Which findings on ultrasound are indicative of portal hypertension?

The presence of dilated portal vein, ascites, and collateral circulation on ultrasound is indicative of portal hypertension. Portal hypertension occurs when there is increased pressure in the portal venous system, often due to conditions such as cirrhosis or hepatic venous outflow obstruction.

A dilated portal vein is a direct sign of increased pressure, as the vein cannot accommodate the usual blood flow due to the resistance within the liver. Ascites is commonly associated with portal hypertension as increased pressure can cause fluid leakage into the abdominal cavity. Additionally, collateral circulation develops as the body attempts to bypass the increased resistance through the portal vein, leading to the formation of new vascular pathways, which may be observed on ultrasound as enlarged veins, particularly in areas like the paraumbilical region (forming "caput medusae") or around the esophagus.

Other options do not specifically indicate portal hypertension. For instance, gallbladder enlargement and pancreatitis are associated with other gastrointestinal issues, and while gallstones can sometimes contribute to bile duct obstruction that affects portal pressure, they do not inherently signify portal hypertension. Likewise, thickened bowel walls and diverticulitis relate to bowel conditions rather than alterations in portal venous pressure.