The Value Of Magnetic Resonance Diffusion Tensor Imaging In Patients With Mild Cognitive Impairment

ObjectiveTo investigate the difference of average diffusion coefficient (DCavg) and fractional anisotropy (FA) in the hippocampus (HP) of aged groups that have mild cognitive impairment (MCI) and that have normal cognition, and to evaluate the applicability of magnetic resonance diffusion tensor imaging (MR-DTI) in MCI diagnosis.MethodsWe selected a total of24MCI patients and24individuals with normal cognition. The diagnosis of MCI was made by Petersen’s criteria. Normal control group were healthy volunteers or healthy physical examinees, being matched up by gender, age and education. They had no cognitive impairment, no severe internal diseases, no family history of dementia and mental problems. Neuropsychological scales tests, such as mini-mental state examination(MMSE), montreal cognitive assessment,(MoCA) and activities of daily living(ADL) were performed on all participants to confirm their cognitive status. All participants were scanned by using a single-shot, spin echo, echo planar imaging, diffusion-weighted sequence in addition to full conventional MRI, which included the T1WI axial, T2WI axial, T2fluid attenuated inversion recovery(T2FLAIR),T2WI sagittal. All the original images were processed by post-processing software in the workstation. A comparison was made for the two groups in DCavg and FA in the HP and a possible correlation between the DCavg and FA values of the MCI patients and their MMSE, MoCA, and ADL scores was examined. Statistical package for the social sciences for windows version13.0was used for statistical analysis, p-value less than0.05was considered statistically significant.Results1There were no significant differences with respect to age, gender and educational level between the two groups (P>0.05), but mean MMSE, MoCA and ADL scores differed significantly (P<0.05)2The MCI group exhibited significantly high DCavg for the left HP and the total bilateral HP (P<0.05), whereas the two groups were not significantly different in the right HP (P>0.05)3With FA, the two groups were not significantly different in the left, right and total bilateral HP (P>0.05).4MMSE showed a negative correlation with DCavg of the left HP and total bilateral HP (P<0.05), and had no significant correlation with either FA or DCavg of the right HP (P>0.05).5MoCA and ADL did not have significant correlation with either DCavg or FA (P>0.05).ConclusionThe HP is an important structure of medial temporal lobe and plays an important part in memory and cognition. Currently, researchs on the HP focuses on volume measurement and magnetic resonance spectroscopy. The related study on magnetic resonance diffusion tensor imaging is not too much yet. In the study, DCavg value of the left and bilateral HP of MCI group was significantly higher than that of the NC group; In addition, the DCavg value of the left HP and total bilateral HP showed a negative correlation with MMSE scores(P<0.05). Therefore, MR-DTI is helpful in the diagnosis of MCI.