Ultrasonic examination of the gallbladder: a review.

Ultrasonography is a helpful, non-invasive, and relatively inexpensive adjuvant to oral cholecystography for evaluating the gallbladder and its diseases. This method can be highly accurate in detecting gallstones and is specially useful when there is non-visualisation in radiographic contrast studies. Various ultrasound patterns of gallstones are described. All these patterns should demonstrate a sonic shadow in association with an intraluminal defect. Sonography is particularly useful in demonstrating cholelithiasis and organ dilatation in suspected acute cholecystitis. In addition to gallbladder disease, this technique simultaneously offers pertinent anatomical information about the porta hepatis. This information would otherwise require additional diagnostic investigation. Because, in many instances, sonography is non-specific, or blind to certain gallbladder non-calculous filling defects, and because of present lack of uniform standard quality control methods for performing this procedure, it should be considered only as a complementary, imaging procedure to oral cholecystography.