Computed tomography, ultrasound, and cholestatic jaundice.

Computed tomography detected the presence of dilated ducts in 15 of 18 cases with extrahepatic obstructive jaundice and demonstrated the obstructing lesion in 18 out of 25. The cause of the obstruction was detected in the absence of duct dilatation, and calculi which were radiolucent on conventional radiographs were demonstrated. Ulstrasound detected dilated ducts in eight of 10 cases, but demonstrated the cause of the obstruction in only one of 13 cases. Both techniques are capable of demonstrating dilated ducts in the majority of cases, but computed tomography is better at detecting the cause of the obstruction.