The portacaval space: CT with MR correlation.

Between the portal vein and the inferior vena cava lies a small space that may be occupied by multiple anatomic structures including the caudate and papillary processes of the caudate lobe of the liver, portacaval lymph nodes, replaced or accessory right hepatic arteries, posterosuperior pancreaticoduodenal vessels, the cystic duct, and the epiploic foramen to the lesser sac. The sectional anatomy of these structures is illustrated in this paper with particular emphasis on the portacaval nodes. Unlike the adjacent celiac lymph nodes, portacaval nodes appear rectangular or elliptical on transverse sections and may measure up to 1.3 cm in anteroposterior dimension. They may mimic portions of the pancreas, liver, or biliary tract on sectional images.