Huiru Pan^1,2, Yingying Li³, Huilou Liang^1,2, Tingyan Yao⁴, Xingfeng Shao⁵, Xuejia Jia³, Zihao Zhang^1,2,6, Zhentao Zuo^1,2,6, Jing An⁷, Danny JJ Wang⁵, Rong Xue^1,2,8, and Qi Yang^3
1Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, ²University of Chinese Academy of Sciences, Beijing, China, ³Department of Radiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China, ⁴Department of Neurology, Xuanwu Hospital of Capital Medical University, National Clinical Research Center for Geriatric Diseases, Beijing, China, ⁵Mark & Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States, ⁶The Innovation Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Beijing, China, ⁷Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, China, ⁸Beijing Institute for Brain Disorders, Beijing, China

We applied 3D diffusion-prepared pseudo-continuous arterial spin labeling (DP-pCASL) to evaluate water exchange rate (k_w) of blood brain barrier (BBB) and its association with clinical characteristics of cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) patients. The CARASIL group showed significantly decreased k_w and cerebral blood flow (CBF) compared with healthy controls. The association between k_w with age, CBF and white matter hyperintensity volumes (WMH) found in CARASIL patients suggest that k_w could be a potential non-contrast imaging biomarker for BBB dysfunction in cerebral small vessel disease.

Dinil Sasi S¹, Rakesh Kumar Gupta², Rana Patir², Suneeta Ahlawat², and Anup Singh^1,3
1Center for Biomedical Engineering, Indian Institute of Technology Delhi, New Delhi, India, ²Fortis Memorial Research Institute, Gurugram, India, ³All India Institute of Medical Sciences New Delhi, New Delhi, India

Dynamic-contrast-enhanced (DCE)-MRI has shown wide potential in characterizing brain tumor. Conventionally, generalized-tracer-kinetic-model (GTKM) and Patlak-model (PM) have been widely used in clinics to characterize the blood-brain-barrier (BBB) integrity of the tumor. However, PM is recommended for DCE-MRI data with shorter duration (less than 1 minute) and GTKM may overfit in non-enhancing and normal tissues causing erroneous estimation of extra-vascular volume fraction (v_e). So, the current study proposes a hybrid tissue depended model with maximum 2 model fitting parameters by combining GTKM and PM depending on underlying tissue. Proposed model has outperformed GTKM in all tissue regions.

Osamu Togao¹, Makoto Obara², Kazufumi Kikuchi³, Tatsuhiro Wada⁴, Chiaki Tokunaga⁴, Ryoji Mikayama⁴, Shingo Baba³, Marc Van Cauteren⁵, Akio Hiwatashi³, and Kousei Ishigami^3
1Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, ²Philips Japan, Tokyo, Japan, ³Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, ⁴Division of Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, ⁵Philips Healthcare, Tokyo, Japan

The aim of the present study was to determine whether the dynamic pCASL using a variable-TR scheme with optimized background suppression is useful for assessing cerebral perfusion in patients with Moyamoya disease by comparing with ¹²³I-IMP SPECT. ASL dynamic data at 10 time points are acquired by changing the label duration and post label delay. Significant correlations were found between SPECT-CBF and ASL-CBF and between arterial transit time (ATT) and cerebrovascular reactivity (CVR) to acetazolamide challenge on SPECT. ATT was significantly longer in areas where the CVR was decreased than in areas where the CVR was maintained.

Huilou Liang^1,2, Lianwang Li^3,4, Shengyu Fang^3,4, Yinyan Wang^3,4, Yuchao Liang^3,4, Zeshan Yao⁵, Jing An⁶, Yan Zhuo^1,2,7, Lei Wang^3,4, Lijuan Zhang⁸, Danny JJ Wang⁹, and Rong Xue^1,2,10
1State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China, ²University of Chinese Academy of Sciences, Beijing, China, ³Beijing Neurosurgical Institute, Beijing, China, ⁴Department of Neurosurgery, Beijing Tiantan Hospital, Beijing, China, ⁵AnImage Tech. Beijing Co., Ltd., Beijing, China, ⁶Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen, China, ⁷CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Beijing, China, ⁸Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China, ⁹Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States, ¹⁰Beijing Institute for Brain Disorders, Beijing, China

