Keywords: Myocardium, Cardiomyopathy

Motivation: The relationship between T2 value and myocardial injury has not been well demonstrated.

Goal(s): To explore the association between T2 value and myocardial injury in HCM patients.

Approach: 50 patients with HCM were prospectively recruited. Hs-cTnI was obtained as a marker of myocardial injury (>0.016ng/mL). ConSept T2 were measured from the maximal value of 16 segments and the middle septum.

Results: The hs-cTnI elevated group had higher T2 global, ConSept T2, T2 max(P<0.05) than the normal hs-cTnI group. The ConSept T2 value were moderately correlated with hs-cTnI(r=0.52, P<0.001). In logistic regression analysis, ConSept T2 value was significantly associated with elevated hs-cTnI(P<0.01)

Impact: This study provided in-vivo evidence by CMR for the ongoing myocardial injury in HCM.

Keywords: Myocardium, Quantitative Imaging

Motivation: Cardiac MR (CMR) imaging is a widely used technique that provides important diagnostic and prognostic information in cardiomyopathy. T1 maps and LGE can provide tissue characterization to detect myocardial fibrosis. 

Goal(s): Our group has developed a 2D free-breathing and self-gated cine and T1 mapping acquisition CAT-SPARCS. This work is to extend the acquisition to 3D T1 mapping. 

Approach: The proposed acquisition is enabled in a single free-running randomized stack of spiral sequence with a 3-minute acquisition and T1 map is reconstructed by dictionary learning method. 

Results: The T1 values from the proposed method are comparable to the clinically standard MOLLI sequence.

Impact: Our technique could substantially shorten the clinical scan time providing both cine and T1 mapping images.

Keywords: Myocardium, Quantitative Imaging, Free-breathing, Multi-parametric Mapping

Motivation: CMR Multitasking has shown promise for non-ECG and free-breathing myocardial T1/T2 mapping in the heart, primarily on a single vendor 3T, but 2D T1-T2 CMR Multitasking has not yet been shown for different vendors (e.g., GE) and field strengths (e.g., 1.5T).

Goal(s): To extend 2D T1-T2 CMR Multitasking to 1.5T and 3.0T GE MR systems.

Approach: We implemented a 2D T1-T2 CMR Multitasking sequence on GE MR systems and evaluated its performance in healthy volunteers and patients at two sites.

Results: 2D T1-T2 CMR Multitasking generated T1 and T2 maps with image quality comparable to the reference measurements. 

Impact: 2D T1-T2 CMR Multitasking provides an efficient and subject friendly (free-breathing, non-ECG) option for quantitative CMR assessment across sites and vendors.

Keywords: Myocardium, Myocardium, cardiac diseases

Motivation: Limited attention has been given to the evaluation of the predictive capacity of T1 mapping in the context of cardiac diseases in the present.

Goal(s): To improve clinical diagnostic precision by integrating T1 value of different AHA segments into the prediction model and find the important AHA segments for cardiac diseases prediction.

Approach: Our study employed nnU-Net to segment T1 mapping images, then to quantify T1 values of AHA segments to establish a hybrid prediction model for some common cardiac diseases.

Results: The results demonstrate that the incorporation of the hybrid prediction model with T1 mapping leads to enhanced performance.

Impact: The added value of T1 mapping enhanced the performance of the common cardiac disease prediction model. It empowered clinicians to identify potential cardiac issues earlier and making clinicians pay more attention to certain AHA segments of the cardiac diseases.

Keywords: Myocardium, Myocardium, deep learning

Motivation: In cardiovascular magnetic resonance, T₁ analysis is generally completed in a manual manner, which is a labor-intensive and time-consuming procedure and could be automated by deep-learning algorithms.

Goal(s): This study aims to develop a deep learning-based technique for directly analyzing T₁ for a T₁ map. 

Approach: We built a cascaded neural network to predict T₁ of the left-ventricle myocardium, septum, blood, and AHA segments and generate LV mask to improve performance. 

Results: The automatic T₁ analysis performed by the proposed approach had good agreement with manual analysis. The mean difference was ~10 ms.

Impact: The proposed approach could automatically estimate the left ventricle, septum, and blood T₁. Along with automatic motion correction and T₁ calculation algorithms, the proposed approach could further simplify and improve the automatization of the workflow of myocardial T₁ mapping examination.

Keywords: Myocardium, Heart, Bright- and black-blood imaging, T1/T2 mapping

Motivation: To overcome the limitations of clinical examinations, which require several sequential acquisitions under multiple breath-holds, and to make cardiac MR more accessible and affordable at lower field strength. 

Goal(s): To develop a novel 3D free-breathing sequence for simultaneous assessment of cardiovascular anatomy via bright- and black-blood imaging and myocardial tissue quantification in an easy to use one-click-scan at 0.55T. 

Approach: Implementation of a novel iNAV-based 5-heartbeat interleaved sequence (proACTION) with distinct IR and T2 preparation modules and non-rigid motion correction at 0.55T. 

Results: proACTION provides good delineation of cardiac and vascular structures with accurate joint T1/T2 parametrical mapping in healthy subjects.

Impact: Comprehensive 3D whole-heart evaluation of cardiovascular anatomy and tissue characterization with T1/T2 maps can be obtained in an efficient, free-breathing, and easier to use one-click-scan with proACTION at 0.55T.

Keywords: Myocardium, Radiomics

Motivation: Pulmonary regurgitation (PR) severity is an important prognostic indicator in repaired Tetralogy of Fallot (rTOF) patients. Radiomics analysis may reveal hidden information about cardiomyopathy in these patients.

Goal(s): This study aimed to develop a radiomics-based classification model by native T1 mapping to identify rTOF patients with moderate-to-severe PR and severe PR.

Approach:  A total of 623 radiomic features were extracted from native T1 mapping. We used machine learning for feature selection to identify the best radiomic features that maximize the diagnostic value for classifying cardiac diseases.

Results: Optimal performance was achieved in the proposed segmental mid-slice T1 mapping model.

Impact: The segmental mid-slice radiomics of native T1 mapping showed better classification performance than conventional native T1 values in identifying rTOF patients with moderate-to-severe PR and severe PR. The discerned tissue characteristics offered additional physiopathological information beyond native T1 values.

Keywords: Myocardium, Cardiomyopathy, T1mapping;feature tracking;strain

Motivation: Left ventricular hypertrophy（LVH）is a common manifestation of many cardiac diseases, including myocardial amyloidosis (CA), hypertrophic cardiomyopathy (HCM), among others. Clinical diagnosis of the etiology of LVH has some difficulties

Goal(s): Differences in myocardial T1 values and left atrial strain between CA and HCM patients remain unclear

Approach: In this study, T1mapping and feature tracking based on left atrial were applied to identify CA and HCM

Results: Results illustrated that  T1 values and left atrial strain were significantly different between CA and HCM. T1 mapping combined with left atrial reservoir function (Εs) could effectively distinguish CA from HCM.

Impact: T1mapping and feature tracking techniques, as emerging imaging techniques in cardiac magnetic resonance(CMR) in recent years, have been widely used in the study of various myocardial diseases because they do not require the injection of contrast agents.

Keywords: Myocardium, Quantitative Imaging, T1 Map,Deep Learning,MOLLI

Motivation: To overcome limitations of prolonged acquisition and breath-hold(BH) times in Cardiac Magnetic Resonance Imaging (CMR), specifically  MOLLI  sequence, enhance patient comfort and compliance.

Goal(s): Aimed to validate MyoMapNet sequence with inline reconstruction against the standard MOLLI protocol, focusing on image quality and T1 measurement accuracy, reducing scan time and BH durations.

Approach:  20 subjects were imaged using  two sequences. Image quality was assessed via edge sharpness and signal intensity ratios,T1 accuracy was determined through myocardial segment analysis.

Results: MyoMapNet achieved comparable image quality and T1 accuracy to MOLLI  with shorter acquisition times, demonstrating no significant difference in myocardial and blood pool T1 values.

Impact: MyoMapNet offers a rapid and reliable alternative for myocardial T1 mapping, reducing scan time and heart rate dependence, which can improve patient throughput and comfort in clinical CMR workflows. Future studies will expand to post-contrast T1 values and ECVs.

Keywords: Myocardium, Myocardium

Motivation: Deep-learning algorithm has the potential to alleviate the impaction from motion in myocardial T₁ mapping. However, there is no ground truth for the training.

Goal(s): The aim of this study is to develop a deep learning-based algorithm to correct motion in myocardial T₁ mapping using a self-supervised manner.

Approach: We proposed a deep-learning approach and trained it using synthesized reference from the input T₁-weighted images, eliminating the need for ground truth.

Results: Our results indicated that a self-supervised deep-learning approach could align the left-ventricle myocardium and therefore improve the T₁ map quaintly and accuracy.

Impact: A self-supervised deep-learning approach could automatically perform motion correction for cardiovascular magnetic resonance T₁ mapping, alleviating the impaction from motion and improving the quality of pixel-wise T₁ map.

Keywords: Myocardium, Cardiomyopathy, T1 mapping, entropy, fibrosis

Motivation: Cardiac T1 maps are a promising choice for texture analysis due to their pixel values originating from fitting, making them less prone to variations. Entropy of T1 map as a measure of myocardial tissue heterogeneity may reflect the disruption of myocardial fiber structure and/or the infiltration of extracellular matrix. 

Goal(s): We aim to investigate the relationship between myocardial tissue properties and diastolic function, as well as myocardium stiffness.

Approach: We applied TA on native T1 maps of a pressure-overload rat model 12 weeks after the operation.

Results: Entropy exhibited a strong correlation with both chamber stiffness and diastolic function biomarkers.

Impact: Our data indicates that impaired diastolic function may be due to disorganized/disrupted myocardium, rather than increased fibrosis solely. Our research sheds new light on understanding the relationship between extracellular matrix  and cardiac function.

Keywords: Myocardium, Cardiovascular, Extracellular volume fraction (ECV)

Motivation: Extracellular volume (ECV) is an emerging biomarker for diffuse fibrosis, which is known to be particularly challenging to detect. Existing methods are limited to single-slice acquisition with or without breath-hold.

Goal(s): To develop a new method for free-breathing, 3D ECV mapping of the whole heart.

Approach: 3D cardiac T₁ mapping was performed before and after contrast agent injection using a free-breathing, ECG-gated IR-FLASH sequence followed by a linear tangent space alignment model-based image reconstruction.

Results: The estimated ECV values from the proposed method were comparable to those from the reference MOLLI method.

Impact: The proposed method allows for free-breathing, 3D ECV mapping of the whole heart in a practically feasible imaging time. The proposed method is potentially useful ECV quantitation in healthy and diseased populations with diffuse fibrosis.

Keywords: Myocardium, Quantitative Imaging, HCM

Motivation: The presence of myocardial fibrosis in HCM has significant prognostic power in the prediction of severe cardiac complications in HCM.

Goal(s): To compare native T1、ECV and myocardial strain parameters in patients with LGE-negative HCM with healthy participants to evaluate for the presence of subtle myocardial fibrosis and regional myocardial function in HCM. 

Approach: Seventeen patients with LGE-negative HCM and twenty-eight healthy participants were underwent the MRI scan and the quantitative parameters were analyzed.

Results: Overall native T1 and ECV values were increased in HCM patients ; GLS, GRS, and GCS were all decreased in HCM patients with LGE negative.

Impact: The cardiac magnetic resonance T1 mapping technique combined with the feature tracking technique can reflect subtle myocardial fibrosis, myocardial deformation, and impaired myocardial systolic function earlier in HCM patients from LGE negative patients.

Keywords: Myocardium, Cardiomyopathy, myocardium/T1Mapping

Motivation: Myocardial T1-mapping is a widely used quantitative method to evaluate the characteristics of myocardium. Commonly, the cardiac trigger delay (TD) during the diastolic phase depends on the settings of the system. However, because myocardial characteristics can affect both diastole and systole, acquiring T1 mapping at various cardiac phases may have clinical significance.

Goal(s): To acquire cardiac T1 mapping at various cardiac phases in one scan.

Approach: Dynamic trigger delay

Results: The proposed technique was successfully implemented. Application of image registration technique has improved the accuracy of T1 value quanitification.

Impact: CINE T1 mapping can acquire quantitative mapping of several different cardiac phases simultaneously in one scan; it may be useful for more detailed diagnosis of myocardial properties.

Keywords: Myocardium, Heart, Transplant, T1-mapping, T2-mapping, ECV, Rejection, Calibration

Motivation: Acute rejection is the leading cause of death in pediatric heart transplant (PHTx) recipients. Endomyocardial biopsy is currently required to monitor for rejection. Quantitative cardiac magnetic resonance (CMR) is a potential non-invasive monitoring tool, with T2, T1, and ECV mapping providing information about fibrosis and edema. However, measurements vary between sites. 

Goal(s): To measure inter-site/temporal variability and calibrate multisite PHTx CMR data.

Approach: We investigated manganese-chloride solution cardiac phantom T2 and T1 repeatability and inter-site variation, and impact of calibration on PHTx data.

Results: Calibration reduced inter-site variability in phantom and PHTx measurements.

Impact: Our preliminary results illustrating inter-site variation in CMR-relevant phantom T2 and T1 measurements support the need for inter-site calibration when multi-center trials are conducted using CMR parametric imaging (T2, T1, and calculated ECV).

Keywords: Myocardium, Heart, LGE

Motivation: Free breathing motion-corrected late gadolinium enhancement (FB-MOCO-LGE) is commonly used for scar assessment in patients unable to breathhold. Reduction of FB-MOCO-LGE scan time will contribute reducing overall examination time and cost.

Goal(s): To evaluate the potential of simultaneous multi-slice (SMS) imaging in reducing FB-MOCO-LGE acquisition time while maintaining image quality.

Approach: To Implement a 2x SMS-bSSFP technique with phase-sensitive inversion recovery (PSIR) reconstruction. Evaluation of FB-MOCO-LGE and SMS FB-MOCO-LGE was conducted on 20 patients.

Results: The SMS approach demonstrated a significant two-fold reduction in acquisition time without compromising myocardial sharpness or signal-to-noise ratio and minimal impact on image quality.

Impact: SMS-enabled FB-MOCO-LGE enables halves acquisition time with minimal on image quality. Therefore, this approach show promise for reducing LGE protocol duration and cost of cardiac MRI examination.

Keywords: Myocardium, Myocardium, Late Gadolinium Enhancement , infarction

Motivation: Low-field wide-bore MRI scanners are cost-effective but suffer from lower SNR, impacting myocardial LGE image quality.

Goal(s): To introduce and evaluate a novel imaging strategy that offers full heart coverage and reduces image count by 50%.

Approach: Developed a sequence acquiring 45-55 overlapped short-axis 2-D slices with patch-based motion compensated filtering to enhance SNR.

Results: The new technique improved SNR in whole heart coverage LGE imaging at 0.55T, though further studies with scarred myocardium are needed.

Impact: This study advances cardiac MRI by demonstrating that a novel LGE imaging technique coupled with MC-KW patch filtering substantially enhances SNR in low-field wide-bore scanners, promising improved myocardial scar detection at reduced costs.

Keywords: Myocardium, Cardiovascular

Motivation: The 3D fusion of coronary structure and myocardial blood flow data helps to reduce the misallocation of affected vessels to their associated myocardial territories.

Goal(s): An AI-based pipeline has been developed that uses advanced machine learning algorithms to automatically fuse images from cardiac CTCA and perfusion MRI.

Approach: The pipeline includes an automatic reorientation of 3D CT coronary angiography and fusion with stress cardiovascular magnetic resonance images.

Results: we achieved 3D fusion of CTCA and CMR establishing a correlation between coronary artery stenosis and stress-induced myocardial hypoperfusion.

Impact: the pipeline can assist in clinical assessments of coronary artery disease.

Keywords: Myocardium, Machine Learning/Artificial Intelligence

Motivation: Although late Gadolinium Enhancement (LGE) imaging is widely used for diagnosing myocardial infarction (MI), contrast-free approaches are in need for patients with gadolinium contraindications.

Goal(s): To develop Cine Generated Enhancement (CGE), a novel technique that uses contrast-free cine images to predict images resembling LGE.

Approach: A deep generative model was trained to translate cine images into LGE images of acute MI exploiting the different motion dynamics between heathy and infarcted myocardium.

Results: Realistic enhancement images can be generated for acute MI patients using cine images unseen during training. The scar size and transmurality estimated with CGE agreed well with LGE.

Impact: This study presents an effective, non-invasive, and contrast-free method for predicting LGE in acute MI, potentially reducing the use of gadolinium-based contrast agents and shortening cardiac MR examinations.

Keywords: Atherosclerosis, Low-Field MRI, Late gadolinium enhanced

Motivation: 3D whole-heart late gadolinium enhancement imaging has previously been demonstrated at 1.5T, but not at low-field (0.55T).

Goal(s): To develop a novel free breathing, whole-heart, late gadolinium enhancement imaging framework at low field.

Approach: Patients with known ischaemic heart disease were scanned and results of the proposed 3D sequence were compared with 2D LGE images.

Results: There is excellent agreement between the 3D and 2D datasets in the detection of myocardial scar.

Impact: Preliminary results demonstrate the feasibility of the proposed framework for comprehensive 3D whole-heart late gadolinium enhancement imaging for the detection of myocardial scar at 0.55T. 

Keywords: Myocardium, Cardiovascular

Motivation: Coronary Arterial Disease (CAD) evaluations often require myocardium perfusion exams. Many CAD patients also have stents which makes difficult to evaluate images due to susceptibility artifacts. A reliable non-contrast MR perfusion technique in CAD patients with stents is needed. 

Goal(s): To introduce Time-SLIP technique with Stack-of-Stars (SoS) sequence for more inclusive myocardial assessments without the need for contrast mediums.

Approach: Implemented diaphragm navigator echoes and T2-prep with the SoS sequence, refined through phantom trials, for tagging the proximal aortic root blood flow to visualize myocardial perfusion.

Results: Preliminary in-vivo scans indicate reduced stent-related artifacts and the feasibility of non-contrast perfusion quantification.

Impact: Our non-contrast myocardial perfusion approach offers a safer CAD evaluation, reducing risks from contrast agents. This method opens doors for inclusive patient assessments and encourages further refinement in non-invasive cardiac diagnostics.

Keywords: Myocardium, Cardiomyopathy

Motivation: CMR first-pass-perfusion imaging (FPI) had revealed coronary microvascular dysfunction (CMD) in dilated cardiomyopathy (DCM). However, it’s unknown if FPI could predict left ventricular reverse remodeling (LVRR) in DCM.

