Answer to Question #11846 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

A pediatric orthopedic surgeon recommended an x ray to check the leg of my five-month-old son. Although I clearly stated I did not feel comfortable with an x ray due to his young age and preferred an ultrasound, the doctor told me an x ray was best and the benefits outweighed the risks. Furthermore, he reassured me the x ray was of very little health risk. I reluctantly agreed.

My infant son did not have any findings on the x ray and his legs are perfectly fine; however, I have been worrying myself sick over this x ray. They performed an x ray from the hips down to his toes, and to my surprise, they did not cover his gonads, as they said a shield may obscure the image. It was one tabletop x ray on a pediatric x-ray machine in a pediatric clinic. When I called to ask the dosage of radiation received, no one at the practice could give me an answer. They dismissed my concern and said he received "very little" or "scant" amounts. A young woman who was holding my son's legs during the x ray was not wearing protective gloves when the x-ray beam penetrated her hands, which further concerns me about this practice's seemingly cavalier attitude to radiation exposure.

Do I need to be concerned about future health problems since my infant son's gonads were not protected with a shield? In general, what dosage of radiation do you suspect he was exposed to?

A

Please stop worrying about your son's radiation exposure; you did the right thing. 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 computed tomography (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 are of less risk than their alternatives, such as exploratory surgery.

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 because you won’t receive the clinical benefits of the procedures.

Earlier this year I was on a jury deciding a malpractice case. I learned all about referred pain, which is pain in one location caused by injury to another. In this malpractice case, the patient was an adolescent male who complained of knee pain; however, ultimately the injury was to the hip (slipped capital femoral epiphysis, SCFE, pronounced "skiffy"). Concern about referred pain very well may be why the orthopedic surgeon wanted an x ray of the entire leg.

At radiation doses above 100 millisieverts (mSv) there is clear and convincing evidence of health effects. However, health risks for radiation doses below 100 mSv are statistically equal to zero; in other words, they are too small to be seen or are nonexistent. Any prediction of risk from radiation exposures below 100 mSv is hypothetical and cannot be supported by scientific evidence. The Society's position statement "Radiation Risk in Perspective" explains in more detail health risks from low-dose radiation. Some risk information is also available from www.radiationanswers.org.

While I cannot determine your son's effective dose, I can say with certainty that it would be a small fraction of 1 mSv. A. Brindhaban and C.U. Eze reported in Medical Principles and Practices a range of doses to newborn infants and one-year-olds for several examinations. For pelvic exams in newborns (the exam most comparable to the exam your son received), the reported dose ranged from 0.016–0.156 mSv, and for one-year-olds, the reported dose range was 0.012–0.038 mSv. The exam performed on your son would deliver less dose than a pelvic exam.

Kent Lambert, CHP

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.
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