Comparison of clinical MRI liver iron content measurements using signal intensity ratios, R(2) and R(2)*

PURPOSE: To compare three types of MRI liver iron content (LIC) measurement performed in daily clinical routine in a single center over a 6-year period. METHODS: Patients undergoing LIC MRI-scans (1.5T) at our center between January 1, 2008 and December 31, 2013 were retrospectively included. LIC was measured routinely with signal intensity ratio (SIR) and MR-relaxometry (R (2) and R (2)*) methods. Three observers placed regions-of-interest. The success rate was the number of correctly acquired scans over the total number of scans. Interobserver agreement was assessed with intraclass correlation coefficients (ICC) and Bland–Altman analysis, correlations between LIC(SIR), R (2), R (2)*, and serum values with Spearman’s rank correlation coefficient. Diagnostic accuracies of LIC(SIR), R (2) and serum transferrin, transferrin-saturation, and ferritin compared to increased R (2)* (≥44 Hz) as indicator of iron overload were assessed using ROC-analysis. RESULTS: LIC MRI-scans were performed in 114 subjects. SIR, R (2), and R (2)* data were successfully acquired in 102/114 (89%), 71/114 (62%), and 112/114 (98%) measurements, with the lowest success rate for R (2). The ICCs of SIR, R (2), and R (2)* did not differ at 0.998, 0.997, and 0.999. R (2) and serum ferritin had the highest diagnostic accuracies to detect elevated R (2)* as mark of iron overload. CONCLUSIONS: SIR and R (2)* are preferable over R (2) in terms of success rates. R (2)*’s shorter acquisition time and wide range of measurable LIC values favor R (2)* over SIR for MRI-based LIC measurement. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00261-016-0831-7) contains supplementary material, which is available to authorized users.