Goal(s): Investigating the value of FPI parameters for predicting LVRR.

Approach: 94 DCM patients and 35 healthy controls were enrolled. FPI as well as the left ventricular structure, function and late gadolinium enhancement (LGE) parameters were analyzed. 

Results:  FPI showed more serious CMD in non-LVRR than LVRR. Time_max of FPI as well as left ventricular remodeling index and LGE extent were independent predictors.

Impact: This study firstly showed the role of FPI in predicting LVRR in DCM.

Keywords: Myocardium, Cardiovascular

Motivation: 2D high-resolution late gadolinium enhancement (LGE) imaging can benefit from shorter scan times. Current acceleration techniques lead large signal-to-noise (SNR) penalties, reducing diagnostic quality while longer breath-holds increases scan time and makes the imaging susceptible to artifacts. 

Goal(s): To assess the feasibility of a rapid 2D LGE imaging using Resolution Enhancement Generative Adversarial Inline Neural Network (REGAIN).

Approach: Images were acquired with 3.3 and 5.7-fold accelerations, reconstructed using REGAIN, and compared with 1.8-fold GRAPPA acceleration. 

Results: REGAIN successfully improved visual image sharpness in LGE images acquired with 3.3-fold (~6-second) and 5.7-fold (~10-second) accelerations. Image quality was comparable to 1.8-fold (~16-second) GRAPPA acceleration.   

Impact: REGAIN enables accelerated LGE imaging with significantly reduced breath-hold duration. 

Keywords: Heart Failure, Cardiomyopathy, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)

Motivation: Late gadolinium enhancement (LGE) CMR‘s wider clinical adoption is hindered by its prolonged wait time and imaging protocol dependence.

Goal(s): Develop a delayed dynamic contrast enhancement (dDCE) model to shorten the LGE wait time and provide a quantitative characterization of the myocardium contrast washout process.

Approach: Dynamic T1 maps were acquired in the contrast washout period in dogs with myocardial infarctions. dDCE maps and synthesized LGE images were derived from data collected within 5-minute post-contrast injection.

Results: The 5-minute dDCE maps provide physiologically reasonable measurements and comparable myocardial viability assessment ability to standard LGE images.

Impact: The shortened LGE wait time from the quantitative dDCE maps may benefit patients unable to tolerate long CMR examination time and open new dimensions for quantitative myocardium viability assessment.

Keywords: Myocardium, Cardiovascular

Motivation: To overcome the limitations of LGE imaging, including respiratory motion artifacts and lengthy scan times, while enhancing myocardial scar imaging.

Goal(s): To develop a deep learning-based free-breathing single-beat LGE. 

Approach: Free-breathing single-beat low-resolution 2D LGE images are acquired and followed by resolution enhancement generative adversarial inline neural network (REGAIN) to enhance the spatial resolution. Each slice was acquired in a single beat, followed by one beat for signal recovery. The entire left ventricular dataset was acquired in 20 heartbeats.

Results: REGAIN improved image sharpness and quality of single-beat 2D LGE acquired with 4.7-fold acceleration with spatial resolution of 1.5 × 5 mm².  

Impact: A rapid single-beat 2D LGE imaging can reduce CMR scan time, increase patient comfort, and reduce sensitivity to breathing motion. 

Keywords: Atherosclerosis, Cardiovascular, Myocardial Perfusion

Motivation: Model-based quantitative myocardial perfusion MRI is feasible. However, few studies have investigated its diagnostic accuracy in detecting significant coronary artery disease (CAD).

Goal(s): To evaluate the diagnostic accuracy of quantitative stress myocardial perfusion MRI using Patlak plot method for the detection of significant CAD.

Approach: Myocardial blood flow (MBF) and myocardial flow reserve (MFR) determined by Patlak analysis of stress perfusion MRI with LV blood saturation correction were compared with fractional flow reserve.

Results: Model-based quantitative stress perfusion MRI has a high diagnostic accuracy for detecting significant CAD with the AUC of 0.739 and 0.745 for stress MBF and MFR, respectively.

Impact: Absolute quantification of myocardial blood flow and myocardial flow reserve by stress-rest myocardial perfusion MRI with model-based approach permits accurate and objective assessment of myocardial ischemia due to flow-limiting obstructive coronary artery disease, which can aid daily routine clinical practice.

Keywords: Myocardium, Myocardium, hemorrhage, intramyocardial hemorrhage, myocardial infarction, ischemia-reperfusion injury, ischemia , animals, blood, blood vessels, cardiovascular, contrast agents, contrast mechanisms, heart, novel contrast mechanism, preclinical

Motivation: Intramyocardial hemorrhage (IMH) frequently occurs in acute myocardial infarction (AMI) and is associated with adverse outcomes.  While T₂* cardiac magnetic resonance (CMR) imaging has emerged as the reference standard for noninvasive IMH detection, it relies on the paramagnetic properties of hemoglobin breakdown products, usually detectable between 1 and 3 days following IMH.  

Goal(s): We demonstrate an alternative approach that can more promptly detect active myocardial bleeding.

Approach: We leveraged the T₁ shortening effects of intravascular ferumoxytol to identify IMH following acute ischemia-reperfusion injury.  

Results: Ferumoxytol-enhanced CMR depiction of IMH were in agreement with gross and histologic evaluations.

Impact: We demonstrate the effectiveness of ferumoxytol-enhanced cardiovascular magnetic resonance (FE-CMR) in detecting active intramyocardial hemorrhage after ischemia-reperfusion injury.  This may facilitate the development, testing, and clinical adoption of strategies to mitigate IMH-associated complications.

Keywords: Myocardium, Cardiovascular

Motivation: Traditional bright-blood late gadolinium enhancement (BB-LGE) technique often obscures the visualization of endocardial LGE. In contrast, black blood technique overcomes this limitation but sacrifices contrast between the myocardium and blood pool.

Goal(s): By selecting specific TI (inversion time) values, gray blood images can be generated to achieve the desired contrast among the blood pool, myocardium, and scar tissue.

Approach: We conducted a comparative analysis of image quality, diagnostic confidence score, detection of delayed enhancement lesions, and the contrast-to-noise ratio (CNR) between BB-LGE and GB-LGE.

Results: The implementation of GB-LGE  enhances diagnostic confidence and improves CNR between the blood pool and myocardial scar tissue.

Impact: The proposed GB-LGE sequence in this study enhances scar detection rates and diagnostic confidence, addressing limitations associated with equipment and technology. It optimizes clinical workflow efficiency while offering a universal approach with potential for widespread adoption.

Keywords: Myocardium, Myocardium, noncontrast, perfusion, deep learning

Motivation: Cardiac arterial spin labeling (ASL) method is sensitive to noise (system and physiology), which may lead to inaccurate MBF measurement.

Goal(s): A cardiac MRI arterial spin labeling method was developed with assistance of a deep learning networks (DeepCASL) to improve image quality and measurement accuracy.

Approach: The performance of the DeepCASL method was evaluated in a canine model of coronary arterial disease by comparing and correlating with MBF determined by microsphere measurements.

Results: The validation study revealed moderate to strong correlations in absolute myocardial blood flow values between MRI and microsphere reference methods.

Impact: This new DeepCASL technique opens a door for clinical applications of noncontrast cardiac perfusion as a screen tool for reliable diagnosis of perfusion deficit in a variety of cardiomyopathy disorders.

Keywords: Myocardium, Perfusion, Simultaneous multi-slice, myocardial blood flow

Motivation: While simultaneous multi-slice (SMS) excitation has been proposed to increase the myocardial coverage for cardiac perfusion MRI, its influence on the quantification of myocardial blood flow (MBF) has not been evaluated. 

Goal(s): To determine whether SMS with multiband factor of two preserves accuracy in the quantification of MBF compared with the corresponding perfusion MRI with single-slice excitation. 

Approach: We prospectively enrolled six patients and performed standard and SMS perfusion MRI back-to-back and calculated the arterial input function (AIF) and resting MBF.

Results: Both the AIF and MBF values calculated from the datasets acquired with the two perfusion sequences were comparable.

Impact: This study demonstrates feasibility of utilizing a 2D simultaneous multi-slice (SMS) (multiband factor = 2) perfusion sequence to increase the myocardial coverage and quantify the myocardial blood flow to help coronary artery disease diagnosis.

Keywords: Myocardium, Heart, Myocardial infarction，Patch，Cardiac magnetic resonance

Motivation: Evaluation of therapeutic effect of myocardial infarction（MI） patch using cardiac magnetic resonance （CMR） imaging

Goal(s): Cooperation between medicine and polymer science

Approach: We made a pig model of MI. The MI pigs in the patch group attached the patch to the epicardial side, while the MI pigs in the control group were not treated. We performed CMR imaging before operation, 2 weeks and 8 weeks after modeling. Finally, the heart was taken for pathological verification.

Results: Compared with the control group, the patch group pig had thicker ventricular wall, better cardiac function and smaller LGE%. Histology and imaging correspond well.

Impact: By non-invasively analyzing the heart's structure and function, CMR helps us evaluate the potential of using patches to treat MI and offers valuable insights for preventing ventricular aneurysms after heart attacks in clinical practice.

Keywords: Myocardium, Perfusion

Motivation: While extensive research has explored robust pixel-wise quantification of myocardial blood flow, there is also a need for further investigation into accurate myocardial signal delay estimation, given its diagnostic value, for enhancing conventional clinical myocardial perfusion protocols.

Goal(s): We seek to address the primary challenges in calculating delay and improve its estimation accuracy.

Approach: We introduce a deep learning approach designed to recognize motion artifacts as outliers along the temporal signal curve of each voxel, subsequently eliminating them from the perfusion quantification process. 

Results: Our findings suggest that eliminating outliers enhances the accuracy of perfusion delay parameter estimation in scenarios with residual motion.

Impact: Enhancing the precision of delay estimation will increase its diagnostic value as a biomarker, offering crucial insights into the identification of perfusion defects in ischemic hearts. 

Keywords: Myocardium, Cardiovascular, Contrast Mechanism, ihMT

Motivation: Imaging the cardiac conduction system (CCS) remains a significant challenge, since no imaging modalitiy has so far provided good contrast between the cardiac muscle and the embedded fibers that regulate normal heartbeat.

Goal(s): We aim to address this challenge by employing inhomogeneous Magnetization Transfer Imaging (ihMT).

Approach: We hypothesise that the conductive fibers exhibit unique dipolar order properties, due to the collagen sheath that surrounds them, and could thus be selectively isolated by ihMT.

Results: As a first step towards enhancing muscle-to-fiber contrast, this work investigated the biophysical parameters that govern the ihMT signal in the macromolecular environment of the CCS.

Impact: The assessment of the macromolecular environment of the cardiac conduction system (CCS) allows for a better understanding of its morphological architecture, and will enable us to design an ihMT sequence specifically sensitive to the challenging morphology of the CCS.

Keywords: Arrhythmia, Precision & Accuracy, cardiac and respiratory self-gating

Motivation: ECG-gating for cardiac MR Imaging may fail, especially at high field, and the conventional self-gating method is insufficient to effectively extract the cardiac signal in 3D cardiac MR cine with high precision (previous precision 20-30ms).

Goal(s): Our goal was to achieved a reliable cardiac self-gating technique with the precision of 10ms level.

Approach: We proposed a two-step selective PCA self-gating method by first selecting the heart beating or respiration sensitive points and then performing PCA.

Results: The proposed method achieved a temporal precision of 11ms for 3D cardiac cine images.

Impact: The proposed selective PCA self-gating technique can be applied in poor ECG-gating MR scans, such as patients with hairy chests or obesity, as well as in high-field environments, with a high level of precision down to 11ms.

Keywords: Arrhythmia, Arrhythmia, Fibrosis

Motivation: The impact of vendors and threshold methods on quantification of LA fibrosis is not well studied.

Goal(s): To evaluate the inter-vendor and inter-threshold impact on LA fibrosis quantification.

Approach: Both packages of Medis and CVI⁴² ADAS were used to calculate LA fibrosis based on the image IIR 1.2-method and 2 SD above the mean blood pool signal intensity of LA.

Results: The both post-processing software packages of Medis and CVI⁴² ADAS have a good agreement and correlation to quantify LA fibrosis if an identical quantification method was used. However, LA fibrotic burden is influenced by used quantification methods.

Impact: LA fibrotic burden quantified with cardiac MRI is influenced by used quantification methods, but don’t dependent on vendors. The use of Utah stages by other centers needs further validation when different analysis methods applied.

Keywords: Arrhythmia, Magnetization transfer

Motivation: The architecture of the cardiac conduction system is implicated in cardiac arrhythmias such as ventricular fibrillation and characterizing this structure will help better understand and diagnose these arrhythmias.

Goal(s): Optimizing the inhomogeneous magnetization transfer technique for 3D imaging of conducting fibers.

Approach: A range of parameters for ihMTRARE sequence were explored for imaging samples from sheep’s left ventricles containing free-running Purkinje fibers and myocardium.

Results: Across samples, ihMTR signal was found consistently higher in fibers compared to the myocardium for the chosen saturation parameters. This finding holds promise for future 3D imaging of the cardiac conduction system.

Impact: The results of this study hold promise for future 3D imaging of larger samples of the left ventricle containing free-running and intramural Purkinje fibers using the optimized sequence which would allow the segmentation and characterization of these fibers.

Keywords: Arrhythmia, Arrhythmia

Motivation: Irregular cardiac motion can degrade image quality and preclude the use of conventional segmented cine MRI for quantitative evaluation of cardiac function. And it can be difficult for some patients to do multiple breath holds. 

Goal(s): To evaluate a cluster-based algorithm and reconstruction approach for cine MRI in patients with atrial fibrillation under free-breathing condition.

Approach: Ten atrial fibrillation patients were scanned under breath-held and free-breathing conditions. Image quality, SNR, CNR, and edge sharpness were assessed. 

Results: No significant difference in image quality scores, SNR, CNR, and edge sharpness were found for images obtained under breath-held and free-breathing conditions. 

Impact: Adaptive cluster-based motion binning with temporal total variation reconstruction is effective at handling irregular cardiac motion and enables high quality, free-breathing cine MRI in patients with atrial fibrillation.   

Keywords: Arrhythmia, Arterial spin labelling, Atrial Fibrillation

Motivation: Cerebral hypoperfusion may be a major link between atrial fibrillation (AF) and neuropathologic processes. Whether catheter ablation can effectively improve cerebral perfusion needs to be evaluated  by noninvasive methods.

Goal(s): To assess the effects of catheter ablation on overall and regional cerebral blood perfusion in AF patients using multi-delay ASL.

Approach: Multi-delay ASL was performed before and after catheter ablation to calculate arterial transit time and cerebral blood flow. Whole and regional cerebral perfusion parameters before and after ablation were characterized and compared in paroxysmal and non-paroxysmal groups.

Results: Cather ablation significantly increased overall and regional cerebral blood perfusion, especially in non-paroxysmal AF.

Impact: Catheter ablation can improve cerebral perfusion and maintain brain health, which should be considered even in asymptomatic patients. Multi-delay ASL can be used to evaluate and monitor cerebral perfusion in AF and help with patient screening and therapeutic strategy development.

Keywords: Arrhythmia, Arrhythmia, CMR,4D FLOW

Motivation: A novel imaging method was developed to diagnose children with premature ventricular contractions (PVCs), thereby preventing heart failure or cardiomyopathy.

Goal(s): To determine the changes in the blood flow composition of LV in children with PVCs, a free breathing 4D flow CMR was performed. The relationship of PVC load with LV function was explored.

Approach: The children with PVCs underwent 24-hour dynamic ECG and CMR examination within 3 days. Thus, we determined their cardiac function and hemodynamic parameters.

Results: Children with PVCs had reduced direct blood flow in LV, which showed a significant negative correlation with PVC load.

Impact: In this study, we analyzed the characteristics of the left ventricular blood flow in children with premature ventricular contractions (PVCs). Thereafter, we elucidated the pathophysiological mechanism of PVCs, which provided the basis for clinical treatment and prognostic evaluation.

Keywords: Arrhythmia, MR-Guided Interventions, Arrhythmia, Low-field MRI

Motivation: The 12-lead ECG is the standard diagnostic for monitoring rhythm and ischemia during stress. ECG distortion via magnetohydrodynamic effect is proportional to field strength and limits interpretation at 1.5T and 3T. Lower field (0.55T) offers potential improvement.

Goal(s): Compare variability in ECGs in at 0.55T, 1.5T and 3.0T and examine changes in ECG morphology at 0.55T in response to ischemia and exercise stress.

Approach: ECGs were recorded in: (1) swine at three fields, and at 0.55T during ischemia, and (2) normal human subjects a and during ergometer stress.

Results: At 0.55T ECGs remained interpretable at isocenter though some distortion due to MHD persisted.

Impact: Low field (0.55T) MRI can provide improved clinical interpretation of 12-Lead ECGs at isocenter due to reduction of magnetohydrodynamic distortion and reduced sensitivity to patient motion as demonstrated in swine with cardiac ischemia and humans undergoing exercise induced stress.

Keywords: Arrhythmia, Arrhythmia, Atrial fibrillation (AF); Cardiac magnetic resonance (CMR); Three-dimensional late gadolinium enhancement (3D-LGE); Left atrial fibrosis (LAF)

Motivation: Left atrial (LA) function and structural remodeling in atrial fibrillation (AF) remains uncertain in the context of LA-CMR.

Goal(s): To investigate the effectiveness of 3D-LGE CMR and LA-strain techniques for assessing LA fibrosis in paroxysmal or persistent AF (PaAF, PeAF) patients.

Approach: Preoperative CMR was used to analyze LA-strain parameters. Quantitative assessments of LA wall enhancement utilized the Infarct-to-Interstitial Ratio (IIR) as a reference.

Results: Contrasted with PaAF, those with PeAF exhibited increased LA volumes, reduced LA function, and lower strain values. In 3D-LGE sequences, PeAF patients demonstrated more extensive myocardial enhancement, scar tissue, and interstitial fibrosis in comparison to PaAF patients.

Impact: Our research provides a promising imaging tool for the management of AF patients, with potential translational applications focused on quantitatively and visually assessing LA function and structural remodeling, personalizing treatment, assisting intraoperative navigation, and enabling long-term monitoring. 

Keywords: Arrhythmia, Visualization

Motivation: Standard ECG-gated breath-held (BH) cine MRI often produces non-diagnostic image quality in CIED patients who have a high burden of arrhythmia. 

