Objective To explore the differences between patients withchronic mountain sickness (CMS) and healthy people in the microstructure of brain gray and white matter by using diffusion kurtosis imaging (DKI). Methods 21 CMS patients were recruited to a study group and 20 healthy volunteers were assigned to a control group. Both groups received conventional MRI and DKI sequence scans. The mean kurtosis (MK) values ,radial kurtosis (RK) values and kurtosis anisotropy (KA) values in each region of interest (ROI) in the cerebral gray and white matter were measured and the same part of the left and right side ROI parameters was counted. The data satisfied the normal distribution and the paired samples t?test was used;the ROI parameters between the two groups in the same parts of the same side followed the normal distribution and the two independent samples t?test was used. Results The KA values in both sides of the anterior limb of internal capsule ,the MK values and RK values in bilateral caudate nucleus head and thalamus had side difference in CMS group. In both sides of the anterior limb of the internal capsule′s MK values,KA values and thalamus′s MK values,RK values existed side difference in the control group. The KA values of the right anterior limb in internal capsule were lower than those in the left in both groups;the right thalamus′s MK values and RK values were higher than the other side. The RK value in genu of corpus callosum differed significantly ,and it was lower the CMS group than in the control group. The difference of the KA values in corpus callosum ,the MK value in the left anterior limb of internal capsule ,the RK values in the left posterior limb of internal capsule ,the MK values in the right caudate nucleus head ,the MK values in bilateral lenticular nucleus and the MK values and KA values in the right thalamus were significant ,and they were higher inthe CMS group than in the control group. Conclusions The left and right cerebral hemispheric micro?structure is not exactly symmetrical between patients with CMS and healthy people living in high altitude areas , there are differences in some brain areas. The sensitivity and reactivity of brain tissue to high altitude hypoxia are different in patients with CMS ,there are various degrees of difference between the CMS and the normal in the corpus callosum,basal ganglia region and thalamus.

Objective To explore the gray and white matter microstructures in the brain of patients with different degrees of chronic mountain sickness(CMS).Methods 30 cases of CMS (10 cases in each group divided into mild,moderate and severe groups according to the severity)were collected as experimental group,and 10 normal adults in high altitude area were collected as the normal control group.All cases underwent MRI conventional head sequences,diffusion weighted imaging (DWI)and diffusion kurtosis imaging (DKI)sequences.The values of mean kurtosis(MK),radial kurtosis(RK),kurtosis anisotropy(KA)and apparent diffusion coefficient(ADC) graphs were reconstructed by post-processing software respectively.Selected the region of interest(ROI)symmetrically and fixedly, then measured and analyzed the parameter values of ROI in the same area.Results Compared the CMS groups with normal control group,the diffusion parameters and ADC values in certain parts of deep gray matter nucleus and white matter fibers were statistically significant,and the difference was significant with the progression of the disease.Conclusion DKI combined with DWI has certain value in evaluating the gray and white matter microstructure of human brain,there are some difference in the brain microstructure between CMS patients and high altitude normal subjects,additionally,the difference in different degrees of CMS is diverse.