Portal vein thrombosis (PVT) is the most frequent cause of the prehepatic type of portal hyperten- sion. A group of 22 patients with PVT (18 to 68 years) were examined by colour Doppler ultrasound. Toshiba Sonolayer SSA 270 with 3.75 MHz linear probe and the pulse Doppler method was used. All the patients had a confirmed diagnosis of PVT by another diagnostic procedure (CT, MRI, angio- graphy, laparotomy). We found incomplete PVT in 12 patients, complete PVT in 3 patients and cavernomatous transformation of the portal vein in 7 patients. All patients had oesophageal varices P. III. or IV., 10 patients had one or more episodes of variceal haemorrhage. Development of collateral circulation via portosystemic shunts was often seen. Colour Doppler ultrasonography revealed the highest sensitivity and specificity.

        Key words: portal vein thrombosis - colour Doppler ultrasonography - prehepatic portal hypertension