Fang Wu¹, Cong Han², Zhaoyang Fan³, and Qi Yang^4
1Radiology, Xuanwu hospital, Capital Medical University, Beijing, China, ²Department of Neurosurgery, 307 Hospital of Chinese People's Liberation Army, Beijing, China, ³Biomedical Imaging Research Institute, Cedars Sinai Medical Center, Los Angeles, CA, United States, ⁴Radiology, Xuanwu Hospital, Capital Medical University, Beijing, China

In this study, we used whole-brain vessel wall imaging (VWI) to characterize morphologies of middle cerebral artery (MCA) occlusion in patients with MMD, and explore their relationship to clinical findings. We found that plugged MCA was associated with ischemic stroke, however, vanishing MCA correlated with intraventricular hemorrhage. We also found that hemispheres with vanishing MCA manifested a higher degree of lenticulostriate artery (LSA) dilation and proliferation. The results suggest that there are two types of MCA occlusion in MMD, correlating with different stroke types and extent of perforator proliferation. Morphological analysis of occluded MCA using VWI may help understand the stroke mechanism of MMD.

Miaoqi Zhang¹, Shuo Han², Aaron Carass², Fei Peng³, Aihua Liu³, Jerry L. Prince², and Rui Li^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University, Beijing, China, ²The Johns Hopkins University, Baltimore, MD, United States, ³Department of Interventional Neuroradiology, Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, Beijing, China

In this work, we proposed an automatic segmentation algorithm of intracranial aneurysms from dual input 3D TOF-MRA and black-blood MRI (BB-MRI) using a deep convolutional neural network to study its clinical potential for assisting intracranial aneurysm detection. The positioning of an intracranial aneurysm can benefit from the TOF-MRA, and the BB-MRI image can be used to accurately trace its boundary and measure its size. The average Dice coefficients are 0.69 and 0.73 for the TOF-MRA and the BB-MRI images, respectively.

Shuai Yuan¹, Larry Davis¹, Petrice Cogswell², Spencer Waddle³, Lori Jordan¹, and Manus Donahue^4
1Vanderbilt University Medical Center, Nashville, TN, United States, ²Mayo clinic, Rochester, MN, United States, ³Vanderbilt University, Nashville, TN, United States, ⁴Vanderbilt University Medical Center Department of Radiology, Nashville, TN, United States

Sickle cell disease leads to increased risk of intracranial vasculopathy and stroke. Therefore, sensitive radiological indicators of cerebrovascular disease severity are needed to aid in treatment planning. 3T vessel wall imaging MRI studies demonstrated increased basilar artery wall thickness in sickle cell disease patients and inverse relationship between hematocrit and basilar wall thickness likely due to increased blood flow velocities and wall stress. Evaluation of internal carotid artery is difficult possibly due to variable CSF signal suppression in these regions.

Konstanze Viktoria Anna Valerie Guggenberger¹, Patrick Vogel¹, Nils Venhoff², Ute Ludwig³, Marc Schmalzing⁴, Esther Raithel⁵, Axel Joachim Krafft³, Thomas Ness⁶, Jost Hillenkamp⁷, Horst Urbach⁸, Stephan Meckel⁸, and Thorsten Bley^1
1Department of Diagnostic and Interventional Radiology, University Hospital Wuerzburg, Wuerzburg, Germany, ²Clinic for Rheumatology and Clinical Immunology, University Hospital Freiburg, Freiburg, Germany, ³Department of Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany, ⁴Rheumatology/Clinical Immunology Department, Internal Medicine II, University Hospital Wuerzburg, Wuerzburg, Germany, ⁵Siemens Healthcare, Erlangen, Germany, ⁶University Eye Center, University Hospital Freiburg, Freiburg, Germany, ⁷Department of Ophthalmology, University Hospital Wuerzburg, Wuerzburg, Germany, ⁸Department of Neuroradiology, University Hospital Freiburg, Freiburg, Germany

The extent of intracranial large artery involvement and its assessment is still part of on-going research. Our study group has developed a whole-brain T1-weighted dark blood CS-SPACE sequence suitable for intracranial vessel wall imaging in large-artery vasculitis combined with a dedicated post-processing tool. 53 patients were analyzed in a prospective blinded two university medical center trial. First clinical results demonstrate the technique`s suitability for clinical application. Mural thickening and contrast-enhancement as well as luminal changes are readily visible. However, certain confounders, especially atherosclerotic vessel wall lesions as well as vasa vasorum still propose major challenges for diagnosing intradural vasculitic affection.
 

Konstanze Viktoria Anna Valerie Guggenberger¹, Patrick Vogel¹, Nils Venhoff², Ute Ludwig³, Marc Schmalzing⁴, Esther Raithel⁵, Axel Joachim Krafft³, Thomas Ness⁶, Jost Hillenkamp⁷, Horst Urbach⁸, Stephan Meckel⁸, and Thorsten Bley^1
1Department of Diagnostic and Interventional Radiology, University Hospital Wuerzburg, Wuerzburg, Germany, ²Clinic for Rheumatology and Clinical Immunology, University Hospital Freiburg, Freiburg, Germany, ³Department of Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany, ⁴Rheumatology/Clinical Immunology Department, Internal Medicine II, University Hospital Wuerzburg, Wuerzburg, Germany, ⁵Siemens Healthcare, Erlangen, Germany, ⁶University Eye Center, University Hospital Freiburg, Freiburg, Germany, ⁷Department of Ophthalmology, University Hospital Wuerzburg, Wuerzburg, Germany, ⁸Department of Neuroradiology, University Hospital Freiburg, Freiburg, Germany

Superficial extracranial arteries are predilection sites for disease manifestation in large vessel vasculitides. We evaluated the suitability of a whole-brain T1-weighted dark blood CS-SPACE sequence, initially developed for intracranial vessel wall imaging, for visualization of vasculitic changes of superficial extracranial arteries. 53 patients were analyzed in a prospective blinded two university medical center trial. First clinical results demonstrate the technique`s applicability for clinical application. Mural thickening and contrast-enhancement of superficial extracranial arteries are clearly visible. The optimized VWI protocol offers potential for assessment of intra- and extracranial disease extent in case of suspected large vessel vasculitis in one single examination.

 

Shuai Han¹, Xinyi Wang², and Weiqiang Dou^3
1Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China, ²The First Affiliated Hospital of Shandong First Medical University, Jinan, China, ³GE Healthcare, MR Research, Beijing, China

The main goal of this study was to evaluate the treatment effect of primary angiitis of the central nervous system (PACNS) and secondary central nervous system vasculitis(CNSV) with high-resolution magnetic resonance vascular wall imaging. We measured 4 patients with PACNS and 10 patients with secondary CNSV using high resolution CUBE MRI. We found that high-resolution magnetic resonance vascular wall imaging can assess the treatment effect of PACNS and secondary CNSV. Therefore, CUBE MRI can be considered an effective tool in the evaluation of PACNS and secondary CNSV. 
 

Sheng Jiao¹, Juan Huang², Yan Song², Yuhui Chen³, Chengwen Liu⁴, Jinxia Zhu⁴, Jintao Zhang², and Min Chen^2
1Radiology, Beijing hospital, Beijing, China, ²Radiology, Beijing Hospital, Beijing, China, ³Neurology, Beijing Hospital, Beijing, China, ⁴MR Collaboration, Siemens Healthcare Ltd., Beijing, China

In this study we used high-resolution MRI to image intracranial atherosclerotic plaque more precisely, and then characteristics of plaque were obtained to compare with the blood glycemic (BG) level in Type 2 Diabetes mellitus (T2DM). Results demonstrated that patients with poor BG control had heavier intracranial plaque burden and more vulnerability than the patients without DM. While compared with non-DM, patients with good BG control showed no significant different in plaque burden. It suggested that BG level is an independent risk factor for the vulnerability of the intracranial atherosclerotic plaque.

Miran Han¹, Woo Sang Jung¹, and Jin Wook Choi^1
1Radiology, Ajou University Medical Center, Suwon, Republic of Korea

We evaluate the feasibility of HR-VWI for diagnosing PICA dissection. Our results demonstrated that HR-VWI could effectively diagnose arterial dissection even in PICA, small diameter vessel. The dissection flap with outer wall enlargement on T2W HR-VWI was most confident sign for diagnosing PICAD. Isolated PICAD is not a rare cause of ischemic stroke in posterior circulation. Therefore, in case of PICA territory infarction of uncertain origin, differentiating PICAD using HR-VWI is necessary for proper treatment of patients, and T2WI should be included in HR-VWI.

Qichang Fu¹, Yi Zhang¹, Sheng Guan², Chengcheng Zhu³, and Jingliang Cheng^1
1Department of Magnetic Resonance, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China, ²Department of Interventional Neuroradiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China, ³Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States

This study aimed to demonstrate the feasibility of aneurysmal wall enhancement (AWE) and wall enhancement index (WEI) in the identification of symptomatic and asymptomatic unruptured intracranial aneurysms by using vascular wall magnetic resonance imaging (VW-MRI) in a large cohort of Chinese patients with unruptured intracranial aneurysms (UIAs). VW-MRI were obtained at MAGNETOM Skyra/Verio/Prisma 3T MR scanner (Siemens Healthcare, Erlangen, Germany) in these patients. We found CAWE and WEI>0.91 were more frequently identified in symptomatic UIAs.

Song Liu¹, Ruowei Tang², Yu Luo³, Song Jin⁴, and Shuang Xia^5
1Radiology Department, Tianjin Huanhu Hospital, Tianjin, China, ²Radiology Department, Beijing Friendship Hospital, Capital Medical University, Beijing, China, ³Radiology Department, Shanghai Fourth People's Hospital, Shanghai, China, ⁴Tianjin Huanhu Hospital, Tianjin, China, ⁵Tianjin First Central Hospital, Tianjin, China

Ischemic stroke is the second frequent cause of death worldwide. Some patients have transient symptoms of neurological defect without parenchymal damage, irreversible cerebral tissue injury happens in someone else. How to discriminate TIA from acute stroke needs further study. This study uses muti-modal MRI scaning to investigate the difference of plaque characteristics in Middle Cerebral Artery (MCA) between patients with infarction and transient ischemic attack (TIA), and to explore the predictive model for infarction region and neurological impairment.

Bing Zhao¹, Jianshe Zhao¹, Weiqiang Dou², Chao Zhang³, Meijia Zhu³, and Xinyi Wang^3
1Department of Radiology, Qilu Children's Hospital of Shandong University, Jinan, China, ²GE Healthcare, MRI Research China, Beijing, China, ³Shandong Province Qianfoshan Hospital, Jinan, China

This study was aimed at investigating the clinical value of CUBE MRI for high resolution imaging and susceptibility weighted imaging (SWI) in the diagnosis of cerebral venous sinus thrombosis (CVST). The sensitivity, specificity, positive predictive value, and negative predictive value for 3D-CUBE T1 and SWI were calculated respectively. In this study, the diagnosis results of T1 weighted CUBE were better than that of SWI in comparison with the referential diagnosis in the detection of CVST. We therefore demonstrated that the T1 weighted CUBE MRI provided more effective usefulness than SWI in the diagnosis efficacy of the CVST.

