Clinical Study Of Magnetic Resonance Diffusion Kurtosis Imaging On The Microstructure Changes Of Medial Temporal Lobe In Patients With Mild Cognitive Impairment

Objective:To investigate the clinical value of diffusion kurtosis imaging（DKI）in the microstructure of medial temporal lobe in patients with mild cognitive impairment（MCI）.Methods:Forty-five patients with small cerebrovascular disease treated in the Department of Neurology from August 2020 to November 2021 were selected.The overall cognitive function of the patients was evaluated by Montreal cognitive assessment scale（Mo CA）.According to the existence of MCI,they were divided into MCI group（22 cases）and non MCI group（23 cases）.All patients underwent routine MRI morphology and DKI scanning.The medial temporal lobe of the patient was selected as the region of interest,including bilateral olfactory cortex,hippocampus and parahippocampal gyrus.The DKI related parameters of each region of interest were measured,mainly including axial diffusivity（Ad）,radical diffusivity（RD）,mean diffusivity（MD）,fractional anisotropy（FA）,kurtosis anisotropy（KFA）,mean kurtosis（MK）,axial diffusion kurtosis（AK）and radial diffusion kurtosis（RK）,the differences between the two groups were compared,and the comparison of DKI parameters on the left and right sides of each region of interest in MCI group,and the correlation between DKI parameters on the left and right sides of each ROI and Mo CA scale was analyzed.Results:（1）The Mo CA score of non MCI group was higher than that of MCI group,and the difference between the two groups was statistically significant（P<0.05）;There was no significant difference in gender,age,education time,Hamilton Depression Scale（HAMD）and Hamilton Anxiety Scale（HAMA）between the two groups（P<0.05）.（2）The Ad,MD and RD values of bilateral olfactory cortex,hippocampus and parahippocampal gyrus in MCI group were significantly higher than those in non MCI group（P<0.05）.The FA,AK,MK,RK and KFA values of bilateral olfactory cortex,hippocampus and parahippocampal gyrus in MCI group were significantly lower than those in non MCI group（P<0.05）.（3）The values of FA,MK,RK and KFA in the left hippocampus of patients in MCI group were significantly higher than those in the right（P<0.05）.The values of Ad,MD and RD in the left hippocampus of patients in MCI group were not significantly lower than those in the right（P>0.05）.The value of AK in the left hippocampus of patients in MCI group was not significantly higher than that in the right（P>0.05）.There was no significant difference in DKI parameters between left and right olfactory cortex and left and right parahippocampal gyrus in MCI group（P>0.05）.（4）The Ad,MD and RD values of bilateral olfactory cortex,hippocampus and parahippocampal gyrus in MCI group were negatively correlated with Mo CA score（P<0.05）,and FA,AK,MK,RK and KFA were positively correlated with Mo CA score（P<0.05）.Conclusion:The changes of DKI related parameters were correlated with the decline of cognitive function,DKI technique can be used as an effective method to observe the changes of medial temporal lobe microstructure in patients with mild cognitive impairment,and its related parameters have certain application value for the clinical imaging evaluation of patients with MCI.