MRI观察阿尔茨海默病患者大脑静息网络改变

目的 观察AD患者与正常对照组脑静息网络的差异.方法 分别对根据临床诊断的19例AD患者及20例年龄匹配的对照者进行静息功能磁共振扫描及三维MPRAGE-T1权重像扫描.所得数据用SPM2进行预处理,随后用GIFT 1.3b独立成分分析方法表示两组脑激活区.结果 在AD患者及对照组中均发现了与以往文献相同的6个静息网络,其中在第一个网络即默认网络和第二个网络即背侧注意网络中两组差异存在显著统计学意义.在默认网络中,对照组比AD组激活多的脑区包括双侧小脑半球、颞上回、颞中回、额下回,左侧额上回、额中回,右侧眶回;AD组比对照组多激活的脑区包括双侧额中回、顶下小叶及右侧楔前叶/扣带回后部.在背侧注意网络中,对照组比AD组多激活的脑区包括双侧小脑半球、额中回,左侧枕中回、额上回;AD组无明显强于对照组脑激活区.结论 阿尔茨海默病与对照组脑静息网络存在显著差异,为临床早期诊断老年痴呆提供了可能的影像学途径.

MRI observation of changes of brain resting-state networks in patients with Alzheimer disease

Objective To evaluate the difference of brain resting-state networks (RSNs) between Alzheimer disease (AD) patients and controls. Methods Nineteen patients with AD and 20 controls were recruited in the study. Resting-state fMRI data and MPRAGE structure images were obtained using Simens Trio 3.0 Tesla MR scanner. Then the data were analyzed by SPM2 and GIFT 1.3b. Cerebra functional connectivity was revealed by independent component analysis (ICA) and compared between the two groups with SPM2. Results Six RSNs were revealed in both AD and control group, in accordance with previous studies. Decreased functional connectivity was detected only in default mode networks (DMNs) and dorsal attention networks (DANs). Furthermore, in patients with AD, decreased activity in DMNs was demonstrated in bilateral cerebrum, superior temporal gyrus, middle temporal gyrus, inferior frontal gyrus and left superior frontal gyrus and right orbital gyrus. Increased activity in DMNs was demonstrated in bilateral medial frontal gyrus, inferior parietal lobule and right precuneus. On the other hand, decreased activity was also revealed in parts of the dorsal attention area, including bilateral cerebrum, medial frontal gyrus, left superior frontal gyrus and middle occipital gyrus. Conclusion Significant deviation exists in RSNs deviation between AD and controls, providing a possible image methods to early diagnosis of AD.