Gray-scale ultrasonography and thin-needle cholangiography. Evaluation in the jaundiced patient.

Gray-scale ultrasonography (GSU) and thin-needle cholangiography (TNC) were performed in 35 consecutive patients with unexplained jaundice. The status of the biliary tree was correctly assessed by GSU in 33 of 35 cases (94%); in two patients technical difficulty prevented definitive assessment. Neither false-positive nor false-negative results were encountered. There were no discrepancies between the results of GSU and TNC. We conclude that GSU provides a safe, highly reliable method of assessing the jaundiced patient and should be the preferred initial procedure in the diagnostic evaluation of patients with jaundice when the major differential lies between the medical and surgical types. If GSU does not demonstrate a dilated biliary system, TNC is unnecessary, and other diagnostic studies should be undertaken.