Portal vein hemodynamics: MR imaging and MR angiography

Abstract

Magnetic resonance imaging (MRI) is a noninvasive imaging method that is useful for evaluating the state of portal hypertension and the portal collateral vessels. Liver and spleen stiffness can be assessed means of MR elastography, and their stiffness makes it possible to predict the occurrence of esophageal varices. Recently, non-contrast-enhanced MR angiography (NCE-MRA) has been applied to the abdominal region, and selective imaging of the hepatic artery, hepatic vein, or portal vein has become possible in the liver. NCE-MRA enables us to understand the blood flow of the portal collateral circulation. Furthermore, multiple shunts can be detected at the same time. NCE-MRA is a potentially useful method for screening in patients with portal hypertension due to its invasiveness. In contrast-enhanced 3D-CT, as both the arteries and veins are displayed, it takes time differentiating arteries from veins. In contrast, selective vessel imaging is possible with NCE-MRA. Thus, acquiring a 3D image is easier with NCE-MRA than with CT.