TIME-COURSE OF BIODISTRIBUTION AND CHANGES IN DENSITY FOLLOWING ADMINISTRATION OF IOBITRIDOL IN RABBITS - A COMPARATIVE-STUDY VS IOHEXOL

Purpose: A new nonionic low-osmolality contrast medium, iobitridol (Xe netix 350), was compared with iohexol (Omnipaque 350) after i.v. injec tion in anesthetized rabbits to assess efficacy in CT examinations and biodistribution. Material and Methods: The densities in test tubes an d the pharmacogenetics and biodistribution of iobitridol 350 and iohex ol 350 were compared in rabbits, CT of the brain, liver, the abdominal aorta and the kidneys was performed before and after injection of the contrast media. Results: In aqueous medium, iobitridol absorbed roent gen rays in a manner exactly identical to that of iohexol. Within 15 m in following injection of iohexol and iobitridol at a dose of 300 mg l /kg, both contrast agents resulted in aortic enhancement which decreas ed with time. An increased attenuation of the liver also occurred, dec reasing with time. There was no significant enhancement in the brain b ut enhancement was found in the renal pelvocalyceal cavities 10 min po stinjection. No significant difference was found between the 2 contras t agents under the study conditions. Conclusion: As could be expected from its behavior as a tracer of extracellular fluid, iobitridol resul ted in significant changes in the signal, corresponding to its vascula r, hepatic and renal pharmacokinetics in rabbits.