Figure 4.
Correlation plots of test-retest perfusion measurements in frontal and parietal regions of interest (ROI) in 13 volunteers, derived from spatially normalized perfusion-weighted imaging (PWI) data. Plots show that correlations between the test and retest examinations were slightly better in parietal than in frontal brain regions, regardless of the ASL method used. Perfusion was measured in arbitrary units (a.u.).