Risk Stratification of Patients with Marginal Hepatic Functional Reserve Using the Remnant Hepatocyte Uptake Index in Gadoxetic Acid-Enhanced Magnetic Resonance Imaging for Safe Liver Surgery

Background This study aimed to explore the efficacy of gadoxetic acid-enhanced (Gd-EOB) magnetic resonance imaging (MRI) in surgical risk estimation among patients with marginal hepatic function estimated by indocyanine green (ICG) clearance test. Methods This analysis focused on 120 patients with marginal hepatic functional reserve (ICG clearance rate of future liver remnant [ICG-Krem] < 0.10). Preoperative Gd-EOB MRI was retrospectively reviewed, and the remnant hepatocyte uptake index (rHUI) was calculated for quantitative measurement of liver function. The predictive power of rHUI for posthepatectomy liver failure was compared with several clinical measures used in current risk estimation before hepatectomy. Results Receiver operating curve analysis showed that rHUI had the best predictive power for posthepatectomy liver failure among the tested variables (ICG-R15, ICG-Krem, albumin + bilirubin score, and albumin + ICG-R15 score). Cross-validation showed that a threshold of 925 could be the best cut-off value for estimating the postoperative risk of liver failure with sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 0.689, 0.884, 5.94, and 0.352, respectively. Conclusion rHUI could be a sensitive substitute measure for posthepatectomy liver failure risk estimation among patients with marginal hepatic functional reserve.