Magnetic Resonance Functional Brain Imaging Analysis of Physiology at Different Ages:A Small Sample Study Based on Whole-Brain Volume and Functional Networks
Magnetic Resonance Functional Brain Imaging Analysis of Physiology at Different Ages:A Small Sample Study Based on Whole-Brain Volume and Functional Networks
目的 探索生理性衰老受试者中大脑体积的变化以及全脑功能网络的特征性改变.方法 纳入正常中老年组志愿者组(50～80岁)42名(HC group 1,HCg1),中青年组(20～40岁)健康志愿者33名(HC group 2,HCg2).通过基于体素的形态学分析,对T1序列分割出的全脑皮质及白质体积进行组间比较.之后,对两组的静息态脑功能成像进行基于网络的分析,比较全脑功能网络与脑区的连接特征并对比功能连接均值.结果 在灰质体积分析中,HCg1较HCg2在双侧颞叶、额叶、小脑出现了显著的灰质体积减小(P＜0.05,FDR多重比较校正P＜0.01),白质体积的缩小发生在胼胝体体部及双侧穹窿脚.全脑网络连接均值比较中,HCg1表现出了更高的平均功能连接值(P＜0.05,FDR多重比较校正P＜0.01).结论 不同年龄段皮质及白质形态出现多个区域的萎缩,提示衰老过程伴随着多种局部基础生理机能的降低.但通过全脑功能网络的连接特征说明,大脑前部代偿性的功能连接增强,可能是脑功能的强健性及脑储备能力出现的原因之一.
Abstract
Objective To explore brain volume changes in physiologically aging subjects,as well as characteristic alter-ations in whole-brain functional networks.Methods In this study,there were 42 volunteers in the normal middle-aged and elderly group(50-80 years old)(HC group 1)and 33 healthy volunteers in the middle-aged and young group(20-40 years old)(HC group 2).We compared the whole brain cortical and white matter volumes segmented by T1 sequences be-tween groups by voxel-based morphological analysis.Afterwards,network-based analysis of resting-state fMRI was performed in both groups to compare the connectivity characteristics of whole-brain functional networks with brain regions and to com-pare the mean connectivity values.Results In cortical volume analysis,HCg1 showed significant cortical volume reduction in bilateral temporal lobe,frontal lobe,and cerebellum compared to HCg2(P＜0.05 FDR multiple comparisons corrected P＜0.01),and the reduction in white matter volume occurred in the corpus callosum and bilateral fornix.HCg1 exhibited higher mean functional connectivity values in the comparison of mean Whole-brain networks connectivity(P＜0.05 FDR multiple comparison corrected P＜0.01).Conclusion In the present study,we found multiple regions of atrophy in corti-cal and white matter morphology at different ages,suggesting that a reduction in multiple localised underlying physiological functions accompanies the aging process.However,the connectivity features through the whole brain functional network indi-cate that the enhanced functional connectivity due to compensation may be one of the reasons for the robustness of brain function and the emergence of brain reserve capacity.
维普
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