Fig. 1.
Illustration of combining functions (S1 and S2) that define critical regions of concordant changes between two DTI measures, such as fractional anistropy (FA) and mean diffusivity (MD) on a map of T-statistic values. (A) Simultaneous changes of DTI measures in the same directions (i.e. both measures increase or decrease); (B) Simultaneous changes of DTI measures in opposite direction (i.e. one measure increases whereas the other decreases).