R₂-LIC calibration curve. Liver <R₂> measurement for the region bounded by the surface of the right lobe of the liver and a sagittal plane 35 mm medial to the most lateral surface point versus needle biopsy LIC. The solid line is the calibration determined by curve fitting to the data. The Pearson correlation coefficient of the calibration with the data is r = 0.98. The error bars indicate the estimated ± 19% uncertainties on biopsy measurement of average LICs. The uncertainty of 19% is based on studies of LIC heterogeneity in fibrosis-free liver.^7,8  The dashed lines indicate the 95% limits of agreement between R₂-LIC and biopsy LIC. Subject groups are hepatitis (○), HH (▪), β-thalassemia/hemoglobin E (•), and β-thalassemia ().