대뇌 피질 모델링 기술을 이용한 알츠하이머 환자의 대뇌 회백질영역의 평균확산도에 관한 연구

Abstract

The recent studies have been used mean diffusivity of cortical gray matter (GM) for detecting specific diseases characteristics. However, as contrasted with a lot of utilization of mean diffusivities for detect local abnormalities in white matter(WM) and deep GM, the cortical GM has not been concerned in diffusion tensor imaging (DTI) study. Especially, the Alzheimer’s disease (AD) is generally viewed as a GM disease. Pathologic changes in the cortical gray matter of the brain in AD are characterized by the accumulation of neurofibrillary tangles and senile plaques along with neuronal and synaptic loss that produce cerebral atrophy. In present study, we investigated changes in mean diffusivity (MD) values in cortical GM regions in AD patients compared with a healthy elderly group using surface-based mophometry. The group difference between healthy normal and AD patients was analyzed on cortical surface model. To improve coregistration performance between B0 volume from DTI and T1-weighted volume and correct partial volume effect (PVE) on cortical GM, coregistration was performed using Thin-Plate Spline (TPS) non-linear warping and the PVE on cortical GM in MD map were minimized using PVE map from T1-weigheted volume. In our results, the MD of AD group showed significant increase in bilateral temporal lobe in lobar analysis. Also, the MD in AD group was significantly elevated when compared to controls in bilateral regions: inferior temporal gyrus, inferior occipital gyrus, middle temporal gyrus, precuneus, cuneus and unilateral regions in right hemisphere with Lateral occipito-temporal gyrus, parahippocampal gyrus, precentral gyrus, supramaginal gyrus in left hemisphere with angular gyrus, lateral front-orbital gyrus. Higher MD value in AD can be explained by degeneration of gray matter structure. Although the precise neural correlates of elevated MD are unknown, the MD measures may be sensitive to AD neuropathology and, when used conjointly with structural MRI such as cortical thickness generated from cortical surface model, may provide an additional strategy for monitoring the progression of AD.