PARTIAL VOLUME CORRECTION IN PET IMAGING IN AGING

在过去的十年里，正电子发射的技术进步 断层摄影（PET）成像提供了以前无法获得的信息 关于正常衰老过程中的神经化学因素， 在老年人神经系统疾病包括阿尔茨海默病中的作用。 尽管有这些进步，PET成像受到需要校正的限制。 部分体积平均的影响。 考虑到这些影响， 关键;没有它，大脑代谢率或受体结合的改变 可能被解释为大脑化学的内在变化，而事实上， 他们出现由于脑萎缩。这个项目是一个多学科的 一个分析的发展，验证和实施的方法 PET成像中部分体积效应的全脑校正模型。 本计画的目标是将此模型应用于区域脑的评估 灰质组织中的放射性浓度。 验证方法为 使用计算机生成的PET图像描述，所述PET图像来源于组织分割 MRI图像、逼真的琼脂糖凝胶脑模型和离体PET 狒狒的测量。 验证后，将应用该方法 使用F-18测量局部脑葡萄糖代谢率 使用C-11的氟脱氧葡萄糖和局部脑μ阿片受体 卡芬太尼 部分体积校正方法对 脑葡萄糖代谢和μ阿片受体的测量是一种 健康人和阿尔茨海默病患者的年龄功能 疾病 通过消除部分容积效应的混杂变量 在这些研究中， 葡萄糖代谢和μ阿片受体，我们希望这将导致 发现正常衰老和阿尔茨海默氏症的新变化模式 疾病

Within the past decade, technological advances in positron emission tomography (PET) imaging have provided information previously unobtainable about the neurochemical factors involved in normal aging as well as their role in neurological diseases of the elderly including Alzheimer's Disease. Despite these advances, PET imaging is limited by the need to correct for effects of partial volume averaging. Consideration of these effects is key; without it, alterations in brain metabolic rates or receptor binding may be interpreted as intrinsic changes in brain chemistry when, in fact, they arise due to brain atrophy.This project is a multidisciplinary approach to the development, validation and implementation of an analytic model for whole brain correction of partial volume effects in PET imaging. The goal of this project is to apply the model to estimate regional brain radioactivity concentrations in gray matter tissue. Validation methods are described using computer generated PET images derived from tissue segmented MRI images, realistic agarose gel brain phantoms and PET in ex vivo measurements in baboons. Following validation the method will be applied to measurements of regional brain glucose metabolic rate using F-18 fluorodeoxyglucose and regional brain mu opiate receptors using C-11 carfentanil. The impact of the partial volume correction method on measurements of brain glucose metabolism and mu opiate receptors is a function of age in healthy human subjects and in patients with Alzheimer's Disease. By eliminating the confounding variable of partial volume effect in these studies, the result is more accurate quantification of brain glucose metabolism and mu opiate receptors, which we hope will lead to the discovery of new patterns of change in normal aging and Alzheimer's Disease.