Improved Measurement of Cerebral Perfusion with MRI

描述（由申请人提供）：本项目的长期目标是提高缺血性脑卒中患者的诊断和治疗。缺血性中风是工业化国家中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，血块阻塞了为大脑供血的血管。急性缺血性中风可以通过药物治疗来溶解血凝块（溶栓）。已证明溶栓可减少与中风相关的死亡和残疾，但具有严重的破坏性脑出血（ICH）风险，表明需要仔细分诊。由于没有预测脑出血的手段，90%以上的脑卒中患者必须拒绝溶栓。有证据表明，了解毫升/100g-min的脑血流可以帮助预测急性脑卒中患者的脑出血。缺血性脑卒中治疗的一个主要障碍是缺乏一种广泛可用的量化脑血流分诊的方法。这促使美国心脏病和中风协会建议：“必须进行更多的研究，使这些技术，特别是基于核磁共振的方法，可量化。”我们最近开发了一种新的MRI脉冲序列定量CBF。我们将在缺血性中风的动物模型和急性和慢性缺血患者中验证这种诊断技术。我们将证明qCBF可用于对患者进行风险分层，以便通常不适合溶栓治疗的患者可以安全地接受这种挽救生命的治疗。本提案的具体目的是验证以下假设：具体目的1:MRI灌注测量可以准确量化正常犬的脑血流。目的2:MRI灌注测量可以准确量化犬缺血性脑卒中模型的脑血流。特异性目的3:MRI测量可以预测慢性缺血性患者的脑血流。特异性目的4：在急性脑卒中患者中，定量CBF值可以预测溶栓引起的颅内出血。在成功完成这项工作后，我们将开发并验证一种新的MRI方法，用于量化急性卒中患者的脑血流分诊。

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.