Daichi Murayama¹, Takayuki sakai¹, Masami Yoneyama², and Shigehiro Ochi^3
1Radiology, Eastern Chiba Medical Center, Chiba, Japan, ²Philips Japan, Tokyo, Japan, ³Eastern Chiba Medical Center, Chiba, Japan

We combined 3D radial sequences using stack-of-stars acquisition with uTE sampling to enable short-time imaging of local areas. This study was to apply uTE sequences using 3D radial stack-of-stars collection to MRA to determine its usefulness as a follow-up MRA after treatment of cerebral aneurysms metallic devices. The range of signal reduction around the treated area was significantly smaller in the uTE-MRA than in the TOF-MRA. uTE-MRA improved the visualization of peri-aneurysm vessels and neck remnant in the metallic devices. uTE-MRA using 3D radial stack-of-stars collection is useful for follow-up MRA after treatment of cerebral aneurysms metallic devices.

Josh Liu¹, Zhensen Chen¹, Niranjan Balu¹, and Chun Yuan^1
1Electrical and Computer Engineering, University of Washington, Seattle, WA, United States

Blood flow directions in vessels of the Circle of Willis (CoW) may have important implications for stroke risk. In this study, an algorithm is developed to identify the blood flow direction within vessel segments of the Circle of Willis (CoW) using the dynamic MRA component of the recently developed sequence iSNAP. The CoW of twenty-two patients were analyzed using the algorithm, and an ~85% accuracy was achieved with 3D Phase Contrast as the reference. 

Peiyao Chen¹, Chao Jin¹, Xianjun Li¹, Miaomiao Wang¹, Congcong Liu¹, Xiaoyu Wang¹, Fan Wu¹, Yuli Zhang¹, Cong Tian¹, Mengxuan Li¹, Xiaocheng Wei², and Jian Yang^1
1First Affiliated Hospital of Xi 'an Jiaotong University, Xi'an, Shaanxi, China, ²MR Research China, GE Healthcare, Beijing, China

Preterm children often accompany undesirable neurodevelopmental outcomes. Adequate cerebral blood flow (CBF) is essential to brain development and function. However, little is known about relationship among preterm birth, CBF and neurodevelopmental outcome. This study aims to investigate the effect of preterm birth on CBF and explore the relationship between CBF and neurodevelopmental score. Our results suggest that the effects of preterm birth on intellectual development are long lasting and extend even into late childhood. After controlling for age, CBF shows positive correlations with mental and psychomotor development indexes in left frontal and occipital lobes in preterm children.

Xiaoxu Yang¹, Qi Yang², Jiangang Duan², Zhaoyang Fan³, Fang Wu⁴, and Xunming Ji^4
1Chaoyang Hospital, Beijing, China, ²Chaoyang Hospitao, Beijing, China, ³Cedars Sinai Medical Center, Los Angeles, CA, United States, ⁴Xuanwu Hospital, Beijing, China

We evaluated diagnostic and staging performance of BTI in patients with suspected CVST compared with conventional imaging methods in a real-world study. Our results verified high diagnostic value of BTI in a large patient cohort and BTI provided another advantage of accurate staging (acute, subacute and chronic), achieving more thrombosed segments of definite stage, which is important for clinical strategy.

Courtney Whalen¹, Sean Gullette², A. Catharine Ross¹, Rita Castro^1,3, and Thomas Neuberger^4,5
1Nutritional Sciences, The Pennsylvania State University, University Park, PA, United States, ²Huck Institute of the Life Science, The Pennsylvania State University, University Park, PA, United States, ³University of Lisbon, Lisbon, Portugal, ⁴Huck Institute of the Life Science, University Park, PA, United States, ⁵Biomedical Engineering, The Pennsylvania State University, University Park, PA, United States

A ketogenic, low carbohydrate and extremely high fat, diet has been shown to positively impact CVD risk factors. Nevertheless, its effect on atherosclerosis has not been measured. Here, we used 14T MR microscopy to assess atherosclerotic plaque volume, localization, and regional plaque burden in apoE-KO mice fed a ketogenic diet compared to those fed a high fat diet or a control diet. Results show that a ketogenic diet had a protective effect against atherosclerosis compared to a high fat diet as measured by total plaque volume and plaque burden, this effect was not specific to individual regions of the aorta.

