Diagnosis of Portal Vein Thrombosis Clinical evaluation and liver tests Doppler ultrasonography Portal vein thrombosis is suspected in patients with the following: Manifestations of portal hypertension without cirrhosis Mild abnormalities in liver function or enzymes plus risk factors such as neonatal umbilical infection, childhood appendicitis, or a hypercoagulability disorder Doppler ultrasonography is usually diagnostic, showing diminished or absent portal vein flow and sometimes the thrombus.