Hui Wang¹, Xianchang Zhang², Quanzhi Feng¹, Yutian Li¹, Jinli Li¹, Yujun Wang³, Guangzhao Yang³, Qingle Kong², Zihao Zhang⁴, and Tong Han^1
1Radiology, Tianjin Huanhu Hospital, Tianjin, China, ²MR Collaboration, Siemens Healthcare Lid., Beijing, China, ³Radiology, Tongde Hospital of Zhejiang Province, Hangzhou, China, ⁴State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China

This study evaluated the association between plaque existence and lenticulostriate artery (LSA) morphology using high-resolution vessel wall imaging (HR-VWI) in patients with lenticulostriate infarction and non-stenotic middle cerebral artery (MCA). Patients were divided into plaque and non-plaque groups based on the plaque presence in the MCA-M1 segment of the infarcted hemisphere. Atheromatous plaque was found in 52.8% of patients, and the laterality index of the LSA and total length were higher in the plaque group. These findings suggest that HR-VWI may help distinguish branch from non-branch atheromatous small vessel disease.

Shanmukha Srinivas¹, Tara Retson¹, Aaron Simon², Marc Alley³, Shreyas Vasanawala³, Jona Hattangadi-Gluth², Albert Hsiao¹, and Nikdokht Farid^1
1Department of Radiology, University of California San Diego, San Diego, CA, United States, ²Department of Radiation Medicine and Applied Sciences, University of California San Diego, San Diego, CA, United States, ³Department of Radiology, Stanford University, Stanford, CA, United States

This study evaluated the use of 4D flow MRI to assess hemodynamic changes to cerebral arteriovenous malformations after stereotactic radiosurgery (SRS). As a comparison, structural changes of AVMs were measured on T₂W single shot fast spin echo (SSFSE) and time-of-flight (TOF) angiography. Hemodynamic changes, including reduction in feeding arterial flow and draining venous flow, preceded structural changes including arterial circumference and nidus volume for large arteriovenous malformations. This study demonstrated the potential utility of 4D flow MRI as a robust tool to supplement existing imaging techniques and measure early treatment response after stereotactic radiosurgery (SRS).

Tamás I. Józsa¹, Jan Petr², Alle Meije Wink³, Frederik Barkhof³, Henk J. M. M. Mutsaerts³, and Stephen J. Payne^1
1Department of Engineering Science, University of Oxford, Oxford, United Kingdom, ²Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany, ³Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, Amsterdam, Netherlands

Human brain perfusion simulations have been limited to less than five patient-specific cases. We propose a pipeline based on MRI to overcome this limitation. Computational geometry is adjusted using T1-weighted MRI, and the perfusion model parameters are tuned based on arterial spin labeling perfusion MRI. A cohort of 75 patients is used to demonstrate that the pipeline is suitable to generate virtual patients with statistically accurate and precise cerebral blood flow maps. Our findings encourage future studies on in silico clinical trials using similar virtual cohorts to improve ischaemic stroke interventions.

Cecilia Björnfot¹, Anders Garpebring¹, Sara Qvarlander¹, Jan Malm², Anders Eklund¹, and Anders Wåhlin^1,3
1Department of Radiation Sciences, Umeå University, Umeå, Sweden, ²Department of Clinical Sciences, Umeå University, Umeå, Sweden, ³Umeå Center for Functional Brain Imaging, Umeå University, Umeå, Sweden

Age-related arterial wall hardening could be detrimental to brain function via several pathways. A consequence of vessel wall hardening is the increased velocity at which the cardiac-induced pulse wave travels. Previously, pulse wave velocity in the aorta and extracranial arteries have been linked to brain pathology. However, there's a lack of  “target-organ” measurements. Here we present a 4D flow MRI method to estimate pulse wave velocity in the cerebral arterial tree. The method is shown to be stable in an internal consistency test, and of sufficient sensitivity to robustly detect age-related increases in intracranial pulse wave velocity.