Goal(s): The goal of this study is to produce diagnostic images using a free-breathing real-time cine MRI for those patients.  

Approach: We proposed a new pulse sequence to meet our goal. 

Results: Our proposed pulse sequence produced clinically acceptable images and accurate bi-ventricular and functional parameters compared with standard BH cine in patients with a CIED.

Impact: Our proposed pulse sequence will be useful for a shorter overall scan time while maintaining a diagnostically acceptable images in all CIED patients. 

Keywords: Arrhythmia, Arrhythmia

Motivation: This study aimed to explore the feasibility and accuracy of Sonic DL cardiac magnetic resonance cine technology.

Goal(s): We aimed to assess the performance of Sonic DL cine MRI at 3T for left ventricular (LV) volume and mass measurement, especially patients with arrhythmia and/or difficulty in breath-holding.

Approach: 48 patients were consecutively enrolled.  EDV, ESV, SV, EF, and LV mass were measured. The agreement and correlation of the parameters were assessed. Image quality was evaluated  and structure visibility rating.

Results: Good agreements and correlations were found between the techniques for measuring left ventricular function.

Impact: Sonic DL cardiac cine MRI allowed the assessment of LV volume with high accuracy and showed a significantly better image quality.

Keywords: Myocardium, Cardiovascular, Connective tissue disease, Serum uric acid, Hypouricemia, Cardiovascular resonance magnetic imaging, Feature tracking, Right atrial strain.

Motivation: To explore a common and low-cost indicator in patients with connective tissue disease (CTD) to determine the subclinical right cardiac chamber remodeling

Goal(s): Investigated the association of Serum uric acid (SUA) with right cardiac chamber remodeling assessed by cardiac magnetic resonance feature-tracking (CMR-FT) in CTD patients. 

Approach: All individuals underwent CMR examinations and their SUA levels were recorded. CMR-FT was used to evaluate the right atrial and ventricular strain parameters. 

Results: CTD patients had significantly right cardiac chamber remodeling and elevated SUA levels compared with controls. SUA may be a potential risk factor of right cardiac chamber remodeling in CTD patients.

Impact: Right heart remodeling is widespread in CTD patients. SUA is considered a potential independent risk factor for cardiovascular disease and elevated SUA levels are often observed in CTD patients. 

Keywords: Myocardium, Myocardium

Motivation: Early detection of cardiac involvement and continuous monitoring of disease progression could benefit patients with light-chain amyloidosis. The application of left ventricular strain by Cardiac magnetic resonance feature tracking imaging has emerged as an excellent noninvasive imaging modality.

Goal(s): This study is dedicated to exploring the prognostic implications of myocardial strain in distinct myocardial segments.

Approach: The assessment of both global and segmental myocardial strain was conducted through the application of steady-state free precession (SSFP) cine sequences.

Results: Global radial strain (RS_global), RS in the basal lateral segment (RS_bas-lateral) and B-type natriuretic peptides (BNP) are independently associated with all-cause mortality.

Impact: Quantification of LV strain could be employed to monitor the progression of amyloid light-chain (AL) amyloidosis. Global radial strain and radial strain in the basal lateral segment may prove valuable for risk stratification in patients with AL amyloidosis.

Keywords: Heart Failure, Heart

Motivation: The challenge of obtaining high-quality CMR cine images in patients with heart failure (HF) due to difficulties in breath-holding and arrhythmia.

Goal(s): Explore the feasibility of utilizing compressed sensing cardiac cine with varying levels of acceleration to acquire comparable cine images in HF patients.

Approach: We compare cardiac function, strain parameters, and image quality between bSSFP and CS images in both HF patients and healthy participants, utilizing MRI systems from different vendors.

Results: Our findings demonstrate a high level of consistency in most cardiac function and strain parameters between the two  sequences. CS cardiac cine images exhibit comparable quality to bSSFP images.

Impact: This study offers prospective validation for the use of CS cardiac cine sequences in HF patients, addressing issues related to lengthy scanning durations and artifacts. It expands the eligible population for CMR scanning while optimizing image quality.

Keywords: Myocardium, Cardiovascular

Motivation: The association of preoperative LA strain assessed by cardiac magnetic resonance (CMR)-FT with the late outcome of HOCM patients after myectomy remains unknown.

Goal(s): To evaluate the prognostic value of preoperative LA strain in HOCM following myectomy.

Approach: In this retrospective, single-center study, 802 adult patients with HOCM after myectomy were included, who underwent preoperative CMR with clinical outcome follow-up.

Results: LA reservoir strain ≤ 22.9% was independently associated with postoperative adverse outcomes. Incorporating LA reservoir strain, the performance of the HCM Risk-SCD score improved for SCD prediction (C-statistic: from 0.62 to 0.69; log-likelihood: from -110.31 to -108.27, P=.04).

Impact: HOCM patients with reduced preoperative LA reservoir strain tend to have poor postoperative outcomes, so reinforced follow-ups may be required in those patients.

Keywords: Myocardium, Cardiomyopathy, Myocardial Strain; Hypertrophic cardiomyopathy(HCM); Mechanical function

Motivation: To identify potential imaging markers for early detection of hypertrophic cardiomyopathy (HCM) .

Goal(s): To evaluate mechanical dysfunction in HCM mice with different genotypes representing different disease stages.

Approach: Myocardial circumferential strain, radial strain, longitudinal strain, and torsion were assessed using two distinct strain assessment methods: feature tracking and tagging MRI.

Results: The results showed a significant reduction in myocardial strain in severe HCM, but an intriguing trend of slight elevation was observed before a decline in strain occurred in mild HCM, highlighting the potential value of these markers in the early detection of HCM.

Impact: Myocardial contractile function is significantly reduced in hypertrophic cardiomyopathy (HCM). However, our study suggests the presence of a compensatory phase during disease progression. Early identification of myocardial contraction dysfunction is vital for prompt detection and treatment, ultimately improving patient outcomes.

Keywords: Myocardium, Cardiovascular

Motivation: CMR left ventricular strain analysis is a crucial tool for assessing myocardial status, capable of identifying and evaluating regional myocardial dysfunction caused by coronary artery disease.

Goal(s): This study aims to evaluate the efficacy of cellular therapy in patients with chronic ischemic heart disease using left ventricular strain indices. 

Approach: 38 patients scheduled for coronary artery bypass grafting were randomly assigned to receive cellular therapy or serve as controls, followed by CMR imaging and strain analysis of various left ventricular views.

Results: Preliminary results indicate improvements in some CMR-derived strain indices in the cellular therapy group post-treatment, especially notable at 6 months post-operation.

Impact: This study provides new insights into the assessment of cellular therapy efficacy using CMR left ventricular strain indices, offering a more profound understanding and evaluation method for cellular therapy in patients with chronic ischemic heart disease.

Keywords: Myocardium, Cardiomyopathy, Dilated cardiomyopathy, Myocardial strain, Cardiac magnetic resonance imaging

Motivation: Dilated Cardiomyopathy (DCM) poses a significant clinical challenge due to its high mortality and limited cognitive understanding. Our motivation is rooted in enhancing diagnostic precision, unraveling novel insights into DCM pathology, and paving the way for targeted therapeutic interventions.

Goal(s): This study aims to unravel the intricate myocardial strain patterns in DCM patients through cardiac MRI techniques.

Approach: In this study, feature tracking method were used to evaluate myocardial strain.

Results: There is no significant difference in global left ventricular strain, variations emerge in segmental myocardial strain between genetic and secondary DCM patients. The myocardial strain rate exhibits disparities both globally and segmentally. 

Impact: This study unveils nuanced myocardial strain disparities in DCM, which could be utilized to illuminate diagnostic precision. The insights catalyze targeted therapeutic strategies, potentially revolutionizing care for DCM patients.

Keywords: Atherosclerosis, Cardiovascular, ST-segment elevation myocardial infarction; Left ventricular reverse remodeling; Cardiac magnetic resonance; Left atrial strain.

Motivation: Few studies have assessed the association of left atrial (LA) strain with left ventricular reverse remodeling (LVRR) after ST-segment elevation myocardial infarction (STEMI).

Goal(s): To investigate the potential utility of LA strain by using cardiac magnetic resonance feature-tracking (CMR-FT) to predict LVRR following STEMI.

Approach: The prospective study analyzed patients with a first STEMI and two CMR scans at 5 days and 4 months, and quantified LA strain by CMR-FT using cine images.

Results: LA reservoir and conduit strain, together with infarct size were independent predictors of LVRR.

Impact: The demonstrated predictive value of LA strain for the occurrence of LVRR after STEMI enables better assessment for the improvement of myocardial injury and guidance for the treatment in STEMI patients.

Keywords: Myocardium, High-Field MRI, Cardiac function, Strain

Motivation: To investigate whether a single set of shim values can provide reliable image quality for cardiac MRI at 7T.

Goal(s): To establish an efficient workflow for cardiac cine imaging at 7T.

Approach: Short-axis and long-axis views were acquired in five subjects with different spatial resolution at 3T and 7T. Volumetric parameters and peak global longitudinal and circumferential strain were assessed for left and right ventricle.

Results: No significant differences of volume parameters, field strength or spatial resolution were found. A single B1 shim set for the whole examination providing reliable image quality and quantification results constitute an essential step towards clinical cardiac imaging.

Impact: An efficient workflow and reliable image quality of cine images for the assessment of cardiac volumes and strain at 7 Tesla could be realized with results in close agreement to 3T – an essential step towards clinical routine cardiac examinations.

Keywords: Myocardium, Cardiomyopathy, Cardiac magnetic resonance, Left ventricular reverse remodeling, Left atrial strain

Motivation: The structure and function of left atrial (LA) have shown significant value in prognostic and risk stratification in dilated cardiomyopathy (DCM) patients. But no previous studies had reported its value for predicting left ventricular reverse remodeling (LVRR) in DCM.

Goal(s): This study aimed to explore whether fast long-axis strain (FLAS) of LA can provide predictive value. 

Approach: LA strain and other cardiac magnetic resonance (CMR) parameters were measured by CVI (version 5.13.7) in 96 patients. Statistical analysis was performed using SPSS.

Results: Both LACS and LGE were independent predictors of LVRR. The combination of LACS and LGE provided better prediction performance.

Impact: For the first time, our study demonstrated the predictive value of LA strain for LVRR. It would be beneficial for DCM patients who were contradictive to contrast agencies.

Keywords: Myocardium, Cardiomyopathy

Motivation: Early prediction of LVr is significant for the selection of clinical treatment to improve the prognosis of STEMI patients.

Goal(s): To explore whether strain markers, as derived by CMR feature tracking (CMR-FT) at the early onset of STEMI may improve the predictive certainty of LVr.

Approach: 120 patients with a first reperfused STEMI were investigated prospectively within 7 days after PCI. Both LA and LV strain and strain rate were calculated using CMR-FT.

Results: The reduction of LV-GLS can predict LVr independent of T2* value, and the reduction of LA-ℇe remain an independent predictor of LVr after adjusting LV-GLS and T2* value.

Impact: In the present study, the reduction of LA conduit strain derived by CMR-FT at the early onset of STEMI increases the likelihood of LVr independent of T2* value and LV-GLS.

Keywords: Myocardium, Cardiovascular

Motivation: Hyperuricemia and abnormal ω-6/ω-3 values contribute to cardiac damage, but the specific mechanisms remain unclear.

Goal(s): To explore the effects of uric acid and ω-6/ω-3 values on left heart function using cardiac magnetic resonance feature tracking.

Approach: We utilized the TrueFISP cine sequence, CVI42 software, and univariate and multivariate linear regression analyses to identify relationships of uric acid and ω-6/ω-3 values with left heart function.

Results:  High ω6/ω3 values may exacerbate left ventricular dysfunction in patients with hyperuricemia.

Impact: Our findings concerning the effects of uric acid and ω-6/ω-3 values on left heart function will help to improve the clinical management and treatment of patients with hyperuricemia.

Keywords: Heart Failure, Myocardium, cardiac MRI; exertional heat illness; myocardial strain; return-to-play

Motivation: More attention has been paid to the diagnosis and treatment of patients with heatstroke, while little research has been done on its prognosis. 

Goal(s): The main hypothesis is that left ventricle strain parameters assessed by CMR feature tracking can predict long-term heart symptoms in exertional heatstroke patients.

Approach: Patients with exertional heatstroke underwent serologic cardiac enzyme levels and CMR at baseline and follow-up to assess the relationship between left ventricular strain parameters and recovery training.

Results: The 2D-global longitudinal strain provided incremental prognostic value over traditional outcome predictors (areas under the receiver operating characteristic curve comparing models, 0.788 vs 0.883; P = 0.023).

Impact: Our findings suggest that ongoing reduction in left ventricle strain may explain the lingering cardiac symptoms in patients with previous heat illness.  It will help identify individuals at risk, improve follow-up, and provide assistance for return-to-play and reducing future risks.

Keywords: Myocardium, Cardiovascular

Motivation: People living with HIV are at increased risk of cardiovascular disease compared with healthy people.

Goal(s): To explore the extent of diastolic atrial and left ventricular dysfunction in PLWH by CMR in correlation with clinical markers of disease activity.

Approach: 101 PLWH and 62 healthy volunteers were recruited for this study in China. Both left atrial (LA) and LV strain and strain rate were calculated using CMR feature tracking.

Results: PLWH had a larger LAVImax, LAVImin and LAVIpre-a as compared to healthy volunteers. The LA
reservoir, conduit and booster pump function were all impaired in PLWH.

Impact: The prevalence of diastolic dysfunction as well as asymptomatic systolicabnormalities is observed in HIV patients.

Keywords: fMRI Analysis, Myocardium, acute myocarditis;feature tracking; LA strain

Motivation: The prognostic significance of left atrial strain (LA) in acute myocarditis (AM) remains unknown. 

Goal(s): This study aimed to conduct a quantitative evaluation of the LA function in AM patients and explore whether LA strain parameters can predict the outcomes of AM patients.

Approach: LA strain was assessed by using cardiovascular magnetic resonance feature tracking (CMR-FT) in this study.

Results: LA strain parameters were significantly impaired in AM patients with major adverse cardiovascular events (MACEs) and reservoir LA longitudinal strain was found to be an independent predictor of MACEs, with a hazard ratio per 1% increase of 0.954 (P<0.05).

Impact: LA reservoir strain may serve as a useful tool to predict the adverse prognosis of AM and have the potential to guide the distant therapy of patients with acute myocarditis.

Keywords: Myocardium, Cardiovascular

Motivation: To explore the application value of cardiac magnetic resonance (CMR) feature tracking technique in patients on maintenance hemodialysis(MHD).

Goal(s): To explore the application value of CMR feature tracking technique in patients on MHD.

Approach: CMR examination was performed in both groups, and the left ventricular myocardial strain values were obtained by FT-CMR to explore the differences in myocardial deformation between the two groups.

Results: With the increase of dialysis age, GCS, GRS and GLS were significantly lower than that in the low dialysis age group (-24.97±8.63 vs. -19.11±6.18, P=0.017; 23.31±9.96 vs. 33.23±15.88, P=0.022; -18.26±3.19 vs. -22.96±6.72, P=0.008).

Impact: In those with preserved ejection fraction, myocardial strain parameters are reduced, suggesting that the use of FT-CMR technique is helpful for early diagnosis of myocardial deformation injury in MHD patients.

Keywords: Atherosclerosis, Heart

Motivation: Compared with primary percutaneous coronary intervention (PPCI), it is not known whether patients with ST-elevation myocardial infarction (STEMI) benefit from thrombolysis prior to PCI within 120 minutes of symptom onset.

Goal(s): This study was to compare the short-term performance between STEMI patients with and without a single bolus recombinant staphylokinase (r-SAK) prior to PCI by Cardiac Magnetic Resonance (CMR) imaging.

Approach: The global and segmental [mainly focusing on LGE+ segment (transmural extent >50%)] CMR parameters were compared between r-SAK group and control group. 

Results: Patients can benefit from thrombolysis prior to PCI with better myocardial function and smaller extent of edema.

Impact: This study investigated the short-term advantages of adjunctive thrombolysis with r-SAK for STEMI patients undergoing PCI. A single bolus r-SAK intravenously prior to PCI for STEMI improves myocardial function and reduces the extent of edema.

Keywords: Myocardium, Myocardium, myocardial delayed enhancement, deep learning reconstruction

Motivation: Myocardial delayed enhanced (MDE) imaging is the gold standard for assessing myocardial viability in various cardiac pathologies. However, long breath-hold is needed for MDE to achieve reasonable spatial resolution, hampering its utility for patients with insufficient breath-hold capability.

Goal(s): The goal for this study is to optimize a variable-density undersampling pattern to achieve highly accelerated MDE imaging combined with deep learning reconstruction. 

Approach: The optimization was conducted with phantom and post-contrast in vivo studies.

Results: The optimized undersampling pattern and deep learning reconstruction enable 4-time acceleration for phase-sensitive MDE imaging with comparable image quality to the reference image.

Impact: The optimized variable-density undersampling pattern combined with deep learning reconstruction can potentially expand the clinical utility of MDE imaging to especially patient with insufficient breath-hold capability, and improve the patient comfort.

Keywords: Machine Learning/Artificial Intelligence, Cardiovascular, Scan planning, Cardiovascular MR acquisition, Computational geometry

Motivation: Manual planning for cardiac MRI (CMR) involving complex oblique views is time-consuming and introduces intra- and inter-technologist variability.

Goal(s): To develop a fast and robust model that automatically predicts the standard CMR views from a 3D survey scan (SS) image. 

Approach: We use a deep learning (DL) based approach to map the 3D-SS image to four standard CMR using an instance segmentation strategy that identifies all planes followed by a finetuning strategy, which potentially offers improved robustness.  

Results: We achieved mean angulation and offset errors of 3.72±2.1 degrees and 2.36±1.8 mm, respectively across four standard CMR views averaged across 100 test subjects.

Impact: Plane estimation as instance segmentation problem understands the spatial conformations of the planes and can adapt to various heart shapes and sizes and can go a long way in reducing intra- and inter-technologist variability and more importantly reducing scanning time.

Keywords: Flow, Cardiovascular, Exercise, diastolic function

Motivation: Exercise testing is important in evaluation of diastolic dysfunction but there is little use of exercise for diagnosis.

Goal(s): Test if MR phase-contrast and cine techniques can identify changes in E, A, and e’ with hand-grip exercise.

Approach: Five healthy subjects underwent diastolic function evaluation by MRI, during isometric handgrip exercise.  E, A and e’ were evaluated.

