Quantitative ASL MR angiography and perfusion imaging for cerebral revascularization

项目总结/摘要 脑血管疾病是全球死亡和残疾的主要原因之一。脑 血运重建，特别是外科血运重建，已经发展成为治疗血管性心脏病的有效外科治疗方法。 慢性脑血管疾病的管理，如烟雾病，复杂动脉瘤， 选择颈动脉狭窄闭塞性疾病，以改善脑血流动力学，降低卒中风险。 尽管如此，最佳的手术计划仍然不清楚，因为各种血运重建技术可以 考虑了迄今为止，血运重建策略的选择主要基于主观解释 在风险区域的流量需求。这导致了可变的、主观的临床实践， 存在血液动力学相关术后并发症的风险，显著影响临床结局。一 血运重建前后脑血流动力学的分段和定量表征是 有必要客观化流程要求，标准化和改善病人护理。然而，现有的 临床成像模态能够提供高时空分辨率的血管造影图像 在没有造影剂的情况下，从单个动脉段获得定量血液动力学信息。动脉自旋 标记（ASL）具有吸引人的功能，可以评估灌注和血管造影 数量上。基于我们在ASL 4D MRA和ASL开发方面的成功记录， 灌注成像，本项目的目标是开发和评估一种易于实施的非侵入性ASL 一套由先进的4D MRA和灌注区域标测组成的套件，用于定量评估大脑 脑血管重建前后个体动脉和下游组织的血液动力学。在Aim中 1.我们将开发和优化一种新的快速高时空分辨率4D MRA技术（<5分钟）。在 目标2，我们将开发和验证脑血流动力学量化的后处理算法， 血管区域与4D MRA和随机血管编码ASL。通过利用丰富的临床资源 南加州大学血管重建中心，在目标3中，我们将定量评价围手术期血流动力学， 接受脑血运重建并研究血运重建相关 血流动力学变化与临床结局。该项目的成功完成将导致一个强大的， 无创、灵活和定量的ASL MRI套件，扫描时间为10分钟，可随时纳入 临床MRI设置。所提出的技术可以是非常有价值的，作为一个潜在的成像工具， 定量评价脑血管重建中的流量需求。

PROJECT SUMMARY/ABSTRACT Cerebrovascular disease is one of the leading causes of death and disability worldwide. Cerebral revascularization, especially surgical revascularization, has evolved as an effective surgical therapy for the management of chronic cerebrovascular diseases such as moyamoya disease, complex aneurysms, and selected carotid steno-occlusive disease to improve the cerebral hemodynamics and reduce the risk of stroke. Nonetheless, optimal surgical planning is still unclear as a variety of revascularization techniques can be considered. To date, the choice of revascularization strategy is primarily based on the subjective interpretation of flow demands in the at-risk territory. This results in a variable, subjective clinical practice that places patients at risk for hemodynamics-related postoperative complications, significantly impacting the clinical outcomes. A segmented and quantitative characterization of cerebral hemodynamics pre- and post-revascularization is necessary to objectify flow requirements, standardize and improve patient care. However, none of the existing clinical imaging modalities are able to provide high spatiotemporal resolution angiographic images with quantitative hemodynamic information from individual arterial segments without contrast agents. Arterial spin labeling (ASL) possesses appealing features that allow for the assessment of both perfusion and angiography quantitatively. Building upon our successful track record on the development of ASL 4D MRA as well as ASL perfusion imaging, the goal of the present project is to develop and evaluate an easily-carry-out noninvasive ASL suite consisting of advanced 4D MRA and perfusion territorial mapping to quantitively assess cerebral hemodynamics from individual arteries and downstream tissue pre and post-cerebral revascularization. In Aim 1, we will develop and optimize a novel rapid high spatiotemporal resolution 4D MRA technique (<5minutes). In Aim2, we will develop and validate post-processing algorithms for cerebral hemodynamic quantification and vascular territories with 4D MRA and random vessel-encoded ASL. By leveraging the rich clinical resource from the USC Revascularization Center, in Aim 3, we will quantitively evaluate perioperative hemodynamics on patients who undergo cerebral revascularization and study the association of revascularization-related hemodynamic change with clinical outcomes. The successful completion of this project will lead to a robust, noninvasive, flexible, and quantitative ASL MRI suite within 10 min scan time that is ready to be incorporated into clinical MRI settings. The proposed technique can be highly valuable as a potential imaging tool for the quantitative evaluation of flow demands in cerebral revascularization.