Improved Measurement of Celebral Perfusion with MRI

描述(由申请者提供)：该项目广泛的、长期的目标是改善缺血性中风患者的诊断和治疗。在工业化世界中，缺血性中风是导致死亡和残疾的第三大原因。仅在美国，每年就有50万到75万人受到中风的影响。在缺血性中风中，血液凝块会阻塞供大脑的血管。急性缺血性中风可以通过使用溶解血栓的药物治疗(溶栓)来治疗。溶栓已被证明可以减少与中风相关的死亡和残疾，但具有极大的破坏性脑出血(ICH)的风险，这表明需要仔细分流。如果没有预测脑出血的手段，90%以上的中风患者必须拒绝溶栓治疗。有证据表明，以毫升/100g-分钟为单位了解脑血流量有助于预测急性卒中患者脑出血的发生。缺血性卒中治疗的一个主要障碍是缺乏一种广泛可用的方法来量化CBF以进行分类。这促使美国心脏和中风协会建议：“必须进行更多的研究，使这些技术，特别是基于磁共振的方法，能够量化。”我们最近开发了一种新的用于定量脑血流的MRI脉冲序列。我们将在缺血性中风的动物模型以及急性和慢性缺血的患者中验证这种诊断技术。我们将展示qCBF可以用来对患者进行危险分层，以便正常情况下不符合溶栓条件的患者可以安全地使用这种救命疗法进行治疗。这一建议的具体目的是检验以下假设：具体目标1：MRI血流灌注测量可以准确地定量正常犬的脑血流量。具体目的2：MRI血流灌注测量可以准确地定量脑血流量，这是一种犬缺血性卒中模型。具体目的3：MRI测量可预测慢性脑缺血患者的脑血流量。具体目的4：在急性卒中患者中，定量CBF值可以预测溶栓所致的颅内出血。在这项工作成功完成后，我们将开发并验证一种新的MRI方法，该方法可以量化CBF用于急性卒中患者的分诊。

DESCRIPTION (provided by applicant): The broad, long-term objective of this project is to improve the diagnosis and treatment of ischemic stroke patients. Ischemic stroke is the third leading cause of death and disability in the industrialized world. In the US alone, between 500,000 and 750,000 people are affected by stroke each year. In an ischemic stroke, a blood clot blocks a blood vessel feeding the brain. Acute ischemic stroke is treatable through the use of drug therapies that dissolve blood clots (thrombolysis). Thrombolysis has been shown to reduce the death and disability associated with stroke, but carries significant risk of devastating intracerebral hemorrhage (ICH), indicating the need for careful triage. Without a means to predict ICH, thrombolysis must be denied to over 90% of stroke patients. Evidence has shown that knowledge of CBF in ml/100g-min can help predict ICH in acute stroke patients. A major impediment in treatment of ischemic stroke is the lack of a widely available method for quantifying CBF for triage. This has prompted the American Heart and Stroke Association to recommend: "More research must be conducted to make these techniques, especially the MR-based methods, quantifiable". We have recently developed a novel MRI pulse sequence for quantitative CBF. We will validate this diagnostic technique in both animal models of ischemic stoke and in a patients with acute and chronic ischemia. We will show that qCBF can be used to risk stratify patients so that patients who would not normally be eligible for thrombolysis can be safely treated with this lifesaving therapy. The specific aims of this proposal are to test the following hypotheses: Specific Aim 1: MRI measurements of perfusion can accurately quantify CBF in normal canines. Specific Aim 2: MRI measurements of perfusion can accurately quantify CBF a canine model of ischemic stroke. Specific Aim 3: MRI measurements can predict CBF in chronic ischemic patients. Specific Aim 4: In acute stroke patients, quantitative CBF values can predict intracranial hemorrhage resulting from thrombolysis. Upon successful completion of this work we will have developed and validated a new MRI method that quantifies CBF for the triage of acute stroke patients.