Qinwei Zhang¹, Barbara Cervantes², Dimitrios C. Karampinos², Bram F. Coolen¹, Aart J. Nederveen¹, and Gustav J. Strijkers^3
1Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands, ²Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, ³Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands

 Diffusion imaging is becoming a promising alternative to contrast enhanced imaging in detecting lipid core and hemorrhage in atherosclerotic plaques. Diffusion prepared turbo spin echo sequence (DP-TSE) has been proven to be feasible to acquire 3D diffusion images of carotid vessel wall, but it has critical requirement on the eddy currents. This study demonstrates that using stimulated echo based DP-TSE sequence, together with m1 nulling diffusion gradients, and MLEV refocusing RF pulses, high resolution 3D carotid vessel wall diffusion imaging can be achieved in the presence of eddy current, motion and B₁-inhomogeneity.

Huijun Chen¹, Juan Wang², Jie Sun³, Daniel S Hippe³, Xihai Zhao¹, and Hongbing Liu^2
1Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of, ²Cardiology, People’s Liberation Army General Hospital, Beijing, China, People's Republic of, ³Radiology, University of Washington, Seattle, WA, United States

Pharmacokinetic modeling of DCE-MRI  can quantify the adventitial vasa vasorum of carotid atherosclerotic lesions using the transfer constant (K^trans). However, the relationship between the DCE-MRI quantified carotid adventitial vasa vasorum  and cardiovascular events remains unclear. In this study, we found that the adventitial K^trans of carotid artery measured by DCE-MRI was associated with cardiovascular events (cerebral ischemic events and coronary artery events), suggesting that the carotid adventitial vasa vasorum is not merely a local risk factor but also a promising systemic marker for cardiovascular risk. DCE-MRI may be valuable for identifying high risk patients in clinical practice.

Huilin Zhao¹, Shiteng Suo¹, Peipei Hao¹, Xiaosheng Liu¹, Xihai Zhao², Yongming Dai³, Chun Yuan⁴, and Jianrong Xu^1
1Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, People's Republic of, ²Center for Biomedical Imaging Research, Tsinghua University School of Medicine, Beijing, China, People's Republic of, ³Philips Healthcare, Shanghai, China, People's Republic of, ⁴Radiology, University of Washington, Seattle, WA, United States

Texture analysis with the combined set of texture features may be useful in discriminating vulnerable plaque. This study sought to determine the feasibility of texture analysis for the classification of American Heart Association (AHA) type IV-V and type VI carotid atherosclerotic lesions at multi-contrast black-blood MR images. Our results suggest that texture-based classification of type IV-V and type VI lesions is feasible on precontrast T1-weighted images. This preliminary evaluation indicates that carotid plaque texture analysis is a potentially useful adjunct tool for quantitative evaluation of atherosclerotic plaque vulnerability.

Xiaoming Bi¹, Zhaoyang Fan², Yutaka Natsuaki¹, Debiao Li², and Gerhard Laub^1
1Siemens Healthcare, Los Angeles, CA, United States, ²Cedars-Sinai Medical Center, Los Angeles, CA, United States

The recently developed MATCH technique integrates multiple 3D image sets into a single measurement and it is a promising method for carotid plaque characterization. One of the remaining challenges is the gross motion of carotid arteries that originates from pulsation, breathing and swallowing. In this work, a motion robust stack-of-stars sampling trajectory was implemented into the MATCH sequence (STAR-MATCH). Preliminary studies from volunteers and patient demonstrate it is feasible to characterize carotid plaque using the STAR-MATCH sequence with improve motion robustness.

Yibin Xie¹, Young-Jin Kim², Jianing Pang¹, Qi Yang¹, Jung-Sun Kim³, Christopher T. Nguyen¹, Zixin Deng¹, Byoung Wook Choi², Zhaoyang Fan¹, Daniel S. Berman¹, Hyuk-Jae Chang³, and Debiao Li^1
1Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea, Republic of, ³Division of Cardiology, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, Korea, Republic of

The aim of this work is to investigate the nature of pre-contrast and post-contrast T1w plaque hyper-intensity by comparing with coronary plaque morphology assessed by intracoronary optical coherence tomography (OCT). We scanned 13 healthy subjects and 30 stable angina patients using our recently developed whole-heart T1w coronary plaque characterization framework (CATCH). Compared with the classification based on OCT, we found that pre-contrast plaque to myocardial ratio (PMR) was significantly higher in the presence of large lipids, macrophages, and cholesterol crystals, whereas post-contrast PMR was significantly higher in the presence of macrophages and microvessels. 

