Rui Shen¹, Hualu Han¹, Jinmei Zheng², Huiyu Qiao¹, Zihan Ning¹, Xinyu Tong³, Yunjing Xue⁴, and Xihai Zhao^1
1Center for Biomedical Imaging Research, Tsinghua University, Beijing, China, ²Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China, ³Department of Biomedical Engineering, School of Life and Science, Beijing Institute of Technology, Beijing, China, ⁴Department of Radiology, Fujian Medical University Union Hospital, Fuzhou, Fujian, China

This study investigated the relationship between the geometry of vertebra-basilar system and hemodynamic measurements and presence of BA plaques. We found that geometric measurements and most hemodynamic features were significantly correlated with the occurrence of BA plaque (mean curvature, r=0.368; NOR-TAWSS-NF, r=-0.312; SAR-OSI-NF, r=0.290; NOR-TAWSS-nNF, r=-0.387; NOR-OSI-nNF, r=0.440). There were significant differences in mean curvature, hemodynamic characteristics of Newtonian flow and non-Newtonian flow models between patients with and without BA plaque. Our study indicated that geometric features and non-Newtonian flow model-based hemodynamic measurements are risk factors of BA plaque.

Yiran Zhou¹, Guiling Zhang¹, Wenzhen Zhu¹, and Weiyin Vivian Liu^2
1Tongji Hospital affiliated to Tongji Medical College of Huazhong University of Science & Technology, Wuhan, China, ²GE Healthcare, Beijing, China

To develop a nomogram for accurate prediction of acute ischemic stroke (AIS) outcome, 522 AIS patients were retrospectively selected in this study. Radiomics features were extracted from DWI and ADC maps and radiomics score was established. Logistic regression analysis was implemented to sift independent clinical factors and construct prediction model. Finally, the nomogram incorporated age, sex, stroke history, diabetes, baseline modified Rankin Scale, baseline National Institutes of Health Stroke Scale score and radiomics score yield the great predictive performance with an AUC-ROC of 0.868 in training cohort and 0.890 in validation cohort, the AUC-PR reached 0.733 and 0.787 respectively.

Yuelei Lyu¹, Shuna Yang¹, Chen Zhang², Qinglei Shi², Guang Yang³, Wenli Hu¹, and Qi Yang^1
1Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China, ²MR Scientific Marketing, Siemens Healthineers, Beijing, China, ³Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai, China

This study used DKI to investigate possible microstructural alterations of brain tissues associated with plenty of EPVS in the basal ganglia (BG) in patients of SVD. Our preliminary results revealed that patients with EPVS in the BG showed significant reductions in kurtosis parameters from DKI and elevated diffusion parameters derived from DKI in bilateral putamen. We also found abnormal diffusion parameters in mainly bilateral BG, limbic system, temporal lobe,and other scatter brain regions. Our data suggests patients with plenty of EPVS in the BG might undergo microstructure impairments in the regions above, especially bilateral insular and BG. 
 

Miaoxin Yu¹, Yanan Jia², Dandan Yang³, Runhua Zhang¹, Yong Jiang¹, Guitao Zhang¹, Huiyu Qiao⁴, Hualu Han⁴, Rui Shen⁴, Zihan Ning⁴, Xihai Zhao⁴, and Gaifen Liu^1
1Department of Neurology, Beijing Tiantan Hospital, Capital Medical University; China National Clinical Research Center for Neurological Diseases, Beijing, China, ²Department of Neurology, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei, China, ³Department of Radiology, Beijing Geriatric Hospital, Beijing, China, ⁴Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China

In this cross-sectional, observational study, we investigated the association between antiplatelet therapy and cerebral microbleeds (CMBs) in community-based participants without stroke. The presence, count, and location of CMBs were evaluated by susceptibility weighted imaging. Antiplatelet therapy included aspirin use alone, clopidogrel use alone, cilostazol use alone, and dual antiplatelet therapy with aspirin and clopidogrel. We found that antiplatelet therapy was independently associated with CMBs at any location, particularly lobar CMBs, and aspirin use was a risk factor for any CMB and lobar CMBs. Our study suggests that optimizing antiplatelet treatment strategies in stroke-free population may decrease the risk of CMBs.

