Gallstone imaging: getting the most out of the oral cholecystogram.

The introduction of "nonoperative" treatment alternatives to elective cholecystectomy (extracorporeal shock wave lithotripsy, contact dissolution of stones, and improved oral bile salts solvents) has reinstated the oral cholecystogram as an important diagnostic test providing structural and functional information on the status of the gallbladder. The basic principles involved in the proper performance and interpretation of the oral cholecystogram are reviewed from the perspective of the clinician who orders the test and makes management decisions based on its results.