Imaging Core

我们假设阿尔茨海默病(AD)有一个临床前阶段，在这个阶段中大脑水平升高 淀粉样蛋白和β-淀粉样沉积的堆积预示着神经元的逐渐发病 功能障碍、细胞丢失和痴呆症。虽然淀粉样蛋白在启动脑损伤中的确切作用仍然是 尚不清楚，澄清AD之前淀粉样蛋白沉积的确切时间将对 了解阿尔茨海默病的生物学起源，并设计适当的干预措施。脑成像提供了 了解AD中许多假想的生化、功能和解剖变化的窗口。用正电子 使用[11C]PIB的发射断层扫描(PET)可以通过以下方法估计β-淀粉样斑块的密度 成像PIB结合部位。对于使用[18F]FDG的PET，有可能从 代谢活动的衡量标准。最后，使用磁共振成像(MRI)，随着时间的推移，体积损失可以 在区域和全球大脑测量中进行量化。我们的前提是，通过考察时间和 这三个度量之间的空间相互关系将在 阿尔茨海默病的病理生理学。 通过将数据与脑脊液生物标记物相结合，这些成像生物标记物的价值进一步增强 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 DIAN工作的活动：目标1：监督所有图像数据的收集。这些数据包括磁共振扫描 对于形态计量学，PET FDG扫描新陈代谢，PET PIB扫描成像β淀粉样斑块。 目标2：进行图像处理和分析，以从图像数据中提取与生物相关的测量 准备好了。这些测量包括全脑体积以及皮质和皮质下区域的灰度值。 物质体积、相对葡萄糖代谢和PIB得出的β-淀粉样斑块沉积的估计。

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.