Pneumobilia: a comparison of four imaging modalities.

Computed tomography (CT), ultrasound, radionuclide scans, and plain abdominal radiographs of 25 patients with biliary-enteric anastomoses were reviewed for manifestations of gas in the biliary tree. Patients with biliary-enteric anastomoses are frequently being followed for metastatic disease in the liver. The majority of these patients have free reflux of air into the biliary duct system (pneumobilia). The typical findings of gas in the biliary tree are discussed as seen on each of the aforementioned modalities. The differentiation between findings attributable to pneumobilia itself and those secondary to actual metastatic disease are stressed. There were no discrepancies between radionuclide, CT, and ultrasound diagnoses of liver metastases.