Results: In this group, E/A decreased with exercise, and recovered after a period of rest. Isometric handgrip exercise is promising approach for revealing diastolic dysfunction in patients.

Impact: Isometric hand-grip exercise may be a useful tool in exercise cardiac MRI  for diagnosis in patients with heart failure with preserved ejection fraction.

Keywords: Myocardium, Cardiovascular, SWIN, ESPIRiT, Resnet, CINE

Motivation: Cardiac CINE MRI is used clinically for characterizing heart morphology and function, but requires multiple breath-holds to minimize motion artifacts from respiration.

Goal(s): Deep learning based ESPIRiT (DL-ESPIRiT) is able to reconstruct dynamic MRI data with high reconstruction accuracy. However, the method still has difficulty resolving fine anatomic structures. We aim to improve reconstruction accuracy using newer transformer architecture.

Approach: We replace the ResNet deep learning backbone by a modified Swin Image Restoration network (SwinIR) with video Swin transformers, called DL-ESPIRiT VSwinIR

Results: DL-ESPIRiT VSwinIR has substantially improved reconstruction accuracy and can accelerate acquisitions by up to 20x.

Impact: Fast CINE acquisitions using our DL-ESPIRiT VSwinIR may enable multiple CINE slices to be acquired in a  shortened breath-hold, which will allow heart morphology and function assessment in patients with difficulty breath-holding or following instructions.

Keywords: Myocardium, Cardiovascular, 3D real-time imaging

Motivation: To achieve high-temporal-resolution 3D whole-heart MR cine without the need for ECG, allow direct visualization of physiological motions, and assess cardiac function in clinical practice.

Goal(s): To attain 3D multi-slice whole-heart real-time imaging with <50 ms temporal resolution, while preserving adequate spatial resolution for cardiac functional analysis.

Approach: We employed golden-angle rotated spiral-in/out trajectory with 32× acceleration, and randomized variable density k_z phase-encoding in the bSSFP sequence, and harnessed an iterative reconstruction algorithm.

Results: We attained a groundbreaking achievement in advancing MRI capabilities, obtaining an ECG-free 3D real-time cardiac cine with complete 12-slice whole-heart coverage and an impressive sub-50 ms temporal resolution.

Impact: We've employed advanced techniques to triumph over MRI's historical disadvantage of slower acquisition compared to other modalities. Pioneering a groundbreaking approach, we achieve high temporal resolution for 3D real-time imaging without ECG, breath-holding, or data segmentation, revolutionizing cardiac motion capture.

Keywords: Myocardium, Data Acquisition

Motivation: Cine imaging is important for CMR quantification of left ventricular (LV) function, but conventional breath-held techniques are time consuming. 

Goal(s): This study aims to improve continuous spiral-based cardiac cine acquisition efficiency.

Approach: A CAIPIRINHA-based SMS imaging using spiral acquisition with respiratory correction and cardiac self-gating strategy is proposed.

Results: By optimizing the phase modulation pattern with robust self-gating signal extraction, cine images covering the whole LV are obtained in approximately 30s free breathing without ECG gating. The proposed technique yielded comparable LVEF to the clinical gold-standard. Although image quality was slightly inferior to the clinical technique, SMS-SPARCS produced diagnostically acceptable image quality.

Impact: This study furthers our insight into designing phase modulation and reconstruction techniques for continuous spiral-based multi-slice self-gated acquisition. This technique improves efficiency of cine acquisition and does not require ECG or breath-holding.

Keywords: Myocardium, Myocardium, pulmonary hypertension; mechanical dyssynchrony;

Motivation: The ability of layer-specific intraventricular mechanical dyssynchrony (M-dys) to predict prognosis in pulmonary arterial hypertension (PAH) has not been investigated.

Goal(s): To illustrate the existence and prognostic values of layer-specific intraventricular M-dys and its associations with electronical dyssynchrony in PAH.

Approach: The biventricular volumetric and layer-specific intraventricular M-dys were analyzed by calculating strain and strain rate based on cine cardiac magnetic resonance images.

Results: The layer-specific intraventricular M-dys had varying impacts on biventricular functions in PAH.

Impact: This study was novel in reporting that the layer-specific intraventricular M-dys had various distribution patterns in both ventricles in patients with PAH.

Keywords: Myocardium, Cardiovascular, Ventricular remodeling· Magnetic resonance imaging· ST elevation myocardial infarction· Left atrial reservoir strain rate

Motivation: Understanding reverse left ventricular remodeling (r-LVR) after ST-segment elevation myocardial infarction (STEMI) is important for patients. It is unknown whether left atrium (LA) volume and function can predict r-LVR.

Goal(s): The aim of study was to evaluate the changes in left heart structure and function by performing two cardiac magnetic resonance (CMR) scans and then to explore the value of LA in predicting r-LVR.

Approach: A total of 105 STEMI patients were studied. The predictors of r-LVR were analyzed by logistic regression method.

Results: LV end diastolic volume (LVEDV), total enhanced mass and LA reservoir strain rate were significantly predictors of r-LVR.

Impact: Our study described the natural course of the left heart over time in patients with STEMI, evaluated predictors of left heart for r-LVR, and found that LA reservoir strain rate and LV longitudinal displacement had similar value for predicting r-LVR.

Keywords: Myocardium, Cardiovascular

Motivation: Deep-learning image reconstruction is promising for improving image quality and may enable higher acceleration for cardiac CINE MR.

Goal(s): To investigate deep-learning-based image reconstruction for accelerating cardiac CINE MRI over compressed sensing (CS) reconstructions without affecting quantitative measures of ejection fraction.

Approach: Cardiac CINE MR with CS factors 2-5 were acquired in 15 volunteers and reconstructed with one standard and two AI methods. Ejection fractions were calculated, and a subset of images were graded for image quality.

Results: CS-factors did not materially affect ejection fractions (left-ventricle p=0.969, right-ventricle p=0.998). Blurring (p<0.01) and perceived SNR (p<0.01) were improved by AI reconstruction at high acceleration.

Impact: Deep learning MR reconstruction reduces penalties from high acceleration in cardiac MRI CINE imaging, allowing for shorter breath-holds, shorter exams, non-compromised image quality, and preserved quantitative measurements.

Keywords: Myocardium, Cardiomyopathy

Motivation: CMR, the gold standard for diagnosing myocardial diseases, is known for its ability to assess local myocardial fibrosis through LGE imaging. However, this imaging technique requires a contrast agent, limiting its use in patients with allergies or renal dysfunction.

Goal(s): The purpose of this study is to assess the ability of MVs/MVd as a new indicator to measure the extent of myocardial fibrosis.

Approach: Explore the correlation between MVs/MVd and LGE% in patients with hypertrophic cardiomyopathy.

Results: The results indicate that MVs/MVd may possess the ability to indicate myocardial fibrosis without the need for a contrast agent.

Impact: MVs/MVd, in contrast to traditional methods, directly measures the entire cardiac cycle, offering valuable insights into myocardial properties. Importantly, it can gauge myocardial fibrosis to some extent without requiring a contrast agent, making it clinically significant for diagnosis and treatment.

Keywords: Heart Failure, Cardiovascular

Motivation: To investigate the potential of different CMR parameters as non-invasive, indirect indicators of NT-proBNP levels in HEpEF patients and to assess their utility in enhancing disease prognosis and assessment.

Goal(s): The objective of this study is to explore the relationship between NT-proBNP and left ventricular functional parameters, T1 mapping, ECV, and myocardial strain parameters in CMR.

Approach: A retrospective study was conducted with a cohort of HEpEF patients. Advanced cardiac MRI techniques were utilized to ascertain each CMR parameter.

Results: A notable correlation was discerned between myocardial stress parameters and Native T1 values with serum NT-proBNP levels.

Impact: NT-proBNP is a fundamental biomarker for assessing and predicting alterations in left ventricular function. Myocardial stress parameters and Native T1 showcase potential as non-invasive indicators.Future research must focus on multi-center, prospective studies to validate and expand on these findings.

Keywords: Myocardium, Cardiovascular

Motivation: The two-dimensional (2D) cine balanced steady-state free precession (SSFP) sequence requires multiple breath-holds for cardiac imaging. A three-dimensional (3D) cine Enhanced sensitivity encoding (SENSE) by Static Outer-volume Subtraction (ESSOS) sequence was introduced to reduce the acquisition time.

Goal(s): To explore the diagnostic value of the 3D cine sequence in patients with hypertrophic cardiomyopathy (HCM).

Approach: All patients with HCM were scanned for cine imaging using conventional 2D SSFP and 3D ESSOS sequences. Cardiac structure and function parameters measured by 3D cine and 2D cine were compared.

Results: The 3D cine can rapidly obtain cardiac parameters with good diagnostic accuracy in patients with HCM.

Impact: The 3D ESSOS cine has good diagnostic accuracy for HCM. This sequence can acquire whole-heart images in a single breath hold, greatly improving efficiency and reducing patient discomfort. It should be used to screen people at high risk for HCM.

Keywords: Myocardium, Brain, cardiac function

Motivation: Impaired cardiac function has been associated with cognitive deterioration. However, the correlation of cardiovascular function to cerebral structures remains unclear. 

Goal(s): We studied whether the ventricular function is associated with measures of subcortical volumes in a general patient population. 

Approach: All participants were imaged using a 3T MRI systems. Cardiac 2D SSFP CINE was acquired for cardiac function. Brain structural images were acquired using a 3D MPRAGE.

Results: Among seven subcortical structures examined in 101 healthy adults, only the thalamic volume demonstrated a positive association with left ventricular stroke volume and right ventricular end diastolic volume.

Impact: In healthy adults, the thalamic volume demonstrated a positive association with left and right ventricular stroke volume. 

Keywords: Vascular, Blood vessels

Motivation: The prognosis of advanced pulmonary hypertension (PH) is poor, and incorrect treatment methods may accelerate this process.

Goal(s): To comprehensively investigate the characteristics of PH by employing various imaging sequences, including 4D Flow, cardiac cine, T1/T2mapping. 

Approach:  CMR imaging was performed on different cardiac index (CI) of PH patients and healthy volunteers to calculate various parameters of the heart and pulmonary arteries. Wilcoxon rank test was used to evaluate inter group differences.

Results: A multi-sequence MRI approach effectively detects and characterizes abnormal heart and pulmonary artery features in PH of different CI, offering insights for early diagnosis and clinical management.

Impact: The research has provided initial insights into the cardiac characteristics of high-CI and low-CI PH patients using magnetic resonance imaging (MRI) technology. It offers new data and perspectives to better understand the physiological and pathological changes in these patients.

Keywords: Vessels, Heart, NMR spectroscopy

Motivation: Heart valve disease (HVD) is a multifactorial process and its pathophysiology has not been fully understood. 

Goal(s): To investigate and determine the metabolite tissue using the ¹H-NMR based metabolomics study to discriminate the aortic valve and mitral valve. 

Approach: proton NMR spectroscopy 

Results: The results obtained from PLS-DA and VIP score plots of metabolites in tissue showed a separation between patients with aortic valves and mitral valves.

Impact: The present study revealed discrimination of metabolic profiling of tissue of aortic valve patients from mitral valve replacement implying that 1H-NMR-based metabolomics may provide an insight into understanding the potential metabolic alteration. 

Keywords: Myocardium, Cardiomyopathy

Motivation: Alterations in cardiac metabolism are implicated in numerous heart diseases, including cardiomyopathies, heart failure, and ischemic disease. Patients with hypertrophic cardiomyopathy (HCM) have known dysregulation of cardiac metabolism and energetics, and studies group aim to provide non-invasive measurements of dysregulation to allow for earlier diagnoses as well as monitoring of treatments.

Goal(s): In this project, we aim to translate HP 13C-MRI into human studies of cardiac metabolism.

Approach: This project will include studies of healthy subjects for normative values as well patients with HCM.

Results: Preliminary results show clear abnormalities in metabolic imaging but no one metabolic phenotype across all five HCM patients

Impact: In this project, we aim to translate HP 13C-MRI into human studies of cardiac metabolism. Alterations in cardiac metabolism are implicated in numerous heart diseases, including cardiomyopathies, heart failure, and ischemic disease.

Keywords: Heart Failure, Cardiomyopathy

Motivation:  ^31­P heart applications can be used to monitor cardiac energetics, treatment response in vivo and metabolic inflexibility, a key feature of the failing heart.

Goal(s): We present here a 7T and 3T protocol for  ^31­P heart application, including the validation of a dipole array coil design.

Approach: We evaluated the performance of the coil at 7T with B₁ maps and through in vivo scans of 8 healthy with a long ³¹P CSI protocol, and tested the 3T protocol on 5.

Results: Results show spectra of excellent quality. PCr/gATP ratios lie within the expected range and B1+ maps show good uniformity. 

Impact: This coil design has the potential of lifting the current limitations associated with the wider use of   ^31­P cardiac MRSI to study the heart energetics. It can also help the diagnosis and the design of new drugs in the future. 

Keywords: Heart Failure, Spectroscopy, Cardiac 31P-MRS, Iron deficiency

Motivation: Determining the impact of iron repletion on muscle energetics in non-ischaemic cardiomyopathy with reduced ejection fraction (EF).

Goal(s): Use cardiac and skeletal muscle 31P MRS to assess cardiac and skeletal muscle energetics pre and post iron repletion therapy.

Approach: Participants and ID underwent CMR to assess cardiac function, MRS to assess Phosphocreatine to Adenosine triphosphate (PCr/ATP) ratio in cardiomyocyte and relation to skeletal muscle PCr consumption, end-exercise intracellular pH and PCr recovery rate before and after Ferric carboxymaltose (FCM).

Results: FCM improves ejection fraction, 6-minute-walk-distance. It didn’t change in myocardial resting or dynamic energetics or skeletal muscle oxidative metabolism.

Impact: Iron infusion didn’t change PCr/ATP, however increased left ventricular ejection fraction,  therefor increase ATP requirement. We hypothesise that iron replacement resulted in increase in energy efficiency, or improved flux through Creatine Kinase, which was not assessed during this study. 

Keywords: Heart Failure, Oxygenation, Quantitative Susceptibility Mapping (QSM), Venography, Cardiorespiratory fitness, Cognition

Motivation: There is a lack of knowledge about the physiological underpinnings of the effects of coronary artery disease (CAD) on human brain health.

Goal(s): Here we investigated the effect of CAD on brain oxygen extraction fraction (OEF) 

Approach: Using quantitative susceptibility mapping (QSM) and its relation to cognitive performance and cardiorespiratory fitness.

Results: The results of the sex-disaggregated analysis in a preliminary dataset show that CAD male patients have significantly higher OEF in whole gray matter, frontal, occipital, and temporal lobes. Furthermore, higher OEF in males is associated with lower  cognitive performance, and higher OEF is associated with lower VO2max.

Impact: Sex differences in the effects of coronary artery disease (CAD) on brain health are unknown. Our results show that CAD increases OEF, and that higher OEF is associated with lower cognitive performance , and lower cardiorespiratory fitness in males.

Keywords: Myocardium, Cardiovascular, Quantitative Susceptibility Mapping (QSM); Myocardial Blood Volume(MBV)

Motivation: Myocardial Blood Volume (MBV) is an important factor in the progression of cardiac pathologies.

Goal(s): We proposed to combine a motion-resolved cardiac high-dynamic-range quantitative susceptibility mapping (HDR-QSM) approach with ferumoxytol (an iron-based intravascular contrast agent) to accurately measure myocardial blood volume (MBV).

Approach: HDR-QSM was prescribed in pigs with and without AMI after ferumoxytol administration to investigate the cyclic MBV changes and infarct-induced MBV redistribution in AMI.

Results: Significant MBV difference was observed between systolic and diastolic phases between healthy and infarcted hearts. 

Impact: Ferumoxytol-enhanced cardiac QSM has the potential to accurately quantify motion resolved MBV in healthy and diseased hearts.

Keywords: Heart Failure, Cardiovascular

Motivation: Right ventricular (RV) failure in pulmonary arterial hypertension (PAH) increases mortality risk, yet its metabolic characteristics is largely unknown, primarily due to limitations of imaging the RV.

Goal(s): This study examines the relative contribution of oxidative metabolism versus glycolysis in the failing RV before and after initiation of pulmonary vasodilator therapy for PAH.

Approach: Patients with newly diagnosed PAH are examined by HP [1-¹³C]pyruvate MRI at baseline and again 4-6 months after initiation of pulmonary vasodilator therapy.

Results: Patients exhibited hyperintense HP bicarbonate signals in RV free wall. After treatment, normalized myocardial [¹³C]bicarbonate production increased.

Impact: Importance of metabolic flexibility in RV heart failure is underexplored. A better understanding of how the RV myocardium remodels in RV failure from PAH and in response to therapy may allow for development of RV-targeted therapies to maintain RV function.

Keywords: Myocardium, Contrast Agent, manganese-enhanced MRI

Motivation: Manganese-enhanced MRI (MEMRI) appears to be an interesting alternative to late-gadolinium enhancement (LGE) since manganese ions can enter cardiomyocytes through calcium channels, thus allowing intracellular characterization of living cells.

Goal(s): This study aims to evaluate the sensitivity of 3D-MEMRI for the characterizing MI scars heterogeneity compared to the clinical gold standard LGE.

Approach: Manganese has a long retention time in cardiomyocytes, allowing a longer acquisition time exploited to improve the spatial resolution of 3D MR images (~1 mm³ isotropic).

Results: This study confirms the potential of 3D-MEMRI as a more specific method than the clinical gold standard LGE for characterizing MI scars heterogeneity.

Impact: The ability of high-resolution 3D manganese-enhanced MRI (3D-MEMRI) to produce a finer characterization of the heterogeneity of the scar constitutes an important step forward in the management of myocardial infarction in the context of cardiac arrhythmias

Keywords: Vascular, Vessels, MRA

Motivation: Visualizing vascular calcifications is crucial for atherosclerosis assessment, guiding interventions, and predicting risks. Existing MRI techniques fall short in this regard, necessitating additional time-consuming scans or resorting to CTA.

Goal(s): To develop a new non-contrast, single-scan solution to simultaneously acquire MR angiography (MRA) and calcification-weighted images (CWI).

Approach: We redesigned and extended the existing Relaxation-Enhanced Angiography without ContrasT (REACT) framework with different pre-pulses, termed REACT-MIX. Volunteers were used for feasibility testing, comparisons with existing techniques, and subsequent patient evaluations to assess vascular lesions.

Results: Initial findings indicated good feasibility of simultaneous MRA and CWI, encouraging further clinical evaluation.

