How to image the gallbladder in suspected cholecystitis.

As a result of important advances in medical imaging, the oral cholecystogram is no longer the primary test of gallbladder function and anatomy. Real-time ultrasonography and cholescintigraphy, both highly sensitive and specific tests, are the two major methods for assessing gallbladder pathology. Oral cholecystography, endoscopic retrograde pancreatography, and percutaneous gallbladder puncture serve as supplementary tests. Decisions about which test to use depend on the kind of gallbladder disease that is suspected as well as the estimated likelihood of the disease before the information is obtained from the procedure. Thus, ultrasonography is the test of choice for chronic cholecystitis, with oral cholecystography reserved for situations in which the diagnosis is uncertain after ultrasonography. When acute cholecystitis is suspected, ultrasonography is also the test of choice in most patients, and cholescintigraphy is used to resolve uncertainty.