Figure 3.

(A) Correlation of median ${\text{T}}_2$ values from repeated measurements of ten subjects in four gray matter regions of interest (ROIs) at four postlabeling delays PLD = 0.9/1.2/1.5/1.8 s. The solid line is the identity function and represents optimal correlation. (B) Agreement (Bland–Altman plot) between test and retest ${\text{T}}_2$ values which are shown in (A). The mean differences between both scans at each PLD are represented by the dashed lines and dotted lines display the corresponding limits of agreement ($1.96\times$ standard deviations of mean differences).