Characterization of the evaluation method for hepatobiliary phase image by liver magnetic resonance imaging using Gd–EOB–DTPA

Purpose: This study aimed to characterize quantitative liver–spleen contrast (Q-LSC) and hepatocellular uptake index (HUI) for evaluating hepatobiliary phase (HBP) images using gadolinium–ethoxybenzyl–diethylenetriamine pentaacetic acid (Gd–EOB–DTPA) in liver magnetic resonance imaging and to identify differences in the results obtain from these two measurement methods. Methods: Twenty-nine consecutive randomly selected patients were assessed using the 3.0 T MR system. Three regions of interest (ROI) were set for the liver parenchyma and spleen, and signal intensity (SI) was averaged. Q-LSC (SI of the liver divided by the SI of the spleen) and HUI [(Q-LSC-1) × liver volume] were calculated. Moreover, the volume and mean SI of the whole liver and spleen, left lateral segment (LLS), and the other segments were calculated. Subsequently, ROI-based and volume-based values for Q-LSC (R-LSC and V-LSC) and HUI (R-HUI and V-HUI), and the whole and each segment were compared. Results: R-LSC and V-LSC for the whole and each segment were not significantly different. Conversely, all combinations of HUI, except between R-HUI and V-HUI were significantly different (P < 0.01), for the whole liver. Correlations between R-LSC, R-HUI, and volume-based LLS were lower than the others. Conclusion: Q-LSC and HUI were characterized through an imaging evaluation of HBP with Gd–EOB–DTPA. R-LSC and R-HUI, or V-HUI, of the whole liver were strongly correlated, but the LLS affected the data, and HUI depends on liver volume. R-LSC is simple and easy to use for HBP evaluation.