Chae Jung Park¹, Jihoon Cha¹, Sung Soo Ahn¹, Hyun Seok Choi¹, and Seung-Koo Lee^1
1Department of Radiology, Severance hospital, Seoul, Republic of Korea

We investigated the clinical feasibility of compressed sensing (CS) in the intracranial vessel wall magnetic resonance imaging (VW-MRI) by applying CS to 3D post-contrast T1-weighted images (T1C). CS enabled larger scan coverage with nearly same scan time, while achieving comparable image quality, normal wall and lesion wall delineation. Furthermore, most T1C with CS provided acceptable quality with regard to overall image quality (84.7%), normal wall delineation (83.3%), and lesion wall delineation (97.8%), which was similar to T1C without CS. Therefore, CS is clinically feasible when applied to the post-contrast intracranial VW-MRI.

Chao Zhang¹, Xinyi Wang¹, Weiqiang Dou², and Bing Zhao^3
1The First Affiliated Hospital of Shandong First Medical University, Jinan, China, ²GE Healthcare, MR Research China, Beijing, China, ³Qilu Children's Hospital of Shandong University, Jinan, China

This study aimed to investigate the feasibility of CUBE MRI for high resolution imaging in the length measurement of intraluminal thrombi for acute stroke patients. The T1 weighted CUBE images displayed the segments proximal and distal to the thrombus with sufficient quality for clinical diagnosis, and showed the length of it as high signal or iso-signal filling in the lumen. As a result, about 88.9% of the thrombus lengths assessed by CUBE T1 were consistent with the reference DSA. We therefore, demonstrated that the T1 weighted CUBE MRI can effectively evaluate the length of intraluminal thrombi.

Xiudi Lu¹, Linglei Meng², Yongmin Zhou³, Shaoshi Wang², Miller Fawaz⁴, Meiyun Wang⁵, E. Mark Haacke⁴, Chao Chai⁶, Meizhu Zheng⁷, Jinxia Zhu⁸, Shuang Xia⁶, and Yu Luo^3
1The First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China, ²Shanghai Fourth People’s Hospital, Shanghai, China, ³Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People’s Hospital Affiliated to Tongji University School of Medicine, Shanghai, China, ⁴Wayne State University, Detroit, MI, United States, ⁵Zhengzhou University People’s Hospital, Zhengzhou, China, ⁶Tianjin First Central Hospital, Tianjin, China, ⁷Third Central Hospital of Tianjin, Tianjin, China, ⁸Siemens Healthcare Ltd, Beijing, China

This study aimed to measure ischemic penumbra volumes using susceptibility-weighted imaging and mapping (SWIM). We compared the diagnostic accuracy between SWIvolume-diffusion-weighted imaging (DWI) and SWIASPECTS-DWI mismatches and analyzed the relationships among the SWIvolume-DWI, SWIASPECTS-DWI, and PWI-DWI mismatches and the different parameters and NIHSS. We found that quantitative SWIvolume-DWI mismatch volumes were more accurate than those of the SWIASPECTS-DWI mismatch in being able to evaluate ischemic penumbra. The asymmetrical prominent cortical vein volumes using SWIM showed hypoperfused regions and Tmax >6s volumes, based on perfusion-weighted imaging (PWI). The quantitative SWIvolume-DWI mismatch was highly consistent with the PWI-DWI mismatch.

Audrey P Fan¹, David Y.T. Chen², David D. Shin³, Moss Y. Zhao¹, Mohammad M. Khalighi¹, Jun-Hyung Park¹, Bin Shen¹, Dawn Holley¹, Kim Halbert¹, Gary K. Steinberg⁴, and Greg Zaharchuk^1
1Radiology, Stanford University, Stanford, CA, United States, ²Radiology, Taipei Medical University, Taipei, Taiwan, ³GE Healthcare, Menlo Park, CA, United States, ⁴Neurosurgery, Stanford University, Stanford, CA, United States

In this [¹⁵O]-water PET/MRI study, we compared two non-invasive MRI techniques to measure brain oxygen extraction fraction (OEF) in 10 patients with Moyamoya disease, a steno-occlusive disease of arteries at the base of the brain. Relative OEF from magnetic susceptibility in veins and tissue R₂' inversely correlated with [¹⁵O]-water PET baseline cerebral blood flow and cerebrovascular reactivity (after vasodilation with acetazolamide). Susceptibility-based OEF in veins was abnormally elevated by 20.4% in regions with severe stenosis compared to healthy tissue. R₂' maps showed a smaller OEF elevation (9.6%) that may be confounded by other physiological changes (e.g. blood volume) in disease.

Maria Aristova¹, Kelly Jarvis¹, Michael Pan¹, Matthew Potts², Michael Hurley², Babak Jahromi², Ali Shaibani¹, Sameer Ansari¹, and Susanne Schnell^1
1Radiology, Northwestern University, Chicago, IL, United States, ²Neurosurgery, Northwestern University, Chicago, IL, United States

The Windkessel effect is hypothesized to be the mechanism of altered cerebral hemodynamics in intracranial aneurysms, via damping of pulsatile flow. 4D Flow MRI with specialized, network-based post-processing workflow provides damping factor (DF), by measuring pulsatility index (PI) ratio between proximal and distal vessels. PI values were higher in subjects with large aneurysms, even for contralateral vessels, suggesting patients with larger aneurysms may have other contributions to hemodynamics that also impact their vasculature outside the lesion. A multivariate linear correlation model shows that smaller aneurysms may have lower DF than contralateral, while larger aneurysms have higher DF ipsilateral than contralateral.

Xiao Cui¹, Xianshun Yuan¹, Hui Gu¹, Mo Wang², Yin Dong¹, Ximing Wang¹, and Xiang Feng^3
1Department of Radiology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China, ²Department of Vascular Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China, ³MR Scientific Marketing, Diagnosis Imaging, Siemens Healthcare Ltd, Beijing, China

This study aimed to compare the diagnostic values between HR-MRI and CTA in young adults with cervical artery dissections. Totally 42 patients with ischemic stroke were recruited, including 20 carotid artery dissections, 12 vertebral artery dissections and 10 non-dissected cervical arteries. Two radiologists separately analyzed all the images. According to the radiologists’ scores for the likelihood of the dissections, positive predictive value, negative predictive value, sensitivity and specificity for both modalities were calculated. We found the higher sensitivity and specificity of HR-MRI. This study supports the value of HR-MRI in non-invasive diagnosis of young adults due to cervical artery dissections.

Inpyeong Hwang¹, Chul-Ho Sohn¹, Won-Sang Cho², Jeong Eun Kim², Roh-Eul Yoo¹, Koung Mi Kang¹, Dong Hyun Yoo¹, Tae Jin Yun¹, Seung Hong Choi¹, and Ji-hoon Kim^1
1Department of Radiology, Seoul National University Hospital, Seoul, Korea, Republic of, ²Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea, Republic of

The purpose of this study was to evaluate whether super-selective ASL (SS-ASL) perfusion imaging could precisely visualize the revascularization area after bypass surgery in moyamoya disease, compared to digital subtracted angiography (DSA). Twenty-eight bypassed hemispheres of twenty-six patients in moyamoya disease underwent postoperative six months SS-ASL and DSA. Subjective image analysis of the revascularization area, as well as collateral grading, were performed. The agreement of the revascularization area was excellent (weighted kappa, 0.83), and agreement of collateral grading was good (weighted kappa, 0.722.) SS-ASL could evaluate revascularization territory precisely in the patient of moyamoya disease who underwent bypass surgery.

Nao Takano¹, Michimasa Suzuki¹, Yutaka Ikenouchi¹, Munetaka Yamamoto², Kohsuke Teranishi², Syo Murata¹, Nozomi Hamasaki¹, Haruyoshi Hoshito¹, Christina Andica¹, Toshiaki Akashi¹, Akihiko Wada¹, Hidenori Oishi³, and Shigeki Aoki^1
1Department of Radiology, Juntendo University Hospital, Tokyo, Japan, Tokyo, Japan, ²Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan, Tokyo, Japan, ³Department of Neuroendovascular Therapy, Juntendo University School of Medicine, Tokyo, Japan, Tokyo, Japan

We assessed the usefulness of ultrashort TE (UTE) 4D-MR angiography for giant aneurysms treated with flow-diverter stents. We evaluated the depiction of flow in the stents, and visualization of hemodynamic vascular flow in aneurysms. The newly developed UTE 4D-MRA could visualize flow in the stents at the acceptable quality for diagnosis, and hemodynamic vascular flow in aneurysms were comparable to X-ray DSA. Moreover, UTE 4D-MRA showed intraaneurysmal flow within the coil which was difficult to visualize even with X-ray DSA. Our study demonstrated that UTE 4D-MRA was adequate to visualize the hemodynamic vascular flow in aneurysms, and might be useful.  

Nao Takano¹, Michimasa Suzuki¹, Yutaka Ikenouchi¹, Munetaka Yamamoto², Kohsuke Teranishi², Syo Murata¹, Nozomi Hamasaki¹, Haruyoshi Hoshito¹, Christina Andica¹, Toshiaki Akashi¹, Akihiko Wada¹, Hidenori Oishi³, and Shigeki Aoki^1
1Department of Radiology, Juntendo University Hospital, Tokyo, Japan, Tokyo, Japan, ²Department of Neurosurgery, Juntendo University School of Medicine, Tokyo, Japan, Tokyo, Japan, ³Department of Neuroendovascular Therapy, Juntendo University School of Medicine, Tokyo, Japan, Tokyo, Japan

We evaluated the usefulness of non-contrast enhanced ultrashort TE MRA (Silent MRA) for intracranial aneurysms treated with flow-diverter (FD) stents and coils. FD stent has a higher metal coverage, thus it is difficult to visualize in-stent flow using TOF-MRA, due to the magnetic susceptibility. In contrast, silent MRA uses ultrashort TE, therefore may visualize in-stent flow. In silent MRA, in-stent flow score was superior to that of TOF-MRA (p<0.05). Moreover, aneurysm occlusion status was in good agreement with X-ray DSA (κ = 0.84). Therefore, silent MRA is useful for the evaluation of intracranial aneurysms treated with FD stents and coils.

Bing-Fong Lin¹, Po-Yi Tsai², and Chia-Feng Lu^1
1Biomedical imaging and radiological sciences, National Yang-Ming University, Taipei, Taiwan, ²Taipei Veterans General Hospital, Taipei, Taiwan

Low-frequency repetitive transcranial magnetic stimulation (rTMS) provided promising results to facilitate the language recovery in stroke patients with non-fluent aphasia. This study demonstrated a contralesional inhibitory rTMS treatment can modulate the brain functional networks compare to the conventional therapy. The modulated functional networks were further correlated with the improvement of language performance after the rTMS treatment.

