Answer to Question #2846 Submitted to "Ask the Experts"

The average dose to the ovaries from a barium enema is usually in the range of 200 to 2,000 mrad. The dose to the ovaries depends on the number of x rays taken, the amount of fluoroscopy time used, and how often the ovaries are in the x-ray beam. To make an exact determination of the dose would require specific information about the procedures done, the characteristics of the x-ray machine used, the size (thickness) of the patient, and the orientation of the patient with respect to the x-ray beam for each exposure.

These procedures expose only a small portion of the body to the x-ray beam. The dose indicated above is the dose to that portion of the body that is in the x-ray beam; the rest of the body receives very little radiation dose during the procedure. If the dose to a small portion of the body is averaged over the entire body to estimate risk from the radiation exposure, the result is an averaged dose to the whole body that is much lower than the dose to the small portion of the body exposed to the x-ray beam. This leads to a misleading understanding of the risk involved.

To offer a comparison of risk, a typical yearly background radiation dose of 300 mrad to the whole body is considered. Background radiation is radiation that we continuously receive from cosmic rays, radioactive materials present in the earth and building materials, and radioactive materials normally present within our own bodies. The mrad is a measure of radiation dose, i.e., energy deposited in tissue in this case, from any type of ionizing radiation, including x rays. The individual that you talked to apparently knew what the yearly background radiation dose is and how much radiation you received from the procedure. This person put your dose in terms of yearly background radiation exposure.