The clinical treatment and prognosis of oligodendrogliomas are closely related to the histopathological grade. As a non-invasive and non-contrast perfusion imaging technique, arterial spin labeling (ASL) has been widely used in studies of glioma grading. The estimation of cerebral blood flow (CBF) in conventional single-delay ASL can be affected by the arterial transit time (ATT) effect. Here, multi-delay 3D ASL providing multiple hemodynamic parameters including ATT and ATT-corrected CBF was used to analyze the histogram-based perfusion features in oligodendrogliomas. Our results showed no difference in rCBF between WHO grade 2 and 3 oligodendrogliomas, but prolonged rATT in higher grade oligodendrogliomas.

Lixian Zou^1,2, Jialing Chen³, Yuan Zheng⁴, Yu Ding⁴, Yubao Liu³, Jian Xu⁴, Hairong Zheng^1,2, and Xin Liu^1,2
1Paul C. Lauterbur Research Centre for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Science, Shenzhen, China, ²Shenzhen College of Advanced Technology, University of Chinese Academy of Sciences, Shenzhen, China, ³Medical Imaging Center, Shenzhen Hospital, Southern Medical University, Shenzhen, China, ⁴UIH America Inc., Houston, TX, United States

A whole heart perfusion imaging with auto-calibrated multiband CAIPIRINHA with through-time encoding and iterative reconstruction (tMB+CS-FPP) has been proposed to acquire multiple slices simultaneously without extra reference scans. The technique can achieve perfusion images with doubled anatomic coverage with identical spatial resolution. In this study, we compared the performance of the tMB+CS-FPP using different k-t undersampling patterns in a phantom study. And the proposed method was performed to the patients with suspect CAD and was compared to the conventional FPP. 

Yan Tong¹, Qing Wei², and Jun Xie^2
1Shenzhen United Imaging Research Institute of Innovative Medical Equipment Innovation Research, Shenzhen, China, ²United Imaging Healthcare, Shanghai, China

Arterial spin labeling (ASL) benefits from both increased intrinsic SNR and reduced T₁ relaxation time at higher field strength. However, the implementation of ASL at 7T is challenging, primarily due to increased SAR, and B₁⁺/B₀ inhomogeneity. Recently, United Imaging Healthcare introduced a 5T whole-body scanner. 5T might be a superior field strength for ASL due to the improved SNR compared to 3T, and less severe B₁⁺/B₀ inhomogeneity and reduced SAR compared to 7T. This study demonstrated the feasibility of high-resolution ASL at 5T, and the results showed superior SNR compared to 3T.

Peifang Miao¹, Caihong Wang¹, Ying Wei¹, Jingliang Cheng¹, and Kaiyu Wang^2
1The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China, ²GE Healthcare MR Research, Beijing, China, Beijing, China

To quantify cerebral blood flow (CBF) dynamic evolution and the relationship with clinical outcomes during recovery in right subcortical stroke patients,ASL and neurological examinations were performed repeatedly in 25 patients at 4 time points and 26 healthy controls (HCs) once.One-way Within-Subjects ANOVA and two sample test,pearson correlation analyses were performed.Compared with HCs, patients displayed continuous crossed cerebellar diaschisis.Increased CBF of contralesional sensorimotor cortex in the subacute and chronic are vital for recovery.Patients showed dynamic changes of CBF in contralesional cerebellum superior and occipital lobe,which were negatively correlated with memory.Findings provide a theoretical basis for functional impairment and recovery after stroke.