Yu Guo^1,2, Jiayu Xiao², Zhongying Gong³, Wen Shen¹, Shuang Xia¹, and Zhaoyang Fan^2
1Radiology, Tianjin First Central Hospital, tianjin, China, ²BIRI, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ³Neurology, Tianjin First Central Hospital, tianjin, China

This study aimed to investigate atherosclerotic plaque characteristics in middle cerebral artery (MCA) atherosclerotic patients with border-zone (BZ) infarction using magnetic resonance vessel wall imaging (MR-VWI). In 84 retrospectively enrolled ischemic stroke patients caused by MCA atherosclerosis, the characteristics of culprit plaques were quantitatively compared between BZ only infarction and combined border-zone and pial (BZ+PI) infarction groups. BZ+PI infarction was associated with a higher degree of stenosis and higher plaque-wall contrast ratio and enhancement ratio, compared with BZ only infarction, suggesting that embolic pathogenesis may also account for BZ+PI infarction in addition to hemodynamic compromise.

Junghyeob Kim¹, Yejin Jo², Jae Eun Song¹, Hyunjung Kim², Deogyoung Kim², and Dong-Hyun Kim^1
1Electrical & Electronic Engineering, Yonsei University, Seoul, Republic of Korea, ²Department and Research Institute of Rehabilitation Medicin, Yonsei University College of Medicine, Seoul, Republic of Korea

Stroke is a worldwide disease and requires quantitative evaluation for better patient management. In evaluating rehabilitation of stroke patients, quantitative analysis was performed using the conventional DTI-FA and multi echo GRE Myelin Water Fraction mapping technique

Bing Tian¹, Zhang Shi², Xia Tian², Qi Liu², and Jianping Lu^2
1Radiology, Changhai hospital of Shanghai, Shanghai, China, ²Changhai hospital of Shanghai, Shanghai, China

HR-MRI is helpful for the classification of IAD, could be used to identify the culprit IAD from non-culprit ones.

Guiling Zhang¹, Zhenxiong Wang¹, Weiyin Vivian Liu², and Wenzhen Zhu^1
1Tongji hospital, Wuhan, China, ²MR Research, GE Healthcare, Beijing, China

High risk plaque is the is the predominant risk factor of stroke. Accurate diagnosis and intervention could prevent patients from cerebrovascular events. Axial, circumferential and 3D wall shear stress calculated by 4D flow MRI were utilized to explore the difference between high risk plaque patients and low risk plaque patients. The results demonstrated the WSS were all significant higher in high risk plaque group. Our results may provide crucial clues to therapeutic interventions.

Chao-Chun Lin¹, Wen-Chau Wu², Woei-Cherng Shyu³, Yi-Jui Liu⁴, Hing-Chiu Chang⁵, Yu-Chien Luo³, Der-Cherng Chen³, Chia-Wei Lin³, Hsiao-Wen Chung⁶, and Shinn-Zong Lin^7
1Department of Radiology, China Medical University Hospital, Taichung, Taiwan, ²Institute of Medical Device and Imaging, National Taiwan University, Taipei, Taiwan, ³China Medical University Hospital, Taichung, Taiwan, ⁴Department of Automatic Control Engineering, Feng-Chia University, Taichung, Taiwan, ⁵Department of Diagnostic Radiology, University of Hong Kong, Hong Kong, Hong Kong, ⁶Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, ⁷Buddhist Tzu Chi General Hospital, Hualien, Taiwan

Dynamic susceptibility-contrast perfusion-weighted MRI was performed on 15 chronic stroke patients receiving intracerebral implantation of peripheral blood stem cells (PBSC) at baseline and 6 longitudinal stages after therapy to derive relative cerebral blood volume around the implanted graft relative to contralateral white matter (rCBV ratio), with 15 control patients receiving baseline MRI plus two follow-ups. Nine of the 15 patients (60%) in the PBSC group showed significantly increased rCBV ratio than the baselines (1.39±0.60 versus 1.07±0.44; p < 0.01) at one week after implantation only, preceding functional improvements starting at one month as assessed by NIH stroke scale.

Yuhan Jiang¹, Yanwei Miao¹, Liangjie Lin², Zhiwei Shen², Peipei Chang¹, Yiwei Che¹, Ailian Liu¹, Qingwei Song¹, and Jiazheng Wang^2
1the First Affiliated Hospital of Dalian Medical University, Dalian, China, Dalian, China, ²Philips Healthcare, Beijing, China, Beijing, China

The presence, dynamic evolution, and outcome of the ischemic penumbra (IP) are important for the choice of treatment options and prognosis. At present, there is currently no study to combine the APTw MRI with the blood flow measurements for IP analyses. Purpose of this study was to analyze the association between APT metabolic changes and blood flow status in the IP of patients with subacute infarction in the unilateral middle cerebral artery by APT and ASL techniques. Significant correlations of APTw values to CBF values of PLD1.5.

Sophie Schauman¹, Joseph G. Woods^1,2, Mark Chiew¹, and Thomas W. Okell^1
1Wellcome Centre for Integrative Neuroimaging, NDCN, University of Oxford, Oxford, United Kingdom, ²Department of Radiology, University of California San Diego, La Jolla, CA, United States

Time-encoded (TEnc) dynamic ASL angiography is a method that provides high SNR, dynamic information about the blood supply to the brain. However, as is commonly the case with all ASL-based methods, multiple repeat encodings are required to fully sample the information required to decode the dynamic angiographic data. Here we apply spatial sparsity and temporal smoothness constraints to reconstruct highly under-sampled TEnc data, and demonstrate that high fidelity, high resolution ASL angiography can be performed in a fraction of the time it takes using conventional methods.

Kosuke Morita¹, Masami Yoneyama², and Takeshi Nakaura^3
1Kumamoto University Hospital, Kumamoto, Japan, ²Philips Japan, Tokyo, Japan, ³Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan

Multi-slice single-shot 2D echo-planar imaging (EPI) readout can be used effectively for pseudo-continuous arterial spin labeling (pCASL) perfusion imaging. In this study we tried to utilize the Compressed SENSE reconstruction for pCASL-EPI without further optimization of EPI sampling scheme. pCASL-EPICS clearly reduces noise-like artifacts and significantly improves the robustness of perfusion images in a short scan time less than 3 minutes compared with conventional pCASL SENSE, without any penalty for scan parameters. This technique may be helpful to further assess the many brain diseases.

Eva Elisabeth van Grinsven¹, Allen A. Champagne², Marielle Philippens³, and Alex Bhogal^4
1Department of Neurology & Neurosurgery, University Medical Center Utrecht Brain Center, Utrecht, Netherlands, ²Center for Neuroscience studies, School of medicine, Queen’s University, Kingston, ON, Canada, ³Department of Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands, ⁴Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands

This study compared multiple BOLD cerebrovascular reactivity (CVR)-metrics during breath holding (BH) versus a targeted CO₂ challenge to determine the degree of similarity in extracting dynamic information about hemodynamic reserves. The preliminary data confirm previous research; CVR-maps were spatially comparable and correlated well between the two stimuli. That said, the data suggests reliable information regarding the flow dynamics is best provided by a controlled CO₂ stimulus. Thus, even though BH may be easier to implement, it may also be limited in its ability to provide additional information regarding cerebrovascular health (beyond CVR), which could be of value when investigating patients. 

Vincent Jerome Schmithorst¹, Cecilia Lo², Philip Adams², and Ashok Panigrahy^1
1Radiology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States, ²University of Pittsburgh, Pittsburgh, PA, United States

Estimation of cerebrovascular reserve/reactivity (CVR) typically necessitates an invasive vasoactive stimulus.  We here propose a metric to non-invasively estimate “resting-state” CVR (rCVR), the capacity of the vasculature to respond to resting-state metabolic demand, as the negative ratio of functional connectivity strength (FCS) to regional cerebral blood flow (CBF).  Construct validity was demonstrated via prediction of end-tidal CO2 levels (PETCO2).  rCVR was lower in older children with congenital heart disease (CHD) in default mode network (DMN), salience network (SN), and central executive network (CEN), and was positively associated with neurocognitive outcome (NIH Toolbox) and nasal nitric oxide (nNO) levels.

Abraham Noorbakhsh¹ and Divya Bolar^1
1Department of Radiology, University of California, San Diego, San Diego, CA, United States

A retrospective review was performed of 50 patients undergoing MRI with pseudo-continuous arterial spin labeling (pCASL) perfusion imaging and confirmed unilateral fetal PCA. The aim is to determine the frequency of visually-apparent unilateral PCA territory hypoperfusion in patients with a contralateral fetal PCA, but without underlying clinical or imaging pathology to suggest true hypoperfusion. Eight of the fifty cases (16%) had visually-apparent hypoperfusion in the PCA territory contralateral to the fetal PCA. Given these findings, we advise caution when interpreting ASL in patients with a fetal PCA/variant circle of Willis anatomy or suggest using longer post-labeling delay times.

Tine Arts¹, Laurien Onkenhout², Doeschka Ferro², Eline Oudeman², Jaap Kappelle², Thijs van Osch³, Jaco Zwanenburg¹, Jeroen Hendrikse¹, and Geert Jan Biessels^2
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, ²Neurology, University Medical Center Utrecht, Utrecht, Netherlands, ³Radiology, Leiden University Medical Center, Leiden, Netherlands

Recently, flow velocity and pulsatility can be measured in cerebral perforating arteries. However, whether this perforator function is independent of upstream large vessel function is unknown. This study therefore investigates cerebral perforator velocity and pulsatility in the centrum semi-ovale (CSO) and basal ganglia (BG) using 7 Tesla MRI in patients with carotid occlusive disease and controls, and in patients inter-hemispherical. Cerebral perforator function was found to be similar in patients and controls, and also similar between hemispheres of patients with unilateral COD. These results show that cerebral arterial perforator function is independent of upstream large vessel disease.

Minoru Morikawa¹, Hideki Ishimaru¹, Yohei Ikebe¹, Masataka Uetani¹, Reiko Ideguchi², Hiroshi Imai³, and Naoharu Kobayashi^4
1Department of Radiology, Nagasaki University Hospital, Nagasaki, Japan, ²Department of Radioisotope Medicine, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan, ³Siemens Healthcare K.K., Tokyo, Japan, ⁴Department of Radiology, University of Minnesota Medical School, Minneapolis, MN, United States

Gradient modulated pointwise encoding time reduction with radial acquisition sequence (GM-PETRA) is a new sequence, which can minimize metallic artifact caused by surgical clips. The GM-PETRA samples k-space more quickly by increasing the gradient amplitude after excitation while keeping a relatively low excitation bandwidth. GM-PETRA provides decrease the susceptibility artifact caused by a metallic implant such as surgical clip and can demonstrate the patency of parent artery adjacent to the surgical clip more clearly than conventional PETRA and TOF MRA.

Boyu Zhang¹, Bei Wang¹, Chengyan Wang², Ying-Hua Chu³, and He Wang^1,2
1Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China, ²Human Phenome Institute, Fudan University, Shanghai, China, ³MR Collaboration, Siemens Healthcare Ltd., Shanghai, China

Cerebral vascular alterations are leading risk of several brain diseases. To detect the structural alterations, we proposed the novel framework to automatically generate the cerebrovascular probability atlas and corresponding radius and tortuosity atlas using multistage segmentation and concatenated registration method. 198 hypertension patients and 149 health participants scanned with TOF MRA and T1 sequences were included in our study. The tortuosity in middle cerebral artery and posterior cerebral artery are obviously higher in hypertension group, which may reveal the intrinsic mechanism of cerebrovascular structural changes in hypertension.

