Jinhao Lyu¹ and Xin Lou^1
1Chinese PLA General Hospital, Beijing, China

Penumbral tissue identification is critical for the treatment decision for patients with acute ischemic stroke. In the present study, we aimed to assess the impact of arterial spin labeling (ASL) at different post-labeling delays (PLDs) in penumbral tissue quantification, and compare their performances in patients’ selection for endovascular treatment with dynamic susceptibility contrast as reference. The results showed ASL appears to persistently overestimate penumbral tissue in acute ischemic stroke. PLD shows substantial impact on quantification of hypoperfusion volume. Long PLD, 2500ms for example, is preferable in penumbral tissue detection and patients’ selection.

Yuelei Lyu¹, Hua Gu¹, Yanping Xue¹, Lizhi Xie², Tao Jiang¹, and Qi Yang^1
1Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China, ²MR Research China, GE Healthcare, Beijing, China

This study investigated the feasibility of 3D PCASL to detect crossed cerebellar diaschisis (CCD) in patients with unilateral supratentorial subacute stroke using two PLD method and correlated the ischemic perfusion with CCD to identify the relevant imaging factors of CCD development. 3D PCASL can detect CCD in patients of supratentorial subacute stroke. Patients of supratentorial subacute stroke experience late-arriving flow while CCD+ patients suffer late arriving flow in the affected contralateral cerebellum. CCD+ patients may have a propensity towards more hemodynamic compromise and compensatory collateral flow in the cerebellum.

Sangni Liu¹, Dandan Fan¹, and Chunming Xie^1
1Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China

Robust collateral circulation is strongly associated with better outcomes in acute ischemic stroke. In this prospective study, collateral circulation was defined as arterial transit artifact in Arterial Spin Labeling(ASL) images. Patients with ASL collaterals represented higher rate of good outcome and there were significant differences for percent changes of mRS score and NIHSS score between groups. Furthermore, the presence of ASL collaterals could predict good outcome, even after controlling for baseline NIHSS score. Taken together, ASL collaterals provide a powerful tool to predict clinical outcome for acute ischemic stroke with 90 days follow-up.

Xiaoyuan Fan¹, Tianye Lin¹, Juan Wei², Jianxun Qu², Zhentao Zuo¹, and Feng Feng^1
1Peking Union Medical College Hospital, Beijing, China, ²GE healthcare, Beijing, China

Preoperative measurement of cerebrovascular reactivity using acetazolamide or CO2 induced SPECT is the gold standard for predicting cerebral hyperperfusion (CH) after carotid endarterectomy (CEA). However, it is often impractical to perform SPECT examinations on all patients.

Arterial spin labeling (ASL) is a non-invasive technique to image the brain perfusion. Based on multi-delay ASL perfusion map, we extracted two hemodynamic parameters (cerebral blood flow and arterial transit time) and established a five-scale scoring system for the prediction of CH.

We found in patients with carotid stenosis, multi-delay ASL is a practical and reliable tool for the prediction of CH after CEA.

Marta Calvo-Imirizaldu¹, Verónica Aramendia-Vidaurreta^1,2, Marta Vidorreta³, Reyes García-Eulate^1,2, Pablo Domingez Echeverri^1,2, Josef Pfeuffer⁴, Bartolome Bejarano⁵, Lain Hermes Gonzalez-Quarante⁵, Antonio Martinez-Simon⁶, and María Fernández-Seara^1,2
1Radiology, Clínica Universidad de Navarra, Pamplona, Spain, ²IDISNA, Pamplona, Spain, ³Siemens Healthcare, Madrid, Spain, ⁴Application Development, Siemens Healthcare, Erlangen, Germany, ⁵Neurosurgery, Clínica Universidad de Navarra, Pamplona, Spain, ⁶Anesthesia and Intensive Care, Clínica Universidad de Navarra, Pamplona, Spain

ASL has shown potential to depict residual tumor compared to anatomical imaging in previous intraoperative MRI (iMRI) study performed at 1.5T. However, the technique has not been evaluated at higher field, where field inhomogeneities could compromise the labeling efficiency. We aimed to assess feasibility and utility of iMRI-ASL at 3T. To that end, a PCASL sequence was evaluated in 10 patients. In one patient ASL depicted an additional high CBF focus indicating neovascularization (known to correlate with higher grade component) that wasn’t depicted in the anatomical images, favoring the use of ASL in the iMRI setting to achieve maximal resection.

