Study On Brain’s Structure And Function Of Chronic Mountain Sickness With3T DTI And BOLD Magnetic Resonance Imaging

Objective: Using3.0T ultra-high field strength resting blood-oxygen level dependentfunctional magnetic resonance imaging (BOLD-fMRI) and diffusion tensorimaging (DTI) technology, we explored the spontaneous brain activity and whitematter structure characteristics in patients with chronic mountain sickness (CMS).The purpose was to investigate the effects of chronic hypoxia on brain structure andfunction.Methods: Thirteen diagnosed with CMS patients and twelve gender, age, educationlevel and altitude matched healthy controls were performed resting-state BOLD andDTI magnetic resonance scans. Regional homogeneity (ReHo) method was appliedto process the BOLD data, to analysis the features of spontaneous brain activity inCMS group and control group during the resting state. We use the tract-based spatialstatistics (TBSS) analysis the DTI data, and calculate the CMS group and thecontrol group‘s anisotropic parameters (fractional anisotropy (FA), mean diffusivity(MD), axial diffusivity (AD) and radial diffusivity (RD)). For the BOLD data weadopted the method by which was based on voxel single-sample t-test within thegroup and comparison between the two groups by voxel–based two-sample t-test.DTI data between the two groups were compared using voxel-based two-samplet-test.Results:1.The results of ReHo analysis:①under resting state, control and CMSgroups were activated in multiple brain regions, but compared with control group,the extent of the consistence of the CMS group partial neuronal activity is relativelylow.②Comparedwith the control group, ReHo in the CMS group increased in theleft parahippocampal gyrus, and left postcentral gyrus; decreased in bilateral inferiortemporal gyrus, right fusiform gyrus and the left middle frontal, the difference wasstatistically significant (p<0.01, alphasim correction).2. The results of DTI analysis:①Compared with control group, CMS group in thecerebellum showed a lower MD, in the cerebellum and the splenium of thesplenium of corpus callosum showed a lower AD;②Compared with the controlgroup, CMS group not showed significantly increased FA, MD, AD and RD inany brain region (P <0.01, uncorrected).Conclusion: There are significant differences in ReHo between CMS group and thecontrol group. Additionally, the differences of anisotropy parameters of the whitematter also exist between the two groups. These differences in structure andfunction can help us to deeply understand the effects of chronic hypoxia on the brain.