Imaging Core

我们假设阿尔茨海默病（AD）有一个临床前阶段，在这个阶段中，脑组织中 淀粉样蛋白和β-淀粉样蛋白沉积物的积累预示着神经元的逐渐发病 功能障碍、细胞丧失和痴呆。虽然淀粉样蛋白在脑损伤发生中的确切作用仍然是 虽然目前尚不清楚，但澄清AD之前淀粉样蛋白沉积的确切时间将非常有助于 了解AD的生物学起源并设计适当的干预措施。脑成像提供了 一个窗口，许多假设的生化，功能和解剖学的变化，在AD。用正电子 使用[11 C]PIB的发射断层扫描（PET），可以通过以下方法估计β-淀粉样蛋白斑块的密度： 对PIB结合位点进行成像。利用使用[18F]FDG的PET，有可能从 代谢活动的测量。最后，通过磁共振成像（MRI），随着时间的推移， 在区域和全球大脑测量中进行量化。这是我们的前提，通过检查时间和 这三个措施之间的空间相互关系的重要见解将获得在 AD的病理生理学 通过将数据与CSF生物标志物相结合，进一步增强了这些成像生物标志物的价值 以及临床和心理测量数据。为了实现这些目标，成像核心将提供两个关键支持 目标1：监督所有图像数据的收集。这些数据包括MR扫描 PET FDG扫描用于代谢，PET PIB扫描用于β-淀粉样斑块成像。 目的2：执行图像处理和分析，从图像数据中提取生物学相关指标 集这些措施包括全脑体积和皮质和皮质下区域的灰色措施 物质体积、相对葡萄糖代谢和β-淀粉样蛋白斑块沉积的PIB衍生估计。

We hypothesize that Alzheimer's disease (AD) has a preclinical stage in which elevated levels of brain amyloid protein and accumulation of beta-amyloid deposits foreshadow the gradual onset of neuronal dysfunction, cell loss and dementia. While the exact role of amyloid in the initiation of brain damage is still unclear, clarifying the exact timing of amyloid deposition that precede AD would be extremely helpful in understanding the biological origins of AD and in designing appropriate interventions. Brain imaging provides a window into many of the hypothesized biochemical, functional and anatomic changes in AD. With Positron Emission Tomography (PET) using [11C]PIB it is possible to estimate the density of beta-amyloid plaques by imaging the PIB binding sites. With PET using [18F]FDG it is possible to estimate neuronal function from measures of metabolic activity. Finally, with magnetic resonance imaging (MRI) volume loss over time can be quantified in regional and global brain measures. It is our premise that by examining the temporal and spatial interrelationships between these three measures important insights will be gained in the pathophysiology of AD. The value of these imaging biomarkers are further enhanced by combining the data with CSF biomarkers and clinical and psychometric data. Towards these goals, the Imaging Core will provide two key support activities to the DIAN effort: Aim 1: Oversee the collection of all image data. This data includes MR scans for morphometrics, PET FDG scans for metabolism and PET PIB scans for imaging beta-amyloid plaques. Aim 2: Perform image processing and analysis to extract biologically relevant measures from the image data set. These measures include whole brain volume and cortical and subcortical regional measures of gray matter volume, relative glucose metabolism and PIB-derived estimates of beta-amyloid plaque deposition.