Quantifying Collateral Perfusion in Cerebrovascular Disease

量化脑血管疾病的侧支灌注

• 批准号: 8112019
• 负责人: Gregory George Zaharchuk
• 金额: $ 61.38万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-05 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8112019
• 关键词: Academic Medical Centers; Acetazolamide; Acute; Affect; Alberta province; Angiography; Anterior; Blood Circulation; Blood Vessels; Blood Volume; Blood flow; Bolus Infusion; Brain; Bypass; Caring; Cerebral Angiography; Cerebrovascular Circulation; Cerebrovascular Disorders; Cerebrum; Chronic; Circle of Willis; Clinical; Coagulation Process; Collateral Circulation; Dependence; Diagnostic; Diffusion; Diffusion weighted imaging; Digital Subtraction Angiography; Disease; Early treatment; Echo-Planar Imaging; Evaluation; Fibrosis; Goals; Gold; Growth; Health; Hour; Image; Imagery; Imaging Device; Incidence; Infarction; Internal carotid artery structure; Intervention; Intracranial Hemorrhages; Ischemic Stroke; Knowledge; Label; Lateral; Lead; Link; Magnetic Resonance; Magnetic Resonance Imaging; Mainstreaming; Maps; Measures; Methods; Modality; Modeling; Morphologic artifacts; Moyamoya Disease; Newly Diagnosed; Noise; Outcome; Outcome Measure; Output; Pathway interactions; Patients; Pattern; Perfusion; Physiological; Planet Mars; Play; Population; Population Study; Preparation; Receiver Operator Characteristics; Risk; Role; Route; Severities; Signal Transduction; Spin Labels; Stable Populations; Stenosis; Stroke; Structure of posterior cerebral artery; Symptoms; Techniques; Testing; Thrombolytic Therapy; Time; Tissues; Triage; Vascular Diseases; Vascular blood supply; Venous; Weight; X-Ray Computed Tomography; Xenon; absorption; acronyms; acute stroke; anterior cerebral artery; base; blood flow measurement; cerebrovascular; clinically relevant; digital; digital imaging; human AMID protein; improved; interest; middle cerebral artery; patient oriented; patient population; programs; response

DESCRIPTION (provided by applicant): MOTIVATION Collateral blood flow plays a central role during acute ischemic stroke, and the presence of good collaterals has been linked to improved clinical and radiological outcome measures both with and without treatment. Despite this, the only method to assess adequacy of collaterals currently is invasive and expensive, digital subtraction cerebral angiography (DSA). It would be of tremendous benefit if collaterals could be visualized using a tomographic, non-invasive imaging based modality, so that early treatment decisions could incorporate this critical piece of information. AIMS AND METHODS The overall goal of this new submission is to identify and quantify cerebral blood flow (CBF) delivered via collateral routes using arterial spin labeling (ASL), a non-contrast MRI technique that combines aspects of perfusion and angiography. DSA and xenon CT (xeCT) will act as gold standards for collaterals and CBF, respectively. We aim to show equivalence between DSA and both qualitative and quantitative ASL methods optimized to visualize collaterals in 60 patients with Moyamoya disease. These patients make up an ideal population for this study, as they tend to be young and otherwise healthy, but typically have extensive collateral circulation. We also aim to demonstrate that ASL CBF measurements sensitive to slow flow, such as long post-label delay pseudocon- tinuous ASL and velocity-selective ASL, correlate with xeCT-based CBF in regions supplied by collaterals better than standard ASL and perfusion-weight- ed imaging (PWI)-based CBF. Finally, we will apply the knowledge gained from Moyamoya patients to the much larger and more relevant clinical population of acute ischemic stroke. We will obtain ASL, diffusion-weighted imaging (DWI), and bolus PWI in 60 patients both <24 hours and 3-5 days following acute stroke to determine the ability of ASL collateral CBF imaging to identify tissue at-risk of infarction, using receiver-operator characteristic (ROC) methods. SIGNIFICANCE We believe successful attainment of these aims promises to markedly improve acute stroke care by validating a non-invasive MRI-based method to assess both the presence of collaterals and the amount of CBF they deliver. Our study will lead to better understanding of ASL CBF measurements in patients with severe cerebrovascular disease and greatly enhance the already significant diagnostic power of MRI in acute ischemic stroke. PUBLIC HEALTH RELEVANCE: In the early hours following large vessel occlusion, the ultimate severity of the stroke is largely determined by the ability of collateral flow networks to supply blood to ischemic tissue via circuitous routes that bypass the proximal clot. Ro- bust collateral flow can improve response to thrombolytic therapy and decrease the risk of intracranial hemorrhage. Despite their central importance, collaterals during acute stroke are poorly understood, largely because assessment has required an invasive imaging test, cerebral angiography. This proposal assesses whether a noncontrast MRI perfusion technique, called arterial spin labeling (ASL), can yield important information about collateral flow. ASL images blend features of angiography (dependence on arterial arrival times) and perfusion (the ability to quantify CBF in absolute physiologic units). Recent technical advances and the more widespread introduction of 3T clinical MRI scanners are beginning to bring this technique into the mainstream, as a valuable and robust clinical imaging tool for the evaluation of cerebrovascular disease. To fully characterize the relationship between collateral flow and ASL, we will first study patients with Moyamoya disease. This is a chronic vasculopathy primarily of young people, who are stable enough to undergo MRI in a non-acute setting and who routinely receive cerebral angiography in preparation for possible extracranial-to-intracranial bypass. They make up an ideal population to study extensive collateral flow without the time constraints that surround acute stroke patients. We will then take the information from these studies, and apply the best ASL methods to acute stroke patients. For both groups of patients, we will validate the ASL cerebral blood flow measurements using a gold-standard, stable xenon-enhanced CT. Successful completion of this project will lead to better understanding of ASL CBF measurements in patients with severe cerebrovascular disease and greatly enhance the already significant diagnostic power of MRI in acute ischemic stroke.

