of AVM of the hand? | |
1Institute of Radiology, University Hospital Regensburg, Regensburg, Germany, 2Siemens Healthcare GmbH, Erlangen, Germany |
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Highly accelerated TWIST MRA with standard and iterative reconstruction was compared to a standard TWIST technique in 11 patients with AVM of the hand and/or fingers. Qualitative and quantitative analysis revealed significant advantages for the accelerated protocol with iterative reconstruction: Separation of arterial and venous phase as well as delineation of central and peripheral arterial feeders were significantly improved due to higher temporal resolution compared with our standard protocol while maintaining high spatial resolution. |
| 2794 | Precision and Reproducibility of Cardiac Phase Resolved Ventricular Volumetry using 4D MUSIC MRI in Congenital Heart Disease | |
1Diagnostic Cardiovascular Imaging Laboratory, David Geffen School of Medicien at UCLA, Los Angeles, CA, United States, 2Department of Radiology, David Geffen School of Medicien at UCLA, Los Angeles, CA, United States, 3Department of Medicine, David Geffen School of Medicien at UCLA, Los Angeles, CA, United States |
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Precise and reproducible quantification of ventricular function and volume, particularly right ventricular volumetry, is important in congenital heart disease. Accurate quantification is highly dependent on accurate delineation of myocardial borders. Ferumoxytol-enhanced MUSIC provides multiphase, high resolution, dynamic 3D imaging of the whole heart. We evaluated the precision and reproducibility of ventricular function and volumetric measurements using a commercial 3D image design and modeling software whose segmentation algorithm takes into account partial volume effects (Mimics, Materialise). We demonstrate that quantification of ventricular function and volumetry for 4D MUSIC images using Mimics is reproducible with high intra-class correlation coefficient. |
| 2795 | Quantification of Cerebrovascular Tortuosity of the SCD Patients using Angiography | |
1Division of Cardiology, University of Southern California, Los Angeles, CA, United States, 2Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, 3Cedars-Sinai Medical Center, Los Angeles, CA, United States, 4Radiology, Children's Hospital of Los Angeles, Los Angeles, CA, United States, 5Hematology Oncology, Children's Hospital Los Angeles, Los Angeles, CA, United States, 6Pediatrics and Radiology, Children's Hospital Los Angeles, Los Angeles, CA, United States, 7Neonatology, Children's Hospital Los Angeles, Los Angeles, CA, United States |
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Stroke is a critical complication of Sickle Cell Disease (SCD) and is predicted by increased transcranial Doppler velocities. Recent computational fluid dynamic studies demonstrate a combination of high flow and vessel tortuosity are responsible for high TCD velocities. We determined the predictors of vessel tortuosity in control subjects and SCD patients without known vasculopathy. We applied three different tortuosity metrics (distance measure, inflection count, and sum of angles method) to middle cerebral artery segments measured in 19 SCD patients and 13 controls. Both distance and inflection count metrics were increased in SCD patients but the distance metric was more discriminatory. Age and hemoglobin levels were the strongest predictors of tortuosity in SCD patients. Both terms were retained in multivariate analysis, suggesting that chronic anemia exacerbates the normal increase in vessel tortuosity with age. |
| 2796 | Comparison of Simultaneous Non-Contrast Angiography and intraPlaque Hemorrhage (SNAP) and 3D Time of Flight (TOF) for Non-Contrast Intracranial MR Angiography (MRA) | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, People's Republic of China, 2Department of Radiology, University of Washington |
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The purpose of this study is to compare the MRA image contrast of SNAP and TOF sequences in in-vivo cerebral artery images and explore the explanation of the observation by theoretical simulation. We found TOF MRA showed better artery-background contrast than SNAP MRA in proximal large cerebral artery for all cases, but worse in distal small cerebral artery for most of the cases. The theoretical simulation considering the blood velocity and the blood travel distance in imaging slab further validated this observation, suggesting the contrast difference between SNAP and TOF were related to blood velocity and travel distance. |
| 2797 | Unenhanced Peripheral MRA with Robust Background Suppression using Chemical-Shift-Encoded Single-Slab 3D GRASE: Decomposition of Angiogram and Fatty Backgrounds | |
1Department of Biomedical Engineering, Sungkyunkwan University, Suwon, Korea, Republic of, 2Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, Korea, Republic of |
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Unenhanced peripheral MRA, which is based on cardiac-gated fresh blood imaging, exploits a pulsatile nature of arterial blood flow to differentiate arteries from veins and stationary backgrounds by subtracting two sets of images in cardiac diastole and systole, respectively. However, background signals remain substantial after subtraction due to either varying R-R intervals in between the two cardiac phases or subject motion, potentially obscuring the delineation of angiograms. Under the hypothesis that most of bright background signals result from fatty tissues, we develop a novel, unenhanced peripheral MRA method with robust background suppression using chemical-shift-encoded single-slab 3D GRASE to decompose angiograms and fatty background tissues directly from the subtracted, undersampled k-space data between the dual cardiac phases under the framework of compressed sensing. |
| 2798 | Diagnostic Accuracy Of 3D Head And Neck Joint Black-Blood Vessel Wall Imaging In Patients With Carotid Artery StenosisComparison with DSA | |
1Department of Radiology, Department of Radiology, Anzhen Hospital, CapitalMedical University, Beijing, China, beijing, People's Republic of China, 2Department of Radiology, Anzhen Hospital, CapitalMedical University, Beijing, China, 3Department of Radiology, Anzhen Hospital, CapitalMedical University, Beijing, China, beijing, People's Republic of China |
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Joint head and neck vessel wall imaging technology with variable flip angle turbo spin echo (SPACE)1 has recently been introduced as a promising MRI method for simultaneous evaluation of extra-cranial and intra-cranial vessel wall. However, this technique is yet to be validated with established imaging techniques. We aim to evaluate the accuracy of this technique using DSA as reference in assessing carotid artery stenosis and plaque morphology. |
| 2799 | Coronary MRI allows Assessment and Monitoring of Coronary Patency and Blood Flow Velocity Quantification in Patients treated with Bioresorbable Vascular Scaffolds | |
1Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Freiburg, Germany, 2Department of Cardiology and Angiology I, University Heart Center, Freiburg, Germany |
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Bioresorbable Vascular Scaffolds (BVS) provide a new and rapidly evolving alternative to drug eluting metal stents (DES) in the treatment of coronary artery disease. Besides potential advantages over DES in the restoration of the vessel function and reduction of post-interventional angina BVS allow for artifact-free coronary MRI of scaffolded arteries. In this study, we demonstrate that MRI for non-invasive monitoring of coronary arteries after BVS implantation is feasible by assessing coronary patency in a group of 11 patients initially and one year post-intervention. |
| 2800 | Improving visualization of 4D Flow MRI with four-dimensional angiographic data | |
1Department of Medical and Health Sciences, Division of Cardiovascular Medicine, Linköping University, Linköping, Sweden, 2Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden, 3Department of Clinical Physiology, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden |
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We present a technique for the generation of four-dimensional angiographic data from 4D Flow MRI. Using registration between the timeframes of the 4D Flow MRI, the method concentrates information from the entire cardiac cycle into an angiographic dataset at one timeframe. This step is followed by another set of registrations to generate a time-resolved three-dimensional angiography (4D). Visual comparison of the generated data versus conventional techniques resulted in higher scores in all the regions evaluated. The resulting data allow for visualization of the cardiovascular anatomy throughout the cardiac cycle, facilitating anatomical orientation and enhancing visualization of 4D Flow MRI data. |
| 2801 | Objective Measurement of Carotid Lumen Using Non-Contrast SNAP MRA | |
1Department of Bioengineering, University of Washington, Seattle, WA, United States, 2Department of Radiology, University of Washington, Seattle, WA, United States, 3Department of Surgery, University of Washington |
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Maximum intensity projection (MIP) is a commonly used tool to measure luminal stenosis. MIP images may underestimate stenosis. Directly measuring lumen size represents an alternative solution, but manual segmentation is laborious and sensitive to flow artifacts and bias. Simultaneous non-contrast angiography and intraplaque hemorrhage (SNAP) imaging affords a novel 3D non-contrast MRA approach. The polarity map available with SNAP makes it less sensitive to flow artifacts and facilitates objective lumen boundary definition. In this study, objective lumen measurements on SNAP and 3D-TOF are compared using CE-MRA as a reference. Results showed good agreement between SNAP and CE-MRA on lumen assessment. |
| 2802 | Novel ASL-based flow imaging for cardiovascular hemodynamics and valvular function visualization: comparison with a feasibility study | |
1Department of Radiological services, 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 developed a novel ASL-based flow imaging (ASL-Flow) with modified flow-sensitive alternating inversion recovery technique and Look-Locker sequence to evaluate cardiovascular hemodynamics and valvular dysfunction. We validate that time-intensity curves of pulmonary artery form ASL-Flow matches for time-velocity curves from 2D phase-contrast MRI. ASL-Flow can visualize more clearly regurgitateion and stenotic jet in valvular diseases than standard cine imaging. The scan time for ASL-Flow is short (15 seconds/slice), and the image reconstruction needs no special software; therefore, this is easy to clinically use. We promise that ASL-Flow is a feasible non-contrast imaging to detect hemodynamics abnormality in structural heart disease. |
| 2803 | Transluminal Attenuation Gradient in Non-contrast Whole Heart Magnetic Resonance Coronary Angiography (MRA TAG) – Noninvasive Methods for Assessment of Coronary Flow: A Comparison with Coronary Computed Tomography Angiography TAG | |
1Health Management Center, Toranomon Hospital, Tokyo, Japan, 2Radiology Dept., Toranomon Hospital, Tokyo, Japan, 3Cardiovascular Center, Toranomon Hospital, Tokyo, Japan, 4Imaging Center, Toranomon Hospital, Tokyo, Japan, 5Toshiba Medical Research Institute, Chicago, IL, United States |
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CT coronary angiography (CTA) and non-contrast coronary MRA are established non-invasive methods for anatomical assessment of coronary artery stenosis; however, functional information is limited. Transluminal attenuation gradient (TAG) of CTA predicts a functional significant stenosis. The aim of this study was to access TAG using non-contrast whole heart coronary MRA (MRA TAG) as compared to TAG using CTA (CTA TAG). Preliminary evaluation of MRA TAG provides acceptable prediction of invasive FFR. Further study is required to determine an appropriate prediction of MRA TAG. |
| 2804 | Validation and Error Quantification of Pulmonary Artery 4D Flow-MRI in a digital broadband 3T MR setup | |
1Clinic for Radiology and Nuclear Medicine, University Hospital Schleswig-Holstein, Luebeck, Germany, 2Medical Clinic III: Pulmonology, University Hospital Schleswig-Holstein, Luebeck, Germany |
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4D Flow-MRI offers unique possibilities for the diagnosis of pulmonary hypertension. A validation of the sequence on a digital broadband 3T MR system is essential before introduction into clinical routine. This study compared 4D Flow–MRI derived stroke volume (SV) and maximal flow velocity (Vmax) in the pulmonary arteries of 23 healthy volunteers to 2D phase contrast MRI, right ventricular stroke volume (RVSV), conservation of mass-analysis (COM), and to a static phantom for additional error analysis. Results revealed clinically acceptable differences with a trend of phantom correction to improve results except for the COM-analysis. |
| 2805 | Breath-hold and Free-Breathing Single-Shot Radial Quiescent-Interval Slice-Selective (QISS) MRA for Evaluation of the Pulmonary Arteries | |
1Radiology, NorthShore University HealthSystem, Evanston, IL, United States, 2Radiology, Northwestern University, Chicago, IL, United States, 3Siemens HealthCare, 4Radiology, NorthShore University HealthSystem, 5Radiology, University of Chicago |
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For suspected pulmonary embolism, CTA is the first-line imaging test, with CEMRA a potential alternative. Disadvantages including exposure to ionizing radiation and iodine contrast for CTA, while CEMRA is sensitive to respiratory motion and requires a gadolinium-based contrast agent. As a nonenhanced alternative, we tested breath-hold and free-breathing versions of single-shot radial QISS. Compared with the reference standard, all pulmonary artery branches down to the segmental level were visualized by breath-hold and navigator-gated QISS. With further optimization and validation, radial QISS has the potential to provide a nonenhanced alternative to CTA and CEMRA for the evaluation of suspected pulmonary embolism. |
| 2806 | Improved 3D phase contrast MR angiogram calculation using 3D CINE bSSFP and 4D flow MRI | |
1Department of Radiology, Northwestern University, Chicago, IL, United States, 2Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States, 3Siemens Healthcare, Chicago, IL, United States |
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Improvements in the 3D PC-MRA calculated from 4D flow MRI are needed for better vessel wall depiction and assessment of vascular dimensions. Balanced steady state free precession (bSSFP) is a promising imaging method to combine with 4D flow for an improved depiction of cardiac anatomy and blood-tissue contrast. This study of 10 healthy subjects compares multiple PC-MRA algorithms using bSSFP with 4D flow magnitude and flow images. |
| 2807 | Multi-echo sliding interleaved projection reconstruction (SLIPR) imaging of the carotid artery | |
1Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, United States, 2Siemens Healthcare, Salt Lake City, UT, United States, 3Department of Veterans Affairs (VASLCHCS), Department of Veterans Affairs (VASLCHCS), UT, United States |
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An optimized 3D stack of stars with Sliding Interleaved Projection Reconstruction (SLIPR) provides improved carotid MRA over conventional Time of Flight (TOF) techniques. The stack of stars SLIPR technique takes better advantage of the inflow effect to maximize contrast to noise between blood and tissue. In addition, a multi-echo radial readout minimizes off resonance blurring, allows for fat water separation and shortens acquisition time compared with non-sliding 3D TOF techniques. |
| 2808 | Non-Contrast-Enhanced MRA for Hepatic Vasculature Imaging using Off-Resonance-Robust Velocity-Selective Pulse Train | |
1Philips Healthcare, Shanghai, People's Republic of China, 2Radiology, Johns Hopkins University, Baltimore, United States, 3F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, United States, 4Radiology, Shanghai General Hospital, Shanghai, People's Republic of China, 5Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, People's Republic of China |
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Preoperative hepatic vascular evaluation is of great importance in a variety of liver surgeries, including tumor resection and transplantation. An accurate depiction of hepatic vascular anatomy can help to prevent the complications and decrease the morbidity and mortality in liver surgeries. However, few studies have reported good image quality in hepatic vasculature imaging using non-contrast-enhanced MR angiography (NCE-MRA) because of the motion and complex structure. In recent years, some studies reported the potential of NCE-MRA with velocity-selective pulse train (VSMRA). In this study, we demonstrated the feasibility of VSMRA for imaging the hepatic vasculature with an off-resonance-robust velocity-selective pulse train at 3T. |
| 2809 | A novel method for Background Suppression in Continuous Arterial Spin Labeling (cASL) Angiography | |
1MR Research China, GE Healthcare, Shanghai, People's Republic of China |
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In this work, we implemented background suppression for continuous arterial spin labeling based MR angiography to suppress the noise resulting from the influence of magnetic transfer effect. Pulsed labeling is also incorporated in the background suppression scheme to address the flow void effect in continuous labeling. With the proposed method, the overall vessel clarity was improved without prolonging the scan time. |
| 2810 | The Use of Flip Angle Modulation in Zero TE ASL MRA for Improved Angiogram Quality | |
1MR Research China, GE Healthcare, Shanghai, People's Republic of China, 2Radiology Department, Peking University People's Hospital |
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Time resolved MRA is valuable in study of cerebrovascular disorders. ASL based MRA permits visualization of blood flow without injection of contrast agent. Continuous labeling combined with zero TE readout features maximal labeling efficiency and high angiogram fidelity. However, the constant small flip angle excitation scheme limits its applicability in time resolved visualization. This work performed variable flip angle modulation to improve the quality of angiography in zTE-ASL MRA. |
| 2811 | Can non-contrast Fresh Blood Imaging (FBI) provide sufficient pretreatment information of peripheral artery disease (PAD)? | |
1Department of Radiology, Saiseikai Kumamoto Hospital, Kumamoto, Japan, 2Department of Cardiovascular, Saiseikai Kumamoto Hospital, Kumamoto, Japan, 3Department of Radiology, Kumamoto city Hospital, Kumamoto, Japan, 4Department of Radiology, Tobata Kyoritsu Hospital, Fukuoka, Japan, 5Toshiba Medical Research Institute USA, Japan |
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Diagnostic accuracy of nonenhanced Fresh Blood Imaging (FBI) was compared with digital subtraction angiography (DSA) or digital angiography (DA), which was performed at percutaneous transluminal angioplasty (PTA), in the evaluation of the peripheral lower-extremity arteries. In the evaluation of 173 segments in 25 patients with peripheral arterial occlusive disease, the sensitivity, specificity, and accuracy of FBI of a consensus reading for detection of 50% or greater stenotic lesions were 100%, 83%, and 88%, respectively. FBI achieves high diagnostic accuracy for the detection of peripheral arterial disease (PAD) in comparison with DSA. |
| 2812 | Non-contrast enhanced MR angiography of lower extremity in patients with diabetes: initial experience of using TRANCE technique at 3.0 T | |
1MRI, The 1st affiliated hospital of Henan University of TCM, ZhengZhou, People's Republic of China, 2ShenZhen Institutes of Advanced Technology, People's Republic of China |
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There is a clinical need for implementing a Non-contrast enhanced imaging technique for patients with peripheral arterial disease or diabetes and contraindications for the use of contrast medium, especially patients with decline in kidney function or renal artery stenosis. We optimized TRANCE technique combined with VISTA for best performance of NCE-MRA for lower extremity artery at 3.0T MRI. |
| 2813 | A Novel Technique for 4D Time-of-Flight MR Angiography using Double Adiabatic Inversion Recovery Pulses | |
1Department of Radiology, Tokai University Hospital, Kanagawa, Japan, 2Healthcare department, Philips Electronics Japan, Tokyo, Japan, 3Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan, 4Department of Radiology, Tokai University Hachiouji Hospital, Tokyo, Japan, 5Radiology, Tokai University School of Medicine, Kanagawa, Japan |
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Although previously developed 4D time-of-flight (4D-TOF) at a 3T MR system for evaluating cerebral hemodynamics, this method did not fit at a 1.5T MR system in order to early recovery the brain tissue signals. We proposed a novel 4D-TOF technique using double adiabatic inversion recovery pulse (DIR 4D-TOF) for suppressing background recovery and depiction of intracranial artery at a 1.5T MR system. The results presented show that DIR 4D-TOF with long interval between the first and the second adiabatic inversion recovery pulses could effectively delay T1 recovery of the brain tissue and improved visibility of intracranial artery. |
| 2814 | Optimization of signal-to-noise ratio and signal contrast in time-resolved single-echo Dixon imaging | |
1Mayo Clinic, Rochester, MN, United States, 2Radiology, Mayo Clinic, Rochester, MN, United States |
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Dixon imaging has recently been shown to be useful in contrast-enhanced MR angiography due to motion robustness and improved signal-to-noise ratio. Single-echo Dixon mostly avoids the time penalty associated with multi-echo Dixon imaging, but may incur some time penalty when choosing an echo time to give optimal signal-to-noise ratio (SNR). For dynamic scans, it is beneficial to optimize the imaging parameters for speed, even at the expense of SNR. Additionally, signal contrast can be optimized to further suppress the background water signal. The purpose of this work is to describe optimization of SNR and signal contrast for single-echo Dixon imaging. |
| 2815 | Magnetic resonance imaging discriminates organizing from non-organizing area in deep vein thrombus. | |
1Department of Radiological Technology, Koga General Hospital, Miyazaki, Japan, 2Department of Pathology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan, 3Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 4Department of Radiology, Koga General Hospital, Miyazaki, Japan, 5Department of Internal Medicine, Koga General Hospital, Miyazaki, Japan |
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Deep vein thrombus (DVT) is gradually replaced by fibrous tissue, and is called as organizing reaction. We examined magnetic resonance image (MRI) findings of the organizing DVT in vitro using a 1.5T MR system in autopsy cases with DVT. The organizing area of DVT showed low signal intensity (SI) on T1 weighted images, in contrast to high SI on T1 weighted images in non-organizing area. Both areas showed iso to low SI on T2 weighted image. T1 SI positively correlated with the erythrocyte content in the thrombus. MRI could discriminate organizing from non-organizing area in DVT. |
| 2816 | 3D MR black-blood thrombus imaging for the diagnosis of acute deep vein thrombosis at 1.5 T: a feasibility study | |
1Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China, 2Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, 3Department of Radiology, Guangzhou Panyu Central Hospital |
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Accurate diagnosis of acute deep vein thrombosis (DVT) is relevant for appropriate treatment and avoiding life-threatening events. Recently proposed MR black-blood thrombus imaging (BTI) has demonstrated the potential to provide high sensitive and specific diagnosis of DVT. However, previous studies were performed at 3T and patients investigated were all in subacute to chronic phases. It remains unclear that if BTI could be used for the diagnosis of acute DVT and could work at 1.5T. Therefore, we sought to prospectively assess whether BTI is feasible at 1.5T for diagnosis of acute DVT, using contrast-enhanced MR venography as the standard reference. |
| 2817 | The Diagnostic Value of Sampling Perfection Application with Contrast Optimized Using Variable Flip Angle Evolutions (SPACE MR) in Evaluating Lower Extremity Deep Venous Thrombus | |
1Radiology Department, Tongji Hospital, Wuhan, People's Republic of China, 2MR Collaboration NE Asia, Siemens Healthcare, Shanghai, People's Republic of China, 3Siemens healthcare NEA, MR Scientific Marketing, Guangzhou, People's Republic of China |
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The study evaluate the diagnostic performance of SPACE MR sequence in detecting lower extremity deep venous thrombosis (DVT) and evaluating clot burden, with comparison to ultrasound (US). The result showed that SPACE MR is highly accurate in detecting lower extremity DVT and reliable in the evaluation of clot burden, thus could be considered as an important alternative for patients in whom US cannot be performed. |
| 2818 | Clinical utility of the pulmonary artery to ascending aortic ratio by cardiac magnetic resonance in patients with pulmonary hypertension. | |
1Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan, 2Nuclear Medicine, Hokkaido University Hospital, 3First Department of Medicine, Hokkaido University Hospital, 4Department of Cardiovascular Medicine, Hokkaido University Hospital |
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Thirty-three patients with pulmonary hypertension (PH) and age-, sex-matched 15 controls were retrospectively evaluated. The pulmonary artery to ascending aortic ratio (PA-A ratio) measured by cardiac MRI was significantly higher in PH patients than that in controls. The patients with pulmonary arterial hypertension showed a significantly higher PA-A ratio compared to patients with other causes of PH. Increased PA-A ratio showed significant correlations with right ventricular (RV) dilatation and decreased RVEF. The PA-A ratio showed high sensitivity and specificity for detection of PH. The PA-A ratio using cardiac MRI is an easy surrogate marker for detection of RV dysfunction and PH. |
| 2819 | Estimation of Circulating Blood Volume using Ferumoxytol | |
1National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States |
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Clinical assessment of total blood volume is significant for management of patients with decompensated chronic heart failure. We investigate the feasibility of measuring circulating blood volume as part of an interventional cardiovascular MR exam by measuring T1 changes due to the presence of Ferumoxytol - an intravascular, FDA-approved, iron supplement. Three pigs were scanned prior and twenty minutes post Ferumoxytol administration, from which a mean blood volume of 81.6 ± 1.1 mL/kg was estimated, which approximately overestimates by 15-30% from the literature. This technique has promise as a non-ionizing and non-toxic alternative to measuring patient volume. |
| 2820 | Visibility of the draining location of the thoracic duct to the venous system on balanced turbo field echo with extended k-space sampling | |
1Radiology, Tokai University School of Medicine, Isehara, Japan, 2Radiology, Tokai University Hospital, Isehara, Japan |
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The knowledge regarding the visibility of the thoracic duct draining to the venous system has remained sparse. We assessed the visibility of draining location of the thoracic duct to the venous system in the subclavian region using balanced turbo field echo (bTFE) with extended k-space sampling. As a result, a relatively good visibility was achieved in the thoracic duct and the venous branches in the region. This sequence may be useful to grasp the draining location of the thoracic duct to the venous system at the subclavian region. |
| 2821 | Evaluation of Pediatric Tracheobronchial Anomalies with congenital heart disease using Three-dimensional Turbo Field Echo Magnetic Resonance Imaging Sequence | |
1Radiology, Shanghai Children’s Medical Center affiliated with Shanghai Jiao Tong University school of medicine, Shanghai, People's Republic of China |
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Tracheobronchial anomalies are common in congenital heart disease (CHD). Cardiovascular anomaly is the principal extrinsic lesion causing tracheobronchial stenosis. MSCT remains an ionizing procedure even though can demonstrate tracheobronchial tree clearly. MRI has the advantage of being non-ionizing and providing excellent soft tissue contrast for the diagnosis of CHD and tracheobronchial anomalies. Spin echo (SE) sequence can demonstrate the tracheobronchial tree but this typically a 2D sequence and therefore difficult to depict the entire tracheobronchial tree optimally. Three-dimensional turbo field echo (3D-TFE) can delineate the entire tracheobronchial tree clearly through post-processing. |
| 2822 | Direct and Indirect Findings of Pulmonary Embolism Using Contrast Enhanced Magnetic Resonance Angiography (CE-MRA) | |
1Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 3Department of Pediatrics, University of Wisconsin-Madison, Madison, WI, United States, 4Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States, 5Department of Emergency Medicine, University of Wisconsin-Madison, Madison, WI, United States, 6Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States |
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Contrast enhanced pulmonary MRA is an important modality for detecting PE in those situations where there are concerns about excess exposure to ionizing radiation or contraindications to iodinated contrast. While most radiologists are experienced in interpreting CT angiographic studies for pulmonary embolus, many are unfamiliar with CE-MRA for the diagnosis of PE. It is important for interpreting physicians to understand both the direct and indirect findings associated with PE. In our retrospective study of 682 patients, we found 136 PE in 61 patients. The prevalence of both direct and indirect findings associated with PE were reviewed in this study. |
| 2823 | Cardiac manifestations of diffuse lung disease: A pictorial review of cardiac magnetic resonance imaging findings | |
1Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, 3Department of Pediatrics, University of Wisconsin-Madison, Madison, WI, United States |
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Many disease processes associated with diffuse lung disease also have cardiac abnormalities. These cardiac abnormalities can easily be overlooked if one focuses too heavily on the lung findings. The purpose of this educational exhibit is to review the characteristic imaging findings associated with the cardiac manifestations of diffuse lung disease. |
| Exhibition Hall | Thursday 8:15 - 10:15 |
| 2824 | Voxel-by-Voxel 4D Flow Based Assessment of Retrograde Flow in the Aorta | |
1Biomedical Engineering, Northwestern University, Chicago, IL, United States, 2Radiology, Northwestern University, Chicago, IL, United States |
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Retrograde fraction stratifies the degree of aortic regurgitation (AR) in patients with aortic valve disease. The purpose of this study was to develop 4D flow based voxel-by-voxel regional analysis of forward flow, reverse flow, and retrograde fraction with full volumetric coverage of the aorta. In a study with 10 subjects (5 healthy controls, 5 patients with AR), reverse flow and retrograde fraction maps were used to systematically analyze regional flow patterns and assess differences between standard (plane-wise) and voxel-by-voxel quantification of AR. |
| 2825 | Temporal variation of cerebrovascular transit time measured by BOLD-based time lag mapping | |
1Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto, Japan |
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A pilot study of perfusion-related signal component in fMRI signal, demonstrates possibility of measuring blood transit time variation by tracking BOLD lag through the vascular structure. Effect of short breath-holding and mild hyperventilation on the time-shift analysis of whole-brain BOLD signals were tested. Temporal variation of the relative BOLD transit time up to ±15% on average were found to be negatively correlated with the global BOLD signal change, which is consistent with the Central Volume Principle under the condition of small CBV change. This relative BOLD transit time is likely to reflect the global CBF/CBV dynamics with high temporal resolution. |
| 2826 | An automatic method to estimate 3D Pulse Wave Velocity from 4D-flow MRI data | |
1Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, Chile, 2Department of Biomedical Engineering, King's College London, London, United Kingdom, 3Department of Electrical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile, 4Department of Radiology, School of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile |
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One of the most common and well-accepted biomarkers for Cardiovascular diseases is the Pulse Wave Velocity (PWV), related with the time-shift observed in pressure or flow waveforms along the artery. Some drawbacks in its application can be summarized as data often collected by catheterization or separated 2D flow planes, centerlines do not necessarily coincide with the path followed by wavefronts and, the methods are user-dependent. We propose a novel method for PWV avoiding centerlines by evaluating flows over wavefronts to improve results. A systematic analysis of phantom scans and to a set of volunteers and patients show promising results. |
| 2827 | Phase-Contrast MRI with Hybrid One- and Two-sided Flow-Encodings and Velocity Spectrum De-aliasing (HOTDEAL) using Low Spatial Resolution Reference Four-point Phase-Contrast MRI | |
1Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States, 2Biomedical Physics Interdepartmental Graduate Program, University of California, Los Angeles, Los Angeles, CA, United States, 3Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States |
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The proposed technique, phase-contrast MRI (PC-MRI) technique with hybrid one- and two-sided flow-encoding and velocity spectrum de-aliasing (HOTDEAL) using low spatial resolution reference four-point PC-MRI for accelerated blood flow and velocity measurement, is a novel M1-space (gradient first moment space) under-sampling technique for accurate Fourier velocity spectra separation. |
| 2828 | Evaluate Systolic and Diastolic Wall Shear Stress of Aorta for Marfan Syndrome by 4D Flow MRI | |
1Institute of Systems Neuroscience, Hsinchu, Taiwan, 2Department of Pediatrics, Taipei, Taiwan, 3Institute of Medical Device and Imaging, Taipei, Taiwan, 4Department of Biomedical Engineering and Environmental Sciences, Hsinchu, Taiwan |
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We aim to reveal the abnormality of plane-wise and segmental WSS in different cardiac phases of patients with Marfan syndrome (MFS) with dilated aorta. MFS group presented lower plane-wise axial WSS than normal group at ascending aorta and descending aorta during systole. In respect of segmental WSS, either in the whole cardiac cycle or during systole, MFS patients demonstrated reduced values at almost all segments in proximal ascending aorta. In conclusion, the quantitative indices of plane-wise and regional WSS clearly differentiate MFS patients from normal controls. Therefore, quantification of WSS can provide promising approaches for patient managements in the future. |
| 2829 | Independent phantom validation of Metric Optimized Gating for fetal cardiovascular phase-contrast flow imaging and application in a second center | |
1Clinical Sciences Lund, Clinical Physiology, Lund University, Skane University Hospital, Lund, Sweden, 2Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden, 3Diagnostic Radiology, Lund University, Skane University Hospital, Lund, Sweden, 4Laboratory of Computing and Medical Informatics, Aristotle University, School of Medicine, Thessaloniki, Greece |
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Fetal cardiovascular MRI may enhance clinical flow measurements. The lack of fetal ECG for gating however makes phase contrast (PC) flow quantification challenging. Metric Optimized Gating (MOG) overcomes this limitation, but is currently applied only in a single center. We provide independent pulsatile-flow phantom validation of MOG PC-MRI for fetal flow volumes and heart rates, and measurements in human fetuses in a second center. Flow by MOG agrees with timer/beaker and gated flow quantification, and gives pulsatile fetal flow curves in a second center, suggesting MOG PC-MRI as a reliable tool for fetal flow quantification in more centers. |
| 2830 | A novel platform to study hemodynamics and morphology in an ex vivo carotid artery model under pulsatile flow conditions | |
1Medizinische Klinik und Poliklinik I, Universitätsklinikum Würzburg, Würzburg, Germany, 2Experimentelle Physik V, Universität Würzburg, Würzburg, Germany, 3Institut für Diagnostische und Interventionelle Neuroradiologie, Universitätsklinikum Würzburg, Würzburg, Germany, 4Deptartment of Tissue Engineering and Regenerative Medicine, Universitätsklinikum Würzburg, Würzburg, Germany, 5Fraunhofer IIS, Fraunhofer EZRT, Magnetresonanz- und Röntgenbildgebung (MRB), Würzburg, Germany |
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Biological artery models, cultured in a bioreactor-platform with adjustable pulsatile flow conditions, represent a potential in vitro test system for atherosclerosis research and provide a suitable tool for the development of new flow quantification techniques as well as studies of arterial elasticity and flow dynamics ex vivo and in vitro. A major requirement for these studies is viable motion synchronization in order to achieve time-resolved flow measurements. We present a new platform that uses self-navigation instead of external trigger signals for measurements of 2D- and 4D flow dynamics, vessel wall morphology and quantifications of arterial pulse-wave-velocity and wall shear stress. |