Khaled Z. Abd-Elmoniem¹, Nadine Z. Ramos¹, Saami Yazdani², Ahmed M. Ghanem^1,3, Steven M. Holland⁴, Alexandra F. Freeman⁴, and Ahmed M Gharib^1
1Biomedical and Metabolic Imaging Branch, NIDDK, Bethesda, MD, United States, ²University of Southern Alabama, Mobile, AL, United States, ³Electrical Engineering, Suez Canal University, Ismailia, Egypt,⁴NIAID, Bethesda, MD, United States

In this study, coronary wall MRI is used to assess the coronary wall thickness of patients with autosomal dominant hyper-IgE (AD-HIES) or Job's syndrome; a primary immunodeficiency caused by mutations in STAT3. Supported by post-mortem histology, MRI coronary wall of AD-HIES patients was thicker than in healthy subjects but comparable to CAD patients. These findings suggest that coronary arteries in Job’s syndrome are affected with atherosclerosis, contrary to prior beliefs and study findings. Direct histologic evaluation confirms the presence of atherosclerosis with lack of needed supportive adventitial thickening and elastic components. These findings suggest mechanisms for weakened vessel wall that may lead to coronary dilation and aneurysm in AD-HIES.

Peter Opriessnig¹, Gunter Almer¹, Harald Froehlich¹, Claudia Cabella², Rudolf Stollberger³, Seth Hallstroem⁴, Gerd Hoerl⁴, and Harald Mangge^1
1Clinical Institute for Medical and Chemical Laboratory Diagnosis, Medical University of Graz, Graz, Austria, ²CRB Bracco Imaging SpA, Colleretto Giacosa, Torino, Italy, ³Institute of Medical Engineering, Graz University of Technology, Graz, Austria, ⁴Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria

Endothelial dysfunction plays a key role in the progression and pathogenesis of atherosclerosis (AS). DCE-MRI in combination with a special nitric oxide donor S-nitroso human serum albumin (S-NO-HAS) blood pool agent (B22956/1) compound could be an additional measure that provides information on the influence of plaque burden on the vascular permeability and vasomotion. In this work, we demonstrate the feasibility to investigate endothelial barrier function and NO induced endothelium-independent vasomotor response of the abdominal aorta in control and AS induced rabbits simultaneously. Relative vessel wall signal enhancement and change in lumen area were measured using a double-inversion-recovery turbo-spin-echo sequence.

Erin K Englund¹, Michael C Langham², Thomas F Floyd³, Felix W Wehrli², and Emile R Mohler^4
1Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States, ²Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, ³Department of Anesthesiology, Stony Brook University, Stony Brook, NY, United States, ⁴Department of Medicine, University of Pennsylvania, Philadelphia, PA, United States

Peripheral vascular function can be interrogated by measuring recovery dynamics following induced ischemia. In this study, 136 patients with peripheral artery disease were randomized into supervised exercise rehabilitation (SER) or standard medical care (SMC). Each patient’s leg was scanned before and after the intervention period. MRI data were acquired throughout an ischemia-reperfusion paradigm with PIVOT, a method to simultaneously and dynamically measure perfusion, venous oxygen saturation, and skeletal muscle T₂*. Patients randomized to SER had a significant increase in peak perfusion from baseline to follow-up when averaged across the entire cross-section of the leg and in the peroneus muscle. 

Trisha Roy^1,2, Garry Liu¹, Noor Shaikh¹, Kevan Anderson¹, Nicolas Yak¹, Xiuling Qi¹, Andrew Dueck^1,2, and Graham Wright^1,3
1Schulich Heart Program and the Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, ²Division of Vascular Surgery, University of Toronto, Toronto, Canada, ³Department of Medical Biophysics, University of Toronto, Toronto, Canada

Percutaneous vascular interventions (PVI) for treating peripheral arterial disease (PAD) have poor outcomes with high re-intervention and failure rates. Not all lesions are amenable to PVI, but predicting failure is difficult. While CT can identify heavily calcified lesions, current imaging offers limited differentiation between hard and soft PAD plaques, which impacts procedural success. This study demonstrates the feasibility of using MRI biomarkers to characterize plaque components in ex-vivo human peripheral arteries with histologic and microCT validation. We demonstrate that significantly higher puncture forces are required to cross non-calcified “hard” chronic total occlusions (CTOs) compared to “soft” CTOs, as classified by these MRI biomarkers.

Claudia Calcagno^1,2, Bram Coolen³, Bei Zhang^1,2, Gilles Boeykens ³, Philip Robson^1,2, Venkatesh Mani^1,2, Aart J Nederveen³, Willem Mulder^1,2, and Zahi Fayad^1,2
1Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, ²Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States, ³Department of Radiology, Academisch Medisch Centrum, Amsterdam, Netherlands

Accurate morphological measurements and classification of carotid plaques require imaging with high spatial resolution, and may benefit from the increased signal intrinsically available on ultra-high field (7T) magnets.  Several studies have already investigated carotid vessel wall imaging at 7T and compared it with state-of-the-art 3T protocols. These initial investigations have focused on 2 dimensional (2D), multi-slice imaging. Better than this approach, 3 dimensional (3D) vessel wall imaging allows characterizing extensive vascular territories while minimizing partial volume artifacts in plaque-prone regions, such as the carotid bulb and bifurcation. Here, we demonstrated the feasibility of performing 3D carotid vessel wall imaging on a whole body 7T clinical magnet using a custom made carotid coil.