Answer to Question #12043 Submitted to "Ask the Experts"

Category: Medical and Dental Patient Issues — Diagnostic X Ray and CT

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

Q

I was involved in a car accident a few weeks ago and received a spine x ray. It was two cervical, thoracic, and lumbar images with a digital computed radiography machine for a total of six images. I am now sincerely regretting that x ray, as I could have avoided it. These are the only body x rays I've ever had, I've never had computed tomography (CT) scans, and I ceased having dental x rays a few years ago as I don't need them.

I'm 27 years old. I've been in sports all my life, I train intensely seven days a week, I follow an all-plant diet, I don't drink or smoke, and there's no history of cancer in my family.

I take my health very seriously, and I regret not being proactive about requesting nonradiation imaging. I can't stop worrying that I've exposed myself to a harmful amount of radiation that will lead to complications in the future. My question is whether or not I've doomed myself to cancer in the future by agreeing to the x rays I had? I can't stop worrying.

A

I am sorry to hear about your automobile accident. My vehicle was recently totaled when a texting driver rear-ended me, so I know how disruptive an accident can be. But you can stop worrying about your x-ray exams—they have not doomed you to a future cancer.

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. Diagnostic medical imaging procedures provide a medical benefit to you even if they do not appear to reveal anything, and they are of less risk than their alternatives, such as exploratory surgery.

The typical effective dose from the procedures you underwent is around 2 millisieverts (mSv). The average annual effective dose from naturally occurring radiation in the environment is 3 mSv (in the United States). In other words, you received more radiation by staying alive for a year than you did from having these x-ray exams.

The Health Physics Society's position statement Radiation Risk in Perspective states that "below levels of about 100 mSv above background from all sources combined, the observed radiation effects in people are not statistically different from zero." In other words, the risk, if it exists, is too small to be seen.

The American Association of Physicists in Medicine (AAPM) is an organization of professionals dedicated to assuring that radiation is used safely in medicine. AAPM's position is that "risks of medical imaging at effective doses below 50 mSv for single procedures or 100 mSv for multiple procedures over short time periods are too low to be detectable and may be nonexistent. Predictions of hypothetical cancer incidence and deaths in patient populations exposed to such low doses are highly speculative and should be discouraged. These predictions are harmful because they lead to sensationalistic articles in the public media that cause some patients and parents to refuse medical imaging procedures, placing them at substantial risk by not receiving the clinical benefits of the prescribed procedures."

It is also important to recognize that you benefited from the procedure. Even if the result of the imaging exam was negative, the physicians were provided information they could use to determine the next course of action. Refusing medical imaging procedures may result in real and substantial risk to the patient who does not receive the clinical benefits of the procedures.

Finally, let me add a note about dental x-ray exams. The average effective dose from an intraoral radiograph is 0.005 mSv (less than a day's worth of background radiation) and from a panoramic exam is 0.05 mSv.

Kent Lambert, CHP, FHPS

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 19 July 2017. 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.