Piotr Radojewski¹, Arun Joseph^2,3,4, Gabriele Bonnano^2,3,4, Tom Hilbert^5,6,7, Tobias Kober^5,7,8, Jan Gralla¹, Roland Wiest¹, and Pasquale Mordasini^1
1Institute of Diagnostic and Interventional Neuroradiology, Bern University Hospital, Inselspital,, Bern, Switzerland, ²2. Advanced Clinical Imaging Technology, Siemens Healthcare AG, Bern, Switzerland, ³3. Translational Imaging Center, Sitem-Insel, Bern, Switzerland, ⁴4. Departments of Radiology and Biomedical Research, University of Bern, Bern, Switzerland, ⁵5. Advanced Clinical Imaging Technology, Siemens Healthcare AG, Lausanne, Switzerland, ⁶6. Department of Radiology, , Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland, ⁷7. LTS5, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland, ⁸6. Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland

MRI-based vessel imaging has two goals, the anatomico-morphological depiction and vessel wall imaging, including delineation of contrast enhancement within the vessel wall. We performed sequence implementation and optimization in healthy volunteers to establish a dedicated 7T MRI protocol for vessel imaging at 7T. We implemented MPRAGE, T2 TSE, SWI, and ToF for anatomico-morphological vessel-delineation and optimized T1 SPACE and T1 SE for vessel wall delineation.

Jackson Moore¹, Maria Aristova¹, Ramez Abdalla¹, Ann Ragin¹, Eric Russell¹, Fan Caprio², Michael Hurley¹, Susanne Schnell³, Sameer A. Ansari¹, and Michael Markl^1
1Radiology, Northwestern University, Chicago, IL, United States, ²Neurology, Northwestern University, Chicago, IL, United States, ³Universitaet Greifswald, Greifswald, Germany

Intracranial atherosclerotic disease (ICAD) is a known risk factor for ischemic stroke. There is a need to develop quantitative imaging biomarkers to identify patients who may not respond to medical management. Here, the pulsatility index (PI) and resistivity index (RI) are derived from 4D flow MRI using a semi-automated vessel identification and segmentation workflow for 7 subjects with severe ICAD. Initial results show significant asymmetries (PI: 0.89 ± 0.2 vs 1.06 ± 0.1, p = 0.04; RI: 0.92 ± 0.1 vs 1.03 ± 0.07, p = 0.009) for affected vessels as well as contralateral hemisphere changes compared to controls.

Niranjan Balu¹, Wenjin Liu¹, Zhensen Chen¹, Anders Gould¹, Dan S Hippe¹, Li Chen¹, Binbin Sui², Mi Shen², Peiyi Gao², Thomas S Hatsukami¹, and Chun Yuan^1
1Radiology, University of Washington, Seattle, WA, United States, ²Beijing Tiantan Hospital, Beijing, China

Distal intracranial artery length measurement on TOF-MRA is a biomarker of age-related vascular changes but its measurement reproducibility in multi-center setting is unknown. We studied the dependence of measurement reproducibility on protocol and scanner platform variation. Reproducibility increased with increasing superior-inferior TOF-MRA coverage and consistency of imaging parameters. After correcting for these factors, high reproducibility was achieved between Philips 3T and Siemens 3T scanner platforms suggesting feasibility of quantitative intracranial vessel length measurements for multi-platform serial MRI studies.

Ling Li¹, Xiao Ling Zhang¹, Min Tang¹, Xue jiao Yan¹, Nian E Ma¹, Xiao Yan Lei¹, Xin Zhang¹, Juan Li¹, and Kai Ai^2
1Department of MRI, Shaanxi Provincial People's Hospital, Xi'an, China, ²Philips Healthcare, Xi'an, China

The aim of this study was to investigate plaque characteristics and clinical risk factors of intracranial atherosclerotic stroke in young adults. The vessel wall characteristics of plaque and clinical data were compared between young and old patients. Our results showed that maximum vessel wall thickness, narrowest vascular area and vessel wall area of young patients were significantly lower than those of old patients, while the number of young patients with plaque positive remodeling was higher. In addition, the number of young people suffering from hyperhomocysteinemia was significantly higher than that of old patients, while suffering from hypertension was significantly lower.

Adam E. Goldman-Yassen¹, Eytan Raz², Anna Derman², Ahrya Derakhshani³, and Seena Dehkharghani^2,4
1Department of Radiology, Children's Healthcare of Atlanta, Atlanta, GA, United States, ²Department of Radiology, New York University Langone Medical Center, New York, NY, United States, ³Department of Radiology, UCLA Health, Los Angeles, CA, United States, ⁴Department of Neurology, New York University Langone Medical Center, New York, NY, United States

High-resolution black-blood vessel wall imaging optimized with robust flow suppression offers reproducible, reliable, and non-invasive longitudinal evaluation of flow diversion treated aneurysms, with superior overall classification accuracy relative to conventional TOF or dynamic MRA. Aneurysm and parent vessel enhancement may persist even after angiographic occlusion during the healing phase of obliterated aneurysm.