Impact: REACT-MIX introduces a new approach enabling simultaneous non-contrast MR angiography and calcification-weighted imaging across a wide FOV in a single scan. It offers promise for clinical assessments of systemic atherosclerosis. Further studies are warranted to confirm its full potential.

Keywords: Myocardium, Machine Learning/Artificial Intelligence

Motivation: Exploring metabolic markers for detecting cardiac remodeling (CR) in athletes to differentiate adaptive from harmful changes.

Goal(s): To use ¹H-MRS for identifying metabolites predictive of CR in athletes.

Approach: Recruitment of male athletes and controls for CMR examination, analysis of myocardial metabolites using ¹H-MRS, and application of machine learning algorithms to construct predictive models for CR.

Results: Discovery of a correlation between increased myocardial creatine levels and lipid ratios in athletes with CR, with ¹H-MRS proving effective in predicting CR, highlighting MYCL-CH3/W as a particularly predictive metabolite, and positioning the KNN algorithm as a robust predictive tool.

Impact: The study advanced sports cardiology by identifying myocardial metabolites as noninvasive markers for differentiating between healthy and adverse cardiac remodeling in athletes, enhancing training strategies and early detection of cardiac risk.

Keywords: Myocardium, Non-Proton, sodium, X-nuclei, chronic kidney disease, hemodialysis, cardiomyopathy

Motivation: Cardiovascular risk is elevated in chronic kidney disease (CKD) patients on hemodialysis (HD) and may be associated with tissue sodium accumulation in the heart.

Goal(s): To compare tissue sodium concentration (TSC) in the interventricular septum of HD patients and healthy controls using sodium (²³Na) MRI.

Approach: ²³Na MRI was performed on 3 HD patients and 6 controls to quantify TSC in the interventricular septum.

Results: TSC in the septum was higher in HD patients compared to controls but was not statistically significant. These results may be limited by sample size and age and sex effects, which will be explored in a larger cohort.

Impact: For the first time, ²³Na MRI was used to directly measure TSC in the heart of CKD patients on HD. These findings may provide insight on the cardiovascular risk associated with sodium accumulation in this group.

Keywords: Myocardium, Spectroscopy, MRS, Phosphorus

Motivation: In cardiac ³¹P-CSI MRS, the signals containing ³¹P are important markers of myocardial health. Optimizing metabolite quantification is essential for understanding myocardial bioenergetics and related pathologies. 

Goal(s): The aim was to quantify an extended range of low-signal metabolites including PME, Pi, GPE, GPC, PEP, and NAD.

Approach: 36 of the existing ³¹P-CSI MRS volunteer data at 7T were analysed using an optimized and extended prior knowledge. 

Results: The results, presented as chemical shift, line-width, amplitude, and their CRBs, demonstrated successful quantification of low-signal metabolites alongside with 2,3-DPG, PCr, and ATP in the same spectra, demonstrating the feasibility of quantifying these signals at 7T. 
 

Impact: The 7T cardiac ³¹P-CSI MRS data provide valuable insight and demonstrates that low-signal metabolite quantification is possible. Looking at these signals in patient data may add to cardiac ³¹P MRS and could provide new markers of myocardial health.

Keywords: Myocardium, Spectroscopy, RF Coils, Metabolism

Motivation: Cardiac ³¹P MRS is limited by the low sensitivity of commonly used transmit-receive surface coils at larger distances from the coil. Therefore, with transmit-receive surface coils, data is often acquired in prone position, which brings the heart closer to the coil.

Goal(s): Determine the sensitivity of cardiac 3D ³¹P MRSI in prone and supine positions using an integrated ³¹P whole-body birdcage transmit coil at 7T.

Approach: A male and female subject were scanned in prone and supine position.

Results: 3D ³¹P MRSI data were obtained with good sensitivity throughout the whole heart, regardless of the position of the subject.

Impact: With an integrated ³¹P whole-body transmit coil at 7T, cardiac ³¹P MRS can be performed in the more comfortable supine position, with good sensitivity also in the posterior cardiac wall.

Keywords: Atherosclerosis, Kidney, chronic kidney disease, zero echo time, deep learning

Motivation: Screening opportunity might increase detection of calcium presence in cardiac tissues. Calcium deposit in cardiac tissues especially vessels alter flow hemodynamics. A non-invasive zero echo time magnetic resonance imaging (ZTE-MRI) may offer additional information when patients receive routine cardiac magnetic resonance imaging (CMR).

Goal(s): To propose a three-minute, high-resolution, high-SNR free-breathing ZTE-MRI in detection of coronary artery calcification.

Approach: To subjectively and objectively evaluation of ZTE-MRI respectively using conventional and deep learning reconstruction using CT as reference.

Results: DLR ZTE-MRI had superior image quality to noDLR ZTE-MRI and showed fair to good performance on calcium deposit by visual observation.  

Impact: DLR ZTE-MRI with the featurs of fee-radiation, silence, and comfort (free-breathing) during scan can provide extra information – calcium deposite, for whoever, especially a CKD patient, plans to receive a physical examination especially CMR examinaition.

Keywords: Flow, Heart, Heart failure, ejection fraction, radiomics

Motivation: HFpEF (heart failure with preserved ejection fraction) patients show similar diagnostic parameter values to healthy subjects in the quantitative evaluation of cardiac magnetic resonance imaging (CMR). Improving the performance of CMR-based HF characterization is desirable.

Goal(s): Evaluation of radiomics features from 2D flow MRI of the aorta for the classification into healthy, HFpEF, HFmrEF (mildly reduced) and HFrEF (reduced).

Approach: Training and evaluation of a decision tree classifier using 70 CMR datasets with conventional diagnostic parameters and 2D flow radiomics features to find relevant flow descriptors.

Results: The classifier achieved excellent results, considering the local flow homogeneity during diastole.

Impact: We evaluate adding 2D flow MRI radiomics to standard EF measurements for the classification of heart failure subtypes. This would enable the diagnosis of the subtypes with one imaging modality without the need for stress testing. 

Keywords: Heart Failure, Diabetes, global longitudinal strain; heart failure with preserved ejection fraction; diabetes mellitus; prognosis

Motivation: While diabetes mellitus has a high prevalence in HFpEF and being associated with poorer outcomes, limited data are available on the cardiac MRI features of diabetic HFpEF

Goal(s): We aimed to explore imaging features including tissue characterization and myocardial deformation in diabetic HFpEF patients by MRI, and investigate its prognostic value for adverse outcomes

Approach: Feature-tracking derived strain and strain rates parameters and myocardial fibrosis were assessed by cardiac MRI in patients with diabetic HFpEF

Results: Diabetic HFpEF patients were characterized by more impaired strains and myocardial fibrosis. Tissue characterization and global longitudinal strain obtained from MRI-FT provided incremental value for risk prediction

Impact: Our findings suggested that MRI-derived variables especially GLS played a crucial role in risk stratification and predicting worse prognosis in diabetic HFpEF, which could assist in identifying high-risk patients and guide therapeutic decision making.

Keywords: Myocardium, Cardiovascular, SSc primary heart involvement, cardiovascular magnetic resonance,extracellular-volume fraction, modified Rodnan skin score

Motivation: Cardiac involvement is a significant cause of mortality in SSc. There are, however, no effective methods for detecting cardiac involvement in a general, asymptomatic SSc cohort.

Goal(s): We aimed to characterize and identify subclinical SSc-pHI by CMR.

Approach: 48 Patients underwent CMR, including cine imaging, LGE, T2 mapping, and native and post-contrast T1 mapping for ECV quantification.

Results: 56.25% of SSc-pHI patients had LGE, and 79.16% and 54.17% had native T1 and ECV above normal values. In addition, patients with dcSSc had worse contractility than patients with lcSSc, and contractile function is closely related to presence of RP, dcSSc, and ANA positive.

Impact: Cardiac magnetic resonance imaging provides a reliable method for detecting sub-clinical cardiac involvement in SSC patients. Patients with dcSSc had worse contractility than patients with lcSSc, and contractile function is closely related to presence of RP, dcSSc, and ANA positive.

Keywords: Myocardium, Cardiovascular

Motivation: Cardiopulmonary circulation usually present hemodynamic congestion in RCM patients. Pulmonary transit time (PTT) and pulmonary blood volume index (PBVi) are physiological parameters reflective of cardiopulmonary hemodynamics statue.

Goal(s): Evaluate the PTT and PBVi in RCM patients, and evaluated the association with LV function and deformation.

Approach: The images of first-pass perfusion were acquired to assess PTT which was normalized to heart rate. PBVi was measured by the product of PTT and RVSV and indexed to BSA.

Results: PTT showed independent association with LVEF and LVMVR, as well as with LV GCPS and GLPS; PBVi was an independent association of LVMI and LV GRPS.

Impact: PTTc and PBVi as the non-invasive marker of cardiopulmonary hemodynamics in patients with RCM, and reflects progression of diastolic dysfunction, and impaired LV global deformation. PTT and PBVI may provide additional information for prognostic management and clinical decision making.

Keywords: Heart Failure, Perfusion, Heart failure, preclinical imaging, HFpEF animal model, MRI

Motivation: Addressing the challenges in heart failure with preserved ejection fraction (HFpEF) diagnosis, the study aimed to validate cine-ASL as a precise non-invasive imaging tool.

Goal(s): The study sought to explore nuanced aspects of HFpEF, enabling a better understanding of its complexities through advanced imaging techniques.

Approach: Employing advanced cardiac magnetic resonance imaging with arterial spin labeling (cine-ASL), our study investigates longitudinally myocardial perfusion in a two-hit mouse HFpEF model.

Results: Significant reductions in myocardial perfusion in a HFpEF-like mouse model revealed the technique's efficacy in capturing HFpEF-related changes.

Impact: These findings highlight early coronary microcirculation impairment in HFpEF-like myocardium, shedding light on potential diagnostic biomarkers for HFpEF and paving the way for improved early diagnosis and understanding of the HFpEF pathophysiology.

Keywords: Heart Failure, Dementia, Myocardial strains

Motivation: The mechanism of heart failure()-induced brain alterations is unclear

Goal(s): To investigate the alterations in brain structure in patients with HF and their relationship with cardiac dysfunction and cognitive impairment.

Approach: Using CAT12 to analyze intergroup differences in cortical thickness between HF patients and healthy controls, correlation analyses were performed to assess cortical thickness and cognitive impairment, cardiac dysfunction

Results: Reduced cortical thickness in patients with HF and correlation of reduced cortical thickness with cognitive impairment and cardiac dysfunction

Impact: Decreased cortical thickness in HF patients may play a mediating role between cardiac dysfunction and cogntive impairment.And our findings provide imaging evidence of brain alterations in HF patients.

Keywords: Heart Failure, Heart

Motivation: Heart failure with preserved ejection fraction (HFpEF) frequently presents with atrial fibrillation (AF). But the mechanism of AF in HFpEF are incompletely understood. Epicardial adipose tissue (EAT) is linked with left atrial volume and function changes.

Goal(s): This study aims to evaluate the relationships between EAT volumes and AF in patients with HFpEF.

Approach: All subjects were imaged with a 3.0T Philips scanner. CMR parameters were quantified with a stack of short axis views perpendicular to the long axis of the left ventricle.

Results: EAT was an independent predictor for the presence of AF in patients with HFpEF and demonstrated high prediction power.

Impact: EAT plays an important role in the progression of HFpEF and may be a promising therapeutic target.

Keywords: Heart Failure, Hypertension, Heart, Heart Failure

Motivation: Myocardial strain has been poorly studied in different stages of heart failure in hypertensive patients.

Goal(s): This study assessed the clinical utility of Cardiac Magnetic Resonance (CMR) Feature Tracking technology in evaluating left atrium and left ventricle strain parameters in hypertensive patients at different stages of heart failure.

Approach: The study compared the differences in left atrial and left ventricular strain parameters in hypertensive patients at different stages of heart failure.

Results: The results revealed varying degrees of impairment in left atrial and left ventricular strain parameters in hypertensive heart failure patients , along with a significant correlation between these parameters.

Impact: Among hypertensive patients at different stages of heart failure, the GPCS and GPLS parameters demonstrated superior diagnostic value.

Keywords: Heart Failure, Cardiomyopathy

Motivation:  The association between myocardial tissue characteristics detected by cardiac magnetic resonance (CMR) and heart failure with preserved ejection fraction (HFpEF) in hypertrophic cardiomyopathy (HCM) remains unclear.

Goal(s): We sought to evaluate the role of myocardial tissue characteristics detected by CMR in the identification of HFpEF in HCM.

Approach: CMR was used to access tissue characteristics including native T1 values, extracellular volume fraction (ECV) and indexed ECV (iECV).

Results: Native T1 was a sensitive biomarker independently associated with the diagnosis of HFpEF-HCM.

Impact: The inclusion of myocardial tissue characteristics by cardiac magnetic resonance in the diagnostic algorithms of heart failure with preserved ejection fraction in patients with hypertrophic cardiomyopathy should be considered in clinical practice and future studies.  

Keywords: Myocardium, Cardiomyopathy

Motivation: The assessment of early morphology and functional reverse remodeling of the heart is significant for HOCM patient prognosis.
 

Goal(s): This study aimed to evaluate the early cardiac morphology and function in HOCM after transapical beating-heart septal myectomy (TA-BSM) using CMR.

Approach: 41 HOCM patients who underwent CMR before after TA-BSM were prospectively enrolled in the study. Preoperative and postoperative cardiac morphological and functional parameters were compared.

Results: LVEF, wall thickness, LVMI, and LVRI decreased after TA-BSM. The △LVOTG and baseline LVMI were independently associated with greater left ventricular mass regression.

Impact: Surgery relieves the mechanical stress overload of the left ventricle (LV) and greatly improves the LV hyperdynamic state. It is essential to evaluate left heart morphology and function accurately after TA-BSM.

Keywords: Radiomics, Radiomics, Fabry Disease

Motivation: The assessment of clinical severity of Fabry disease (FD) is challenging. The radiomics analysis of CMR in patients with FD has not been studied.

Goal(s): The aim of this study was to establish radiomics classification model by using CMR cine images to distinguish FD patients from normal volunteers.

Approach: The classification model was built by linear SVM model with the top five features selected through ANOVA features selection.

Results: Our model presented good performance with mean AUC of 0.88±0.03. The top 5 features were significantly different (p<0.05) between FD patients and normal volunteers. The selected radiomics features were associated with max. LVWT.

Impact: Radiomics analysis of CMR cine images can be used to distinguish FD patients from normal volunteers. The radiomics features may suggest a pathological association with LV remodeling.

Keywords: Myocardium, Myocardium

Motivation: Myocardial fat infiltration is the key pathological features of Duchenne muscular dystrophy associated cardiomyopathy. Magnetic resonance spectroscopy is a valuable method for detecting the in vivo changes of cardiac metabolism noninvasively.

Goal(s): To investigate the characteristics of myocardial tissue triglyceride content in DMD by non-invasive MRS.

Approach: Twenty patients with DMD and Controls underwent cardiac MRI, including spectral sequence. The peak area and the area under the peak of H₂O and TG in each voxel were calculated. The t-test whether the sample mean was significant.

Results: The difference of  TG content between DMD children normal group and the two groups was statistically significant.

Impact: Cardiac magnetic resonance spectrum can reflect myocardial triglyceride relative quantity for myocardial lipid content in the different stages of disease on how to change.

Keywords: Myocardium, Cardiomyopathy

Motivation: Myocardial microvascular disease is widespread in cardiovascular disease and is associated with an increased risk of adverse events. MyoTT, as a relatively novel, non-invasive, and easy-to-perform CMR parameter, played an important role in the diagnosis of disease.

Goal(s): The study aims to observe the differences in myocardial microcirculation time between normal subjects and HCM patients.

Approach: In this study, the CMR resting-state first-pass perfusion imaging sequence was used to measure the change of signal intensities from the coronary ostium to the coronary sinus to calculate the blood circulation time. 

Results: Patients with HCM had a significantly prolonged MyoTT compared to controls

Impact: MyoTT could be easily added to current CMR protocols and does not prolong CMR scan time. And future studies are required to evaluate the diagnostic as well as prognostic value of MyoTT in different cardiovascular diseases.

Keywords: Myocardium, Cardiovascular

Motivation: Hemodialysis is a common risk factor for cardiovascular disease. Left atrial function and strain are effective predictors of cardiovascular morbidity and mortality.

Goal(s): The aim was to assess the alterations in left atrial function and strain following hemodialysis, with the objective of enabling early diagnosis of cardiac changes and risk stratification in patients with chronic kidney disease (CKD).

Approach:  Patients with advanced CKD were enrolled, including those who had not started hemodialysis and those who had started regular hemodialysis. Left atrial function and strain parameters were compared between the two groups.

Results: Left atrial function and strain deteriorated with increasing hemodialysis age.

Impact: Early detection of left atrial function and strain changes and timely intervention are of great significance for the prevention of adverse cardiovascular events in patients with CKD.

Keywords: Myocardium, Cardiovascular, Chronic thromboembolic pulmonary hypertension; cardiovascular magnetic resonance; prognosis; ventricular remodeling

Motivation: While cardiovascular magnetic resonance (CMR) is a well-established tool for assessing heart remodeling and predicting outcomes, its application in Chronic thromboembolic pulmonary hypertension (CTEPH) has received limited attention.

Goal(s): This study investigated whether biventricular remodeling derived form CMR could predict adverse clinical outcomes during the long-term follow-up of CTEPH patients.

Approach: Establish a CMR-only model and compare its predictive value with the model that combines clinical data and invasive RHC.

Results: CMR-derived biventricular remodeling have prognostic value in long-term follow-up CTEPH. Risk assessment based on CMR alone is at least as effective as that of clinic combined RHC.

Impact: These findings contribute to the optimization of early patient care and timely intervention. it's advisable to add CMR parameters in the management score. And performing noninvasive CMR alone is sufficient, as it also demonstrates excellent predictive efficacy.

Keywords: Myocardium, Cardiovascular

Motivation: Cardiac abnormalities and arrhythmias increased risk of cardiovascular mortality especially in patients with Chronic Kidney Disease (CKD).

Goal(s): To provide objective and subjective assessment in supproting the feasibility of deep learning acqusition and reconstruction cardiac magnetic resonance (CMR) imaging in patients with Chronic Kidney Disease (CKD).

Approach: Qualitative and quantitative evaluation of Sonic DL-based CMR images including breath-hold acquisition within one-beat-interval, free-breathing acquisition in comparison with traditional cine images.

