Rationale and objectives: The hypothesis that nonionic contrast medium administered during excretory urography may cause cytogenetic damage was tested.
Methods: Micronuclei were scored in peripheral blood lymphocytes obtained from 33 patients before and after excretory urography with ioversol, a nonionic contrast medium.
Results: The examination resulted in a highly significant (sign test, P = .005) increase in the median (range) counts of micronuclei per 1,000 binucleate from 18 (0 to 31) before to 24 (5 to 40) after excretory urography.
Conclusions: Nonionic ioversol produces a statistically significant increase in the chromosome damage of lymphocytes from patients undergoing excretory urography. This increase is similar to that reported for the ionic contrast media, ioxaglate and iothalamate, and equal to that produced by 6 to 7 cGy of 100-kilovolt x-rays.