| 2831 | Distribution of 4D flow MRI-derived wall shear stress and oscillatory shear index and its relation with the ascending aorta dilation in bicuspid valve patients. | |
1Hospital Universitari Vall d´Hebron, Department of Cardiology. Vall d’Hebron Institut de Recerca (VHIR). Universitat Autònoma de Barcelona. Barcelona. Spain, barcelona, Spain, 2Hospital Universitari Vall d´Hebron, Department of Cardiology. Vall d’Hebron Institut de Recerca (VHIR). Universitat Autònoma de Barcelona. Barcelona. Spain, 3Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Department of Electrical Engineering, Pontificia Universidad Católica de Chile, 4Department of Structural and Geotechnical Engineering, Pontificia Universidad Católica de Chile, 5Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Department of Electrical Engineering, Pontificia Universidad Católica de Chile. |
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Elevated WSS is atheroprotective but implies greater medial degradation. Lower WSS degenerates endothelium and determines aneurysm area with lower dilation and rupture risk. OSI distinguishes aneurysm for rupture. Through 4D-flow MRI we analyze WSS and OSI ascending aortic regional differences in 27 BAV patients and 11 controls. Despite average WSS and OSI do not different among TAV and BAV, RL-BAV and RN-BAV and dilated and non-dilated BAV, regional differences have been found. Of most interest, dilated BAVs have partially overlapping regions of lower WSS and high OSI in the distal-anterior ascending aorta which may explain ascending aorta dilation morphotype |
| 2832 | The feasibility of correcting for through-plane heart motion on phase contrast aortic blood flow measurements using feature tracking cine-MRI | |
1Dept of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden, Sahlgrenska University Hospital, Gothenburg, Sweden, 2Dept. of Medical Physics and Techniques, Sahlgrenska University Hospital, Gothenburg, Sweden, Sahlgrenska University Hospital, Gothenburg, Sweden, 3Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden, 4Dept of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden, Sahlgrenska University Hospital |
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Phase contrast measurements are prone to velocity offsets due to through-plane motion of the heart. Here we present a promising method for correction of through-plane heart motion on phase contrast aortic blood flow measurements. The method, which utilizes the inherent information in conventional cine MR images for tracking of the aortic valve, was shown to be both robust and accurate. The reliability, but also the availability of the method makes it an attractive tool for correction of velocity offsets due to through-plane heart motion. |
| 2833 | 4D Flow MRI and lumped parameter modelling for subject-specific assessment of cardiovascular function | |
1Division of Cardiovascular Medicine, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden, 2Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden, 3Department of Medicine, University of California San Francisco, San Francisco, CA, United States, 4Department of Clinical Physiology, Department of Medical and Health Sciences, Linköping University, Linköping, Sweden, 5Division of Applied Thermodynamics and Fluid Mechanics, Department of Management and Engineering, Linköping University, Linköping, Sweden |
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Lumped-parameter models of the cardiovascular system can improve the understanding of cardiovascular function and assist treatment planning. The clinical applicability of these models improves when they are subject-specific. This work proposes an approach to personalizing a model of the heart and the systemic circulation using exclusively non-invasive measurements from routine cardiovascular MRI and 4D Flow MRI. Personalized models were constructed for eight healthy volunteers. The model-based pressures and flows agreed well with the in-vivo measurements for each subject. The proposed approach can be used to synthesize medical data into clinically relevant information and estimate parameters that cannot be measured clinically. |
| 2834 | Evaluation of Aortic Hemodynamics in Patients with Sievers Type II BAV | |
1Radiology, Northwestern University, Chicago, IL, United States, 2Radiology, Lurie Children's Hospital, Chicago, IL, United States, 3Biomedical Engineering, Northwestern University, Chicago, IL, United States |
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Sievers type II bicuspid aortic valve (BAV) is a rare disease that has been associated with more severe aortopathy than the more common type I BAV. To study the relation between aortic valve (AV) morphology and altered aortic hemodynamics in this disease, 4D flow MRI data from 32 type II BAV patients with different AV fusion types were analyzed. The helicity direction of blood flow in the ascending aorta was found to be influenced by AV morphology. Additional research with a larger cohort and comparison to type I BAV should render further insights into the pathophysiologic mechanism underlying BAV aortopathy. |
| 2835 | Peak ventricular transit time with first pass perfusion on cardiac MRI is a new marker of right ventricular dysfunction and pulmonary hypertension | |
1Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan, 2Nuclear Medicine, Hokkaido University Hospital, 3First Department of Medicine, Hokkaido University Hospital, 4Department of Cardiovascular Medicine, Hokkaido University Hospital |
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Thirty-three patients with pulmonary hypertension (PH) and 16 controls were retrospectively evaluated. The right-to-left peak ventricular transit time (PVTT) determined using cardiac first-pass perfusion MRI was prolonged in patients with PH without left ventricular dysfunction. The degree of PVTT prolongation showed a modest association with right ventricular dilatation and dysfunction. Significant positive correlations were observed between PVTT and pulmonary artery pressures. The PVTT showed moderate sensitivity (65%) and high specificity (90%) for detection of PH. PVTT may be an additional simple tool to evaluate right ventricular dysfunction and pulmonary artery pressure in patients with PH. |
| 2836 | Quantification of helical flow and aortic tortuosity using 4D Flow MRI | |
1Department of Medical and Health Sciences, Linköping University, Linköping, Sweden, 2Center for Medical Image Science and Visualization (CMIV), Linköping, Sweden, 3University Hospital Linköping, Linköping, Sweden |
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Due to the complex anatomy of the heart, its valves, and the aorta, the blood flow in the aorta is similarly complex and can exhibit a swirling, or helical flow pattern. Previous studies have shown that aortic geometry changes with age. As the shape of the aorta is complex and evolves over time, the aim of this study is to examine the relationship between the shape of the aorta and helical flow. The results show that the aorta gets more tortuous with age, and that the increased tortuosity is associated with increased helicity. |
| 2837 | Magnetic Resonance Imaging Reveals Elevated Aortic Pulse Wave Velocity in Overweight Adolescents | |
1Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, ON, Canada, 2Department of Exercise Sciences, University of Toronto, Toronto, ON, Canada, 3Faculty of Kinesiology and Physical Education, University of Toronto, ON, Canada, 4Labatt Family Heart Centre, Hospital for Sick Children, Toronto, ON, Canada, 5Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada, 6Department of Pediatrics, Faculty of Medicine, University of Toronto, Toronto, ON, Canada |
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This study provides a comparison of four commonly-used estimates of PWV to evaluate aortic stiffness, and compares these estimates of PWV with factors indicating cardiometabolic risk in obese youth. Hemodynamic parameters and phase-contrast CMR of the aortic arch at 3.0T were measured in 19 participants (12 obese, 7 normal-weight). Four methods of estimating PWV were used (cross-correlation, foot-to-foot, half-peak, area under the curve). There was an association between increasing measures of inflammation (C-reactive protein) and BMI, indicating that aortic PWV may be associated with changes in arterial stiffness in adolescents with subclinical biomarkers of cardiovascular disease. Careful consideration should be given to the method of PWV estimation due to measurement bias. |
| 2838 | Comprehensive Noninvasive Hemodynamics Using High Temporal Resolution Phase Contrast MR Imaging | |
1Centre for Cardiovascular Imaging, University College London, London, United Kingdom, 2Adult Congenital Heart Disease Department, St Bartholomew’s Hospital, London, United Kingdom, 3IBiTech-bioMMeda, iMinds Medical IT, Ghent University, Gent, Belgium |
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Implementation of an imaging based technique to perform a non-invasive, comprehensive hemodynamic assessment, using high temporal resolution phase contrast imaging. |
| 2839 | Influence of the k-t Principal Component Analysis acceleration factor on the accuracy of flow measurement in 4D PC-MRI | |
1BioFlow Image, University of Picardie Jules Verne, Amiens, France, 2Maxillo-facial surgery, University Hospital of Amiens, Amiens, FL, France, Metropolitan, 3Biomechanics & Bioengineering Laboratory, Université de Technologie de Compiègne, Compiègne, France, Metropolitan, 4Department of image processing, University Hospital of Amiens, Amiens, France, Metropolitan |
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The main purpose of this phantom study is to assess the influence of k-t Principal Component Analysis reconstruction technique on the 4D PC-MRI velocity measurements through millimetrics vessels. 4D PC-MRI sequence is repeated 4 times with a k-t PCA acceleration factor set at 0, 2, 4 and 8. Flow curves are reconstructed and their mean flow and amplitude are compared. Results shows it is possible to reduce the acquisition time and still maintain a good mean flow measurement accuracy. However, the k-t PCA acceleration factor causes loss of information, resulting in a decrease of the amplitude of the flow curve. |
| 2840 | Assessment of global cerebral flow: comparing 2D and 4D flow strategies | |
1Lund University Bioimaging Center, Lund University, Lund, Sweden, 2Dept. of Medical Radiation Physics, Lund University, Lund, Sweden, 3Lund University, Dept. of Clinical Sciences Lund, Clinical Physiology, Skane University Hospital, Lund, Sweden, 4Dept. of Diagnostic Radiology, Lund University, Lund, Sweden |
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Quantifying the total blood supply to the brain and relating that to brain tissue mass gives a measure of global cerebral blood flow (CBFglo). The cerebral blood flow can be measured using phase contrast MRI in the supplying arteries. For accuracy, separate 2D flow measurements for each vessel has been recommended. An alternative is to use one 4D flow measurement that covers all vessels of interest and allows flexible definition of measurement planes. The aim of this work is to compare the flow results obtained from a single 2D flow measurement to those from a 4D flow scan. |
| 2841 | Real-time monitoring of Exercise Stress using Spiral Flow MRI | |
1National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States |
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Interventional cardiovascular MR exams can augment catheter procedures with simultaneous functional measurements. This preliminary work implements an accelerated spiral acquisition to measure real-time, beat-to-beat cardiac output changes during exercise stress induced using a MR-compatible ergometer. At rest, the beat-to-beat variation in cardiac output had a coefficient of variation of 19.1 ± 16.8%. Using this high temporal resolution sequence, a significant increase in cardiac output (5.23 L/min to 8.39 L/min) was measured between rest and exercise sustained at 160-180 W. |
| 2842 | Improved Visualization of Common Iliac Artery 3D-cine Phase Contrast Magnetic Resonance Imaging Using Selective Water Excitation | |
1Department of Radiological Technology, Kurashiki Central Hospital, Okayama, Japan, 2Philips Electronics Japan, Tokyo, Japan, 3Department of Medical Technology, Kurashiki Central Hospital, Okayama, Japan |
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The motion artifacts in the pelvic area using 3D-cine phase contrast (4D PC) MRI may be provide the severity results. The purpose of this study was to demonstrate the usefulness of fat suppression for the common iliac artery (CIA). The study protocol compared 4D PC MRI date without fat suppression to with principle of selective excitation technique (ProSet). We evaluated the streamline visualization, SNR of magnitude images and blood flow volume. ProSet can reduce respiration artifacts. Extending of TR by using ProSet increases SNR. Thus ProSet1-1 is the optimal fat suppression technique to improve vascular visualization. |
| 2843 | Comprehensive Hemodynamics of Living Donor Liver Transplantion Using MRI-based In-Vitro Experiments and Computational Simulation | |
1Mechanical Engineering, UW Madison, Madison, WI, United States, 2Radiology, UW Madison, Madison, WI, United States, 3Medical Physics, UW Madison, Madison, WI, United States, 4Biomedical Engineering, UW Madison, Madison, WI, United States, 5Medicine, UW Madison, Madison, WI, United States, 6Emergency Medicine, UW Madison, Madison, WI, United States |
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The purpose of this study was to develop a patient specific experimental methodology to complement computational surgical planning models for living donor liver transplant. 4D flow MRI was performed on one healthy liver donor before and after partial hepatectomy. Physical models of the donor vasculature were created, and experiments were conducted to measure flow and pressure throughout the system. Experimental results were compared with 4D flow measurements and simulation results. Flow measurements were significantly similar between imaging and simulation, and between simulation and experiment. This methodology will be used to improve boundary value assumptions in surgical planning models. |
| 2844 | An outlier rejection scheme to improve background phase correction in PC-MRI | |
1The Ohio State University, Columbus, OH, United States, 2Siemens Healthineers, 3The Ohio State University |
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The accuracy of flow quantification in phase contrast MRI (PC-MRI) is limited by the presence of eddy current-induced background phase. A widely reported method to correct background phase relies on polynomial fitting of the pixels within regions of static tissue. However, separating regions with steady flow from static tissue can be challenging because such regions lack temporal variations that are often used to identify and eliminate pixels that are not static. In this work, we present and validate a processing method that identifies and eliminates outliers such as pixels belonging to venous flow and thus improves flow quantification. |
| 2845 | Improving Non-Contrast 4D Flow MRI Using Multiple-Thin-Slab Dual-Venc Acquisition | |
1Technical University of Munich, Munich, Germany, 2GE Healthcare, CA, United States, 3GE Global Research, Munich, Germany, 4MRI Research Center, University Children Hospital, Zurich, Switzerland |
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Dual-venc 4D flow MRI can improve velocity-to-noise ratio (VNR) using a low-venc velocity map to provide a good VNR and a high-venc velocity map to correct the velocity aliasing. However, dual-venc 4D flow MRI significantly lengthens the scan duration to longer than the 10min delayed enhancement wait time and therefore it is difficult to take advantage of T1 shortening immediately after contrast injection. On the other hand, whole volume acquisition saturates blood signal and decreases SNR for 4D flow MRI, especially without contrast agent. Multi Thin Slab (MSLAB) 4D flow MRI acquisition technique provides bright blood imaging with improved SNR and motion robustness. Therefore, by combining dual-venc with MSLAB we propose a more accurate 4D flow method without requirement of contrast agent. In this study, we analyzed our proposed method in a pulsatile flow phantom in terms of VNR and performance in a volunteer. |
| 2846 | Volumetric Segmentation-Free Method for Quantitative Visualization of Cardiovascular Wall Shear Stress Using 4D Flow MRI | |
1University of California, San Diego, La Jolla, CA, United States, 2Stanford University, Stanford, CA, United States |
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We demonstrate a volumetric technique for calculation and visualization of great vessel wall shear stress (WSS) from 4D Flow MRI data. Traditional methods for WSS have relied on planar sections of the data followed by explicit manual segmentation of vessel boundaries, which can be labor-intensive to perform. We propose a volumetric strategy for computation and visualization of WSS, which may facilitate its clinical translation. |
| 2847 | Feasibility of non-contrast-enhanced cardiovascular 4D flow MRI using a balanced SSFP approach | |
1Department of Electrical Engineering, Stanford University, Stanford, CA, United States, 2Department of Radiology, Stanford University, CA, United States |
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Balanced steady state free precession (bSSFP) phase-contrast sequences have desirable tissue contrast properties that allow for non-contrast-enhanced cardiovascular flow exams. However, they are susceptible to flow-related signal dephasing especially in regions with highly accelerating flow like the heart. To address this, we propose a variable-density radial view-ordered bSSFP 4D flow sequence. Acquired images show reasonable visualization of cardiac anatomy, and similar velocity measurements in aortic regions. Further sequence modifications are suggested to improve its robustness. If proven to be a viable alternative to the standard exam, bSSFP 4D flow would reduce exam costs and greatly improve patient experience. |
| 2848 | Evaluation of three-dimensional flow characteristics behind the prosthetic mechanical valve under subvalvular pannus formation; in-vitro 4D flow MRI | |
1Mechanical Engineering, POSTECH, Pohang, Korea, Republic of, 2Department of Convergence Medicine, Asan Medical Center, 3Department of Radiology, Asan Medical Center |
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A pannus formation is a growth of abnormal tissues around the heart valve, which is often found in patients whom underwent heart valve replacement surgery. Significant hemodynamic changes caused by the formation of the pannus may contribute to the failure of the valves even without direct contact to the leaflets. In current study, flow in the sinus if Valsalva under subvalvular pannus formation was analyzed using in vitro phantom and 4D flow MRI. Symmetric pannus causes imperfect opening the valve, which might lead to the heart failure. |
| 2849 | Quantification of cerebrospinal fluid flow through the cerebral aqueduct using 7T MRI | |
1Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, 2Spinoza Center for Neuroimaging, Amsterdam, Netherlands, 3Department of Radiology, Vanderbilt University Medical Center, Nashville, TN, United States |
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In this work the feasibility of recording high spatial resolution quantitative flow (Qflow) measurements in the cerebral aqueduct at 7T was investigated. Five volunteers were scanned, two encoding velocities (venc) were used: 5 and 13 cm/s. Repeated measurements were performed (venc=5cm/s: n=4; venc=13 cm/s: n=5). Mean net CSF flow through the aqueduct (directed towards the spine) was (mean±std) 332±128 ml/day for venc=5cm/s and 441±149 ml/day for venc=13cm/s, which is in accordance with values found in literature. Reasonable reproducibility of the measurements was found. |
| 2850 | The Magnitude of Static Phantom Corrections for Velocity Encoded Phase Contrast Cine MRI and Clinical Importance | |
1National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States, 2Physiology Department, Northwestern University, Chicago, IL, United States, 3Computational Neuroscience, IBM / Thomas J Watson Center, Yorktown Heights, NY, 4Cardiology and Radiology, Hofstra Northwell School of Medicine, Manhasset, NY, United States |
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The purpose of this study was to investigate the magnitude of ex vivo static phantom corrections affecting Qp, Qs, and the Qp-to-Qs ratio measurements in diagnosing patients with intracardiac shunts. In the patients with Cath as the reference standard, phantom correction improved both the bias as well as the limits of agreement for Qp and the Qp:Qs ratio. For Qs, phantom correction improved the bias but did not significantly change the limits of agreement. While phantom correction appears to improve phase contrast MRI measurements, the main benefit is limited to patients with Qp:Qs close to the important diagnostic threshold selected. |
| 2851 | Image-based Background Phase Error Correction in 4D Flow MRI | |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Department of Radiology, University Hospital Cologne, 3Division of Imaging Science and Biomedical Engineering, King’s College London |
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Background phase errors occurring in 4D Flow MRI are analyzed with respect to their spatial order. Results demonstrate that background errors can range from first up to third spatial order requiring correction with appropriate polynomial orders. While higher order corrections perform well even for low SNR, they are highly sensitive to the amount of stationary tissue present for background phase estimation requiring at least 25%, 60% and 75% of stationary tissue for systems with first, second and third order offsets The amount of stationary tissue available in-vivo, however, limits the use of higher order polynomial models for background phase correction. |
| 2852 | 4D flow MR measurements for functional assessment of idiopathic pulmonary arterial hypertension: comparison between patients and healthy volunteers | |
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, People's Republic of China, 2Department of MR, Beijing Shijitan Hospital of Capital Medical University, 3Department of Pulmonary Vascular Disease and Geriatric Medicine, Beijing Shijitan Hospital of Capital Medical University |
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We applied parameter analysis in 4D flow imaging for pulmonary artery hypertension (PAH) and compare the MR parameters between five patients with iPAH and five healthy volunteers. Compared with healthy volunteers, patients with idiopathic PAH have more retrograde flow in MPA, enlarger area of MPA, higher peak acceleration. And Plane-to-plane variations of these parameters were evaluated using the Bland-Altman comparisons, some parameters have relatively low variations which means they can be calculated through 2D flow imaging. In conclusion, MRI results show that the effect of increased pulmonary artery pressure and resistance has influence the flow in MPA. |
| 2853 | Phase Contrast MRI with Automatic Inline Second Order Background Phase Correction | |
1Cardiovascular MR R&D, Siemens Healthineers, Chicago, IL, United States, 2Pediatric Cardiology, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA, United States, 3Cardiovascular Imaging Research Core, Children's Healthcare of Atlanta, Atlanta, GA, United States, 4Medical Imaging Technologies, Siemens Medical Solutions USA, Inc., Princeton, NJ, United States, 5Cardiovascular MR R&D, Siemens Healthineers, Erlangen, Germany |
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This work presents an automatic inline method for correction of background phase errors in 2D PC MRI. Flow images were automatically processed during image reconstruction for background phase correction. Uncorrected and corrected images were compared qualitatively and quantitatively. Quantitative flow measurements were performed by two experienced observers using a fully-manual method and a semi-automated method. Mean Qp/Qs of the patient cohort was used as a metric to evaluate the proposed second order background phase correction method. |
| 2854 | 4D-flow-MRI in patients with Fontan circulation for evaluation of pulmonary artery blood distribution | |
1Department of Radiology, University of Munich, Munich, Germany, 2University of Wisconsin - Madison, Madison, United States, 3DZHK German Center for Cardiovascular Research, Munich, Germany, 4Department of Pediatric Cardiology and Pediatric Intensive Care, University of Munich, Munich, Germany |
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4D-flow-MRI can serve as a non-invasive imaging modality to monitor patients with congenital heart disease and status post surgical repair. Patients with Fontan-circulation need to be followed up regularly to identify the right time for re-intervention to avoid pulmonary hypertension or atrophy due to hyper- or hypoperfusion, respectively and the development of protein-losing enteropathy. |
| 2855 | 4D-Flow enables depictions and quantitative analysis of the characteristic flow fluctuations in the infrarenal aorta and diastolic suction flow in renal arteries | |
1Radiology, Hamamatsu University School of Medicine, Hamamatsu, Japan, 2Department of Fundamental Development for Advanced Low Invasive Diagnostic Imaging, Nagoya University, Nagoya, Japan, 3Radiology, Stanford University School of Medicine, Palo Alto, CA, United States, 4Applied Science Laboratory Asia Pacific, GE Healthcare Japan, Hino, Japan |
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4D-Flow can be used to visually and quantitatively evaluate characteristic retrograde flow within the infrarenal abdominal aorta and the diastolic suction flow within the RAs, which might be the initiation factor of degradation of abdominal aortic wall followed by fatal aortic disease. |
| 2856 | MRI-based Fluid Structure Interaction Simulation of the Bicuspid Aortic Valve using Native Non-linear Valve Properties | |
1Radiology, Northwestern University, Chicago, IL, United States, 2Saint Anthony Falls Laboratory, University of Minnesota Minneapolis, MN, United States, 3Department of Civil,Environmental and Geo-engineering, University of Minnesota Minneapolis, 4Stony Brook University |
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Limitations of temporal and spatial resolution prevent MRI from visualizing boundary layers and fluid structure interaction (FSI) occurring immediately adjacent to the valve leaflets as well as at the aortic wall downstream from the valve. We make use of CMR image-based patient specific anatomy and boundary conditions to perform computational fluid dynamic (CFD) analysis which incorporates moving boundary conditions. The numerical approach is shown to elucidate complex and dynamic blood and leaflet behavior previously not seen with CMR alone. |
| 2857 | Analysis of WSS variability subjected to changes of 4D flow parameters using a realistic aortic phantom. | |
1Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Santiago, Chile, 2Electrical Engineering Department, Pontificia Universidad Católica de Chile, Santiago, Chile, 3Radiology Department, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile, 4Hospital Virgen del Rocio, Universidad de Sevilla, Seville, Spain, 5Institute of Biomedicine of Seville, Universidad de Sevilla, Seville, Spain |
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The purpose of this work was to study the accuracy of the estimation of WSS calculated from 4D flow data acquired at different spatial and temporal resolutions. The data was acquired using a realistic thoracic aortic phantom in nine different hemodynamic conditions. We conclude that WSS measurements are more sensitive to changes in spatial resolution than in temporal resolution. |
| 2858 | Left Ventricle Strain Estimation using flow MRI | |
1Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Santiago, Chile, 2Department of Electrical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, 3Department of Radiology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile |
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The stiffness in the myocardium represents a reliable biomarker of cardiac dysfunction or diseases, such as atherosclerosis or cardiac infarction. Actually, there exist methods to retrieve this indicator using MRI, however, they can be very time-consuming, especially for volumetric evaluations. In this work, we propose a novel method to estimate strains using Phase-Contrast or 4D-flow data, where velocity fields are transformed into strain tensors in a numerically simple but robust manner. Preliminary results are promising and we expect to validate our method in volunteers and patients. |
| 2859 | Quantification of blood flow in the great veins and right heart using 4D flow MRI in Chronic Obstructive Pulmonary Disease: A pilot study in the MESA COPD Study | |
1Department of Radiology, Northwestern University, Chicago, IL, United States, 2Radiology, Northwestern University, Chicago, IL, United States, 3Epidemiology, Columbia University, New York, NY, United States, 4John's Hopkins, Baltimore, MD, United States, 5Radiology, Cornell, New York, NY, United States, 6Radiology and Imaging Sciences, National Institutes of Health, Bathesda, MD, United States, 7Radiology, University of Wisconson-Madison, Madison, WI, United States, 8Radiology, John's Hopkins, Baltimore, MD, United States, 9Radiology, Columbia University, New York, NY, United States |
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Chronic Obstructive Pulmonary Disease is the third leading cause of death in the United States, and affects 24 million Americans with over 65 million people affected world-wide. Up-to 58% of patients develop exertional pulmonary hypertension and right ventricular volume changes. Understanding this phenomenon, known as cor pulmonale can help us gain insight into the complex pathophysiology involved. This pilot study attempts to apply 4D flow MRI in patients with varying degrees of COPD, and assess the feasibility, reproducibility and accuracy of this technique. |
| 2860 | Kinetic energy and vorticity in the pulmonary artery in pediatric patients with repaired tetralogy of Fallot using 4D flow MRI | |
1Department of Cardiac Sciences - Stephenson Cardiac Imaging Centre, University of Calgary, Calgary, AB, Canada, 2Investigacion en Imagen y Resonancia Magnetica Nuclear, Hospital Infantil de Mexico Federico Gomez, Mexico City, Mexico, 3Physics, Universidad Autonoma Metropolitana, Mexico City, Mexico, 4Faculty of Physics and Mathematics, Benemérita Universidad Autónoma de Puebla, Puebla, 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 pediatric 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. |
| 2861 | Visualization of atrial septal defects and shunt quantification at multiple locations using 4D Flow MRI in a multicenter pilot study | |
1Erasmus MC, Rotterdam, Netherlands, 2UCSD, San Diego, CA, United States, 3Stanford University, Palo Alto, CA, United States, 4Institute Mutual Montsouris, Paris, France |
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4D Flow shows clinical promise for a wide variety of cardiovascular applications. We hypothesized that flow measurements may be valuable across a variety of scanning parameters and field strengths typically used in clinical practice. We therefore established a multicenter clinical study at 4 sites using MRI in patients with atrial septal defects. We investigated the consistency of blood flow measurements obtained along the systemic and pulmonary vasculature. Quantitative data appear robust across multiple observers and measurement locations, from data obtained across multiple sites, representing a step forward in the implementation of 4D Flow in clinical practice. |
| Exhibition Hall | Thursday 8:15 - 10:15 |
| 2862 | Automated Cardiac Resting Phase Detection in 2D cine MR images for Acquisition Window Selection in High-Resolution Coronary MRI | |
1Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 2Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 3LTS5, École Polytechnique Fédérale de Lausanne (EPFL), 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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In MR coronary angiography, the synchronization of the ECG-triggered imaging sequence with periods of minimal diastolic/systolic myocardial motion (resting phases) is essential. The selection of the resting phases is usually performed manually by an expert user. Here, automated detection of the period of minimal myocardial motion is described and tested in 30 cine patient datasets. After normalization of the cine image series, a 1D curve representative of the overall amount of motion for each cine frame is extracted. Frames belonging to diastolic/systolic resting phases are selected from such curve using peak detection and threshold-based region-growing. Testing is performed in comparison to manually expert-selected resting phases. |
| 2863 | On the link between cardiac action and magnetic field dynamics observed with NMR sensors | |
1Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland, 2Skope Magnetic Resonance Technologies Inc., Zurich, Switzerland |
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Magnetic field dynamics recorded with NMR field sensors located close to beating heart provide detailed access to cardio-vascular action. We present a realistic model that examines the physical pathways which translate mechanical heart activity into observable magnetic field dynamics. It is based on a 4D tissue model obtained from cardiac cine MR images. We confirmed that the observed signals are mainly caused by displacements of blood and muscle tissue. The presented modelling approach is expected to advance the physiological interpretation of the observed signals. |
| 2864 | The diagnostic accuracy of cardiac magnetic resonance imaging for the differential diagnosis between the left ventricular non-compaction and the negative heart remodeling in thalassemia intermedia patients | |
1Fondazione G. Monasterio CNR-Regione Toscana, Pisa, Italy, 2Università degli Studi di Palermo, Policlinico "Paolo Giaccone", Palermo, Italy |
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The Grothoff's criteria should be used in the clinical practice in order to improve the specificity of the diagnosis of LVNC and distinguish LVNC and negative heart remodeling in β-TI. |
| 2865 | Determining prolate spheroidal modes of cardiac deformation directly from tagged heart images | |
1Radiation Oncology, University of Florida, Gainesville, FL, United States, 2Biomedical Engineering, University of Florida, Gainesville, FL, United States |
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An approach was developed to compute modes of left ventricular wall deformation directly from tagged MR images via generation of simulated tagged images undergoing modes of deformation expressed in a prolate spheroidal coordinate system (PSCS). This eliminates the laborious pre-processing step of detecting tags and/or points along tags while employing an efficient and accurate representation of LV wall motion in terms of PSCS modes. The method was tested with simulated and low-quality human image data sets with acceptable initial results. It is hoped that this advancement will help rekindle application of quantitative MR tagging in the clinical and research arenas. |
| 2866 | Three-dimensional Bi-ventricular Myocardial Feature Tracking for Congenital Heart Disease Using Standard Cardiac Cine MRI with Interpolation Technique Based on Moving Gradients | |
1Department of Radiological Technology, Faculty of Fukuoka Medical Technology, Teikyo University, Omuta, Japan, 2Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 3Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan, 4Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 5Department of Diagnostic Imaging & Nuclear Medicine, Tokyo Women’s Medical University, Tokyo, Japan |
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Patients with congenital heart disease (CHD) often have complicated ventricular motion and configuration. Myocardial feature tracking (MFT) MRI can quantitatively analyze 2-dimensional myocardial motion. Although three-dimensional (3D) MFT is required for the patients with CHD, standard cine MRI is limited the setting of thin slice thickness attributed to increasing scan time. In this study, we analyzed bi-ventricular function with 3D MFT using only standard cine MRI datasets reconstructed by moving gradients based image interpolation technique. As the result, 3D MFT is useful to evaluate bi-ventricular function for patients with CHD, and can be easily applied to routine clinical MR examination. |
| 2867 | Real-Time Cardiac Functional Imaging Using an Arrhythmia-Robust Radial Imaging Sequence | |
1GE Global Research Europe, Garching bei München, Germany, 2Cardiac Center of Excellence, GE Healthcare, Garching bei München, Germany, 3GE Healthcare, Menlo Park, CA, United States, 4GE Healthcare, Madison, WI, United States, 5Radiology, University of Wisconsin - Madison, Madison, WI, United States, 6Medical Physics, University of Wisconsin - Madison, Madison, WI, United States, 7GE Healthcare, Waukesha, WI, United States |
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Cardiac cine datasets are difficult to obtain in the presence of arrhythmia or poor gating signal. Here, completely ungated radial real-time imaging may help. Cartesian real-time imaging usually offers compromised spatial resolution to maintain sufficient temporal resolution. Hence, we propose a radial bSSFP-based real-time approach with Golden Angle increment which enables view sharing of temporally adjacent projections. To minimize temporal blurring, a narrow tornado shaped filter, followed by subsequent iterative SENSE reconstruction, was used. Remaining streaking artifacts were reduced by a principal component analysis based technique. Results show good agreement in terms of image quality to a standard Cartesian cine dataset. |
