Inferior right hepatic veins: MR assessment of prevalence and potential clinical significance in children.

The prevalence of Inferior Right Hepatic Veins (IRHVs) in 82 children who had magnetic resonance imaging (MRI) of the abdomen was assessed. IRHVs larger than or equal in size to the Superior Right Hepatic Vein were found in 23% (19/82). In two patients with radiological evidence of Superior Hepatic Venous occlusion and without radiological evidence of portal hypertension, venous drainage was accomplished via large IRHVs. The findings suggest that, in children, IRHVs may act as efficient collaterals and help protect the liver from the consequences of high IVC obstruction.