Magnetic resonance imaging evaluation of the effects of ageing on grey-white ratio in the human brain.

A previous neuropathological report noted a non-linear pattern of change in cerebral grey-white matter ratio during ageing. In that report, grey-white ratio decreased from age 20 to age 50, then increased in elderly subjects. The objective of the current study was to attempt to replicate this pattern of age-related change in the grey-white ratio in living human subjects using quantitative magnetic resonance imaging segmentation analysis. We measured the grey-white ratio in 78 subjects between the ages of 19 and 77 years, using a computer segmentation algorithm with magnetic resonance images. In agreement with the previous neuropathological report, the current in vivo magnetic resonance study found that the grey-white ratio declined from age 20 to age 50, then increased in elderly subjects