Results: Sonic DL significantly accelerated acuqisition time (e.g. 11 seconds) but offered diagnosis-suffcient image quality and reliable strain values ompared to conventional sequences.

Impact: Sonic DL cine MRI showed equivalent image quality to conventional one, offered reliable strain values for diagnosis of a CKD patient lack of breath-hold ability and presentce with arrhythmias. Even it acquire a whole heart cine image in 11 seconds.

Keywords: Myocardium, Heart, cardiac function

Motivation: To solve the problem that cardiac magnetic resonance requires ECG gating and breath holding

Goal(s):  To evaluate the feasibility of cine images acquired through cardiac magnetic resonance (CMR) Multitasking and compare with those measured through multi-breath-hold bSSFP sequence in clinical setting

Approach: Study design to test the hypothesis
 

Results: Left ventricular ejection fraction was not significantly different between the two sequences in both healthy volunteers and patients.
 

Impact: Multitasking can be used to quantify the LV functions without ECG gating or breath holding in healthy volunteers and patients. Multitasking may become a replacement of bSSFP in certain conditions.

Keywords: Myocardium, Cardiomyopathy, non-compaction , cardiac diffusion tensor imaging, cDTI

Motivation: Left ventricular non-compaction cardiomyopathy (LVNC) is characterized by the presence of excessive trabeculation in the left ventricle.

Goal(s): To characterize the myocardial microstructure of LVNC patients in comparison to healthy controls using cardiac Diffusion Tensor Imaging (cDTI).

Approach: Second order motion compensated spin echo cardiac DTI was acquired in six LVNC patients and six healthy controls. Myocyte aggregate orientation is characterized by helix angle and relative percentage of right handed helical orientated myocytes.

Results: In the compacted myocardium, LVNC patients exhibited lower endocardial helix angles and a loss of the endocardial right handed helix when compared to controls.

Impact: Our findings indicate that in LVNC patients, a portion of the endocardial helix is dissolved into the non-compacted myocardium, which may impair optimal myocardial contraction in the affected segments as well as apical rotation as observed in LVNC patients.

Keywords: Myocardium, Radiomics

Motivation: DTI data in the heart are currently averaged to yield per-patient values that cannot detect local variations in the microstructural microenvironment.

Goal(s): We aimed to develop a voxel-based phenomapping approach to cluster the voxels in the myocardium into distinct groups based on their microstructural properties.  We then used the  approach to compare subjects with aortic stenosis (AS) to age-matched controls (CTL).

Approach: A population matrix of voxels was created using z-score normalization and evaluated with k-means clustering (k=4).

Results: 4 distinct clusters of voxels were present, each with different microstructural properties. No significant differences were seen between the AS and CTL subjects.

Impact: An approach to perform voxel-based phenomapping of DTI data in the heart was developed and used to classify the voxels in the myocardium into distinct microstructural clusters.  

Keywords: Myocardium, Diffusion Tensor Imaging

Motivation: Segmentation is central to cDTI post-processing, but remains subjective, time-intensive, and observer-dependent. Faster methods are needed.

Goal(s): To develop and validate a U-Net for automating and standardizing left ventricle segmentations for cDTI. Our target was for U-net generated masks to yield cDTI metric maps within 5% of ground-truth and Dice scores comparable to a human reader.

Approach: We developed a U-Net to automatically segment cDTI data then compared generated masks to expert annotations.

Results: Median Dice score was 0.79 with cDTI metrics within 5% of ground truth. A multiple-reader study demonstrated the need for further generalization of datasets at different resolutions.

Impact: An automated U-Net approach to cardiac DTI segmentation of the left ventricle minimizes segmentation variability, reduces processing time, and preserves cDTI metric measurement accuracy.

Keywords: Myocardium, Heart, Diffusion tensor imaging, Cardiac magnetic resonance, Myocardium, Swine model

Motivation: Diffusion tensor cardiac magnetic resonance (DT-CMR) has shown potential for non-invasive characterization of myocardial fiber orientation.

Goal(s): The purpose of this study is to validate the accuracy of high-resolution DT-CMR in evaluating the arrangement of biventricular myocardial fibers in a miniature-swine model, using histological findings as the reference standard.

Approach: High-resolution ex-vivo DT-CMR data of one healthy miniature-swine were acquired by a 3.0 T MRI system. Helix angles (HAs) in each segment from DT-CMR was compared with that from histology.

Results: HAs evaluated by DT-CMR were closely correlated with those derived from histology (r = 0.958, P < 0.001) in 64 myocardial segments.

Impact: Using histological validation in a miniature-swine model, high-resolution DT-CMR demonstrated good performance in non-invasively evaluating the arrangement of biventricular myocardial fibers. It provides histological evidence for DT-CMR to add more diagnostic and prognostic information in human cardiovascular diseases.

Keywords: Myocardium, Cardiomyopathy

Motivation: Cardiac MRI with diffusion-weighted imaging (DWI) non-invasively characterizes myocardial infarction, potentially identifying salvageable 'gray zone' areas without contrast agents.

Goal(s): This study aimed to evaluate the diagnostic value of DWI combined with T1 mapping, ECV, and LGE in assessing viable myocardium in acute MI patients.

Approach: By comparing ADC values across infarcted, peri-infarct, and healthy myocardium, significant ADC discrepancies highlighted the viability of the 'gray zone.'

Results: These findings could influence treatment strategies to recover endangered myocardium, enhancing clinical outcomes in acute myocardial infarction scenarios.

Impact: Investigating the 'gray zone' through CMR DWI sequences and ADC value changes, this study advances our understanding of myocardial viability in acute MI, potentially guiding interventions to salvage myocardium and improve patient outcomes in acute ischemic events.

Keywords: Myocardium, Diffusion Tensor Imaging

Motivation: The non-invasive imaging evaluation of myocyte disarray in hypertrophic cardiomyopathy (HCM) is still challenging.

Goal(s): We aimed to explore the myocardial microstructural characteristics of HCM by in-vivo cardiac diffusion tensor imaging (cDTI).

Approach: We prospectively enrolled thirty-five HCM patients and fifteen healthy controls for cDTI at 3.0T scanner.

Results: Myocardial disarray and abnormal microstructural dynamics of HCM can be characterized by in vivo cDTI. Moreover, cDTI allows early identification of myocardial microstructural changes, even before cardiovascular magnetic resonance (CMR) signs of fibrosis and hypertrophy.

Impact: Our findings shed light on the potential of cDTI for the early detection of myocyte disarray, further improving the value of CMR in the non-invasive myocardial tissue characterization of HCM.

Keywords: Myocardium, Cardiovascular, Fibrosis

Motivation: T1ρ mapping is an emerging non-contrast pulse sequence for measuring cardiac fibrosis, but current techniques suffer from lack of coverage, poor spatial resolution, and long scan time.

Goal(s): We aimed to develop an accelerated, free-breathing 3D cardiac T1ρ mapping pulse sequence using XD-GRASP reconstruction extended to include both respiratory and spin-locking time dimensions.

Approach: Our 3D T1ρ sequence was tested in 12 patients undergoing clinically indicated cardiac MRI to compare T1ρ with extracellular volume fraction (ECV) and late gadolinium enhancement (LGE).

Results: Myocardial T1ρ correlates with ECV of non-ischemic myocardium but not with a mixture of acute and chronic ischemic myocardium.

Impact: 3D T1ρ mapping achieves robust image quality and T1ρ values that agree with literature. 3D  T1ρ could be used for measuring fibrosis in patients where contrast should be avoided, after further research into the nature of T1ρ in focal scar.   

Keywords: Myocardium, Cardiomyopathy, T1rho

Motivation: This study employs T1rho imaging to examine myocardial changes in the LGE grey zone of patients with myocardial infarction, presenting a possible non-invasive approach for patients who cannot undergo contrast-enhanced procedures.

Goal(s): provide a possible non-invasive approach for patients who are unable to undergo contrast-enhanced surgery.

Approach: This study employs T1rho imaging to examine myocardial changes in the LGE gray area in patients with myocardial infarction.

Results: T1rho localization provides a viable diagnostic tool for the detection of diffuse myocardial fibrosis in patients with infarction.

Impact: This study explores the potential of T1rho in evaluating the tissue characteristics of gray myocardium adjacent to infarcted myocardium to provide a new clinical, non-invasive, accurate, and contrast-free method for monitoring diffuse fibrosis in the myocardium. 

Keywords: Myocardium, Cardiovascular

Motivation: Most cardiac T1ρ mapping techniques collect data in 2D, while the few existing 3D methods use a Cartesian sampling trajectory. 

Goal(s): In this study, we report the first use of a 3D radial trajectory for whole-heart T1ρ mapping at 1.5 T. 

Approach: The proposed technique was validated in a phantom, tested in one volunteer, and compared to a 2D reference method. 

Results: Our results show that the T1ρ values obtained from our 3D technique are comparable to the 2D reference values for both phantom and volunteer. However, we observed an underestimation of the T1ρ values using the 3D method in the phantom.  

Impact: 3D radial free-breathing electrocardiogram-triggered cardiac T1ρ mapping at 1.5 T has the potential to serve as a contrast agent-free adjunct to late gadolinium enhancement imaging for the whole-heart motion-robust quantification of tissue properties such as myocardial fibrosis.

Keywords: Myocardium, Quantitative Imaging

Motivation: We aim to develop a new method based on multi-compartment modeling to quantify myocardial tissue composition using MOLLI T1 mapping sequence. 

Goal(s): In this pilot study, we evaluated how the cardiac function, respiration, and age may impact the quantification. 

Approach: Data were acquired at end-systole/diastole, and end-expiration/inspiration. A series of maps were derived, including T1/T2 relaxation times, and fractions of three compartments: macromolecular proton, bound water and free water pools.

Results: The changes found in bound water and free water quantification matched human physiology. The developed method could provide a new non-invasive imaging tool for mapping tissue composition.

Impact: Quantifying myocardial tissue composition is valuable but very challenging. This pioneering work quantifies myocardial bound water and free water in a single breath-hold scan. It reveals the underlying tissue microstructure, which may open a new door for many applications.

Keywords: Myocardium, Cardiovascular, Transplant, Heart Transplant, Ischemia, Ischemic Cardiomyopathy

Motivation: Ischemic dilated cardiomyopathy (DCM) is associated with low-grade chronic inflammation which may persist after heart transplantation (HTx) and impact graft function and tissue characteristics in the post-HTx period.

Goal(s): Our goal was verify whether any difference in graft tissue characteristics or function was evident during long-term follow up by cardiac MRI between patients transplanted for ischemic DCM and those transplanted for non-ischemic indications.

Approach: Longitudinal analysis of graft tissue mapping and 2D FTS was performed on patients transplanted for ischemic DCM (n=13) and non-ischemic indications (n=50).

Results: In the non-ischemic DCM cohort, tissue mapping and FTS parameters, ECV and GCS, worsened over time.

Impact: No effect of pre-HTx low grade inflammation was evident on graft tissue characteristics and function in patients transplanted for ischemic DCM. Cardiac MRI may play an important role in long term monitoring of patients undergoing HTx. 

Keywords: Myocardium, Quantitative Imaging

Motivation: Motivated by the time-consuming process of dictionary matching in quantitative cardiac MRI, this study aims to develop a faster and more accurate method for myocardial multi-parametric quantitative mapping. 

Goal(s): The goal is to overcome the limitations of discretization errors and incomplete inversion pulses, which lead to inaccurate parameter estimation. 

Approach: The proposed approach utilizes Bloch equation simulation-based fitting, enabling rapid reconstruction of T1, T2, and T1ρ maps simultaneously.

Results: Experimental results demonstrate excellent quality of fit and significant acceleration (100x) compared to the traditional method.

Impact: This novel method has the potential to revolutionize myocardial quantitative mapping, offering improved efficiency and precision in clinical applications.

Keywords: Myocardium, Myocardium, T2mapping

Motivation: We focused on the similarity between 3D T₂prep T₂ mapping and whole-heart MRCA and developed a new sequence for simultaneous T₂ mapping and MRCA sequence.

Goal(s): Our goal of this study is to validate the simultaneous acquisition of 3D T₂ mapping with whole heart MRCA.

Approach: We visually assessed the image quality of 3D T₂ mapping and MRCA. T₂ values were compared with 2D T₂ mapping (2D-GRASE).

Results: This method, which enables simultaneous acquisition of 3D T₂ mapping and MRCA, can provide stable image quality and T₂ values.

Impact: Our method, which enables simultaneous acquisition of 3D T₂ mapping and MRCA, can provide stable image quality and T₂ values, and will be of great benefit in future imaging.

Keywords: Data Processing, Contrast Agent

Motivation: Late Gadolinium Enhancement (LGE) imaging is the gold-standard CMR imaging for distinguishing heart tissue viability. However, not all patients can receive gadolinium-based contrast agent. Native T₁ have been proposed in place of LGE.

Goal(s): This study explores pre-contrast cardiac MRF T₁ and T₂ measurements as potential indicators of ischemic myocardial scar.

Approach: Native T₁ and T₂ values were measured using cMRF in eleven ischemic patients using ROIs in both scar and non-scar myocardial tissue identified through LGE imaging.

Results: Native cMRF measurements differ between scar and non-scar areas. Synthetic images from these maps highlight scar tissue, offering a potential LGE imaging alternative.

Impact: Native cMRF T₁ and T₂ maps and synthetic images derived from these maps may enable differentiation of scar tissue from viable myocardium without the need for gadolinium-based contrast agents.

Keywords: Myocardium, Radiomics

Motivation: Diffusion tensor imaging of the heart can be performed with sub-mm resolution. However, established metrics do not fully take advantage of this improved resolution.

Goal(s): We aimed to determine whether local gradients in helix angle (HA) could be calculated and used to characterize the microstructural response of the heart to the load imposed by aortic stenosis.

Approach: Voxel-wise maps of radial, circumferential, minimum and maximum HA gradients were generated.

Results: The radial HA gradient was reduced in aortic stenosis, but microstructural coherence was well preserved in these patients despite a marked increase in the thickness of the myocardium. 

Impact: DTI of the heart with sub-mm in-plane resolution allows maps of local HA gradients to be generated, providing novel insights into the microstructure of the heart.

Keywords: Myocardium, Tissue Characterization, Cardiac Diffusion Tensor Imaging, cDTI, Heart, Data Analysis

Motivation: cDTI is a useful method for evaluating cardiac microstructure with proven clinical utility. To better enable the use of cDTI in the diagnosis of various cardiomyopathies, establishing quantitative baseline values in healthy subjects is needed.

Goal(s): Goal: To quantify healthy baseline cDTI metrics on a regional basis to understand normal regional differences in cDTI metrics.

Approach: Healthy volunteers received a cDTI exam covering the entire LV. Regional and global analyses of cDTI metrics were completed using the AHA 16-segment model.

Results: Statistically significant regional differences were found across all parametric maps, with the majority of them in basal segments.

Impact: Characterizing regional differences in cDTI measures provides data to define healthy baseline values for several cDTI metrics. Defining this baseline regionally provides a normative database for understanding patient-specific changes in these quantitative diffusion metrics.

Keywords: Vessel Wall, Data Analysis, Vessel Wall Morphological Measurements; Whole-Body Fat Distribution

Motivation: Obesity is associated with cardiovascular diseases. However, its effect on cerebrovascular disease remains unclear.

Goal(s): To investigate the correlation between morphological measurements of intra- and extracranial arterial vessel walls and whole-body fat distribution characteristics.

Approach: A total of 98 volunteers underwent three-dimensional high-resolution MR vessel wall imaging and whole-body MR proton density fat fraction (PDFF) imaging on a 3.0T MRI scanner.

Results: The results indicate that the vessel wall thickness of both the extracranial carotid artery and vertebral artery is positively correlated with visceral adipose tissue and the liver-PDFF.

Impact: The assessment of vascular health in individuals with central obesity necessitates a comprehensive evaluation of both extracranial carotid arteries and vertebral arteries. This paradigm shift may have far-reaching implications for the prevention and treatment of cerebrovascular diseases associated with obesity.

Keywords: Flow, Vessels

Motivation: Local stiffness of intracranial arteries may provide regional assessment of vessel changes and information about vessel pathologies, but so far there is no reliable method to measure it.

Goal(s): To propose a black-blood MRI technique with submillimeter isotropic resolution and multiple cardiac phases, and to explore its feasibility of measuring local stiffness of intracranial arteries.

Approach: A novel time-resolved 3D black-blood cine MRI was proposed combining MERGE, golden-angle radial, retrospective gating, and GRASP reconstruction. MOCHA pipeline was used to measure cardiac-driven lumen changes.

Results: Images obtained with our proposed technique can capture cardiac-driven lumen area changes that are essential for local stiffness measurement.

Impact: The proposed method, after validation, can serve as a unique local stiffness measurement tool for intracranial arteries that will highly benefit vascular imaging studies.

Keywords: Vessel Wall, Vessels

Motivation: In this retrospective observational cohort study, we found that both CAWE pattern and aspect ratio were independent predictors of aneurysm recurrence after stent-assisted coil embolization.

Goal(s): To explore the baseline clinical and imaging characteristics which can predict aneurysm recurrence after stent-assisted coil embolization.

Approach: 3D high-resolution MRI vessel wall imaging

Results: Among the 155 patients, 26 patients (16.7%) got aneurysm recurrence after stent-assisted coil embolization during the 2-year follow-up.  Multivariate logistic regression analysis revealed that the CAWE pattern (OR 3.87, 95% CI 1.2–10.4, p=0.02) and aspect ratio (OR 2.1, 95% CI 0.6-4.2, p=0.03) were independently associated with aneurysm recurrence after stent-assisted coil embolization.

Impact: If validated in future larger-scale studies, preoperative imaging characteristics, especially vessel wall enhancement patterns on 3D HR-VWI could be a potential tool for identifying patients at elevated risk of recurrence after stent-assisted coil embolization.

Keywords: Vascular, Blood vessels, vessels; TOF; Angiography

Motivation: Clinicians express concerns about false-positive findings, leading to uncertainties in the reliable interpretation of TOF-MRA.

Goal(s): This study focuses on improving the reliability of TOF-MRA for cerebrovascular imaging.

Approach: By incorporating a small flip-angle spatially-selective fat-suppression and utilizing the shortest echo-time, signal loss is minimized, and uniform fat-suppression is achieved.

Results: The results, compared to conventional protocols, demonstrate superior quality and reliability by reducing spin-dephasing and achieving uniform fat-suppression without compromising blood signal quality or requiring extensive post-processing. This approach effectively mitigates the risk of false-positive findings and overestimation of stenosis, potentially establishing it as a more effective routine clinical examination for MRA.

