Heart-brain MRI for the evaluation of hemodynamic coupling in aging and Alzheimer's disease

项目摘要/摘要 然而，心血管风险因素与阿尔茨海默病和相关痴呆有关， 心脑血流动力学耦合的机制还不是很清楚。主动脉硬化已经是 与痴呆症风险增加有关。除了通常与衰老相关的大脑变化外， 脑血管疾病和阿尔茨海默病也会影响血管功能和神经元结构。然而， 心脏和大脑通常不会在同一次MRI检查中进行评估，而是在单独的扫描会话中进行 高度专业化的方案侧重于心血管或大脑成像。最近，我们小组和其他人 已经建立了先进的核磁共振技术来捕捉心脑血管等指标 血流动力学和脑结构在同一个MRI检查。测量主动脉血流动力学(例如，脉搏波 速度)，以及与脑血管疾病相关的颅内搏动和脑异常 和阿尔茨海默病，将提供关于潜在的血流动力学机制的关键见解。这个 拟议的研究将使用先进的核磁共振技术对心脑血流动力学进行综合分析 耦合。该项目将利用心血管成像的新发展，特别是使用4D Flow MRI， 能够全面描述复杂的3D血流动力学，如血流速度、反向血流图 和主动脉脉搏波速度。高速加速4D Flow MRI的方法学进展使集成成为可能 心血管和颅内4D血流MRI与脑的定量结构分析在单个MRI中的应用 考试。这种结合了心脑血管4D Flow MRI和定量脑成像(即心-脑 MRI“)将用于分析衰老和阿尔茨海默病的血流动力学耦合。这项提案的目标是 是利用新的心脑磁共振成像系统地评估正常衰老时的血流动力学耦合关系， 和高血压，并将这项技术应用于阿尔茨海默病的试点研究。在目标1和目标2中，心-脑 将对健康成年人和中老年高血压患者进行核磁共振评估，以确定 正常老年人心脑MRI测量与高血压加重脑损伤的关系 随着年龄的增长而变化。在目标3中，心脏-大脑核磁共振将应用于阿尔茨海默病的初步研究，以检查 初步建立关系，并帮助规划未来的研究。这款K01将提供临床和神经影像方面的培训 老龄化和阿尔茨海默病的各个方面，以促进建立独立研究计划的目标 重点研究认知老化和痴呆的心-脑血流动力学耦合，包括由 阿尔茨海默氏症。

Project Summary/Abstract Cardiovascular risk factors have been implicated in Alzheimer's disease and related dementias, however, mechanisms underlying heart-brain hemodynamic coupling are not well understood. Aortic stiffening has been associated with increased dementia risk. In addition to brain changes typically associated with aging, cerebrovascular disease and Alzheimer's disease also affect vascular function and neuronal structure. However, the heart and brain are not usually evaluated in the same MRI exam, rather, in separate scanning sessions with highly specialized protocols focused on either cardiovascular or brain imaging. Recently, our group and others have established advanced MRI techniques to capture measures such as cardio- and cerebrovascular hemodynamics and brain structure in the same MRI exam. Measuring aortic hemodynamics (e.g., pulse wave velocity), together with intracranial pulsatility and brain abnormalities associated with cerebrovascular disease and Alzheimer's disease, will provide critical insights concerning underlying hemodynamic mechanisms. The proposed research will use advanced MRI techniques for comprehensive analysis of heart-brain hemodynamic coupling. This project will leverage new developments in cardiovascular imaging, particularly using 4D flow MRI, that enable full characterization of complex 3D hemodynamics, such as blood flow velocity, reverse flow mapping and aortic pulse wave velocity. Methodological advances in highly accelerated 4D flow MRI enable integration of cardiovascular and intracranial 4D flow MRI with quantitative structural analysis of the brain in a single MRI exam. This combined cardio- and cerebrovascular 4D flow MRI with quantitative brain imaging (i.e. “heart-brain MRI”) will be used to analyze hemodynamic coupling in aging and Alzheimer's disease. The goal of this proposal is to use novel heart-brain MRI to systematically evaluate hemodynamic coupling relationships in normal aging, and hypertension, and apply this technique in a pilot study of Alzheimer's disease. In Aims 1 and 2, heart-brain MRI will be evaluated in healthy adults and those with hypertension at both midlife and later life, to determine relationships between heart-brain MRI measures in normal aging and how hypertension may exacerbate brain changes with aging. In Aim 3, heart-brain MRI will be applied in a pilot study of Alzheimer's disease to examine preliminary relationships and help plan future studies. This K01 will provided training in clinical and neuroimaging aspects of aging and Alzheimer's disease to further the objective of building an independent research program focused on heart-brain hemodynamic coupling in cognitive aging and dementia, including that caused by Alzheimer's disease.