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 semi-quantitative 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) and liver-related mortality in acute decompensation (AD), the main at-risk population.

METHODS

We included 210 patients with ACLD who underwent GA-MRI-derived semi-quantitative FLIS assessment, in whom 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 disease) 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, with liver transplantation considered a competing event.

RESULTS

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; adjusted for MELD-Na, albumin, and etiological 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 distinguished between AD and clinically stable ACLD (p <0.001), they did not predict ACLF/liver-related death.

CONCLUSIONS

The FLIS is a simple prognostic imaging biomarker in acute decompensation that predicts ACLF 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 and liver-related mortality in patients with acutely decompensated cirrhosis, independent of established risk scores. Conversely, quantitative MRI parameters did not add prognostic value. Thus, FLIS-based risk stratification may help identify patients who could benefit from intensified monitoring or timely liver transplant evaluation.