Zhe Sun^1,2, Dengrong Jiang³, Marco Muccio¹, Chenyang Li^1,2, Zixuan Lin³, Peiying Liu³, Hanzhang Lu³, and Yulin Ge^1
1Radiology, NYU Langone Health, New York, NY, United States, ²Vilcek Institute of Graduate Biomedical Science, New York University School of Medicine, New York, NY, United States, ³Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States

Vascular dysfunction is frequently found in neurodegenerative and cerebrovascular diseases and closely related to age. Bilateral internal carotid arteries (ICAs) and vertebral arteries (VAs) are the key feeding vessels of the brain, which may provide important indices of intracranial health status. We aimed to evaluate age-related morphological and hemodynamic changes of the vessels using TOF MRA and phase contrast MRI. More tortuous appearance as well as reduced hemodynamics were observed with aging; Blood velocity was found to be associated with the morphology after adjusting age and gender, indicating that high blood velocity and wall shear stress could induce arterial tortuosity.

Kaiyu Zhang¹, Zhensen Chen^1,2, Rui Li², Huijun Chen², Niranjan Balu¹, and Chun Yuan^1,2
1Vascular Imaging Lab and BioMolecular Imaging Center, Department of Radiology, University of Washington, Seattle, WA, United States, ²Center for Biomedical Imaging Research, Tsinghua University, Beijing, China

Multi-contrast images including hemodynamic information in one sequence have significant impact in evaluating intracranial vessels. In this work, we proposed to use FOCI inversion pulse combined with the multi-contrast sequence iSNAP to further improve image quality of dynamic and static MRA. Promising results were obtained from both phantom and in vivo data.

Tongtong Sun¹, Yu Zhang¹, Tongtong Li¹, Yuan Luo², Jinxia Zhu³, Cheng Cheng⁴, and Hongyan Ni^5
1Radiology, First Central Clinical College, Tianjin Medical University, Tianjin, China, ²Radiology, China-Japan Friendship Hospital, Beijing, China, ³MR Collaboration, Siemens Healthcare, Beijing, China, ⁴MR Application, Siemens Healthcare, Beijing, China, ⁵Radiology, Tianjin First Central Hospital, Tianjin, China

This study compared the differences between PETRA-MRA and TOF-MRA on the imaging of the cavernous segment of the ICA with qualitative analysis (image quality) and quantitative analysis (SNR, CNR, CR, and uniformity). The results showed that PETRA-MRA significantly improved the uniformity and CR of the cavernous segment of ICA, although it is inferior in both SNR and CNR. This suggests that PETRA-MRA could provide a reasonable alternative to reduce the loss of signal from curved vessels.

Cheng Zhong¹, Niranjan Balu², Chun Yuan², and Zhensen Chen^2,3
1Fudan University, Shanghai, China, ²Department of Radiology, University of Washington, Seattle, WA, United States, ³Center for Biomedical Imaging Research, School of Medicine, Tsinghua University, Beijing, China

A novel method that exploits spatial-temporal correlation between pixels was developed to segment the dynamic MRA (dMRA) of intracranial arteries. Preliminary results on 3 healthy volunteers demonstrate that the proposed method can effectively identify distal vessels with low signal intensity.

Matthijs de Buck ¹, Peter Jezzard¹, and Aaron Hess^2
1Wellcome Centre for Integrative Neuroimaging, FMRIB Division, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom, ²Oxford Centre for Clinical Magnetic Resonance Research, Department of Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom

3D TOF-MRA at 7T can be greatly accelerated using compressed sensing reconstruction of undersampled acquisitions, but the achieved reconstruction quality depends on the undersampling pattern. In this work, optimal parameters for variable-density Poisson disk undersampling were established. For all acceleration factors, optimal reconstructions were achieved by using small fully-sampled calibration areas of 12x12 lines and a polynomial order of around 2. The optimal undersampling parameters were the same for all acceleration factors, but the importance of using optimized undersampling parameters was found to increase for higher acceleration factors.

