Fig. 4

Bland–Altman plots. Bland–Altman plots (a = reader 1 [R.H.]; b = reader 2 [K.F.v.D.]; c = reader 3 [E.E.D.]; d = reader 4 [M.M.]) showing the per-child differences between the first and second measurement of maximal synovial thickness on DIR MRI. On the x-axis, the average of maximal synovial thickness ((measurement DIR 1 + measurement DIR 2)/2) is displayed. The y-axis reflects the difference between both measurements (measurement DIR 1 − measurement DIR 2). Indicated by horizontal lines are the mean of the differences (bias) and limits of agreement (LOA; + 1.96 SD and − 1.96 SD). ICC, intraclass correlation coefficient (based on single-measurement, absolute-agreement, two-way mixed effects model); CI, confidence interval; *p value < .05