Region-specific changes of cerebral white matter during normal aging: a diffusion-tensor analysis.

With aging, the human brain tissue undergoes degeneration and a decline in cognitive function. Diffusion tensor imaging (DTI) is a sensitive method for detecting microstructural changes of the brain white matter (WM). We examined the age-dependent, region-specific, changing patterns in microstructures of the brain. This was preformed by DTI analysis of 58 healthy volunteers from Korea. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured for each region of interest (ROI) in 22 areas. The FA and ADC values of all 22 ROIs were, respectively, compared among the age groups, by linear regression analysis and analysis of variance. With aging, the ADC values tended to increase and the FA values tended to decrease. Patterns of regional changes of the FA were divided into three subgroups. The cingulum was affected earliest with aging and the age-related WM changes show an anterior to posterior gradient acceleration throughout the decades tested. This study suggests that DTI is sensitive enough a diagnostic tool to detect subtle microstructural changes. These results show that the WM has a region-specific vulnerability to the aging process.