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Liver vessels on Doppler: portal hypertension, thrombosis and Budd-Chiari
In the liver three vessels are examined — the portal vein (flow toward the liver), the hepatic artery (low resistance) and the hepatic veins (triphasic wave) — and reversed portal flow is the most specific sign of portal hypertension.
Why it matters in the exam
Normal portal vein: flow toward the liver (hepatopetal), monophasic with slight respiratory variation. Portal hypertension: a dilated vein (above 13 mm), slow flow, splenomegaly, ascites and collaterals — a recanalised umbilical vein and veins around the stomach and spleen. The most specific sign — reversed (hepatofugal) flow. In the spleen of portal hypertension small foci of haemosiderin (Gamna-Gandy bodies) are seen, dark on gradient echo. Hepatic veins: a normal triphasic wave; in cirrhosis the wave becomes monophasic; in tricuspid regurgitation and right heart failure the wave is markedly pulsatile.
Portal vein thrombosis: echogenic material within the vein without flow; with time collaterals form around it (cavernous transformation). A tumour thrombus (mainly in HCC) expands the vein and shows arterial flow on Doppler — this distinguishes it from bland thrombus. Budd-Chiari: obstruction of the hepatic veins or the inferior vena cava; the hepatic veins are not seen or have no flow, intrahepatic collaterals ("spider web"), a heterogeneously enhancing ("nutmeg") liver and enlargement of the caudate lobe, which drains directly into the vena cava. In hereditary haemorrhagic telangiectasia (HHT): a dilated tortuous hepatic artery and arteriovenous shunts.
TIPS: indications — refractory ascites and recurrent variceal bleeding despite treatment. Important contraindications: severe heart failure, severe pulmonary hypertension, uncontrolled active infection, severe hepatic encephalopathy and polycystic liver. After TIPS, velocities within the shunt are measured; a sharp fall in velocity or reversal of portal flow back toward the liver suggests shunt stenosis. Splanchnic anatomy: with occlusion at the coeliac origin the liver receives blood from the SMA through the pancreaticoduodenal arcades; compression of the coeliac axis by the median arcuate ligament is seen in deep expiration.
Key points
- Reversed portal flow — the most specific sign.
- Portal vein above 13 mm, collaterals, large spleen.
- Tumour thrombus — expands the vein, with arterial flow.
- Budd-Chiari — blocked hepatic veins, large caudate.
- TIPS — refractory ascites or recurrent bleeding.
Summary table
| Vessel | Normal flow | Abnormal finding | Meaning |
|---|---|---|---|
| Portal vein | Toward the liver, monophasic | Reversed flow; diameter above 13 mm | Portal hypertension |
| Portal vein with thrombus | — | No flow; thrombus with arterial flow | Bland thrombus versus tumour thrombus |
| Hepatic veins | Triphasic | Monophasic; no flow | Cirrhosis; Budd-Chiari |
| Hepatic artery | Low resistance | Dilated artery and shunts | HHT |
| TIPS shunt | Stable velocity within the shunt | Sharp fall in velocity | Shunt stenosis |
In the full version for subscribers
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Sources
- Baveno VII Consensus: Renewing Consensus in Portal Hypertension, 2022 — Non-invasive diagnosis
- AASLD Practice Guidance: Vascular Liver Disorders, Portal Vein Thrombosis, and Procedural Bleeding in Patients With Liver Disease, 2020 — Budd-Chiari and portal vein thrombosis
- AASLD Practice Guidance on the Use of TIPS, 2024 — Indications and contraindications
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.