Echogenic or filling-defect material in the portal vein: acute vs chronic (cavernous transformation), extent into the SMV and splenic vein, and whether it is tumour thrombus (enhancing, expanding, next to HCC).
Orient first
- Bland thrombus: cirrhosis, pancreatitis, hypercoagulability, intra-abdominal sepsis.
- Tumour thrombus: enhances after contrast or carries arterial signal, expands the vein, and arises next to HCC.
- Chronic occlusion: cavernous transformation — tortuous collaterals at the porta.
Acquire the study
- Curvilinear probe; colour and spectral Doppler of the main, right and left portal veins, SMV and splenic vein; low PRF.
The manoeuvre
- Grey scale: echogenic material in the lumen (may be anechoic when acute).
- Colour Doppler: absent or partial flow; measure the vein diameter in mm.
- Arterial waveform inside the thrombus on spectral Doppler = tumour thrombus.
- Cavernous transformation: serpiginous collaterals at the porta.
What confirms it
- A filling defect with absent flow in the portal venous system; enhancement or arterial signal makes it tumour.
What licenses you to exclude it
- Normal colour-filling with hepatopetal flow at an appropriate PRF excludes occlusive thrombosis.
The classic misread
- Slow flow in cirrhosis mistaken for thrombosis — lower the PRF and wall filter.