Comprehensive Evaluation of Fontan-Associated Liver Disease: The Role of Magnetic Resonance Imaging

Background: Fontan-associated liver disease (FALD) develops as a consequence of chronic systemic venous congestion, which alters hepatic hemodynamics and promotes sinusoidal congestion, inflammation, and fibrosis. Our objective was to evaluate liver changes using magnetic resonance imaging (MRI) in patients with a Fontan circuit. Methods: We conducted a retrospective study including patients who underwent the Fontan procedure between January 2005 and December 2019 and were evaluated using T1, T2 and apparent diffusion coefficient mapping. Patients were classified into two groups: none-to-mild FALD (≤5 points) and moderate-to-severe FALD (≥6 points). FALD severity was characterized, and logistic regression analysis was performed to evaluate the association between the variables of interest and the outcome. The discriminative performance of quantitative MRI parameters was also assessed using ROC curves. Results: Thirty-nine patients were included, with a median age at surgery of 9.3 years (IQR 5.9–10.8); 61.5% (n = 24) were female. The most frequent diagnosis was tricuspid atresia (51.3%, n = 20), and the Fontan procedures were mainly performed using an extracardiac conduit (97.4%, n = 38). No factors were significantly associated with moderate-to-severe FALD. T1 mapping of segment I demonstrated the highest discriminative performance (AUC = 0.771; 95% CI: 0.500–1.000), with a cutoff value of >734 ms, yielding a sensitivity of 83.3% (95% CI: 43.65–99.15) and a specificity of 75% (95% CI: 57.89–86.75). Conclusions: After 10 years of follow-up, 15% had moderate-to-severe FALD. T1 mapping of segment I demonstrated the highest discriminative performance, with a sensitivity greater than 80% for identifying moderate-to-severe FALD.