Porta hepatis: sonographic discrimination of bile ducts from arteries with pulsed Doppler with new anatomic criteria.

Duplex scanning of the porta hepatis was performed in 71 patients, and the identity of the common duct and hepatic artery were confirmed by characteristic pulsed Doppler signals or by tracing structures to known landmarks. In 59% of patients, the hepatic artery was as large or larger than the adjacent normal bile duct, suggesting that the two structures may occasionally be confused. Sonographic signs that help to confirm or support the differentiation of arteries from ducts include observation of intrinsic pulsations of arteries, indentation or displacement of structures by arteries, change in the caliber of bile ducts during real-time examination, and the orientation, contour, caliber, and curvature of the tubular structures of the porta hepatis. Simultaneous identification of the hepatic artery and extrahepatic bile duct using pulsed Doppler or these newly described anatomic criteria improves the diagnostic accuracy of sonography of the porta hepatis.