The etiology of portal venous thrombosis is varied. Extrinsic compression of the vessel by a mass, infection, trauma, pancreatitis, hepatic venous obstruction and hypercoagulable states are common causes. This patient had a history of pulmonary embolism and is being worked up for hypercoagulable states.

Thrombosis may be acute or chronic in nature and is sometimes difficult to differentiate. Chronic thrombosis results in collateral vessels and these small vessels may be the only remaining vessels with the portal vein atrophied. The liver can be affected with differential attenuation which is not seen on these images.

Acute mesenteric venous thrombosis cause congestion, edema, and hemorrhage and necrosis. Symptoms are usually gradual and over 1 week period. 10% of intestinal ischemia is caused by mesenteric venous thrombosis. Causes are similar to portal vein thrombosis.

Anticoagulation is the therapy of choice.