AJR:182, June 2004 1555 Oral Contrast Agents for CT of Abdominal Trauma in Pediatric Patients: A Comparison of D ilute H ypaque and W ater OBJECTIVE. Dilute Hypaque Sodium is generally well accepted as an oral contrast agent for CT of pediatric patients who have experienced recent blunt abdominal trauma. However, Hypaque can cause complications. Using water as a substitute contrast agent eliminates these potential complications. The purpose of our study was to compare the performance of water with that of dilute Hypaque as an oral contrast agent. Our hypothesis was that we would find no significant difference in performance between the two agents in defining anatomic details of the hollow gastrointestinal tract. MATERIALS AND METHODS. We performed a retrospective review of 74 CT scans obtained in infants and children who had received blunt abdominal trauma, scoring the quality of visualization of bowel structures, the presence of non–bowel-related findings, and the con- fidence level in making each assessment. The date range of the scans reviewed overlapped with the period in which the oral contrast material used for scanning such patients was switched from dilute Hypaque to water. Of the 74 CT scans that we reviewed, 53 were ob- tained with dilute Hypaque and 21 were obtained with water. The sex distribution between the two groups was compared using a chi-square test, whereas the mean age was compared using a two-sample two-sided Student’s t test. A two-sample one-sided Student’s t test of equiva- lence was used to analyze the data. RESU LT S. Sex distribution for the two groups of patients was not significantly different (69.81% of the group who received dilute Hypaque were boys; 68.18% of the group who re- ceived water were boys). Furthermore, the difference in the mean age for the two groups was not statistically significantly (dilute Hypaque group, 8.86 years; water group, 10.18 years). No statis- tically significant difference in performance of the contrast agents was found with respect to the detection of intraabdominal abnormality. As an oral contrast material, water performed as well as dilute Hypaque in facilitating visualization of all intraabdominal anatomic structures. CONCLUSION. In defining anatomic details of the hollow gastrointestinal tract, water is as effective as dilute Hypaque as an oral contrast agent for CT in the setting of acute blunt abdominal trauma in pediatric patients. he administration of an oral con- trast agent is generally accepted as useful in the CT evaluation of the gastrointestinal structures. However, the opacification of the small bowel is often lim- ited [1, 2]. Many positive contrast agents have been evaluated. Results of studies com- paring the performance of barium suspen- sion with that of iodinated water-soluble contrast material suggest that the perfor- mance of these agents is similar [1, 3]. A study comparing sodium amidotrizoate, io- hexol, and iohexol combined with a viscosity agent found that these agents also offered similar performance characteristics [4]. Negative agents also have been studied in adults, and water has been shown to be an ef- fective negative contrast agent [5]. In a study evaluating water, dilute Calogen ([banana oil], Scientific Hospital Supplies; another negative contrast agent), and sodium diatri- zoate (a positive agent), Calogen was found to be superior for showing the gastric wall and for evaluating the proximal duodenum, but all three agents had similar performances for evaluation of structures beyond the mid portion of the duodenum [2]. Use of any oral contrast agent poses a small risk of aspiration [6–8]. This risk is one reason that some have questioned whether it is neces- Mark J. Halsted 1,2 John M. Racadio 1,2 Kathleen H. Emery 1,2 Peter Kreymerman 3 Stacy A. Poe 4 Judy A. Bean 4 Lane F. Donnelly 1,2 Received October 9, 2003; accepted after revision December 1, 2003. 1 Department of Radiology, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229- 3039. Address correspondence to M. J. Halsted. 2 Department of Pediatrics, Cincinnati Children’s Hospital M edical Center, Cincinnati, OH 45229-3039. 3 Department of Surgery, Cleveland Clinic Foundation, Cleveland, OH 44195. 4 Center for Epidemiology and Biostatistics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229-3039. AJR 2004;182:1555–1559 0361–803X/04/1826–1555 © American Roentgen Ray Society T Downloaded from www.ajronline.org by 52.73.204.196 on 05/17/22 from IP address 52.73.204.196. Copyright ARRS. For personal use only; all rights reserved