Answer to Question #13310 Submitted to "Ask the Experts"

Category: Medical and Dental Equipment/Shielding — Shielding

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

Q

Recently, my son, who is now four months of age, had three x rays taken of his skull. For the first two, the radiation technician who was performing them, as well as myself, totally forgot about the lead shielding that was supposed to be put over his pelvis.

So, I was wondering, is this negligible? Or do you predict that there could have been a large dose of radiation administered enough to worry about? 

A

You can put you mind at ease regarding your concern. In fact, it is very interesting that you asked this question because over the past year this entire issue has been reviewed by a number of professional organizations including the American Association of Physicists in Medicine (AAPM), the American College of Radiology (ACR), the Health Physics Society, et.al.

On 2 April 2019, the AAPM published a Position Statement on the Use of Patient Gonadal and Fetal Shielding. Endorsements from other professional organizations can be reviewed at the bottom of the AAPM position statement.

In addition, I have personally taken "scatter" measurements (i.e., measurements a few inches outside the area being x rayed) and found that the radiation levels just a couple of inches away from the primary area are significantly lower and of little concern. In fact, most of the radiation levels outside the primary area being imaged result from what is referred to as "internal scatter" which is essentially x rays bouncing around inside the body and those levels also tend to be very low a few inches away from the primary area being imaged. These points are mentioned in the AAPM position statement.

As indicated above, the use of lead shielding of the pelvis is not necessary and does nothing to reduce the exposure to those areas from x rays of other parts of the body. Since this is a practice that has been carried out for such a long time and, in fact, may appear as a requirement in some regulations, it may take some time for everyone to become comfortable with the idea of foregoing the use of the lead shields. I hope this information will ease your mind.

Mack L. Richard, MS, 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.
Answer posted on 10 February 2020. 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.