Talk with your care team if you have questions about medical imaging tests and radiation exposure.
Certain medical imaging tests expose us to radiation. Overexposure to radiation can be a cause of cancer, so it’s good to be aware when you have a medical test that exposes you.
Marshfield Clinic Health System radiation oncologist Dr. Patricia Lillis said we are all exposed to radiation every day whether or not you have a medical imaging test done. Radiation from the sun and radon, a gas, are natural sources of exposure we all experience. Radiation exposure is slightly greater for people who live at higher altitudes.
What tests expose you to radiation?
“In medical imaging tests, you are exposed to a variable amount of radiation depending on the test,” Lillis said. “Each study requires a different amount of radiation to produce the desired image.”
Lillis said MRIs and ultrasounds do not use radiation, while X-rays, CT scans and nuclear imaging tests do. Harvard Medical School published a chart showing the average dose of radiation exposure in multiple different tests.
The unit of measurement for radiation is a millisievert. The average person is exposed to about 3 millisieverts of radiation each year.
Body part and body type matter
Lillis said different areas of the body are more or less sensitive to radiation. The hands and skin, for instance, can tolerate more than the eyes or sexual organs. She added that your body composition also factors into your exposure. More radiation is required to produce an image for larger individuals.
Weigh the risk
With multiple scans, your level of radiation exposure can add up.
“You have to balance the potential risk of exposure against not finding out whatever potentially bad disease you may have,” she said. “It may be worth the risk. It’s a risk-benefit ratio.”
Lillis said it is important providers and patients talk through options and ensure unnecessary tests are not ordered. If you have questions about an imaging test you may need, discuss it with your care team.
What about yearly dental X-rays, are they dangerous?
Hi Joan,
Thanks for reaching out and reading Shine365. We asked Dr. Lillis and she said that in general — no, dental x-rays are not too dangerous. The doses are very low, but she does recommend reaching out to your dentist to learn more about why the x-rays are done and how often you should be getting them.
Thanks!
Jake
I had 33 sessions of radiation after breast cancer surgery. Do you know what long range effects that may have?
Hi, Vicki. Thank you for reaching out. We cannot discuss individual health issues on the blog, and would need more detailed information to accurately answer your question. Dr. Lillis said other factors impact long-range effects and suggested you talk to your oncologist. She said long-term complications are discussed as part of the consent process; your oncologist would be able to remind you of these conversations.
If you cannot speak to your oncologist, we welcome you to come in for a visit/consult: https://marshfieldclinic.org/appointments
Thank you for reading Shine365. -Kirstie
If I was on jury awarding damages to a victem of radiation caused by a radiolgist they would get plenty. chiropracters have honesty than you folks.
Is having 2 CT scans done within 3 months safe?
Thank you for reaching out, Nancy.
I shared your question with Dr. Lillis. Though we cannot provide individualized medical advice on this forum, she said: In general, yes, it is safe. However, to accurately answer your question, we’d need more information, like which type of x-rays and CT scans you experienced. To get an informed, accurate answer, bring this question and similar questions to your care team.
-Kirstie
I've had approximately 50 x-rays throughout my lifetime and about 8 MRI's, am I at risk? I realize the MRI's are magnetic imaging but I thought I should include it anyway.
Hi, Ginna. Dr. Lillis' response to your question was, "What risk are you concerned about?"
Essentially, she'd need more information to accurately answer your question, like which type of x-rays and scans you received. Additionally, a “lifetime” and “risk” would vary between a 70-year-old and a 10-year old.
To get an informed, accurate answer, bring this question and similar questions to your care team, or come in for a visit/consult (https://marshfieldclinic.org/appointments), as we cannot discuss individualized medical advice on the blog.
Thank you for reading Shine365. -Kirstie
I'm 64 and the x-rays were regular x-rays using radiation. The others were MRI's and the donut machine which I cannot remember the name of at the moment. I've had about 5 of them (donut).
What about yearly mammograms. Is that really safe
Hi, Carol. Yes; yearly mammograms are safe and are important in detecting cancer. American Cancer Society provides more information on these guidelines: https://www.cancer.org/latest-news/special-coverage/american-cancer-society-breast-cancer-screening-guidelines.html
Thank you for reading Shine365. -Kirstie