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.