Sonographic differentiation of enlarged hepatic arteries from dilated intrahepatic bile ducts.

Identifying parallel tubular structures within the liver by sonography has been regarded as a sensitive and specific sign of intrahepatic duct dilatation. Eight cases are reported in which parallel tubes within the liver were shown not to represent dilated ducts on computed tomography, but rather enlarged hepatic arteries due to increased blood flow. All eight patients had a history of alcoholism and/or cirrhosis and had at least one ancillary sign of portal hypertension. The sonographic findings in these eight patients were compared with similar findings in 12 other patients who were subsequently found to have true intrahepatic bile duct dilatation. Sonographic features that were helpful in distinguishing these two groups are described.