| 2868 | Left Atrial Enlargement and Systolic Failure Measured by Cardiac MRI in Severe Isolated Mitral Regurgitation with Preserved Left Ventricular Ejection Fraction | |
1Auburn University MRI Research Center, Auburn University, Auburn, AL, United States, 2Electrical and Computer Engineering, Auburn University, Auburn, AL, United States, 3Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL, United States, 4Birmingham Veterans Affairs Medical Center, Birmingham, AL, United States, 5MR R&D, Siemens Healthcare, Malvern, PA, United States |
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Mitral regurgitation (MR) from degeneration of the mitral valve (MV) results in a relatively low-pressure form of volume overload caused by excess volume being ejected through a secondary ejection pathway into the left atrium (LA). Optimal timing for MV repair is under debate because a spuriously normal left ventricular (LV) ejection fraction belies severe myocardial damage and that the onset of symptom has increased risk for LV dysfunction post MV repair. LA function measured by cMRI may be an important indicator for timing of MV repair before the onset of symptoms in patients with well-preserved LV systolic function. |
| 2869 | One Minute Free-Breathing 3D Cardiac Cine Imaging with Adaptive Respiratory Self-Gating Efficiencies | |
1University of California San Francisco, San Francisco, CA, United States, 2New York University, New York, NY, United States |
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Cardiac cine imaging has become the standard for cardiac functional measurements. However, a series of breath-holds are required to acquire 2D cine images covering the whole heart. The capability of children or sick patients to perform consistent breath-holds is limited and often results in non-diagnostic images. We aim to develop a fast and reliable 3D imaging technique for cardiac functional assessment, which only requires one minute of scan time during free breathing. To compensate for respiratory motion, which varies substantially among subjects, we propose to apply adaptive respiratory self-gating efficiencies to generate reliable image quality for 3D cardiac cine imaging. |
| 2870 | Evaluation of left ventricular (LV) geometric models for estimating LV volumes in 980 children using cardiac cine magnetic resonance imaging | |
1Diagnostic and Interventional Radiology, CHI St Luke's Health, Houston, TX, United States, 2Center for Coronary Artery Anomalies, Texas Heart Institute, Houston, TX, United States, 3Philips Healthcare, Cleveland, OH, United States |
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The results from this study that included cine SSFP images of the LV from 980 children show that LV volumes computed using commonly used bi-plane and tri-plane ellipsoidal models deviate significantly when compared to LV volumes estimated from a stack of short axis slices. A cut-cone+cone model of the LV proposed in this manuscript can estimate metrics describing LV function (EDV, ESV, and EF) with just two projections that are comparable to that obtained from an entire stack of short-axis slices. |
| 2871 | Feature-Tracking for Volume and Strain with Subtly Tagged SSFP | |
1Physiology & Experimental Medicine, University of Toronto, Toronto, ON, Canada, 2Siemens Healthcare, Erlangen, Germany, 3Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand |
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A novel subtly tagged cardiac acquisition coupled with non-rigid registration is developed and tested in healthy volunteers. The technique produces myocardial strain characterization and ventricular volumetrics within a single scan. |
| 2872 | Inter-center reproducibility of left ventricular circumferential strain analysis with spatial modulation of magnetization imaging analysis in healthy and repaired Tetralogy of Fallot patients | |
1National Heart Centre Singapore, Singapore, Singapore, 2The University of Auckland, New Zealand, 3Duke-NUS Medical School Singapore, Singapore, Singapore |
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The aim of this study was to examine inter-center reproducibility of tagging magnetic resonance imaging (MRI) analysis in human patients undergoing either 1.5T or 3.0T MR examinations. A total of 20 subjects, 10 heathy subjects and 10 patients with repaired tetralogy of Fallot (rTOF), aged between 18 and 69 years, underwent either 1.5T or 3.0T MR scans. Circumferential strain (CS) from base, mid, and apex regions were analysed using CIM v8.4 at two centres (NHCS Singapore and University of Auckland). Reproducibility was moderate at the base (ICC 0.765), and excellent at the mid (0.979) and apex (0.982) regions. Overall reproducibility was excellent in both healthy controls and rTOF patients (ICC: 0.956 and 0.932), and at both 1.5T and 3.0T (0.972 and 0.940). |
| 2873 | Cardiovascular Magnetic Resonance Imaging Evaluation of Right Ventricular Efficiency in Health and Disease: State of the Art | |
1Radiology, University of Wisconsin - Madison, Madison, WI, United States, 2University of Wisconsin - Madison, WI, United States |
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Assessing RV function is complex, particularly in patients with RV dysfunction. Traditional indices, such as RV volumes and ejection fraction, incompletely describe the alterations that occur with changes in RV volume or afterload. New CMR methods of assessing RV efficiency based on strain and energetics have the potential to detect dysfunction earlier than currently used approaches. |
| 2874 | Improved Time Efficiency and Workflow for Fully Self-Gated Non-Contrast 5D Imaging of the Heart | |
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, 3Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, 4Department of Radiology, Case Western Reserve University, Cleveland, OH, United States |
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Current solutions for cardiac and respiratory motion resolved whole-heart MR imaging rely on ECG signal to synchronize data acquisition, sub-optimal strategies for fat suppression which interrupts steady-state magnetization, or contrast agent for anatomical differentiation. To address these hurdles, we present a self-gated framework with bSSFP contrast and binomial spectrally selective excitation pulse which suppresses epicardial fat signal without interrupting steady-state. When compared to existing sequences, the proposed framework reduces energy deposition and acquisition time while preserving or even improving the final image quality. |
| 2875 | Global and regional wall motion abnormalities detected using strain-encoded MRI in comparison with late gadolinium enhancement in patients with sarcoidosis | |
1Hokkaido University Graduate School of Medicine, Sapporo, Japan, 2Hokkaido University Hospital, 3Hokkaido University, 4Hokkaido University Graduate School of Medicine |
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We investigated global and regional myocardial wall motion abnormalities using strain-encoded (SENC) MRI in comparison with late gadolinium enhancement (LGE) in patients with systemic sarcoidosis. Fourteen patients were retrospectively evaluated. We found that global strain assessed using SENC MRI correlated well with global left ventricular (LV) dysfunction and the extent of LGE. In addition, regional longitudinal strain significantly decreased in segments with >10% LGE. SENC MRI has the potential to detect global and regional LV dysfunction and to predict the extent of LGE. |
| 2876 | 3D left atrial strain imaging based on multi-slice radial cine and feature tracking | |
1Yale University, New Haven, CT, United States |
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Left atrial (LA) strain is an important marker of left atrial remodeling. Two-dimensional atrial strain has been studied using echocardiography and MRI cine. Here we develop a 3D strain method, using volumetric cine data sets at multiple phases. The volumes were registered and 3D strain maps were generated, demonstrating patterns of regional strain in the LA. |
| 2877 | Respiratory variation in left ventricular cardiac function with 3D double-golden-angle whole-heart cine imaging | |
1Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden |
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Respiratory variation in ventricular volume can potentially provide clinically important information in cardiac diseases involving left ventricular stiffness changes, and can be measured using respiratory resolved imaging. 3D double-golden-angle radial data were acquired during free breathing, and respiratory self-gating signals were extracted from k-space. All radial spokes were sorted into 8 respiratory phases and one end-diastolic cardiac phase and left ventricular end-diastolic volume (EDV) was segmented from a short-axis image stack. Respiratory induced changes in EDV were demonstrated and changed 9.0±2.3 % with respect to maximum expiratory EDV. |
| 2878 | 3D-Cine Whole-heart Magnetic Resonance Imaging Using a Novel Prospective Respiratory Self-Gating Technique | |
1Cardiology and Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States |
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We developed a novel prospective respiratory motion compensation algorithm, Heart-NAV, for free-breathing retrospective electrocardiogram (ECG)-gated 3D-cine steady-state free precession whole-heart magnetic resonance imaging. In 10 patients, there was good agreement between the 3D-cine and conventional breath-hold 2D-cine imaging measurements of ventricular volumes. The mean scan time for the 3D-cine acquisition was 5.9±2.7 minutes. Advantages of the Heart-NAV approach include real-time motion correction allowing for immediate in-line image reconstruction, compatibility with a variety of k-space filling approaches, and utilization of standard scanner hardware/software. Such a 3D-cine approach eliminates the need for breath-holding and simplifies planning for ventricular function assessment. |
| 2879 | 3D Stack-of-Stars Cardiac Cine MRI: Free-Breathing vs. Respiratory Gated Reconstruction | |
1Internal Medicine II, University Hospital of Ulm, Ulm, Germany, 2Department of Cardiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, People's Republic of China |
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3D cardiac cine MRI provides consistent data for complete LV analysis in a single scan. As this acquisition is too long for a breathhold, respiratory gating is typically applied. The aim of this study is to investigate whether respiratory gating is also required for 3D cardiac cine MRI when using a Stack-of-Stars acquisition. Ungated and Self-Gated reconstructions are compared visually and for LV function parameters. As no motion artifacts are apparent even in the ungated cine data, and LV function results are comparable to the gated images, ungated reconstruction seems to be feasible for LV analysis. |
| 2880 | Improvements in Cardiac MR Elastography Using Reduced FOV Techniques | |
1Radiology, Mayo Clinic, Rochester, MN, United States |
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Single-shot spin-echo EPI (SS-SE-EPI) has been utilized for cardiac MR Elastography (cMRE) due to its fast imaging speed and insensitivity to cardiac motion. However, the long echo train in SS-EPI makes it vulnerable to image distortion, which can be prominent in cMRE due to the large susceptibility gradient present at the heart-lung interface. In this study, a reduced phase FOV (rFOV) technique combined with a 2D selective excitation has been implemented in the cMRE. And the results showed that the MRE image quality was improved with reduced image distortions and higher SNR. |
| 2881 | Application of optimized TPAT technique in evaluating arrythmia patients' cardiac function | |
1Beijing Anzhen Hospital, Beijing, People's Republic of China, 2Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, People's Republic of China, 3MR Collaborations NE Asia, Siemens Healthcare, Beijing, China |
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Traditional CMR sequences are useful tools for assessing cardiac structure and function, However, the poor image quality and motion artifacts caused by arrhythmia may hamper the diagnostic quality of CMR images. We hypothesized that the optimized temporal parallel acquisition technique (TPAT) may improve this situation by allowing free-breathing of subjects and meanwhile provides a similar diagnostic values for radiologists . |
| 2882 | Cardiovascular Magnetic Resonance (CMR) imaging quantification of right and left ventricular strain in repaired Tetralogy of Fallot: Preliminary results in 10 patients and 10 normal volunteers | |
1Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States |
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Patients with repaired Tetralogy of Fallot (rTOF) have worsening right and left ventricular function due to their lack of a functional pulmonary valve and the resulting pulmonary insufficiency. Determining the severity of this dysfunction is important for deciding when interventions like pulmonary valve replacement become necessary. Radial and longitudinal myocardial strain is a functional parameter than can aid in this clinical decision. In this small study, myocardial strain was calculated using tissue tracking software applied to axial cine balanced steady-state free precession (bSSFP) images. Significant differences in RV and LV radial and longitudinal strain were found between patients with rTOF and healthy volunteers. |
| 2883 | Left Ventricle Circumferential Strain from Radially Tagged Images through CIRCOME combined by SinMod | |
1Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran |
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Left ventricle function can be evaluated by measuring circumferential strain. CIRcumferential COMpression Encoding (CIRCOME), as a technique for quantification of circumferential strain, needs local frequency and displacement maps during deformation. This study aims to use sine wave modeling approach for estimation of local spatial frequency and displacement maps used in CIRCOME for radially tagged series of images. Circumferential strain computed from proposed method shows expected results in agreement with previous studies. |
| 2884 | Reducing Specific Energy Deposition in Free Breathing Balanced Steady-State Free Precession (bSSFP) Cine Imaging using Cardio-respiratory Synchronization | |
1Philips Healthcare, Houston, TX, United States, 2Baylor St. Luke's Medical Center, Houston, TX, United States, 3Diagnostic and Interventional Radiology, Baylor St. Luke's Medical Center, Houston, TX, United States, 4Department of Diagnostic and Therapeutic Radiology, Baylor St. Luke's Medical Center, Houston, TX, United States |
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Free breathing cine bSSFP sequences with minimal compromises in spatio-temporal resolution requirements are highly desirable in patients who can not hold their breath, e.g., sedated patients, patients with poor cardiopulmonary reserve, patients with arrhythmia etc. The results from this prospective clinical study of 14 clinical patients shows that a cardiorespiratory synchronized (CS) sequence can reduce specific energy deposition (0.68 ± 0.24 kJ/kg) by 40% compared to a respiratory gated (RG) sequence (1.2 ± 0.36 kJ/kg) without compromising spatial, temporal, and contrast resolution thus permitting the prescription of bSSFP cine sequences with higher spatial or temporal resolution, and coverage. |
| 2885 | A Comparison Study between the 2D Breath-holding and 3D Free-breathing approaches to in vivo Cardiac Quantitative Susceptibility Mapping | |
1Meinig School of Biomedical Engineering, Cornell University, New York, NY, United States, 2Radiology, Weill Cornell Medicine, New York, NY, United States, 3Medicine, Weill Cornell Medicine, NY, United States, 4Medicine, Weill Cornell Medicine |
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Our previous study showed that high quality in vivo cardiac susceptibility maps (QSM) can be obtain using a 2D breath-hold (2DBH) sequence. However, the 2DBH approach is vulnerable to slice misregistration caused by inconsistent breath-holds, which will cause artifacts in the resulting susceptibility maps. Here we introduce a 3D navigator gated sequence (3DNAV) which allows for free-breathing during acquisition, and compare it to the 2DBH approach. |
| 2886 | Quantification of Left Ventricular Dyssynchrony and Action Time in Patients with Fabry Disease by Magnetic Resonance Tissue Phase Mapping | |
1Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, 2Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, 3Medical Physics, University Hospital Freiburg, Freiburg, Germany, 4Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan |
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Recent studies showed that LV dyssynchrony and deceleration time can be recognized as an important predictor of poor outcome in patients. However, the regional myocardial function investigated by MRI is less discussed. In this study, we applied MR tissue phase mapping (TPM) and aim to investigate the myocardial dyssynchrony and action time in LV for Fabry disease (FD). We observed increased longitudinal dyssynchrony and lower systolic action time in FD group. In conclusion, the quantification of LV myocardial dyssynchrony and action time may provide useful information to comprehend the impaired cardiac manifestation and diastolic dysfunction in patients with FD. |
| 2887
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Interaction of Pulmonary Regurgitation Flow and Myocardial Motion Velocity in Patients with Repaired Tetralogy of Fallot | |
1Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, 2Department of Radiology Kaohsiung, Kaohsiung Veterans General Hospital, 3Department of Medical Imaging Taipei, National Taiwan University Hospital |
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In this study, we measured pulmonary regurgitation fraction and three-directional myocardial wall motion velocities to establish indices for characterizing cardiac function in patients with repaired tetralogy of Fallot (rTOF). We aim to reveal the interaction of pulmonary regurgitation fraction and myocardial motion velocity and thereby to speculate the myocardial damage in rTOF patients. In conclusion, the pulmonary RF displayed |
| Exhibition Hall | Thursday 13:00 - 15:00 |
| 2888 | The Uesfulness of Intravoxel Incoherent Motion Diffusion-weighted Imaging for Predicting the Prognosis of Patients with Acute Myeloid Leukemia | |
1Second Hospital of Shanxi Medical Hospital, Taiyuan, People's Republic of China, 2Radiology, Second Hospital of Shanxi Medical University, Taiyuan, People's Republic of China |
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Intravoxel Incoherent Motion (IVIM) is capable of providing both diffusion and perfusion quantification using a single imaging study at the same time, without the need for intravenous contrast injection. acute myeloid leukemia (AML) patients with complete remission and non-complete remission could exhibit different characterizations before treatment in perfusion and tissue cellularity of the lumbar bone marrow. This study was to investigate the usefulness of IVIM parameters in evaluation of prognosis in AML patients. |
| 2889 | Repeatability of perfusion parameters in free-breathing dynamic contrast-enhanced MRI of malignant hepatic tumors | |
1Ajou University Hospital, Ajou University School of Medicine, Suwon, Korea, Republic of, 2Asan Medical Center, Ulsan University College of Medicine, Seoul, Korea, Republic of, 3Bioimaging Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea, Republic of, 4Severance Hospital, Yonsei University College of Medicine, Seoul, Korea, Republic of |
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In dynamic contrast-enhanced (DCE)-MRI, establishing a high level of repeatability is essential to ensure reliability of changes in perfusion parameters over longitudinal studies in an individual subject. To assess the repeatabilities of perfusion parameters and identify the effect of T1 map on them, we performed two sequential free-breathing DCE-MRI studies in patients with solid hepatic malignancies. Our results showed that Kep had the highest repeatability, and the repeatabilities of all perfusion parameters were boosted when fixed T1 value (800 ms) was used instead of values obtained from T1 mapping. |
| 2890 | Quantitative evaluation of the effect of temporal resolution and acquisition duration on the accuracy of DCE-MRI measurements in a prostate phantom | |
1School of Medicine / National Centre for Advanced Medical Imaging (CAMI), Trinity College University of Dublin / St James's Hospital, Dublin 8, Ireland, 2School of Physics & Medical Ultrasound Physics and Technology Group, Centre of Industrial Engineering Optics, FOCAS, Dublin Institute of Technology, Dublin 8, Ireland |
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A novel anthropomorphic prostate phantom test device was used to investigate the effects of temporal resolution (Tres) and acquisition duration (AD) on the accuracy of contrast time-intensity curves measured using dynamic contrast-enhanced MRI. When quantitatively compared to ground truth values, large errors in derived pharmacokinetic (PK) parameters (up to 230%) were found for Tres values > 8.1 s and AD values < 360 s. The data demonstrate the critical and sensitive dependence of the accuracy of measured PK output parameter values on the acquisition protocol used, while such phantom studies can help identify optimal acquisition parameters for DCE-MRI scans |
| 2891 | Improved sensitivity for rectal cancer differentiation by T2*-correction in DCE-MRI | |
1Oslo University Hospital, Oslo, Norway, 2Akershus University Hospital, Norway, 3Akershus University Hospital, Lørenskog, Norway, 4Sunnmøre MR-klinikk, Ålesund, Norway |
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Quantitative pharmacokinetic analysis from DCE-MRI often neglects CA-induced T2*-effect when converting signal intensity (SI) changes in tissue to CA concentration. The acquired signal may thus be significantly affected by T2* signal attenuation, which in turn results in errors in the DCE-derived parameters. This work utilized a dynamic multi-echo acquisition for extrapolation back to TE=0, thus providing both T2*-corrected and uncorrected measurements of DR1, and investigates the how the correction for T2*-attenuation effects may affect the sensitivity for rectal cancer differentiation by DCE-MRI. The T2*-corrected data showed improved differentiation of rectal cancer. |
| 2892 | Enhancement of Lesion Detection through Feature Projection and Classification of Perfusion Parameters | |
1Cornell University, Ithaca, NY, United States, 2Weill Cornell Medicine, New York, NY, United States |
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Perfusion analysis is a powerful tool to quantitatively characterize lesions. This can further be extended to differentiate lesions through comparison perfusion parameters. Typically there is overlap in perfusion parameters which makes it difficult to distinguish lesions. We demonstrate perfusion analysis combined with feature projection and classification enhances lesion detection by increasing separability and extracting features of the lesions simultaneously which can be used in automation of lesion detection. |
| 2893 | Quantitative Ultra-short Time-to-Echo Contrast-Enhanced Magnetic Resonance Imaging (qUTE-CE MRI) technique use Ferumoxytol as a Positive-Contrast Agent to Delineate Nanoparticle Accumulation in Tumors | |
1Mechanical and Industrial Engineering, Northeastern University, BOSTON, MA, United States, 2Radiology, Massachusetts General Hospital, 3Radiology, Harvard Medical School, 4Physics, Northeastern University, Boston, MA, United States, 5Nanomedicine Science & Technology Center, Northeastern University, Boston, MA, United States, 6Psychology, Northeastern University, Boston, MA, United States |
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Here we demonstrate quantitative ultra-short time-to-echo contrast-enhanced magnetic resonance imaging (qUTE-CE MRI) technique, which employs FDA-approved ferumoxytol as a positive-contrast agent to delineate nanoparticle accumulation in tumors. |
| 2894 | Evaluation of DCE-MRI Exam with High-Temporal Resolution for Breast Cancer Diagnosis in a Biopsy Cohort | |
1Center for Advanced Imaging Innovation and Research, 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 feasibility of using GRASP DCE-MRI for contrast kinetic analysis to determine lesion malignancy. This IRB-approved retrospective study included 73 women who underwent MRI-guided biopsy scans. The plasma flow in the malignant group was significantly higher than that of the benign group with the area under the curve of 0.77. The results in this study successfully demonstrate that the GRASP DCE-MRI method can be used to acquire adequate high-temporal and high-spatial resolution images of the breast for contrast kinetic analysis. |
| 2895 | Dynamic Contrast-Enhanced MRI Using Spatial Prior Knowledge | |
1Institute of Scientific Instruments of the CAS, Brno, Czech Republic, 2Institute of Information Theory and Automation of the CAS, Praha, Czech Republic, 3Department of Cytokinetics, Institute of Biophysics of the CAS, Brno, Czech Republic, 4Center of Biomolecular and Cellular Engineering, International Clinical Research Center, Brno, St. Anne’s University Hospital Brno, Brno, Czech Republic, 5Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic, 6Department of Biomedicine, University of Bergen, Bergen, Norway |
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A method to improve reliability of DCE-MRI is presented. It is based on the assumption that neighboring voxels have similar physiological properties. It is formulated as a total variation regularization of the perfusion parameter maps. The method is applied to the adiabatic approximation of the tissue homogeneity model (ATH). Evaluation was done on data of five tumor bearing mice recorded using two contrast agents with different molecular weights. The resulting perfusion parameter maps were more spatially consistent with preserved edges. |
| 2896 | Are radiation-induced perfusion changes in normal appearing brain tissue a confounding factor in tumour response evaluation with DSC-MRI? | |
1Surgical Sciences, Uppsala University, Uppsala, Sweden, 2Biomedical Technology, Medical Physics and IT, Uppsala University Hospital, Uppsala, Sweden |
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Radiation-induced brain perfusion changes after radiotherapy have not been studied extensively with DSC-MRI. Tumour perfusion is often normalised to contralateral normal-appearing white matter, why knowledge about radiation effects on perfusion in normal brain tissue is essential. Ten patients were examined with DSC-MRI at 1.5 T before and repeatedly after RT. Multiple volumes were drawn in normal brain tissue. Radiation dose for all volumes were available. Significant CBV and CBF decrease after radiotherapy was visible in grey matter volumes and showed tendency to recover. High radiation dose regions should be avoided when normalising DSC-MRI derived tumour perfusion values. |
| 2897 | A population-based digital reference object (DRO) for optimizing dynamic susceptibility contrast (DSC) MRI methods for clinical trials | |
1Translational Bioimaging, Barrow Neurological Institute, Phoenix, AZ, United States, 2Diagnostic Imaging, Rhode Island Hospital, Providence, RI, United States |
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The standardization of DSC-MRI has been confounded by a lack of consensus on DSC-MRI methodology for preventing potential rCBV inaccuracies, including the choice of acquisition protocols and post-processing algorithms. To address these issues, we developed a digital reference object (DRO) aimed at validating image acquisition and analysis methods for accurately measuring rCBV in glioblastomas. The DRO was developed using trained physiological and kinetic parameters derived from in vivo data, unique voxel-wise 3D tissue structures, and a validated MRI signal computational approach. The DRO’s ability to produce reliable signals was validated by comparison to separate cohort of patient data. |
| 2898 | Probing infiltration of the normal brain by glioblastoma using magnetic resonance perfusion and permeability techniques | |
1Glasgow Experimental MRI Centre, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom, 2Translational Radiation Biology, Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom |
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MRI techniques probing brain perfusion and blood-brain barrier (BBB) permeability were assessed in their ability to detect low tumour invasion in mouse glioblastoma models. A multiple boli Arterial Spin Labeling technique was optimised, achieving high SNR perfusion imaging. Diffusion-weighted arterial spin labelling allowed to separate fast motion vascular components of the signal from slow motion tissue components, providing with BBB permeability weighted maps. Evaluation was performed by comparison with conventional MRI and immunohistochemistry sections (HLA) cut in the MRI plane . Both perfusion weighted maps and BBB permeability weighted maps allowed to identify low tumour regions not detected with conventional MRI techniques. |
| 2899 | Application of Monoexponential, biexponential and stretched exponential Diffusion-weighted MR Imaging for Differentiating between Minimal Fat Angiomyolipoma (MFAML) and Papillary Renal Cell Carcinoma (PRCC). | |
1Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wu Han, People's Republic of China |
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Accurate preoperative differentiation between MFAML and PRCC is important to determine appropriate treatment strategies.In this study, the preliminary date from our study show that different models of DWI may demonstrate various aspects of tissue properties.fp and α may provide additional information and could lead to improved differentiation with better sensitivity and specificity between MFAML and PRCC compared with conventional imaging parameters. |
| 2900 | DDC and α estimates from the stretched exponential model are more robust to variations in b-value selection than ADC estimates, in a cohort of 42 cervical tumours | |
1Cancer Research UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom, 2MRI Unit, The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom |
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The influence of b-value selection on fitted parameters from the stretched exponential model (distributed diffusion coefficient DDC, and ‘stretching parameter’ α) and mono-exponential model (apparent diffusion coefficient ADC) was investigated in a cohort of 42 patients with cervical tumours. Diffusion-weighted images images were acquired using 9 b-values between 0 and 800smm-2, and fitted voxel-by-voxel using all b-values (0 to 800smm-2) and b-values n-to-800smm-2 (where n is 20,40,60,80,100, or 300smm-2). ADC estimates are highly sensitive to b-value selection, with reduction in ADC when low b-values are excluded, whereas DDC and α are more robust to differences in b-value selection. |
| 2901 | Combined analysis of ten DW-MRI studies demonstrates excellent repeatability of apparent diffusion coefficient estimates in extra-cranial soft-tissue tumours | |
1Cancer Research UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom, 2MRI Unit, The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom, 3Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, United Kingdom, 4Drug Development Unit, The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom, 5Division of Clinical Studies, The Institute of Cancer Research, London, United Kingdom |
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Repeatability of ADC estimates from ten diffusion-weighted MRI studies in extra-cranial soft tissues (nine patient studies and one healthy volunteer study, with a total of 111 subjects) were analysed in combination using the Radiological Society of North America (RSNA) Quantitative Imaging Biomarkers Alliance (QIBA) framework for assessment of technical performance of imaging biomarkers, in order to investigate factors affecting ADC repeatability. Coefficient of variation was between 2 and 7% for all studies, with no marked differences between imaging protocols or study populations, and better repeatability in large tumours compared with smaller tumours, indicating that ADC is a robust imaging metric with excellent repeatability in extra-cranial soft-tissue tumours. |
| 2902 | Correlation of Intra-Voxel incoherent motion (IVIM) imaging and Dynamic Susceptibility Contrast (DSC) MRI for high and low grade gliomas | |
1Dayananda Sagar Institutions, Bangalore, India, 2National Institute of Mental Health, Bangalore, India |
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The aim of this study was to validate the feasibility of Intravoxel Incoherent Motion (IVIM) imaging of human brain gliomas; and to differentiate between high grade and low grade gliomas using IVIM parameters (f, d, D, fD*). These parameters were then compared to CBV maps obtained through DSC-MRI to evaluate the role of non-contrast agent based perfusion imaging. Results obtained showed that IVIM perfusion fraction f could be used to differentiate between high and low-grade brain gliomas |
| 2903 | Differential diagnosis of Ocular adnexal lymphoma and idiopathic orbital inflammation：radiomics imaging features and their predictive performance | |
1Affiliated Tongren Hospital，Capital Medical University, Beijing, People's Republic of China, 2Affiliated Tongren Hospital，Capital Medical University, 3Key Laboratory of Molecular Imaging,Chinese Academy of Sciences, People's Republic of China, 4Key Laboratory of Molecular Imaging,Chinese Academy of Sciences |
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Differential diagnosis of Ocular adnexal lymphoma (OAL) and idiopathic orbital inflammation (IOI) is very important due to their quite different therapeutic modalities and prognosis. However, it is not easy for both ophthalmologists and pathologists. Can the emerging radiomics enhance the diagnostic efficiency? This research devoted evidence for this question. |
| 2904 | Prognostic Characterization of Prostate Cancer from Benign Tissue MRS | |
1Molecular Pathology, Massachusetts General Hospital, Charlestown, MA, United States, 2Massachusetts General Hospital, Charlestown, MA, United States, 3Massachusetts General Hospital, Boston, MA, United States |
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While serum prostate specific antigen (PSA) testing improved early detection of prostate tumors, implementation of this tool also created a large patient population in which identified cancer lesions were actually indolent. For patients who choose to undergo prostatectomy, cancer aggressiveness can only be determined by post-procedure pathology analysis of cancerous tissue. Additionally, cancer recurrence predictions are often unreliable. As an alternative method to aid decisions regarding treatment, we sought to develop MRS tools which can predict cancer aggressiveness based on the novel use of histologically benign (Hb) tissue. |
| 2905 | Texture Analysis on Diffusion Weighted MRI in Osteosarcoma | |
1Center for Biomedical Engineering, Indian Institute of Technology, New Delhi, India, 2Radiodiagnosis, All India Institute of Medical Sciences, New Delhi, India, 3Medical Oncology, Dr. B.R.Ambedkar Institute-Rotary Cancer Hospital, All India Institute of Medical Sciences, New Delhi, India, 4Department of Biomedical Engineering, All India Institute of Medical Sciences, New Delhi, India |
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Texture analysis (TA) uses mathematical approach to characterize the spatial distribution of signal intensity variations in an image, and extracts quantitative information that are otherwise imperceptible qualitatively. Good soft tissue contrast of MRI facilitates TA to produce promising results in diagnosis and prognosis. Diffusion Weighted (DW) MRI based TA might provide additional useful information as DWI captures early cellular changes in tumors in terms of corresponding intensity variations. We computed textural features in patients with Osteosarcoma. Experimental results revealed that textural features show good discrimination among normal and tumour ROI thus might be useful as diagnostic and prognostic marker. |
| 2906 | Evaluation of 4D-T2w MRI methods for lung radiotherapy treatment planning with application to an MR-linac | |
1Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, United Kingdom, 2CR-UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom, 3Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany |
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Due to enhanced soft-tissue contrast, 4D-T2w MRI could improve lung tumour target delineation in radiotherapy compared with 4D-CT; reducing planning margins and dose to healthy tissue for treatments on an MR-linac. We have developed a method for generating 4D-T2w MRI, where 3D-T2w MRI is warped using motion vector fields; calculated by image-registration between respiratory phases of 4D-T1w MRI (the MVFP method). Here, 4D-T2w MRI calculated with MVFP and with amplitude-binning of continuously acquired 2D-T2w MRI, are compared. 4D-T2w MRI from the MVFP method exhibited higher image quality and geometrical fidelity than the 2D-binning scheme, but displayed possible motion under-estimation. |
| 2907 | 4D-T2 weighted MRI for lung radiotherapy treatment planning | |
1Joint Department of Physics, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, United Kingdom, 2CR-UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom, 3Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany |
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Compared to 4D-CT, 4D-T2w MRI should better characterise respiratory motion in radiotherapy, due to its superior soft tissue contrast. However, 4D-T2w MRI is difficult to acquire due to the long echo and repetition time required. Here, 4D-T2w MRI is obtained by applying motion information from a 4D-T1w volume to a static 3D-T2w volume. For three patients, 4D-T2w MRI was compared to 4D-T1w MRI. Diaphragm positions were consistent to <1.5mm. A method to calculate 4D-T2w MRI, with potential application to an MR-linac, is presented and verified. |
