Answer to Question #13883 Submitted to "Ask the Experts"

Category: Medical and Dental Patient Issues

The following question was answered by an expert in the appropriate field:


Am I getting too much radiation? This week I had two dental CT scans. Next week I am scheduled to have a bone density test and my annual mammogram (3D). Am I overdoing the radiation? Am I getting too much radiation in too short amount of time? Should I cancel any of these appointments?


I can sense that you are quite worried, and I hope I can help ease your concerns. I'll start by first saying that I do not recommend that you cancel any of your appointments.    

To address your other questions, "Am I getting too much radiation? Am I overdoing the radiation? Am I getting too much radiation in too short amount of time?" let's first consider what too much radiation might mean. Too much radiation could mean you want to stay below a dose that would kill you, and that would be a dose of 10 Gy, which equals 10,000,000 µGy. Or too much radiation might mean you want to avoid the possibility of health effects as a result of radiation exposure, and that would mean a dose less than 100 mSv (100,000 µSv). For the purposes of this discussion, you can consider 1 Gy = 1 Sv but please understand there are technical differences between the two. 

Now let's consider how much radiation you have received:

Helpful websites:

Health Physics Society Public Information
IAEA – Radiation of Patients During DXA
National Library of Medicine – Review of Radiation Dose Estimates in Digital Breast Tomosynthesis Relative to Those in Two-View Full-Field Digital Mammography

Your personal exposure total is 63 times lower than the threshold for known health effects from radiation exposure and 6,329 times lower than the lethal dose of radiation. Please understand that this is a significant simplification of a complex topic and that the comparison of your estimated doses to health risks is a very conservative comparison. Based on this conservative estimate you have not received too much radiation.   

Please remember that if a physician is ordering diagnostic imaging then there is clinical health information that the physician is seeking in order to provide the best possible medical care for you. There could be a definite risk associated with not completing an ordered exam that might have immediate implications to your health. The risk for cancer induction at doses above 100 mSv (100,000 µSv) referenced in numerous studies is just a theoretical, statistical risk, not an expected outcome. 

I hope this helps add perspective and understanding to what can be a very complex discussion. I understand that it feels like a lot of radiation in a short time frame, but I hope you can now feel reassured that you do not need to worry about the radiation dose and keep your upcoming appointments. 

Kendall Berry, MSPH, CMLSO

Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. To convert these to traditional units we have prepared a conversion table. You can also view a diagram to help put the radiation information presented in this question and answer in perspective. Explanations of radiation terms can be found here.
Answer posted on 15 March 2021. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.