Winklhofer S, et al. - In this investigation, researchers compared the quality of bowel opacification at abdominopelvic CT from three different positive oral contrast agents—barium sulfate, diatrizoate, and iohexol. Two independent readers retrospectively evaluated abdominopelvic CT examinations with three different oral contrast agents of 900 patients. Using iohexol as the oral contrast agent, fewer artifacts were detected than diatrizoate and barium sulfate. Barium exhibited higher CT attenuation in the stomach than iohexol and diatrizoate but lower CT attenuation in the ileum. The inhomogeneous bowel opacification frequency for iohexol was lower than for diatrizoate or barium sulfate. Barium displayed the highest frequency of bowel lumen heterogeneity. From the proximal bowel segments to the distal bowel segments, the iodinated agents showed greater increases in mean CT attenuation than barium sulfate.