| 2908 | Can diaphragm motion function as a surrogate for motion of esophageal tumors during treatment? | |
1Department of Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands, 2Department of Surgery, University Medical Center Utrecht, Utrecht, Netherlands |
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Esophageal tumors show large motion in cranio-caudal direction, with a Peak-to-Peak (P-t-P) range of 2.7 to 24.5mm. In case the motion of the tumor could be followed during radiotherapy treatment, this would enable treatment margin reduction. It is researched whether the motion of the diaphragm is correlated with the breathing motion and drift we can detect in esophageal tumors since it could function as surrogate for tumor motion during treatment. A high correlation was found between both motion patterns and correction of the tumor motion using the diaphragm drift resulted on average in a reduction in P-t-P motion in all patients. |
| 2909 | Radiomic features extracted from T2w MRI differentiates KRAS mutational status in rectal cancers: A pilot study | |
1Radiology, Baylor College of Medicine, Houston, TX, United States, 2KFMC - Riyadh, Saudi Arabia, 3Biomedical Engineering, Case Western Reserve University, 4KFSH - Qassim |
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Contemporary management of rectal cancer includes consideration of adjuvant anti EGFR therapy; however, KRAS mutational status profiling is mandatory prior to initiation of this therapy. KRAS mutational status is typically assayed on tissue samples (biopsy/surgical specimens). Radiomic features have demonstrated the ability to quantitatively characterize image phenotypic appearance associated with genotype expression in different tumors. We explored the utility of multi-scale, multi-oriented filter banks to define radiomics signatures that distinguish KRAS mutated vs wildtype tumors on T2W MRI. Initial results indicate that macro-scale radiomic features depict significantly different responses between the 2 genotypic groups. |
| 2910
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The role of ADC histogram analysis in discriminating between benign and malignant tumours in children | |
1Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom, 2Department of Paediatric Oncology, Birmingham Children's Hospital, Birmingham, United Kingdom, 3Department of Paediatric Radiology, Birmingham Children's Hospital, Birmingham, United Kingdom |
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We evaluated histogram analysis of ADC maps to differentiate benign from malignant solid paediatric tumours in children and distinguish tumour type. Fifty children (38 malignant, 12 benign tumours) were imaged using multi-b value diffusion-weighted MRI at diagnosis. Whole tumour regions-of-interest (ROIs) were drawn, ADC histograms constructed, and median, 2nd to 98th percentile ADC values, skewness, kurtosis and entropy calculated. ADC histogram parameters were significantly different between malignant and benign lesions, with skewness and kurtosis being the most predictive of malignancy. |
| Exhibition Hall | Thursday 13:00 - 15:00 |
| 2911 | ADC and D from diffusion-weighted MRI correlate with histopathological assessment of nuclear-to-stromal ratio, and histology confirms Dixon fat fraction in retroperitoneal sarcomas | |
1Cancer Research UK Cancer Imaging Centre, The Institute of Cancer Research, London, United Kingdom, 2MRI Unit, The Royal Marsden NHS Foundation Trust, Sutton, United Kingdom, 3Department of Histopathology, The Royal Marsden NHS Foundation Trust, London, United Kingdom, 4Department of Radiotherapy, The Royal Marsden NHS Foundation Trust, London, United Kingdom, 5Department of Surgery, The Royal Marsden NHS Foundation Trust, London, United Kingdom |
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Soft-tissue sarcomas are often highly heterogeneous tumours. Clinical trials of non-surgical treatments, for example combined radiotherapy and systemic agents, require non-invasive methods for response assessment. Quantitative MRI provides non-invasive response assessment of the whole tumour volume, but metrics require validation against histopathology. In this study, 26 patients with retroperitoneal sarcoma were imaged prior to surgery, with written consent, as part of a prospective single-centre study. Diffusion-weighted MRI parameters (ADC, and D from IVIM) showed correlation with nuclear-to-stromal ratio, and were also related to stroma type and stroma grade. Dixon-derived fat fraction correlated strongly with histopathological assessment of fat fraction. |
| 2912 | Label-free CEST MRI detection of albumin and albumin-based nanoparticles | |
1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States, 2Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States, 3Department of Radiology, Guangzhou Panyu Central Hospital, 4Ludwig Center, Howard Hughes Medical Institute and Sidney Kimmel Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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Albumin is emerging as one of the most attractive drug carriers for the targeted delivery of therapeutic peptides and drugs. Herein, we developed a label-free MRI approach for monitoring albumin-based drug delivery systems by directly utilizing the inherent CEST signal of albumin. Our in vitro study showed that both human serum albumin (HSA) and albumin-based nanoparticle Nab-paclitaxel (Abraxane) could generate a strong CEST signal at ~2 ppm. Using this inherent CEST signal, we successfully demonstrated the label-free CEST MRI detection of the tumor uptake and distribution HSA and Nab-paclitaxel in a xenograft mouse model. |
| 2913 | Quantitative ADC as an early imaging biomarker of response to chemoradiation in esophageal cancer | |
1The University of Texas MD Anderson Cancer Center, Houston, TX, United States |
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The goal of the study was to investigate if quantitative ADC can be used as an early imaging biomarker for predicting the treatment response to chemoradiation in esophageal cancer. Using pathological findings as the gold standard, our study demonstrated that the change in quantitative ADC from baseline (before treatment) to interim (two weeks after the initiation of treatment) was highly predictive of whether patients had residual tumors at the end of their treatment. |
| 2914 | Non-gaussian IVIM imaging biomarkers can non-invasively predict the aggressiveness of small papillary thyroid cancers | |
1Medical Physics, Memorial Sloan-Kettering Cancer Center, NEW YORK, NY, United States, 2Radiation Oncology, Washington University in St. Louis, St. Louis, MO, United States, 3Radiology, Memorial Sloan-Kettering Cancer Center, NEW YORK, NY, United States, 4Pathology, NYU Langone Medical Center, NEW YORK, NY, United States, 5Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, NEW YORK, NY, United States, 6Pathology, Memorial Sloan-Kettering Cancer Center, NEW YORK, NY, United States, 7Surgery, Memorial Sloan-Kettering Cancer Center, NEW YORK, NY, United States, 8Medicine, Memorial Sloan-Kettering Cancer Center, NEW YORK, NY, United States |
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There is a need for non-invasive imaging to identify patients with aggressive tumors in papillary thyroid carcinoma (PTC). This study evaluates whether non-gaussian intravoxel incoherent motion (NG-IVIM) DW-MRI has the potential to stratify tumor aggressiveness in PTC. Twenty-four PTC patients underwent pretreatment NG-IVIM DW-MRI at 3T. The apparent diffusion coefficient (ADC), perfusion factor (f), diffusion (D), |
| 2915 | Reproducibility of Quantitative DW-MRI and DCE-MRI of the Breast in the Community Setting: Preliminary Results | |
1Internal Medicine, University of Texas at Austin, Austin, TX, United States, 2Biomedical Engineering, University of Texas at Austin, Austin, TX, United States, 3Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, TX, United States, 4Neuroscience, University of Texas at Austin, Austin, TX, United States, 5US Oncology Network, Austin, TX, United States, 6Seton Medical Center, Austin, TX, United States, 7Austin Radiological Association, Austin, TX, United States |
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Implementation of quantitative DCE-MRI and DW-MRI in the community setting has the potential to impact patient care for a large number of breast cancer patients. Quantitative DW-MRI and DCE-MRI was assessed in phantoms and normal subjects across three sites. In normal subject fibroglandular tissue, the average percent difference in ADC across sites for all subjects was 1.8%, while the average percent difference in the inversion recovery scan and B1- corrected T1 map were 14% and 7.3%, respectively. Overall, the results from the phantom and normal subject scans reveal that quantitative MRI can be successfully implemented in the community setting. |
| 2916 | Ultra-early ADC (apparent diffusion coefficient) footprint successfully detects tumor irradiation and predicts radiotherapy outcome | |
1Radiotherapy Research Unit, Department of Oncology, University of Copenhagen, Herlev and Gentofte Hospital, Herlev, Denmark, 2Department of Radiology, University of Copenhagen, Herlev and Gentofte Hospital, Herlev, Denmark |
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If ultra-early stratification of radiotherapy response was possible it could potentially reduce unnecessary irradiation of normal tissue and improve disease management. In this study repeated diffusion weighted magnetic resonance imaging was conducted along with fractionated radiotherapy in brain metastases patients. It was found that the decrease in the apparent diffusion coefficient (ADC) observed 24 hours after the first radiotherapy fraction may be an indicator of irradiation. Responding patients versus non-responding patients could be differentiated by their corresponding change in ADC seen 48 hours after start of radiotherapy. These findings may have great impact for the emerging hybrid MR – linear-accelerator systems. |
| 2917 | Providing improved reliability of plasma volume fraction estimates for monitoring anti-angiogenic effects in liver metastases with DCE-MRI | |
1CR-UK Cancer Imaging Centre, The Institute of Cancer Research and Royal Marsden Hospital, London, United Kingdom |
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Pharmacokinetic modelling of DCE-MRI data allows characterisation of tumour response to anti-angiogenic therapies by estimating the volume transfer constant Ktrans and the plasma volume fraction Vp. This work assesses the impact on Ktrans and Vp of treatment changes in an early clinical trial cohort by comparing 4 models: Kety, extended Kety (with two lower limits on Vp), and a new model with Vp proportional to Ktrans. When Ktrans is the endpoint of interest, use of the Kety model is sufficient to depict cohort response. If Vp is also of interest, the new model improves the significance of Vp treatment effects. |
| 2918 | Quantitative Evaluation of Treatment Response to Early Concurrent Chemoradiotherapy with Multi-parametric MRI in Esophageal Cancer | |
1Radiology, Zhejiang cancer hospital, hangzhou, People's Republic of China, 2The second clinical medical college, Zhejiang Chinese Medical University, hangzhou, People's Republic of China, 3Life Sciences, GE Healthcare, Shanghai, People's Republic of China, 4Life Sciences, GE Healthcare, hangzhou, People's Republic of China |
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The best dose of concurrent chemoradiotherapy for esophageal cancer exists individual difference because of tumor heterogeneity. The treatment will be more predictable if we can assess the chemoradiotherapy earlier, which will be helpful in early intervention for optimization of treatment plan, treatment time and improvement of overall survival. Multi-parametric MRI is gradually used for evaluating tumor treatment, and provides earlier and more information than conventional MRI. In this study, we used Ktrans value (derived from DCE-MRI) and ADC value (derived from DWI) to assess treatment response after the fifth concurrent chemoradiotherapy in esophageal cancer. |
| 2919 | In vivo OE-MRI quantification and mapping of response to hypoxia modifying drugs Banoxantrone and Atovaquone in Calu6 xenografts | |
1Centre for Imaging Sciences, University of Manchester, Manchester, United Kingdom, 2Manchester Pharmacy School, University of Manchester, Manchester, United Kingdom, 3CRUK/MRC Oxford Institute for Radiation Oncology and Biology, University of Oxford, Oxford, United Kingdom, 4Bioxydyn Ltd, Manchester, United Kingdom, 5Institute of Cancer Sciences, University of Manchester, Manchester, United Kingdom, 6Department of Radiology, The Christie NHS Foundation Trust, Manchester, United Kingdom |
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Oxygen-enhanced MRI (OE-MRI) has shown promise as a technique for quantifying and spatially mapping tumour hypoxia. Here we report the first evidence that OE-MRI signals in perfused tumour can non-invasively track therapy-induced changes in hypoxia in vivo in a tumour model. We show that OE-MRI detects (1) reduction in hypoxia and increase in necrosis induced by the hypoxia-activated cytotoxic prodrug Banoxantrone; and (2) reduction in hypoxia and increase in well oxygenated tumour induced by Atovaquone due to increased oxygen availability. These data support first-in-man use of OE-MRI biomarkers in clinical trials of hypoxia-modifying agents. |
| 2920 | Combining DW- and DCE-MRI for treatment response assessment in patients with esophageal cancer undergoing neoadjuvant chemoradiotherapy | |
1Department of Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands, 2Department of Surgery, University Medical Center Utrecht, Utrecht, Netherlands, 3Department of Radiotherapy, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam |
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Neoadjuvant chemoradiotherapy prior to surgery is often used for treatment of patients with esophageal cancer. Potential benefit could be gained developing a patient tailored treatment, especially for the 29% of the patients who show a pathologic complete response. In this prospective multicenter study it was investigated whether combining DCE- and DW-MRI, which both showed potential for response prediction in previous studies, yields complementary information. It was found that the combination of DCE- and DW-MRI can increase the predictive values and reaches higher ROCAUC. |
| 2921 | MRI biomarkers for PEGPH20-enhanced treatment of pancreatic ductal adenocarcinoma | |
1Radiology, University of Washington, Seattle, WA, United States, 2Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, 3Medical Devices Research, National Inststitute of Health, Bethesda, MD, 4Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN |
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Pancreatic cancer is a devastating disease with poor prognosis. Pancreatic tumor therapy has been ineffective in part because pancreatic tumors have high interstitial fluid pressure (IFP), driven by high hyaluronan concentration, that inhibits penetration of drugs into the tumor. We performed multi-parametric MRI at high resolution to non-invasively assess tumor response in a KPC mouse model to pegylated recombinant hyaluronidase in isolation as well as combined with Gemcitabine. T1 and T2 relaxation as well as diffusion, and 3 dimensional volume measurements were used to characterize the tumors. MR measurements were compared with invasive IFP measurements and histopathological results. |
| 2922 | MRI Efficacy Evaluation of AvastinTM in Combination Temozolomide Therapy using GL261 Tumor Bearing Mice | |
1Laboratory Animal Center, Osong Medical Innovation Foundation, Cheongju, Korea, Republic of |
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The aim of this study was to evaluate of the drug efficacy used by MRI. A mouse were randomly divided into the control and therapy groups for treatment. MRI were performed to compare with two groups and significant differences were observed in the two groups. The volume transfer constant (Ktrans), flux rate constant (kep) and contrast agent (Gd-DOTA-RGD) enhancement were decreased in the therapy group. Apparent diffusion coefficient (ADC) was lower in the control group. Furthermore, histopathologic assessments were in accord with MRI. Based on these results, efficacy evaluation used by MRI can be helped the development of new bio-drug. |
| 2923 | Estimation of Contributions to Z-Spectra from CEST and Magnetization Transfer Contrast from Active and Necrotic/Apoptotic Regions of MDA Tumour Xenografts | |
1Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada, 2Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 3Medical Biophysics, University of Toronto, Toronto, ON, Canada, 4Radiation Oncology, University of Toronto, Toronto, ON, Canada, 5Neurosurgery and Pediatric Neurosurgery, Medical University of Lublin, Lublin, Poland |
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Chemical exchange saturation transfer (CEST) MR imaging has been demonstrated to be able to differentiate active from necrotic/apoptotic regions in MDA tumour xenografts. However, the Z-spectrum reflects not only CEST from dissolved proteins, but also contributions from water saturation and magnetization transfer contrast from semisolid macromolecules. We estimated their individual effect sizes and calculated which significantly contribute to the difference in Z-spectrum amplitude between the two tumour regions. The difference in Z-spectrum amplitude between active and necrotic/apoptotic regions in MDA tumour xenografts is due to the CEST effect with minimal contribution from magnetization transfer contrast and direct water saturation. |
| 2924 | In Vivo 3T Clinical Magnetic Resonance Imaging with a Biologically Specific Contrast Agent in Prostate Cancer: A Nude Mouse Model | |
1Lakehead University, Thunder Bay, ON, Canada, 2Thunder Bay Regional Research Institute, Thunder Bay, ON, Canada, 3Thunder Bay Regional Health Science Center, Thunder Bay, ON, Canada |
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In this study we characterized in vivo a functional superparagmagnetic iron-oxide magnetic resonance contrast agent that effects the T2 relaxation time in MRI. The agent was developed by conjugating Molday Ion Carboxyl-6 (MIC6), with a de-immunized mouse monoclonal antibody (muJ591) targeting prostate-specific membrane antigen (PSMA). We propose this functional contrast agent as a non-invasive method to detect prostate cancer cells that are PSMA positive to provide increased differentiability from surrounding tissues for treatment. PSMA-positive prostate tumours were induced into 20 immunocompromised mice. The functional contrast agent was injected into 14 mice leaving 6 mice as controls. MR imaging was performed on a clinical 3T scanner using different parameters on a MESE sequence to obtain T2 relaxation time values. Tumour size, signal intensity, and T2 relaxation time were obtained pre and post injection and were found to have a lower value for treated mice compared to controls. ICP confirmed the increased level of elemental iron in treated mice tumours compared to controls. H&E staining showed healthy morphology of all tissues collected. The reduction in T2 relaxation time for the functional contrast agent, combined with its specificity against PSMA suggest its potential as a biologically-specific MR contrast agent. |
| 2925 | Tumor Progression Monitoring with Hyperpolarized 13C Exchange Spectroscopy in Transgenic Adenocarcinoma of Mouse Prostate Treated with Androgen Deprivation Therapy | |
1Department of Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, 2UC Berkeley-UCSF Graduate Program in Bioengineering, UC Berkeley and UCSF, San Francisco, CA, United States |
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Hyperpolarized 13C MR imaging provides valuable enzyme-kinetic information for investigating disease metabolism. In this work, a new exchange spectroscopic imaging method was applied to a preclinical cancer treatment study and the metabolic information provided by this new method agreed with and proved additional quantitative kinetic metrics over traditional Response Evaluation Criteria in Solid Tumors (RECIST) measures. |
| 2926 | In vivo follow-up of colorectal cancer on mice model using endoluminal MRI | |
1Univ Lyon, INSA‐Lyon, Université Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, Lyon, France, 2Institut de Génomique Fonctionnelle de Lyon, Université de Lyon 1, UMR 5242 CNRS, Ecole Normale Supérieure de Lyon, Lyon, France, 3LTSI; INSERM U642; Université Rennes 1, Rennes, France, 4Hôpital Régional Universitaire de Tours - Service hépato-gastroentérologie, Tours, France |
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For 6 months, 32 mice, chemically treated to induce colorectal cancer, were followed with endoluminal MRI using dedicated endorectal coils. Based on high spatial resolution T1-weigthed images and T1-maps, quantified parameters (colon wall thickness and T1 relaxation time) were measured at each stage of the pathology from healthy tissues to cancer through inflammation. The colon wall thickness was found to be reliable in assessing early stages of the pathology (inflammation from infiltration), where the intrinsic contrast T1 time parameter was reliable for discerning infiltration from tumors. The two biomarkers provide complementary information in the characterization and staging of colorectal cancer. |
| 2927 | Combined DCE-MRI and immunohistochemical analyses of cervical cancer xenografts reveal differences in the physiological background of prognostic image parameters derived from the Tofts and Brix model | |
1Department of Core Facilities, Oslo University Hospital, Oslo, Norway, 2Department of Radiation Biology, Oslo University Hospital, Oslo, Norway |
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The Tofts and Brix parameters Ktrans and ABrix , derived from dynamic contrast-enhanced MRI (DCE-MRI), have been suggested as potential markers of hypoxia. This phenotype is associated with poor outcome in cervical cancer treated with chemoradiotherapy. In this study, DCE-MRI was combined with immunohistochemical analysis of cervical cancer xenografts, to better understand the physiological background and prognostic potential of the parameters. Through correlations with hypoxic fraction, vascular and cellular densities, derived from pimonidazole, CD31 and hematoxylin staining of tumor sections, respectively, it was shown that ABrix could be the preferred DCE-MRI parameter for predicting hypoxia related treatment resistance in cervical cancer. |
| 2928 | Unraveling osteosarcoma tumor heterogeneity using MRI-defined tumor habitats | |
1Imaging and Metabolism, Moffitt Cancer Center, Tampa, FL, United States |
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We explore heterogeneity in osteosarcoma using imaging “habitats”, which identify different physiological subregions by MRI. We propose a method to establish the relationship between the microenvironmental of a habitat by relating histology to MRI. Computational image analysis was used to cluster tumor habitats with a 3D printing approach to co-register MR images with histology and immunohistochemistry. Compared with H&E and the CA-9, we found that cellular morphology and density were in concordance with the clustered habitats, although there are subtle differences between histology and MRI slices. Thus, identifying tumor habitats in osteosarcoma using multiparametric MRI is feasible and promising. |
| 2929 | Multi-parametric MRI of glioblastoma invasion quantitative evaluation using histological stacks | |
1Glasgow Experimental MRI center, University of Glasgow, Glasgow, United Kingdom, 2Institute of Cancer Sciences, University of Glasgow, Glasgow, United Kingdom, 3School of medicine, dentistry and nursing, University of Glasgow, Glasgow, United Kingdom |
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We perform a quantitative histological evaluation of a range of MRI techniques in their ability to probe glioblastoma invasion in a mouse model. Using 3-D histological stacks co-registered with MRI slices allows to achieve high values in Dice, sensitivity and specificity tests (>90%). This approach enables to go beyond the standard evaluation tests, performing direct voxel-to-voxel comparison between MRI and histology, and facilitating the development of multi-parametric analysis models. We also identified promising methods for detecting low tumour concentration regions at the invasion limits. |
| 2930 | Multi-parametric MRI assessment of tumor progression in a mouse model of pancreatic cancer | |
1Department of Radiology, University of Washington, Seattle, WA, United States, 2Center for Industrial and Medical Ultrasound Applied Physics Laboratory, University of Washington, Seattle, WA, United States, 3Department of Medicine, University of Washington, Seattle, WA, United States |
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Pancreatic ductal adenocarcinoma (PDAC) is one of the most common forms of lethal human cancers with poor prognosis. Diagnosis is made usually late in tumor development. There is a dire need to develop sensitive non-invasive biomarkers to diagnose and monitor tumor progression and its associated pathological features. We propose to use multi-parametric MRI (mpMRI) to monitor tumor progression in a genetically engineered KPC mouse model that recapitulates human PDAC. Using mpMRI, we demonstrate that there is a significant correlation between increase in pancreatic tumor volume, Magnetization transfer ratio (MTR), apparent diffusion coefficient (ADC), and chemical exchange saturation transfer (CEST) imaging. |
| Exhibition Hall | Thursday 13:00 - 15:00 |
| 2931 | Highly Accelerated 31P MRSI of Human Calf Muscles combining Flyback Echo Planar Spectroscopic Imaging (EPSI) and Compressed Sensing | |
1Biomedical Engineering, McMaster University, Hamilton, ON, Canada, 2Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada |
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Very long acquisition times is the most important limitation against performing 31P magnetic resonance spectroscopic imaging (MRSI) in clinic environments. To overcome this limitation we show the feasibility of implementing in vivo highly accelerated 31P-MRSI combining flyback echo planar spectroscopic imaging (EPSI) and compressed sensing (CS) achieving a 12x12 matrix over a 24 cm field of view (FOV) in less than 6 minutes. Due to the denoising nature of CS the resultant SNR was also improved using this approach. |
| 2932 | Mapping the exchange kinetics of high-energy phosphates in the human calf muscle by direct 31P MRSI at 7T | |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany |
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31P MRS allows the non-invasive observation of high-energy phosphate turnover in vivo. A model incorporating the effects of exchange processes onto the transverse steady-state magnetization was derived, which allows the direct estimation of relaxation rates from signal intensities in MRSI datasets. Multiple 31P MRSI datasets with different excitation parameters of four healthy were evaluated. Spatially-resolved turnover rates of high-energy phosphates could be estimated and are in agreement with literature values proving feasibility of the proposed approach. |
| 2933 | Measurement of human cardiac intracellular pH in vivo using long TR 31P-MRS with adiabatic excitation at 7T | |
1Oxford Centre for Clinical MR Research (OCMR), RDM Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom, 2Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia |
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Determination of human cardiac intracellular pH using 31P-MRS is challenging as the resonance frequency of Pi is concealed by a close resonating 2,3-DPG signal originating from blood. Common short TR and low-flip angle scan used for cardiac 31P-MRS increase the effective SNR/time, but can additionally suppress the Pi signal intensity. We have investigated the feasibility of detecting cardiac Pi and calculating intracellular pH of human heart using long TR 3D-CSI examination with adiabatic excitation at 7T. Comparison to short TR acquisition was performed using interleaved TR measurements. We report robust and repeatable detection of Pi signal in 100% of subjects. |
| 2934 | Phosphocreatine T1 in human gastrocnemius muscle at 7T increases during exercise, measured by localized 31P MRS with progressive saturation | |
1Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, 2Department of Internal Medicine III, Medical University of Vienna, Austria |
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Alterations in T1 have implications on the physiological interpretation of dynamic high-energy phosphate data. Progressive saturation during rest-exercise-recovery experiments was used to simultaneously quantify PCr depletion, recovery and T1 values. The data were acquired using localised 31P MRS in human gastrocnemius. Apparent T1 values increased from 5.0 ± 0.4 s at rest to an average value of 5.8 ± 0.5 s during exercise, with a peak in early exercise and returning towards baseline values before exercise was ceased. These alterations may be explained by changes in the chemical exchange rates of PCr with ATP and Pi. |
| 2935 | Dynamic 31P spectroscopy during superimposed electrical muscle stimulation and volitional contraction for enhanced metabolic response in the skeletal muscle | |
1Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland, 2Department of Biomedical Engineering, University of Basel, Basel, Switzerland, 3Pediatric Neurology, UniversitätsKinderspital beider Basel (UKBB), Basel, Switzerland |
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Dynamic 31P spectroscopy of the skeletal muscle can provide useful insight into its energy metabolism. However, in order to see dynamic changes in metabolites, a minimum threshold of physical exercise is necessary. In this work, we present a system that uses electrical muscle stimulation superimposed to volitional muscle contraction in order to enhance the metabolic response of the muscle in the same workload condition. This method can have potential application to patients that are unable to voluntarily exert sufficient work for a dynamic spectroscopy investigation. |
| 2936 | In vivo 31P spectroscopy of ATP levels during a fructose challenge in the liver at 7T | |
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Spinoza Centre, Amsterdam, Netherlands, 3Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, 4Radiology, UMC Utrecht, Utrecht, Netherlands, 5MR Coils, Zaltbommel, Netherlands |
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The standard evaluation of detecting liver parenchyma is invasive liver biopsy, while MRS is a non-invasive measurement to monitor metabolites. Using 31P spectroscopy it is possible to follow metabolic changes in the liver and the functionality of the liver during fructose uptake by measuring ATP levels. Going to ultra-high field strength, we are more sensitive to ATP levels and are able to use more localized MRS sequences (e.g. 3D CSI). We have shown we are able to monitor ATP levels during fructose uptake in vivo in the liver at 7T and see a decrease in ATP levels during the uptake. |
| 2937 | Chronic liver disease in developing brain: an in vivo longitudinal and multiparametric study using 31P MRS, 31P Magnetization transfer and 1H MRS | |
1Laboratory for Functional and Metabolic Imaging, EPFL, Lausanne, Switzerland, 2High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, 3Centre d’Imagerie Biomedicale (CIBM), EPFL, Lausanne, Switzerland |
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Chronic liver disease (CLD) induces irreversible brain alterations, especially in children, probably linked with oxidative stress and energy metabolism perturbations. Our aim was to use combination of NOE enhanced and 1H-decoupled 31P-MRS, 31P-saturation transfer experiment (to estimate mitochondrial creatine kinase rate) and 1H-MRS to study the effect of CLD on developing brain. Our results show significantly reduced kATP→PCr and fluctuating NAD+/NADH ratio indicating perturbation in mitochondrial function, possibly induced by oxidative stress. In addition, altered phospholipid metabolism was observed. |
| 2938 | 31P MR spectroscopy of peripheral artery occlusive disease patients with and without diabetes | |
1MR-unit, Institute for Clinical and Experimental Medicine, Prague, Czech Republic, 2First Faculty of Medicine, Charles University, Prague, Czech Republic, 3Transplant Surgery Dept., Institute for Clinical and Experimental Medicine, Prague, Czech Republic, 4Dept. Diabetology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic, 5Dept. Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic |
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Reduced blood supply limits the oxidative muscle metabolism and causes acidosis due to anaerobic glycolysis. Similar results were found in patients with peripheral artery occlusive disease (PAOD) in which chronic ischemia causes claudication and restricts walking distance. 31P MR spectroscopy of calf muscles of healthy controls and patients show that PAOD significantly influences muscular metabolism which is reflected in dynamic parameters of PAOD patients. The effect of diabetes is significantly pronounced in diabetic PAOD patients at rest compared to controls and PAOD patients without diabetes. |
| 2939 | Exogenous NAD+ Enhances Energy Metabolism in Healthy Rat Brains | |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States |
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Decline in NAD+ availability is tightly linked to many neurological disorders. Our recent study also revealed age dependences of intracellular NAD+, NADH and total NAD concentrations in healthy human brains. Accumulating evidences have shown that the cellular NAD+ could serve as a therapeutic target for treating metabolic or age-related neurological diseases and promoting longevity. Therefore, to investigate the effect of exogenous NAD+ on intracellular NAD metabolism, the in vivo 31P-MRS NAD imaging assay developed in our lab was applied in normal rat brains at 16.4 T. Significant increases of cerebral α-ATP, total NAD and NAD+ levels were observed after the intra-peritoneal infusion of exogenous NAD+. This study not only demonstrates the feasibility of using exogenous NAD+ to enhance cerebral ATP and NAD metabolisms, but also provides an opportunity to better understand the roles of NAD metabolism in health and age-related disease. |
| 2940 | Ferumoxytol as a blood-pool T2 relaxation agent for 7T phosphorus spectroscopy | |
1Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom, 2Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, United Kingdom, 3Department of Physics, University of Oxford, Oxford, United Kingdom |
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Ferumoxytol is a licensed carbohydrate-coated, superparamagnetic iron oxide nanoparticle indicated in the treatment of anaemia. We show that, in contrast to other agents, it predominantly reduces T2, is confined to the blood pool for >1 hour post administration, and therefore could improve the efficiency of saturation pulses that aim to remove the 2,3-diphosphoglycerate signal from blood. This proof-of-principle study shows that Ferumoxytol could enable inorganic phosphate detection in vivo, and hence the determination of pH. |
| 2941 | Measuring lactate dehydrogenase activity with proton detected 13C hyperpolarization | |
1Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom |
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Dissolution Dynamic Nuclear Polarized NMR (dDNP NMR) is a promising new tool for assessing metabolism in vivo. The signals of the hyperpolarized substrate and its downstream metabolites are usually detected by direct 13C observation. Here we demonstrate an effective way to repetitively transfer hyperpolarization via indirect couplings from [1-13C] to [3,3,3-1H3] in [1-13C] lactate formed from hyperpolarized [1-13C] pyruvate. The changes in the hyperpolarized [3,3,3-1H3] lactate peak were fitted to a kinetic model. The method sets the stage for dynamic hyperpolarized 1H imaging. |
| 2942 | Automated Kinetic Modeling of Hyperpolarized 13C Metabolism in Human Brain Tumors | |
1UCSF, San Francisco, CA, United States |
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Methods for dynamic spectroscopic imaging of hyperpolarized (HP) 13C substrates are rapidly evolving and accessible tools are required for reconstructing the data and for validating quantitative kinetic models. This study presents processing tools for automatic analysis of data from dynamic HP 13C experiments. The methods were implemented in the open-source SIVIC software package and applied to the fitting of data from a human brain tumor trial to derive metabolic Kpl maps. |
| 2943 | Analyzing Reaction Dynamics With Hyperpolarized 13C-NMR | |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States |
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In this study we use hyperpolarized 13C-NMR to probe the dynamics of the decarboxylation reaction of pyruvate via H2O2, commonly used to produce hyperpolarized bicarbonate. Using this method we are able to observe and quantify the dynamics of the intermediate state, 2-hydroperoxy-2-hydroxypropranoate, which has never before been directly observed at room temperature, as well as characterizing a previously overlooked side reaction between the products and reactants of the decarboxylation reaction. This study serves as a template for how to use hyperpolarized 13C NMR to study the dynamics of innumerable other organic reactions with polarizable substrates. |
| 2944 | 2D Heteronuclear Single-Quantum Coherence MR spectroscopy for in vivo detection of 13C-labeling in rat brain during simultaneous infusion of 13C-labeled substrates | |
1Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States, 2Department of Psychiatry, Yale University, New Haven, CT, United States |
