The accuracy of sonography in the differential diagnosis of obstructive jaundice: a comparison with cholangiography.

The value of sonography in determining the site and nature of biliary obstruction with surgical jaundice is described in 32 patients. All diagnoses were subsequently established by surgery and pathology. The site of obstruction was delineated in 94%, while the nature of the lesion was established in 81%. In comparison, contrast cholangiography correctly delineated the site in 96%, but helped determine the etiology in only 82%. Sonography is sufficient to adequately evaluate patients prior to surgery, while percutaneous transhepatic cholangiography should probably be used only when satisfactory ultrasound examinations cannot be obtained.