[Sonographic differential diagnosis of extrahepatic cholestasis]

The value of sonography for aetiological diagnosis was examined in 196 patients with extrahepatic cholestasis. For each patient a diagnosis was prospectively worked out by sonography and compared with the true diagnosis established by endoscopic retrograde pancreaticocholangiography (ERCP), and/or computed tomography (CT), surgical intervention, autopsy and unequivocal clinical course. In 72 patients cholangiolithiasis was the cause of the obstruction. It was diagnosed by sonography with a sensitivity of 86% and a specificity of 93%. With 25 patients with another benign cause of cholestasis the diagnosis was made by sonography in 23 cases. In 93 patients the underlying malignant disease was recognised sonographically with a sensitivity of 95% and a specificity of 100%.