Arterial Spin Labeled Perfusion MRI in Acute Ischemic Stroke

急性缺血性中风的动脉旋转标记灌注 MRI

• 批准号: 8722050
• 负责人: Danny JJ WANG
• 金额: $ 41.99万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8722050
• 关键词: Acute; Blood - brain barrier anatomy; Brain region; Cause of Death; Cerebrovascular Circulation; Cerebrovascular Disorders; Clinical; Clinical Trials; Cohort Studies; Contrast Media; Diffusion; Digital Subtraction Angiography; Evaluation; Extravasation; Functional disorder; Goals; Gold; Heterogeneity; Image; Injection of therapeutic agent; Ischemic Penumbra; Ischemic Stroke; Label; Lesion; Magnetic Resonance Imaging; Maps; Measurement; Measures; Methods; Nature; Outcome; Patient Selection; Patients; Perfusion; Permeability; Predisposition; Process; Reperfusion Therapy; Residual state; Resources; Role; Scheme; Selection Criteria; Spin Labels; Stroke; Techniques; Thrombolytic Therapy; Time; Tissues; Vascular blood supply; acute stroke; base; clinically significant; hemodynamics; hypoperfusion; imaging modality; improved; neuroimaging; public health relevance; randomized trial; research clinical testing; response; thrombolysis; trend

DESCRIPTION (provided by applicant): The role of perfusion imaging in the management of acute ischemic stroke (AIS) is to establish the degree and extent of reduced regional cerebral blood flow (CBF), and to contribute to the identification of the ischemic penumbra - regions of hypoperfusion that may be salvaged by thrombolytic and/or endovascular recanalization therapies. Dynamic susceptibility contrast enhanced (DSC) techniques have been the main MR perfusion imaging method used in AIS. The initial DEFUSE cohort study suggested that perfusion-diffusion mismatch may predict clinical responses to thrombolytic therapy. Randomized trials (e.g. EPITHET, DIAS), however, have yielded ambiguous findings showing only trends to benefit when using perfusion and diffusion mismatch as a patient selection criterion for thrombolysis. To date, the value for identifying the ischemic penumbra in the management of AIS remains less than firmly established. Arterial spin labeled (ASL) perfusion MRI is an emerging non-contrast MRI method to measure CBF. With the latest implementation using pseudo- continuous ASL (pCASL) and background suppressed 3D GRASE, we recently demonstrated that ASL can be reliably applied for acute stroke imaging, and provides consistent results with DSC perfusion MRI for delineating hypoperfused brain regions. ASL also demonstrates the potential to illustrate collateral blood supply through delayed arterial transit effects as well as the use of vessel-selective ASL. Because ASL is easy, fast and does not require the injection of contrast agents, serial perfusion imaging can be performed to trace the dynamics of reperfusion and correlate with clinical outcomes. The main purpose of this proposal is to further develop, refine and evaluate the clinical utility of ASL for perfusion imaging in AIS In Aim 1, we will improve ASL perfusion quantification by including arterial transit time (ATT) measurement and perform a systematic evaluation of ASL and DSC perfusion MRI. In Aim 2, we will evaluate the utility of multi-delay ASL and vessel encoded pCASL in determining the state of collateral perfusion in AIS by comparison with the gold standard of digital subtraction angiography. In Aim 3, we will evaluate the clinical utility of serial ASL perfusion imaging by correlating with clinical outcomes such as reperfusion, hemorrhagic transformation (HT) and DSC measures of blood-brain barrier (BBB) permeability in AIS patients. We hypothesize that ASL hyperperfusion is associated with reperfusion, BBB leakage and is a predictor of HT in AIS patients. The present project capitalizes on the extremely rich clinical resources for AIS neuroimaging and treatments at UCLA. It is a translational project with the goal to develop and validate an entirely noninvasive and quantitative MRI method for routine clinical evaluation of AIS as well as other cerebrovascular disorders.

描述（由申请人提供）：灌注成像在急性缺血性卒中（AIS）治疗中的作用是确定区域脑血流量（CBF）减少的程度和范围，并有助于识别缺血半暗带-低灌注区域，这些区域可以通过溶栓和/或血管内再通治疗来挽救。动态敏感性对比增强（DSC）技术一直是AIS中主要的MR灌注成像方法。最初的化解队列研究表明，灌注-扩散不匹配可以预测溶栓治疗的临床反应。然而，随机试验（如EPITHET、DIAS）得出了模棱两可的结果，表明当使用灌注和扩散不匹配作为溶栓患者选择标准时，只有趋势是有益的。迄今为止，鉴别缺血性半暗带在AIS治疗中的价值还没有得到明确的确立。动脉自旋标记（ASL）灌注MRI是一种新兴的测量脑血流的非对比MRI方法。通过使用伪连续ASL （pCASL）和背景抑制3D GRASE的最新实现，我们最近证明ASL可以可靠地应用于急性卒中成像，并提供与DSC灌注MRI一致的结果来描绘低灌注脑区。ASL还显示了通过延迟动脉运输效应以及血管选择性ASL的使用来说明侧支血供的潜力。由于ASL简单、快速且不需要注射造影剂，因此可以进行连续灌注成像以追踪再灌注动态并与临床结果相关联。本提案的主要目的是进一步发展，完善和评估ASL在AIS灌注成像中的临床应用。在Aim 1中，我们将通过包括动脉传递时间（ATT）测量来改进ASL灌注量化，并对ASL和DSC灌注MRI进行系统评估。在Aim 2中，我们将通过与数字减影血管造影的金标准进行比较，评估多延迟ASL和血管编码pCASL在确定AIS侧支灌注状态方面的效用。在Aim 3中，我们将通过与AIS患者的再灌注、出血性转化（HT）和血脑屏障（BBB）通透性的DSC测量等临床结果的相关性来评估连续ASL灌注成像的临床应用。我们假设ASL高灌注与再灌注、血脑屏障渗漏相关，是AIS患者HT的预测因子。本项目利用加州大学洛杉矶分校极其丰富的AIS神经成像和治疗临床资源。这是一个转化项目，目的是开发和验证一种完全无创的定量MRI方法，用于AIS和其他脑血管疾病的常规临床评估。