Answer to Question #13235 Submitted to "Ask the Experts"
The following question was answered by an expert in the appropriate field:
I am eight weeks pregnant, and I have to go with my father to a different city for his positron emission tomography/computed tomography (PET/CT) scan of his abdomen with fluorodeoxyglucose (FDG). Should I stay in the same room after the scan? What other precautions do I take?
You and your baby will not be at risk from your father's scan. You may follow some simple precautions to keep you and your baby's exposure to radiation very, very low. For a standard PET/CT scan using FDG, your father will be injected with a small amount of fluorine 18 (18F), which is radioactive. It has a very short half-life, meaning it does not remain radioactive for very long. First, he will receive an injection, which includes the radioactive material. At that point, he will be a source of radiation over the next 24 hours, but even so the exposure to you and your baby will be very low.
If you stay at least one meter away for the first 24 hours after the injection, your exposure would be about the same as three weeks of the radiation exposure we all receive from the natural radioactive materials in our environment, and about 4% (or 1/25th) of the exposure that is allowed to pregnant workers who routinely work with radiation. Brief hugs during that period, or helping him into the car, will not significantly increase that exposure. If you have a long drive after the scan is over, one of you should sit in the driver's seat and the other on the passenger side in the back seat of the car.
After the injection, and while he is waiting for the scan is when he will have the highest amount of radioactive material. There may be other patients in the waiting area who are also radioactive, so during that period, you may want to wait two meters or more from him and the other patients in the area.
I hope this answer helps to put your mind at ease. My best wishes to you, your baby, and your father.
Barbara Hamrick, CHP