Age- and gender-related changes in the normal human brain using hybrid diffusion imaging (HYDI)

► In normal healthy brain, the q space diffusion measures including fast diffusivity and the volume of fast diffusion compartment and the axial diffusivity of DTI were most influenced by age. ► Measures of restricted, slow, and radial diffusion appear to be stable across this middle age range. ► An age-related decrease in FA was observed in prefrontal areas including the genu of the corpus callosum. ► Results suggest that myelination is generally stable in most of the white matter through much of healthy adulthood; however, the axonal properties may be affected.