阿尔茨海默病和轻度认知功能障碍脑网络异常模式——基于多模态磁共振成像技术的研究

Alzheimer disease (AD) is one of the major diseases which seriously threat to human health. Mild cognitive impairment (MCI) is the early stage of AD. The disconnection syndrome is an important hypothesis of AD pathogenesis. In this project, we will collect magnetic resonance imaging (MRI) data of AD, MCI and normal controls. From the view of brain regional connectivity and whole network, we will explore changes of brain connectivity in early AD and MCI. Firstly, we will divide the cognitive-related regions including hippocampus, precuneus and inferior parietal lobule as different subregions. Then we will employ resting functional MRI analysis to study the functional connectivities changes of the different brain subregions of early AD and MCI. Then, we will trace the fiber bundle by diffusion tensor imaging (DTI) method and investigate the structural connectivities among the above brain subregions. At same time, we plan to construct the whole brain complex network from the overall angle and analyze the abnormal network characteristics of AD and MCI. At last, we will analyze all kinds of imaging biomarkers representing regional brain connectivity and whole brain complex network characteristics. Based on the analysis of the relationship between the imaging biomarkers and the neuro-phsychological examination scores, we will screen the sensitive imaging biomarker of AD and MCI. By combination analysis of regional and whole network, this study aims to reveal the pathophysiology of early AD and establish the imaging evaluation standard for early AD diagnosis.

阿尔茨海默病（AD）是严重威胁人类健康的脑重大疾病，轻度认知功能障碍(MCI)是AD的早期阶段，失连接综合症是AD发病机制中的重要假说，本课题收集AD、MCI和正常人的磁共振数据，从脑局部连接和整体网络两方面进行早期AD和MCI脑连接性研究，首先我们将认知相关脑区包括海马、楔前叶及顶下小叶分割为不同亚区，利用静息态脑功能成像方法分析早期AD和MCI各亚区的功能连接改变，采用扩散张量成像对纤维束进行追踪，探索亚区的结构连接改变，同时课题组拟从整体角度构建全脑复杂网络，分析AD和MCI的异常网络属性，最后综合分析反映局部脑区连接与整体网络属性的各项影像学指标，并与神经心理量表进行相关分析，筛选敏感指标。本课题通过局部与整体网络的综合分析，旨在阐明早期AD 的病理生理机制，建立AD早期诊断的影像学评价标准。

阿尔茨海默病（AD）是严重威胁人类健康的脑重大疾病，轻度认知功能障碍(MCI)是AD的 早期阶段，失连接综合症是AD发病机制中的重要假说，本课题收集AD、MCI和正常人的磁共振数据，从脑局部连接和整体网络两方面进行早期AD和MCI脑连接性研究，首先我们将认知相关脑区包括内顶区域、楔前叶及顶下小叶、杏仁核等分割为不同亚区，利用静息态脑功能成像方法分析早期AD和MCI各亚区的功能连接改变，同时采用脑功能成像和扩散张量成像对AD、MCI的大脑半球间连接进行评估，探索半球间的功能和结构连接改变，另外课题组从整体角度构建全脑复杂网络，分析AD和MCI的异常网络属性，最后综合分析反映局部脑区连接与整体网络属性的各项影像学指标，并与神经心理量表进行相关分析，筛选敏感指标。本课题通过局部与整体网络的综合分析，阐明了早期AD 的功能失连接的病理生理机制，为建立AD早期诊断的影像学评价标准提供了理论依据。