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We adopted a 2D heteronuclear single-quantum coherence (HSQC) MR spectroscopy method to detect in vivo 13C isotopomers in rat brain through exploiting the high sensitivity of 1H MRS. This method allows for in vivo detection of unique 13C-labeling patterns in brain metabolite pools during simultaneous infusion of different 13C-labeled substrates. We demonstrated that high-quality 2D HSQC MR spectra can be acquired in vivo in a time-resolved manner from rat brain during simultaneous infusion of [U-13C6]-glucose and [2-13C]-acetate. This method can be used to study with high accuracy neuronal and glial metabolism, and the contribution of alternate substrates to brain energy metabolism. |
| 2945 | Localized, indirect 1H-[13C] MRS measurement of glutamate and glutamine 13C-labeling in frontal cortex of human brain at 4 Tesla. | |
1Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States, 2Department of Endocrinology, Yale University, New Haven, CT, United States |
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We present an indirect 1H-[13C] MRS detection method (selective proton-observed, carbon edited (selPOCE) that can be used in the frontal lobe of human brain, allows for separation of overlapping glutamate (Glu) and glutamine (Gln) peaks and provides well-defined spatial localization of the 13C-signal. The method was successfully implemented at 4 Tesla and allowed for the selective detection of 13C-labeling in Glu and Gln in a timely manner (15 min), indicating that the selPOCE can be used for quantitative studies of brain energy metabolism and neurotransmission in a relatively small volume localized in the human frontal lobe. |
| 2946 | Protocol for investigating in vivo Glucose Metabolism in Human Breast Cancer by 13C MRS at 7T | |
1Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 2Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 3Philips Medical Systems, Cleveland, OH, United States, 4Biomedical Engineering, Texas A&M University, TX, United States, 5Electrical Engineering, Texas A&M University, TX, United States, 6Chemistry, University of Texas at Dallas, TX, United States, 7Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States |
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Upregulated glucose uptake in cancer is often observed and can be monitored with a radiolabeled analogue of glucose, 18FDG, with detection by PET, however, a well-known constraint is its ionizing radiation. Additionally, except for the trapping of that glucose analogue, PET does not provide information about subsequent glucose metabolism. Here, we demonstrated the feasibility of a simple glucose infusion protocol that allows detection of glucose oxidation in human breast cancer in vivo via 7T 13C MRS. The [U-13C]glucose infusion is performed outside of the magnet making the protocol significantly more suitable for patients compared to previous approaches that required prolonged 13C substrate infusions inside the scanner. |
| 2947 | Human In Vivo 25Mg Spectroscopy and Imaging at 7T | |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Institute of Radiology, University Hospital Erlangen, Erlangen, Germany |
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25Mg spectroscopy and imaging were performed for the first time in vivo. T1 and T2* of 25Mg were evaluated in model solutions and T2* was additionally estimated in vivo for the human calf. 25Mg spectroscopy of an MgCl2 model solution exhibits a single resonance attributed to free 25Mg2+ ions, while in vivo spectroscopy of a human calf displays an additional resonance possibly attributable to bound 25Mg. Phantom and in vivo 25Mg imaging of the human calf were performed with a voxel size of 25×25×25 mm3. |
| 2948 | Investigation of Lithium Distribution in the Rat Brain ex vivo using Lithium-7 Magnetic Resonance Imaging at 17 Tesla | |
1INSERM UMR-S 1144, Universités Paris-Descartes & Paris-Diderot, Paris, France, 2Neurospin, CEA, Université Paris-Saclay, Gif-sur-Yvette, France, 3APHP, GH Saint-Louis-Lariboisière-Fernand Widal, Laboratoire de Toxicologie biologique, Paris, France, 4Inserm UMR-S 894, Université Paris-Descartes, Paris, France, 5APHP, GH Saint-Louis-Lariboisière-Fernand Widal, Réanimation Médicale et Toxicologique, Paris, France |
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Lithium (Li) is the first-line mood stabilizer to treat bipolar disorder patients. However, its mechanisms of action and transport across the blood-brain barrier remain poorly understood. In this study, we aimed at mapping ex vivo the cerebral Li distribution of rats treated for 28 days with Li2CO3 using 7Li-MRI at 17.2 Tesla. Using a phantom replacement approach, MRI-derived Li concentrations were calculated and validated by comparison to inductively coupled plasma-mass spectrometry (ICP-MS) measurements. Lithium distributions were uneven (normalized lithium content ranging from 0.7 to 1.4) and symmetrical with consistently lower concentrations in the metencephalon and higher ones in the cortex. |
| 2949 | Density-Adapted k-Space Sampling Technique for Fast Relaxing Chlorine-35 Nuclei at 9.4 T | |
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, 2MR-Imaging and Spectroscopy, Universty of Bremen, Bremen, Germany |
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Chloride Cl- as the most abundant anion in mammals is a vital component of biophysical regulatory processes. 35Cl MRI has the potential to visualise Cl- homeostatic changes during stroke, in tumors and in ionic regulatory diseases. This study aimed at demonstrating the advantages of implementing density-adapted k-space sampling to overcome the instrinsically low SNR associated with 35Cl MRI. We showed that density-adapted k-space sampling yielded distinctively visible improvement of image quality as well as quantitative SNR gain in phantoms with very fast bi-exponential T2* relaxation over conventional radial sampling. |
| 2950 | Chemical Shift Encoded (CSE) Image Reconstruction for Spectral Selection in Fluorine-19 MRI | |
1Medical Physics, University of Wisconsin - Madison, Madison, WI, United States, 2Radiology, University of Wisconsin - Madison, Madison, WI, United States, 3Electrical and Computer Engineering, University of Wisconsin - Madison, Madison, WI, United States, 4Radiology, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 5Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States |
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In preclinical applications, the high specificity of quantitative 19F MRI may be compromised by non-negligible signal contributions from fluorinated anesthetics (e.g. isoflurane). Here, we demonstrate the feasibility of chemical shift encoding (CSE) with multi-resonance fluorine signal modeling and least-squares estimation image reconstruction for 19F MRI. We optimize noise performance (NSA) and use a 3D spoiled gradient-echo acquisition to separate signal contributions from perfluoro-15-crown-5-ether (PFCE) and isoflurane. The method is tested in mixed PFCE/isoflurane phantoms showing effective signal separation. The CSE reconstruction removes isoflurane signal contributions in 19F MR images of PFCE in vivo, potentially reducing errors in 19F concentration quantification. |
| 2951 | High Resolution Dynamic 31P-MRSI of Ischemia-Reperfusion in Rat Hindlimb at 9.4T Using SPICE | |
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States, 3Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 4Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 5Gordon Center for Medical Imaging, NMMI, Department of Radiology, Massachusetts General Hospital, MA, United States, 6Department of Radiology, Harvard Medical School, MA, United States, 7Department of Radiology, Case Western Reserve University, Cleveland, OH, United States, 8Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, United States |
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Dynamic 31P-MRSI serves as a non-invasive tool to assess mitochondrial oxidative capacity in skeletal muscle during ischemia-reperfusion or exercise-recovery. However, 31P-MRSI with high spatial resolution requires long acquisition times which render dynamic measurements impractical. In this study, we adapted a recently proposed low-rank tensor-based method for high-resolution dynamic 31P-MRSI in preclinical studies. We present results from an in vivo ischemia-reperfusion experiment on a rat hindlimb with 15 s nominal temporal resolution and 0.75×0.75×1.6 mm3 nominal spatial resolution, demonstrating the potential of the method for assessing mitochondrial function in different muscle types in small animal models. |
| 2952 | Dynamic Oxygen-17 MR Imaging with Golden-Ratio-Based Radial Sampling and k-Space-Weighted Image Reconstruction | |
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, 2Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States, 3Department of Chemistry, Case Western Reserve University, Cleveland, OH, United States, 4Department of Radiology, Case Western Reserve University, Cleveland, OH, United States, 5Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, United States |
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This study aimed at developing a 3D dynamic oxygen-17 (17O) MR imaging method to delineate the kinetics of 17O-water uptake and washout in mouse brain with glioblastoma at high temporal and spatial resolution. A 3D imaging method using a stack-of-stars golden-ratio-based radial sampling scheme was combined with k-space weighted image reconstruction to improve the temporal resolution with preserved spatial resolution. The proposed method achieved a temporal resolution of 7.56 s with a voxel size of 5.625 μL in mouse brain at 9.4T. It can also be used to image cerebral oxygen consumption rate in 17O inhalation studies. |
| 2953 | Measurement of CMRO2 in conscious rat with in vivo 17O MRS at 16.4T | |
1CMRR, Radiology, University of Minnesota Medical School, Minneapolis, MN, United States, 2Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, United States |
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In this study we performed dynamic in vivo 17O MRS measurements in conscious and isoflurane-anesthetized rat during inhalations of 17O2-enriched gas at ultra-high field of 16.4T, ultimately to compare the relation between CMRO2 and brain condition. |
| 2954 | Quantification of Cerebral Metabolic Rates of 17O-Labeled Glucose in Mouse Brain with Dynamic 17O-MRS | |
1Dept. of Radiology, Medical Physics, Medical Center-University of Freiburg, Germany, Freiburg, Germany, 2German Cancer Consortium (DKTK), Heidelberg, Germany, Heidelberg, Germany, 3German Cancer Research Center (DKFZ), Heidelberg, Germany, Heidelberg, Germany, 4NUKEM Isotopes Imaging GmbH, 5Bruker BioSpin GmbH, 6Faculty of Medicine, University of Tübingen, Germany, 7Institute of Physics, University of Freiburg, Germany |
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We studied the chemical exchange kinetics of 17O-labeled glucose at the C1 and the C6 position with dynamic 17O-MRS. A profile likelihood analysis is performed to determine identifiability and confidence intervals of the metabolic rate CMRGlc. The exchange experiments confirm that the C6-17OH label is transferred via glycolysis exclusively by the enzyme enolase into the metabolic end product H217O, while C1-17OH ends up in water via direct hydrolysis as well as via glycolysis. From H217O-concentration time-courses cerebral metabolic rates of CMRGlc = 0.05‑0.08 µmol/g/min are obtained which are in of the same order of magnitude as 18F-FDG PET. |
| 2955 | Direct Partial Volume Corrected CMRO2 Determination: Simulation assisted Dynamic 17O-MRI | |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Institute of Radiology, University Hospital Erlangen, Erlangen, Germany |
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A dynamic 17O-MRI inhalation experiment enables localized mapping of the cerebral metabolic rate of oxygen consumption (CMRO2) in the human brain via H217O quantification. These functional information are tissue viability parameters and can help studying the brain metabolism. In 17O-MRI, accurate quantification and CMRO2-determination is severely biased by partial volume effects caused by low spatial resolution and fast transverse relaxation. A human brain-simulation providing realistic dynamic 17O-data was used to evaluate the performance of a partial volume correction algorithm at different temporal resolution. Findings were then adapted to an in-vivo 17O-MRI inhalation experiment which was conducted in a healthy volunteer. |
| 2956 | Proof of concept for the separation of free and bound sodium in human brain through two-TE acquisitions at 3T | |
1Radiology, New York University, New York, NY, United States, 2Siemens Medical Solutions USA, New York, NY, United States |
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In human brain, intracellular sodium ions (Na+) are in slow and restricted motion due to their binding to negatively-charged macromolecules while their extracellular counterparts are in fast and unrestricted motion. This difference in motion properties leads to changes in bi-exponential transverse decay of free and bound sodium ions, which have been explored previously as a means to separate free and bound sodium. In this study, a new approach is proposed to separate free and bound sodium using single-quantum sodium images, without the SNR and SAR limitations as encountered in the triple-quantum filtering approach. |
| 2957 | 3D Multi-Echo Radial Imaging of $$$^{23}$$$Na (3D-MERINA) for time-efficient multi-parameter mapping | |
1Electrical & Electronic Engineering, University of Melbourne, Melbourne, Australia, 2Siemens Healthcare, Melbourne, Australia, 3Anatomy & Neuroscience, University of Melbourne, Melbourne, Australia, 4joint senior authors |
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Challenging imaging characteristics (low SNR, fast bi-exponential decay) have so far limited the application of 23Na-MRI in clinical environments. This work presents 3D Multi-Echo Radial Imaging of 23NA (3D-MERINA), a time-efficient acquisition protocol from which multiple parameter maps (sodium-density, T2*slow and T2*fast, free 23NA) can be derived in a single acquisition. Phantom and in-vivo measurements were analysed for the evaluation of parameter mapping and the inference of tissue characteristic based on decay behaviour. All parameters were acquired in a single sodium-density-weighted acquisition under relatively low SAR. Future investigation will exploit 3D-MERINA for SQF-SNR enhancement and the detection of MQF contrasts. |
| 2958 | Elliptically-shaped 1Tx4Rx Coil for 23Na Body MRI at 7T | |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Institute of Radiology, University Hospital Erlangen, Erlangen, Germany, 3Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany |
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Up to now, only a few abdominal 23Na-MRI studies have been performed at 7T. In this work a 23Na body coil for 7T was enhanced. To achieve an improved homogeneity in the transmit field and in the receive sensitivity, transmit phase settings were optimized and four separate receive channels were implemented. Field distributions in a phantom were obtained for the original and the enhanced configuration. Both setups were applied to the human chest and abdomen. Transmit and receive homogeneity are markedly improved for the enhanced setup. Improvements for in-vivo image quality are especially visible in the contour of the body. |
| 2959 | In Vivo Double Quantum Filtered 23Na Imaging of Human Skeletal Muscle | |
1Institute of Radiology, University Hospital Erlangen, Erlangen, Germany |
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Double quantum filtered sodium (23Na) MRI represents a way to examine the degree of tissue microstructure but suffers from low signal intensity and therefore long acquisition time. In this work we developed an efficient simultaneous acquisition scheme of single and double quantum images and determined the optimum acquisition parameters for human skeletal muscle. The feasibility of double quantum filtered 23Na images of human lower leg at 3T was shown. |
| 2960 | Variable Flip Angle Pipeline for in vivo Sodium Concentration Measurements (VaSCo) | |
1NeuroSpin, CEA, Paris Saclay University, Gif-sur-Yvette, France, Paris, France, 2Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, USA, 3Aachen University Clinic, Neurology Department, Aachen, Germany |
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This work presents a new method to measure Sodium concentration in human tissue using the Variable Flip Angle method with optimized acquisition parameters. Healthy volunteers were scanned and measures provided concentration values and T1 values in agreement with litterature values. |
| 2961 | Optimizing the precision and accuracy of sampling schemes for T2* quantification of the fast biexponential decay of sodium MRI | |
1Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 2Institute of Radiology, University Hospital Erlangen, Erlangen, Germany |
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Sodium imaging is mainly performed with spin-density weighted sequences to quantify tissue sodium concentration. However, relaxation weighting can add additional specific information. We pursue appropriate sampling for low SNR and fast biexponential decay. The accuracy and precision of typical T2* measurements is determined for different sampling schemes by simulation and phantom measurements. We developed a dedicated sampling scheme for brain parenchyma employing numerical optimization. The results suggest that averaging is preferable to increase reliability compared to denser temporal sampling. In-vivo comparison confirmed the advantage of the optimized patter with increased separation of the decay components. |
| 2962 | Influences of MRI proton contrast agent on sodium MRI at clinical 3T field strengths | |
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany |
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Sodium MRI enables to measure tissue sodium content (TSC) non-invasively, which provides additional cellular information and can serve as biomarker e.g. for tumor imaging. Thus, sodium imaging can complement standard clinical protocols. Many clinical routine protocols include perfusion scans with proton contrast agents but the influences on sodium relaxation times and therefore quantification accuracies of TSC are unknown. Our preliminary results showed no significant changes in sodium T1 and only small reductions of T2 with clinically relevant concentrations of contrast agents. Therefore, proton contrast agents are not expected to influence the TSC quantification in UTE sodium sequences. |
| 2963 | Relaxation in Simultaneously Acquired Single and Triple Quantum Filtered Sodium Imaging | |
1Institut 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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Sodium imaging delivers valuable information about metabolism and disease. The spin dynamics of sodium are significantly impacted by the environment of the nuclei, multiple quantum coherences might develop via the quadrupole interaction. This allows imaging with multi quantum filters (MQF) to achieve weightings towards different sodium compartments. MQF sodium signals are detected with three consecutive RF pulses, by placing a readout train between the first and second RF pulse, a fully quantitative characterisation of relaxation properties in a two-compartment model is possible from measurements within a single sequence. |
| 2964 | Sodium MRI of the thyroid gland at 7 tesla | |
1Imaging Division, University Medical Center, Utrecht, Netherlands, 2Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany, 3Institute of Radiology, University Hospital Erlangen, Erlangen, Germany, 4Biomedical Image Analysis, Eindhoven University of Technology, Eindhoven, Netherlands |
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This work shows the potential of sodium imaging of the thyroid gland in vivo at 4mm isotropic resolution integrated to 1H imaging. An optimized setup combined with tuned sequences and B1 corrections enables quantitative sodium mapping of the thyroid gland and its surrounding tissue. The thyroid gland has the highest concentration of sodium in this part of the neck, estimated to be 64.5 mmol/L in vivo. Sodium imaging might open up the detection of (lymph node) metastases of thyroid cancer, as they are expected to exceed the healthy concentration of sodium detected in the head and neck region. |
| 2965 | Quantitative Sodium MRI of the Human Kidney at 3T | |
1Radiology, University of Cambridge, Cambridge, United Kingdom, 2University of Cambridge, Cambridge, United Kingdom, 3MR Research Center, Aarhus University, 4Cambridge Institute, Cancer Research UK, 5MRI, Addenbrooke's Hospital, Cambridge, United Kingdom |
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Imaging of the renal system with sodium MRI has gained interest in the past few years, especially in using the technique to quantify, and assess for, changes in the cortio-medullary sodium gradient. The main hindrance for previous work has been the lengthy scan time required to obtain sodium images. However, utilizing a 3D cones trajectory, the work presented here shows good detection of the cortio-medullary sodium gradient, in a clinically feasible scan time, in a sample of six healthy controls. |
| Exhibition Hall | Thursday 13:00 - 15:00 |
| 2966 | Metabolite levels in hippocampus and temporal lobe using long TE magnetic resonance spectroscopic imaging for epilepsy diagnostics | |
1Radiology and Medical Informatics, University of Geneva, Geneva, Switzerland |
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The aim of this study is to obtain normative reference 1H-MRSI data on the ratio of total NAA to total Cho in healthy subjects for subsequent use for clinical diagnosis of epileptic patients. Furthermore, we studied the effect of voxel content, primarily white matter and regional gray matter on metabolic levels. |
| 2967 | 7T MRSI Identifies Neuronal and Axonal Injury in a Limbic Network in MRI Negative Veterans with mTBI and PTSD | |
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2Neurology, University of Pittsburgh, Pittsburgh, PA, United States, 3Neurology, Pittsburgh Veterans Administration Medical Center, PA, United States, 4Biostatistics, Pittsburgh Veterans Administration Medical Center, PA, United States |
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Following mild traumatic brain injury (mTBI) many veterans continue to experience persistent symptoms despite an absence of significant findings on conventional MRI. In this study we acquired MRSI and volumetric data from veterans with a history of mTBI and PTSD, healthy age matched controls and veterans with PTSD without a history of mTBI. Data was acquired from the hippocampus (single slice MRSI) and cingulate (multiband MRSI). Significant declines in NAA/Ch were seen in the hippocampal formation in comparison to healthy controls and veterans with PTSD. Further, reductions in hippocampal NAA/Ch were statistically correlated with reductions in NAA/Ch from the cingulate |
| 2968 | Lactate is associated with tumour grading in breast cancer – An ex vivo study on whole breast tumours using multiple quantum coherence (MQC) MRS | |
1Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, United Kingdom, 2Pathology Department, Aberdeen Royal Infirmary, Aberdeen, United Kingdom, 3School of Medicine, University of Aberdeen, Aberdeen, United Kingdom, 4Breast Unit, Aberdeen Royal Infirmary, Aberdeen, United Kingdom, 5Strathclyde Institute of Pharmacy and Biological Sciences, Glasgow, United Kingdom |
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Breast cancer is associated with increased lactate production in tumour, known as Warburg effect, that is postulated to enhance cancer cell survival advantage and invasiveness. However, current evidence, mainly based on xenografted animal models or biopsy results, remains controversial, where non-identical biological environments are compared to humans, or partial sampling error may play a role. We therefore examined the role of lactate concentration in whole human breast tumour, and hypothesised that there is a difference in lactate concentration between grade II and III breast cancer. To extract lactate under overwhelming lipid signal, MQC MRS was optimised for robust measurement. |
| 2969 | Assessment of Response to Radiation Therapy Using High-Resolution Proton MRSI in Soft Tissue Sarcoma Patients | |
1Gordon Center for Medical Imaging, Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 2Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 3Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, 4Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, People's Republic of China |
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As the recent rapid development of radiation therapy techniques glowingly facilitate an individualized adaptive radiation therapy (RT), the roles of imaging as a tool to assess the early treatment response to RT or to tailor the treatment volume are becoming important. Conventional structural MR images have limited specificities in delineating and differentiating between residual/recurrent tumor and treatment effects (e.g., edema, inflammation, and radiation necrosis). This work presents a pilot study to assess response to RT in soft tissue sarcoma (STS) patients using a recently proposed rapid high-resolution MRSI method: SPectroscopic Imaging by exploiting spatiospectral CorrElation (SPICE). |
| 2970 | Towards in vivo neurochemical profiling of multiple sclerosis with MR spectroscopy at 7 Tesla: Cross-sectional assessment of frontal-cortex glutathione, GABA, and glutamate in individuals with relapsing-remitting and progressive multiple sclerosis | |
1Biomedical Engineering, Columbia University School of Engineering and Applied Science, New York, NY, United States, 2Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, United States, 3Neurology, Yale University School of Medicine, New Haven, CT, United States, 4Radiology, Columbia University School of Engineering and Applied Science, New York, NY, United States |
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Multiple sclerosis (MS) is an autoimmune disease that damages the central nervous system and affects an estimated 2.3 million people worldwide. One potential key to understanding MS is investigating the metabolic distinctions between its relapsing-remitting (RR-MS) and progressive courses (P-MS). We obtained single-voxel metabolic 1H spectra at 7 Tesla from the frontal cortex of RR-MS and P-MS patients and controls to explore the effects of disease state on concentrations of brain metabolites like glutathione, GABA, glutamate, and N-acetyl aspartate (NAA). Our results suggest an age- and disease-related decrease in glutamate, as well as a disease-related decrease in NAA, in patients with P-MS relative to RR-MS and controls without MS. No disease-related changes in GSH or GABA were found. Our data underscore the importance of continued investigation into the potential physiological distinctions among various MS subtypes. |
| 2971 | KIDNEY CANCER SUBTYPES, IDENTIFIED BY TWO DIMENSIONAL MR SPECTROSCOPY, MAY EVENTUALLY ALLOW TREAMENT OF CLINICALLY DISTINCT DISEASES. | |
1Translational Research Institute, Brisbane, Australia, 2Centre for Kidney Disease Research, UQDI, The University of Queensland, Brisbane, Australia, 3Department of Urology, Princess Alexandra Hospital, Brisbane, Australia, 4Aquesta Pathology, Brisbane, Australia |
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Small renal masses, such as non-clear cell renal carcinoma (non-ccRCC), can be monitored rather than resected as morbidity is unlikely. The distinction between malignant clear cell RCC (ccRCC) from indolent RCC subtypes and benign renal tumour is not possible by imaging thus some patients undergo unnecessary surgery1. Using 2D COrrelated SpectroscopY we report that normal renal tissue, non-ccRCC and ccRCC each has different chemical profile. ccRCC differs from normal tissue with cholesterol and lipid increased by 572% and 481% (P=0.001); decreased alanine 51% (P=0.001); valine 57% (P=0.003) and lysine 46% (P=0.005). When comparing ccRCC to the non-ccRCC there are increases in valine 48% (P=0.004) and lysine 40% (P=0.04). |
| 2972 | Longitudinal evaluation of neurochemical modulation induced by quadripulse stimulation (QPS) using ultra-short TE STEAM MRS | |
1Preparing Section for New Faculty of Medical Science, Fukushima Medical University, Fukushima, Japan, 2Advanced Clinical Research Center, Fukushima Medical University, Fukushima, Japan, 3Department of Neurology, Fukushima Medical University, Fukushima, Japan, 4Department of Radiology, The University of Tokushima Graduate School, Tokushima, Japan |
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To evaluate longitudinal neurochemical modulation induced by rTMS, we used ultra-short TE STEAM MRS. Glx, GABA and 15 other metabolites were measured using 3T MR equipment longitudinally and LCModel was used to calculate these concentrations quantitatively. QPS was employed as rTMS and left M1 was stimulated in each subject. Five healthy male volunteers participated in this study. The long-term depression intervention induced Glx increment, and the long-term potentiation intervention induced GABA decrement. The present results suggested a usefulness of the ultra-short TE STEAM MRS in evaluation of the longitudinal neurochemical modulation induced by rTMS. |
| 2973 | Effect of psychotherapeutic approaches on cortical and striatal neurochemical profile in a juvenile rat model of ADHD: an in vivo 1H MRS study @ 11.7T | |
1Core Facility Small Animal Imaging, Ulm University, Ulm, Germany, 2Institute of Anatomy and Cell Biology, Ulm University, Ulm, Germany, 3Department of Child and Adolescent Psychiatry, Ulm University, Ulm, Germany, 4Center for Magnetic Resonance Research, University of Minnesota, MN, United States |
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Proton MRS is employed to assess the effect of systemic administration of aripiprazole and riluzole on the neurochemical profile of distinct functional regions in juvenile rat brain non-invasively in vivo. In this study, a dedicated optimized STEAM sequence with single-shot phase and frequency correction, and image-based shimming was applied to quantify subtle changes in the brain metabolites concentration during drug treatment in an ADHD rat model. |
| 2974 | Influence of signal-to-noise, spectral filtering, and Cramér–Rao Lower Bounds for the optimal use of in vivo 2HG MRS to determine glioma IDH mutation status | |
1Memorial Sloan Kettering Cancer Center, New York, NY, United States, 2GE HealthCare, Berlin, Germany |
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Cancer-associated mutations in IDH results in overproduction of 2-hydroxyglutarate (2HG). A few studies have evaluated the use of MR spectroscopy (MRS) technology to noninvasively determine IDH mutation status by measuring 2HG concentrations. However, it is unknown how factors such as signal-to-noise ratio (SNR), spectral apodization, and Cramér–Rao Lower Bounds (CRLB) can influence MRS sensitivity and specificity for 2HG detection in gliomas. This study seeks to define the ideal method to define optimal thresholds of CRLB and spectral filtering resulting in improved 2HG detection sensitivity without a drop in MRS specificity. |
| 2975 | GABA concentration measurements in infants without sedation | |
1Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 2Boston Children's Hospital, Harvard Medical School, Boston, MA, United States, 3Beth Israel Deaconess Medical Center, Boston, MA, United States, 4Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, 5Boston Children's Hospital, Harvard Medical School, Boston, MA |
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We report measurements of GABA concentration in infants without sedation using the MEshcher-Garwood (MEGA) sequence. Single-voxel measurements were performed in 114 infants at approximately one month and/or three months of age. Quantification is performed with water scaling, and concentration values are reported in units of mM of NMR-visible water in the brain. For the two scan times, we found the inter-subject coefficient of variation (CV) of GABA to be 8% and 9%, respectively. Average GABA concentration values are 7% higher for the 3 month scan than the 1 month scan, indicating a gradual increase in GABA concentration after birth. |
| 2976 | Longitudinal MRS Study following Treatment of Early-Phase Psychosis with N-Acetylcysteine | |
1Health Sciences, Purdue University, Lafayette, IN, United States, 2Purdue University; Indiana University School of Medicine, 3Indiana University School of Medicine, 4Health Sciences, Purdue University; Indiana University School of Medicine, Lafayette, IN, United States |
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This study followed early stage schizophrenia patients undergoing treatment with single voxel MRS in the frontal lobe. Patients were split into a placebo (sugar pills) and treatment (N-acetylcysteine (NAC)) group and followed over the course of a year where they participated in 2-3 MRS scans at regular intervals. Patients show significantly elevated concentrations of Cre and Glx when compared to controls. This significance remained throughout the longitudinal study in intra- and inter-patient comparisons. This unchanged elevation of Glx and Cre contradicts the hypothesis that NAC will work to normalize these metabolite concentrations. |
| 2977 | Evaluation of the amygdala and the anterior cingulate cortex by single voxel proton MR spectroscopy in patients with post-traumatic stress disorder after earthquake | |
1Huaxi MR Research Center, Department of Radiology, West China Hospital of Sichuan University, chengdu, People's Republic of China |
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In order to explore the changes of metabolites in the amygdala and the anterior cingulate of PTSD after earthquake, MR spectroscopy was applied. MRS showed higher ml and NAA levels in ACC, higher NAA levels in the right amygdala of PTSD group as compared to healthy controls. Besides, both in PTSD and healthy controls, NAA+NAAG levels were higher in the left amygdala than the right. And our results indicate there are some metabolic changes in amygdala and ACC of PTSD subjects. Whether combining depressive disorders, cause of PTSD and types of traumatic causes may have contributed to the inconsistency. |
| 2978 | Attenuated excitatory metabolism in the prefrontal Cortex of single prolonged stress model: in vivo and ex vivo proton magnetic resonance spectroscopy | |
1Department of Biomedical Engineering, and Research Institute of Biomedical Engineering. The Catholic University of Korea College of Medicine, Seoul, Korea, Republic of, 2Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea, Republic of |
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The purpose of the study was to evaluate neurochemical changes in the prefrontal cortex of rats during time-dependent sensitization in the single prolonged stress (SPS) model that reveals pathogenetic neurometabolites characteristic of posttraumatic stress disorder by using in vivo and ex vivo proton magnetic spectroscopy. After the time-sensitization period, Glu and Cr levels were reduced and Cho and Lac levels were increased in SPS group in comparison with control group. These indicate that SPS induced sustained adaptation of the glutamatergic activity in PFC. |
| 2979 | Posterior cingulate gyrus metabolism differs in parkinson’s disease patients with and without cognitive impairment | |
1Department of Radiology, Affiliated Hospital of Guizhou Medical University, Guiyang, China, Guiyang, People's Republic of China |
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1H-MRS technology combined with Lcmodel software were used to quantitative the concentration of metabolites of posterior cingulate gyrus (PCC) in Parkinson’s disease patients with(PDCI) and without cognitive impairment(PDN), and MMSE and MOCA tests were also performed. Compared with controls, the concentration of total creatine (tCr), N-acetylaspartate(NAA), myo-Inositol(mI), Glutathione (GSH), as well as glycerophosphocholine + phosphocholine (tCho) were found significantly decreased in PCC in PDCI group , but no changes were found in PDN. Additionally, correlations between concentration of tCr, GSH, tCho, NAA and MMSE (MoCA) scores can also be found . These results may indicate that the metabolites abnormalities in PCC might be used as a biomarker to track cognitive decline in Parkinson's disease in a clinical setting. |
| 2980 | Brain Metabolite Changes During Motor Task: A 3T functional MRS Study | |
1Biomedical Engineering, McGill University, Montreal, QC, Canada, 2Brain Imaging Center, Douglas Mental Health Institute, Montreal, QC, Canada |
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Previous fMRS studies at 7T have shown changes in brain metabolite levels elicited by different stimuli. This 3T study employed a modified version of PRESS to effectively measure neurochemical changes generated by a finger tapping task during the MRS scan. The results show lactate in the motor cortex increased approximately 11%, while glutamate and aspartate trend toward a 2% increase and 3% decrease respectively. More subjects are required for further validation. |
| 2981 | 7 Tesla 1H MR Spectroscopy of the Motor Cortex following Transcranial Direct Current Stimulation | |
1Centre for Functional and Metabolic Mapping, Robarts Research Institute, London, ON, Canada, 2Medical Biophysics, Western University, London, ON, Canada, 3Physics and Astronomy, Western University, London, ON, Canada, 4Clinical Neurological Sciences, Division of Neurosurgery, London Health Sciences Centre, London, ON, Canada |
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Transcranial direct current stimulation (tDCS) is a form of non-invasive brain stimulation that has been used to treat numerous cognitive and motor disorders. However, its mechanism of action is poorly understood, resulting in controversy over its effectiveness. The current study used ultra-high magnetic field (7 Tesla) magnetic resonance spectroscopy to determine if metabolite ratios were altered after the application of tDCS. In this preliminary study of 8 subjects, we found no differences in metabolite ratios in the motor cortex immediately following stimulation. |
