Fig. 2.

Group comparisons of volume and diffusion measures of a) WMC, b) parahippocampal WM and c) NAWM. The volume of WMC is normalized to the total WM volume. Parahippocampal and total WM volumes are normalized by the eTIV. Group differences were statistically assessed with the post-hoc Tukey test for each volume and diffusion measure, correcting for age, gender, education and motion measures (^*, ^** and ^*** for corrected p < 0.05, 0.01 and 0.001 respectively, ^† for uncorrected p < 0.05). The difference between diffusion properties of WMC and the corresponding diffusion properties in a non-lesioned normative brain is shown in addition to the absolute diffusion properties of WMC. The analyses involving diffusion measures in WMC were limited to individuals with a volume of WMC greater than 1% total WM volume. The log-transform of the normalized volume of WMC was used for statistical purposes. Standard error bars are shown. (MD, DA, and DR, mean, axial and radial diffusivity; FA, fractional anisotropy; WMC, white matter changes; WM, white matter; NAWM, normal-appearing white matter; eTIV, estimated total intracranial volume; CN, control; MCI, mild cognitive impairment; AD, Alzheimer’s disease).