Clinical Study Of Diffusion Tensor Imaging In Mild Cognitive Impairment

Objective:To explore the characteristic values in Diffusion tensor imaging(DTI): the role of changes of fractional anisotropy(FA)and apparent diffusion coefficient(ADC)in Mild cognitive impairment(MCI)diagnosis.Materials and methods:Thirty patients with MCI diagnosed clinically and 20 patients as normal control group were enrolled in this study.The diagnosis of MCI uses the criteria set by Petersen et al.Normal control group(NC)were enrolled in healthy subjects,The patients were matched for age,gender and education level.All patients had no serious cognitive impairment,no major disease history,no history of mental illness and dementia family history.Neuropsychological tests were performed using the mini-mental state examination scale(MMSE)(NC ? 27;MCI 24-27),the Chinese version of the montreal cognitive assessment scale(MOCA)(NC ? 24 points;MCI 15-24).Two groups of subjects were examined by Semens 3.0T MRI diffusion tensor imaging technology.The original image is processed by post-processing software in the workstation and measured by the same technician.We measured the same size and the same area of interest in the bilateral cerebral hemispheres for each image.These regions of interest include bilateral hippocampus,bilateral temporal lobe,bilateral frontal lobe,bilateral genu corporis callosi,bilateral corporis callosi splenium,bilateral posterior of cingulate gyrus.The FA and ADC at these regions were measured separately and recorded.The differences of ADC and FA between the two groups were compared respectively.And the correlation between FA and the scores of MOCA in the lesions of MCI patients was analyzed.We use the social science statistical software SPSS statistical software 19.0 for statistical analysis.And there were P <0.05 when the difference was statistically significant.Results:1.There was no significant difference in gender,age and educational level between MCI groups and NC groups(P> 0.05).2.The FA of left hippocampus and genu corporis callosi in MCI groups were significantly lower than that in NC group(P <0.01).The FA of bilateral posterior cingulate gyrus in MCI groups were significantly lower than that in NC group(P <0.05).3.There was no significant difference in FA between the right hippocampus,tubera corporis callosi,bilateral temporal lobe and bilateral frontal lobe of MCI group and NC group(P> 0.05).4.The ADC of left hippocampus in MCI groups were significant higher than that in NC groups(P <0.01).There were no significant difference in ADC of right hippocampus,bilateral temporal lobe,bilateral frontal lobe,genu corporis callosi,tubera corporis callosi and bilateral cingulate gyrus in MCI groups compared with NC groups(P> 0.05).5.FA in the lesion site of MCI groups was positively correlated with calculating power,delayed recall,and abstract thinking in the sub-item of MOCA scale.Conclusion:1.Some white matter fiber tracts in patients of MCI groups were absent in different degrees.The results suggest that the FA of left hippocampus,genu corporis callosi,bilateral cingulate were decreased.2.FA in the lesion site of MCI groups was positively correlated with calculating power,delayed recall,and abstract thinking in the sub-item of MOCA scale.To a certain extent,the size of FA can indicate the level of cognitive function.