The Fontan circulation and the liver: A magnetic resonance diffusion-weighted imaging study

Patients with a Fontan circulation tend to develop liver fibrosis, liver cirrhosis and even hepatocellular carcinoma. The aim of this study is to use the magnetic resonance technique diffusing-weighted imaging (DWI) for detecting liver fibrosis/cirrhosis in Fontan patients and to establish whether DWI results are associated with functional aspects of the Fontan circulation.

In a cross-sectional study, 59 Fontan patients were evaluated by liver DWI. The association between apparent diffusion coefficients (ADC) and patient characteristics, laboratory measurements and functional aspects of the Fontan circulation (NYHA class, maximum oxygen uptake during exercise and cardiac index) was assessed.

Liver ADC values were low (0.82×10(-3)±0.11×10(-3) mm2/s) compared with literature values for healthy volunteers and correlated negatively with calculated liver fibrosis/cirrhosis scores (Fib-4 score, p=0.019; AST/ALT ratio, p=0.009) and gamma-glutamyl transferase (p=0.001). Furthermore, ADC values correlated negatively with follow-up duration (p<0.001) and positively with cardiac index (p=0.019). No correlation between ADC values and exercise tests was found. In multivariable analysis, the ADC values were independently correlated with follow-up duration after Fontan completion.

The results of the current study suggest that progressive liver damage due to chronic congestion and potential hypoperfusion is reflected in the liver ADC values in Fontan patients. This study highlights that liver damage in the context of the Fontan circulation might be far more common than previously thought, and that the implementation of liver assessment in the routine follow-up of Fontan patients is recommendable.