Intracisternal application was used to estimate the neurotoxicity of contrast media. To compare with so-called “systemic” toxicity, the intravenous route also was used. Four hundred rats were studied with sodium diatrizoate, methylglucamine diatrizoate, sodium iothalamate and methylglucamine iothalamate. The results indicate that, intracisternally, the sodium and diatrizoate ions are more toxic than methylglucamine and iothalamate ions, and the toxicity increases with increasing concentration, both in the hypertonic and hypotonic ranges. With the same dose, in terms of mg/kg body weight, large rats responded more frequently than small adult rats, presumably because both groups had the same brain weight (approximately 1.6 Gm). The data emphasize the necessity of taking into account the molal concentrations (determinant of iodine concentration and thus the radiopacity) as well as brain weight of the experimental animals in estimating the relative neurotoxicity of different media. A new index to express the relative neurotoxicity of a contrast agent has been proposed and the significance of this new index has been discussed. In systemic use, the iothalamate salt was less toxic than the diatrizoate salt. Methylglucamine iothalamate was more toxic in systemic use than sodium iothalamate in the high concentrations used in our experiments.
- Cerebral angiography
- Cerebrospinal fluid
- Contrast media
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging