Ultrasonic diagnosis of primary intraductal cholelith and neoplasm.

This report presents 19 patients with obstructive jaundice with dilatation of the biliary tree. The obstruction was due to common hepatic duct stones in 14 and intraductal biliary neoplasm in 5. The diagnostic ultrasonographic features consisted of strong echoes with acoustic shadows in a dilated extrahepatic biliary duct for stone and echogenic protrusion into the dilated lumen casting no shadows for neoplasm. The correct diagnoses were made or suggested in 18 patients (94.7%).