| 2982 | Brain Metabolite Level Estimation at Anterior Cingulate Cortex in Fibromyalgia Using Advanced MRS | |
1RADIOLOGY, TAIPEI VETERANS GENERAL HOSPITAL, Taipei, Taiwan, 2School of Medicine, National Yang-Ming University, Taipei, Taiwan, 3School of Biomedical Engineering and Technology, Faculty of Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan, 4NEUROLOGY, TAIPEI VETERANS GENERAL HOSPITAL, Taipei, Taiwan, 5GE Healthcare, Taipei, Taiwan, 6MR Research China, GE Healthcare, Beijing, People's Republic of China |
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We apply MEGA-PRESS MRS to measure brain metabolite level of Fibromyalgia patients and healthy controls at anterior cingulate cortex. The results show higher levels of GABA in Fibromyalgia than healthy controls but no significant difference was found in glutamine and glutamate levels. |
| 2983 | Treatments in chronic liver disease induced hepatic encephalopathy: a longitudinal in vivo 1H MRS study of brain metabolism using rifaximin | |
1Laboratory for Functional and Metabolic Imaging, Center for Biomedical Imaging, Ecole polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2Center for Biomedical Imaging(CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 3Service of Biomedicine, University Hospital of Lausanne, Lausanne, Switzerland, 4Swiss Center for Liver Disease in Children, Department of Pediatrics, University Hospitals Geneva, Geneva, Switzerland, 5Laboratory for Functional and Metabolic Imaging (LIFMET) & Center for Biomedical Imaging (CIBM), Ecole polytechnique Fédérale de Lausanne, Lausanne, Switzerland |
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Hepatic encephalopathy (HE) is a severe complication of chronic liver disease (CLD). Treatments for HE have focused on reducing plasma ammonia levels implicated in HE pathogenesis. The antibiotic rifaximin reduces the production of gut ammonia which is considered to be the main toxin in CLD-induced HE. Rifaximin is commonly used in the treatment of HE and has been shown to reduce the frequency of HE episodes, but the molecular mechanisms behind this effect are unknown. We assessed, in vivo and longitudinally, the effect of rifaximin on brain metabolites in bile duct ligated rats using high-field proton Magnetic Resonance Spectroscopy. |
| 2984 | Metabolic Subtypes of Atypical Teratoid Rhabdoid Tumors | |
1Radiology, Children's Hospital Los Angeles, Los Angeles, CA, United States |
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Atypical Teratoid Rhabdoid Tumors (AT/RT) are highly malignant pediatric brain tumors distinguished from other primitive/embryonal tumors by alterations of the SMARCB1 gene. Recently, two molecular subtypes have been described for AT/RTs. We have reviewed MR spectra of AT/RT patients and identified two distinct clusters in respect to their metabolic profiles. Should a correlation with genetic subtypes be confirmed, in vivo MRS could potentially play a key role in the initial stratification of patients diagnosed with AT/RT. |
| 2985 | Experimental setup for direct observation of hippocampal glycolysis in rat brain as a marker of cellular health | |
1RG Translational Imaging, Department NeuroImaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany, 2mfd diagnostics GmbH, Wendelsheim, Germany |
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Glycolysis is fundamental for cerebral energy metabolism. The current glycolysis pathway gives direct information about the local cellular health. To investigate hippocampal glycolysis in living rats, we established an experimental setup combining MRS and laser spectroscopy. It provides the opportunity to observe the behavior to the involved substances (glucose, lactate, NADH) for different glycolytic pathways. Under hyperglycemic conditions, blood oxygen limits glucose consumption leading to drops in NADH and lactate. In contrast, NADH and lactate concentrations increase under anaerobic conditions. This corresponds well with known literature and demonstrates the power of the presented setup to characterize hippocampal glycolysis in vivo. |
| 2986 | Demyelination of the corpus callosum in a mouse model of mucopolysaccharidosis type I | |
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, 2Departmant of Pediatrics, University of Minnesota, Minneapolis, MN, United States, 3Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, United States, 4Pediatric Bone and Marrow Transplantation, University of Minnesota, Minneapolis, MN, United States |
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Mucopolysaccharidosis type I (MPS I) is an autosomal lysosomal storage disease caused by deficiency of α-L-iduronidase enzyme, which results in glycosaminoglycans accumulation within the lysosomes. MPS I leads to progressive loss of cognitive function and substantial physical disease in children. Abnormal myelin composition and reduced expression of myelin-related genes has been recently reported in a canine model of MPS I. The purpose of this study was to demonstrate whether demyelination of the corpus callosum can be detected also in a mouse model of MPS I using in vivo 1H MRS at 9.4 T. |
| 2987 | Investigating metabolic alterations in a depressive-like rat model of chronic forced swimming stress using in vivo proton magnetic resonance spectroscopy at 7T | |
1Department of Biomedical Engineering, and Research Institute of Biomedical Engineering, The Catholic University of Korea College of Medicine, Seoul, Korea, Republic of, 2Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea, Republic of, 3Ehwa Brain Institute, Ehwa Woman's University, Seoul, Korea, Republic of |
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The chronic forced swimming stress (CFSS) depression-like animal model has been widely used to investigate the pathophysiology of depression focusing on the monoamine system. The goal of this study was to investigate the CFSS-induced metabolic effects in the prefrontal cortex (PFC) of animals showing depression-like behavior using high-field and short echo time (TE) in vivo proton magnetic resonance spectroscopy (1H MRS). The results suggest that high-field and short TE in vivo 1H MRS can reliably quantify the key metabolites involved in depression and CFSS-induced behavioral despair and metabolic alterations similar to those found in human patients with depressive disorders. |
| 2988 | Metabolic Assessment of a Migraine Model using Relaxation-Enhanced 1H Spectroscopy at Ultra-High Field | |
1Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Tallahassee, FL, United States, 2Chemical & Biomedical Engineering, Florida State University, Tallahassee, FL, United States, 3Department of Chemical Physics, Weizmann Institute of Science, Rehovot, Israel, 4Molecular Neurology Program, Huntington Medical Research Institutes, Pasadena, CA, United States |
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This study evaluates biochemical and metabolic imbalances that may result in a collection of dysfunctional pathways that are distinct in migraineurs. The high sensitivity and spectral dispersion available to 1H MRS at 21.1 T expanded metabolic profiling in an animal model of migraine to include total creatine (tCr), choline (Cho), N-acetyl-aspartate (NAA), myoinositol (mI), lactate (Lac), taurine (Tau), aspartate (Asp), Glx, a mixture of glutamate, glutamine and GABA, and Gly, the latter identified as a mixture of glycine, glutamine, and glutamate. For the migraine analogue, Lac, Gly and Tau increased while tCr decreased temporally and in comparison to saline controls. |
| 2989 | NMR phytometabolomics for evaluation of non-polar chemosensory signatures | |
1Department of NMR, All India Institute of Medical Sciences, New Delhi, India |
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With increasing interest in the role of taste related fatty acids in food, pharmacology, health and diseases, objective study of this chemosensory parameter has assumed importance. The potential of NMR metabolomics to fingerprint chemosensory properties has been explored in the context of non-polar phytocompounds in this study. Non-polar fractions obtained by dual phase (chloroform-methanol/water) extraction of select dietary plants (n=24) were studied using proton NMR spectroscopy. Partial Least Squares Discriminant Analysis of the spectral data showed distinct chemosensory based clustering. NMR based chemosensory studies of non-polar phytocompounds could open new applications in sensorial sciences related to lipids and fatty acids. |
| Exhibition Hall | Thursday 13:00 - 15:00 |
| 2990 | Integrative analysis of GABA-edited MRS data acquired at 19 research sites | |
1Russell H. Morgan Department of Radiology and Radiological Science, The 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, 3Department of Radiology, Haukeland University Hospital, Bergen, Norway, 4Department of Clinical Medicine, University of Bergen, Bergen, Norway, 5Spinoza Centre for Neuroimaging, Amsterdam, Netherlands, 6Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, United States, 7Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 8Department of Radiology, Taipei Medical University Shuang Ho Hospital, New Taipei City, Taiwan, 9Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway, 10NORMENT – Norwegian Center for Mental Disorders Research, University of Bergen, Bergen, Norway, 11Department of Kinesiology, KU Leuven, Leuven, Belgium, 12REVAL Rehabilitation Research Center, Hasselt University, Diepenbeek, Belgium, 13Brain and Consciousness Research Centre, Taipei Medical University, Taipei, Taiwan, 14School of Health Sciences, Purdue University, West Lafayette, IN, United States, 15Department of Neuroimaging, Central Institute of Mental Health, Mannheim, Germany, 16Department of Clinical Engineering, Haukeland University Hospital, Bergen, Norway, 17Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, United States, 18Department of Radiology, University of Calgary, Calgary, AB, Canada, 19Department of Neurology, BG University Hospital Bergmannsheil, Bochum, Germany, 20Department of Radiology, Taipei Veterans General Hospital, National Yang-Ming University School of Medicine, Taipei, Taiwan, 21Department of Radiology, Maastricht University Medical Center, Maastricht, Netherlands, 22GE Healthcare, Calgary, AB, Canada, 23GE Healthcare, Taipei, Taiwan, 24Department of Psychology, University of Washington, Seattle, WA, United States, 25GE Healthcare, Berlin, Germany, 26Department of Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada, 27Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States, 28Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States, 29Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada, 30Department of Psychology, University of Toronto, Toronto, ON, Canada, 31School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada, 32Leuven Research Institute for Neuroscience & Disease (LIND), KU Leuven, Leuven, Belgium, 33Department of Diagnostic and Interventional Radiology, University Düsseldorf, Düsseldorf, Germany, 34Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States, 35Institute of Clinical Neuroscience and Medical Psychology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany |
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In this large multi-vendor, multi-site study, we seek to better understand the factors that impact quantitative outcomes of GABA-edited MR spectroscopy. Data from 187 participants from 19 research sites acquired on scanners from the three major vendors were pooled and analyzed using a standard pipeline. Coefficients of variation for GABA measurements acquired on each scanner platform and across the entire cohort were less than 11%. Multilevel linear modelling showed that most of the variance was accounted for by participant-level differences, while vendor-level differences accounted for comparatively more proportional variance than site-level differences. |
| 2991 | Gannet 3.0: Developing post-processing tools for accelerated J-difference editing | |
1Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 2F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States |
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Initially conceived as |
| 2992 | Basis set optimization for quantification of semi-LASER at 9.4T under consideration of CP effect and relaxation | |
1High Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 2Graduate School of Neural and Behavioural Sciences, Tuebingen, Germany, 3Institute of Physics, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany |
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In this abstract, we evaluated the Carr-Purcell behavior of semi-LASER sequence at 9.4T and we studied the influence of different relaxation times between the different moieties of NAA and NAAG using in-vivo acquired from occipital lobe and simulated spectra. The results indicate that differences in the relaxation time between different moieties can affect the fitting results and the metabolites levels. Moreover, an estimated value for the relaxation time of NAA-aspartate moiety is given. This work indicates that more measurements and investigation should be done, studying more metabolites and brain regions. |
| 2993 | Influence of age-specific macromolecular pattern on MRS quantification | |
1Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States, 2Geriatric Research Education and Clinical Center, Minneapolis VA Medical Center, MN, United States |
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The resonances originating from high-molecular weight macromolecules (MM) underlie those of metabolites in brain 1H NMR spectra. In humans, MM content and MM pattern have been shown to depend on age of the subject. In this project, the influence of age-specific MM pattern on MR quantification was investigated. The age-associated differences in the MM pattern have a major influence on the quantification of metabolite concentrations in the aging brain which might lead to different interpretation of the data. This important finding suggests that the age-specific MM spectrum should be used in the basis set to obtain accurate concentrations of metabolites. |
| 2994 | Influence of broader spectral linewidths generated in vivo on metabolite quantification | |
1Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States |
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To understand how linewidth impacts the current best practice of quantification, the novel approach was used to measure spectra of several linewidths from each subject in contrast to the traditional approach of mathematically broadening one reference spectrum. Mathematical broadening of an in vivo spectrum reproduced the lowering of tCr concentration reported in the past. In contrast, tCr concentrations measured from broader spectra obtained using suboptimal shims tended to be higher than those measured using ideal shims. Further inquiry into the exact source of these artifacts is likely to lead to corrective approaches. |
| 2995 | Fitting comparison for 9.4T 1D semi-LASER and 2D-J-resolved semi-LASER data | |
1High-Field Magnetic Resonance, Max Plack Institute for Biological Cybernetics, Tübingen, Germany, 2Institute of Physics, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany |
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In this abstract, we present an adapted version of the ProFit-V2 fitting software to fit J-resolved semi-LASER data at 9.4T. Simulated basis sets with ideal pulses show the need to reduce the echo time to account for the spin locking effect of the adiabatic pulses. Further, a comparison of the fitting error estimations using correlation matrices and Cramer-Rao Lower Bounds with a metabolite cycled semi-LASER fitted with LCModel is done. |
| 2996 | Tissue-type dependence of in vivo chemical shifts of metabolites ? | |
1Magnetic Resonance Spectroscopy Core, NIH, NIMH, Bethesda, MD, United States, 2NIMH-IRP, 3Clinical & Translational Neuroscience Branch, NIH, NIMH |
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Recent high field susceptibility imaging experiments have revealed significant differences in water frequency in different tissue types. We studied the frequency distribution of choline, creatine, NAA, myo-inositol, glutamate, glutamine and GABA from gray matter- and white matter-dominant voxels. Based on data acquired from 135 normal subjects it was found that the best fit frequency of at least several metabolites are significantly dependent on tissue type composition. |
| 2997 | Difference optimization: Automatic correction of relative frequency and phase for 1H MEGA-PRESS spectra | |
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany |
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We present an automatic routine for alignment of GABA 1H MEGA-PRESS spectra to reduce subtraction artefacts which can compromise reliable GABA quantitation. The algorithm iteratively optimizes relative frequency and phase offsets between the edited and non-edited 1H MEGA-PRESS spectra by minimizing the sum of the magnitude of the difference spectrum. The proposed method was applied to simulated spectra with preset frequency and phase errors and in vivo MEGA-PRESS data and compared to spectral registration, an alignment method implemented in the open source FID-A toolbox1. Difference optimization demonstrated robust performance without requiring limitation of the input data range or user intervention. |
| 2998 | Pinpointing differences in diffusion characteristics of metabolites determined in human gray matter using simultaneous spectral and diffusion modeling | |
1Depts. Radiology and Clinical Research, University Bern, Bern, Switzerland, CH-3010, Switzerland |
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A recently described non-water suppressed diffusion-weighting MR spectroscopy sequence was applied in 13 healthy volunteers. The method uses the large water signal to compensate motion-related signal drop for the metabolite signals. 2D signal modeling with FiTAID allows for implementation of different prior knowledge constraints in order to prevent non-physical solutions or to restrict the number of unknown diffusion constants. In gray matter, highly significant differences for ADCs of several metabolites (faster diffusion for glutamate than NAA or myo-inositol) were found and their dependence on prior knowledge constraints investigated. |
| 2999 | Absolute Quantification of Brain Metabolites at 3T: Methods and Pitfalls | |
1Department of Neurobiology and Behavior, University of California, UCI, Irvine, CA, United States, 2Department of Neurology, University of California, UCI, Irvine, CA, United States, 3Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, United States |
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There exist several partial volume correction methods in the literature that often produce similar results. However, various tissue fractions can lead to substantial differences in estimated concentrations. These deviations are greater at longer TEs and greater cerebrospinal fluid contributions. In instances with a 75% WM fraction and no gray matter, the deviations can be up to 37% for TE of 135 ms at 3.0 T. These corrections were then applied to common regions of interest (ROI) in an MRS study involving 5 participants at 3T. By understanding where these methods deviate one can better make cross study comparisons. |
| 3000 | In vivo quantification of glutathione T2 in the human brain at 7 Tesla using echo time extension with variable refocusing selectivity and symmetry | |
1Biomedical Engineering, Columbia University School of Engineering and Applied Science, New York, NY, United States, 2Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, United States, 3Biomedical Engineering, Yale University School of Medicine, New Haven, CT, United States, 4Radiology, Columbia University School of Engineering and Applied Science, New York, NY, United States, 5Neurology, Yale University School of Medicine, New Haven, CT, United States |
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The tripeptide glutathione (L-γ-glutamyl-L-cysteinyl glycine or GSH) is an endogenous antioxidant implicated in many neurological conditions, including multiple sclerosis. Its precise quantification by proton magnetic resonance spectroscopy is, however, hampered by its uncertain T2. Here, we present a method for the quantification of GSH T2 in the human brain at 7 Tesla using optimized echo time extension delays and variable refocusing selectivity and symmetry to maximize the intensity and specificity of J-difference-edited GSH signals predicted by a full density matrix description of signal behavior. Using this method, we measured a GSH T2 of 144.2 ± 5.5 ms that is considerably shorter than that calculated for either of two common reference metabolites NAA (221.9 ± 10.3 ms) or creatine (155.3 ± 5.9 ms), emphasizing the importance of considering T2 relaxation differences in the spectroscopic measurement of these metabolites at long echo times. |
| 3001 | Diurnal effects on brain MRI volume and 1D MR neurospectroscopy | |
1Department of Medical Radiation Sciences, Newcastle University, Newcastle, Australia, 2Department of Neurology, John Hunter Hospital, Newcastle, Australia, 3Newcastle University, Newcastle, Australia, 4Hunter Medical Research Institute, Newcastle, Australia |
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Our major aim of this study was to to evaluate diurnal effects on two key MR metrics; total brain volume and neurometabolite profiles. Repeated 3D-MPRAGE and 1D-MRS were undertaken over a 10-hour period on 10 healthy subjects (aged 36.1±7.7 years). Volumetric analysis, using vendor segmentation software, did not reveal any statistically significant effect of time of day or sex on total brain volume. Spectral data processing and analysis using LCModel showed a mild increase in glycerophosphocholine and total choline levels between 7am and 12pm. Our study suggested a lack of significant diurnal effect on these parameters. |
| 3002 | The use of weighted averaging in spectroscopy studies improves statistical power | |
1Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom, 2Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, United Kingdom, 3Department of Physics, University of Oxford, Oxford, United Kingdom, 4PulseTeq Limited, Surrey, United Kingdom |
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In vivo MR spectroscopy is often characterised by a spectral signal-to-noise ratio (SNR) that varies highly between experiments, particularly when investigating non-proton nuclei. A common design for spectroscopic studies is to compare the ratio of two spectral peak amplitudes between groups, e.g. individual PCr/$$$\gamma$$$-ATP ratios in phosphorus MRS, or bicarbonate-to-pyruvate ratios in hyperpolarized $$$^{13}$$$C MRS. The uncertainty on this ratio is often neglected. We show that the correct propagation of this uncertainty improves statistical power. |
| 3003 | Bounded rate constant estimation in hyperpolarised [1-13C]pyruvate experiments by a Delayed-rejection Adaptive Metropolis Markov-Chain Monte Carlo (DAM-MCMC) Method | |
1Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom, 2Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, United Kingdom, 3Department of Physics, University of Oxford, Oxford, United Kingdom, 4Physical Sciences, Sunnybrook Research Institute, Toronto, ON, Canada |
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Hyperpolarised [1-13C]pyruvate forms an effective probe of metabolism in vivo and has been used extensively to diagnose and prognosticate cancer. Commonly, [1-13C]pyruvate metabolism is quantified by either total metabolite-to-pyruvate integral ("AUC") ratios, or by fitting metabolic models by least-squares methods. Here, we use a modified Markov Chain Monte Carlo (MCMC) method with adaptive sampling and delayed rejection to fit models to hyperpolarised datasets of the healthy rat brain generated by a spectral-spatial EPI imaging sequence . The method is able to statistically discriminates between signal and noise, and returns quantitatively bounded maps of rate constants of interest, such as $$$k_{\text{Pyruvate}\rightarrow\text{Lactate}}$$$. |
| 3004 | The effect of sex on neurochemical profile quantified from the human brain at 7T | |
1Department of Radiology, CMRR, University of Minnesota, Minneapolis, MN, United States, 2School of Public Health, University of Minnesota, Minneapolis, MN, United States |
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Sex is a critical biological factor that needs to be factored into study designs and analyses. In the present work, we sought to quantify sex-related differences of neurochemical profiles, utilizing 1H MRS data from the visual cortex of 22 healthy females (age 24±6 years) and 27 males (age 26±6 years) acquired at 7 T. Whereas there was a trend of sex-related differences for few metabolites, no statistically significant differences were observed above the attained metabolite sensitivity threshold of 0.2 µmol/g. The results indicate that sex is not a major confounding variable for MRS experiments performed on the visual cortex of young subjects. |
| 3005 | Comparison of metabolic adaptations between endurance- and sprint-trained athletes in two different muscles using a 31P spectroscopic multi-slice sequence | |
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany, 2Institute for Physiotherapy, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany |
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Due to specific training orientations athletes adapt with different metabolic responses to a given exercise. We used a 31P MR multi-slice sequence allowing a non-invasive investigation of high energy changes in two muscles. Different metabolic adaptations were shown within two muscles of different trained athletes. This may help to characterize training specific effects on energy metabolism. |
| 3006 | Linear discriminant and principle component analysis of MR spectroscopy data in pediatric mild traumatic brain injury (pmTBI) | |
1Imaging, Huntington Medical Research Institutes, Pasadena, CA, United States, 2Huntington Medical Research Institutes, Pasadena, CA, United States, 3California Institute of Technology, 4Division of Systems Biology, FDA National Center for Toxicological Research, Jefferson, AR, United States |
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Pediatric mild traumatic brain injury data is necessary to understanding and predicting recovery of cognitive and psychiatric sequelae as pediatric subjects may take longer to recover than adults. Our study presents MR spectroscopy data acquired in five different brain regions of concussed and non-concussed high school athletes. Data were analyzed utilizing linear discriminant in combination with principal component analysis. Initial results demonstrate reasonable separation of mTBI subjects compared to normal controls. In addition, data from multiple time-points after injury demonstrate a return toward normal pattern and can be used to predict recovery and return-to-play times. |
| 3007 | Temperature Calibration and Errors Assessed by Magnetic Resonance Spectroscopy | |
1Signal and Image Processing, Singapore Bioimaging Consortium, Singapore, Singapore, 2Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore, 3Singapore Institute for Clinical Sciences, Singapore, 4Miller School of Medicine, University of Miami, Miami, FL, United States |
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Whole brain temperature mapping is of great interest for investigating traumatic brain injuries. Single-voxel-spectroscopy (SVS) and CSI approaches provides limited spatial coverage in the brain, whereas 3D Echo-planar spectroscopic imaging (EPSI), covers the entire brain for investigating temperature and metabolism in traumatic brain injury and other studies . Our study focuses on calibration and validation of the temperature measurement in brain phantoms using EPSI and SVS at pre-clinical and clinical scanners, to study and analysis of whole brain temperature in rodents and humans. |
| 3008 | Effect of dietary intervention on liver fat content during the day. A pilot MR study | |
1MR Unit, Dept Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic, 2Centrum of Experimental Medicine, Institute for Clinical and Experimental Medicine, Prague, Czech Republic |
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Liver fat content is an important parameter characterizing clinical status of the liver. Steatosis can be measured by magnetic resonance spectroscopy and imaging techniques non-invasively. The group of healthy volunteers was examined by MRS and MRI on three occasions after fat load, fat load with glucose and during whole-day fasting. Obtained results show that both used MR techniques are suitable for fat content measurements in the liver during dietary intervention. The pilot study results suggest that concentration of NEFA in systemic circulation is a critical factor that determines whether fat accumulates in the liver during the day in healthy insulin sensitive subjects. |
| Exhibition Hall | Thursday 13:00 - 15:00 |
| 3009 | Investigation of the brain energy metabolism by simultaneous detection of lactate and β-hydroxybutyrate using MEGA-sLASER | |
1Department of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany |
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For the detection and quantification of lactate (Lac) and β-hydroxybutyrate (bHB) via 1H-MRS, difference editing methods such as MEGA-PRESS have been proposed. Since MEGA-PRESS suffers from substantial signal loss due to large chemical shift displacement, we propose MEGA-sLASER for simultaneous detection of the two metabolites at 3T. It is demonstrated that the signal-to-noise ratio of the target resonances in the difference spectrum is increased by a factor of two compared to MEGA-PRESS and that quantification accuracy can thus be substantially improved, enabling the robust detection of Lac and bHB in healthy brain. |
| 3010 | Improved Triple-refocusing 1H MRS at 3T for detection of GABA and Glutamate in human brain in vivo | |
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States |
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Reliable detection of GABA is important for studies in neuro-psychiatric diseases. In vivo 1H GABA resonances are extensively overlapped with the neighboring resonances including glutamate and glutamine. We present a new triple-focusing 1H MRS method which can fully resolve GABA 2.29-ppm and Glu 2.35 ppm signals at 3T. |
| 3011 | Dual spectral analysis for metabolite quantification in the presence of lipids and macromolecules | |
1Imperial College London, London, United Kingdom, 2Imperial College Healthcare NHS Trust, London, United Kingdom, 3Medical Physics & Bioengineering, University College London Hospitals NHS Trust, London, United Kingdom |
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In this study, we aim to reduce the bias inherent in fitting short echo time spectra by performing a two-point saturation recovery experiment. At both points lipid and macromolecule magnetisation is excited from an approximately fully relaxed state and so this signal component is unchanged, thus the fitting model can be constrained. We show that this may be an advantageous strategy in comparison to other common techniques, reducing bias where fitting spectra with narrow linewidths. |
| 3012 | GABA editing with reduced sensitivity to B1 inhomogeneity and improved detectability at 7T using MEGA-LASER | |
1Imaging Institute, Cleveland Clinic, Cleveland, OH, United States, 2Radiology, Massachusetts General Hospital, Charlestown, MA, United States |
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GABA spectroscopy is performed at 7T in vitro and in vivo using MEGA-PRESS and MEGA-LASER sequences. MEGA-LASER is shown to be much less sensitive to B1 inhomogeneity, and having higher signal intensity than MEGA-PRESS. Relative inter- and intra-sequence variabilities with respect to B1 inhomogeneity and regional variation are reported. Higher signal intensity in MEGA-LASER is attributed to reduced chemical shift displacement artifact and less signal loss resulting from spatial effects in phase evolution of J-coupled GABA. |
| 3013 | MASE-sLASER, a short TE matched chemical shift displacement error sequence for single voxel spectroscopy at ultrahigh field | |
1Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany, 2Translational and Molecular Imaging Institute, New York, NY, United States, 3Donders Institute for Brain, Cognition and Behaviour, Nijmegen, Netherlands |
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Conventional sLASER sequence has different Chemical Shift Displacement Error (CSDE) in one of the three slice selection directions. In this work, a short TE matched CSDE sLASER sequence (MASE-sLASER) has been implemented using the novel MASE pulses for single voxel spectroscopy at 7T. The matched low CSDE of this sequence in all three directions provides more exact representation of the metabolites in the imaged voxel. The short duration of the MASE pulses with acceptable bandwidths have made it possible to achieve a TE as short as 28 ms for the MASE-sLASER sequence despite having one more RF pulse than the conventional sLASER sequence. |
| 3014 | Editing of GABA at variable TEs with antiphase J-difference editing approach | |
1Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany, 2Donders Institute for Brain, Cognition and Behaviour, Nijmegen, Netherlands |
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The most commonly used editing MRS method for measuring GABA is MEGA which works at TE=68 ms and any odd multiples thereof. Here we present a J-difference editing method which makes it possible to measure GABA signal at variable TEs independent of the effect of J-evolution by preserving the two side peaks of GABA in antiphase states at any echo time above 34ms. We also show an application of this editing technique to be measurement of T2 relaxation time of GABA in vivo. |
| 3015 | Qualitative Comparison between In Vivo J-Resolved Semi-LASER at 3 T and 9.4 T | |
1High Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 2Department of Psychiatry, Charité - Universitätsmedizin Berlin, 3Institute of Physics, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany |
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J-resolved semi-LASER with maximum-echo sampling is optimized at 9.4T and compared with the same implementation at 3T in terms of SNR and spectral resolution. SODA scheme is appreciated for the sequence rather than the MC scheme. SNR at 9.4T (t1 steps: 85) was approximately 5.8 times greater than at 3T (t1 steps: 100) and strongly coupled peaks are well-resolved. However, the trade-off between SNR and spectral resolution is explained as lactate (1.32 ppm), a weakly-coupled metabolite, is better resolved at 3T. Higher band-width AFP pulses helped in almost vanishing the J-refocused peaks which made the J-resolved peaks clearly distinguishable. A few interesting downfield peaks and the doublet of NAA (7.82ppm) are observed. |
| 3016 | Simultaneous measurement of Aspartate, NAA, and NAAG using HERMES spectral editing at 3 Tesla | |
1Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, United States, 2Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, MD, United States, 3F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States |
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It has previously been shown that the HERMES method (‘Hadamard Encoding and Reconstruction of MEGA-Edited Spectroscopy’) can be used to simultaneously edit two metabolites (1). Examples of pairs of metabolites edited include N-acetyl-aspartate (NAA) and N-acetyl aspartyl glutamate (NAAG), or glutathione and GABA (2). Here, we demonstrate that HERMES can acquire simultaneously and then separate three overlapping edited signals, for the example of NAA, NAAG and Aspartate (Asp). We optimize this sequence using simulations, and show its feasibility in phantoms and in vivo. We also explore the echo time modulation of the aspartate spin system using simulations and phantom experiments. |
| 3017 | Very Short Echo Time MRS for Single Voxel Spectroscopy in Small Voxels | |
1Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany, 2Max Planck Institute for Biological Cybernetics, Tuebingen, Germany, 3Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany, 4Institute of Physics, Ernst-Moritz-Arndt University Greifswald, Greifswald, Germany |
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This work presents the combination of metabolite cycling with a non-water-suppressed SPECIAL localization scheme in order to enable improved averaging coherence for very short echo time MRS in small voxels or voxels that suffer otherwise from low SNR or frequency instabilities. |
| 3018 | Feasibility and Reproducibility of Neurochemical Profiling in the Human Hippocampus at 7T | |
1Department of Radiology, CMRR, University of Minnesota, Minneapolis, MN, United States, 2Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States |
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Despite advancements in single-voxel hippocampal 1H MR spectroscopy, low abundant and J-coupled metabolites, which are critically involved in neuro-energetics, memory and excitation/inhibition balance, are still poorly quantified at 3T. Hippocampal 1H MRS at 7T may benefit from higher SNR and better spectral dispersion. Thus, the precision and test-retest reproducibility of quantification achieved at 7T using semi-LASER sequence was compared to the outcome of a similarly designed 3T study. The higher SNR at 7T relative to 3T allowed using smaller voxel for more precise selection of hippocampal gray matter while demonstrating improved quantification of J-coupled and/or low abundant metabolites. |
| 3019 | Rapid Diffusion Tensor MR Spectroscopy (DTS) of Metabolites in Human Brain | |
1University of Alberta, Edmonton, AB, Canada |
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Few studies have focused on metabolite diffusion using 1H-MRS, compared to the vast number observing water diffusion by DWI/DTI. These MRS studies are lengthy, therefore difficult to implement clinically, and use up to three b-values to yield the diffusion spectra. Single exponential signal loss is assumed for metabolites, neglecting the possibility of non-linear decay at high b-values, as has been observed for water. Our goals are: (i) Characterize the metabolite signal decay versus b-value in human white matter to determine the non-linear region. (ii) Develop a rapid diffusion tensor spectroscopy method that can be executed in a clinically useful time. |
