MRI of Intracranial Atherosclerosis

描述(申请人提供)：美国每年发生超过780,000例中风，其中至少125,000例与颅内动脉粥样硬化(ICAD)直接相关。尽管ICAD带来了重要后果，但其流行率仍不清楚。传统的ICAD诊断依赖于血管造影术测量的狭窄程度；然而，在其他血管床中，当血管通过重塑适应斑块时，管腔狭窄不是斑块负荷的不良指标。最近，使用高分辨率磁共振成像在颅外斑块中显示了不依赖管腔评估而在体内检测和表征斑块的能力。我们建议开发高分辨率MRI技术来表征ICAD的独特特征。这将在NIH资助的一项基于人群的研究中实施，该研究名为社区动脉粥样硬化风险神经认知研究(ARIC-NCS)，旨在调查ICAD在美国的患病率以及导致其发展和中风的因素。在这笔赠款的K99培训阶段，我将 由一支具有神经放射学、神经学、病理学、核磁共振物理学和流行病学专业知识的杰出导师团队监督。培训将通过课程作业、辅导性研究和进度评估进行。我的指导研究的主要目标是确定ICAD的患病率，并检查ICAD狭窄和负担与危险因素和血管标志物的关系。在独立阶段(R00)，我将应用从第一个授权期(K99)获得的知识来确定ICAD斑块成分的特征，并确定这些成分与缺血性中风的相关性。我的总体假设是，高分辨率磁共振血管壁和斑块成像将提高我们对中风风险分层的能力，从而使初级中风预防和治疗的新策略成为可能。约翰霍普金斯大学的培训环境特别适合这项研究，因为它提供了使用最先进的仪器和基础设施的途径，并拥有长期支持临床研究的记录。相关性：用于表征颅内动脉粥样硬化斑块形态和成分的新的MRI方法将对缺血事件和病变进展的风险进行分层。从动脉粥样硬化的高分辨率磁共振成像中获得的信息对于改进初级卒中预防和治疗的策略是有价值的。

DESCRIPTION (provided by applicant): Over 780,000 strokes occur annually in the U.S. with at least 125,000 directly related to intracranial atherosclerosis (ICAD). Despite the important consequences of ICAD, its prevalence remains unclear. Traditional ICAD diagnosis has depended on stenosis measured by angiography; however, in other vascular beds, lumen narrowing is a poor indicator of plaque burden when vessels accommodate plaques by remodeling. The ability to detect and characterize plaque in vivo without relying on lumen assessment has recently been shown in extracranial plaque using high-resolution MRI. We propose to develop high-resolution MRI techniques to characterize the unique features of ICAD. This will be implemented in an NIH-funded population-based study, the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS), to investigate ICAD prevalence in the US and factors that lead to its development and stroke. In the K99 training phase of this grant, I will be supervised by an outstanding team of mentors with expertise in neuroradiology, neurology, pathology, MRI physics and epidemiology. Training will be conducted via course work, mentored research, and progress reviews. The major objective of my mentored research is to determine ICAD prevalence, and examine ICAD stenosis and burden in relation to risk factors and vascular markers. In the independent phase (R00), I will apply knowledge gained from the first grant period (K99) to characterize ICAD plaque components and determine associations of these components with ischemic stroke. My overall hypothesis is that high- resolution MRI vessel wall and plaque imaging will improve our ability to stratify stroke risk, thereby enabling new strategies for primary stroke prevention and treatment. The training environment at Johns Hopkins is especially well-suited for this research since it offers access to state-of-the art instrumentation and an infrastructure with a long track-record of supporting clinical research. Relevance: New MRI methodologies for characterizing intracranial atherosclerotic plaque morphology and composition will stratify risk for ischemic events and lesion progression. Information obtained from high resolution MRI of atherosclerosis can be valuable in refining strategies for primary stroke prevention and treatment.