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: 8422950
• 负责人: Danny JJ WANG
• 金额: $ 43.05万
• 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 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8422950
• 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; imaging modality; improved; neuroimaging; 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. PUBLIC HEALTH RELEVANCE: Stroke is the fourth leading cause of death in the US with more than 137,000 people dying each year from stroke. This project will develop, refine and validate a noninvasive and quantitative MRI method to measure cerebral blood flow in acute stroke patients, and is expected to improve the management and treatment of stroke patients.

描述（由申请人提供）：灌注成像在急性缺血性卒中（AIS）管理中的作用是确定局部脑血流量（CBF）减少的程度和范围，并有助于识别缺血半暗带-可通过溶栓和/或血管内再通治疗挽救的灌注不足区域。动态磁敏感对比增强（DSC）技术已成为AIS的主要MR灌注成像方法。最初的DEFUSE队列研究表明，灌注扩散不匹配可能预测溶栓治疗的临床反应。然而，随机试验（如EPITHET、DIAS）得出的结果不明确，仅显示当使用灌注和弥散不匹配作为溶栓的患者选择标准时有获益趋势。到目前为止，在AIS的管理中识别缺血半暗带的价值仍然不太确定。动脉自旋标记（ASL）灌注MRI是一种新兴的非增强MRI方法来测量CBF。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，用于描绘低灌注脑区域。ASL还证明了通过延迟动脉传输效应以及使用血管选择性ASL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的动力学并与临床结果相关联。本提案的主要目的是进一步开发、完善和评价ASL用于AIS灌注成像的临床效用。在目标1中，我们将通过纳入动脉通过时间（ATT）测量来改进ASL灌注定量，并对ASL和DSC灌注MRI进行系统评价。在目标2中，我们将通过与数字减影血管造影的金标准进行比较，评价多延迟ASL和血管编码pCASL在确定AIS侧支灌注状态方面的效用。在目标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测量等临床结局相关，评价系列ASL灌注成像的临床实用性。我们假设ASL过度灌注与再灌注、BBB渗漏相关，并且是AIS患者HT的预测因子。目前的项目利用了加州大学洛杉矶分校非常丰富的AIS神经成像和治疗临床资源。这是一个转化项目，目标是开发和验证一种完全无创的定量MRI方法，用于AIS以及其他脑血管疾病的常规临床评价。 公共卫生相关性：中风是美国第四大死亡原因，每年有超过137，000人死于中风。该项目将开发、完善和验证一种无创和定量MRI方法，用于测量急性卒中患者的脑血流量，并有望改善卒中患者的管理和治疗。