Isil Unal¹, Duygu Dengiz², Eckhard Quandt², Mona Salehi Ravesh¹, Jan-Bernd Hövener³, Mariya Pravdivtseva¹, and Olav Jansen^1
1Department for Radiology and Neuroradiology, University Hospital Schleswig-Holstein, Campus Kiel, Germany, Kiel, Germany, ²Institute for Materials Science, Faculty of Engineering, University of Kiel, Germany., Kiel, Germany, ³Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Kiel, Germany

Blood flow , which is one of the factors leading to aneurysm rupture, can be measured in vivo by 4D flow MRI. In this study, the flow in 3D printed, patient-derived models was measured in vitro. Elastic modulus of materials were investigated to mimic the real brain arteries.

Hongwei Zhou¹, Derui Kong¹, and Tianjing Zhang^2
1The First Hospital of JiLin University, Changchun City,Jilin Province, China, ²Philips healthcare, Guangzhou City,Guangdong Province, China

The stability of intracranial of the middle cerebral artery(MCA) and basilar artery( BA) plaques related to the stroke events is a crucial issue. However, the discrimination of the plaque’s stability could be rather challenging. Compared with traditional imaging methods such as CTA, MRA or DSA, high-resolution vessel wall MR imaging(HR-VW-MRI) method could demonstrate the abnormality of the vessel wall .It could also potentially evaluate the stability of the intracranial artery. This study aims to compare HR-VW-MRI’s characteristic features of MCA plaque with BA plaque, and to figure out the relationship between plaques’ imaging features with the stroke events. 

Mingzhu Fu¹, Shuo Chen¹, Miaoqi Zhang¹, and Rui Li^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China

we studied the relationship between aneurysm wall enhancement and distribution of hemodynamic parameters including WSS and OSI on aneurysm wall from pixel-wise perspective based on the self-control of aneurysm. Statistics indicated that enhanced wall area of intracranial aneurysm had significant lower WSS and higher OSI.

Chunxue Wu¹, Mengqi Dong¹, Tao Hong², Hongqi Zhang¹, and Jie Lu^1
1Xuanwu Hospital Capital Medical University, Beijing, China, ²2030921@qq.com, Beijing, China

Digital subtraction angiography (DSA) is the golden standard of radiological technique for diagnosis and treatment evaluation of cerebral arteriovenous malformations (CAVMs). However, DSA is invasive and ionizing radiative. Silent MRA, which combines arterial spin labeling (ASL) and an ultrashort time echo (UTE), is used for CAVM structure visualization. The silent MRA is superior to TOF-MRA and enables the same Spetzler-Martin classification of cerebral AVM as that at DSA.

So Yeon Won¹, Jihoon Cha¹, Hyun Seok Choi¹, Young Dae Kim², Hyo Suk Nam², Ji Hoe Heo², and Seung-Koo Lee^1
1Radiology, Severance Hospital, Seoul, Korea, Republic of, ²Neurology, Severance Hospital, Seoul, Korea, Republic of

Our object is the evaluation of spatial relationship of MCA plaque and perforator in different types of MCA infarction using VW-MRI. We included 34 patients with acute MCA infarction and divided into 3 groups according to infarction pattern. We evaluated location relationship between perforators and plaques. Wall area, stenosis degree and plaque enhancement were calculated. There was difference in relationship between plaque and perforator, location and characteristics of plaque in different types of MCA infarction. In patients with BOD, the plaque margin was closer to perforator orifice with less stenosis and enhancement than patients with artery to artery embolism.

Hongwei Zhou¹, Derui Kong¹, and Tianjing Zhang^2
1The First Hospital of JiLin University, Changchun City,Jilin Province, China, ²Philips healthcare, Guangzhou City,Guangdong Province, China

Primary angiitis of the central nervous system(PACNS) is a kind of rare disease,but the clinical diagnosis is difficult. Recently,  high-resolution HR-3D-VW-MRI(3-dimensional vessel wall MR imaging) method has been used to evaluate cerebral vessels because it could directly show the vessel wall as well the lumen;thus it can assist in differentiating various types of vasculopathy. The purpose of our study was to summarize the typical imaging performance of PACNS and evaluate the value of 3D- VW-MRI sequence in demonstrating the detailed information in detection, diagnosis, evaluation, and follow-up for PACNS.