Impact: By improving the reliability of TOF-MRA through optimized fat-suppression and echo-time reduction, it enhances the accuracy of evaluating cerebrovascular abnormalities. This advancement enables clinicians to have greater confidence in interpreting TOF-MRA images and reduces the risk of false-positive findings.

Keywords: Vascular, Vessels

Motivation: Time-of-flight MRA (TOF-MRA) is sensitive to abnormal blood flow and result in susceptibility artifact signal and signal loss in distal small artery.

Goal(s): To investigate whether zero echo time MRA (zTE-MRA) could improve the image quality in intracranial artery with the same scan time.

Approach: Recruiting healthy subjects and taking zTE-MRA and TOF-MRA scanning.

Results: Compared with TOF-MRA using the same scan time, zTE-MRA could reduce susceptibility artifact signal in intracranial curved artery and suppress tissue signal intensity surrounding artery to better show ophthalmic artery.

Impact: Providing a non-invasive method to better reduce susceptibility artifact signal in intracranial curved artery and suppress tissue signal intensity surrounding artery to better show distal small artery.

Keywords: Flow, Fat, time-of-flight, phase-sensitive, water-fat separation, fat suppression

Motivation: Efficient fat suppression can improve flow visualization in time-of-flight (TOF) MRA. We hypothesize that the phase difference of water and fat may be used for efficient fat suppression for out-of-phase (OP) TOF MRA.

Goal(s): To demonstrate the feasibility of fat suppression for spiral TOF with sliding-slice localized quadratic (ssLQ) encoding using the phase-sensitive approach.

Approach: After the general reconstruction of ssLQ OP TOF, the global slowly varying phase was estimated and removed. Water and fat voxels were then identified according to their phase.

Results: Background suppression was substantially improved with the proposed method, resulting in enhanced visualization of small vessels.

Impact: The proposed phase-sensitive approach requires no changes of pulse sequence and negligible computational cost. It might be implemented with a wide range of OP TOF MRA for fat suppression.

Keywords: Atherosclerosis, Atherosclerosis, High-resolution magnetic resonance vessel wall imaging; Systemic Inflammatory Response Index

Motivation: The activation of inflammation can aggravate plaque rupture, thrombosis and cause brain tissue ischemia and infarction. Looking for reliable inflammatory markers might provide potential targets for the treatment of atherosclerosis patients.

Goal(s): We investigated the relationship between systemic inflammatory response index (SIRI)and intracranial plaque features, as well as the risk factors related to the severity of cerebral ischemic events. 

Approach: Compare the differences in imaging features and SIRI among patients with transient ischemic attack, mild stroke, and moderate-severe stroke.

Results: SIRI levels were significantly associated with plaque vulnerable characteristics and burden. Higher SIRIlevels and plaque featureswere independently related to moderate-severe stroke.

Impact: Our study suggested that immune inflammation may have adverse effects on intracranial atherosclerosis, and link to the severity of cerebral ischemic events. Therefore, the regulation of immune inflammation may be a potential therapeutic target for sICAD.

Keywords: Flow, Velocity & Flow, aneurysm

Motivation: The research aims to investigate the changes in hemodynamics in intracranial aneurysms before and after treatment with blood flow shunt stents treatment.

Goal(s): The technical goal is to quantify common hemodynamic parameters, and use statistical comparison to analyze the variation patterns.

Approach: A set of program was utilized to separate aneurysms from complex environments, calculate hemodynamic values within the region, and analyze the trend of changes in preoperative and postoperative data.

Results: The results of simple statistical analysis showed that the average flow velocity, average WSS and OSI at the aneurysm presented a decreasing trend in different degrees after the shunt stent treatment.

Impact: In this study, the number of subjects and hemodynamic parameters can be increased to obtain more comprehensive experimental results. Researchers can also focus on the relationship between aneurysm stability and hemodynamics, and establish corresponding prediction and evaluation models.

Keywords: Flow, Cardiovascular, neuroprotection in cardiac surgery

Motivation: Cerebral injury following deep hypothermic circulatory arrest (HCA) remains an important clinical problem in cardiac surgery.  Investigating mechanisms of neuroprotection and establishing clinically efficient means to assess acute brain injury following HCA has been the cornerstone of our laboratory's work. 

Goal(s): Identify mechanism of cerebral injury following HCA. Establish accurate and efficient mechanisms for diagnosing acute brain injury following HCA.

Approach: Double blinded, prospective, randomized large animal study using canines and multiple neurobehavioral testing instruments including clinically validated methods and pCASL MR imaging.

Results: Cerebral blood flow corroborates with clinically validated neurobehavioral scoring instruments in a canine model of HCA.

Impact: By employing highly effective mechanisms for acute brain injury diagnosis and matching these with ongoing RO1-funded mechanism of neuroprotection following HCA, we aim to impact all cardiac patients in the world who may need deep hypothermic circulatory arrest.

Keywords: Atherosclerosis, Atherosclerosis, High resolution magnetic resonance vascular wall imaging, Middle cerebral artery, Acute ischemic stroke

Motivation: The occurrence of acute ischemic stroke (AIS) in patients with middle cerebral artery (MCA) atherosclerosis is related to the status of atherosclerotic plaque itself and level of homocysteine (Hcy) and glycated hemoglobin (HbA1c).

Goal(s): To analyze wall characteristics and clinical indicators in patients with MCA atherosclerosis with a view to finding predictors of AIS events.

Approach: We gathered data from 38 participants, segregated them into the AIS and transient ischemic attack (TIA) groups, and subjected the data from both groups to statistical analysis.

Results: Combined stenosis rate and Hcy have higher value for predicting AIS events.

Impact: Hcy and stenosis rate were independent risk factors for AIS events in patients with MCA atherosclerosis; combined Hcy and stenosis rate had a higher predictive value of AIS events.

Keywords: Vessel Wall, Blood vessels

Motivation: Manual centerline Extraction based on black-blood Magnetic resonance vessel wall imaging is a difficult and time-consuming but important step for further analysis of plaques. 

Goal(s): To propose a method for quickly, automatically and accurately extracting the centerline and label the segments of the target arteries.

Approach: This study proposes a method that combines deep learning and traditional graphics method for the automatic and accurate centerline extraction and even segments labeling, which is applicable to flexible MR sequences (only black-blood images, only bright-blood images, or both).

Results: Compared with the ground truth, the proposed method achieved excellent completeness and accuracy in a short time.

Impact: This study introduces a flexible (MRVWI or/and TOF-MRI), swift, and precise approach for extracting and labeling the centerline of target vessel. With this method, radiologists can more conveniently and efficiently observe potential abnormal areas around vessel and diagnose vessel-related diseases.

Keywords: Vascular, Brain

Motivation: There is limited understanding regarding the physiological mechanisms underlying the impact of coronary artery disease (CAD) on brain health.

Goal(s): In this study, we sought to explore the influence of CAD on vascular and metabolic biomarkers.

Approach: Specifically examining Cerebrovascular Reactivity (CVR), Cerebral Blood Flow (CBF), and Oxygen Extraction Fraction (OEF) in the brain, and how these factors relate to cognitive performance.

Results: Our initial findings, based on a preliminary dataset, indicate that individuals with CAD exhibit reduced CBF and CVR, with increased OEF across several brain regions. Low CVR and high OEF are also associated with poorer executive function in these regions.

Impact: The influence of coronary artery disease (CAD) on brain health remains unclear. We show that CAD is associated with elevated OEF and reduced CVR and CBF. High OEF and low CVR are linked to poorer cognition, especially executive functions.

Keywords: Vessel Wall, Vessels, Vessel wall imaging, blood suppression

Motivation: The intrinsic “black-blood (BB)” property in 3D TSE is insufficient for vessel wall imaging and other neuroimaging applications. Additional blood suppression preparations can diminish T1 weighting and SNR.

Goal(s): To develop and validate a new approach compatible with 3D TSE to enhance BB effects while minimizing sacrifice in T1 weighting and overall SNR.

Approach: An interleaved flow-sensitive dephasing scheme was developed, and verified in healthy volunteers and assessed in 32 patients with one of four neurological diseases.

Results:  iFSD-SPACE achieved the lowest lumen SNR and the highest wall-lumen CNR. iFSD-SPACE yielded significantly higher white-matter SNR and gray-to-white matter CNR than DANTE and MSDE.

Impact: iFSD is a 3D TSE-compatible blood flow suppression technique that overcomes the limitations of existing BB magnetization preparation methods and holds the potential to greatly enhance the performance of 3D TSE in several neuroimaging applications.

Keywords: Vessel Wall, Vessels, GRASP, MRA

Motivation: The mortality and disability rates following cerebral aneurysm rupture remain significantly high. Recently, pulsation of aneurysms has been suggested as a novel risk factor of rupture.

Goal(s): To harness the ultra-high temporal resolution and signal-to-noise ratio of the modified GRASP technique with 7T MRI to visualize pulsatile motions of cerebral aneurysms.

Approach: A pulsatile aneurysm phantom and aneurysm patient were scanned using a 3D-cine MRI technique, aiming to capture dynamic aneurysmal wall movements at high spatial and ultra-high temporal resolution.

Results: The new imaging technique successfully depicted pulsatile movements in the aneurysm phantom and subject, suggesting a novel predictor for aneurysm rupture.

Impact: This study presents a 3D-cine MRI method at 7T, capturing aneurysm pulsations with ultra-high frame rates in the tens of milliseconds range, promising to refine rupture risk assessments and potentially reducing adverse outcomes in cerebral aneurysm management.

Keywords: Vessel Wall, Cardiovascular

Motivation: Atherosclerotic proteins have been implicated with inflammation and remodeling of aneurysm wall. Both aneurysm wall enhancement (AWE) and irregular pulsation have been suggested as potential candidates for intracranial aneurysms (IAs) instability. 

Goal(s): To explore the association between atherosclerotic proteins and AWE and irregular pulsation. 

Approach: Using vessel wall MRI and four-dimensional computed tomography angiography

Results: We found higher level of serum Lp(a) (Lipoprotein[a]) was significantly associated with increased wall enhancement and irregular pulsation of IAs (both p<0.05)

Impact: This study established a link between atherosclerotic proteins and AWE and irregular pulsation, inflammation and wall remodeling.

Keywords: Atherosclerosis, Atherosclerosis, Angiography, whole-heart

Motivation: Coronary artery disease remains a significant problem worldwide and current methods for anatomical assessment involve ionising radiation and iodinated contrast agents. 

Goal(s): To develop a novel free-breathing, 3D whole-heart, coronary magnetic resonance angiography sequence with high spatial resolution for the assessment of coronary anatomy and coronary artery disease.

Approach: Nine patients referred for assessment of suspected coronary artery disease were scanned using the proposed sequence at 1.5T. Acquisitions at 0.9mm³ and 0.7mm³ were compared. 

Results: The 0.7mm³ acquisition demonstrated improved qualitative and semi-quantitative vessel visualisation and coronary stenosis detection compared with 0.9mm³ acquisition in an average scan time of <14 minutes.

Impact: This work demonstrates improved coronary artery lumen visualisation and stenosis detection compared to 0.9mm³ acquisitions, providing a further step forward towards clinical adoption as a contrast- and radiation-free alternative to CTCA.  

Keywords: Vascular, Cardiovascular

Motivation: Whole-heart-coronary-MRA (WHC-MRA) is typically performed during free-breathing, and respiratory motion is prospectively compensated by using a 1D-right-diaphragmatic-navigator. However, this method requires long acquisition time and causes a heavy burden on the patient.

Goal(s): Our goal was to obtain high-resolution WHC-MRA with single-breath-hold while ensuring clinically acceptable signal-to-ratio.

Approach: Turbo-field-echo-planar-imaging (TFEPI), a high-speed technique, was combined with deep learning constrained Compressed SENSE (CS-AI) and image quality was evaluated by visual evaluation and contrast-to-ratio.

Results: TFEPI with CS-AI provided high spatial resolution isotoropic single-breath-hold WHC-MRA while maintaining clinically acceptable image quality and scan time compared to Compressed SENSE and SENSE.

Impact: High-resolution single-breath-hold WHC-MRA with clinically acceptable image quality by 3D TFEPI with CS-AI may improve the throughput of cardiac MRI examinations, and in addition reduce patient burden.

Keywords: Flow, Motion Correction

Motivation: 3D Phase contrast MRI of the coronary arteries remains challenging due to low SNR and motion.

Goal(s): Develop a 3D PC sequence for flow quantification in the coronary arteries at 3T with improved SNR and reduced motion artefacts compared to 1.5T.

Approach: The sequence was optimized by acquiring datasets separately, enabling inter-scan motion compensation while circumventing SAR limitations. Coronary flow was quantified in 5 subjects at 3T.

Results: Phantom measurements showed reduced image artefacts using the proposed sequence. In-vivo mean peak velocities per slice along the left and right coronary arteries were 15.9±5.0cm/s and 14.1±4.9cm/s respectively. 

Impact: High SNR 3D flow measurements in the proximal coronary arteries are now possible, as SAR restrictions at 3T have been overcome. This may enable the non-invasive hemodynamic assessment of coronary arteries in patients with CAD.       

Keywords: Vascular, Cardiovascular

Motivation: To improve the image quality of the non-enhanced whole heart bTFE CMRA sequence at 3T.

Goal(s): To compare the performance of a newly improved bTFE CMRA sequence with the mDixon water-fat separation GRE method at 3T for CMRA.

Approach: Success rate, acquisition time, image quality, and diagnostic performance were compared.

Results: This study demonstrated that the performance of the 3D bTFE CMRA sequence at 3T was brilliant, with a high success rate, appropriate acquisition time, excellent image quality, and good diagnostic performance.

Impact: The non-enhanced bTFE CMRA sequence at 3T may be recommended for more extensive clinical applications.

Keywords: Vascular, Cardiovascular

Motivation: MRI at 0.55T with an 80cm bore has allowed improved access to CMR for patients. The application of robust native whole-thorax MRA at low-field remains limited especially due to the challenge of respiratory motion.

Goal(s): To develop a large field-of-view, whole-thorax, self-gated and breathing-motion corrected native MRA with a predictable scan time and efficient data usage at 0.55T.

Approach: An optimized sampling pattern is used with T2-prep, dual-echo Dixon and non-rigid motion correction is developed.

Results: The approach was successfully applied in-vivo and shows successful mitigation of motion artefacts and blurring and good separation of water and fat in the entire thoracic region.

Impact: Proof of the viability of self-gated MOCO MRA at 0.55T.

Keywords: Vascular, Cardiovascular

Motivation: Non-contrast enhanced coronary MRA is a non-invasive and non-ionizing radiation imaging technology. 3D-BTFE is the most commonly used coronary MRA sequence but is time-consuming. 

Goal(s): We compared the MSG-EPI and 3D-BTFE sequences and evaluated the value of MSG-EPI. 

Approach: The differences of image score, SNR and CNR between the two sequences were compared.

Results: We found that the image score, SNR, and CNR differ between MSG-EPI and 3D-BTFE. In lumen display of RCA and LAD, image scores of MSG-EPI were sufficient to attach diagnostic requirements and there was no significant difference in SNR. However, the CNR of 3D-BTFE was significantly higher than MSG-EPI.

Impact: This study compared MSG-EPI and 3D-BTFE sequences and found that although MSG-EPI 's image quality is slightly inferior to 3D-BTFE 's, its advantage of rapid imaging makes it promising in clinical applications.  

Keywords: Vascular, Cardiovascular, coronary

Motivation: Coronary magnetic resonance angiography (MRA) has not been widely used due to lower diagnostic accuracy. The combination of diastole and systole imaging may enhance its clinical applications.

Goal(s): Designing a coronary MRA protocol combining diastole and systole imaging and evaluating its diagnostic performance for detecting significant coronary artery disease (CAD).

Approach: 3.0-T non-contrast coronary MRA was carried out twice at diastole and systole. Significant CAD was evaluated by coronary MRA as follows:1) by diastole mode, 2) by systole mode, and 3) by combined mode.

Results: Combined coronary MRA showed equally high sensitivity but improved specificity than single diastolic mode.

Impact: This study demonstrated that 1) 3.0-T non-contrast coronary MRA using combinational diastole and systole imaging can noninvasively detect CAD with high sensitivity and moderate specificity; 2) Combining diastole and systole imaging improved the diagnostic accuracy of coronary MRA, especially specificity.

Keywords: Atherosclerosis, Atherosclerosis

Motivation: Due to the complex pathogenesis of AS formation, the clinical treatment of AS with medicine is durable and often ineffective. it is necessary to seek a new strategy that is broadly applicable to all patients for AS theranostics .

Goal(s): MM nanoparticles could delivering small molecule drugs to plaques and monitored by MR in real time upon Mn²⁺ released from AS microenvironment-responsive MnO₂ nanoparticles.

Approach: In vitro and vivo studies on 3.0T and 9.4T MR scaner. 

Results: In vitro and vivo studies showed that MM could be monitored by MR in real time upon Mn²⁺ released from acidic- and H2O₂- microenvironment-responsive MnO₂ nanoparticles.

Impact: Nanocarriers(MM) exhibited remarkable in vivo MRI monitoring of the therapeutic process with a long imaging window and good biocompatibility and biosafety. This MRI-visible nanomedicine shows immense potential as a theranostic platform for AS therapy.

Keywords: Vascular, Blood vessels

Motivation: The lower extremity MR angiography (MRA) without electrocardiography (ECG) or peripheral pulse unit (PPU) triggering and contrast enhancement is useful for diagnosing peripheral arterial disease (PAD), which can avoid synchronization failure and nephrogenic systemic fibrosis (NSF).

Goal(s): Our goal was to improve peripheral arterial depiction without ECG or PPU and contrast agent.

Approach: TSE-based enhanced acceleration-selective arterial spin labeling (eAccASL) (TSE-Acc) was compared with TFE-based eAccASL (TFE-Acc), and TRANCE as a reference standard by SIR, CNR, and visual inspection.

Results: CNR and arterial visibility score for TSE-Acc were higher than TFE-Acc, but no difference compared with TRANCE.

Impact: TSE-based enhanced acceleration-selective arterial spin labeling (eAccASL) can provide clear depiction of the peripheral arteries without ECG or PPU and contrast agent, providing sufficient diagnostic performance in PAD patients with arrhythmia and CKD.