Maarten J. Versluis¹, Yi Wang², Karthik Gopalakrishnan³, Burkhard Maedler⁴, Charles Truwit⁵, Velmurugan Gnanaprakasam¹, Johan van den Brink¹, and Liesbeth Geerts^1
1BIU MR, Philips Healthcare, Best, Netherlands, ²Clinical Science, Philips Healthcare, Seattle, WA, United States, ³BIU MR, Philips Healthcare, Bangalore, India, ⁴Clinical Science, Philips Healthcare, Hamburg, Germany, ⁵Diagnostic Imaging, Philips Healthcare, Cambridge, MA, United States

In this study we compared the image quality of CE-MRA scans using Compressed SENSE and SENSE reconstruction in three subjects. A visual comparison between the number of intracranial vessels showed no differences for both reconstruction techniques. Structural Similarity Index (SSIM) and Mean squared error (MSE) metrics were used to compare retrospectively undersampled CS-SENSE and SENSE acquisitions at a number of reduction factors with the fully sampled dataset. It was found that CS-SENSE reconstructed scans show a higher similarity to the fully sampled acquisitions than using conventional SENSE parallel imaging allowing a 50% increase in acceleration compared to SENSE.

Zhangli Xing¹, Yunjing Xue¹, Bin Sun¹, and Pu-Yeh Wu^2
1Fujian Medical University Union Hospital, Fuzhou, China, ²GE Healthcare, MR Research China, Beijing, China

We used 3D-TOF-MRA and territorial-ASL (t-ASL) maps to investigate the relationship between anatomical morphology of circle of Willis (CoW) and the primary collateral blood flow in physiological conditions. We found that the primary collateral blood flow had a direct relationship with anatomical structure of CoW. A1 segment has a role in controlling the blood flow in anterior circulation, while in posterior circulation, P1 segment and PcomA cooperate to dominate the blood flow.

Lijuan Wang¹, Songan Shang¹, Weiqiang Dou², Jianxun Qu², Jing Ye¹, and Jingtao Wu^1
1Northern Jiangsu People’s Hospital, Yangzhou, China, ²GE Healthcare, Beijing, China

In this study, we aimed to investigate the feasibility of a hybrid arterial spin labeling (hASL) zero-echo-time (zTE) magnetic resonance angiography (MRA) for intracranial arteries. Comparing with the conventional zTE MRA (continuous ASL, cASL), the hASL-zTE-MRA showed higher signal homogeneity in the proximal intracranial arteries. Additionally, hASL-zTE-MRA provided more robust performance in depicting cerebrovascular diseases, such as stenosis and arteriovenous malformation (AVM). We therefore demonstrated that the utilization of hASL strategy could potentially improve the image quality of zTE-MRA, and further be applied routinely in the clinic for patients with cerebrovascular diseases.

Mingzhen Wu¹, Weiqiang Dou², Chengbing He¹, Xiaoqian Huang¹, Jixin Luan¹, Chuanying Shi¹, and Chuanchen Zhang^1
1Liaocheng People's Hospital, Liaocheng, China, ²GE Healthcare, MR Research China, Beijing, China

This study aimed to investigate if zero-echo-time arterial-spin-labeling (ZTE ASL) MRA is feasible in the diagnosis of intracranial artery stenosis(ICAD). 25 patients with confirmed clinically stroke or transient ischemic attacks were recruited. For these patients, the correspondingly acquired ZTE-MRA images were compared with those using TOF-MRA technique. DSA imaging was also applied for and considered as a reference standard. For large-medium-sized intracranial arterial segments, ZTE-MRA showed better performance in the image quality and diseased artery detection than TOF-MRA. Therefore, ZTE-MRA can be considered as a promising technique to be further applied in the clinic routinely for patients with ICAD.

Xuan Zhang¹, Yue zhou Cao², Yi Sun³, Michaela Schmidt⁴, Christoph Forman⁴, Peter Speier⁴, and Shanshan Lu^1
1Radiology department, The first affiliated hospital of nanjing medical university, Nanjing, China, ²Interventional Radiology department, The first affiliated hospital of nanjing medical university, Nanjing, China, ³MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China, ⁴Siemens Healthcare GmbH, Erlangen, Germany

As a widely used technique for cerebrovascular disease, the anatomical coverage of TOF-MRA is often limited in order to achieve a compromise between high spatial resolution and acceptable scan time. Compressed sensing (CS) is an effective technique for accelerating 3D acquisitions. In this study, we report the preliminary results of CS TOF-MRA for diagnosing head and neck arterial steno-occlusive disease by taking DSA as the reference standard. CS TOF-MRA provides a relatively large coverage, high resolution, good image quality and comparable diagnostic accuracy to DSA in the assessment of head and neck arterial stenoses within a reasonable acquisition time.

Jinhao Lyu¹, Xiangbing Bian¹, Liuxian Wang¹, Yina Lan¹, Xin Zhou², Lin Ma¹, and Xin Lou^1
1Department of Radiology, Chinese PLA General Hospital, Beijing, China, ²State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences‐Wuhan National Laboratory for Optoelectronics, Wuhan, China

Bright vessel appearance on arterial spin labeling (ASL) had been reported to be a useful marker for localizing arterial occlusion in acute ischemic stroke. But ischemia due to cerebral arterial occlusion did not always show bright vessel appearance on ASL. In the present study, we found that the presence of bright vessel appearance may associate with thrombus age and be able to specifically identify acute cerebral arterial occlusion. The findings may help to optimize current stroke protocols and facilitate the diagnosis of fresh thrombus, thus to support the treatment decision making in stroke patients with large vessel occlusion.

Yuzhu Yan¹, Dan Tong¹, Xiaochao Liu², Xiaolei Wang¹, Zhuo Wang¹, Fan Yang¹, and Lizhi Xie^3
1radiology, The first hospital of Jilin University, Changchun, China, ²The third people's hospital of Datong, Datong, China, ³GE Healthcare, MR Research China,Beijing, Beijing, China

The Willis ring plays an important role in the collateral circulation especially in patients with internal carotid artery (ICA) stenosis. However conventional time of flight (TOF) MR angiography may only offer limited knowledge of the compensatory blood flow attributed to collateral circulation for patients with stenosis. Vessel selective arterial spin labeling allows the assessment of blood flow of a specific vessel. The purpose of this study was to quantify the influence of various anatomical types on the compensatory capacity of the Willis ring for patients with severe stenosis or occlusion using combined TOF MRA and vessel selective ASL method.

Meher Juttukonda^1,2, Spencer Waddle³, Larry Davis³, Chelsea Lee⁴, Niral Patel⁴, Sumit Pruthi³, Adetola Kassim⁵, Manus Donahue³, and Lori Jordan^4
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, ²Radiology, Harvard Medical School, Boston, MA, United States, ³Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, United States, ⁴Pediatrics-Division of Pediatric Neurology, Vanderbilt University Medical Center, Nashville, TN, United States, ⁵Medicine-Division of Hematology/Oncology, Vanderbilt University Medical Center, Nashville, TN, United States

Venous hyperintense signal in arterial spin labeling (ASL) MRI has been associated with abnormal tissue-capillary water exchange in adults with sickle cell anemia (SCA). We tested the hypothesis that such hyperintense signal is associated with reduced oxygen extraction fraction (OEF) in adults with SCA. Higher categorical scores of shunting were associated with lower OEF in SCA participants with silent infarcts and/or white matter lesions but not in participants without lesions. These findings indicate that venous hyperintense signal in ASL images may reflect impaired abilities of blood to subserve oxygen and may contribute to lesion development in SCA patients.

Hanne A Stotesbury¹, Mboka Jacob², Jamie M. Kawadler¹, Dawn E. Saunders^1,3, Chris A. Clark¹, and Fenella J. Kirkham^1
1Imaging and Biophysics, Developmental Nerosciences, UCL Great Ormond St Institute of Child Health, London, United Kingdom, ²Department of Radiology & Imaging, Muhimbili University of Health and Allied Sciences, Dar Es Salaam, Tanzania, ³Department of Radiology, Great Ormond Street Hospital, London, United Kingdom

Reductions in white matter integrity are associated with neurocognitive dysfunction in sickle cell anemia (SCA) patients, but the aetiology is poorly understood. Aiming to explore whether anemia severity, silent cerebral infarction (SCI), and vascular abnormalities may all play a role, we conducted tract-based-spatial statistics in 62 Tanzanian children with SCA. We found anemia severity to be independently associated with increased mean and axial diffusivity, SCI with increased radial diffusivity, and turbulence or vasculopathy with reduced fractional anisotropy. Our findings are consistent with a model of neurological complications in which these pathologies may all contribute to functionally-significant reductions in tissue integrity.

Hanne A Stotesbury¹, Russell Murdoch², Patrick Hales¹, Jamie M. Kawadler¹, Melanie Kölbel ¹, David Carmichael³, Chris A. Clark¹, Fenella Kirkham¹, and Karin Shmueli^2
1Imaging and Biophysics, Developmental Nerosciences, UCL Great Ormond St Institute of Child Health, London, United Kingdom, ²Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom, ³Biomedical Engineering & Imaging Sciences, Kings College London, London, United Kingdom

In 15 homozygous sickle-cell disease patients (SCD; hemoglobin-SS) and 12 healthy controls (HC; 10 Hb-AA, 2 Hb-AS), we compared a quantitative susceptibility mapping (QSM)-based estimate of venous oxygen saturation (Yv) with T2-relaxation-under-spin-tagging (TRUST)-based estimates using bovine-hemoglobin (TRUST-HbBV), hemoglobin-S (TRUST-HbS), or hemoglobin-A (TRUST-HbA) calibrations. Agreement between methods varied, with QSM-Yv estimates in HC and SCD respectively on average 5-6% higher versus TRUST-HbBV, 5% higher and 9% lower versus TRUST-HbS, and 9% higher and 2% lower versus TRUST-HbA. Across all comparisons, the limits of agreement were wide (18-26%) underscoring the need for further studies comparing non-invasive methods with gold-standard jugular vein catheterization.

Tianhao Su¹, Philippe Reymond², Olivier Brina², Long Jin¹, Karl-Olof Lovblad², and Maria Isabel Vargas^2
1Interventional radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China, ²Neuroradiology and Neuro-interventional radiology, University Hospitals of Geneva, Geneva, Switzerland

Flow diverter (FD) has recently been introduced for cerebral aneurysms, especially for the uncoilable sidewall type in the tortuous internal carotid artery (ICA). However, some of treated aneurysms remain patent in clinical practices, probably because of hemodynamic reason. Four-dimensional phase contrast sequences (4D flow MRI) targeting the aneurysm bulge were prospectively performed. The results showed that intense hemodynamic effect at the aneurysmal neck and large ostium might need a longer time for FD induced occlusion. 4D flow MRI before FD procedures has the potential to depict and quantify ostium hemodynamics that could bring new insights in characterizing their treatment responses.

