Membranous obstruction of the inferior vena cava: an ultrasound, computed tomography, and inferior vena cavogram image correlation.

The purpose of this paper is to present the computed tomography (CT) and ultrasound findings in one case of membranous obstruction of the inferior vena cava (IVC). Although the incidence of membranous obstruction of the IVC is rare in the United States, the diagnosis is essential because of the association of this lesion with portal fibrosis and hepatocellular carcinoma. Membranous obstruction of the IVC is suggested by the findings of a filling defect within the IVC at the level of either the diaphragm or right atrium. Until more specific CT and ultrasound features are described, an inferior vena cavogram will remain the definitive diagnostic procedure for membranous obstruction of the IVC.