title: Use of iohexol in the radiographic diagnosis of ischemic bowel.
abstract: This study evaluates the use of iohexol as a radiographic diagnostic contrast agent in normal animals and those with experimental bowel ischemia and obstruction. Eighteen rats and 12 rabbits were gavaged with iohexol in a dose of 7.5 mL/kg using concentrations of 140 mg I/mL (isotonic with blood) or 300 mg I/mL. In addition, four rabbits had intraperitoneal iohexol injection and three were given gastrografin gavage. Experimental groups included normal bowel controls, bowel injury induced by ischemia and alcohol contact, bowel obstruction by ligature, and intraperitoneal injection. Serial abdominal radiographs and plasma concentrations of iohexol were obtained. Iohexol remained stable throughout the gastrointestinal tract, retained its intensity, and was well visualized up to four days after administration. Bowel images were fair at concentrations of 140 mg I/mL and excellent at 300 mg I/mL. Gastrografin caused bowel distention and poor visualization related to dilution. It also precipitated in the stomach. Iohexol was rapidly absorbed from the peritoneal cavity and excreted by the kidneys, without causing peritonitis. Rat plasma iohexol levels were three times controls in obstructed bowel and 80 times controls if there was mucosal injury without perforation. Rabbit peak plasma levels were 30 times greater following intraperitoneal injection than with gastric gavage. These observations suggest that iohexol may be useful as a gastrointestinal contrast agent. Measuring plasma iohexol levels may be helpful in the evaluation of suspected bowel ischemia or perforation in the clinical setting.
mesh_terms: D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D003974:Diatrizoate Meglumine; D004195:Disease Models, Animal; D004341:Drug Evaluation; D007415:Intestinal Obstruction / Q000000981:diagnostic imaging; D007421:Intestine, Small / Q000098:blood supply* / Q000000981:diagnostic imaging; D007463:Iodobenzoates; D007472:Iohexol; D007511:Ischemia / Q000000981:diagnostic imaging*; D008297:Male; D011817:Rabbits; D011859:Radiography; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014283:Triiodobenzoic Acids / Q000097:blood
chemical_list: D003287:Contrast Media; D007463:Iodobenzoates; D014283:Triiodobenzoic Acids; D003974:Diatrizoate Meglumine; D007472:Iohexol