Ziyu Meng¹, Tianyao Wang², Bin Bo¹, Rong Guo^3,4, Yudu Li^3,4, Yibo Zhao^3,4, Xin Yu⁵, Zhi-Pei Liang^3,4, and Yao Li^1
1School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China, ²Radiology Department, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China, ³Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States, ⁴Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, ⁵Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States

Characterization of the underlying pathophysiological changes associated with edema progression is essential for treatment guidance in ischemic stroke. ¹H-MRSI and quantitative T₂ mapping can acquire image markers related to the physiological states of brain tissues. This study investigated the neurometabolite changes in relation to the development of vasogenic edema in ischemic stroke patients, using fast high-resolution 3D MRSI and T₂ mapping techniques. Our results showed that neurometabolite concentrations were strongly correlated with T₂ values within ischemic lesion of stroke patients and integrated T₂ and neurometabolite biomarkers improved the prediction accuracy of stroke patients' clinical outcome.

Zhe Zhang^1,2, Qingle Kong³, Jing Jing^1,2, and Yongjun Wang^1,2,4
1Tiantan Neuroimaging Center of Excellence, Beijing Tiantan Hospital, Capital Medical University, Beijing, China, ²China National Clinical Research Center for Neurological Diseases, Beijing, China, ³MR Collaboration, Siemens Healthineers Ltd., Beijing, China, ⁴Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China

The impairment of microvessels can lead to neurologic diseases such as stroke and vascular dementia. The imaging of perforating arteries requires an extremely high resolution due to their small caliber size. In this study, we optimized the parameters of compressed sensing (CS) TOF-MRA to achieve isotropic 0.2 mm lenticulostriate artery (LSA) images within 10 minutes at 7T. More LSA stems and branches were delineated in CS TOF images compared with conventional TOF images. CS TOF-MRA can be a state-of-the-art method for detecting microvasculopathies of cerebral vascular diseases.

Hirohito Kan^1,2, Kyosuke Mizuno³, Masahiro Takizawa⁴, Masashi Shimohira⁵, Tatsuya Kawai⁵, Tositaka Aoki⁶, Satoshi Tsubokura⁶, and Harumasa Kasai^6
1Department of Integrated Health Scieneces, Nagoya University Graduate School of Medicine, Nagoya, Japan, ²Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan, ³Department of Radiology, Nagoya City University Hospital, Nagoya, Japan, ⁴FUJIFILM Healthcare Corp., Tokyo, Japan, ⁵Department of Radiology, Nagoya City University Graduate School of Medical Scieneces, Nagoya, Japan, ⁶Nagoya City University Hospital, Nagoya, Japan

To develop and validate the non-contrast time-resolved MR angiography (NC TR-MRA) with consecutive beam pulse with variable saturation flip angle method, we performed a phantom study using steady flow and the volunteer study targeted to the pulmonary artery. The length of visualized flow signals was exhibited proportional to the number of beam saturation pulses in the phantom study. In human study, the visualization range of the pulmonary artery was also extended with increasing the number of beam pulses. The novel consecutive beam pulse with variable saturation flip angle method can depict blood vessels in each flow phase.

Qi Meng¹, Chao Jiang², Keqiang Zhao², Huabin Zhang¹, Hongliang Zhao³, Xihai Zhao⁴, Weiwei Wu², and Zhuozhao Zheng^3
1Department of Ultrasound, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China, ²Department of Vascular Surgery, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China, ³Department of Radiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China, ⁴Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China

It has been shown that about 30%-70% of the patients underwent carotid artery stenting (CAS) suffered from perioperative hemodynamic instability (HI) characterized by transient hypotension and bradycardia. This study investigated the association between vulnerable plaque characteristics on MR vessel wall imaging and HI during CAS. We found that patients in HI group had significantly larger wall area and total vessel area, higher prevalence of intraplaque hemorrhage and vulnerable plaque, and larger volume of lipid-rich necrotic core (LRNC) of carotid plaque compared to those in non-HI group. The volume of LRNC and presence of vulnerable plaque could effectively predict HI.

Dongkyu Lee¹, Thi Thuy Le¹, Geun Ho Im¹, and Seong-Gi Kim^1
1Center for Neuroscience Imaging Research, Institute for Basic Science, Suwon, Korea, Republic of

Noninvasive perfusion mapping is important to determine perfusion changes due to molecular and neuropathological modifications as well as pharmaceutical interventions. Here, we adopted a dynamic BOLD-MRI method for quantifying whole brain perfusion, such as cerebral blood volume (CBV) and cerebral blood flow (CBF) without the use of exogenous contrast agents in mice. High-resolution perfusion maps allow us to determine regional perfusion values and cortical depth-dependency. The proposed technique is non-invasive and repeatable with every <1 min temporal resolution and can combine with evoked fMRI studies for determining a neural activity-induced quantitative change of perfusion parameters.

