Liver Transplantation Impaired Biliary Excretion of Gadoxate Is Associated With an Inferior 1-Year Retransplantation-Free Survival

Objectives: The aim of this study was to evaluate gadoxate-enhanced magnetic resonance imaging (MRI) in liver transplant recipients with regard to graft function and mortality at 1 year from imaging. Material and Methods: This was a retrospective, proof-of-concept study of gadoxate-enhanced 3-T MRI in 51 patients with orthotopic liver transplantation. Relative liver enhancement was calculated as the ratio between the signal intensities in unenhanced and gadoxate-enhanced T1-weighted gradient echo sequences with fat saturation. Impaired excretion was defined as the absence of gadoxate visualization in the common bile duct 20 minutes after intravenous injection. Results: Of the 51 liver transplant recipients, 31 patients showed a normal hepatobiliary excretion of gadoxate after 20 minutes (group A), whereas 20 patients showed an impaired excretion (group B). Group B had significantly higher serum levels of bilirubin (P < 0.001), aspartate-aminotransferase (P = 0.003), and alkaline phosphatase (P = 0.007), and a higher median Model for End-Stage Liver Disease score (P < 0.001). Within one-year of MRI, 55% of group B died (n = 7) or had to undergo retransplantation (n = 4), whereas all patients in group A survived without retransplantation (P < 0.001). The relative liver enhancement 20 minutes after gadoxate injection was directly related to serum levels of cholinesterase (P < 0.001) and inversely related to the serum levels of bilirubin (P = 0.0098), aspartate-aminotransferase (P = 0.007), and the Model for End-Stage Liver Disease score (P < 0.001). The relative liver enhancement 20 minutes after contrast injection was directly related to the probability of 1-year retransplantation-free survival in proportional hazard regression analysis (P = 0.005). Conclusion: Gadoxate-enhanced MRI may be a helpful noninvasive prognostic biomarker for chronic rejection and increased risk for 1-year mortality or retransplantation.