Understanding X-rays

Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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• Are X-rays Safe?
• Radiation Versus Radioactive
• Diagnostic X-rays Do Not Increase the Risk of Cancer
• Recommendations
• Synonyms and Keywords
• Authors and Editors
• References
• Read more on Understanding X-rays from Healthwise

Are X-rays Safe?

The use of X-rays allows physicians to look inside the body to diagnosis an injury or illness. When done for appropriate situations, X-rays are safe and beneficial. It is important that X-rays are not misused or overused because over a lifetime, a person may be exposed to a fairly large amount of cumulative radiation, and it is important than the benefit of each X-ray test be considered before it is done.

Radiologic technologists are trained to use the least amount of radiation possible to produce an image that will help with diagnosis. The technologist or the radiologist (the physician who supervises the testing and then interprets the X-ray images) is often able to tell the patient how much radiation is being used.

If you ask, and are told a dose of radiation, you may not understand what a dose of 1 millisievert (mSv) might mean. But if this effective dose is converted into the amount of time it would take you to accumulate the same effective dose from background radiation, you could make a comparison. For example, the average background rate of radiation you are exposed to from the environment just by living in the United States is about 3 mSv per year. So a mammogram with a dosage of 1 mSv would translate into the amount of radiation you would get by just living in the U.S. about four months.

This method of explaining radiation is called Background Equivalent Radiation Time or BERT. The idea is to convert the effective dose from the exposure to the time in days, weeks, months, or years it would take to obtain the same effective dose from background radiation. This method has also been recommended by the United States National Council for Radiation Protection and Measurement (NCRP).

However, radiation doses may accumulate quickly, depending upon the situation. A trauma victim who is critically injured may be exposed to 30 mSv during treatment. To put this in perspective, a Hiroshima survivor may have been exposed to 50-150 mSv of radiation.