Microvascular Measures of Perfusion in Stroke Recanalization

摘要。缺血性脑卒中后的脑血管再通是最好的 恢复大脑的方法。然而，恢复流动往往伴随着 脑损伤和组织死亡。一起恢复流动的可靠描述 具有临床意义。 磁共振成像提供了诊断有用的预防中风损伤 T2弥散加权成像和灌注成像然而，我们需要改进的方法， 灌注，以便最好地映射和区分流动与组织状态。的 临床假设脑再灌注是一个恢复血流的过程， 挽救大脑的时间窗口，并能够描述这两个方面， 再灌注过程是至关重要的数百个再灌注程序完成 每日全球 这项新提交的总体目标是识别和改善大脑 动态磁敏感对比（DSC）血流（CBF）技术 灌注加权MRI（PWI）方法可以描述血流恢复 以及与DWI最佳比较的微血管状态 形成临床上有用的DWI-PWI不匹配，代表风险脑组织 或可挽救的大脑 为此，我们将评估梯度灌注标测的价值- 回波（GRE）和自旋回波（SE）信号一起在多激发、多激发和多激发中采集。 超声和DSC首过团注造影剂MRI技术。灌注 图将与CBF的金标准氙CT（xeCT）值进行比较。我们 旨在证明GRE和SE-DSC与金标准之间的等效性， 为了观察120名中风患者的血管和微血管状态， 做了血管再通手术我们将获得T1、T2、T2*、弥散加权 120例患者在术后6-48小时就诊， 再灌注，并在30天时获得第二次随访研究作为组织测量 结果与临床评估。 我们认为，成功实现这些目标， 通过验证基于MRI灌注方法敏感性来改善急性卒中护理 与血管状态和组织微血管状态有关。这项研究将导致 更好地理解患者的标测血流和微血管状态 严重的脑血管疾病，大大提高了已经显着 通过更好地绘制代谢图， 再灌注后灌注不匹配。

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.