Mengjiao Wei¹, Yang Gao¹, Qiong Wu¹, Shaoyu Wang², and Huapeng Zhang^2
1Department of Radiology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China, ²MR Scientific Marketing, Siemens Healthineers, Shanghai, China

This study investigated the feasibility and accuracy of the maximum wall thickness(MWT), the lipid-rich necrotic core percentage(%LRNC) and the carotid atherosclerosis (CAS) score to predict stroke and diagnose vulnerable plaques. Our results showed that quantitative lipid-rich necrotic core can effectively diagnose vulnerable plaques and predict the risk of stroke, in addition, the CAS score can simply grade carotid artery plaques and provide a basis for clinical diagnosis and treatment.

Wei Qiu¹, Hanyu Wei¹, Shuo Chen¹, and Rui Li^1
1Center for Biomedical Image Research, Department of Medicine, Tsinghua University, Beijing, China

Image registration plays a prominent role in medical image processing pipeline¹. It’s of interest to assess pre-post variation for registered vessels on black blood MR images. In this research, Elastix tool was applied to register pre-contrast T1 and post-contrast T1 black blood images, use our own methods to actually and accurately evaluate the accuracy of the registration, and achieved promising quantitative results. The study suggests that Elastix performs good registration accuracy of the two images, and can be directly used for automatic image processing, so as to more conveniently serve clinical applications.

Haonan Zhang¹, Qingwei Song¹, Jiazheng Wang², Peng Sun², Renwang Wang¹, Nan Zhang¹, and Ailian Liu^1
1Department of Radiology, the First Affiliated Hospital of Dalian Medical University, Dalian, China, ²PHILIPS——Philips Healthcare, beijing, China

Traditional 3D-TOF Magnetic Resonance Angiography (MRA) in carotid imaging needs a relatively long scan time and is prone to be disturbed by motion artifacts such as vascular pulsation, respiratory movement, and some other physiological factors. A combination of compressed sensing (CS) can achieve high acceleration factors and thus lead to a significant reduction of scan time. Here, we investigated the impact of acceleration factors of compressed sensing on the image quality of 3D-TOF-MRA for cervical vessels. CS acceleration factor of 6 is recommended for clinical 3D-TOF carotid MRA to achieve an optimal balance between imaging time and image quality.

Samantha Cote¹, Reihaneh Forouhandehpour¹, Etienne Croteau¹, Diane Rottembourg², Jean-Francois Lepage², and Kevin Whittingstall^3
1Département de médecine nucléaire et radiobiologie, Université de Sherbrooke, Sherbrooke, QC, Canada, ²Département de pédiatrie, Université de Sherbrooke, Sherbrooke, QC, Canada, ³Département de radiologie diagnostique, Université de Sherbrooke, Sherbrooke, QC, Canada

We investigated if gender affirming hormonal therapy (GAHT) in young transgender men receiving testosterone (T) impacts cerebrovascular function and structure using pseudo-continuous arterial spin labelling (pCASL) and time of flight magnetic resonance angiography (TOF). We observed decreases in CBF and arterial vessel diameter. These results suggest an association between increased serum T and decreases in CBF which may be related to changes in cerebrovascular morphology.

Yuze Li¹, Chunmiao Chen², Yajie Wang¹, Jie Li², Xiaoli Sun², Shuiwei Xia², Lie Jin², Yani Ye², Jiansong Ji², and Huijun Chen^1
1Center for Biomedical Imaging Research, Medical School, Tsinghua University, Beijing, China, ²The Central Hospital of Zhejiang Lishui, Lishui, China

In this work, the vessel wall characteristics of carotid artery was measured on T1w, T2w and SNAP images in end-stage renal disease patients on dialysis. Totally, 94 patients were included. The time on dialysis was significantly and positively correlated with the mean wall area (p=0.012), normalized wall index (p=0.006), maximal wall thickness (p=0.005) and mean wall thickness (p=0.010). The presence of plaque was found to be significantly and independently associated with the dialysis type (p=0.047) and time on dialysis (p=0.032).