| 3020 | 4-Dimensional spin echo for prostate 1H MRSI at 7T using a multi-transmit system | |
1Imaging Division, University Medical Center, Utrecht, Netherlands, 2Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, Netherlands |
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A 4-dimensional spatially and spectrally selective spin echo sequence was developed for prostate 1H MRSI at 7T. This sequence has intrinsic water and lipid suppression properties due to the limited spectral bandwidth, so only prostate metabolites are measured. The low peak power of the pulses also leads to lower SAR deposition and RF duty cycles. Phantom experiments showed an average water suppression of 99.99% at short TE, with low SAR and RF duty cycle values compared to adiabatic pulses routinely used at higher field strengths. Combined, these properties enable fast prostate MRSI acquisitions without water and lipid artifacts. |
| 3021 | In-vivo testing of automatic voxel prescription for high inter-subject reproducibility in single-voxel MR spectroscopy | |
1Electrical Enginnering, Korea Advanced Institute of Science and Technology, Daejeon, Korea, Republic of, 2Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, MN, United States, 3Department of Radiology, Duke University Medical Center, Durham, NC, United States, 4Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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In this study, we present the implementation and outcome of a scheme for automatic voxel placement in single-voxel spectroscopy. The scheme is based on transfer of voxels prescribed on an atlas to the subject images during the scanning session and allows fast and reliable placement of voxels for spectroscopy measurements. 1H spectra of three different volumes of interest (VOIs) from multiple subjects were measured with a Siemens 3T scanner following automated and manual VOI placements. MRS data acquired using automatic placement produced spectral quality comparable to manual placement, while yielding better cross-subject spatial consistency than manual placement. |
| 3022
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Automated Voxel Placement: A Linux-based Suite of Tools for Accurate and Reliable Single Voxel Coregistration | |
1Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, United States |
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Single-voxel magnetic resonance spectroscopy (MRS) provides quantification of brain metabolite levels in vivo. However, MRS studies suffer from an often overlooked source of error variance: inconsistent voxel placement. It is well-established that metabolite levels vary by brain region and voxel tissue composition. Thus, inconsistent voxel placement increases likelihood of Type I and II errors. To address this problem, we developed and evaluated a novel and automated method of prescribing voxel placements at the time of scanning. Results demonstrated a significant improvement in prescribing accurate and reliable voxel placements between and within subjects compared to manual placement and published methods. |
| 3023 | Measuring and minimizing effects of eddy currents on selective spectral editing experiments at 3T | |
1Russell H. Morgan Department of Radiology and Radiological Science, The 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, 3CAIR Program, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada, 4Department of Radiology, University of Calgary, Calgary, AB, Canada, 5Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Calgary, AB, Canada, 6Diagnostic Imaging and Radiology, Children’s National Health System, Washington, DC, United States, 7Department of Radiology, George Washington University, Washington, DC, United States, 8Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States |
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Macromolecule-suppressed J-difference-edited MRS of GABA is extremely sensitive to B0 offsets. Relatively small frequency shifts (~10 Hz) may cause unwanted co-editing of macromolecules, to the extent that the edited ‘GABA’ signal appears negative in-vivo. We demonstrate an approach to measure transient field shifts arising from gradient-related eddy currents, and present a way to minimize these effects in order to restore correct editing. |
| 3024 | MEGA-PRIAM: Dual-volume excitation and parallel reconstruction for J-difference-edited MR spectroscopy | |
1Russell H. Morgan Department of Radiology and Radiological Science, The 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, 3Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, United States, 4Hvidovre Hospital, Danish Research Center for Magnetic Resonance, Hvidovre, Denmark |
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A twofold acceleration of MEGA-edited spectroscopy, using Parallel Reconstruction In Accelerated Multivoxel (MEGA-PRIAM) to simultaneously acquire data in two separate locations, is demonstrated. PRIAM separates the signals from two dualband-excited voxels using spatial receiver-coil sensitivity profiles. Phantom experiments show that MEGA-PRIAM separates GABA- and glutathione-edited spectra with low crosstalk between the voxels. In-vivo experiments establish that dual-voxel MEGA-PRIAM increases signal-to-noise ratio (SNR) 40% compared to sequentially acquired single-voxel MEGA-PRESS measurements with the same total duration. GABA and glutathione estimates are consistent between dual-voxel MEGA-PRIAM and single-voxel MEGA-PRESS acquisitions. |
| Exhibition Hall | Thursday 13:00 - 15:00 |
| 3025 | Quantifying pO2-Driven Longitudinal Relaxation of Water 1H Spins in the Presence of Magnetization Transfer: Cross-Linked BSA as a Tissue Mimic | |
1Physics, Washington University, Saint Louis, MO, United States, 2Chemistry, Washington University, Saint Louis, MO, United States, 3Radiology, Washington University, Saint Louis, MO, United States, 4Siteman Cancer Center, Washington University, St Louis, MO, United States |
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Crosslinked bovine serum albumin phantoms are used as tissue biexponential relaxation surrogates/mimics to investigate the potential of R1-based tissue-O2 quantification and to characterize the influence of physiologically relevant variations of temperature and protein concentration on such determinations. The relaxation-rate constant for the rapidly relaxing apparent water population is dominated by magnetization transfer and is insensitive pO2. The relaxation-rate constant for the slowly relaxing apparent water population is linearly related to pO2 and provides the basis for a possible MR-Oximetry protocol. |
| 3026 | Brain redox imaging using blood-brain-barrier nitroxides by digital EPR imaging system | |
1Sapporo Medical University, Sapporo, Japan, 2Osaka University, Osaka, Japan |
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Electron paramagnetic resonance (EPR) imaging is a noninvasive imaging method for visualizing the brain redox status using nitroxide compounds as imaging probes. A digital imaging system for three-dimensional continuous-wave EPR imaging of small animals was developed using a high-speed analog-to-digital converter, digital-to-analog converters and field programmable gate array integrated circuits to improve the signal-to-noise ratio (SNR) and visualize the precise brain redox status in mice. Compared to an analog EPR imager, the digital EPR imager obtains a higher SNR of a phantom and produces images with sufficient quality to create a more accurate brain redox map of the mouse head. |
| 3027 | Towards Imaging the Glycolytic and Glutaminolytic Differences in Prostate Cancer Cell Lines that Affects Outcome of Glutaminase Inhibition | |
1Cancer Systems Imaging, MD Anderson Cancer Center, Houston, TX, United States, 2Bioengineering, Rice University, Houston, TX, United States, 3Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology, Rockville, MD, United States, 4Applied Chemistry, Hanyang University, Korea, Republic of, 5University of Houston Downtown Campus, Houston, TX, 6Huntington Medical Research Institutes, Pasadena, CA, 7MD Anderson Cancer Center, Houston, TX, United States |
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To understand and image how metabolism changes in prostate cancer (PCa), we determined both extracellular and intracellular metabolic profile of four PCa cell lines with varying degrees of aggressiveness. Differences in metabolism and mechanistic link were further explored using carbon-13 glucose and glutamine feeding studies and hyperpolarized pyruvate metabolic imaging trials with subcutaneous xenograft PC3 and PC3M animal models. We found increased glutamine utilization in the more metastatic cell line PC3M and this increased dependence on glutamine leads to reduction in cell proliferation and ATP when cells are treated with glutaminase inhibitor CB-839. No reduction is seen in PC3 line. |
| 3028 | PROTON NMR METABOLIC PROFILING OF CSF REVEALS DISTINCT DIFFERENTIATION OF MENINGITIS WITH NEGATIVE CONTROLS | |
1Departent of Microbiology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, India, 2Centre of Biomedical Research, Lucknow, India, 3Department of Neurology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, India, 4Department of Microbiology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow |
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The chemical composition of cerebrospinal fluid (CSF) in central nervous system (CNS), varies during onset of meningitis, neurodegenerative disorders and in traumatic cases.The study attempted to observe the metabolic variation in meningitis cases, negative controls and positive controls. Further differentiation among the groups was carried out using Principal Component Analysis (PCA) followed by Partial Least Square Discriminant Analysis (PLS-DA).On the basis of metabolic profile it was found that negative control CSF samples are more appropriate for differentiation of meningitis than positive control CSF samples.The biomarkers identified were ketone bodies, amino acids, propylene glycol, citrate and creatine/creatinine. |
| 3029 | Longitudinal Investigation of the Metabolome of Developing 3D Aggregating Brain Cell Cultures at Different Maturation Stages by 1H HR-MAS NMR | |
1Depts. Radiology and Clinical Research, University Bern, Bern, Switzerland, 2Dept. Chemistry and Biochemistry, University Bern, Bern, Switzerland, 3Dept. Physiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland, 4Swiss Center for Applied Human Toxicology (SCAHT), Switzerland |
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3D rat brain aggregate model is an excellent tool for mechanistic studies including OMICS analysis. However, their metabolic profile have not been yet fully investigated. The aim was to investigate by 1H-HR-MAS NMR the metabolic fingerprint of 3D brain cell cultures at different maturation stages to establish a developmental profile of metabolic changes. Chemometric analysis revealed a clear separation of samples from the different maturation days. Metabolite concentration evolutions could be followed and revealed strong and various metabolic alterations. The strong metabolite evolution emphasizes the brain modelling complexity during maturation, possibly reflecting physiological processes of brain tissue development. |
| Exhibition Hall | Thursday 13:00 - 15:00 |
| 3030 | Hyperpolarized [6-13C,6-15N3]-Arginine as a Novel Probe to Interrogate Arginase Activity | |
1Memorial Sloan Kettering Cancer Center, New York City, NY, United States |
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Across most cancer types, increased macrophage infiltration is associated with a worsening prognosis. This is because tumor associated macrophages (TAMs) exhibit a variety of pro-tumor effects ranging from vascular recruitment, cell proliferation, extravasation, and immune suppression. A marker of TAMs is arginase-1 expression, which converts arginine to urea and ornithine. It is thought that arginase expression reduces the amount of arginine available to local T-cells, leading to T-cell receptor dysfunction. In this abstract, we outline the synthesis and characterization of novel compound [6-13C,6-15N3]-Arginine as a hyperpolarized 13C MRS probe to interrogate arginase activity, with the potential for in vivo translation. |
| 3031 | Hyperpolarization of [4-13C]5-aminolevulinic acid | |
1Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States, 2Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, United States, 3Center for Biomedical Engineering and Technology (BioMET), University of Maryland School of Medicine, Baltimore, MD, United States, 4Physiology, University of Maryland School of Medicine, Baltimore, MD, United States |
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We performed the first DNP hyperpolarization of 13C-labeled 5-aminolevulinic acid (5-ALA), achieving 13% polarization at dissolution and measuring a T1 of 20 s. 5-ALA is used for fluorescent imaging and photodynamic therapy of glioblastoma, and our results suggest it is also a promising substrate for hyperpolarized metabolic imaging of this cancer. |
| 3032 | Hyperpolarization of 2-keto[1-13C]isocaproate for in vivo studies with photo-induced radicals | |
1Laboratory for Functional and Metabolic Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 2Institute of Physics of Biological Systems, Swiss Federal Institute of Technology, Lausanne, Switzerland, 3General Electric Healthcare, Chalfont Saint Giles, United Kingdom, 4Department of Radiology, University of Lausanne, Lausanne, Switzerland, 5Department of Radiology, University of Geneva, Geneva, 6Centre for Biomedical Imaging, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland |
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Hyperpolarized 2-keto[1-13C]isocaproate (KIC) provides a means to probe brain nitrogen homeostasis and to assess molecular signatures of tumors. The dynamic nuclear polarization process requires a free-radical polarizing agent, and samples are typically doped with persistent radicals. An alternative is to use photo-induced radicals of α-keto acids that recombine upon dissolution. [1-13C]KIC hyperpolarized with photo-induced radicals could be used to measure the alterations in amino acid metabolism that are linked to neurodegenerative diseases and cancer, and the aim of the present study is to identify the main features that influence the polarization dynamics. |
| 3033 | SQUID-based ultralow field nuclear magnetic resonance spectroscopy using the para-H2 based hyperpolarization technique SABRE | |
1High-field Magnetic Resonance, MPI for Biological Cybernetics, Tuebingen, Germany, 2Physikalisches Institut and Center for Quantum Science (CQ) in LISA+, University of Tübingen, Germany, 3Institue of Inorganic Chemistry, University of Tübingen, Germany, 4Department for Biometrics and Medical Informatics, Otto-von-Guericke-University Magdeburg, Germany |
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SABRE is a technique to achieve continuous hyperpolarization for MR measurements by the interaction of para-hydrogen and a substrate via steady ligand exchange on a catalyst. Thus, MR-active nuclei can be hyperpolarized more than only once. At field strengths of mT Faraday coils, commonly used in conventional or high field MRI, become insensitive and SQUIDs performing superior. Since SQUIDs are broadband detectors, the static magnetic field B0 can be changed easily or multiple nuclei can be measured simultaneously. Here, we successfully demonstrate the advantages of a SQUID based system by showing significant signal enhancement (1H, 19F) by hyperpolarization of 3-fluoropyridine. |
| 3034 | Nanodiamond Imaging with Hyperpolarized 13C MRI | |
1ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, University of Sydney, Sydney, Australia, 2School of Physics, University of New South Wales, Sydney, Australia |
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Hyperpolarized 13C MRI leverages an over 10 000 times increase in the 13C polarization of biomolecules, enabling new molecular imaging applications. However, metabolic applications are limited to processes on the timescale of a minute by the short lifetime of the hyperpolarized signal. Here, we hyperpolarize nanodiamonds and microdiamonds to achieve large, long-lived 13C polarizations. We then image these particles in phantoms, demonstrating the potential of hyperpolarized nanodiamonds for imaging over long timescales. As nanodiamond has been established as a biocompatible platform for drug delivery, our results will motivate further research into hyperpolarized MRI for tracking nanoparticles in vivo. |
| 3035 | Transport of Hyperpolarized Nanodiamonds | |
1ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, University of Sydney, Sydney, Australia |
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Hyperpolarized 13C MRI using nanodiamond (ND) holds the potential for tailored diagnostic imaging combined with targeted drug delivery in the human body. An obstacle to realizing this potential is the transfer of hyperpolarized ND from the hyperpolarizer to the patient without losing the majority of the 13C polarization as it travels through low magnetic fields before reaching the MRI scanner. We demonstrate that polarization loss is highly dependent on magnetic field and construct a system of transfer magnets that improves the transfer efficiency of our hyperpolarized ND by more than an order of magnitude. |
| 3036 | photo-CIDNP for 19F MR amino acid-protein interaction studies in physiological solvents | |
1Department for Biometrics and Medical Informatics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany, 2Institute of Physical and Theoretical Chemistry, University of Bonn, Bonn, Germany |
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Fluorinated amino acids are of high interest in biochemistry and pharmaceutics. The low 19F MR signal was increased employing hyperpolarization (photo-Chemical Induced Dynamic Nuclear Polarization, photo-CIDNP). 3-Fluoro-tyrosine in physiologic salt solution was hyperpolarized in presence of an albumin derivative using a low cost LED allowing repetitive irradiation and increasing the hyperpolarized signal. A clear 19F signal enhancement could be observed. In comparison to past examinations with a laser system, only small temperature changes caused by LED light irradiation were measured in the current study. |
| 3037 | Simultaneous Visualization of Hyperpolarized Fluorinated Amino Acids by Multi Chemical Shift Selective 19F MRI | |
1Experimental Cardiovascular Imaging, Heinrich Heine University, Düsseldorf, Germany, 2Molecular Cardiology, Heinrich Heine University, Düsseldorf, Germany |
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We demonstrate the induction of 19F photo-chemically induced dynamic nuclear polarization (photo-CIDNP) in 19F MR imaging experiments. To this end, we made use of laser-induced hyperpolarization in a system consisting of flavin mononucleotide as a photosensitizer and the fluorinated aromatic amino acids tyrosine and tryptophan, respectively. The induction of 19F photo-CIDNP led to an extensive 19F signal enhancement which could be exploited for simultaneous imaging of both amino acids by 19F multi chemical shift-selective imaging within 20 s. Hence, our approach resulted in a substantial improvement of the intrinsically low 19F MR sensitivity for mono-fluorinated amino acids. |
| 3038 | Examination of the hyperpolarizability of fluorinated nicotinic acids and further pyridine carboxylic acids using SABRE | |
1Department for Biometrics and Medical Informatics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany, 2Eduard-Zintl-Institute for Inorganic and Physical Chemistry, Technical University Darmstadt, Darmstadt, Germany, 3Institute of Physical and Theoretical Chemistry, University of Bonn, Bonn, Germany |
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Nicotinic acid and isonicotinic acid are two derivatives of pyridine carboxylic acids. Both substrates are of high interest in medical chemistry. In the current study seven fluorinated derivatives of these pyridine carboxylic acids were chosen for examination of the 1H and 19F hyperpolarizability using the SABRE technique. Influences of the position of the carboxylic group and fluorine as well as the catalyst system concerning the achievable signal enhancements were examined. Furthermore an H/D-exchange could be observed in some cases. The presented data gives important information for future MR imaging studies. |
| 3039 | Resolving spin-spin couplings in hyperpolarized in vivo metabolic 13C spectroscopy at low magnetic field following murine tail-vein injection | |
1Radiology, Vanderbilt University Institute of Imaging Science, Nashville, TN, United States |
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We demonstrate murine whole-body MRS and the ability to resolve the 13C multiplet of hyperpolarized 1-13C-succinate-d2 in a biplanar magnet with B0 = 0.0487 T and inhomogeneity <13 ppm over 40 cm DSV. At low magnetic field strength no loss of SNR relative to high field for a well-designed radiofrequency coil occurs, but chemical shift dispersion is potentially insufficient to differentiate hyperpolarized metabolites and contrast agents. However, at sufficiently low field strength, magnetic susceptibility derived B0 field inhomogeneity in vivo becomes negligible. Consequently, direct spectroscopic resolution of spin-spin couplings or J-couplings, more commonly performed near zero field, becomes feasible. |
| 3040 | Spatio-temporally constrained reconstruction for hyperpolarized carbon-13 MRI using kinetic models | |
1Electrical Engineering & Computer Sciences, University of California, Berkeley, Berkeley, CA, United States, 2Radiology & Biomedical Imaging, UCSF, San Francisco, CA, United States, 3Medicine, UCSF, San Francisco, CA, United States, 4Clinical Pharmacy, UCSF, San Francisco, CA, United States |
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We present a method of generating metabolism maps from dynamic hyperpolarized carbon-13 MRI images. By incorporating prior information into our model-based reconstruction via spatial regularization of the parameter maps, we achieve two qualitative benefits: elimination of non-identifiability in unperfused background regions, and denoising. This method is illustrated on a simulated dataset and a clinical prostate cancer dataset. |
| 3041 | Improved reconstruction for IDEAL spiral CSI | |
1Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark, 2MR Research Centre, Aarhus University, Aarhus, Denmark, 3GE Global Research, Munich, Germany |
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In this study we demonstrate how reconstruction for IDEAL spiral CSI (spectroscopic imaging scheme developed for hyperpolarized dynamic metabolic MR imaging) can be improved by using regularization with a sparsity constraint. By exploiting sparsity of the spectral domain, IDEAL spiral CSI can achieve chemical shift encoding by acquisition of only few time-shifted echoes. The minimum number of echoes required to avoid noise amplification can be decreased by means of regularization enforcing spectral sparsity, hereby reducing scan time. Improvements achieved by using regularized reconstruction are demonstrated for in vivo data from a hyperpolarized cardiac study of a pig. |
| 3042 | Characterization and flip angle calibration of 13C surface coils for hyperpolarization studies | |
1Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark, 2Department of Clinical Physiology, Nuclear 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, Frederiksberg C, Denmark |
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The aim of the present work is to address the challenge of optimal flip angle calibration of 13C surface coils in hyperpolarization studies. To this end, we characterize the spatial profile of the flip angle and demonstrate that it allows for a simple calibration improving the signal-to-noise ratio for hyperpolarized 13C magnetic resonance spectroscopic imaging. |
| 3043 | A Preliminary Framework for Validation of HP MRI using Mass Spectrometry | |
1Department of Imaging Physics, UT MD Anderson Cancer Center, Houston, TX, United States, 2Department of Head & Neck Surgery, UT MD Anderson Cancer Center, Houston, TX, United States, 3Department of Bioinformatics & Computational Biology, UT MD Anderson Cancer Center, Houston, TX, United States |
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Dynamic imaging of HP pyruvate shows tremendous promise for offering new insight into tumor metabolism with unprecedented sensitivity, specificity, and spatiotemporal resolution. Imaging constraints due to the finite, nonstationary, and non-renewable signal pool necessitate the use of complex imaging and reconstruction strategies, but current approaches to validation of complex HP MRI measurements are lacking and new methods are critically needed. In this work, we investigate a framework for external validation of quantitative HP MRI biomarkers of tumor metabolism using stable isotope tracer analysis (MS-SITA). We show good agreement between quantitative biomarkers of chemical conversion derived from HP MRI and MS-SITA. |
| 3044 | Simulation of Hyperpolarized Perfusion MRI with a Segmented Snapshot Acquisition | |
1Department of Imaging Physics, UT MD Anderson Cancer Center, Houston, TX, United States, 2Department of Head & Neck Surgery, UT MD Anderson Cancer Center, Houston, TX, United States |
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Metabolically inert hyperpolarized tracers can be used for perfusion measurements in vivo. In this work we present a simulation study to compare the performance for measurement of tissue perfusion of a conventional imaging approach to a segmented snapshot acquisition where each segment ends with a 90 degree RF pulse. |
| 3045 | Practical Considerations of Quantitative kPL Estimation in Hyperpolarized-13C Imaging in Response to Pulse Sequence Design and Parameters | |
1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, 2UCSF/UC Berkeley Graduate Program in Bioengineering, University of California, San Francisco, San Francisco, CA, United States, 3GE healthcare, Menlo Park, CA, United States |
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Hyperpolarized-13C MRI has recently enabled imaging of cancer pathophysiology with high spatiotemporal resolution in humans. Quantitative measure of tumor metabolism can be made possible by estimating conversion rate constants (e.g. kPL for pyruvate-to-lactate). We have identified 3 systematic sources affecting kPL estimation that were introduced by MR acquisition and pulse sequences – an RF-spoiling effect, a T2*-weighting factor, and a crusher flow-suppression phenomenon. These sources were investigated using a transgenic cancer model and simulations. |
| 3046 | A fuzzy Markov random field approach for the unsupervised segmentation of hyperpolarized 13C MRI data | |
1Department of Radiology, University of Cambridge, Cambridge, United Kingdom, 2Integrated Mathematical Oncology, Moffitt Cancer Centre, Tampa, FL, United States, 3Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, United Kingdom |
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MRI with hyperpolarized 13C-labelled compounds is an emerging clinical technique allowing in vivo metabolic processes to be characterized non-invasively. Accurate quantification of metabolism requires a region-of-interest to be defined, which is usually based on spatial information only. However, as the hyperpolarized data is 5-dimensional (spatial, temporal and spectral), it offers the possibility of applying novel segmentation methods to more accurately define this region-of-interest. A novel solution to the problem of 13C image segmentation is proposed here, using a hybrid Markov random field model with fuzzy logic. Performance of the algorithm is demonstrated using in silico and in vivo data. |
| Exhibition Hall | Thursday 13:00 - 15:00 |
| 3047
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Whole-Brain Visualization of Manganese Deposition in Welders | |
1Purdue University, West lafayette, IN, United States, 2Indiana University School of Medicine, Indianapolis, IN, United States, 3Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States, 4Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA, United States |
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While the paramagnetic properties of Mangnaese (Mn) make it useful as a contrast agent for MRI, little is known about the spatial distribution of Mn deposition in the human brain due to occupational Mn exposure. Using a novel approach to analyze and visualize whole brain Mn deposition in welders, Mn was elevated in motor and cognitive associated networks, consistent with respective reports on impaired neuropsychological function. Our Mn maps even reveal the diffusion of Mn along white matter tracts for the first time in humans. These findings help explain how Mn exposure affects the function of particular brain networks. |
| 3048 | High Resolution MEMRI Reveals the Purkinje Cell Layer as the Source of Contrast in the Mouse Cerebellum | |
1Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY, United States, 2Biomedical Imaging Graduate Program and Department of Radiology, New York University School of Medicine, New York, NY, United States, 3Mouse Imaging Centre, The Hospital for Sick Children, Toronto, ON, Canada |
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Imaging the developing mouse brain with conventional MRI is challenging. Manganese-enhanced MRI (MEMRI) has the potential to provide a noninvasive, in vivo approach for analyzing mutant phenotypes in the early postnatal mouse cerebellum. We present preliminary data generated using a CryoProbe (Bruker) suggesting that the primary source of Mn contrast in the mouse cerebellum is the Purkinje cell layer. |
| 3049 | Gd complex of DO3A-benzothiazole conjugate for neutron capture therapy | |
1Division of RI-Convergence Research, Korea Institute of Radiological & Medical Sciences, Seoul, Korea, Republic of, 2Department of Medical & Biological Engineering, Kyungpook National University, Daegu, Korea, Republic of, 3Department of Radiology and Molecular Medicine, Kyungpook National University, Daegu, Korea, Republic of, 4Institute of Biomedical Engineering Research, Kyungpook National University, Daegu, Korea, Republic of |
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We have presented a strategy for incorporating low-molecular-weight Gd(III) chelate for dual non-invasive MR contrast agent and NCT, without the necessity of loading individual contrast therapeutic drugs, which is usually required in theranostics. The Gd-DO3A-BTA injected and neutron irradiated group, the tumor growth was significantly suppressed. This information could provide a basis for the prospect of obtaining a synergistic or cumulative action of chemotherapy (ChT) and Gd-NCT. We examined the neutron capture irradiation of MDA-MB-231 mice in the presence of Gd-DO3A-BTA. The results indicate that Gd-DO3A-BTA is suitable neutron capture agent for Gd-NCT. |
| 3050 | Mn-complex of DO2A-benzothiazole chelate as a new hepatobiliary MRI contrast agent | |
1Medical & Biological Engineering, Kyungpook National University, Daegu, Korea, Republic of, 2Department of Molecular Medicine & BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University, Daegu, Korea, Republic of, 3Institute of Biomedical Engineering Research, Kyungpook National University, Daegu, Korea, Republic of, 4Department of Radiology, Kyungpook National University |
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The purpose of the present work is to design and synthesize a new bifunctional complex for use in Mn(II)-based liver-targeting MR imaging. Its r1 relaxivity in human serum albumin (HSA) solution is 3.21 mM-1s-1, similar to MRI CA such as MnDPDP®. In vivo MR image after injection of Mn-DO2A-BTA by tail vein showed that its excretion is made via kidney and also bile duct, confirming hepatobiliary uptake. |
| 3051 | Cyclodextrin-based pseudo-rotaxanes as conjugatable molecular imaging biosensors for hyperpolarized 129Xe MRI | |
1Lakehead University, Thunder Bay, ON, Canada, 2University of Guelph, 3University of Rhode Island, 4Lakehead University, MURILLO, ON, Canada |
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Hyperpolarized (HP) 129Xe molecular imaging technology has recently advanced in the detection of biochemically inactive supramolecular cage-molecules within a living mammalian model. Unfortunately, the natural bio-distribution of these biosensor molecules is non-specific, which makes it difficult to precisely localize them in vivo using HP 129Xe MRI. With the HyperCEST detection of easily conjugated cyclodextrin-based pseudo-rotaxanes, we have identified a critical advancement in 129Xe biosensor design by uncovering a novel biosensor, which has the potential to precisely detect markers of early disease in a human body with comparable sensitivity to PET but with the spatial resolution of MRI. |
| 3052 | Mn2+ uptake mechanisms in organotypic rat hippocampal slice cultures | |
1National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States |
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MEMRI can be used for different applications such as tracing neuronal connections or functional imaging. However, Mn2+ uptake and transport mechanisms are still unclear. These mechanisms were studied in an organotypic hippocampal slice culture. After adding Mn to the medium, MRI contrast changes were affected by Ca channel manipulation and other metals that use divalent metal transporters. Mn cellular uptake was also affected by both, the presence of glutamate receptor antagonist and a neuronal activity inhibitor. Our results establish hippocampal slice as a system to study the cellular mechanisms related to MEMRI. |
| 3053 | A Janus Chelator Enables Biochemically Responsive MRI Contrast With Exceptional Dynamic Range | |
1A. A. Martinos Center for Biomedical Imaging, MGH/ Harvard Medical School, Charlestown, MA, United States |
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Mn-JED is a new biochemically responsive MRI contrast agent that provides 9-fold relaxivity change by switching between the Mn(3+) and Mn(2+) oxidation states. The JED chelator is the only chelator that supports both the Mn(3+) and Mn(2+) oxidation states in biological milieu. Rapid interconversion between oxidation states is achieved by peroxidase activity (oxidation) and cysteine (reduction). Peroxidase activity is drastically elevated during acute inflammation. Thiols such as cysteine are overabundant in the microenvironment of proliferative tumors. Mn-JED provides a new paradigm for the design of biochemically responsive MRI contrast agents. |
| 3054 | Diamagnetic imaging agents with a modular chemical design for quantitative detection of β-galactosidase and β-glucuronidase activities with catalyCEST MRI | |
1Pharmaceutical Sciences, University of Arizona, Tucson, AZ, United States, 2Chemistry and Biochemistry, University of Arizona, Tucson, AZ, United States, 3Pharmacy, University of Arizona, Tucson, AZ, United States, 4Biomedical Engineering, University of Arizona, Tucson, AZ, United States |
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We have designed and synthesized new MRI agents that quantitatively detect β-galactosidase and β-glucuronidase activities by measuring changes in chemical exchange saturation transfer (CEST). Based on a modular approach, we incorporated the enzymes’ respective substrates to a salicylate moiety with a spontaneously disassembling, chromogenic spacer via a carbamate linkage. This design furnished highly selective diamagnetic CEST agents that detected and quantified enzyme activities of glycoside hydrolase enzymes. Michaelis-Menten enzyme kinetics studies were performed by monitoring catalyCEST MRI signals, which were validated with UV-vis assays. |
| 3055 | Tumor-targeted alkylphosphocholine chelates for dual-modality PET/MR imaging | |
1Department of Radiology, University of Wisconsin Madison, Madison, WI, United States, 2Department of Neurological Surgery, University of Wisconsin Madison, Madison, WI, United States, 3Department of Medicine - Endocrinology, University of Wisconsin Madison, Madison, WI, United States |
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Extensive structure-activity relationships studies have previously shown that alkylphosphocholine (APC) analogs selectively deliver radioiodine and larger fluorophores to a variety of tumor types in rodent models and humans1-3. To further explore the payload capacity of APCs, we synthesized several new APC-chelates and assessed their ability to deliver Gd (MRI) and 64Cu (PET) selectively to tumors in vivo. Prolonged T1-weighted signal enhancement following Gd-DOTA-APC injection was observed in all tumor models. Clinical PET/MR imaging of U87 flank xenograft at 24h and 48h post-administration of Gd-DOTA-APC and 64Cu-DOTA-APC demonstrated co-localization of T1-weighted signal enhancement and PET activity in the tumor. |
| 3056 | Facile and Novel Synthesis of MR/NIR Dual Modal Contrast Agent for In Vivo Non-invasive Molecular Imaging | |
1Bioimaging Research Team, Korea Basic Science Institute, Cheongju-si, Korea, Republic of |
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We proposed the phase transferring method of hydrophobic magnetic nanoparticles without any chemical modifications, for use as a magnetic resonance (MR)/near-infrared (NIR) fluorescence bimodal imaging contrast agent. Indocyanine green (ICG) was used both as an optical component and a surfactant for phase transfer with no superfluous moiety. ICG-MNP-labeled dendritic cells presented MR/NIR dual-modal imaging properties with high and sensitive detection ability for a long time. We expect that this novel MR/NIR contrast agent with sensitive detection and simultaneous imaging capability can be used in the imaging and tracking of immune cells to confirm immunotherapeutic efficacy. |
| 3057 | Multifunctional magnetic nanocomposites for T1/T2 Dual-Mode MRI and pH-responsive drug delivery | |
1Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, People's Republic of China |
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In this abstract, multifunctional Fe3O4@SiO2@PAA-cRGD nanocomposites were designed and synthesized to load water soluble Mn-porphyrin and anticancer drug doxorubicin, which could realize both pH-responsive drug release and T1/T2 dual-mode MRI capability. In vitro cell fluorescent imagings showed that c(RGDyk)-modified nanocomposites can effectively target A549 cells. Furthermore, in vitro T1-weighted and T2-weighted MR images of A549 cells were observed. For in vivo MRI, T1 and T2 relaxation was significantly accelerated in the tumor after i.v. injection of nanocomposites. These evidences showed that the nanocomposites could be used as pH-responsive T1/T2 dual-mode contrast agent, and have the potential for the tumor-targeted MRI and drug delivery. |
| 3058 | Extrinsic MRI contrast agents based on nuclear quadrupole enhanced relaxation: Principle, requirements and characterization of promising compounds | |
1Institute of Medical Engineering, Graz University of Technology, Graz, Austria, 2Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Poland, 3Department of Chemistry, Umeå universitet, Sweden, 4Institute of Inorganic Chemistry, Graz University of Technology, Graz, Austria, 5Institute for Chemistry and Technology of Materials, Graz University of Technology, Graz, Austria |
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Quadrupole Relaxation Enhancement is a quantum mechanical effect that can be exploited to create a new generation of extrinsic contrast agents for usage in MRI. In this work we have investigated the physical requirements of such contrast agents have to meet to be useful. Based on our findings concerning nuclear quadrupole resonance-properties, spin relaxation behavior and toxicity we suggest a variety of 209Bi-aryl compounds. The sensitivity of these compounds onto chemical or magnetic field changes equip them with smart properties such as on/off switching of the contrast or molecular imaging. |
| 3059 | Synthesis of Amplifiable Probe Gd-5-HT-DOTAGA and Application to Molecular Imaging of Pulmonary Inflammation | |
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2University of Massachusetts Medical School, Worcester, MA, United States, 3Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, United States |
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We report the synthesis of a new amplifiable MR probe that combines the stability of the macrocyclic Gd-DOTA core with the myeloperoxidase-reactive 5-hydroxytryptamide (5-HT) moiety. The relaxivity of Gd-5-HT-DOTAGA is increased 60% in the presence of myeloperoxidase activity. In a mouse model of bleomycin induced lung injury, the change in lung-to-muscle contrast to noise ratio is increased 50% compared to naïve animals, consistent with 3-fold higher Gd lung concentrations measured ex vivo. |
| 3060 | Synthesis of hepatocyte-specific manganese complex with high kinetic stability and MR contrast characteristic for liver cancer imaging | |
1BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University, Daegu, Korea, Republic of, 2Medical & Biological Engineering, Kyungpook National University, Daegu, Korea, Republic of, 3Institute of Biomedical Engineering Research, Kyungpook National University, 4Radiology, Kyungpook National University |
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Novel manganese (II) complex based on EDTA coordination cage bearing benzothiazole aniline (BTA) moiety with high chelation stability was designed and synthesized for use as a liver-specific MRI contrast agent. In addition to forming a hydrophilic, this new hepatobiliary Mn(II) chelate is rapidly taken up by hepatocyte of liver. The magnetic and kinetic properties of Mn(II) complex are higher than commercially available analogue, Mn-DPDP, which was clinically approved MR liver contrast agent. The complex, Mn-EDTA-BTA, was evaluated via in vivo MR imaging to prove high tumor detection sensitivity using animal liver tumor model. |
| 3061 | Detection of sulfatase enzyme activity with a catalyCEST MRI contrast agent | |
1Chemistry and Biochemistry, University of Arizona, Tucson, AZ, United States, 2Pharmaceutical Sciences, University of Arizona, Tucson, AZ, United States, 3Medical Imaging, University of Arizona, Tucson, AZ, United States |
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CatalyCEST MRI with a diamagnetic CEST agent, 4-acedamido-2-(sulfoxy)benzoic acid, can detect the activity of sulfatase. An enzyme-responsive CEST signal was compared to an unresponsive CEST signal to determine a reaction coordinate of contrast agent cleavage by sulfatase. This imaging method produced parametric maps of CEST signal amplitudes and the reaction coordinates. Three isoforms of the enzyme were tested in biochemical solutions. catalyCEST MRI with the agent detected sulfatase activity in the media from sulfatase-expressing HEK293 cells but not in the media of sulfatase-deficient BT529 cells. |
| 3062 | One-pot microwave synthesis of fluorinated silicon nanoparticles for dual 19F-MRI and fluorescence imaging | |
1Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, People's Republic of China |
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In this study, we have designed a one-pot microwave strategy for facile and rapid synthesis of blue-emitting 19F-SiNPs. The as prepared 19F-SiNPs significantly exhibited ultral small sizes, excellent water solubility and strong fluorescence. Besides, The chemically and magnetically equivalent trifluoromethyl groups grafted on the prepared nanoparticles displayed a single NMR signal, which offered advantages to maximize the generated magnetic resonance signal. In summary, such resultant 19F-SiNPs are particularly suitable for real-time 19F-MRI and fluorescence dual modality imaging. |
| 3063 | Simultaneous imaging of drug delivery with SPIO-based MRI and drug therapy with pHe readout from BIRDS | |
1Biomedical Engineering, Yale University, New Haven, CT, United States, 2Department of Radiology & Biomedical Imaging, Yale University, New Haven, CT, United States |
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Since acidification of the extracellular environment is a hallmark of cancer pathogenesis, successful therapy may manifest as normalization of pHe. We have shown that quantitative pHe measurement is possible with BIRDS is possible even in the presence of superparamagnetic iron oxide nanoparticles (SPIO-NPs). Because SPIO-NPs have been used to image and track drug delivery, we envisage co-injection of BIRDS agents and NPs, containing drugs and SPIO, as a new protocol that can track drug delivery to tumors, concurrently map tumor location and size (by MRI), and at the same time measure therapeutic efficacy through changes in tumor pH (by BIRDS). |
| Exhibition Hall | Thursday 13:00 - 15:00 |
| 3064 | A novel tracer for non-invasive atherosclerotic plaque phenotyping by PET/MR imaging | |
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, 2Medical Biochemistry, Academic Medical Center, Amsterdam, Netherlands, 3Division of Cardiovascular Diseases, Sulpizio Cardiovascular Center, Department of Medicine, University of California, La Jolla, San Diego, CA, USA., 4Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA |
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Atherosclerotic plaques that rupture can cause stroke or myocardial infarction. Oxidation specific epitopes (OSE), as present in oxidized LDL (OxLDL), are hallmarks of vulnerable plaques . We have developed the PET radiotracer 89Zr-LA25 that targets OSE. Integration of 89Zr-LA25 PET imaging with previous validated techniques enables ‘’vulnerable’’ plaque phenotyping by PET/MRI |
| 3065 | A new highly stable macrocyclic gadolinium complex as a liver targeting MRI contrast agent | |
1BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University, Daegu, Korea, Republic of, 2Medical &Biological Engineering, Kyungpook National University, 3Biomedical Engineering Research Instite, Kyungpook National University, 4Radiology, Kyungpook National University |
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Gd-EOB-DO3A is prepared according to the general synthetic methods, and characterized by spectroscopic analysis. The relaxivities are r1 = 8.07, r2 = 8.57 mM-1s-1. From in vivo T1-weighted MR images, we observe good liver-specific enhancement that can be compared with commercial liver targeting agents, and confirm the biliary excretion via gallbladder. Also the kinetic stability of the gadolinium complex was determined with time-dependent longitudinal relaxation rate (R1,p(t)/R1,p(0)) and the relaxation was maintained above 70% against to initial value during the measurement. |
| 3066 | Highly Sensitive Magnetic Nanoprobe for Detection of ErbB2-expressing Cancer | |
1Department of Radiology, Yonsei University College of Medicine, Seoul, Korea, Republic of, 2Nanomedical National Core Research Center, Yonsei University, Seoul, Korea, Republic of |
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ErbB2, which belongs to the epidermal growth factor receptor (EGFR) family, plays a key role in human malignancies. ErbB2 is overexpressed in approximately 30% of human breast cancers and in many other cancer types, including stomach, bladder, ovarian and lung carcinomas. The objective of this study is the development of anti-ErbB2 aptamer-modified T2 contrast agent based on magnetic nanoprobe (AptErbB2-MNP) having high-specificity onto Erbb2-expressing cancer. For confirmation of AptErbB2-MNP as T2 contrast agent, T2 relaxivity and hydrodynamic diameter was measured. in vitro binding affinity tests were conducted not only recombinant ErbB2 proteins but also the live cells. in vivo targeting ability was verified by in vivo MRI analysis. |
| 3067 | [18F]-DCFPyL standard uptake values correlate with apparent diffusion coefficient and choline measurements on a 3T PET-MRI in prostate cancer | |
1Lawson Health Research Institute, London, ON, Canada, 2Siemens Healthcare Limited, Oakville, ON, Canada, 3Medical Biophysics, Western University, London, ON, Canada, 4Medical Imaging, Western University, London, ON, Canada, 5Oncology, Western University, London, ON, Canada, 6Surgery, Western University, London, ON, Canada, 7Robarts Research Institute, London, Canada, 8London Regional Cancer Program, London, ON, Canada |
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PET data with the [18F]-DCFPyL PSMA-targeted probe to examine prostate cancer in patients scheduled for radical prostatectomy was acquired concurrently with diffusion weighted imaging and chemical shift imaging using a 3T PET-MRI. Standard uptake values (SUV) were compared to apparent diffusion coefficients (ADC) and choline plus creatine over citrate ratios (CC/C). Positive correlations existed between the SUV and CC/C in voxels with low ADC. Negative correlations existed between the ADC and SUV in voxels with high CC/C, and negative correlations also existed between the ADC and CC/C in voxels with high SUV. |
| 3068 | In vitro and in vivo detection of treatment-induced apoptosis using ultrasmall superparamagnetic iron oxide (USPIO)-conjugated Annexin V: A pilot study | |
1Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, 2Innovation Center for Medical Redox Navigation, Kyushu University, 3Meito Sangyo Co., LTD, 4Guerbet Japan KK |
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Apoptosis is involved in many pathological processes. Early detection of treatment-induced apoptosis in malignant tumors is clinically useful for a decision making in therapeutic strategy. Phosphatidylserine (PS) expressed on the cell membrane is known to be a marker of apoptosis which can be detected by probes with Annexin V. In this study, we newly synthesized USPIO-conjugated Annexin V and investigated its potential in the use in apoptosis imaging in both in vitro and in vivo studies. |
| 3069 | A Bright Contrast Labelling Approach for Non-Invasive MR Imaging of Biomaterials | |
1Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada, 2Ted Rogers Centre for Heart Research, Translational Biology & Engineering Program, Toronto, ON, Canada, 3Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada, 4Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada, 5Department of Chemistry, University of Toronto, Toronto, ON, Canada, 6Edward S. Rogers Sr. Department of Electrical & Computer Engineering, University of Toronto, Toronto, ON, Canada |
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Tissue engineered biomaterials have the potential to regenerate almost every tissue type. One difficult aspect to advancing this technology is determining the properties and fate of these materials once introduced in vivo. Non-invasive imaging technology such as MRI holds significant potential for monitoring implanted biomaterials. Few novel approaches to directly image biomaterials have recently been developed; however, most are designed for specific materials or utilize iron oxides with limited specificity. In this study, we investigate a novel approach to labelling biomaterials with a highly efficient T1 agent and a biologically derived adhesive, which allows for accurate and sensitive detection in vivo. |
| 3070 | A Specific MRI contrast agent for glioma: Targeted Quadruple Mutant IL-13 (TQM-13) conjugated liposomes encapsulated with Magnevist@ | |
1Radiology, College of Medicine Penn State University, Hershey, PA, United States, 2Neurosurgery, College of Medicine, Penn State University, Hershey, 3Radiology and Nuclear Medicine Wake Forest School of Medicine, NC, USA |
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There is a clinical need for targeted MRI-contrast agents that are more sensitive and specific in detection of glioma than conventional MRI contrast. We use interleukin-13 (IL-13) as targeting ligand because 75% of glioma cells overexpress IL-13Rα2 significantly1. We investigated the relative efficacy of liposomes conjugated with wild type IL-13 to a variant of IL-13, known as Targeted Quadruple Mutant13 (TQM-13) that has been shown to be more selective for the IL-13Rα2 and binds with higher affinity than the wide type. Our targeted MRI agent, TQM-13-liposomes-Gd, produced specific MRI contrast, delineating tumor, inflamed and normal tissues. |
| 3071 | Metastatic Liver Cancer Targeted Liposomal Theranostic Prodrug for in vivo Diagnosis and Therapy | |
1Bioimaging Research Team, Korea Basic Science Institute, Cheongju-Si, Korea, Republic of |
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Reported here is a new theranostic agent, 1, which consists of a Gd3+-texaphyrin core conjugated to a doxorubicin prodrug via a disulfide bond undergoing cleavage in the presence of glutathione, a species typically upregulated in cancer cells. To improve the solubility and tumor targeting of 1, it was loaded into folate receptor-targeted liposomes to produce FL-1. FL-1 was found to selectively produce a greater anti-proliferative effect in the case of the KB and CT26 cell lines as compared to the HepG2 and NIH3T3 cell lines. FL-1 was also found to provide enhanced MR imaging in vivo under conditions of T1 contrast in the early stage of metastatic cancer progression. |
| 3072 | Compressed Sensing with Signal Averaging Reduces Motion Artifacts in Fluorine-19 MRI | |
1Radiology, University Hospital of Lausanne (CHUV)-University of Lausanne (Unil), Lausanne, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Geneva, Switzerland, 3Advanced Clinical Imaging Technology (HC CMEA SUI DI PI), Siemens Healthcare AG, Lausanne, Switzerland, 4Signal Processing Laboratory 5 (LTS5), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, 5Angiology service, University Hospital of Lausanne (CHUV)-University of Lausanne (Unil), Lausanne, Switzerland |
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In addition to conventional signal averaging, compressed sensing (CS) can be applied to fluorine-19 MRI to improve its low signal-to-noise ratio. For a given acquisition time and CS algorithm, an N-averages N-fold-undersampled dataset results in higher sensitivity than a fully sampled non-averaged dataset. However, it is still unclear whether averaging changes the sensitivity to motion artifacts for an undersampled acquisition.We therefore tested the hypothesis that an N-averages N-fold undersampled acquisition is more robust against motion artifacts than a fully sampled non-averaged acquisition when both are reconstructed with CS. |
| 3073 | Improved tracking and quantification of SPIO-labeled cells using bSSFP with compressed sensing TurboSPI | |
1Biomedical Translational Imaging Centre (BIOTIC), Halifax, NS, Canada, 2Physics, Dalhousie University, Halifax, NS, Canada, 3Diagnostic Radiology, Dalhousie University, Halifax, NS, Canada, 4Microbiology, Dalhousie University, Halifax, NS, Canada |
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Understanding immune cell behaviour is important for evaluating therapeutic response in pre-clinical models. We monitor cell migration in a mouse model of cervical cancer by labeling cells with superparamagnetic iron oxide (SPIO). Simultaneous pre-clinical PET/MRI confirmed that the balanced steady-state free precession (bSSFP) sequence lacks specificity to SPIO-labeled cells within the tumor. We tested TurboSPI, a multi-echo single point imaging technique with compressed sensing that provides high temporal resolution 3D R2* mapping in under 45 minutes. These maps exhibit superior SPIO specificity compared to bSSFP images and enabled us to do both qualitative and quantitative cell tracking. |
| 3074 | ROS imaging by endogenous contrast MRI: specificity and translational premises | |
1Radiology, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States, 2Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 33T Research Program, Center for MR Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States, 4Research Resource Center, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States, 5Radiology, College of Medicine, Northwestern University, Chicago, IL, United States |
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Detection of the elusive Reactive Oxygen Species is pivotal for understanding and diagnosis of many diseases. Recently ROS has been imaged with endogenous MRI contrasts in biological system by reduction in CEST trough combined T1 shortening and proton exchange enhancing effects. We here show potential confounding factors such as H2O2, molecular oxygen, iron oxidation, pH, and temperature to be negligible in phantom studies. In addition, for the first time, we have imaged ROS by endogenous MRI contrasts under physiological conditions, at clinical MRI field strength and on ex vivo brain tissue, paving the path for clinical translation. |
| 3075 | 19F MR-Imaging of acute thrombi using a clinically relevant perfluorocarbon nanoemulsion | |
1Molecular Cardiology, University of Düsseldorf, Düsseldorf, Germany, 2Division of Cardiology, Pulmonology and Vascular Medicine, University of Düsseldorf, Düsseldorf, Germany, 3Pharmaceutical Technology and Biopharmacy, University of Freiburg, Freiburg i. Br. |
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Exact localization of acute thrombi is still a serious problem in the clinical setting. Here we show the feasibility of artefact-free 19F MR-imaging using clinically relevant PFOB-nanoemulsions functionalized with an α2-antiplasmin peptide, specific for early thrombi. Utilizing the isolated CF3-peak of PFOB in combination with a conventional 19F RARE sequence is suitable for specific and artefact-free imaging of acute thrombi in vitro and also in vivo. |
| 3076 | Non-invasive imaging of macrophage accumulation in abdominal aortic aneurysm by 19F MRI | |
1Molecular Cardiology, University of Düsseldorf, Düsseldorf, Germany, 2Department of Internal Medicine/Nephrology, University Hospital Düsseldorf, Düsseldorf, Germany, 3Division of Cardiology, Pulmonology and Vascular Medicine, University of Düsseldorf, Düsseldorf, Germany |
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Abdominal aortic aneurysms (AAA) are a relatively common disease, with still unclear etiology that is associated with high mortality due to aortic rupture. Here we show that mice deficient for the Mas-receptor show aggravated AAA formation upon Ang-II treatment and that accumulation of macrophages in bulk aneurysms can be non-invasively visualized by 1H/19F MRI using intravenously applied perfluorocarbon nanoemulsions which are efficiently phagocytosed by macrophages. We conclude that Mas-receptor deficiency leads to increased inflammation with enhanced AAA formation and that 19F MRI-based inflammation imaging will help to further unravel the role of monocytes/macrophages in the course of AAA progression. |
| 3077 | Selective acidification and de-energization of melanoma xenografts and sensitization to temozolomide | |
1University of Pennsylvania, Philadelphia, PA, United States, 2Thomas Jefferson University, Philadelphia, PA, United States |
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Using 31P magnetic resonance spectroscopy, we have shown that LND selectively lowers the intracellular pH and decreases ATP levels in human melanoma xenografts. Tumor acidification results from inhibition of lactate export via the monocarboxylic acid transporters and inhibition of pyruvate transport and oxidation via the mitochondrial pyruvate carrier. Energetics is further attenuated by inhibition of electron transport at complex II. Under these conditions, temozolomide accumulates in the tumor as a result of decreases in intracellular pH, which inhibits DNA repair by O6-alkyltransferase via conversion to dacarbazine and formation of diazomethane, and also inhibits glutathione-S-transferase that deactivates the reactive alkylating intermediate. |
| 3078 | Detection of metastasis-associated macrophages in the lung, lymph nodes and brain using fluorine-19 based MRI cell tracking | |
1Medical Biophysics, Western University, London, ON, Canada, 2Robarts Research Institute, London, ON, Canada |
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The escape and invasion of cancer cells and the growth of metastatic tumors is in part due to the role of tumor associated macrophages. The macrophages present in these metastatic sites are called metastasis associated macrophages. This study used 19F-based cellular MRI to detect lymph node, lung and brain metastases arising from breast cancer. A custom built 1H/19F birdcage coil allowed for ‘head to toe’ mouse imaging, allowing for detection of 19F agent accumulation, with 1H images verifying anatomical location. This information may be useful in understanding the timing and role of macrophages in the metastatic process. |
| Exhibition Hall | Thursday 13:00 - 15:00 |
| 3079 | In-vivo imaging of glutamine metabolism to the oncometabolite 2-hydroxyglutarate in IDH1/2 mutant tumors | |
1Radiology, Memorial Sloan Kettering Cancer Center, New York City, NY, United States, 2Molecular Pharmacology Program, Memorial Sloan Kettering Cancer Center, New York City, NY, United States, 3Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York City, NY, United States, 4Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York City, NY, United States |
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2-hydroxyglutarate (2-HG) is an oncometabolite that accumulates in various cancers as a result of mutations in the isocitrate dehydrogenase (IDH1/2) genes and can be used as a biomarker for diagnosis. In this work, we demonstrate the fast conversion of glutamine to 2-HG and use it as a basis for developing a 2-HG in-vivo detection method. Using hyperpolarized [1-13C] glutamine and magnetic resonance imaging (MRI), we present the non-invasive unambiguous detection of 2-HG formation with high specificity from glutamine in-vivo and real-time in IDH1 and IDH2 mutant tumors. |
| 3080 | Identifying Immune-Related Metabolic Properties of Pancreatic Cancer via Hyperpolarized Pyruvate Spectroscopic Imaging and NMR Metabolomics | |
1Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, TX, United States, 2Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX, United States, 3Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, United States, 4Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, United States, 5Five Prime Therapeutics, Inc, San Francisco, CA, United States |
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Although immunotherapy presents an attractive new treatment option for patients with pancreatic cancer, its implementation has been underwhelming. As a critical first step in understanding this failure, we have applied hyperpolarized pyruvate spectroscopic imaging and NMR spectroscopy to interrogate the metabolic properties of pancreatic tumors cultivated in the presence of different immune environments. We observed that the immune environment in which a pancreatic tumor is harvested significantly alters metabolic function and that these metabolic differences exhibit a temporal dependence with respect to tumor development. |
| 3081 | Evaluation of the in vivo on-target effect of a newly developed LDH inhibitor using hyperpolarized 13C Magnetic Resonance Spectroscopic Imaging | |
1RBB,UOB/NCI, NIH, Bethesda, MD, United States, 2RBB/NCI, NIH, Bethesda, MD, United States, 3UOB/NCI, NIH, Bethesda, MD, United States, 4National Center for Advancing Translational Sciences (NCATS), NIH, Rockville, MD, United States |
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This study aimed to monitor the impact on metabolic flux in vivo of a newly developed Lactate Dehydrogenase A Inhibitor (LDHI), using hyperpolarized 13C Magnetic Resonance (MR) technology. Using hyperpolarized 13C MR Spectroscopy and Chemical Shift imaging, we found that the LDHI significantly and rapidly suppressed the [1-13C]lactate to [1-13C]pyruvate ratio after single dose administration to mice harboring a MiaPaca (a glycolytic pancreatic cancer cell line) xenograft. These results indicate that the LDHI suppressed lactate production in the tumors. Thus, using Hyperpolarized 13C MRI provides a very useful technology to evaluate in vivo on-target efficacy of LDH inhibitors. |
| 3082 | Study of the Tetracycline-controlled Transcriptional Activation of c-Myc in Burkitt Lymphoma B-cell Line P493-6 Using Hyperpolarized [1-13C]pyruvate | |
1Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany, 2Department of Chemistry, Technische Universität München, Munich, Germany, 3GE Global Research, Munich, Germany, 4III. Medical Department, Klinikum rechts der Isar, Technische Universität München, Munich, Germany |
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We proved that the transcriptional activation of c-Myc expression controlled by tetracycline has a direct influence on lactate dehydrogenase-A (LDH-A) activity in B-cell line P493-6 in vitro. Using hyperpolarized [1-13C]pyruvate and 13C magnetic resonance spectroscopy we were able to monitor a reduction of pyruvate to lactate reaction catalyzed by LDH-A. Incubation of the P493-6 cells in a media with 0.1 μg/mL tetracycline for 24 hours reduced the kinetic value of the reaction by 41.8±10.5 %. This proves that the control of c-myc has a significant influence on LDH-A activity and can be measured using 13C magnetic resonance spectroscopy with hyperpolarized [1-13C]pyruvate. |
| 3083 | Assessment of lactate dehydrogenase activity in renal cell carcinomas using hyperpolarized 13C pyruvate MR | |
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States |
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The incidence of renal cell carcinomas (RCCs) has increased significantly over time due to the widespread use of cross-sectional imaging with incidental cancer detection. RCCs vary widely in histological grade and risk of metastasis. However, current imaging techniques cannot reliably differentiate low grade, indolent RCCs from localized but potentially aggressive RCCs, resulting in the over-treatment of many indolent cancers. Increasing evidence has shown that increased glycolysis with lactate production is a dominant metabolic feature of RCCs. In particular, lactate dehydrogenase expression is positively correlated with RCC grade, and a strong predictor of tumor progression and poor prognosis. Hyperpolarized 13C MR allows real time investigation of cellular metabolism, and provides time-resolved metabolic kinetics that reflects flux through enzyme-catalyzed reactions. The purpose of this study is to investigate whether hypeprolarized 13C pyruvate MR can inform on the LDH activity in orthotopic RCC tumor models. |
| 3084 | Acute renal metabolic effect of metformin treatment assessed with hyperpolarized magnetic resonance imaging | |
1MR Research Center, Aarhus University, Aarhus N, Denmark, 2Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden |
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Metformin is the primary anti-diabetic drug in type-2 diabetes.However, controversy exists on its use in patients with renal impairment.Here we investigated the acute metabolic effects of metformin treatment in rat kidneys,with hyperpolarized 13Cpyruvate and Clark-electrodes.A significantly altered metabolic phenotype was observed 30min post metformin treatment.Anaerobic metabolism was elevated in the cytosol,indicated by increased lactate/pyruvate ratio,and mitochondrial aerobic metabolism was reduced,indicated by decreased bicarbonate/pyruvate ratio.Acute metformin treatment increased renal blood flow with higher O2 saturation and did not change tubular O2 consumption.These results indicate that metformin reduces mitochondrial respiration and enhances anaerobic metabolism,even with enough oxygen supply,within only 30min of treatment. |
| 3085 | Measuring perfusion in a renal ischemic/reperfusion rat model using hyperpolarized α-Trideuteromethyl[15N]glutamine. | |
1MR Research Center, Aarhus University Hospital, Aarhus N, Denmark, 2GE Global Research, Munich, Germany |
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Renal IRI is a leading cause of AKI in several disease states; currently there are several methods to measure renal perfusion in the clinic, but all suffer under specific drawbacks. Here we present a pilot study using the hyperpolarized perfusion marker α-trideuteromethyl[15N]glutamine in a 40 min unilateral ischemia reperfusion rat model. A reduction of 51% in perfusion was observed in the animal. We therefore believe that α-trideuteromethyl[15N]glutamine is a highly promising molecule in renal perfusion studies. |
| 3086 | Assessment of metabolism in early renal ischemia/reperfusion injury using hyperpolarized 13C-pyruvate. | |
1MR Research Center, Aarhus University Hospital, Aarhus N, Denmark |
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Renal IRI is a leading cause of AKI in several disease states; there is a current lack of precise methods to directly assess success of kidney transplant after reperfusion. We here showed how we can measure metabolic function in both the contralateral kidney and post-ischemic 2 min after reperfusion and again after 1 hour of reperfusion. We here saw a very different response compared to metabolic data collected from animals after 24 hours of reperfusion. In this study we induced mild/moderate ischema and it looks like we captured metabolic images in a phase of repair and salvage to maintain normal kidney filtration function in the animals. It seems that severe injury has not yet occurred, or maybe won’t occur. Together with perfusion measurements or kidney filtration measurements this method might hold some clinical value. |
| 3087 | Hyperpolarized Imaging of Lithium-Induced Modulation of [1-13C]Pyruvate Metabolism in the Heart | |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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Lithium is the first-line drug used in bipolar disorder, a chronic psychiatric illness characterized by severe biphasic changes in mood. Lithium has a narrow therapeutic window and has shown cardiac side effects. The present work demonstrates the detectability of lithium induced changes of mitochondrial metabolism in cardiomyocytes by employing hyperpolarized [1-13C]pyruvate magnetic resonance imaging of the in-vivo heart. In healthy rats, lithium is shown to increase mitochondrial metabolism and decrease glycolytic lactate production indicating a potential role of lithium in the heart. |
| 3088 | Influence of Isoflurane Anesthesia on Assessment of Cardiac Metabolism Using Hyperpolarized [1-13C] Pyruvate | |
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland |
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Isoflurane is frequently used in hyperpolarized [1-13C]pyruvate studies. Even though literature suggests direct interaction with mitochondrial metabolism, the influence of the compound on cardiac metabolism has not been assessed in detail yet. In the present study the impact of low versus high isoflurane concentration is examined in a cross-over experiment. Results reveal that cardiac metabolism is modulated by isoflurane concentration showing increased lactate and reduced bicarbonate production during high isoflurane dose relative to low dose. |
| 3089 | Maternal-fetal exchange and metabolism followed in real-time by dynamic hyperpolarized 13C imaging on pregnant rats | |
1Department of Chemical Physics, Weizmann Institute of Science, Rehovot, Israel, 2NeuroSpin Centre CEA Saclay, Gif-sur-Yvette, France, 3Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel |
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Monitoring placental metabolism is of particular interest for the early-detection of complications during pregnancy. This study discusses the use of dynamic nuclear polarization (DNP) enhanced 13C MRSI of hyperpolarized pyruvate, that has been injected into pregnant rats. The enzymatic conversion of pyruvate to lactate was followed in real-time in maternal and fetal compartments –including placentas. Lactate 13C signals in placentas could be observed; they peaked significantly later and were longer-lived than both placental 13C pyruvate and 13C signals in maternal organs. Single-voxel analyses for both metabolites in different organs revealed the T1 relaxation times and kinetics of the Pyr -> Lac transformation. |
| 3090 | Assessing Gas Exchange via Co-Administration of Hyperpolarized [1-13C] Pyruvate and 13C-Bicarbonate | |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States |
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We assess gas exchange in healthy and acutely injured rat lungs by measuring the difference between bicarbonate-to-pyruvate signal-ratio in the right vs. left ventricle of the heart following co-administration of hyperpolarized [1-13C] pyruvate and 13C-bicarbonate. |
| 3091 | Probing metabolic alterations in lung injury during protective and non-protective ventilation using hyperpolarized [1-13C] pyruvate | |
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, United States |
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In this study, hyperpolarized [1-13C]-pyruvate imaging was used to investigate the effect of positive-end expiratory pressure (PEEP) on the stabilization of lung metabolism after injury. Results demonstrated significantly lower lactate-to-pyruvate ratio in rats ventilated with PEEP. |
| 3092 | Hyperpolarized 13C-MRI of DMPO and NAC for evaluating oxidative stress in living animal | |
1National Cancer Institute, Bethesda, MD, United States, 2National Heart, Lung, and Blood Institute, 3National Institute of Neurological Disorder and Stroke |
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5,5-Dimethyl-1-pyrroline-N-oxide (DMPO) is used to detect reactive oxygen species in vitro, and N-acetyl-L-cysteine (NAC) is an antioxidant. We synthesized 13C-labeled DMPO and NAC, and investigated feasibility of hyperpolarized 13C-DMPO and 13C-NAC for evaluating oxidative stress in mice. Hyperpolarized 13C-DMPO and 13C-NAC provided a single peak at 76 ppm and 174 ppm, respectively, and the T1 relaxation time was sufficiently long to apply them for mouse imaging. The signals 13C-DMPO and 13C-NAC were also detected in a mouse body after intravenous injection. The results showed 13C-DMPO and 13C-NAC can be applied to some disease models to evaluate oxidative stress in vivo. |
| 3093 | Enhancing metabolic imaging of energy metabolism in traumatic brain injury using hyperpolarized [1-13C]pyruvate and dichloroacetate | |
1Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States, 2Anesthesiology and the Center for Shock, Trauma, and Anesthesiology Research, University of Maryland School of Medicine, Baltimore, MD, United States |
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We investigated the use of dichloroacetate (DCA) in 13C-pyruvate imaging of traumatic brain injury as a way to improve bicarbonate signal strength and to elucidate changes in pyruvate dehydrogenase activity. Rats were injured with a controlled cortical impact and then injected with 13C-pyruvate before and after administration of DCA. Spectrally-resolved imaging was performed on the brain to quantify the resulting pyruvate, lactate, and bicarbonate signals. The bicarbonate signal and bicarbonate-to-lactate ratio were found to be sensitive to traumatic brain injury, and were affected equally by DCA in injured and uninjured hemispheres of the brain. |
| 3094 | Hyperpolarized [1-13C]-MRI in an ectothermic reptile | |
1Section for Zoophysiology (Department of Bioscience), Aarhus University, Aarhus C, Denmark, 2Comparative Medicine Lab (Department of Clinical Medicine), Aarhus University, Aarhus N, Denmark, 3MR Research Centre (Department of Clinical Medicine), Aarhus University, Aarhus N, Denmark, 4Danish Diabetes Academy, Odense, Denmark |
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Many non-mammalian vertebrates hold enormous potential as “model animals” for various fields of basic physiological and biomedical research. Hyperpolarized magnetic resonance imaging (MRI) can provide quantitative in vivo information about metabolic processes including major pathways of the citric acid cycle and glycolysis via spectral differences of pyruvate intermediates. The combination of [1-13C]-MRI and model animals exhibiting “selected physiological traits” may be a strong tool for gaining novel insights into relevant metabolic mechanisms. In this pilot study we test, for the first time, the application of [1-13C]-MRI in an ectothermic reptile. |