AbstractID: 6692 Title: Risks from Diagnostic X-Rays
Risks from Diagnostic X-Rays
The amount of chromosome damage assayed in the peripheral blood lymphocytes from atom bomb survivors correlates strongly with their increased risk of cancer. An increased risk of cancer has also been associated with high frequencies of chromosome aberrations in the general public. It is distressing, therefor, that contrast enhanced x-ray examinations, including angiography, excretory urography and CT scans, increase significantly the frequency of chromosome aberrations, or micronuclei (MN) derived from them, whether assayed immediately after the examinations or months later.
We have conducted a meta-analysis of ten studies of MN induced by angiography and excretory urography and found a significant increase in the nine that used CM but not in the one without CM, This increase was independent of the specific CM, regardless of whether they were ionic or non-ionic, low or high osmolarity. We conclude that the increased chromosome damage observed after contrast enhanced x-ray examinations is due largely to the photoelectrons from the CM, and is confined to the circulating lymphocytes that were irradiated while suspended in high concentrations of CM. The cancer risk is far less, therefor, than estimates based on chromosome damage assayed in atom bomb survivors who had received whole body radiation.