Danhui Fu¹, Guanqiao Jin¹, Wenjuan Deng¹, Weiyin Vivian Liu², Long Qian², and Danke Su^1
1GuangXi Medical University Cancer Hospital, Nanning, China, ²MR Research, GE Healthcare, Beijin, China

A bulk of research shows reduced cerebral blood flow is linked to thinning of the cortex and cognitive impairment in dementias and vascular disease while negative relations between functional connectivity and cognition in health are positive in HIV. Our findings of significantly increased CBF in the bilateral middle occipital gyri (MCG) while only left MCG negatively correlated with time for Stroop Color in HIV⁺ group might underpin that the transition from normal cognition to cognitive impairment in compensation for the abnormal structural and functional alterations. CBF values might reflect hemodynamic differences in HIV⁺ patients without signs of HIV-associated neurocognitive disorder.

Spencer L. Waddle¹, Ifeanyi Ikwuanusi¹, Lori C. Jordan^1,2,3, Chelsea A. Lee^1,2, Niral J. Patel^1,2, Sumit Pruthi¹, L. Taylor Davis¹, Allison Griffin¹, Michael R. Debaun^4,5, Adetola A. Kassim⁵, and Manus J. Donahue^1,3,6
1Department of Radiology, Vanderbilt University Medical Center, Nashville, TN, United States, ²Department of Pediatrics, Division of Pediatric Neurology, Vanderbilt University Medical Center, Nashville, TN, United States, ³Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, United States, ⁴Department of Pediatrics, Vanderbilt-Meharry Center for Excellence in Sickle Cell Disease, Vanderbilt University Medical Center, Nashville, TN, United States, ⁵Department of Internal Medicine, Division of Hematology/Oncology, Vanderbilt University Medical Center, Nashville, TN, United States, ⁶Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN, United States

Sickle cell disease (SCD) comprises multiple sickle phenotypes, yet it is assumed that most phenotypes have similar cerebral hemo-metabolic impact, despite differing hematological characteristics. Here, patients (n=120) with the two most common phenotypes, hemoglobin (Hb)-SS and HbSβ⁰-thalassemia, were evaluated using anatomical, cerebral blood flow (CBF)-weighted, and oxygen extraction fraction (OEF)-weighted 3T MRI. Results suggest that while CBF depends closely on hematocrit, SCD phenotype does not discriminate either CBF or OEF and anatomical findings of prior infarct and vasculopathy were not significantly different between groups. These findings are consistent with HbSβ⁰ and HbSS phenotypes having similar impact on cerebral hemo-metabolic dysfunction.

Soyoung Choi^1,2, Chau Vu³, Richard M Leahy⁴, and John Wood^5
1Neuroscience Graduate Program, University of Southern California, LOS ANGELES, CA, United States, ²Children's Hospital Los Angeles, LOS ANGELES, CA, United States, ³Biomedical Engineering, University of Southern California, LOS ANGELES, CA, United States, ⁴Signal and Image Processing Institute, University of Southern California, Los Angeles, CA, United States, ⁵Division of Hematology, Children's Hospital Los Angeles, Los Angeles, CA, United States

Patients with chronic anemia has been shown to be susceptible to structural, functional and cognitive impairments. This study explores differences in white matter microstructure (measured by ADC) and cerebrovascular perfusion patterns (measured by MTT) and their relationship to hemoglobin in patients with sickle cell anemia, non-sickle anemia and controls. Larger ADC values and faster MTT is found along the anterior circulation of the brain in sickle-cell anemic patients. Relationships were found between hemoglobin, ADC and MTT in controls that were not observed in sickle-cell patients possibly indicating microvascular dysregulation. Our observations indicate possible microvascular dysregulation in sickle cell anemic patients.

Rong Wang¹, Yuxin Li¹, Jie Lin¹, Chong Sun¹, Daoying Geng¹, and Liqin Yang^1
1Huashan Hospital, Shanghai, China

This is the first study that used resting-state fMRI (rs-fMRI) to assess the alterations of spontaneous neuronal activity in patients with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) at attack and remission stages, which may provide a new insight into the mechanisms of cerebral cortex damage in MELAS.

Shengyuan Ma¹, Linjie Wang², Mo Zhu², Yanle Hu³, Yiping Du¹, Joel R. Garbow⁴, Curtis Johnson⁵, Chun-hong Hu², and Yuan Feng^1
1Shanghai Jiao Tong University, Shanghai, China, ²Department of Radiology, The first affiliated hospital of Soochow University, Suzhou, China, ³Mayo Clinic, Phoenix, AZ, United States, ⁴Washington University in St. Louis, St. Louis, MO, United States, ⁵University of Delaware, Newark, DE, United States

Measurements of the biomechanical properties of the cerebral vessels could help diagnosis and prognosis of diseases such as lacunar infarction. In this study, shear moduli of the cerebral vessels were measured using both magnetic resonance elastography (MRE) and MR Angiography (MRA). The magnitude images from MRE were registered to MRA images to obtain the shear moduli of the cerebral vessels. Results showed significant correlations between age and gender in terms of the storage modulus. Significant differences between lacunar infarction and healthy control group were also observed in terms of the absolution shear modulus.

Chuanying Shi¹, Weidong Liu², Chuanchen Zhang¹, Jiheng Hao², Weiqiang Dou³, Jipeng Wang¹, and Jixin Luan^1
1Radiology, Liaocheng people's hospital, Liaocheng, China, ²Neurosurgery department, Liaocheng people's hospital, Liaocheng, China, ³MR Research China, GE Healthcare, Beijing, China

In patients with Moyamoya disease, posterior collateral circulation plays an important role in defending ischemic syndrome and good revascularization outcome. The association between bypassing perfusion and posterior collateral circulation remains unknown. This study thus used territory arterial spin labeling to evaluate the territory changes of these vessels. Our results showed that good bypassing perfusion is along with the improvement of posterior collateral perfusion territory. This indicates that good operation outcome was not only associated with poor collateral perfusion, but also related with good collateral vessels functioning as blood channels.

Rama Jayasundar¹, Dushyant Kumar¹, Rajesh Mishra¹, Govind Maurya¹, Priyanka Bhagat², Surbhi Kaura², Senthil Kumaran¹, and Padma Srivastava^2
1Department of NMR, All India Institute of Medical Sciences, New Delhi, India, ²Department of Neurology, All India Institute of Medical Sciences, New Delhi, India

This MRI based study has evaluated for the first time, the cortical structural changes effected by physiotherapy in post-stroke (ischemic) recovery. Patients (n=7) with deficits did physiotherapy for one hour daily for six months under bi-weekly supervision of certified physiotherapists. Pre- and post-physiotherapy intervention assessment involved NIHSS and mRS scores and MRI at 3T. The latter included 3D-T1, 3D-FLAIR and fMRI (motor task). Preliminary findings showed individual patients’ positive response to physiotherapy reflected in the significantly reduced NIHSS and increased mRS scores, the recovery of fMRI activation and increase in cortical gray matter volume in specific anatomical locations in brain. 

Liu-Xian Wang¹, Hui Wang², Jin-Hao Lyu¹, Fang-Bin Hao², Lian Duan², and Xin Lou^1
1The First Medical Center of Chinese PLA General Hospital, Beijing, China, ²The Fifth Medical Center of Chinese PLA General Hospital, Beijing, China

Previous study has reported superiority of contrast-enhanced T1-weighted MR (CEMR) imaging compared with FLAIR for depicting ivy sign in Moyamoya disease (MMD), but no quantitative comparison of both scoring modalities was performed. In this study, we found better consistency between CEMR and DSA, higher ability of CEMR to differentiate severity of MCA stenosis, as well as higher specificity of CEMR compared with FLAIR. Our study proposed that for chronic cerebrovascular disease like MMD, CEMR might be more appropriate in assessing leptomeningeal collaterals.

Yannan Yu¹, Yuan Xie¹, Thoralf Thamm¹, Enhao Gong¹, Jiahong Ouyang¹, Soren Christensen¹, Michael P Marks¹, Maarten G Lansberg¹, Gregory W Albers¹, and Greg Zaharchuk^1
1Stanford University, Stanford, CA, United States

Ischemic core of acute ischemic stroke is commonly defined by diffusion-weighted imaging (DWI). CT perfusion, although widely used for acute stroke triaging, is challenging to identify the ischemic core as precise as DWI. In this study, we predicted the DWI lesion from MR perfusion-weighted imaging using U-Net. We found U-net model can predict the ischemic core from perfusion imaging with a better performance compared to clinically-used relative cerebral blood flow map thresholding. In the future study, we will apply the model to patients underwent CT perfusion using transfer learning.

Yiwei Che¹, Yanwei Miao¹, Yuhan Jiang¹, Peipei Chang¹, and Lizhi Xie ^2
1Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China, ²Department of Radiology, GE healthcare, Beijing, China

Systemic lupus erythematosus (SLE) is a diffuse connective tissue disease, which can involve the nervous system, and cerebrovascular damage is the most common. Yet, the relationship between SLE and Cerebral small vessel disease (CSVD) are still not clear. The following study evaluated the MRI findings of enlarged perivascular space (EPVS), white matter hyperintense (WMH) and lacunes of CSVD in patients with SLE. The results showed that CVSD in SLE group was more serious than healthy normal control group, and complement C3 and disease duration were the influencing factors on the development of CSVD in SLE patients. 

Seyed Ali Nabavizadeh¹, Sanjeev Chawla¹, Pei-Hsin Wu¹, Ana Rodriguez-Soto², Erin Englund², Michael C Langham¹, Farzana Sayani¹, Eric Russell¹, and Felix W Wehrli^1
1University of Pennsylvania, Philadelphia, PA, United States, ²University of California San Diego, La Jolla, CA, United States

Silent cerebral infarcts are the most common neurologic injury in patients with sickle cell disease (SCD). In this study, we compared T2 -relaxation under spin tagging (TRUST) and susceptibility-based oximetry (SBO) techniques in a cohort of SCD patients compared to healthy control subjects. We observed opposite trends in oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) in SCD patients compared to controls using TRUST and SBO methods. High OEF measured by TRUST technique lead to very high supraphysiologic CMRO2 values. We conclude that SBO method is more reliable in measuring OEF and CMRO2 in patients with SCD.

Marieke van den Kerkhof^1,2, Jacobus F.A. Jansen^1,2,3, Robert J. van Oostenbrugge^2,4,5, and Walter H. Backes^1,2
1Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, Netherlands, ²School for Mental Health and Neuroscience, Maastricht University, Maastricht, Netherlands, ³Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, ⁴Department of Neurology, Maastricht University Medical Center, Maastricht, Netherlands, ⁵Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Netherlands

Recently developed 2D phase-contrast sequences showed the feasibility of measuring the small lenticulostriate arteries with 7T MRI. However, these vessels are known to be tortuous, and their tortuosity generally increases with aging and in vascular disease. Therefore, we aimed to measure the blood flow velocity not only in one direction, but in three directions, to capture all three velocity components. We found significant components for the other two, less conventional, velocity directions, which resulted in a lower pulsatility index and peak acceleration when comparing to the 1D measurements.

