Changes of axial and radial diffusivities in cerebral white matter led by normal aging

PurposePurpose of the study is to reveal the changes of directional diffusion in cerebral white matter (WM) by normal aging.Materials and methodsThirty-nine volunteers were recruited to examine the changes in the directional diffusion of cerebral white matter (WM) due to normal aging.ResultsNo significant difference between the older and younger group (P > .05) was detected in the axial diffusivity (λll) of any of the regions of interest (ROI), while radial diffusivity (λ⊥) was significantly higher in the older group (P < .05) except for occipital lobe WM.Conclusionλll and λ⊥ may be used as in vivo markers that differentially and specifically reflect the WM changes of normal aging.