Kazuo Kodaira¹, Michinobu Nagao², Masami Yoneyama³, Mana Kato¹, Takumi Ogawa¹, Yutaka Hamatani¹, Isao Shiina¹, Yasuhiro Goto¹, and Shuji Sakai^2
1Department of Radiological Services, Tokyo Woman's Medical University Hospital, Tokyo, Japan, ²Department of Diagnostic imaging & Nuclear Medicine, Tokyo Woman's Medical University Hospital, Tokyo, Japan, ³Philips Japan, Tokyo, Japan

Conventional whole-heart-coronary-magnetic-resonance-angiography (WHC-MRA) using NAV has a limitation of long scan time. Single-breath-hold-multi-shot-gradient-EPI can significantly reduce scan time of WHC-MRA, but it may be difficult depending on the gradient-spec of MRI-system. 3D-turbo-field-echo-planar-imaging (TFEPI) with Compressed-SENSE (C-SENSE) has the possibility to solve these problems. However, it is yet not applied for WHC-MRA. C-SENSE is suitable for subjects with a high sparse such as vessels, and can accelerate scan time of WHC-MRA while ensuring image quality. We propose a new combination of TFEPI with C-SENSE for single-breath-hold WHC-MRA, and examine image quality and scan time in comparison to the conventional methods.

Junjing He¹, Xiuzheng Yue², Gang Zhang¹, Wei Xing¹, Tingting Li¹, Yufu Hu¹, and Yuhan Wang^1
1Department of Magnetic Resonance, The First Affiliated Hospital of Henan University of CM, Zhengzhou, China, ²Philips Healthcare, Beijing, China

This study explores impact factors of the quality of 3.0T non-contrast agent magnetic resonance coronary angiography (MRCA), and uses an objective standard for assessing the image quality. A retrospective review was conducted on 72 patients who successfully completed 3.0T MRCA, and the correlation between their image quality and their clinical data, scan sequence, parameter settings, imaging technology and other factors were analyzed.The study found that BMI and respiratory motion were the key factors that affect the quality of non- contrast agent coronary MRA on 3.0T MRI. The mDixon-TFE imaging method can be used for MRCA as a routine scanning sequence. 

FENG XIONG¹, Yang Wu¹, Longyan Zhang¹, Xiaojing Ma¹, Ke Yu¹, Peng Sun², and Haixia LI^2
1Wuhan Asia General Hospital, WuHan, China, ²Philips Healthcare, Beijing, China

The whole-heart coronary MRA with compressed sensing (CS) technique is a novelly noninvasive, contrast agent-free, and radiation-free technique for evaluating coronary artery disease^[2] [3].Patients with atrial fibrillation have irregular heartbeat, which brings uncertainty to the coronary MRA image quality. Results of this study indicated that there was no statistical difference in coronary artery image quality with CS acceleration factors of 2, 4, 6 between sinus rhythm and atrial fibrillation patients, which suggested that whole-heart coronary MRA with CS technique could also be applied inpatients with atrial fibrillation.

Yunjie Liao¹ and Chen Thomas Zhao^2
1Department of Radiology, the Third Xiangya Hospital, Central South University, Changsha, China, ²Philips Healthcare, Guangzhou, China

Spinal artery imaging has long been difficult in clinical detection and assessment of spinal vascular lesions, due to its anatomical complexity and very small diameter. Compared with DSA and CT, CE-MRA technology has the advantages of safety, noninvasive and radiation free. Traditional MR sequences, such as TOF and PC, perform poorly with lower SNR. Here, accuracy of B-TFE and 3D T1-FFE sequences were compared to provide radiologists a better choice in the spinal artery scenario. The results indicated that 3D T1-FFE would be preferred than B-TFE. And B-TFE should be used merely when patients are sensitive to contrast media

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

This study mainly explored the feasibility of high-resolution vascular wall magnetic resonance imaging（HR-VW-MRI）in evaluating the treatment effect for patient with middle cerebral artery (MCA) recanalization. We included 21 patients with MCA stenosis diagnosed by DSA. All patients were treated with SeQuent Please drug-coated balloon recanalization and performed with HR-VW-MRI examination. Decreased responsible plaque area, length, enhancement index and lumen stenosis degree were found in MCA postoperatively. Additionally, the lumen stenosis degree evaluated by HR-VW-MRI was highly correlated with DSA. Therefore, HR-VW-MRI could be used as a valuable method to diagnose the effect of vascular recanalization.