Soroush Heidari Pahlavian^1,2, Xiaoming Bi³, Samantha Ma^1,2, Helena Chui², Danny J.J. Wang^1,2, and Lirong Yan^1,2
1USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States, ²Department of Neurology, University of Southern California, Los Angeles, CA, United States, ³Siemens Medical Solutions USA Inc., Los Angeles, CA, United States

The association between increased cerebrovascular risk factors induced arterial stiffness, and age-related neurodegenerative disorders has been demonstrated in multiple studies. In this study, we evaluated the utility of single-slice two–dimensional (2D) phase-contrast MRI (PC-MRI) to assess arterial stiffness by calculating the carotid pulse wave velocity (cPWV) along the common carotid artery (CCA) and internal carotid arteries (ICA) within a single two-minute scan. Our results demonstrated the feasibility of cPWV measurement using single-slice 2D PC-MRI and indicated a positive correlation between cPWV and arterial damping factor. 2D PC-MRI-measured cPWV holds potential as biomarker to quantify age-related alterations in arterial stiffness.

Rick J van Tuijl¹, Ynte M Ruigrok², Birgitta K Velthuis¹, Irene C van der Schaaf¹, Gabriël J. E. Rinkel², and Jaco J.M. Zwanenburg^1
1Radiology, UMC Utrecht, Utrecht, Netherlands, ²Neurology and Neurosurgery, Rudolf Magnus Institute of Neuroscience, UMC Utrecht, Utrecht, Netherlands

Velocity pulsatility and area distensibility variation along the internal carotid artery (ICA) trajectory were studied with 2D phase-contrast flow measurements (118 subjects;  3T MRI). Results showed a more complicated behavior than just progressive pulsatility decrease along the ICA towards the circle of Willis. The bony carotid canal appears to constrain the distensibility of the ICA, yielding locally increased velocity pulsatility. Velocity pulsatility was significantly higher in men compared to women and increased with ageing. This age-related increase was strongest just proximal to the circle of Willis, indicating reduced damping of the pulsatility along the ICA with age.

Masafumi HARADA¹, Takashi ABE¹, Moriaki YAMANAKA¹, Tomoki MATSUSHITA¹, Yasushi TAKAGI², Yuishin IZUMI³, Marc R Lebel⁴, and Mitsuharu Miyoshi^5
1Department of Radiology, Tokushima University, Tokushima, Japan, ²Department of Neurosurgery, Tokushima University, Tokushima, Japan, ³Department of Neurology, Tokushima University, Tokushima, Japan, ⁴GE Healthcare, Calgary, AB, Canada, ⁵GE Healthcare, Hino, Japan

The purpose of this study was to find a prognostic perfusion parameter to predict the enlargement of acute cerebral infarction. The prognostic parameter of the enlargement ratio (ER) was only mean delay transit time (DT) in all perfusion parameters, and the tendency was different depending on the existence of recanalization or not. DT obtained by multi-delay ASL may become a better prognostic index of acute cerebral infarction than the mismatch area between the infarction core and ischemic penumbra.

Pieter T Deckers¹, Alex A Bhogal², Lisa A van der Kleij², Mathijs BJ Dijsselhof², Kees PJ Braun³, Jeroen CW Siero², and Albert Van der Zwan^1
1Neurosurgery, UMC Utrecht, Utrecht, Netherlands, ²Radiology, UMC Utrecht, Utrecht, Netherlands, ³Pediatric Neurology, UMC Utrecht, Utrecht, Netherlands

Measuring the cerebral blood flow and cerebrovascular reactivity is vital in the preoperative assessment of moyamoya patients. We propose a combination of continuous multiband BOLD-MRI and multidelay ASL-MRI with acetazolamide as a comprehensive multi-modal alternative for the current commonly used PET-CT method. Eight female patients (age 8-41) were scanned at 3T with a ±30 min scan protocol, which is also suitable for patients scanned under general anesthesia. The obtained reactivity maps of the two sequences showed good agreement for severity and location of hemodynamic impairment. This accessible MRI method is directly suitable for routine clinical evaluation of moyamoya patients.

Kentaro Akazawa¹, Masashi Yasuike², Koji Sakai¹, Chisa Bamba¹, Jun Tazoe¹, Nagara Tamaki¹, and Kei Yamada^1
1Radiology, Kyoto Prefectural University of Medicine, Kyoto, Japan, ²Radiology, Kyoto Yamashiro General Medical Center, Kizugawa, Japan

The proximal internal carotid artery (pICA) stenosis is an important cause of ischemic cerebrovascular disease. We evaluated the predicting power to identify unilateral pICA stenosis based on the intracranial 3D time of flight MR angiography (MRA) with multi-slab acquisition used in daily clinical practice by a quantitative assessment of the asymmetry in the middle cerebral artery (MCA). The result revealed that the MCA volume ratio of subjects were significantly lower than controls and the accuracy, sensitivity and specificity to identify subjects were 0.71, 0.71 and 0.88. The quantitative evaluation on intracranial MRA may provide additional information to unilateral pICA stenosis.

Xiaoyue Ma^1,2, Yan Wang^1,2, Fengshan Yan^1,2, Xianchang Zhang³, Lirong Yan⁴, and Meiyun Wang^1,2
1Radiology, Henan Provincial People's Hospital, Zhengzhou, China, ²Henan Key Laboratory of Neurological Imaging, Zhengzhou, China, ³MR Collaboration, Siemens Healthcare Ltd., Beijing, China, ⁴Stevens Neuroimaging Informatics Institute, Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States

This study aimed to explore the clinical value of random vessel-encoded arterial spin labeling (rVE-ASL) in evaluating the collateral status as well as its association with clinical outcomes in patients with ischemic stroke. Results suggested that the rVE-ASL findings were consistent with DSA/CTA findings in characterizing collateral flows and poor collateral flows evaluated by rVE-ASL were associated with poor outcomes. The rVE-ASL could be a potentially useful tool to assess the cerebral collateral circulation in patients with ischemic stroke and predict the clinical outcome.

Bing Tian¹, Xia Tian², Zhang Shi², Qi Liu², and Jianping Lu^2
1Radiology, Changhai hospital, Shanghai, China, ²Changhai hospital of Shanghai, Shanghai, China

HR-MRI provides important insights of assessing both vessel lumen and wall inintracranial artery stenosis disease.

Xinyu Wang¹, Xinyi Wang², and Weiqiang Dou^3
1Medical imaging, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan，Shandong, China, ²Medical imaging, The First Affiliated Hospital of Shandong First Medical University, Jinan，Shandong, China, ³MR Research China, GE Healthcare, Beijing, China

In this study, the main purpose was to explore the clinical value of territory arterial spin labeling （T-ASL） in assessing perfusion changes after unilateral middle cerebral artery （MCA）recanalization. We included 15 patients diagnosed by Digital Substraction Angiography（DSA） with unilateral MCA stenosis, T-ASL examination was performed before and after surgery. Patients showed significantly different reperfusion areas between pre- and post-operations, and some had hyperperfusion displacement in the major cerebral arterial blood supply area. Therefore, T-ASL technique can be used as a valuable method to evaluate the effect of vascular recanalization accurately.

Hongwei Zhou¹, Dezheng Kong¹, and Tianjing Zhang^2
1Jilin University First Hospital, Changchun, China, ²Philips healthcare, Guangzhou, 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

Koji Fujimoto¹, Yasutaka Fushimi², Takeshi Funaki³, Satoshi Nakajima², Yusuke Yokota², Sonoko Oshima², Sayo Otani², Azusa Sakurama², Krishna Wicaksono Pandu², Tomohisa Okada¹, and Kaori Togashi^2
1Human Brain Research Center, Graduate School of Medicine, Kyoto University, Kyoto, Japan, ²Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Kyoto, Japan, ³Department of Neurosurgery, Kyoto University, Kyoto, Japan

One subject with Moyamoya disease was scanned with radial vibe sequence. GRASP reconstruction was performed using different number of spokes/frame. ROI-based analysis performed to compare the maximum slope for each ROI placed in the vessels showed that the faster imaging gave the larger slope, but the blurring at the corner of TIC is seen at the higher temporal resolution. By using images with 5 spokes/frame, voxel-by-voxel analysis could create the arrival map and the maximum slope map.

Hong-Wei Zhou¹, Dezheng Kong¹, and Tianjing Zhang^2
1Jilin University First Hospital, Changchun, China, ²Philips healthcare, Guangzhou, 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.

Balazs Orzsik¹, Iris Asllani², Mara Cercignani², and Neil Harrison^3
1University of Sussex, Brighton, United Kingdom, ²Department of Neuroscience BSMS, University of Sussex, Brighton, United Kingdom, ³CUBRIC, University of Cardiff, Cardiff, United Kingdom

Cerebral blood flow during awake and  pharmacologically induced sleep was investigated with arterial spin labeling imaging in  healthy young volunteers. Participants were scanned after a good night sleep and in a separate session after 24h sleep deprivation. Participant received 10mg Zolpidem after the sleep deprivation to maximize sleep in the scanner. There was a significant reduction in cerebral blood flow in the sleep condition compared to awake. The most prominent changes were observed in the Thalamus, cerebellum, posterior cingulate gyrus, these areas stayed significant after family wise error correction at a cluster level. 

Liu Xiaoming¹, Kong Xiangchuang¹, Lei Ziqiao¹, Zhang Xiaoyong², and Liu Dingxi^1
1Departments of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China, ²MR Collaborations, Siemens Healthcare Ltd, Shenzhen, China

Contrast-enhanced magnetic resonance angiography (CE-MRA) is the main modality used for assessing carotid artery stenosis in the vessel lumen, but limited to the susceptibility artifact, which would result in artifactual stenosis of artery adjacent to the subclavian vein on the injection side of contrast medium. This study aims to explore the quantitative influence of different injected flow rates of contrast medium on the susceptibility effect in the subclavian arterial image of CE-MRA on a 3T MR scanner. The result indicated that the magnetic susceptibility artifact can be reduced by improving the injection speed of contrast agent

Haben Berhane¹, Maria Aristova², Yue Ma², Michael Markl², and Susanne Schnell^2
1Lurie Children's Hospital of Chicago, Chicago, IL, United States, ²Northwestern University, Chicago, IL, United States

We developed and validated a convolutional neural network for the fully automated 3D segmentation of the cerebral vasculature from 4D flow MRI for rapid flow analysis. Using 53 4D flow MRI scans, including 16 patients with intracranial atherosclerotic disease, we trained and tested our CNN using 10-fold cross validation. We assessed net flow and peak velocities across all of the major arteries and veins of the intracranial vasulature between automated and manually performed analysis. Across all metrics and regions, we found the automated segmentation showed excellent agreement with the manual, while taking a fraction of the time to perform.

