Diagnosis of Portal Vein Thrombosis

Diagnostic Approach

Doppler ultrasound should be used as the first-line investigation for diagnosing portal vein thrombosis, followed by contrast-enhanced CT scan in the portal phase for confirmation and assessment of extension, as recommended by the European Association for the Study of the Liver 1, 2
The American Association for the Study of Liver Diseases recommends that Doppler ultrasound is the first imaging procedure of choice when portal vein thrombosis is suspected, looking for absence of flow within the portal vein and hyperechoic thrombus in the portal lumen 1, 2
Contrast-enhanced CT scan should be used to confirm diagnosis and assess extension, providing critical information about the extent of thrombus to mesenteric veins and arches, presence of local factors, and signs of bowel congestion and ischemia, according to the European Society of Gastrointestinal and Abdominal Radiology 2, 3

Recent thrombus can be identified by clinical presentation with abdominal pain and/or systemic inflammatory response syndrome, spontaneous hyperdense clot in portal vein lumen on non-enhanced CT, and absence of portal cavernoma, as suggested by the American College of Radiology 2
Images acquired during late arterial phase are not optimal for portal vein thrombosis diagnosis, and low portal vein flow can cause delayed contrast arrival, creating a false positive appearance of thrombosis, as noted by the Society of Abdominal Radiology 2

Signs suggestive of intestinal infarction include persisting severe abdominal pain despite anticoagulation, organ failure, massive ascites and rectal bleeding, and CT findings such as distal thrombosis, bowel wall abnormalities, mesenteric stranding, pneumatosis, and portal venous gas, as indicated by the American College of Gastroenterology 2

The European Association for the Study of the Liver recommends performing CT scan at 6-12 months to assess recanalisation of the portal venous system, and screening for gastroesophageal varices in unrecanalised patients 3