This document provides an overview of Doppler ultrasound in evaluating portal vein thrombosis. It discusses the etiology, sensitivity, indications, and appearance of complete and partial portal vein thrombosis. It also summarizes ultrasound findings in related conditions like mesenteric and splenic vein thrombosis. Chronic portal vein thrombosis and associated complications like portal cavernoma and portosystemic collaterals are also described. The role of contrast-enhanced ultrasound in diagnosing malignant portal vein thrombosis is mentioned.