L. Ingram, Southampton, GB

Portal hypertension is defined as a pathological increase in portal venous pressure above 10mmHg due to increased resistance to portal blood flow. This can occur at the level of the portal vein (pre-sinusoidal), hepatic sinusoid or hepatovenous outflow tracts (post-sinusoidal). A consequence of persistent increased portal venous pressure is the formation of collateral pathways as blood circumvents the liver to pass through lower resistance porto-systemic channels. We aim to describe the sonographic and cross-sectional imaging features of portal hypertension.

Imaging findings OR Procedure findings

Sonographic features of portal hypertension can include a dilated portal vein, biphasic or reversed portal flow, splenomegaly, ascites as well as porto–systemic collateral pathways. Less commonly, a recanalised umbilical vein is identified sonographically. Collateral vessels are numerous and more readily identified on cross-sectional imaging. Common sites of collateralisation such as gastric, paraoesophageal, perisplenic and anorectal vessels are described as well as less common collaterals such as splenorenal and gastrorenal shunting, paravertebral, pericardiphrenic and retroperitoneal pathways. Uncommon collateral pathways have been linked to an increased Child-Pugh score. Sonography and cross-sectional imaging can also identify possible causes of portal hypertension including cirrhosis, portal vein thrombosis and Budd-Chiari syndrome.

Conclusion

Portal hypertension is a commonly encountered clinical condition and awareness of its radiological appearance such as collateral pathways can aid initiation of treatment and reduce the development of potentially devastating consequences such as variceal bleeding, portal colopathy and hepatic encephalopathy.

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