Chao Zhang¹, Xinyi Wang¹, and Weiqiang Dou^2
1The First Affiliated Hospital of Shandong First Medical University, Jinan, China, ²GE Healthcare, MR Research China, Beijing, China

This study aimed to quantitatively evaluate thrombus length and its relationship with the severity and prognosis of acute cerebral infarction using high resolution CUBE imaging. National institute of health stroke scale (NIHSS)  score and modified rankin scale (mRS) score were used to quantify the degree of neurological impairment and the prognosis of patients. The length of cerebral artery thrombosis was measured with CUBE imaging. Strong relationship was revealed between the thrombus length and NIHSS or mRS score. We therefore demonstrated that thrombus length measurement based on CUBE MRI can effectively evaluate the severity and prognosis of acute cerebral infarction.  

Xiaoyuan Fan¹, Zhichao Lai¹, Tianye Lin¹, Juan Wei², and Feng Feng^1
1Peking Union Medical College Hospital, Beijing, China, ²GE Healthcare, Beijing, China

Whether preoperative cerebral small vessel disease and carotid near-occlusion are associated with cerebral hyperperfusion (CH) after carotid endarterectomy has not been reported. This study demonstrated that preoperative Fazekas score ≥ 3, number of lacunes ≥ 2 combined with the presence of carotid near-occlusion can accurately predict CH after carotid endarterectomy. This encourages preoperative MRI scans and suggests we should pay particular attention to patients with CSVD and carotid near-occlusion.

Song'an Shang¹, Weiqiang Dou², and Jingtao Wu^3
1Nanjing First Hospital, Nanjing Medical University, Nanjing, China, ²GE Healthcare, MR Research China, Beijing, China, ³Northern Jiangsu People’s Hospital, Yangzhou, China

Flow related artifacts in continuous arterial spin labeling (cASL) zero-echo-time (ZTE) magnetic resonance angiography (MRA) could influence the visualization of vasculature. This study aimed to investigate the clinical feasibility of ZTE-MRA with hybrid arterial-spin-labeling (hASL) tagged for assessing the intracranial artery diseases assessment. Our clinical results indicated that relative to conventional ZTE-MRA, hASL-ZTE-MRA was more robust and superior in the depiction of intracranial artery diseases and follow-up assessment in a clinical population while maintaining a ZTE-derived nature.

Maoxue Wang¹, Yi Wang¹, Yongbo Yang¹, Yongbo Yang¹, Ming Li¹, Jilei Zhang¹, and Bing Zhang^1,2
1The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China, ²Institute of Brain Science, Nanjing University Nanjing, Nanjing, China

A comparison of 4D MRA and 3D TOF MRA in patients with moyamoya vasculopathy after revascularization.

Haruyuki Fukuchi^1,2,3, Toshiya Akatsu⁴, Kei Fukuzawa³, Nao Takano⁴, Yutaka Ikenouchi², Michimasa Suzuki², Kohji Kamagata², Akihiko Wada², Osamu Abe¹, and Shigeki Aoki^2
1Radiology, Department of Radiology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan, ²Department of Radiology, Juntendo University Graduate School of Medicine, Tokyo, Japan, ³Department of Radiology, Toranomon Hospital, Tokyo, Japan, ⁴Department of Radiology, Juntendo University Hospital, Tokyo, Japan

We developed and refined a novel method, Variable TI, to improve the visibility of ASL based UTE 4D-MRA. From numerical simulations and the flow phantom studies we found the signal tendency and blood signal skipping phenomena. With refined parameters we got 50% of signal enhancement comparing to conventional method. We conduct volunteer study with the refined Variable TI UTE 4D-MRA and this novel method offered a higher signal intensity and improved visualization of arteries in late phase compared to the conventional method. The Variable TI technique can improve clinical usability of 4D-MRA.

