Microvascular Measures of Perfusion in Stroke Recanalization

抽象的。缺血性卒中后的脑再通是最好的 恢复大脑的方法。然而，血流的恢复往往伴随着 脑损伤和组织死亡。一种可靠的共同恢复流动的描述 具有抢救价值的脑功能障碍具有临床意义。 核磁共振成像为中风损伤的诊断提供了有用的描述 来自T2、DWI和灌注成像。然而，我们需要改进的方法 血流灌注，以最好地映射和区分血流与组织状态。这个 临床假说脑再灌注是脑血流恢复的过程 抢救大脑的时间窗口，并能够描述这两个方面 再灌流过程对数百次再灌流过程至关重要 每天在全球范围内。 这份新提交的报告的总体目标是确定和改进大脑 动态磁化率对比(DSC)的血流(CBF)技术 磁共振灌注成像(PWI)方法可同时显示血流恢复 再加上与DWI相比最合适的微血管状况 形成临床上有用的代表危险脑组织的DWI-PWI错配 或者是可挽救的大脑。 为了做到这一点，我们将评估用梯度标测灌注的价值- 回波(GRE)和自旋回波(SE)信号一起采集，在多激发，多 ECHO和DSC首过团注造影剂MRI技术。灌流 MAP将与CBF的黄金标准氙气CT(XeCT)值进行比较。我们 目的显示GRE-DSC和SE-DSC与黄金标准的等价性 为了可视化120例中风患者的血管和微血管状况 做了再通手术。我们将获得T1，T2，T2*，扩散加权 120例在术后6-48小时出现的患者的成像(DWI)和团注PWI 并在30天后获得第二次随访研究，作为组织的衡量标准 结果与临床评估相结合。 我们相信，成功实现这些目标有望显著提高 通过验证基于MRI的灌注方法的敏感性来改善急性中风的护理 血管状态和组织微血管状态。这项研究将导致 更好地了解脑梗塞患者的标测血流和微血管状态 严重的脑血管疾病，大大增强了本已意义重大的 MRI更好地标测代谢图对急性缺血性卒中的诊断价值 再灌流后血流灌注不匹配。

ABSTRACT. The recanalization of brain following ischemic stroke is the best means of recovering brain. However, restoration of flow is often accompanied by brain injury and tissue death. A reliable depiction of restoration of flow together with salvageable brain is of clinical significance. Imaging with MRI offers diagnostically useful depictions of stroke injury from T2, DWI, and perfusion imaging. However, we need improved methods of perfusion in order to best map and differentiate flow from tissue status. The clinical hypothesis that reperfusion of brain is a process of restoration of flow in the time window of salvaging brain, and being able to depict both aspects of that reperfusion process are crucial to the hundreds of reperfusion procedures done daily worldwide. The overall goal of this new submission is to identify and improve cerebral blood flow (CBF) techniques from dynamic susceptibility contrast (DSC) perfusion-weighted MRI (PWI) methods that can depict both restoration of flow together with the microvascular status that would optimally compare with DWI to form a clinically useful DWI-PWI mismatch representing brain tissue-at-risk or salvageable brain. To do this, we will assess the value of mapping perfusion with a gradient- echo (GRE) and a spin-echo (SE) signal acquired together in a multi-shot, multi- echo, and DSC first-pass bolus contrast agent MRI technique. The perfusion maps will be compared with a gold-standard xenon CT (xeCT) value of CBF. We aim to show equivalence between GRE- and SE-DSC to the gold-standard in order to visualize vascular and microvascular status in 120 stroke patients having had recanalization procedures. We will obtain T1, T2, T2*, diffusion-weighted imaging (DWI), and bolus PWI in 120 patients presenting at 6-48 hours following reperfusion and obtain a second follow-up study at 30 days as a measure of tissue outcome together with clinical assessments. We believe successful attainment of these aims promises to markedly improve acute stroke care by validating a MRI-based perfusion methods sensitive to both vascular status and tissue microvascular status. This study will lead to better understanding of mapping flow and microvascular status in patients with severe cerebrovascular disease and greatly enhance the already significant diagnostic power of MRI in acute ischemic stroke by better mapping metabolic- perfusion mismatches after reperfusion.