Shota Ishida¹, Hirohiko Kimura², Naoyuki Takei³, Yasuhiro Fujiwara⁴, Tsuyoshi Matsuda⁵, and Nobuyuki Kosaka^2
1Department of Radiological Technology, Faculty of medical sciences, Kyoto College of Medical Science, Nantan, Japan, ²Department of Radiology, Faculty of Medical Sciences, University of Fukui, Eiheiji, Japan, ³GE Healthcare, Tokyo, Japan, ⁴Department of Medical Image Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan, ⁵Division of Ultra-high Field MRI, Institute for Biomedical Science, Iwate Medical University, Shiwa-gun, Japan

This study aimed to assess whether the efficiency of DANTE, a vascular suppression in ASL, is affected by vascular territories. CBF, transit times (TT), and their rates of change were determined in nine vascular territories from the proximal to distal regions. Although CBF reduction rates were not different among the territories, TT extension rates were lower in the distal region than in other regions. No correlation was observed between TT extension and CBF reduction rates. DANTE efficiency is not affected by transit time or vascular territories. Homogenous vascular suppression effects could be obtained by DANTE-ASL.

Jichang Zhang¹, Xinpei Wang¹, Faisal Najeeb², Pengfei Xu¹, Hammad Omer², Penny Gowland³, Sue Francis³, Paul Glover³, Richard Bowtell³, and Chengbo Wang^1
1SPMIC, The University of Nottingham Ningbo China, Ningbo, China, ²COMSATS University Islamabad, Islamabad, Pakistan, ³SPMIC, The University of Nottingham, Nottingham, United Kingdom

This work presents a motion corrected free breathing Dynamic Contrast Enhanced MRI (DCE-MRI) with improved dynamic contrast reconstruction method called L+S with soft weighting and joint sparsity. Soft weighting achieves accurate motion correction at expense of dynamic contrast. An additional temporal Fast Fourier Transform (FFT) constraint is used to recover the dynamic contrast. A simulated phantom dataset was created with ground truth in this work, enabling quantification of the motion correction and dynamic contrast performance. The proposed method achieved improved dynamic contrast, better motion correction and high reconstruction efficiency simultaneously.

Shilan Li¹, Jiahuan Tao¹, Jing Zhang¹, and Kai Ai^2
1Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, China, ²Philips Healthcare, Xi’an, China

 To explore the possibility of application of free breathing intravoxel incoherent motion (IVIM) imaging in pediatric myocarditis patients, we utilized diaphragmatic navigation technique to detect heart rate and improved the probability of scanning success. Eight pediatric myocarditis patients and ten healthy volunteers were enrolled. The study confirmed that the IVIM imaging method with free breathing condition was acceptable and achievable. Besides, compared with healthy children, the microcirculation of myocarditis patients was impaired, and pseudo-diffusion coefficient (Dfast) and perfusion fraction (f) were significantly lower. 

Makoto Obara¹, Osamu Togao², Lena Vaclavu³, Tatsuhiro Wada⁴, Chiaki Tokunaga⁴, Ryoji Mikayama⁴, Hiroshi Hamano¹, Matthias van Osch³, Kim van de Ven⁵, and Marc Van Cauteren^6
1Philips Japan, Tokyo, Japan, ²Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences,, Kyushu University, Fukuoka, Japan, ³C.J. Gorter center for high field MRI, department of Radiology,, Leiden University Medical Center, Leiden, Netherlands, ⁴Division of Radiology, Department of Medical Technology,, Kyushu University Hospital, Fukuoka, Japan, ⁵Philips Healthcare, Best, Netherlands, ⁶Philips Healthcare, Tokyo, Japan

There are two approaches proposed to calculate cerebral blood flow (CBF) and arterial transit time (ATT) accurately, while ensuring sufficient SNR. One is time-encoded (TE) and the other is sequential variable-TR (vTR) pseudo-continuous arterial spin labeling (PCASL). In this study, we measured SNR, CBF, and ATT from these two methods and compared and verified their validity in 5 healthy subjects. The higher SNR was secured in TE-PCASL compared to vTR-PCASL. On the other hand, ATT calculated from vTR-PCASL showed higher correlation coefficient with reference compared with TE-PCASL. The CBF calculated from both schemes showed high correlation coefficient with reference.