What portal diameter is suggestive of portal hypertension?

Portal hypertension is a condition characterized by increased blood pressure within the portal venous system, often due to liver cirrhosis or other obstructions. When assessing for portal hypertension using ultrasound, the diameter of the portal vein is a critical measurement to consider.

A portal vein diameter greater than 13 mm is typically indicative of portal hypertension. This cut-off is based on clinical studies and is used because, under normal circumstances, the portal vein diameter ranges from approximately 8 to 12 mm. When the pressure in the portal vein rises, due to conditions such as increased resistance in the liver or obstruction in the portal venous system, the vessel may dilate, leading to measurements exceeding the normal range.

In this context, a portal vein diameter of 13 mm aligns with the threshold that clinicians use to suggest the presence of portal hypertension. Measurements above this threshold warrant further investigation and evaluation of underlying causes, making it a key indicator in ultrasound assessments of patients who may exhibit symptoms of liver disease or portal hypertension.