Francesca Inglese¹, Myriam G. Jaarsma-Coes¹, Gerda M. Steup-Beekman², Tom Huizinga², Mark A. van Buchem¹, Itamar Ronen¹, and Jeroen de Bresser^1
1Department of Radiology, Leiden University Medical Center, Leiden, Netherlands, ²Department of Rheumatology, Leiden University Medical Center, Leiden, Netherlands

Systemic Lupus Erythematosus (SLE) often presents with neuropsychiatric (NP) symptoms. These symptoms can be directly associated with SLE (NP-SLE) or not (non-NP-SLE). We investigated whether white matter hyperintensity (WMH) features (such as type, volume and shape) may contribute to the diagnosis of NP-SLE. Patients with NP-SLE more often had deep WMH (DWMH) compared to patients with non-NP-SLE. There were no significant differences in WMH volume and shape features between NP-SLE patients compared to non-NP-SLE patients. In conclusion, NP-SLE patients more often had DWMH compared to non-NP-SLE patients and this may help in the diagnostic process of NP-SLE.

YuTing Li^1
1Department of Radiology, Tangdu Hospital， Fourth Military Medical University, Xian，ShanXi province, China

Our purpose is to find the cerebral neurovascular coupling altered in patients with narcolepsy.It was reported that Multifunctional MRI can explore the relationship between cerebral vascular perfusion and neural activity. And we found decreased NVC in right and left precentral gyrus, left occipital gyrus, left postcentral gyrus, left fusiform gyrus and right amygdala

Dushyant Kumar¹, Rajesh Mishra¹, Govind Maurya¹, Chahat Kumar², Priyanka Bhagat², Padma Srivastava², and Rama Jayasundar^3
1Department of NMR, All India Institute of Medical Sciences, New Delhi, India, ²Department of Neurology, All India Institute of Medical Sciences, New Delhi, India, ³DEPARTMENT OF NMR, ALL INDIA INSTITUTE OF MEDICAL SCIENCES, NEW DELHI, India

This MRI study has evaluated for the first time, the structural changes effected by yoga in post-stroke (ischemic) recovery. Patients (n=6) with deficits practiced Hatha yoga for one hour daily for six months under the supervision of certified yoga trainers. Pre- and 6 months post-yoga intervention assessment involved assessment of NIHSS score and 3D-T1 MRI at 3T MR. Results show individual patients’ positive response to yoga reflected in the significantly reduced NIHSS scores, and in the increased gray matter volume in some areas in brain.

Wen-Ching Liu¹, Timothy Linghau Chen², Kyler Shin², and David Wang^3
1Radiology, OSF Saint Francis Medical Center, Peoria, IL, United States, ²Medicine, University of Illinois College of Medicine at Peoria, Peoria, IL, United States, ³Neurology, Barrow's Neurological Institute, Phoenix, AZ, United States

In order to establish the standard brain regional temperatures in normal and healthy people, we initiated a weekly MR spectroscopy quality assurance program, developed the single voxel MRS thermometry calibration  curve with a MRS phantom and scanned 10 normal and healthy right handed men.  Five region of interests, hypothalamus, cerebellum, thalamus, frontal lobe, and occipital lobe are selected.  Interestingly we found a non-uniform temperature distribution in these ROIs.  The hypothalamus and thalamus have the highest temperature while cerebellum has the lowest.   

Yiwei Che¹, Yanwei Miao¹, Yuhan Jiang¹, Peipei Chang¹, Bingbing Gao¹, Qingwei Song¹, Ailian Liu¹, Jiazheng Wang², and Yanling Wu^2
1Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China, ²Philips Healthcare, Beijing, China

End-stage renal disease (ESRD) has become risk factor for vascular disease, stroke and cognitive dysfunction, and the white matter lesions may be associated with these adverse outcomes. Silent white matter alterations may occur in the earlier stages, whereas conventional MR imaging may not be found, This study aim to detect subtle white matter alterations in patients with ESRD through diffusion tensor imaging (DTI). DTI can reflect early occult white matter damage in ESRD patients.

Huiying Wang^1,2, Chao Chai³, and Shuang Xia^3
1Radiology, Tianjin First Central Hospital；Tianjin Medical Imaging Institute, Tianjin,, Tianjin, China, ²Qinghai University Affiliated Hospital, QingHai, China, ³Tianjin First Central Hospital；Tianjin Medical Imaging Institute, Tianjin,, Tianjin, China

This study aimed to demonstrate the longitudinal changes of brain volume in hemodialysis, and the relationship between brain volume and cognitive function. Thirty-three hemodialysis patients and thirty healthy controls (HCs) were recruited to this study. All patients underwent MR examinations to evaluate baseline and follow-up brain volume. Compared to the HCs, patients showed decreased gray matter (GM) volume and white matter (WM) volume. Compared to baseline patients, follow-up patients showed decreased GM volume and WM volume. The decreased left caudate volume was positively correlated with reduced neuropsychological scores in patients. Brain atrophy occurred in hemodialysis patients, leading to neurocognitive impairment.

Huiying Wang^1,2, Chao Chai¹, and Shuang Xia^1
1Tianjin First Central Hospital；Tianjin Medical Imaging Institute, Tianjin,, Tianjin, China, ²Qinghai University Affiliated Hospital, QingHai, China

This was the first study focused on longitudinal CBF changes of ESRD patients with regular hemodialysis. This study used noninvasive pulsed arterial spin labeling technique to provide evidence for clinical evaluation of the changes in cerebral hemodynamics in hemodialysis patients.

DUN DING^1,2, Xueying Ma^2,3, Peng Li⁴, Pan Zhang⁵, and Ming Zhang^6
1The Second affiliated hospital of Xi'an JiaoTong Uuniversity, Xi'an, China, ²The second affiliated hospital of Xi 'an JiaoTong Uuniversity, Xi'an, China, ³The First affiliated hospital of Neimenggu medical Uuniversity, Hohhot, China, ⁴The first affiliated hospital of Xi'an JiaoTong Uuniversity, Xi'an, China, ⁵The second affiliated hospital of Xi'an JiaoTong Uuniversity, Xi'an, China, ⁶The First affiliated hospital of Xi'an JiaoTong Uuniversity, Xi'an, China

Uremic Restless Leg Syndrome (uRLS) is an uncomfortable complication of inferior limbs and involuntary movements in patients with end-stage renal disease during maintenance of insular, especially during sleep breaks. As an important information processing and processing area, the insular  play an important role in sensory, motor metabolism, sensorimotor information processing,and mood regulation. Through this study,We found that the altered morphology of post insular was revealed in uRLS patients, abnormal sensorimotor activities in patients with RLS is closely associated with reduced functional connectivity of insular-S1.Low hemoglobin level was the most important risk factor related to brain functional connectivity feature.

Hua-Jun Chen¹, Tian-Xiu Zou¹, and Nao-Xin Huang^1
1Fujian Medical University Union Hospital, Fuzhou, China

Minimal hepatic encephalopathy (MHE) is characterized by a series of cognitive impairments. Thalamus is a critical pathological node of MHE. Thus, we  applied probabilistic tractography to investigate the thalamic fiber pathway alterations in MHE, for the first time.  The thalamic structural connection was disturbed in MHE patients (reflected by decreased CS/FA and increased MD/AD/RD). Abnormal thalamic connection primarily involved prefrontal cortex, sensorimotor cortex, parietal cortex, medial temporal cortex and hippocampus, and striatum. Thalamic connectivity abnormalities deteriorated with disease progression and correlated with patients’ impaired neuropsychological performance. The disturbed thalamic connectivity can serve as biomarker for diagnosis of MHE.

Yi-Fang Wu¹, Vincent Chin-Hung Chen^2,3, Yuan-Hsiung Tsai⁴, and Jun-Cheng Weng^1,3,5
1Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan, ²School of Medicine, Chang Gung University, Taoyuan, Taiwan, ³Department of Psychiatry, Chang Gung Memorial Hospital, Chiayi, Taiwan, ⁴Department of Diagnostic Radiology, Chang Gung Memorial Hospital, Chiayi, Taiwan, ⁵Medical Imaging Research Center, Institute for Radiological Research, Chang Gung University and Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan

Adjuvant chemotherapy has been associated with cognitive impairment among a subgroup of breast cancer patients. A limited number of studies have observed the relationship between adjuvant chemotherapy, post-traumatic stress disorder (PTSD) and structural brain changes. Therefore, we employed voxel-based morphometry (VBM) and vertex-wise shape analyses to find the differences in brain volume and shape among pre- and post-chemotherapy breast cancer patients and healthy subjects. Our results showed gray and white matter volume alterations in frontal and temporal brain regions among each group. We also observed the change of shape in the limbic system.

Benjamin Sinclair^1,2, John-Paul Nicolo^1,2,3,4, David Wright¹, Bradford Moffat⁵, Andrew Neale^1,2,3,4, Nian Yu^6,7, Elaine Lui^8,9, Patricia Desmond^8,9, Rebecca Glarin^8,9, Kathryn Davis¹⁰, Ravi Prakash Nanga¹¹, Ravinder Reddy¹¹, Farshid Sepehrband¹², Bernard Yan^3,4, Scott Kolbe¹, Patrick Kwan^1,2,3,4, Terence J O'Brien^1,2,3,4, and Meng Law^1,6
1Department of Neuroscience, Monash University, Melbourne, Australia, ²Department of Neurology, Alfred Hospital, Melbourne, Australia, ³Department of Neurology, Royal Melbourne Hospital, Melbourne, Australia, ⁴Department of Medicine, University of Melbourne, Melbourne, Australia, ⁵Melbourne Node of the National Imaging Facility, Department of Radiology, University of Melbourne, Melbourne, Australia, ⁶Department of Radiology, Alfred Hospital, Melbourne, Australia, ⁷Department of Radiology, The Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, China, ⁸Department of Radiology, Royal Melbourne Hospital, Melbourne, Australia, ⁹Department of Radiology and Medicine, University of Melbourne, Melbourne, Australia, ¹⁰Penn Epilepsy Center, Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, PA, United States, ¹¹Center for Magnetic Resonance & Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, ¹²USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States

In this pilot study we test the hypothesis that glutamate levels post-stroke are influenced by glia-lymphatic clearance pathways in the brain. Excess glutamate can be neurotoxic, and stroke is associated with focally elevated gluatamate concentrations. Perivascular spaces have recently been found to play a role in waste clearance in the brain, and often become enlarged when compromised. We used Chemical Exchange Saturation Transfer (CEST) imaging at 7T to characterise glutamate concentrations, and found that they were moderately positively correlated with scores of enlarged pervivascular spaces. 

Skylar E Johnson¹, Colin McKnight¹, Spencer Waddle¹, Maria Garza¹, Lori C Jordan^1,2,3, Daniel O Claassen³, and Manus J Donahue^1,3,4
1Radiology and Radiological Sciences, Vanderbilt University School of Medicine, Nashville, TN, United States, ²Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, United States, ³Neurology, Vanderbilt University School of Medicine, Nashville, TN, United States, ⁴Psychiatry, Vanderbilt University School of Medicine, Nashville, TN, United States

The goal of this study is to investigate whether choroid plexus (CP) activity, quantified as perfusion measured from arterial spin labeling, is altered in patients with cerebrovascular disease. Cohorts comprised arterial intracranial stenosis (n=56), sickle cell disease (n=41), and healthy controls (n=31). In controls and stenosis patients, CP and gray matter perfusion were similar; in patients with sickle cell disease, CP-to-gray matter perfusion was reduced (p<0.001) relative to other cohorts. This finding is discussed in the context of how efficient CSF perivascular flow surrounding dilated arterial spaces may require reduced CSF production activity to subserve waste clearance.