Tzu-Cheng Chao¹, Guruprasad Krishnamoorthy², and James G. Pipe^1
1Department of Radiology, Mayo Clinic, Rochester, MN, United States, ²Philips Healthcare, Gainesville, FL, United States

2D TOF MRA provides important diagnostic information around carotid bifurcation. However, the image is prone to artifacts caused by pulsatile flow. The present work utilized Temporal Harmonic Encoding scheme to reduce these artifacts by extracting only the static signals for MRA. Meanwhile, the harmonic components containing dynamic information could also be used as a reference. 

Sihan Chen¹, Changsheng Liu¹, Xixiang Chen¹, Ling Ma², and Yunfei Zha^1
1Radiology, Renmin Hospital of Wuhan University and Hubei General Hospital, Wuhan, China, ²Advanced Application Team, GE Healthcare, Wuhan, China

This study aimed to assess the vulnerability of carotid atherosclerotic plaques using the combination of radiomics nomogram and clinical high-risk factors. Texture features were extracted from high-resolution multi-contrast magnetic resonance imaging. Radscore was applied to build a diagnostic model with the consideration of hrMRI texture features and patient demography to assess the power in differentiating vulnerable and stable lesions. The radscore showed a better diagnostic performance. The combination model of texture and clinical information had the best performance in assessing lesion vulnerability. This study demonstrated that hrMRI texture features provided incremental value for the carotid atherosclerotic vulnerability assessment.

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

In this study, the main purpose was to explore the feasibility of 3D pseudo-continuous territory arterial spin labeling (tASL) in evaluating unilateral middle cerebral artery (MCA) recanalization. We included 47 patients with unilateral MCA stenosis diagnosed by DSA and performed tASL examination. Increased relative cerebral blood flow (rCBF) values were found in the blood supply area of MCA postoperatively than pre-operatively. Good prognosis was also revealed to closely associate with Alberta Stroke Program Early CT Score (ASPECTS) scores based on tASL perfusion images. Therefore, tASL can be used as one valuable method to diagnose the effect of vascular recanalization.

Mariya Stanislavovna Pravdivtseva¹, Prasanth Velvaluri², Fritz Wodarg¹, Eckhard Quandt², Rodrigo Lima de Miranda³, Jan-Bernd Hövener¹, Philipp Berg⁴, and Olav Jansen^1
1Department of Radiology and Neuroradiology, Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), University Medical Center Schleswig-Holstein (UKSH), Kiel University, Kiel, Germany, Kiel, Germany, ²Chair for Inorganic functional materials, University of Kiel, Kiel, Germany, Kiel, Germany, ³Acquandas GmbH, Kasierstrasse 2, Kiel, Germany, Kiel, Germany, ⁴Research Campus STIMULATE, University of Magdeburg, Magdeburg, Germany, Magderburg, Germany

Intracranial aneurysms are a life-threatening disease, which can be treated with flow diverter stents. However, complications during or after this endovascular treatment might occur. Therefore, there is a need to improve the current minimally-invasive technologies. In the present study, we proposed and utilized the concept of the iterative stent design focusing on 1) fast prototyping using microsystem  technologies and 2) in vitro testing the flow reduction in real-world conditions using 4D flow MRI. As a result, the flow volume entering the aneurysm in the presence of a stent was reduced by 10 %, and then by 85 %.

Yue Qin¹, Xin Li¹, Yinhu Zhu¹, Dayong Jin¹, Yifan Qian¹, Juan Tian¹, Liyao Liu¹, Yanqiang Qiao¹, and Shaoyu Wang^2
1XIAN DAXING HOSPITAL, Xi'an, China, ²MR Scientific Marketing, Siemens Healthineers, Xi'an, China

Magnetic resonance angiography (MRA) is increasingly used as a non-invasive method to assess carotid arteries. TOF-MRA, because it is dependent on the flow of magnetized blood into the volume being imaged, is highly susceptible to conditions that disrupt laminar flow. Depiction of the carotid region using Silent imaging was often superior to that obtained with conventional techniques, where the ultrashort TE minimized flow-related signal dropout. This study aimed to evaluate the feasibility of PETRA-MRA in imaging the vascular structures of the extracranial carotid arteries. We found that PETRA-MRA showed significantly higher image quality and better visualized extracranial carotid arteries.