Fig. 3

Statistical parametric mapping (SPM) analysis of subject group relative cerebral blood flow (rCBF). T-value maps, produced from two-sample t-tests using SPM12, were overlaid on a single-subject rCBF map. Shown are axial slices at the level of the circle of Willis and T-value maps comparing all subject groups across time points. Regional differences are shown for each group comparison, where higher T-values (warmer colors) indicate greater differences. Group 1 (improved cognition) and group 3 (worsened cognition) show the greatest differences in rCBF (uncorrected P<.01) particularly at the 4-week and 8-week time points in the bilateral middle cerebral arteries (arrows)