Boyu Zhang¹, Zidong Yang¹, Bei Wang¹, Yajing Huo², Huihui Lv², Zhensen Chen¹, Yan Han², and He Wang^1,3
1Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China, ²Department of Neurology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai, China, ³Human Phenome Institute, Fudan University, Shanghai, China

The current report summarizes the morphological characteristics of middle cerebral artery quantified from MRA scans in a large sample of older Chinese population and shows that higher M1 radius is an independent predictor of white matter hyperintensities (WMH). Furthermore, as the pathological changes resulting in white matter lesions are heterogeneous, the current study suggest that the spatial distribution patterns of WMH could reflect the underpinning pathological mechanisms, though further studies are required.

Zuozhen Cao¹, Xiaoxia Shen², Fusheng Gao³, Tingting Liu¹, Zhiyong Zhao¹, Hongxi Zhang³, Lizhong Du², Jiangyang Zhang⁴, Yi Zhang¹, Can Lai³, Xiaolu Ma², and Dan Wu^1
1College of Biomedical Engineering & Instrument Science, Zhejiang University, HangZhou, China, ²Department of Neonatal Intensive Care Unit, Children's Hospital affiliated to Zhejiang University School of Medicine, HangZhou, China, ³Department of Radiology, Children's Hospital affiliated to Zhejiang University School of Medicine, HangZhou, China, ⁴Department of Radiology, New York University School of Medicine, New York, NY, United States

Diffusion MRI (dMRI) is known to be sensitive to hypoxic-ischemic encephalopathy (HIE) , however, the existing dMRI studies only used diffusion tensor metrics in a few selected brain regions and primarily focus on severe-to-moderate HIE. Here we investigated microstructural alterations using multi-shell dMRI across the whole-brain in severe, moderate, and mild HIE babies (n=5/13/13) in comparison with control neonates (n=11) with region-of-interest-based, tract-based, and fixel-based analysis. We found microstructural alternations in projection and association fibers, especially the inferior fronto-occipital fasciculus and inferior longitudinal fasciculus that are important for visual functions.

Onila Rasanjala¹, Nguyen Trong Nguyen ², Joohyun Kim³, Eunju Kim³, Ulrich Katscher⁴, Byung Hyun Baek⁵, and Ilwoo Park^1,5
1Department of Artificial Intelligence Convergence, Chonnam National University, Gwangju, Korea, Republic of, ²Department of Biomedical Science, Chonnam National University, Gwangju, Korea, Republic of, ³Philips Korea, Seoul, Korea, Republic of, ⁴Philips Research Laboratories, Hamburg, Germany, ⁵Department of Radiology, Chonnam National University, Gwangju, Korea, Republic of

We demonstrate the feasibility of obtaining conductivity using EPT from patients with stroke. The ischemic lesion exhibited significantly higher conductivity values than the contralateral brain tissue in the cerebral brain, while the pons and cerebellum showed similar levels of conductivity values between the ischemic lesion and the contralateral brain tissue. The levels of conductivity value appeared to be specific to regions. The infratentorial normal brain exhibited a significantly higher level of conductivity than the supratentorial brain. In addition, the levels of conductivity were significantly different between the ischemic lesions of basal ganglia & thalamus and cerebral hemisphere.

Yao Zhang¹, Ruiting Zhang¹, Minming Zhang¹, Yong Zhang², and Peiyu Huang^1
1The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China, ²GE Healthcare, Shanghai, China

The association between the glymphatic dysfunction and cerebral small vessel disease (SVD) is still unclear due a lack of in vivo measures. In this work, we employed a novel method based on the coupling between global blood-oxygen-level-dependent (gBOLD) signal and cerebrospinal fluid (CSF) inflow, which could detect alterations in CSF dynamics. We found that patients with severe SVD had significantly impaired glymphatic function. The dilation of peri-vascular space and the presence of diabetes were associated with worse glymphatic function. These results may provide useful knowledge for understanding the mechanism of SVD and improving clinical treatment.

Jiaqi Dou¹, Song Tian², Yuze Li¹, Ziming Xu¹, Shuo Chen¹, Yajie Wang¹, and Huijun Chen^1
1Center for Biomedical Imaging Research, Tsinghua University, Beijing, China, ²MSC Clinical & Technical Solutions, Philips Healthcare, Beijing, China

Carotid vessel wall segmentation on 3D black-blood MRI is a key step in plaque burden assessment and atherosclerotic lesions identification. In this study, a two-stage weakly-supervised carotid vessel wall segmentation approach was developed using limited manual delineations  on 3D black-blood MR images. First, a global-local context aggregation strategy was used to identify bilateral carotid arteries robustly. Then, distances from artery center to boundaries were regressed in a polar coordinate by PolarMask to segment the vessel wall. The proposed segmentation approach outperformed Attention UNet (Quantitative score: 0.795±0.170 vs. 0.729±0.208) and showed great potential in quantitative atherosclerosis analysis.