Intrahepatic versus extrahepatic cholestasis. Discrimination with biliary scintigraphy combined with ultrasound.

Biliary scintigraphy and ultrasound imaging were performed in 52 patients with suspected biliary tract pathology. Results were correlated with the findings of direct cholangiography. Several new innovations in scintigraphic technique were used. The combination of ultrasound imaging and scintigraphy correctly identified biliary tract obstruction in 17 of 19 patients, 12 of whom had dilated bile ducts on ultrasonography. Intrahepatic cholestasis was correctly diagnosed in 11 of 13 patients. Accurate discrimination between intrahepatic and extrahepatic cholestasis was achieved in 28 of 32 patients (88%) with the combined studies. Scintigraphy also provided a correct diagnosis of acute cholecystitis in all 9 patients with surgically confirmed disease. Eleven additional patients with gallbladder or pancreatic disease had normal bile ducts at scintigraphy, which was confirmed with cholangiography. When combined with ultrasound imaging, modern biliary scintigraphy can (a) provide excellent discrimination between intrahepatic and extrahepatic cholestasis and (b) help determine the need for subsequent invasive diagnostic studies in selected patients.