Figure 1: Axial HASTE image demonstrates a soft tissue mass in the porta hepatis.

Figure 2: Axial VIBE post-contrast image demonstrates a soft tissue mass at the porta hepatis, with cavernous transformation of the portal vein.

Figure 3: Axial STIR image shows a soft tissue mass in the porta hepatis

Portal Cavernoma

Cavernous transformation of the portal vein, resulting in the so-called portal cavernoma, develops as a result of extrahepatic portal venous obstruction. The cavernoma is made up of multiple collaterals that develop in the porta hepatitis, bypassing the obstructed part of the portal vein. Magnetic resonance (MR) cholangiography has become the noninvasive procedure for the investigation of extra- and intrahepatic bile ducts.

A solid tumor-like cavernoma is defined as a uniform mass-like structure with a solid appearance mimicking a tumor (pseudotumor) in which the venous collaterals cannot be individualized. In patients with portal cavernoma, manifestations of biliary and cholangiographic abnormalities are present. Biliary stenoses and angulations are produced either by pressure from juxtaluminal collateral veins or encasement within a solid tumor-like cavernoma. Biliary complications are likely to become a prominent problem in patients with portal cavernoma. Secondary to improved control of thrombotic and bleeding complications and improved survival in patients with portal cavernoma, biliary changes develop progressively. MR imaging is an excellent procedure for diagnosing and elucidating the mechanism of biliary changes associated with portal cavernoma.

References:

1. Condat B, Vilgrain V, Asselah T, O'Toole D, et al . Portal Cavernoma-Associated Cholangiopathy: A Clinical and MR Cholangiography Coupled with MR Portography Imaging Study. American Journal of Roentgenology. 2005 Apr; 184(4): 1103-10.