Radiation doses from nuclear medicine patients to an imaging technologist: relation to ICRP recommendations for pregnant workers.

The ICRP has now recommended that the dose limit to the surface of the mother's abdomen during the declared term of pregnancy is reduced to 2 mSv. Direct measurements of the radiation dose to technologists carrying out a variety of imaging studies were made. The average dose ranged from 0.3 micro Sv for a liver scan to 5.3 micro Sv for a brain scan. Using national data for the frequency of nuclear medicine studies, a weighted average figure of 1.5 micro Sv per study was derived. A technologist could therefore perform approximately eight imaging studies per day during the declared term of her pregnancy and remain within the proposed limit. Generally, there should be no need to alter a technologist's duties during her pregnancy, and these findings should be helpful in allaying any anxiety.