[Multi-modality magnetic resonance imaging features of cognitive function in mild cognitive impairment]

To investigate the association of multi-modality neuroimaging features and cognitive function in mild cognitive impairment (MCI) and Alzheimer's disease (AD).

Nine individuals with amnestic MCI (aMCI), fifteen patients with mild probable AD, and eleven age-controlled cognitively normal controls (NC) were recruited. All participants were administered with mini-mental status examination (MMSE) and Cognitive assessment screening instrument (CASI) to assess general cognitive function. Optimized voxel-based morphometry (VBM) was used for the analysis with 3-D high resolution anatomical images. Values of fractional anisotropy (FA) and mean apparent diffusivity coefficient (ADC) were measured from different brain regions on diffusion-tensor images (DTI). The relationship between structural atrophy and DTI-based measurements in the selected brain regions was examined.

The scores of MMSE and CASI were correlated with the volumetric changes in such areas as temporal, frontal and parietal lobes, and cingulate gyrus and hippocampal gyrus (P<0.001). The scores of MMSE and CASI were positively correlated with FA values, and negatively with ADC values in the white-matter-affected regions including temporal, frontal, parietal lobes, cingulate gyrus, and parahippocampal gyrus (P<0.05).

Cognitive decline was associated with atrophy and white matter microstructural alterations in temporal, frontal, parietal lobes, cingulate gyrus, and parahippocampal gyrus in MCI and AD. Multi-modality imaging technique may be important in elucidating the brain mechanism of cognitive impairment.