Jae W Song¹, Athanasios Pavlou¹, Jiayu Xiao², Steven R Messe³, Scott E Kasner³, Zhaoyang Fan², and Laurie A Loevner^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Radiology, Cedars Sinai Medical Center, Los Angeles, CA, United States, ³Neurology, University of Pennsylvania, Philadelphia, PA, United States

Intracranial atherosclerosis is a common cause of ischemic stroke. Variability in protocol/pulse sequence design of intracranial vessel wall MR imaging (VWI) has led to different imaging endpoints to detect and characterize atherosclerosis. We systematically reviewed the literature to identify VWI investigations studying atherosclerosis to identify commonly reported imaging endpoints. The most common imaging endpoints using T1-weighting included wall enhancement, thickening, plaque quadrant in cross-section, and stenosis; on T2-weighting, intraplaque T2 signal intensity and wall thickening were common endpoints. Establishing diagnostically accurate imaging endpoints to validate as atherosclerosis biomarkers are critical to understand where efforts for technique optimization should be directed.

Liwen Wan¹, Na Zhang¹, Lei Zhang¹, Shi Su¹, Cheng Wang¹, Baochang Zhang¹, Hao Peng¹, Haoxiang Li¹, Dong Liang¹, Xin Liu¹, and Hairong Zheng^1
1Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China

Intracranial and extracranial atherosclerotic disease are major causes of ischemic stroke. Manual analyses of intracranial and extracranial artery vessel wall are time consuming and experience dependent. The purpose of this study was to develop an automated method to analyze 3D intra- and extracranial arterial vessel wall images, including vessel centerline tracking, vessel straightened reformation, vessel wall segmentation based on CNN, and morphological quantification. In conclusion, the proposed method facilitates the large-scale quantitative analysis of vessel wall, and is promising in promoting the clinical applications of MR vessel wall imaging.

Mariya Stanislavovna Pravdivtseva¹, Carson Hoffman², Leonardo A. Rivera-Rivera², Rafael Medero², Lindsay Bodart², Alejandro Roldan-Alzate², Michael A. Speidel², Charles M. Strother², Kevin M. Johnson², Oliver Wieben², Olav Jansen³, Naomi Larsen³, Philipp Berg⁴, Eva Peschke¹, and Jan-Bernd Hövener^1
1Neuroradiology and Radiology, Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein (UKSH), Kiel University, Kiel, Germany, ²Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA, Madison, WI, United States, ³Neuroradiology and Radiology, Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein (UKSH), Kiel, Germany, ⁴Research Campus STIMULATE, University of Magdeburg, Magdeburg, Germany, Magderburg, Germany

Intracranial aneurysm is a life-threatening disease. Vessel wall enhancement may be used as a marker to identify an aneurysm with a high risk of rupture. Accumulation of contrast agent in the vessel wall and slow or turbulent flow can contribute to the formation of vessel wall enhancement. In the current study enhanced signal on black blood MRI was observed in printed model of an intracranial aneurysm with and without Gd administration. The found signal was associated with the slow flow in the aneurysm. Additionally, the impact of spatial resolution, flow rate, MSDE preparation and contrast concentration was considered.

Qingle Kong^1,2,3, Haiqiang Qin⁴, Ning Wei⁵, Jing An⁶, Yan Zhuo^1,2,3, and Zihao Zhang^1,2,3
1State Key Laboratory of Brain and Cognitive Science, Beijing MR Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, ²University of Chinese Academy of Sciences, Beijing, China, ³CAS Center for Excellence in Brain Science and Intelligence Technology, Beijing, China, ⁴Department of neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China, ⁵China National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, China, ⁶Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China

Branch atheromatous disease (BAD) refers to small, deep brain infarcts that are predominantly caused by the occlusion of perforating arteries, which may lead to single subcortical infarction (SSI). However, there is no in-vivo radiological evidence of plaques in the perforating arteries due to their small caliber. In this study, we used high-resolution black-blood imaging at 7T to display the vessel wall of the anterior choroidal artery (AChA), and analyzed atherosclerotic plaques of AChA in patients with isolated infarcts on the posterior limb of internal capsule. The delineation of AChA plaques provides direct imaging evidence for the etiological diagnosis of BAD.