Daniel D Borup¹, Sandeep K Ganji², Petrice Mostardi Cogswell¹, and James G Pipe^1
1Radiology, Mayo Clinic, Rochester, MN, United States, ²Philips Healthcare, Gainesville, FL, United States

The use of a 2D golden-angle spiral trajectory is demonstrated for the measurement of CSF flow at the cerebral aqueduct and foramen magnum. The results compare favorably with a standard cardiac-gated Cartesian scan when retrospectively binned using the cardiac waveform. The spiral data also show variation in the CSF flow waveforms across the respiratory cycle and can be reconstructed as a time-resolved image series for spectral analysis of the flow dynamics.

Farshid Sepehrband¹, Samantha Ma², Jeiran Choupan², Sook-Lei Liew², and Arthur W Toga^2
1Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, USC, Los Angeles, CA, United States, ²USC, Los Angeles, CA, United States

Imaging of the perivascular spaces (PVS) is of growing interest, especially due to its involvement in brain clearance and blood-brain barrier exchange [1]–[3]. PVS mapping is often limited to macroscopic PVS (>1mm), which limits the study of subtle morphological PVS alteration that is expected to occur in submillimeter resolution. Here we show the advantage of ultra-high field imaging for detailed quantification of PVS in vivoand noninvasively. 

Farshid Sepehrband¹, Giuseppe Barisano², Hyun-Joon Yang², Jeiran Choupan², and Arthur W Toga^2
1Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, USC, Los Angeles, CA, United States, ²USC, Los Angeles, CA, United States

Perivascular space (PVS), also known as Virchow-Robin space, is a pial-lined, fluid-filled structure that surrounds vessels in the cerebral cortex [1], [2], and occupies a large portion of the cerebral tissue. While PVS mapping becomes more clinically relevant, separation of PVS from white matter hyperintensities (WMH) make it challenging to map PVS on clinical data. Here we present a semi-supervised multi-modal approach to extract both PVS and WMH using T1w and FLAIR image modalities automatically. We also evaluated multi-site, multi-vendor reliability of the technique. 

Jun-Hee Kim¹, Seung Hong Choi², and Sung-Hong Park^1
1Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea, Republic of, ²Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea, Republic of

Imaging in-vivo movement of cerebrospinal fluid can be applied not only to diagnose the CSF disorders like hydrocephalus, but also to visualize and evaluate the CSF circulation for the clearance. In this study, we used single phase and multiphase alternate ascending/descending directional navigation (ALADDIN) to image the overall, dynamic CSF flow pattern. Single phase ALADDIN showed overall bulk flow of CSF, and multiphase ALADDIN showed dynamically‑tracked signals of labeled CSF. We expect that ALADDIN can be applied to study CSF circulation and clearance disorders.

Andrey Tulupov¹ and Olga Bogomyakova^1
1Laboratory of neuroscience, The Institute International Tomography Center of the Russian Academy of Sciences, Novosibirsk, Russian Federation

In this work we study the most momentous disturbances of hemo- and cerebrospinal fluid dynamics in patients with idiopathic intracranial hypertension (IIH) and idiopathic non-obstructive hydrocephalus (INH). It is shown that ICC, AVD and PI are perspective diagnostic criteria for functional brain diseases, associated with disturbances in hemo- and cerebrospinal fluid dynamics.

Ruiting Zhang¹, Peiyu Huang¹, and Minming Zhang^1
1The Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, China

We aimed to investigate whether and how venous disruption was related to white matter damage in cerebral small vessel disease(CSVD) patients. SWI was used to investigate venous disruption. Free water elimination DTI model was used to analyze interstitial fluid fraction(fraction of free water, fFW) and white matter integrity(tissue fractional anisotropy, FAt). In 104 CSVD patients, venous disruption was associated with FAt, and the effect was mediated by fFW. This relationship was independent of arterial cerebral blood flow. In conclusion, we discovered the venous disruption - increased interstitial fluid - white matter damage link in CSVD patients.

Matthew C Murphy¹, Petrice M Cogswell¹, Joshua D Trzasko¹, Armando Manduca¹, Matthew L Senjem¹, Fredric B Meyer¹, Clifford R Jack, Jr.¹, Richard L Ehman¹, and John Huston, III^1
1Mayo Clinic, Rochester, MN, United States

Normal pressure hydrocephalus (NPH) is a neurological disorder characterized by abnormal gait, cognitive decline, and urinary incontinence. The hypothesized role of biomechanics in NPH pathogenesis supports a potential role for magnetic resonance elastography (MRE) in diagnosis and prediction of response to therapy. In this study, MRE was performed in 13 NPH patients before and after shunt placement to test the hypothesis that treatment would reverse NPH-driven changes to the brain’s mechanical properties. We observed that increased stiffness and decreased damping ratio at the vertex were largely reversed by shunting, while periventricular white matter softening was unaffected.

Szu-Hsuan Yu¹, Wei-Chi Li¹, Jiun Wei Chen², Hong-Yuan Mark Liao², Feng-Chi Chang³, Chih-Ping Chung^4,5,6, Jong-Ling Fuh^6,7,8, and Li-Fen Chen^1,8,9,10
1Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan, ²Institute of Information Science, Academia Sinica, Taipei, Taiwan, ³Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, ⁴Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan, ⁵Department of Neurology, National Yang Ming University, Taipei, Taiwan, ⁶Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, ⁷Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan, ⁸Brain Research Center, National Yang-Ming University, Taipei, Taiwan, ⁹Integrated Brain Research Unit, Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan, ¹⁰Institute of Biomedical Informatics, National Yang-Ming University, Taipei, Taiwan

The contributions of blood vessels impairment to dementia are increasingly recognized, but the relationships between microbleeds and blood–brain barrier (BBB) in dementia patients are still unclear. We recruited subjects with Alzheimer’s disease (AD), mild cognitive impairment (MCI), subjective cognitive decline (SCD), and healthy control (HC). The susceptibility weighted images and dynamic contrast-enhanced images were acquired to detect cerebral microbleeds and to estimate BBB integrity. Our results showed high risk with BBB breakdown in AD patients with cerebral microbleeds, which suggests the association between neurovascular unit dysfunction and blood vessel impairment may be a biomarker for the progression of dementia.

Carles Javierre Petit¹, Ashish A. Tamhane², Arnold M. Evia¹, Nazanin Makkinejad¹, Gady Agam³, David A. Bennett², Julie A. Schneider², and Konstantinos Arfanakis^1,2
1Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States, ²Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, United States, ³Computer Science, Illinois Institute of Technology, Chicago, IL, United States

Enlarged perivascular spaces (EPVS) are common in aging and have been linked to increased risk of stroke, lower cognitive function, and vascular dementia. However, the neuropathologic correlates of EPVS, as well as the contributions of EPVS to cognition, are not well understood. In this work, we first developed a deep-learning algorithm for automatic segmentation and full quantification of whole brain and regional EPVS, and then studied the neuropathologic correlates of EPVS as well as the contributions of EPVS on cognition in a large community-based cohort of older adults.

Arun Venkataraman¹, F. Vankee Lin², Rashid Deane³, and Jianhui Zhong^4
1Physics, University of Rochester, Rochester, NY, United States, ²Neurology, University of Rochester, Rochester, NY, United States, ³Neuroscience, University of Rochester, Rochester, NY, United States, ⁴Imaging Sciences, University of Rochester, Rochester, NY, United States

Amnestic MCI (aMCI) is a prodromal stage to Alzheimer's Disease (AD), with around 10-15% of patients with aMCI converting to AD per year. It is unclear what mechanisms are involved in the initiation and progression through aMCI. One hypothesis involves the “glymphatic” system, a hypothesized pathway mediated by Cerebrospinal Fluid (CSF) flow that is essential to clearing toxins and cellular debris from the brain. In this study, we analyze how CSF flow dynamics are altered in subjects with aMCI. Overall, we found that lower flow in the 4th ventricle is linked with increased disease burden.

Tabitha J Manson^1,2, Xingfeng Shao³, Danny JJ Wang³, Matthias Günther^4,5, Lynette Tippett^2,6,7, Michael Dragunow^2,7,8, David L Thomas^9,10, Vinod Suresh^1,11, and Catherine Morgan^2,6,7
1Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand, ²Brain Research New Zealand, Auckland, New Zealand, ³Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States, ⁴Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany, ⁵Faculty 01 (Physics/Electrical Engineering), University Bremen, Bremen, Germany, ⁶School of Psychology, University of Auckland, Auckland, New Zealand, ⁷Centre for Brain Research, University of Auckland, Auckland, New Zealand, ⁸Department of Pharmacology, University of Auckland, Auckland, New Zealand, ⁹Dementia Research Centre, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom, ¹⁰Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, UK, London, United Kingdom, ¹¹Department of Engineering Science, University of Auckland, Auckland, New Zealand

Blood-brain barrier (BBB) dysfunction has been found in multiple neurodegenerative conditions, including mild cognitive impairment (MCI) and Alzheimer’s disease (AD). However recent concerns on the repeated use of Gadolinium based contrast agents (GBCAs), prompted us to investigate alternative, non-invasive methods for measuring BBB function. Both diffusion-weighted (DW) and multi-echo (ME) ASL was implemented at 3T to determine water transfer rates (kw) in the brain in MCI and early AD participants. We found kw to be lower in the cognitively impaired group, compared to controls, with both modalities, suggesting that these techniques may provide a marker of early AD pathology.

Tine Arts¹, Hilde van den Brink², Anna Kopczak³, Martin Dichgans³, Jeroen Hendrikse¹, Jeroen Siero^1,4, Jaco Zwanenburg¹, and Geert Jan Biessels^2
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, ²Neurology, University Medical Center Utrecht, Utrecht, Netherlands, ³Institute of Stroke and Dementia Research, Munich, Germany, ⁴Spinoza Centre for Neuroimaging, Amsterdam, Netherlands

CADASIL is a monogenic form of cerebral small vessel disease that leads to ischemic brain lesions at mid-adult age. We studied arterial perforator blood flow velocity and pulsatility in CADASIL patients and matched controls. We found significantly lower velocity and higher pulsatility in the basal ganglia and in normal appearing white matter (NAWM) of the centrum semi-ovale (CSO) in patients compared to controls. Within patients, no differences in velocity and pulsatility were found between CSO NAWM and white matter hyperintensities. This shows that small vessel disease in CADASIL patients is reflected in abnormal small vessel function also beyond lesioned areas. 

Yeerfan Jiaerken^1,2 and Zhang Minming^1
1Second Affiliated Hospital of Zhejiang University, School Of Medicine, hangzhou, China, ²UNC Chapel Hill, chapel hill, NC, United States

We investigated how dilated perivascular space (dPVS) affects water drainage in surrounding tissue and whether there is any distance-related pattern of water distribution around dPVS. We found that The isotropic diffusing water content was higher within dPVS, compared to contralateral normal white matter, and the CSVD subjects had higher within-dPVS water content than healthy subjects, and dPVS showed different distance-related pattern in healthy subjects and subjects with severe CSVD, suggesting dPVS played different roles in healthy subjects and CSVD.