The characterization of pancreatic and bile duct tumours by duplex Doppler.

Duplex Doppler imaging was used to study the effect of pancreatic and bile duct tumours on portal vein and hepatic artery blood flow and the specific Doppler signals recorded from these tumours. Chaotic portal vein flow occurred in 35% (14) of pancreatic and 20% (6) of biliary tumours and complete portal vein occlusion in 28% (11) and 10% (3) respectively. Twenty-eight per cent (11) of pancreatic and 7% (2) of bile duct tumours had high frequency shift Doppler signals and 22% (9) of pancreatic tumours had a signal indicating low impedence flow. Both signal types are suggestive of malignancy. The results suggest that pulsed Doppler imaging has a valuable place in the ultrasound assessment of portal vein wall invasion, is an important staging criterion for pancreatic and biliary tumours and may assist in differentiating benign from malignant lesions.