UPPER GASTROINTESTINAL-TRACT AND ABDOMEN - WATER AS AN ORALLY-ADMINISTERED CONTRAST AGENT FOR HELICAL CT

PURPOSE: To evaluate the use of orally administered water as a negativ e contrast agent and intravenously administered glucagon in helical co mputed tomography (CT) of the upper abdomen. MATERIALS AND METHODS: Ni nety-eight adult patients underwent 102 helical CT examinations. Patie nts received 700 mt of water orally 30 minutes before and another 350 mt of water orally with 1 mg of glucagon intravenously just before CT. The amount of water actually ingested was recorded. Luminal distentio n at five sites was graded on a three-point scale; depiction of six no rmal anatomic structures was evaluated. RESULTS: Luminal distention im proved with the amount of water ingested in four of the five sites (P < .03 in three sites). Depiction of all six normal anatomic structures improved with increasing luminal distention (P < .001). The normal du odenal papilla was seen in 42% (83 of 198) of the examinations. Of 87 patients who had previously undergone CT with positive oral contrast a gents, 89% (n = 77) preferred the water, 11% (n = 10) had no preferenc e, and none preferred the positive agent (P < .001). Upper gastrointes tinal tract abnormalities were easily recognized and depicted. CONCLUS ION: Water is an efficacious negative contrast agent for evaluation of the upper gastrointestinal tract during helical CT.