Ultrasonography in the diagnosis of gallbladder disease.

Ultrasonography is the technique of choice in diagnosing gallbladder calculi. In the mid-1970s ultrasound was only accurate enough to use as an adjunct to oral cholecystography but refinements such as gray scale and real-time imaging mean that in experienced hands it has a sensitivity of 96% and a specificity of 93%. Sonography is also the test of choice in the initial evaluation of jaundiced patients. It is an excellent technique for distinguishing between obstructive and nonobstructive jaundice, although it is less accurate in demonstrating the cause of the obstruction. Ultrasound is painless and relatively inexpensive, and has several advantages over oral cholecystography; it doesn't depend on contrast material, causes no adverse reactions or side-effects, is safe during pregnancy, does not expose the patient to radiation, and is less time-consuming.