Morphine-augmented cholescintigraphy in the diagnosis of acute cholecystitis

Cholescintigraphy is a sensitive procedure for diagnosing or excluding acute cholecystitis. However, when rapid diagnosis is critical, the requirement for delayed images (4 hr or more after injection) to minimize the false-positive rate diminishes its utility. We prospectively evaluated 40 cholescintigraphic examinations that did not visualize the gallbladder 1 hr after injection of 99mTc diisopropyliminodiacetic acid. These examinations were then augmented by administration of IV morphine, followed by an additional 30 min of imaging. After the morphine, 18 of these examinations demonstrated visualization of the gallbladder; none subsequently required surgical exploration. Of the remaining 22, who demonstrated persistent nonvisualization of the gallbladder post-morphine, 11 were explored surgically and found to be abnormal. The 11 others were treated medically. Low-dose morphine administered when the gallbladder fails to visualize after 1 hr is a useful adjunct to conventional cholescintigraphy because it reduces the time required to obtain a diagnostic result and decreases the number of false-positive results.