Longitudinal progression of grey matter atrophy morphological characteristics in MCI patients

Objective To investigate the differences of cerebral grey matter atrophy over time between MCI (Mild Cognitive Impairment) and NC (Normal Control), and further investigate the differences of cerebral grey matter atrophy between SMCI (Stable MCI) and PMCI (Progressive MCI). Methods Based on improved VBM-DARTEL method, NC and MCI longitudinal datasets of 3 years were processed. Firstly, the atrophy patterns and atrophy rates of NC and MCI were obtained. Then, the differences of atrophy within some certain cerebral regions between SMCI and PMCI were explored applying the ROI (Regions of Interest) method. Fractal dimensions were also applied to describe the texture features of the atrophy regions within ROIs and differences of atrophy rates were also calculated. Results With the time varying, the atrophy regions were gradually expanding. In MCI, the atrophy pace was faster and the atrophy rate at the same time point was higher than that in NC. By longitudinal comparison between SMCI and PMCI, it was found that the atrophy in PMCI appeared earlier in the hippocampus, the temporal lobe, the cingulate gyrus and the caudate nucleus and showed an increasing atrophy rate and decreasing fractal dimensions. Conclusions VBM-DARTEL method can be applied to study the cerebral grey matter atrophy effectively. The results showed that the cerebral grey matter changing over time was more obvious in MCI, which can be used to diagnose early AD. Compared to SMCI, there appeared more obvious atrophy in some certain regions of cerebral grey matter in PMCI. So these atrophy differences between SMCI and PMCI can be the evidence to identify PMCI and was of help for clinical diagnosis, clinical intervention and clinical treatment of early AD.