Jiayu Xiao¹, Shlee Song¹, Konrad Schlick¹, Shuang Xia², Tao Jiang³, Tong Han⁴, Robert Jackson¹, Oana Dumitrascu¹, Marcel Maya¹, Patrick Lyden¹, Debiao Li^1,5, Qi Yang⁶, and Zhaoyang Fan^1,5
1Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Tianjin First Central Hospital, Tianjin, China, ³Beijing Chaoyang Hospital, Beijing, China, ⁴Tianjin Huanhu Hospital, Tianjin, China, ⁵University of California, Los Angeles, Los Angeles, CA, United States, ⁶Beijing Xuanwu Hospital, Beijing, China

Ischemic stroke is a leading cause of disability and death, also has a high recurrence rate. Serial magnetic resonance vessel wall imaging (MR-VWI) was used to quantify the morphological changes of intracranial atherosclerotic plaque during the medical treatment of ischemic stroke patients. Changes of quantitative plaque features were compared between patients with different clinical outcomes. Our study showed an increasing trend in most progression patients. Maximum wall thickness, pre-contrast plaque-wall contrast ratio and post-contrast plaque enhancement ratio showed significant decreases in the non-progression group. Quantitative assessment of atherosclerotic lesion-specific responses to medical therapy is clinically feasible with serial MR-VWI.

Yan Gong¹, Chen Cao², Yu Guo³, Song Liu², Zhu Jinxia⁴, Shuang Xia³, Xiudi Lu³, Ying Zou³, and Wen Shen^3
1Tianjin Medical University NanKai Hospital, Tianjin, China, ²Department of Radiology, Tianjin Huanhu Hospital, Tianjin, China, ³Department of Radiology, Tianjin First Central Hospital, Tianjin, China, ⁴siemens-healthineers, Tianjin, China

  This study compared high-resolution vessel wall imaging (HR-VWI) and time-of-flight magnetic resonance angiography (TOF-MRA) for evaluation of stenosis using digital subtraction angiography (DSA) as the criterion standard. Compared with TOF-MRA, HR-VWI produced results that more closely agreed with DSA, showed better reproducibility and accuracy with smaller variance, and provided additional information on vessel wall pathology. HR-VWI may therefore be useful as an adjunct to DSA to diagnose stenosis and evaluate changes in intracranial vessel walls.

Yongjun Han^1,2, Runhua Zhang³, DanDan Yang^1,2, Hualu Han², Huiyu Qiao², Dongye Li⁴, Shuo Chen², Gaifen Liu³, and Xihai Zhao^2
1Center for Brain Disorders Research, Capital Medical University and Beijing Institute of Brain Disorders, Beijing, China, ²Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China, ³Department of Neurology, Beijing Tiantan Hospital, Capital Medical University; China National Clinical Research Center for Neurological Diseases, Beijing, China, ⁴Department of radiology, Sun Yat-sen Memorial hospital, Sun Yat-sen University, Beijing, China

This study investigated the association of vascular risk factors with asymptomatic and symptomatic ICAD using MR vascular wall imaging. Compared with controls, there was a positive association between hypertension and asymptomatic ICAD; and a positive association of hypertension, LDL, and diabetes and an inverse association of HDL with symptomatic ICAD (all p<0.05). Compared to asymptomatic ICAD, there was an inverse association between hyperlipidemia and symptomatic ICAD (p<0.001). We found that hypertension was a risk factor of asymptomatic ICAD and hypertension, diabetes and higher LDL were risk factors for symptomatic ICAD, whereas HDL was inversely associated with symptomatic ICAD.