阿尔茨海默病患者大脑功能网络的改变

The Functional Brain Network Changes of Alzheimer's Disease

目的:本文的研究目的在于利用AD(Alzheimer's Disease)患者和健康对照组的静息态功能磁共振数据,结合复杂网络的理论去研究AD患者大脑功能网络拓扑参数的改变。方法:本研究收集10例AD患者和11例健康对照组的静息态功能磁共振数据,对采集到的数据首先进行预处理。按照AAL模板把每个被试的大脑分割为90个脑区,提取出每个脑区的时间序列。利用Pearson相关建立时间序列之间的相关关系,选取一个较宽泛的阈值范围把每个被试的邻接矩阵变为二值矩阵。然后计算每个被试网络的拓扑参数,并在组间进行平均。结果:研究结果表明与健康对照组相比,AD患者组的平均最短路径变长,相配系数变大,同步性变弱。结论:这样的结果为AD患者的研究提供新的视角,并可能成为AD早期诊断的生物学标识。

Objective： The purpose of this study is to explore the change of topology parameters of AD （Alzheimer＇s Disease） patients used by the resting-state fMRI （Functional magnetic resonance images） and the theory of complex network. Methods： 10 AD patients and 11 healthy controls of resting-state fMRI datasets were collected during this study. Firstly, all of the datasets were preprocessing. Then, combined with Automated Anatomical Labeling （AAL）, time series of 90 brain regions from each subject were extracted. We used Pearson correlation method to calculate the correlation coefficient between the time series, and an adjacency matrix with 90＊90 was obtained fi＇om the correlation coefficient. A wide threshold range was used to transform the adjacency matrix to a binary matrix. At last, the topology parameters of each network were calculated, and all of them were then averaged within a group. Results： The results illustrated that compared with the topology parameters of the fimctional brain network of healthy controls, the average shortest path length of the AD patients was longer, the assortativity coefficient was bigger and the synchronous was weakened. Conclusions： These results provide new perspective for the study of patients with AD, and may be the biological identity of the AD early diagnosis.