comparison of allergic adverse effects and contrast enhancement between iodixanol and iopromide

background iodinated x-ray contrast media are the most commonly used contrast agents in the world with an annual application of 40-50 million. new non-ionic con- trast agents are subdivided into low osmolar agents such as iopromide and iso-osmolar agents such as iodixanol. regarding different biochemical characteristics, these agents are different in the allergic reactions and contrast enhancement and final lesion conspicuity. objectives this study was carried out to compare allergic adverse effects and contrast enhancement between iodixanol and iopromide. patients and methods one-hundred and twenty patients who were referred for abdominal ct scan to besat hospital were included in this study. patients were randomly divided into two groups (a and b). group a received 100 cc iodixanol (300 mgi/ml) and group b received 100 cc iopromide (300 mgi/ml) by power injector. ct examination was performed using helical ct scanner (somatom, siemens, germany). sixty seconds after injection, images were obtained and enhancement of port, liver and aorta were determined. allergic adverse effects were recorded one hour and up to one week after injection. results iodixanol produced a significantly greater enhancement of the hepatic, aorta and portal vein than iopromide (p < 0.01). sixty seconds after injection, associated pain and heat sensation were less frequent in iodixanol in comparison with iopromide (p = 0.03). immediate reactions such as nausea and vomiting were less frequent in iodixanol (p = 0.01). late skin reactions such as rash was more frequent in iodixanol (p < 0.01). conclusions iodixanol is safe and is better tolerated in the early phase of injection with better contrast enhancement and lesion conspicuity. mild late skin rash is its disadvantage.