LOCALIZATION OF CEREBRAL DYSFUNCTION IN DEMENTIA (AD)

拟议研究的总体目标是推动当前 可用的神经成像技术，以促进他们的 应用于以认知和行为为特征的障碍 功能障碍。这项建议的具体目的是改善形象 磁共振解剖图像与功能性正电子发射计算机断层成像结合的分析方法 用H_215O获取局部脑血流图像及其应用 产生认知信号的行为/生理技术 对了解痴呆症患者的局限性功能障碍有价值 病人。 图像分析的发展有三个主要组成部分 方法：(1)图像配准：改进的基于面元的配准方法 将开发拟合技术来在空间上配准一组 包含一系列PET发射图像的MR图像，这些图像由 在不同条件下向同一受试者注射H_215O 行为/生理条件；(2)图像内插：准确 用于脑表面形状和脑表面形状的内插方案 脑图像的强度级别将使用动态 弹性力场模型生成更完整的3-D脑图像数据 集合；以及(3)图像减法：将开发新技术用于 通过以下方式检测、定位和增强认知信号 从刺激下的图像中减去基线状态下的PET图像 州政府。检测到的认知信号也将在配准中 与MR图像提供的解剖图相匹配。 在开发行为/生理技术方面，有三个程序将 用于产生用于理解的认知诱导信号 痴呆患者的局限性功能障碍：(1)改良Sternberg 程序，其中与短期记忆有关的信号将 评估；(2)序列反应时间程序，其中信号与 对内隐记忆进行评估；(3)言语理解 程序，这将被用来加强全球脑流动。 这项研究的结果将对确定 阿尔茨海默病和痴呆对神经系统的影响 相关的退行性疾病并有助于改善 对高血压病的病理生理机制的认识 退化过程。

The broad objective of the proposed research is to advance currently available neuro-imaging techniques in order to facilitate their application to disorders characterized by cognitive and behavioral dysfunction. The specific aims of this proposal are to improve image analysis methods for integrating anatomical MR images and functional PET images of regional cerebral blood flow obtained by using H215O and apply behavioral/physiological techniques to generate cognitive signals that are valuable in understanding localized dysfunction in demented patients. There are three major components in the development of image analysis methods: (1) Image registration: Improved methods based on surface- fitting techniques will be developed for spatially registering a set of MR images with a series of PET emission images that are acquired by injecting H215O to the same subject under different behavioral/physiological conditions; (2) Image interpolation: Accurate interpolation schemes for both the shapes of the brain surface and the intensity levels of brain images will be developed using an dynamic elastic force field model to generate more complete 3-D brain image data sets; and (3) Image subtraction: New techniques will be developed for detecting, localizing, and enhancing the cognitive signals by subtracting PET images at a baseline state from images at a stimulus state. The detected cognitive signals will be also be in registration with the anatomical map provided by MR images. In developing behavioral/physiological techniques, three procedures will be used to generate cognitively induced signals for understanding localized dysfunction in demented patients: (1) Modified Sternberg procedure, in which signals related to short-term memory will be assessed; (2) Serial reaction time procedure, in which signals related to implicit memory will be evaluated; and (3) Verbal comprehension procedure, which will be employed to enhance global cerebral flow. The results of this research will be of value in determining the neuronal systems affected in the dementia of Alzheimer's disease and related degenerative disorders and contribute to an improved understanding of the pathophysiological mechanisms involved in the degenerative processes.