Huimin Mao¹, Weiqiang Dou², Xinyi Wang¹, Kunjian Chen¹, and Yu Guo^1
1Radiology, The First Affiliated Hospital of Shandong First Medical University, Jinan, China, ²MR Research China, GE Healthcare, Beijing, China

This study aimed to use quantitative susceptibility mapping (QSM) to systematically investigate iron content changes of gray matter (GM) nuclei in patients with long-term anterior circulation artery stenosis (ACAS) and posterior circulation artery stenosis (PCAS). The differences of iron-related susceptibility in GM nuclei, including bilateral caudate nucleus, putamen (PU), globus pallidus (GP), thalamus, substantia nigra (SN), red nucleus and dentate nucleus (DN) were explored in 25 ACAS and 25 PCAS patients. Compared with healthy controls, mean susceptibility of bilateral PU, GP, and SN in ACAS and PCAS patients, and of extra bilateral DN in PCAS patients were significantly increased.

Jack Echols¹, Soham Shah¹, and Frederick Epstein^1
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States

Epicardial adipose tissue (EAT) fatty acid composition (FAC) plays an important role in coronary vascular inflammation due to obesity and diabetes. We show for the first time the feasibility of quantifying human EAT FAC using radial multi-echo gradient-echo MRI with IDEAL mapping. This method may enable further investigations into the relationship between EAT fatty acid composition and cardiovascular disease.

Huimin Mao¹, Weiqiang Dou², Xinyi Wang¹, Kunjian Chen¹, and Yu Guo^1
1Radiology, The First Affiliated Hospital of Shandong First Medical University, Jinan, China, ²MR Research China, GE Healthcare, Beijing, China

The main purpose was to quantitatively evaluate iron alterations in gray matter (GM) nucleus of patients with unilateral middle cerebral artery stenosis (MCAS)-related ischemic stroke using quantitative susceptibility mapping (QSM). Forty-six unilateral MCAS patients and thirty-eight healthy controls underwent QSM examination. Iron-related susceptibility of GM nucleus, including bilateral caudate nucleus, putamen (PU), globus pallidus (GP), thalamus, substantia nigra (SN), red nucleus, and dentate nucleus were assessed. Compared with healthy controls, PU, GP, and SN regions at lesion side presented significantly increased susceptibility in patients, indicating that abnormal iron metabolism may present in the brain after ischemic stroke.

Mohamed Kassem^1,2, Ellen Eline Boswijk^1,2, Jochem van der Pol^1,2, Rik PM Moonen², Jan Bucerius³, Werner H Mess⁴, Robert Jan van Oostenbrugge^1,5, Zhaoyang Fan⁶, and M Eline Kooi^1,2
1CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, Netherlands, Maastricht, Netherlands, ²Department of Radiology and Nuclear Medicine, Maastricht University medical center (MUMC+), Maastricht, Netherlands, ³Department of Nuclear Medicine, Georg-August University Göttingen, Gottingen, Germany, ⁴Department of Clinical Neurophysiology, Maastricht University medical center (MUMC+), maastricht, Netherlands, ⁵Department of Neurology, Maastricht University Medical Center+ (MUMC+), maastricht, Netherlands, ⁶Department of Radiology, University of Southern California, Los Angeles, CA, United States

Multi-contrast Atherosclerosis Characterization (MATCH) was developed to quantify of carotid atherosclerotic plaque composition within 5 minutes’ scan time. Twenty symptomatic patients with ≥2 mm carotid plaque underwent 3.0 Tesla conventional multi-sequence and MATCH MRI. Excellent agreement was obtained for scoring a Lipid-rich necrotic core (LRNC) intraplaque hemorrhage (IPH) on the MATCH images while fair for calcifications. No significant differences between MATCH and multi-sequence MRI were found in volume of LRNC, IPH and calcifications. We demonstrated excellent agreement between MATCH and multi-sequence MRI for the identification and quantification of LRNC and IPH within significant shorter time. 

Mohamed Kassem^1,2, Tahnee Gorissen¹, Mohamed AlBenwan¹, Dianne van Dam-Nolen³, Madieke I Liem⁴, Rob J van der Geest⁵, Jeroen Hendrikse⁶, Werner H Werner Mess^1,7, Paul J Nederkoorn⁴, Daniel Bos^3,8, Patty Nelemans⁹, Robert Jan van Oostenbrugge^1,10, and M Eline Kooi^1,2
1CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, Netherlands, Maastricht, Netherlands, ²Department of Radiology and Nuclear Medicine, Maastricht University medical center (MUMC+), maastricht, Netherlands, ³Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands, ⁴Department of Neurology, Amsterdam UMC, location AMC, Amsterdam, Amsterdam, Netherlands, ⁵Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, ⁶Radiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, ⁷Department of Clinical Neurophysiology, Maastricht University Medical Center+ (MUMC+), maastricht, Netherlands, ⁸Epidemiology, Erasmus MC, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands, ⁹Department of Epidemiology, Maastricht University, Maastricht, The Netherlands, maastricht, Netherlands, ¹⁰Department of Neurology, Maastricht University Medical Centre, maastricht, Netherlands

The factors that contribute to intraplaque hemorrhage (IPH) development within the carotid atherosclerotic plaque are incompletely understood. Previously, we demonstrated that IPH is associated with a thin/ruptured fibrous cap (TRFC) and disruption of the plaque surface on in a cross-sectional study. Baseline and 2 year’s follow-up carotid MR images of 110 patients from the Plaque at Risk (PARISK) study were analyzed. IPH volume change in TRFC at baseline was significant different (p=0.04) than thick fibrous cap group. Baseline IPH volumes are larger in patients with TRFC and disrupted plaque surface, but didn’t increase during the follow-up. 