描述（由申请人提供）：动机侧支血流在急性缺血性中风期间起着核心作用，良好的侧支血流的存在与治疗或不治疗时临床和放射学结果测量的改善有关。尽管如此，目前评估侧支循环充足性的唯一方法是侵入性且昂贵的数字减影脑血管造影（DSA）。如果可以使用基于断层扫描、非侵入性成像的方式对侧支循环进行可视化，那么早期的治疗决策就可以纳入这一关键信息，这将带来巨大的好处。目的和方法 这项新提交的总体目标是使用动脉自旋标记 (ASL) 来识别和量化通过侧支途径输送的脑血流量 (CBF)，动脉自旋标记是一种结合了灌注和血管造影方面的非对比 MRI 技术。 DSA 和氙气 CT (xeCT) 将分别作为抵押品和 CBF 的黄金标准。我们的目标是证明 DSA 与经过优化以可视化 60 名烟雾病患者的络脉的定性和定量 ASL 方法之间的等效性。这些患者构成了本研究的理想人群，因为他们往往年轻且健康，但通常具有广泛的侧支循环。我们还旨在证明 ASL CBF 测量对慢血流敏感，例如长标签后延迟伪连续 ASL 和速度选择性 ASL，与基于 xeCT 的 CBF 在由侧支提供的区域中相关性优于标准 ASL 和灌注重量- 基于 ed 成像 (PWI) 的 CBF。最后，我们将从烟雾病患者中获得的知识应用于更大且更相关的急性缺血性中风临床人群。我们将在急性卒中后 24 小时内和 3-5 天内获得 60 名患者的 ASL、弥散加权成像 (DWI) 和推注 PWI，以确定 ASL 并行 CBF 成像识别有梗塞风险的组织的能力，使用接收者操作特征（ROC）方法。意义 我们相信，成功实现这些目标有望通过验证基于 MRI 的非侵入性方法来评估侧支循环的存在及其提供的 CBF 量，从而显着改善急性中风护理。我们的研究将有助于更好地了解严重脑血管疾病患者的 ASL CBF 测量，并大大增强 MRI 对急性缺血性中风本已显着的诊断能力。公众健康相关性：在大血管闭塞后的最初几个小时，中风的最终严重程度在很大程度上取决于侧支血流网络通过绕过近端血栓的迂回路径向缺血组织供血的能力。强大的侧支血流可以改善溶栓治疗的反应并降低颅内出血的风险。尽管侧支循环至关重要，但人们对急性中风期间的侧支循环知之甚少，这主要是因为评估需要侵入性成像测试，即脑血管造影。该提案评估了称为动脉自旋标记 (ASL) 的非对比 MRI 灌注技术是否可以产生有关侧支血流的重要信息。 ASL 图像融合了血管造影（取决于动脉到达时间）和灌注（以绝对生理单位量化 CBF 的能力）的特征。最近的技术进步和 3T 临床 MRI 扫描仪的更广泛引入开始使该技术成为主流，作为评估脑血管疾病的有价值且强大的临床成像工具。为了充分了解侧支血流与 ASL 之间的关系，我们将首先研究烟雾病患者。这是一种主要发生于年轻人的慢性血管病变，他们的病情足够稳定，可以在非急性环境下接受 MRI，并且定期接受脑血管造影，为可能的颅外至颅内搭桥术做准备。他们是研究广泛侧支血流的理想人群，不受急性中风患者的时间限制。然后，我们将从这些研究中获取信息，并将最佳的 ASL 方法应用于急性中风患者。对于两组患者，我们将使用金标准、稳定的氙气增强 CT 验证 ASL 脑血流量测量结果。该项目的成功完成将有助于更好地了解严重脑血管疾病患者的 ASL CBF 测量，并大大增强 MRI 对急性缺血性中风本已显着的诊断能力。