SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY (SPECT)

在这个项目中，SPECT灌注数据将在基线时从对照组和认知障碍的非痴呆受试者中获得，这些受试者将通过临床核心招募并随访一段时间。当受试者越过临床核心定义的特定过渡边界时，将通过SPECT进行纵向评估。SPECT项目的总体目标是确定SPECT数据是否可以用来预测哪些有认知问题的非痴呆个体会发展为进行性认知能力下降，哪些会发展到符合AD标准的程度，哪些会保持稳定。此外，我们将试图确定表征前驱AD的大脑变化的演变，以及这些措施与受试者的临床特征之间的关系。这些目标的基础假设是SPECT灌注数据可以作为阿尔茨海默病（AD）发展过程中神经斑块和神经原纤维缠结积累时发生的神经元损失的间接测量。在提议的资助周期中，我们将使用几种方法分析SPECT数据：(1)MRI引导感兴趣区域（ROI），(2)基于多变量的奇异值分解（SVD）方法，以及(3)广泛使用的基于体素的单变量方法，统计参数映射（SPM99）。三个处理流的结果将相互比较，并与来自其他项目和核心的变量进行比较。此外，我们将试图确定SPECT测量与通过核心和项目获得的同一个体的其他信息之间的关系，包括临床数据，基因型状态，体积MRI和fMRI信号变化。

In this project, SPECT perfusion data will be obtained at baseline from controls and non-demented subjects with cognitive impairments who will be recruited through the Clinical Core and followed over time. Subjects will be evaluated longitudinally with SPECT when they cross specific transition boundaries, as defined by the Clinical Core. The overall goal of the SPECT project is to determine whether SPECT data can be used to predict which non-demented individuals with cognitive problems will develop progressive cognitive decline, which will progress to the point where they meet criteria for AD, and which will remain stable. In addition, we will seek to determine the evolution of brain changes that characterize prodromal AD, and how these measures relate to the clinical characteristics of the subjects. Underlying these goals is the assumption that SPECT perfusion data can serve as an indirect measure of the neuronal loss that occurs when neuritic plaques and neurofibrillary tangles accumulate during the development of Alzheimer's disease (AD). In the proposed funding cycle we will analyze the SPECT data with several methods: (1) MRI guided regions-of-interest (ROI), (2) a multivariate, voxel-based method known as singular value decomposition (SVD), and (3) a widely used voxel-based unvariate method, statistical parametric mapping (SPM99). Results from the three processing streams will be compared with one another and to variables from other projects and cores. In addition, we will seek to determine the relationship between SPECT measures and other information obtained on the same individuals by the cores and the projects, including clinical data, genotype status, volumetric MRI, and fMRI signal change.