Fig. 1.

Percent test-retest (PTRT, upper panel) and within-subject coefficient of variation (WSCV, lower panel) across the considered datasets. Each point in the plot, for a given dataset, represents a particular region of interest (ROI) so that the plot represents the variability of PTRT or WSCV across the considered ROIs. For each data set, DS1, DS2, DS3, DS4, and DS5, there were three quantification methods investigated (1, 2, and L denote one-tissue compartment model, two-tissue compartment model, and likelihood estimation in graphical analysis, respectively)