Answer to Question #11245 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

Why isn't the head normally covered during an x ray with some sort of lead protection? Why is there only thyroid, abdominal, and gonad lead protection?

A

The short answer is that the cells of the thyroid, abdomen, and gonads are more sensitive to the effects of x rays, and exposure of these cells and organs is more likely to increase the risk of developing cancer later. Lead protective shields are used for patients and staff to reduce the risk from the radiation that is scattered from the anatomical areas being imaged. The brain is much less sensitive to radiation so exposure to the head is not very likely to cause cancer.

For patients, shielding is most often used for sensitive parts of the body that are close to, but not in, the part that is being imaged. When the lead protection is in the x-ray field, it can hide what the physician needs to see and lead to additional x rays being needed. When the head is not being imaged, it receives a very small amount of scattered radiation from the x ray. In the majority of cases, the use of lead shielding on the head would be uncomfortable and have little or no benefit.  

Deirdre H. Elder, MS, CHP, CMLSO

References

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 25 August 2015. 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.