A false-positive hepatobiliary scan in a patient with cystic fibrosis.

A case of nonvisualization of the gallbladder in an adult patient with cystic fibrosis in the absence of acute cholecystitis is reported. Delayed images to 20 hours showed persistent nonvisualization. Review of the literature on cystic fibrosis suggests that nonvisualization of the gallbladder may be secondary to inspissated mucus rather than acute cholecystitis, and therefore a positive hepatobiliary scan in these patients should be interpreted with caution.