Acta radiologica. Supplementum最新文献

The chemotoxicity of iodinated contrast agents is essentially related to the spatial accessibilty of lipophilic and polarizable iodine atoms. This accessibility was examined in iobitridol by HPLC and 1H- and 13C-NMR spectroscopy,taking into account both the static distribution of the hydrophilic groups around the triiodinated benzene ring and in particular the dynamic modulation of this distribution. The aim of this latter parameter is to prevent distortion of the hydrophilic sphere of nonionic agents when faced with a hydrophobic environment. Iobitridol is characterized by 2 tertiary carbamoyl substituents whose high rotation barriers (deltaG*353=27.6 kcal for E/Z-rotation and deltaG*345=17.3 kcal for syn/anti-rotation) stabilize the hydrophilic sphere. The 3rd dihydroxylated anilide substituent does not undergo SMILES rearrangement and provides iobitridol with its even hydrophilic distribution. Iobitridol presents remarkable chemical solubility (>140% m/v) and stability. The iobitridol molecule was specifically designed with the aim of stabilizing the hydrophilic sphere around the triiodinated benzene ring, therefore permanently masking access to the iodine atoms. This new concept represents a further step forward towards the synthesis of new iodinated contrast agents which should be totally inert vis-a-vis biological membranes and proteins.

Purpose: The purpose of this double-blind, randomized parallel trial was to evaluate and compare the clinical safety and the diagnostic efficacy of the new nonionic triiodinated contrast agent iobitridol (300 mg I/ml) with those of iohexol (300 mg I/ml) in CT examinations in children.

Material and methods: Eighty children of either sex were included in the study. Of those, 40 patients received iobitridol, 40 iohexol. Mean volume injected i.v. was 1.8 ml/kg b.w. Adverse reactions occurring during 24 hours after the injection of the contrast agent were recorded.

Results: Image quality was judged good or excellent in all study examinations and all were diagnostically informative. There was no significant difference in clinical safety between the 2 groups and only adverse reactions of mild or moderate intensity were reported in both groups.

Conclusion: Iobitridol appears to be a safe, well tolerated and effective contrast agent, when used for brain and body CT in children.

Purpose: Evaluation of imaging quality and safety of iobitridol 300 compared to iohexol 300 in urography.

Materials and methods: 180 patients were included in an urography multicenter study (3 centers, 60 patients in each).

Results: There was no significant difference in either the imaging quality or the clinical safety between the 2 contrast media groups.

Conclusion: Iobitridol is a safe and efficient contrast agent in urography.

The present article combines and summarizes the preclinic studies carried out in vitro and in vivo to determine the pharmacologic and biochemical profile of iobitridol, a new nonionic iodinated low-osmolality contrast medium (CM). The effects of this product on the main hemodynamic, bronchopulmonary, neurologic, renal, blood chemistry and electrophysiologic parameters and RBC morphology were studied in detail in comparison with CM in the same chemical category or with reference substances of the same osmolality. The in vivo studies were performed under conditions resembling clinical use. Iobitridol showed an excellent pharmacologic and biochemical profile, which was identical or superior to that of other products in its category.

Variations in the size and shape of the human vestibular aqueduct were evaluated in 118 plastic casts of unselected specimens of human temporal bones. They were examined by conventional radiography and by high resolution CT. The degree of the mastoid and perilabyrinthine pneumatization was defined and classified into 3 types. The dimensions of the peripheral portion of the aqueduct were found to be related to the extent of the perilabyrinthine pneumatization.

Iobitridol 250 (Xenetix 250) was compared with iohexol 240 (Omnipaque 240) in phlebography of the lower limbs by means of a multicenter, randomized double-blind trial in 70 patients. No significant difference was demonstrated between the 2 groups in terms of diagnostic efficacy, image quality or clinical safety. Only minor reactions were recorded in the 2 groups, essentially consisting of mild or moderate heat sensations. The only insufficiently informative examinations were not due to the contrast agent. Iobitridol 250 therefore appears to be a well-tolerated contrast medium, suitable for use in phlebography of the lower limbs.

Purpose: A new nonionic low-osmolality contrast medium, iobitridol (Xenetix 350) was compared with iohexol (Omnipaque) after i.v. injection in anesthetized rabbits to assess efficacy in CT examinations and biodistribution.

Material and methods: The densities in test tubes and the pharmacogenetics and biodistribution of iobitridol 350 and iohexol 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 roentgen rays in a manner exactly identical to that of iohexol. Within 15 min following injection of iohexol and iobitridol at a dose of 300 mg I/kg, both contrast agents resulted in aortic enhancement which decreased with time. An increased attenuation of the liver also occurred, decreasing with time. There was no significant enhancement in the brain but enhancement was found in the renal pelvocalyceal cavities 10 min postinjection. No significant difference was found between the 2 contrast agents under the study conditions.

Conclusion: As could be expected from its behavior as a tracer of extracellular fluid, iobitridol resulted in significant changes in the signal, corresponding to its vascular, hepatic and renal pharmacokinetics in rabbits.

Purpose: The diagnostic efficacy and the clinical tolerance of iobitridol 300 was evaluated in 68 patients receiving intraarterial injection in 2 monocentric comparative randomized double-blind trials with iopromide 300 (30 patients) and iopamidol 300 (40 patients) as reference. RESULTS; There is no significant difference in quality of opacification or in diagnostic efficacy between the products in each trial. No major adverse reactions occurred after the injection of iobitridol 300. Excluding a heat sensation, 5 of the patients who received iobitridol had minor reactions consisting of nausea with vomiting and pain during the injection. Five patients in the reference group also experienced adverse events.

Conclusion: Iobitridol is well tolerated after intraarterial administration and it has the same diagnostic quality as iopromide and iopamidol.