Diagnostic Criteria for Portal Vein Thrombosis

Initial Imaging Approach

Doppler ultrasound is the mandatory first-line diagnostic test for portal vein thrombosis, followed immediately by contrast-enhanced CT scan in the portal venous phase for confirmation and complete characterization 1, 2, 3, 4
The American Association for the Study of Liver Diseases recommends Doppler ultrasound findings diagnostic of PVT include absence of flow within the portal vein lumen, hyperechoic thrombus visible within the portal vein, and flow reversal within the portal system 2, 3, 4
Proceed immediately to contrast-enhanced CT scan for definitive diagnostic confirmation, assessment of thrombus extension to mesenteric and splenic veins, identification of local causative factors, and detection of bowel ischemia or congestion 2, 3, 4

Acute thrombosis is characterized by clinical presentation with abdominal pain, systemic inflammatory response syndrome, spontaneous hyperdense clot visible in portal vein lumen on non-enhanced CT, and absence of portal cavernoma formation 1, 2, 3, 4
Chronic thrombosis demonstrates presence of portal cavernoma, absence of acute inflammatory symptoms, and is often asymptomatic 1, 2, 3

The European Association for the Study of the Liver recommends differentiating benign thrombus from malignant portal vein invasion using arterial phase hyperenhancement within the thrombus and high signal intensity within the obstructed vessel on diffusion-weighted MRI with high b-values 3, 5

Evaluate for intestinal ischemia using criteria such as persistent severe abdominal pain despite anticoagulation, organ failure, massive ascites or rectal bleeding, and CT findings of distal mesenteric thrombosis, bowel wall abnormalities, mesenteric stranding, pneumatosis intestinalis, or portal venous gas 2, 4

Complete diagnostic assessment must determine whether occlusion is partial or complete, which vessels are involved, and presence of ascites 1, 2
The American College of Gastroenterology recommends assessing the extent of thrombosis, identifying underlying causes, and detecting complications that directly impact mortality and morbidity 1, 2

Structured surveillance includes CT scan at 6-12 months to assess portal venous system recanalization, Doppler ultrasound early after diagnosis and every 6 months for ongoing surveillance, and screening for gastroesophageal varices in patients with persistent occlusion 2, 3, 4

In patients with compensated advanced chronic liver disease, liver stiffness measurement by transient elastography with cut-off >20-25 kPa can diagnose clinically significant portal hypertension, and LSPS score >2.06 has 90% specificity for portal hypertension 2