Mengmeng Feng¹, Hongwei Wen^2,3, Haotian Xin¹, Changhu Liang⁴, and Lingfei Guo^4
1Shandong Provincial Hospital, Jinan, China, ²Key Laboratory of Cognition and Personality (Ministry of Education), Chongqing, China, ³Southwest University, Chongqing, China, ⁴Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China

Cerebral small vessel disease (CSVD) patients can present structural and functional abnormalities. We divided 102 subjects into three groups and obtained information about altered spontaneous brain activity using amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF) and regional homogeneity (ReHo) methods based on resting-state functional MRI. Compared with controls and the CSVD without cerebral microbleeds (CSVD-n) group, the CSVD with cerebral microbleeds (CSVD-c) group showed significantly increased ALFF/ReHo values and decreased fALFF values in some brain regions, which are correlated to abnormal clinical characteristics. These results expounded the underlying neurophysiological mechanisms in CSVD patients.

Di Wu¹, Shun Zhang², Weiyin Vivian Liu³, and Wenzhen Zhu^4
1Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China, ²Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China, ³GE Healthcare, Beijing, China, Beijing, China, ⁴Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China

 The study aimed to assess the correlation of arterial transit artifact (ATA) with clinical outcomes and collateral circulation status in stroke patients beyond 24 hours from last known well. ATA is assessed by 3-dimentional pseudo-continuous ASL (3D-pCASL), collateral status by magnetic resonance angiography (MRA) using a grading system from 0 to 3, and clinical outcomes by 3-month modified Ranking Scale (3m-mRS). ATA was present in about half of the enrolled patients, most of whom had large artery disease. Though the correlation between ATA and the degree of collateral supply was not statistically significant, ATA could predict the favorable clinical outcomes.

Ling Li¹, XiaoLing Zhang¹, Xiaoyan Lei¹, Min Tang¹, Xuejiao Yan¹, and Kai Ai^2
1Department of MRI, Shaanxi Provincial People's Hospital, Xi'an, China, ²Philips Healthcare, Xi'an, China

This study used high-resolution magnetic resonance imaging (HRMRI) to explore plaque characteristics of young adults with symptomatic intracranial atherosclerotic stenosis (sICAS). Compared with old patients, young patients with sICAS have a smaller Maximum wall thickness and a greater ability to reconstruct, and are more prone to positive remodeling, which may cover up some patients with atherosclerotic stenosis. The results show great clinical importance for a better understanding of youth intracranial arterial plaque features and highlights the importance of HRMRI.

Haining Wei¹, Fang Wu², Jie Lu², and Rui Li^1
1Tsinghua University, Beijing, China, ²Xuanwu Hospital, Capital Medical University, Beijing, China

Intracranial atherosclerotic disease (ICAD) is one of the main causes of ischemic stroke. Increasing evidence supports that vulnerable plaque is correlated with risk for stroke, which reveals the importance of intracranial plaque risk identification. Radiomics is an automated and repeatable approach for extracting massive features for medical imaging. However, few articles have focused on radiomic-based studies of intracranial plaque of basilar artery and middle cerebral artery. In this study, we propose to build a high-risk intracranial plaque model using radiomics features and machine learning to differentiate symptomatic plaque from asymptomatic plaque, which is helpful in guiding clinical management.

Yingchao Tan^1,2,3, Qiaoyan Chen^1,2, Qian Zou³, Yanling Chen³, Junyu Chen³, Xin Liu^1,2, Hairong Zheng^1,2, and Ye Li^1,2
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, ²Key Laboratory for Magnetic Resonance and Multimodality Imaging of Guangdong Province, Shenzhen, China, ³Shanghai United Imaging Healthcare, Shanghai, China

MR vessel wall imaging of intracranial and carotid arteries is still challenging because of the small cross-sectional size of the vessel wall and the cord, and susceptibility effects, especially in the carotid and the spinal cord. In this study, a 72-channel coil system that consists of a 64-channel head coil combined with an 8-channel carotid coil was proposed and characterized in its performance by comparison with a 40-channel coil system. As a result, the proposed 72-channel coil system provides improved performance in SNR, parallel imaging capability, and image quality.

