Fig. 7

Comparison of chemical CIC measurements with T2*-based CIC estimates using 3 different calibration curves. a–c Display the relationship between CIC values, assessed chemically by use of post-mortem full-wall biopsies from cardiac septum (independent variable) and the corresponding CIC values predicted by the T2* method (dependent variable) using different calibration curves. In a, CIC values were predicted by the calibration curve obtained by use of EMBs for chemical assessment of CIC. In b, the predicted CIC values were calculated by use of the calibration curve from Carpenter et al. [12], based on a study on formalin-fixed hearts from TM patients with transfusion iron overload (TIO). In c, the calibration curve from Wood et al. [11] was used, based on dextran-iron loaded Mongolian gerbils. For details see the Results. Fat, dotted lines represent lines of equality. d–f display the agreement between CIC, assessed by use of post-mortem full-wall biopsies, and by CIC values predicted by use of the calibration curve coming from EMBs (d), from Carpenter et al. [12] (e) and from Wood et al. [11] (f). Agreement is assessed by Bland–Altman plots of the mean of 2 methods (x-axis), plotted against their difference (y-axis). The difference is given as absolute figures in mg Fe/g (d, f) and as percentages (g–i). The plots display the bias line (solid line), the 95% confidence lines around the bias, and the 95% confidence lines around the mean difference % (both are dotted lines). For details see the Results. Pred. CIC = predicted CIC. FWB = full-wall biopsies