Andrea Kronfeld¹, Alexandra Russo², Nicole Henninger², Arthur Wingerter², Moritz Brunk², Kaml Khawaja¹, Andrei Tropine¹, Abdulghani Moussa Pacha¹, Violeta Dimova³, Federico Marini^4,5, Doris Leithner⁶, Sabine Nospes⁷, Roman Kloeckner⁸, Felix Hahn⁸, Marcus Stockinger⁹, Heinz Schmidberger⁹, Marc Brockmann¹, Marie Astrid Neu², Joerg Faber², and Yasemin Tanyildizi^1
1Neuroradiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany, ²Pediatric Hematology, Oncology & Hemostaseology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany, ³Neurology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany, ⁴Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany, ⁵Institute of Medical Biostatistics, Epidemiology and Informatics, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany, ⁶Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany, ⁷Otolaryngology, Head and Neck Surgery, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany, ⁸Diagnostic and Interventional Radiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany, ⁹Radiation Oncology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany

28 patients after earlier (1-45 years) whole brain radiation and 22 healthy controls were examined by arterial spin labeling to discover insights ASL could give in long-term effects of radiation therapy in the healthy brain. Relative cerebral blood flow and relative bolus arrival time showed increased values compared to the healthy control, which could be a sign for increased permeability and thickening of the vessels, two well described effects of radiation therapy ASL gives insight into.

zongqiong sun¹ and Weiqiang Dou^2
1Department of radiology, Affiliated hospital of Jiangnan university, Wuxi, China, ²GE healthcare,MR research China, Beijing, China

This study mainly investigated the feasibility of 3D pseudo-continuous arterial spin labeling (3D-pCASL) imaging in predicting the treatment response to chemoradiotherapy (CRT) for advanced nasopharyngeal carcinoma (ANPC) patients. 3D-pCASL derived blood flow (BF)s in tumors were respectively obtained for patients in response group (RG) and no-response group (NRG). The resultant pre-treatment BF showed significantly different values between RG and NRG patients. Combining with clinical information, BF also showed robust prediction between RG and NRG patients. Therefore, 3D-pCASL could be considered an effective method in tumor response prediction to CRT for ANPC patients before clinical treatment.

Huihui Kong¹, Jing An², Jiaxin Cao³, Jinfan Tian⁴, Jingwen Yong⁴, Xiantao Song⁴, and Yi He^3
1Radiology, Beijing Friendship Hospital, Beijing, China, ²Siemens Healthcare, Beijing, China, ³Beijing Friendship Hospital, Beijing, China, ⁴Beijing Anzhen Hospital, Beijing, China

This study investigated the side effects and safety of ATP as a stressor for stress perfusion cardiac magnetic resonance. The result showed the high safety of stress perfusion with ATP and side effects were mild and resolved shortly after receiving ATP. Furthermore, it was also observed splenic switch-off that can be used to assess stress adequacy undergoing stress-CMR with ATP.

Zejun Wang¹, Bao Wang², Ziyi Huang³, Yingchao Liu⁴, and Ruiliang Bai^1,5
1Key Laboratory of Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, China, ²Department of Radiology, Qilu Hospital of Shandong University, Jinan, China, ³College of Life Sciences, Zhejiang University, Hangzhou, China, ⁴Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China, ⁵Department of Physical Medicine and Rehabilitation, Interdisciplinary Institute of Neuroscience and Technology, The Affiliated Sir Run Run Shaw Hospital, School of Medicine,, Zhejiang University, Hangzhou, China

The physiological parameters estimated from pharmacokinetic modeling of DCE-MRI are usually biased by the non-white, spatially-dependent noise. In this study, we compared several state-of-arts denoising approaches, including gaussian low pass filter (GLPF), the dynamic nonlocal mean (DNLM), the nonlocal mean based on spatiotemporal patches (NLM-ST), 2D and 3D kinetics-induced bilateral filter (KIBF). Our results reveal that the 3D KIBF can reduce the noise significantly and reserve subtle information best.

Siddhant Dogra¹, Xiuyuan Wang², Jelle Veraart¹, Alejandro Gupta¹, Koto Ishida³, Deqiang Qiu⁴, and Seena Dehkharghani^1,3
1Department of Radiology, New York University Langone Health, New York, NY, United States, ²Department of Radiology, Weill Cornell Medicine, New York, NY, United States, ³Department of Neurology, New York University Langone Health, New York, NY, United States, ⁴Department of Radiology, Emory University, Atlanta, GA, United States

Acetazolamide-augmented blood-oxygen-level-dependent (ACZ-BOLD MRI) provides robust estimation of cerebrovascular reactivity (CVR). Past approaches are limited to extraction of terminal CVR at arbitrarily selected times in the pharmacologic response, due to low signal-to-noise characteristics. We previously introduced a computational framework that pre-conditions the BOLD response for dynamic analysis and extraction of maximal, rather than terminal augmentation profiles, and novel hemodynamic signatures such as ACZ-BOLD time-to-maxima (T_max). Several consistent and sometimes paradoxical patterns have emerged, the presentation of which we considered timely for this potentially novel hemodynamic neuroimaging biomarker.