Chenlin Du¹, Zihan Ning¹, Huiyu Qiao¹, Shuo Chen¹, Tao Wang², Jingli Cao³, Huo Ran⁴, Dongye Li⁵, Chunjiang Hu¹, Shuwan Yu¹, Hualu Han¹, Rui Shen¹, Dandan Yang^1,6,7, Cancheng Liu⁸, Peng Wu⁹, and Xihai Zhao^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China, ²Department of Neurosurgery, Peking University Third Hospital, Beijing, China, ³China National Clinical Research Center for Neurological Disease, Beijing Tiantan Hospital, Capital Medical University, Beijing, China, ⁴Department of Radiology, Peking University Third Hospital, Beijing, China, ⁵Department of Radiology, Sun Yat-Sen Memorial hospital, Sun Yat-Sen University, Guangzhou, China, ⁶Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China, ⁷Department of Radiology, Beijing Geriatric Hospital, Beijing, China, ⁸Thorough Images, Beijing, China, ⁹Philips Healthcare, Shanghai, China

This study investigated the accuracy of 3D multi-contrast MR vessel wall imaging (VWI) in characterizing carotid vulnerable plaque compositions including lipid-rich necrotic core (LRNC), intraplaque hemorrhage (IPH) and calcification (CA) validated by histology. Good agreements were found between MR and histology in identifying LRNC (κ=0.67), IPH (κ=0.66), and CA (κ=0.62) after excluding histological sections with the plaque components <1.77 mm². Moderate agreements were reached in quantifying plaque compositions with r values ranged from 0.46 to 0.61 (LRNC: r=0.52; IPH: r=0.6; CA: r=0.46). Our study demonstrated that 3D multi-contrast MR VWI is capable of accurately characterizing carotid vulnerable atherosclerotic plaques.

Huiyu Qiao¹, Qiansu Yang², Shuo Chen¹, Zihan Ning¹, Hualu Han¹, Rui Shen¹, Peng Wu³, Huijun Chen¹, and Xihai Zhao^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine Tsinghua University, Beijing, China, ²Center of Medicine Clinical Research, Department of Pharmacy, Medical Supplies Center of PLA General Hospital, Beijing, China, ³Philips Healthcare, Shanghai, China

MR T1-, T2-, and T2*- mapping have been used to characterize carotid plaques. In this study, we realized a 3D Large-Coverage (longitudinal coverage: 160 mm) Simultaneous QUantitative T1-T2-T2* Mapping (LC-SQUMA) sequence with 0.8 mm isotropic spatial resolution. The LC-SQUMA sequence showed excellent agreements with reference imaging in measuring T1 (R²=0.96), T2 (R²=0.85) and T2* (R²=0.90) values. No significant difference was found in measuring T1, T2 and T2* values (all P>0.05) of cervical muscle between LC-SQUMA sequence and clinical referenced quantitative imaging sequences. The 3D LC-SQUMA sequence is feasible in the large-coverage carotid vessel wall quantitative imaging with isotropic spatial resolution.

Xiaoyan Bai¹, Qingle Kong², Zhiye Li¹, Pingping Fan¹, and Binbin Sui^3
1Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing Neurosurgical Institute, Beijing, China, Beijing, China, ²MR Collaboration, Siemens Healthineers Ltd., Beijing, China, Beijing, China, ³Tiantan Neuroimaging Center of Excellence, China National Clinical Research Center for Neurological Diseases, Beijing, China, Beijing, China

A total of 40 MCA atherosclerotic plaques of 34 patients (20 symptomatic and 20 asymptomatic plaques) were quantitatively analyzed of plaque features including plaque burden, length, remodeling index, plaque distribution, and surface morphology using 7T vessel wall Magnetic Resonance Imaging (VW-MRI). Compared with the asymptomatic plaques, symptomatic MCA plaques had larger plaque length and higher plaque burden. Superior-wall distribution and irregular plaque surface were observed more commonly on the symptomatic MCA plaques. 7T VW-MRI is a promising method to evaluate the atherosclerotic plaque features at MCAs.

Sen Jia¹, Jing Cheng¹, Zhuoxu Cui², Lei Zhang¹, Haifeng Wang¹, Xin Liu¹, Hairong Zheng¹, Hongying Zhang³, and Dong Liang^1,2
1Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Shenzhen, China, ²Research Center for Medical AI, Shenzhen Institutes of Advanced Technology, Shenzhen, China, ³Northern Jiangsu People's Hospital, Yangzhou, China

Deep learning regularized SPIRiT reconstruction is developed by unrolling the conventional L1-SPIRiT optimization solved by the projection onto convex sets (POCS) iteration into a multi-layer convolutional neural network. The learnable network regularization with 3D convolution improved the reconstruction accuracy and efficiency compared with the iterative L1-SPIRiT with 2D sparsity regularization in a fixed transform domain. The simplicity of POCS iteration also benefits the design complexity of the DL-SPIRiT network. The proposed DL-SPIRiT could accelerate the joint intracranial and carotid vessel wall imaging of isotropic 0.6 mm resolution by 8-fold, leading to a scan time of only 3.5 minutes.

