Answer to Question #11414 Submitted to "Ask the Experts"
The following question was answered by an expert in the appropriate field:
My 17-year-old daughter had a computed tomography (CT) scan with and without contrast on her head. I'm terrified this will affect her health long term. Please help, I'm a wreck!
There is no need to feel terrified that your daughter's physicians subjected her to long-term health consequences. The risks of health effects from radiation doses received during diagnostic imaging procedures are either too small to be observed or are nonexistent. The benefits from properly performed, clinically indicated diagnostic imaging procedures, including CT scans, far outweigh any hypothetical cancer risk.
Medical imaging procedures provide a medical benefit to you even if they do not appear to reveal anything, and such procedures are no doubt much less risky than their alternatives, such as exploratory surgery. That nothing was seen gave the physicians information they could use to determine the best next course of action. Refusing medical imaging procedures may result in real and substantial risk by not receiving the clinical benefits of the procedures.
We will not calculate hypothetical risks for diagnostic imaging procedures because the Health Physics Society recommends against quantitative estimation of health risks below 100 millisieverts (mSv), and virtually all diagnostic imaging exams result in doses well below this dose. The Society's position statement "Radiation Risk in Perspective" explains in more detail why it is inappropriate to estimate health risks at these doses.
Kent Lambert, CHP