Sean Gullette¹, Stephen Andrews², Courtney Whalen², Floyd J. Mattie², Ximing Ge², Catharine Ross², Rita Castro^2,3,4, and Thomas Neuberger^1,5
1Huck Institutes of The Life Sciences, The Pennsylvania State University, State College, PA, United States, ²Department of Nutritional Sciences, The Pennsylvania State University, State College, PA, United States, ³Research Institute for Medicines (iMed.ULisboa), Universidade de Lisboa, Portugal, Lisboa, Portugal, ⁴Department of Pharmaceutical Sciences and Medicines, Universidade de Lisboa, Portugal, Lisboa, Portugal, ⁵Department of Biomedical Engineering, The Pennsylvania State University, State College, PA, United States

Currently, histological methods of plaque analysis in aortas from murine models of atherosclerosis do not allow for a holistic view of the vascular lesions. Using high-field MRI, plaque volume in Apoe^-/- mice can be analyzed, and when compared to traditional histology, has a higher throughput and is non-destructive. Using a 3D gradient echo sequence at 14 tesla, high-resolution images of the aortas were achieved. The images were segmented and quantified providing a 3-dimensional view of plaque distribution and volume. Overall, using a high-field MRI system allowed for a detailed and complete view of vascular components.

Junmin Liu¹, Omer Oran², and Maria Drangova^1,3
1Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada, ²Siemens Healthcare Canada, Oakville, ON, Canada, ³Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada

By adding long TEs to the Dixon acquisition, the chemical-shift-based T2*-weighted multi-echo GRE (CS-T2*-mGRE) techniques have gained attention, because they are able to generate co-registered multi-contrast images and quantitative maps. However, flow-suppressed CS-T2*-mGRE sequences have not been evaluated for carotid wall imaging. We compared the performance of simultaneous quantification of fat fraction (FF) and R2* from CS-T2*-mGRE sequences with and without saturation slabs, and with the incorporation of DANTE pulses for black blood imaging (DANTE-CS-T2*-mGRE); we used the FF for fat-suppression to better visualize the vessel wall from DANTE-CS-T2*-mGRE as well as the carotid artery lumen from CS-T2*-mGRE.

Meng Lu¹, Hui Han¹, Debiao Li^2,3, and Yibin Xie^1
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Cedars-Sinai Medical Center, Los Angeles, CA, United States, ³Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States

Plaque to Myocardium Ratio (PMR) based on T1-weighted MRI is an important quantitative biomarker to classify high-risk coronary plaque. However, it is calculated based on relative signal intensities, therefore, sensitive to variations in physiological and acquisition conditions. In this work, Bloch simulations were performed to explore the impact of heart rate, echo spacing, flip angle, and the number of readout segments on PMR. A computational model was further proposed to effectively reduce the acquisition-related PMR variations demonstrated in simulations and in vivo studies. The proposed method may potentially improve the precision of PMR and facilitate its comparison in longitudinal studies.

Jin Zhang¹, Beibei Sun², Shenghao Ding², Jiaqi Tian², Jieqing Wan², Jilei Zhang³, Weibo Chen³, Xihai Zhao⁴, Yuan Chun⁵, Jianrong Xu², and Huilin Zhao^2
1Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China, ²Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China, ³Philips Healthcare, Shanghai, China, ⁴Biomedical Engineering & Center for Biomedical Imaging Research, Tsinghua University, Beijing, China, ⁵University of Washington, Seattle, WA, United States

Cervical artery dissection (CAD) is one of the important causes of ischemic stroke in young and middle-aged people[1; 2]. DSA remains the gold standard for identifying and characterizing carotid vascular dissections[3]. However, this imaging approach is known to have certain limitations, including invasiveness, ionizing radiation exposure, uneconomic, and inconvenience in follow-up. Recently, rapid three-dimensional MR vessel wall imaging (3D MR-VWI) techniques have been developed to visualize arterial lumen and outer wall boundaries non-invasively and without contrast administration. Non-invasive 3D MR-VWI has the potential to be a powerful tool for follow-up of cervical artery dissection.

Russell W. Chan^1,2, Yixi Xue¹, Ji Won Bang¹, Muneeb A. Faiq¹, Thajunnisa A. Sajitha¹, Royce P. Lee¹, Peiying Liu³, Christopher K. Leung⁴, Gadi Wollstein¹, Joel S. Schuman¹, and Kevin C. Chan^1,5
1Department of Ophthalmology, New York University Grossman School of Medicine, New York, NY, United States, ²Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States, ³Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States, ⁴Department of Ophthalmology, The University of Hong Kong, Hong Kong, Hong Kong, ⁵Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States

Recently, we used a novel resting-state fMRI method to map relative cerebrovascular reactivity (rCVR) without gas challenge, and demonstrated decreased rCVR in the visual cortex and increased rCVR in the basal forebrain in glaucoma patients relative to healthy subjects. However, the underlying mechanisms remain unclear. Here, we applied a hydrogel-induced glaucoma mouse model to chronically elevate intraocular pressure, mapped rCVR using resting-state fMRI, and measured optomotor responses. Our results showed similar patterns of rCVR changes along with visual impairments, indicating a role of chronic intraocular pressure elevation on the widespread vascular and functional brain changes in experimental glaucoma.