Why we can ditch the apron: A radiology professor explains radiation protection

Stephen Graves, PhD

Since the 1950s, lead shielding has been used to protect patients from radiation used in many imaging procedures. This practice is no longer supported by major associations focused on radiation regulation. Our mission to provide the highest quality care to our patients requires a commitment to adaptability when that means patients can experience better outcomes and treatments.

Effective July 1, 2022, UI Health Care will no longer use lead shields as radiation shielding for fetal and gonad protection. Stephen Graves, PhD, an assistant professor in the department of radiology at Carver College of Medicine, helped explain why not making the switch means a greater health risk to patients.

Why will UI Health Care no longer require or recommend a lead apron for patients?

“Since the 1950s, two important things have happened with respect to our understanding of radiation protection. The first is that the radiation sensitivity of fetal and gonadal tissues is now known to be much lower than originally thought. The hereditary effects of radiation have in fact never been demonstrated in humans, even among relatively highly exposed populations such as atomic bomb survivors. And the second major thing that’s happened is that the radiation dose from imaging procedures has been reduced about 20 to 25 times since the 1950s. A chest X-ray, for example, now delivers a similar radiation dose to that one would receive from a transatlantic flight, or even just natural background radiation in about 10 days in the state of Iowa.

Why is UI Health Care changing this policy now?

“We are modifying our policy regarding fetal and gonadal protection in response to recent professional and radiation protection recommendations at national and international levels. These recommendations suggest that radiology practices should discontinue the use of fetal and gonadal shielding in routine diagnostic imaging procedures. And these recommendations are based on the fact that shielding has been shown to provide no or negligible benefit under ideal conditions and can in fact be detrimental in some situations.

What is the risk to a person’s health without shielding?

“The risk of negative health effects from diagnostic radiation is very, very low. And these imaging procedures are only performed in medical situations where the diagnostic information is important for the medical care of individuals. So, if an imaging procedure is necessary, the health risks are much greater if one does not receive this diagnostic care.

What if a patient is pregnant? Should they still wear a lead apron then?

“Shielding is not recommended for pregnant patients at this time, as radiation exposure to the fetus is very low for a number of imaging procedures. In addition, exposure is well below the thresholds for negative effects on the health of the mother or the fetus. In addition, the scattered radiation that reaches the fetus is mainly internal and an external lead apron is not very effective in preventing this. If the lead apron masks part of the body that the radiologist needs to see during this imaging procedure, the procedure may need to be repeated, resulting in even greater radiation exposure for the patient.

Is this change only for adults? What about x-rays for children?

“This change will affect both adults and children undergoing diagnostic imaging procedures.”

What is being done to limit the amount of radiation exposure?

“UI Health Care has some of the most advanced imaging technologies in the world, allowing us to perform imaging procedures with the lowest possible radiation dose. The detectors we use for imaging are now much more sensitive than before, meaning we can use less radiation to perform the procedure. We have advanced features like automated exposure control that customizes the amount of radiation to a patient’s individual anatomy, so you don’t give too much or too little in any particular case.

“Soon, the University of Iowa will be one of the first centers in the world to have a technology called Photon counting CT, which has the potential to further reduce radiation dose for imaging procedures. Additionally, our physicians use their best professional judgment to ensure that we perform these studies in patients who truly need them. And this is another important way to reduce unnecessary exposure.

Can lead shielding actually increase radiation exposure?

“Yes. In rare cases, lead shielding may interfere with a system’s automated exposure control, causing it to increase radiation dose during the examination procedure. This does not necessarily compromise the value of this particular diagnostic procedure, but in many patients this may have the opposite of what was intended with lead shielding Again, if the shielding is blocking a part of the body that the radiologist needs to see, the procedure may have to be repeated.

Can a patient request lead protection during their examination?

“If the patient is unwilling to undergo the diagnostic procedure without fetal or gonadal shielding, the technologist may use shielding in these circumstances. But this should only happen after an informed conversation between provider and patient about the risks and benefits of using this shielding.

Why will X-ray technologists and radiologists still wear a lead apron?

“Adequate protection for our technologists and other professional workers who work with and around X-ray technologies is still very important to reduce unnecessary exposure of these professional workers. Keep in mind that these people perform many procedures each year. They only experience minimal exposure for each procedure, but overall it is still important to keep exposure levels as low as reasonably possible. Lead aprons and thyroid shields are very effective at blocking scattered radiation, and they will remain useful tools for our team.

Is this likely to be common practice for healthcare organizations in Iowa?

“Many other healthcare organizations in the United States have implemented this change already based on consensus between health physics and radiation protection organizations. Other institutions will adopt these policies according to their capacity.

“We have a leading radiology technology training program in the state, and technologists who graduate from our program end up serving the health care needs of the entire state. And so, these changes will have an impact on our training and our curriculum for future graduates.

“Over time, state practices will likely follow our lead on this.”

Questions or concerns? Contact Stephen Graves at stephen-graves@uiowa.edu.

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