Dushyant Kumar¹, Rajesh Mishra¹, Chahat Kumar², Priyanka Bhagat², Padma Srivastava², and Rama Jayasundar^1
1NMR, All India Institute of Medical Sciences, Delhi, India, ²Neurology, All India Institute of Medical Sciences, Delhi, India

This study has compared using fMRI, the changes effected by physiotherapy and yoga in post-stroke recovery. Ischemic stroke patients (n=20) with motor deficits were divided into two groups - yoga and physiotherapy. Each group practiced yoga or physiotherapy for one hour daily for six months, under the supervision of certified yoga trainers and physiotherapists, respectively. Pre- and post- (6 months)  intervention evaluations were carried out using fMRI at 3T and NIHSS scores. Results show significant improvement in the NIHSS scores and BOLD activity in the affected sensory motor region of the stroke patients in the yoga group compared to physiotherapy. 

Shujing Ren¹, Wei Wu², Chunqiu Su¹, Qianmiao Zhu², Michaela Schmidt³, Yi Sun⁴, Christoph Forman³, Peter Speier³, Xunning Hong¹, and Shanshan Lu^1
1Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China, ²Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China, ³Siemens Healthcare, Erlangen, Germany, ⁴Siemens Healthcare, Shanghai, China

It is important for MMD patients to receive repeated life-time follow-up examinations for evaluation of bypass patency and collateral formation from neovascularization after bypass surgery. In this study we evaluated the clinical value of high-resolution (0.4 × 0.4 × 0.4 mm³ isotropic) CS TOF-MRA for assessment of STA-MCA bypass and neovascularization by using CTA as the reference. We found that high-resolution CS TOF-MRA could provide better visualization for both STA-MCA bypass and neovascularization than traditional CTA within a clinically reasonable time in MMD patients after surgical revascularization.

Chao Xia^1,2, Jiaxin Zeng^1,2, Xia Wei^1,2, Ziyu Li^1,2, Yuan Sun^1,2, Na Hu^1,2, Yi Liu³, Kai Ai⁴, and Su Lui^1,2
1Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, Department of Radiology, West China Hospital, Sichuan University, Chengdu, China, ²Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, China, ³Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, China, ⁴Philips Healthcare, Xi'an, China

The amide proton transfer weighted (APTw) imaging was used to investigate the collateral circulation change and pH alteration in patients with moyamoya disease (MMD). Thirteen patients underwent computed tomography perfusion (CTP), digital subtraction angiography (DSA), and APTw imaging. We analyzed the difference in APTw values between the cerebral and cerebellar hemispheres. Then subgroup analysis was conducted according to the stage of preinfarction period based on CTP. The results revealed that APTw values were significantly lower in cerebral hemispheres than those in cerebellar hemispheres. However, no significant difference in APTw values among patients with different stages of preinfarction period was found.

Yu-Chen Chuang^1,2, Wen-Chau Wu^1,3, Vincent Chin-Hung Chen^4,5, Yen-Hsuan Hsu⁶, and Jun-Cheng Weng^2,5,7
1Institute of Medical Device and Imaging, Graduate Institute of Clinical Medicine, National Taiwan University, Taipei city, Taiwan, ²Department of Medical Imaging and Radiological Sciences, Graduate Institute of Artificial Intelligence, Chang Gung University, Taoyuan, Taiwan, ³Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan, ⁴School of Medicine, Chang Gung University, Taoyuan, Taiwan, ⁵Department of Psychiatry, Chang Gung Memorial Hospital, Chiayi, Taiwan, ⁶Department of Psychology, National Chung Cheng University, Chiayi, Taiwan, ⁷Medical Imaging Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan

Although understanding of the relationship between cardiovascular disease and brain dysfunction has improved significantly over the past decades, it remains unclear whether hypertension can be a potential risk factor for cognitive impairment. This study tried to use resting-state fMRI to explore the association between hypertensive (HTN) and brain function alterations. We found significant differences in the DMN subsystems in HTN group compared with control group. We also observed higher assortativity in HTN group.