Zhangxuan Hu¹, Zhe Zhang^2,3, Yuanren Zhai⁴, Long Qian¹, Binbin Sui^2,3, and Dong Zhang^4
1GE Healthcare, Beijing, China, ²Tiantan Neuroimaging Center of Excellence, Beijing Tiantan Hospital, Capital Medical University, Beijing, China, ³China National Clinical Research Center for Neurological Diseases, Beijing, China, ⁴Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China

It has been shown that the BOLD delay calculated from resting-state fMRI can reveal perfusion information. In this study, the correlation between BOLD delay and CBF measured from ASL were explored. The results showed the inter-subject correlation between BOLD delay and CBF values. Meanwhile, the inter-group differences of the correlation coefficients between Moyamoya patients and healthy controls were also compared.

Fei Chen¹, Zhenyu Dai¹, Lizheng Yao¹, Congsong Dong¹, Haicun Shi², and Weiqiang Dou^3
1Department of Radiology, the Yancheng School of Clinical Medicine of Nanjing Medical University, Yancheng, China, ²Department of Neurology, the Yancheng School of Clinical Medicine of Nanjing Medical University, Yancheng, China, ³GE Healthcare, MR Research China, Beijing, China

This work explored the association of cerebral microvascular perfusion and diffusion dynamics measured by intravoxel incoherent motion (IVIM) imaging with initial neurological function and clinical outcome in acute stroke patients. Significant negative correlations were revealed between IVIM derived diffusion dynamics parameters and initial neurological function as well as clinical outcome for patients with acute ischemic stroke. However, no similar statistical correlation was found for parameters related to microvascular perfusion. IVIM may be therefore suggested as an effective non-invasive method for evaluating the initial neurological function and clinical outcome in acute ischemic stroke.

Yixi Xue¹, Russell W. Chan^1,2, Sarah Y. Wu¹, Emily L. Tse¹, Muneeb A. Faiq¹, Thajunnisa A. Sajitha¹, and Kevin C. Chan^1,3
1Department of Ophthalmology, New York University Grossman School of Medicine, New York, NY, United States, ²Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States, ³Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States

The recent development of relative cerebrovascular reactivity (rCVR) mapping derived from task-free resting-state blood-oxygenation-level-dependent fMRI resolves issues of experimental complications from hypercapnic challenge or pharmacological administrations required in conventional CVR mapping. While human clinical rCVR studies have begun, there lacks rCVR characterization in healthy adult rodents before it can be applied to preclinical models of neuropathology for translational research. This study demonstrated the feasibility of rCVR mapping using resting-state fMRI at 7 Tesla in mice. The results also revealed potential rCVR lateralization in cortical regions and heterogenous vascularization along the septotemporal axis of the hippocampus.  

Botian Xu¹, Chau Vu¹, Matthew Borzage², and John Wood^2
1University of Southern California, Los Angeles, CA, United States, ²Children's Hospital Los Angeles, Los Angeles, CA, United States

Cerebrovascular reactivity (CVR), measuring the ability of vessel dilation or constriction, is an important indicator of cerebrovascular health. As a parameter describing the hemodynamic changes, CVR requires a physiological challenge as the stimulus and monitors the response of the brain metabolism. We propose a frequency-based approach, which applies general linear model (GLM) on the magnitude of the stimulus and response spectrum to avoid challenges with signal alignment and improve robustness to noise in CVR estimation.

Chunqiu Su¹, Xiance Zhao², Jilei Zhang², Xunning Hong¹, and Shanshan Lu^1
1Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China, ²Philips Healthcare, Shanghai, China

Arterial spin labeling (ASL) is a non-invasive MRI perfusion technique that can quantify tissue blood flow, which is meaningful for clinical applications. However, ASL perfusion images always have a limited signal-to-noise ratio (SNR). We aimed to using the echo planar imaging with compressed SENSE (EPICS) to obtain high-quality brain ASL images. Eleven healthy subjects and four patients with intracranial infarction were enrolled, and underwent ASL imaging with and without EPICS. The results demonstrated the feasibility of EPICS to increase the quality of ASL images.