关键词: 磁共振成像； 弥散张量成像； 轻度认知功能障碍；海马

Abstract:

Objective   To investigate the difference of average diffusion coefficient (ADC) 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. Methods   We selected a total of 18 MCI patients (MCI Group) and 18 individuals with normal cognition (NC Group), the two groups being matched by gender, age and education. A comparison was done for the two groups in ADC and FA in the HP. A possible correlation between the ADC and FA values of the MCI patients and their Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Activities of Daily Living (ADL) scores was examined. Results   Compared with the NC Group, the MCI Group exhibited significantly high ADC for the left HP and the total bilateral HP（P＜0.01）, whereas the two groups were not significantly different in the right HP（P＞0.05）. With FA，the two groups were not significantly different in the left, right and total bilateral HP (P＞0.05). The MCI Group had lower MMSE and MoCA scores, but higher ADL scores than the NC Group　(P＜0.01). In addition, MMSE showed a negative correlation with ADC of the left HP and total bilateral HP (P<0.01), but had no significant correlation with either FA or ADC of the right HP (P＞0.05) . Furthermore, MoCA and ADL did not have significant correlation with either ADC or FA (P＞0.05). Conclusion   MR-DTI is a helpful tool in MCI diagnosis．

Key words: Magnetic resonance imaging; Diffusion tensor imaging; Mild cognitive impairment; Hippocampus