Magnetic resonance venography in potential pediatric liver transplant recipients

Vascular anomalies may be hazardous to liver transplantation, and pre-operative vascular evaluation is important for a safe and successful operation. The purpose of this study was to assess the utility and accuracy of time-of-flight (TOF) magnetic resonance venography (MRV) with three-dimensional (3D) reconstruction as an alternative for conventional catheter angiography in evaluating the portal venous system and inferior vena cava (IVC) in potential pediatric liver transplant recipients. Twenty consecutive cases of small children with biliary atresia were evaluated with TOF MRV with 3D reconstruction by Advantage Window workstation. All 20 cases underwent conventional angiography; two cases received transhepatic portography and three cases received splenoportographic study. The whole MRV examination and filming required less than 30 min. Findings of portal vein and IVC completely agreed with or were superior to the successful catheter angiographic images. The portal vein was occluded in five cases, and patent in fifteen cases which included: twelve hepatopetal flow, two hepatofugal flow and one small caliber portal vein. Varices were found in 18 cases. In the case of the IVC, 18 of them were normal and 2 had congenital abnormalities which included paired vena cava and hypoplasia vena cava with compensatory enlargement of the azygos and hemiazygos systems. Eight of the cases received liver transplantation, and the MRV findings totally correlated with the final anatomy as found intraoperatively. MRV is accurate for evaluating the condition of the portal venous system and IVC, detection, and determining the distribution and extents of the varices. It is a reliable, noninvasive and rapid technique which can be considered as an alternative workup for the invasive angiography and or portography in small children for pre-transplantation evaluation.