Functional Liver Imaging Score (FLIS): A Prognostic Biomarker for Acute-on-Chronic Liver Failure and Liver-Related Mortality

Background/Aims The Functional Liver Imaging Score (FLIS; range 0–6, with higher scores indicating better liver function), derived from gadoxetic acid-enhanced MRI, is a prognostic imaging biomarker in advanced chronic liver disease (ACLD). Our aim was to investigate whether semiquantitative FLIS and quantitative imaging parameters, namely relative liver enhancement (RLE), relative enhancement ratio of the biliary system (REB), and liver-to-portal vein contrast ratio (LPC), predict acute-on-chronic liver failure (ACLF; a syndrome defined by extrahepatic organ failure and high short-term mortality)/liver-related mortality in acute decompensation (AD), the main at-risk population. Methods We included 210 patients with ACLD with GA-MRI-derived, semi-quantitative FLIS, in whom the RLE, REB, and LPC were also computed by two independent, experienced radiologists. Patients were stratified into clinically stable ACLD (including compensated or non-acutely decompensated) and AD. The prognostic value of semi-quantitative FLIS and quantitative GA-MRI parameters for ACLF/liver-related death was evaluated using competing risk regression analyses, considering liver transplantation as a competing event. Results The FLIS was lower in AD (vs. clinically stable ACLD). Furthermore, low FLIS was an independent risk factor for ACLF development/liver-related death in AD (adjusted subdistribution hazard ratio [aSHR]: 2.37 [95%CI: 1.08-5.17], p=0.031; accounting for MELD-Na, albumin, and aetiological cure), but not in clinically stable ACLD (aSHR: 1.58 [95%CI: 0.73-3.45], p=0.250). Conversely, while RLE, REB, and LPC could distinguish between AD and clinically stable ACLD (p<0.001), they failed to predict ACLF/liver-related death. Conclusions The Functional Liver Imaging Score (FLIS) is a simple prognostic imaging biomarker in acute decompensation that predicts acute-on-chronic liver failure and liver-related mortality. FLIS-based risk stratification may help identify patients who could benefit from intensified monitoring or timely liver transplant evaluation. Impact and Implications The visual, semi-quantitative Functional Liver Imaging Score (FLIS), derived from gadoxetic acid-enhanced MRI, assesses liver function. We found that FLIS predicts acute-on-chronic liver failure/liver-related mortality in patients with acutely decompensated cirrhosis, independent of established risk scores. Conversely, quantitative MRI parameters did not add prognostic value.