Keywords: Flow, Cardiovascular, Catheterization, Computational Fluid Dynamics, Lumped Parameter Model, Pulmonary Vascular Resistance, Glenn Physiology, Simulation of Fontan Surgery

Motivation: Individual pulmonary vascular resistances (PVR) of the left and right lung are needed to perform in-silico virtual cardiac surgery to improve Fontan conduit designs, yielding more balanced blood flow to the lungs.

Goal(s): Predict patient-specific PVR of both lungs using clinical flow and pressure data acquired from cardiovascular magnetic resonance exams and catheterizations.

Approach: Utilize computational fluid dynamics (CFD) and lumped parameter (LP) models to iteratively optimize the PVR of both lungs.

Results: There is excellent correlation between the PVR estimates of the CFD and LP models, and both models fit to clinical outlet flow and pressure with less than 10% error.

Impact: Accurate prediction of individual lung resistances is needed for patient-specific in-silico virtual cardiac surgery to optimize the design of the Fontan conduit. This design could then be implemented by surgeons to provide more balanced pulmonary blood flow in Fontan patients.

Keywords: Flow, Velocity & Flow

Motivation: It has not been exhaustively studied how the nonlinear behavior of the blood impacts the estimation of hemodynamic parameters

Goal(s): To demonstrate the impact of nonlinear viscosities produced by diseases such as anemia and polycythemia on the estimation of hemodynamic parameters

Approach: Hemodynamic parameters were estimated from synthetically generated 4D Flow images obtained from CFD simulations of the aorta using a nonlinear model for the viscosity and different levels of nonlinearity

Results: Important differences were observed in WSS, OSI, and energy loss estimated using a nonlinear model for the viscosity compared to results obtained using constant viscosities. Comparisons were made for several cases

Impact: This investigation could impact how the MR community estimate hemodynamic parameters from 4D MR images.

Keywords: Atherosclerosis, Cardiovascular, pericoronary adipose tissue

Motivation: We attempted to assess pericoronary adipose tissue using the mDIXON sequence of magnetic resonance imaging

Goal(s): To evaluate the relationship between pericoronary adipose tissue and coronary stenosis grade and plaque type

Approach: Study design to test the hypothesis

Results: Pericoronary adipose tissue volume is independently associated with the type of coronary plaque

Impact: Magnetic resonance imaging is more accurate for the assessment of adipose tissue. This is the first time to apply MRI to the assessment of pericoronary adipose tissue, and to verify its direct relationship with coronary plaque type and stenosis grade.

Keywords: Flow, Velocity & Flow, Low-field

Motivation: PC-MRI allows for both in-vivo and in-vitro evaluation of complex flow patterns.  The accuracy and consistency of these measurements needs to be re-evaluated at new low- and mid-field strengths such as 0.55T.

Goal(s): To evaluate flow and velocity patterns using 0.55T PC-MRI to assess the scanner’s suitability for complex flow quantification.

Approach: Using an in-vitro human circulatory setup with a patient-specific type-B aortic dissection phantom to measure complex velocity fields.

Results: Excellent agreement between MRI-obtained and measured flowrates were observed. Complex rotational flow patterns were captured. Results are consistent within slices and experimental conditions, demonstrating the efficacy of 0.55T MRI for flow evaluation.

Impact: This study establishes the viability of 0.55T MRI for phase contrast imaging for three-dimensional velocity field measurements. The findings validate the consistency of flow quantification, and open new avenues for further opportunities on complex flow visualization.

Keywords: Blood Vessels, Vessels, MP2RAGE;Venous thrombosis;T1 mapping;Dante

Motivation: The aim of this work was to investigate fast T1-mapping for the characterization of deep vein thrombosis
(DVT).

Goal(s): Discuss the research value of Dante-MP2RAGE technology in venous thrombosis of the lower extremities

Approach: Select 15 patients with venous thrombosis in the lower extremities and analyze the correlation between the T1 value formed by Dante-MP2RAGE and the stage of venous thrombosis in the lower extremities.

Results: DANTE-MP2RAGE is related to venous thrombosis in the lower extremities and provides an accurate T1 value。

Impact: Without injecting contrast agents, it provides an effective quantitative indicator for the staging of venous thrombosis in the lower extremities.

Keywords: Flow, Blood vessels

Motivation: MRI-based relative pressure is a promising imaging biomarker. A new technique, vWERP, improves pressure estimations compared to more simplified approaches. Validated in clinical settings, it's unexplored in mouse models.

Goal(s): To apply the vWERP algorithm to MRI-microscopy for pressure measurements in wild-type and atherosclerotic mouse models.

Approach: 4D flow MRI was performed in wild-type and ApoE^-/- mice. Post-processing involved segmenting the aorta, defining analysis planes, and calculating pressure drops using the vWERP algorithm for analysis.

Results: Using vWERP with 4D flow MRI shows promise for studying vascular disease hemodynamics. Preliminary findings suggest pressure as a robust parameter to examine changes in CVD progression.

Impact: Application of vWERP to MRI-microscopy in mice reveals high potential for assessing cardiovascular disease progression, particularly in studying pressure changes. This new diagnostic tool benefits vascular health studies in preclinical settings and may be used to study atherosclerotic plaque development.

Keywords: Vascular, Cardiovascular, Abdominal aortic aneurysm

Motivation: To survey radiographical parameters to predict outcomes after EVAR. 

Goal(s): To reveal new MRI findings associated with aneurysmal shrinkage.

Approach: Various MRI findings were extracted from fifty patients and the relationship between each finding and aneurysmal volume change was analyzed. 

Results: Lack of endoleak, endoleak with clear boundary shapes, homogenous signal pattern or uncomplex heterogenous signal pattern of intra-aneurysmal thrombus, and aneurysmal wall enhancement and thickening were noted as the factors for sac shrinkage. 

 

Impact: Some specific MRI findings as lack of endoleak, clear endoleak boundary, homogenous or uncomplex heterogenous thrombus, and aneurysmal wall enhancement thickening were noted as the factors for sac shrinkage.  

Keywords: Heart Failure, Cardiovascular

Motivation: To investigate the cardioprotective effects of paeoniflorin on myocardial infarction-induced ventricular remodeling in high-altitude hypobaric hypoxia environments.

Goal(s): To evaluate the potential protective role of paeoniflorin in a rat model of myocardial infarction-induced ventricular remodeling under high-altitude hypobaric hypoxia using cardiovascular magnetic resonance strain analysis.

Approach: Rats were allocated to plain sham operation control, high-altitude sham operation control, high-altitude myocardial infarction operation, and paeoniflorin treatment groups. CMR assessed cardiac function.

Results: Paeoniflorin treatment groups demonstrated enhanced left ventricular function and regional strains compared to the myocardial infarction group. Histological analyses also showed reduced myocardial injury and fibrosis with paeoniflorin treatment.

Impact: The study's outcomes have implications for managing patients at risk of MI, especially those in high-altitude environments or exposed to hypobaric hypoxia.

Keywords: Atherosclerosis, Cardiovascular

Motivation: Conventional carotid artery wall MR imaging is time-consuming due to multiple MR acquisitions. MULTIPLEX, a fast single-scan MRI technique, provides T1W/PDW/T2* maps simultaneously. Its potential in evaluating arterial plaque remains unexplored.

Goal(s): Evaluating MULTIPLEX in characterising carotid plaque.

Approach: We compared T1/PD/T2* values of arterial morphology and plaque components (lipid-rich necrotic core/intraplaque haemorrhage/loose matrix) in 33 participants using ANOVA between conventional technique and MULTIPLEX.

Results: Significant T1/PD/T2* differences of plaque compositions mentioned above were found across all three groups with MULTIPLEX, similar to conventional technique. Varied plaque components displayed T1/PD/T2* differences.

Impact: MULTIPLEX shows promises in characterising arterial plaque beyond the brain.

Keywords: Heart Failure, Segmentation, Open-Source

Motivation: Cardiac magnetic resonance (CMR) image segmentation remains a time-consuming task. Deep learning (DL) segmentation models have advanced considerably in recent years, but they lack flexibility for manual adjustments.

Goal(s): We sought to develop an open-source, flexible plug-and-play inline CMR image segmentation platform.

Approach: We implemented in-house algorithms in a clinical scanner as separate Python modules, allowing new and existing DL models to be integrated into clinical workflow.

Results: We assessed the feasibility of the automated plug-and-play platform for inline cine segmentation in 308 patients referred for clinical CMR.

Impact: This platform facilitates the rapid development and evaluation of any segmentation algorithm in a transparent and reproducible fashion. An open-source, flexible, plug-and-play inline CMR segmentation platform will enable rapid testing and evaluation of new segmentation and analysis algorithms.

Keywords: Myocardium, Heart, Cardiac function, Cine MRI, Multiposture MRI

Motivation: Cardiac function is affected by body posture. However, MRI measurements have been limited to the supine posture.

Goal(s): Our goal was to evaluate the effect of body posture on cardiac function using multiposture MRI.

Approach: We assessed cardiac function in supine and standing postures in seven healthy males using a 0.4T multiposture MRI.

Results: Significant reductions in left ventricular end-diastolic volume, end-systolic volume, and stroke volume were observed in the standing posture, with increased heart rate, while cardiac output and ejection fraction remained consistent across postures.

Impact: Multiposture MRI enables the assessment of the postural effect on cardiac function and potentially provides new diagnostic insights into regulatory response to postural change.

Keywords: Flow, Velocity & Flow, Simultaneous Multi-Slice, Pulse Wave Velocity

Motivation: Pulse wave velocity (PWV) is an important biomarker for cardiovascular risk that can be measured non-invasively with phase contrast MRI. Sequential scans at different planes can lead to inaccurate measurements so an alternate approach is needed.

Goal(s): We aim to develop a 2D simultaneous multi-slice (SMS) radial phase contrast sequence to image multiple planes concurrently, reduce timing inconsistencies, and measure PWV more accurately.

Approach: The radial phase contrast SMS sequence was implemented on a GE scanner and included in an ongoing volunteer study.

Results: The SMS scan provided higher quality images in less scan time than sequential and had reduced timing inconsistencies.

Impact: Pulse wave velocity (PWV) is a clinically important biomarker for cardiovascular risk. A simultaneous multi-slice radial 2DPC sequence allows for faster, more accurate MR flow measurements with high temporal resolution and reduced timing inconsistency which can improve early detection.

Keywords: Vascular, Blood

Motivation: Current methods for measuring T1 and T2 in fetal blood are inefficient, which limits their applicability to the largest vessels in late gestation.

Goal(s): To develop a faster, more motion-robust sequence for blood T1 and T2 measurement, which can be applied in fetal subjects.

Approach: A spiral, spoiled gradient echo sequence (sp-SPGR) was developed to jointly estimate blood T1 and T2 from a single, 12 second scan. sp-SPGR accuracy was validated in adult volunteers by comparison with conventional MOLLI and T2p-bSSFP techniques. 

Results: The sp-SPGR sequence obtained T1 and T2 estimates consistent with conventional methods in approximately one-fifth the acquisition time.

Impact: As a faster, more motion robust sequence for estimating blood T1 and T2, sp-SPGR will support oximetry measurements in the fetal great vessels at earlier gestational age, facilitating more accurate and timely evaluation of fetal hypoxia. 

Keywords: Vascular, Blood vessels, Carotid Diameter, Pulsatile Motion, Angiography

Motivation: The carotid artery anatomy is routinely studied with MRI, whilst its relative diameter change is evaluated using ultrasound. An MRI technique to measure the carotid diameter change throughout the cardiac cycle could therefore be complementary to the existing toolset.

Goal(s):  To combine carotid MR angiography and diameter change quantification in one scan without contrast agent injection. 

Approach: A 4D (3D+time) free-running sequence was extended with slab-selective RF pulses to increase the inflow blood-to-muscle contrast. Carotid diameter changes and contrast ratios were quantified.  

Results: The contrast ratio significantly improved with the use of slab-selective pulses and the carotid relative diameter change was precisely measured.

Impact: 4D free-running MR angiography with slab-selective RF pulses allows for the dynamic visualization of the carotid lumen and the quantification of the relative carotid diameter change throughout the cardiac cycle without contrast agent injection.

Keywords: Vessel Wall, Atherosclerosis, intracranial artery, stroke, coronary artery

Motivation: The coexistence of atherosclerosis in coronary, and intracranial arteries has not been comprehensively assessed.

Goal(s): This study was designed to investigate the co-existence of atherosclerosis in the intracranial and coronary arteries of patients with and without ASCVD using high-resolution magnetic resonance imaging and computed tomography angiography.

Approach: The ASCVD group exhibited greater artery stenosis, as well as significant differences in lipid, calcium volumes, and lipid volume ratio compared to the non-event group. Additionally, different plaque types displayed significant variations in morphology and composition.

Results: There is a consistent pattern of change in plaque characteristics between intracranial and coronary arteries.

Impact: High-resolution magnetitic resonance imaging (hrMRI) and coronary computed tomography angiography (CCTA) to investigate the co-existence of high-risk atherosclerotic plaques in the intracranial and coronary arteries of patients with cardiovascular events. Results showed that such plaques were present in both locations.

Keywords: Atherosclerosis, Atherosclerosis, Carotid, Stroke

Motivation: We explored the relationship between intraplaque hemorrhage (IPH) and thin/ruptured fibrous cap (TRFC) or disrupted plaque surface.

Goal(s): We investigated the relationship between a TRFC/disrupted plaque surface and the change in carotid IPH volume

Approach: Longitudinal carotid MR study in 110 symptomatic patients with mild-to-moderate carotid stenosis.

Results: Baseline MR images revealed a larger IPH volume in patients with a TRFC/disrupted plaque surface and the IPH volume (tended to) decrease during  follow-up. However, part of patients with a TRFC/disrupted plaque surface at baseline had a higher risk of IPH progression.

Impact: Identifying patients at higher risk of IPH progression allows for timely monitoring and intervention, potentially reducing the incidence of stroke. This research contributes to improved quality of life for individuals at risk of carotid IPH-related complications

Keywords: Myocardium, Radiomics, Late Gadolinium Enhancement; Myocardial Infarction; Microvascular Obstruction; Random Forest;

Motivation: Late gadolinium Enhancement (LGE) is the method of choice for assessing myocardial infarction (MI) and viability, essential to guide revascularization decisions. LGE also shows no-reflow regions that occur when blood flow remains inadequate post-revascularization. Existing automatic segmentation methods identify regions of LGE uptake but ignore no-reflow regions.

Goal(s): Our goal is to provide a robust and automated solution for the detection of MI and no-reflow.

Approach: We propose two LGE-based radiomics models, RAMI and RAMI-NOR, to improve MI diagnosis and detect no-reflow, respectively. 

Results: RAMI distinguishes normal and pathological cases accurately. RAMI-NOR shows potential in assessing MI with no-reflow but needs further refinement. 

Impact: The proposed RAMI and RAMI-NOR methods extract radiomics features from LGE images to automatically detect infarcted and microvascular obstruction areas, essential for the diagnosis and treatment management of patients suffering from myocardial infarction. 

Keywords: Atherosclerosis, Atherosclerosis

Motivation: Acute care decisions, such as the initiation of anticoagulant therapy, are affected by infarction degree.

Goal(s): To assess the severity of ischemic stroke and prognosis in patients with symptomatic carotid artery stenosis, this study combined cerebral WMLs burden derived from FLAIR and carotid plaque characteristics based on HRVW-MRI to construct a noninvasive model.

Approach: Logistic regression analysis and LASSO regression analysis were utilized to develop predictive nomogram model. 

Results: The AUC of predictive model was 0.92 in the training and 0.88 in the validation cohort, and showed good clinical utility. The hybrid model-derived score was an independent predictor of mRS score.

Impact: The high discriminative ability indicates the potential of this model for classifying patients with nervous functional defect according to NIHSS score.The hybrid model-derived score is related to judge the neurological function recovery. 

Keywords: Vessel Wall, Stroke

Motivation: With the assistance of prior vessel wall mask, segmentation of atherosclerotic plaque can achieve satisfactory performance. However, manual sketching of vessel wall mask is still time-consuming.

Goal(s): To propose a method for fast and accurate plaque segmentation without relying on prior knowledge of vessel walls.

Approach: This study proposes a deep learning model based on a multi-head loss design for automatic segmentation of carotid artery plaques, with the aim of reducing dependence on prior information of vessel walls in plaque segmentation.

Results: In the independent test, the model with the multi-head loss design achieving excellent results similar to using vessel wall prior.

Impact: This study achieved fully automatic and accurate plaque segmentation without manual priors, which will greatly reduce burden of radiologist to segment and quantify plaque, and also contribute to more efficient stroke risk assessment, progress monitoring, and efficacy evaluation for patient.

Keywords: Vascular, Arterial spin labelling

Motivation: Lower-limb vascular imaging used in advanced peripheral arterial disease PAD) is limited to luminography with no functional tissue perfusion data. 

Goal(s): MRI ASL perfusion quantification is a contrast agent free technique that promises to be a novel imaging biomarker for tissue viability. However, current implementations have several limitations, including low signal-to-noise and the need for a substantial period of hyperemia to induce measurable perfusion in the muscle. 

Approach: We aimed to develop an abbreviated, clinically-practical ischemia-hyperemia paradigm to measure perfusion, and to evaluate this in volunteers. 

Results: A 2-minute period of ischemia produced hyperemia a doubling of baseline perfusion, sustained for 30 seconds.

Impact: Quantitative perfusion imaging with pseudocontinuous arterial spin labelling can be achieved in the lower limb with an ischemia-hyperemia paradigm with 2 minutes of ischemia. This clinically applicable technique can be used in the assessment of peripheral arterial disease. 

Keywords: Atherosclerosis, Stroke

Motivation: The presence of intraplaque hemorrhage (IPH) is a strong independent stroke predictor. Higher IPH signal intensity ratios (SIR) and volumes were found in symptomatic versus asymptomatic carotid arteries.

Goal(s): To determine if IPH SIR and volume are associated with the risk for ipsilateral ischemic neurovascular events in symptomatic patients with <70% carotid stenosis.

Approach: Cox proportional hazards and logistic regression were used to explore the association of IPH SIR and volume to ipsilateral ischemic neurovascular events in 87 IPH-positive patients. 

Results: IPH SIR and IPH volume were not associated with risk for ipsilateral ischemic events during 5.1(IQR:3.1-5.6) years. 

Impact: No association was found between IPH SIR or volume and the risk for ipsilateral ischemic neurovascular events or new infarcts on brain MRI. Therefore, identifying the presence of IPH is sufficient for risk stratification. 

Keywords: Vascular, Cardiovascular