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

项目总结/摘要 然而，心血管危险因素与阿尔茨海默病和相关痴呆症有关， 心-脑血液动力学耦合的潜在机制还不清楚。主动脉硬化 与痴呆风险增加有关。除了通常与衰老有关的大脑变化外， 脑血管疾病和阿尔茨海默病也影响血管功能和神经元结构。然而，在这方面， 心脏和大脑通常不会在同一次MRI检查中进行评估，而是在单独的扫描过程中进行评估， 高度专业化的方案集中于心血管或脑成像。最近，我们的团队和其他 已经建立了先进的MRI技术，以捕获诸如心血管和脑血管的测量结果， 血液动力学和脑结构。测量主动脉血液动力学（例如，脉搏波 速度），以及颅内搏动和脑血管疾病相关的脑异常 和阿尔茨海默病，将提供关键的见解有关的血液动力学机制。的 拟议的研究将使用先进的MRI技术对心脑血流动力学进行全面分析 偶合器.该项目将利用心血管成像的新发展，特别是使用4D流动MRI， 能够对复杂的3D血液动力学进行全面表征，例如血流速度、反向流动标测 和主动脉脉搏波速度。高度加速的4D Flow MRI的方法学进展使集成成为可能 心血管和颅内4D Flow MRI，在单一MRI中进行脑部定量结构分析 考试这种将心血管和脑血管4D流动MRI与定量脑成像（即“心脑血管成像”）相结合的方法， MRI”）将用于分析衰老和阿尔茨海默病中的血液动力学耦合。这项提案的目的是 是使用新的心脑MRI系统地评估正常衰老中的血液动力学耦合关系， 和高血压，并将这项技术应用于阿尔茨海默病的初步研究。在目标1和2中， MRI将在健康成人和中年及晚年高血压患者中进行评估，以确定 正常衰老中心脑MRI测量与高血压如何加重脑损害之间的关系 随着年龄的变化。在目标3中，心脑MRI将应用于阿尔茨海默病的初步研究，以检查 初步的关系，并帮助规划未来的研究。该K 01将提供临床和神经成像方面的培训 老龄化和老年痴呆症的方面，以进一步建立一个独立的研究计划的目标 专注于认知老化和痴呆症中的心脑血流动力学耦合，包括由 老年痴呆症

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.