Utility of fetal magnetic resonance imaging to assess fetuses with umbilical-portal-systemic venous shunt.

PURPOSE: The purpose of this study was to report our cases of umbilical-portal-systemic venous shunt (UPSVS) and to evaluate the utility of fetal magnetic resonance imaging (MRI) to diagnose this rare anomaly.

METHODS

This retrospective study included the fetuses with umbilical-portal venous system anomalies. All the cases were performed at 1.5 T magnetic resonance unit including the steady-state free precession (SSFP) and single-shot fast spin echo (SSFSE) sequences. We analyzed the abnormal anatomical findings by fetal MRI and compared them with the prenatal ultrasound (US).

RESULTS

15 cases with prenatally diagnosed UPSVS based on MRI or US were enrolled. Eight cases were identified by both MRI and US, including umbilical-systemic shunts (n = 3), ductus venosus-systemic shunt (n = 1), intrahepatic portal-systemic shunts (n = 3) and extrahepatic portal-systemic shunt (n = 1). Six cases were only identified by MRI including intrahepatic portal-systemic shunts (n = 5) and ductus venosus-systemic shunt (n = 1). In the remaining single case, prenatal ultrasound findings were suspicious for an intrahepatic portal-systemic shunt, without corresponding fetal MRI abnormalities. Follow-up data were obtained from thirteen patients. Two cases were lost to follow up. Of the thirteen patients undergoing follow-up, two cases of UPSVS were surgically confirmed. Postnatal imaging failed to identify any abnormalities of portal venous system in nine cases. The rest two cases demonstrated normal development and liver function after birth.

CONCLUSION

Umbilical-portal-systemic venous shunt can be diagnosed prenatally via MRI. Fetal MRI can serve as a valuable adjunct to prenatal US and improve the diagnostic accuracy.