MRI OF BRAIN STRUCTURE AND PERFUSION

该项目的总体目标是：1）确定动脉硬化的程度（通过C-IMT测量， R-AV比值与脑灌注、灰质体积和完整性的变化有关 和白色物质（WM），以及2）这种关联与大脑变化的程度， 阿尔茨海默病病理引起的认知障碍。本项目将在高场使用最先进的MRI， 通过对260名受试者进行两次或两次以上的扫描来测量470名受试者大脑中发生的变化。数据将 包括测量灰质和白色物质病变（WML）结构MRI、海马子区域 动脉自旋标记灌注（ASL）MRI以量化脑血流量，以及扩散张量成像（DTI） 来量化白色物质束的完整性。图像分析将使用：用途：配准和空间 标准化、分割、纤维束成像、基于体素的分析和感兴趣区域选择，以测试 统计学上，以下假设横截面和纵向（预测的变化， 结果变量）： 1.）的人。动脉硬化与脑灌注减少、WML和腔隙性梗死、GM萎缩和 WM束的各向异性分数降低，尤其是上级纵束和枕束 额束 2.）的情况。白色病变（WML，尤其是额叶的室周WML）和腔隙性梗死 与额叶灌注减少和白色束FA减少相关，尤其是上级 纵束和枕额束。 3.）第三章海马子区域的萎缩（AD病理学的标志物）与海马的灌注减少相关。 后扣带回GM和扣带回束WM的FA减少。 4.）的情况。区域：额叶灌注、额叶白色物质FA和额叶GM体积相关 海马体积、后扣带回灌注、扣带回束FA 与记忆功能有关。 最后，我们将探讨PIB摄取（淀粉样蛋白负荷）和FDG摄取与结构， MRI检测脑灌注和DTI变化。

The overall goals of this project are 1) to determine the extent to which arteriosclerosis (measured by C-IMT, R-AV ratio) is associated with changes of brain perfusion, and the volume and integrity of gray matter (GM) and white matter (WM) and 2) the extent to which this association relates to the changes in brain and cognition caused by Alzheimer's disease pathology. This project will use state of the art MRI at high field to measure changes occurring in the brains of 470 subjects with two or more scans in 260 subjects. Data will include structural MRI to measure gray matter and white matter lesions (WMLs), hippocampal subfields, arterial spin labeled perfusion (ASL) MRI to quantify cerebral blood flow, and diffusion tensor imaging (DTI) to quantify measures of integrity of white matter tracts. Image analysis will use: registration and spatial normalization, segmentation, tractography, voxel based analyses and region of interest selection, to test statistically the following hypotheses cross sectionally and longitudinally (prediction of change in the outcome variable): 1.) Arteriosclerosis correlates with reduced brain perfusion, WMLs and lacunar infarcts, GM atrophy, and reduced fractional anisotropy of WM tracts, especially the superior longitudinal fasciculus and the occipital frontal tracts. 2.) White matter lesions (WMLs, especially periventricular WMLs in the frontal lobe) and lacunar infarcts correlate with reduced perfusion of frontal lobe and reduced FA of white matter tracts, especially the superior longitudinal fasciculus and occipital frontal tract. 3.) Atrophy of hippocampal subfields (a marker of AD pathology) correlates with reduced perfusion of the posterior cingulate GM and reduced FA of the cingulum tract WM. 4.) Regions of: frontal lobe perfusion, FA of frontal lobe white matter, and volume frontal lobe GM correlate with executive function while hippocampal volumes, posterior cingulate perfusion, and FA of cingulum tract correlate with memory function. Finally, we will explore the relationship of PIB uptake (amyloid load), and FDG uptake, to the structural, perfusion, and DTI changes detected by MRI.