Imaging Cerebral Small Vessels in Vascular Cognitive Impairment and Dementia (VCID)

项目摘要/摘要 血管对认知损害和痴呆的贡献(VCID)越来越被认为是 这是导致痴呆症的重要原因。脑部小血管疾病(CSVD)是最常见的血管病因 痴呆症是混合性痴呆症的主要诱因，也是全球约五分之一中风的原因。 然而，cSVD的潜在机制仍然知之甚少。CSVD中巨大的知识缺口是 部分原因是大脑小血管，包括小动脉、毛细血管和小静脉，是现有的 活体成像技术。在过去的几年里，我们集团带头开发了一种新的 用于脑可视化、分割和量化的高分辨率黑血MRI技术 小血管，包括豆纹和浅穿通动、静脉。这项技术提供了 各向同性~0.5 mm的空间分辨率，由于回声序列较长，对小血管有足够的流动抑制， 在临床野强为3T时，可在~10min内实现近全脑覆盖。我们进一步开发了一种 综合三维分析流水线定量脑小血管的形态和密度 尺寸在几百微米左右。此外，我们在开发方面有长期的记录 以及应用动脉自旋标记(ASL)技术来量化微血管灌注--这是一个关键 CSVD的生理参数和潜在的生物标志物。我们的初步数据显示预期 随着年龄、血管风险的增加，小血管形态和密度以及微血管灌注的变化 和轻度认知障碍(MCI)，支持使用小血管形态/密度和 微血管血流灌注作为脑血管病和脑血管病的影像标志物。该项目的主要目标是进一步 脑小血管标测与量化采集方案及分析流水线的优化 采用3T黑血和ASL磁共振成像，系统评价小血管的各项指标 形态/密度和血流灌注作为VCID影像生物标志物在200名多民族纵向队列中的研究 小血管VCID丰富的受试者。特别是，我们的研究将招募50名亚洲人 美国人是美国增长最快的人口之一，但在ADRD中的代表性严重不足 研究。该项目预计将产生一套强大的成像工具，用于全面 表征大脑小血管的形态和功能，以及填补这一重要空白 ADRD研究中亚裔美国人的健康差距。

Project Summary/Abstract Vascular contributions to cognitive impairment and dementia (VCID) is becoming increasingly recognized as an important cause of dementia. Cerebral small vessel disease (cSVD) is the most common vascular cause of dementia, a major contributor to mixed dementia, and the cause of about one fifth of all strokes worldwide. However, the underlying mechanisms of cSVD remain poorly understood. The large knowledge gap in cSVD is partly because cerebral small vessels, including arterioles, capillaries and venules, are inaccessible to existing in vivo imaging technologies. During the past few years, our group has spearheaded the development of a new high-resolution black-blood MRI technique for the visualization, segmentation and quantification of cerebral small vessels including lenticulostriate and superficial perforating arteries and venules. This technique offers an isotropic ~0.5mm spatial resolution, adequate flow suppression for small vessels due to the long echo train, and near whole-brain coverage in ~10min at clinical field strength of 3T. We further developed a comprehensive 3D analysis pipeline for quantifying the morphology and density of cerebral small vessels with sizes on the order of a few hundred microns. In addition, we have a longstanding track record in developing and applying arterial spin labeling (ASL) techniques for quantifying microvascular perfusion – a key physiological parameter and potential biomarker for cSVD. Our preliminary data demonstrated expected changes in small vessel morphology and density as well as microvascular perfusion with aging, vascular risks and mild cognitive impairment (MCI), supporting the use of metrics of small vessel morphology/density and microvascular perfusion as imaging markers of cSVD and VCID. The primary goals of this project are to further optimize the acquisition protocol and analysis pipeline for mapping and quantifying cerebral small vessels using black-blood and ASL MRI at 3T, and to systematically evaluate metrics of small vessel morphology/density and perfusion as imaging biomarkers of VCID in a multiethnic longitudinal cohort of 200 subjects that are enriched for small vessel VCID. In particular, our study will enroll a cohort of 50 Asian Americans who are among the fastest growing populations in the US but are highly underrepresented in ADRD research. This project is expected to result in a powerful suite of imaging tools for comprehensive characterization of the morphology and function of cerebral small vessels, as well as to fill in the important gap in health disparities of Asian Americans in ADRD research.