Do DEXA Scans Have Radiation? Yes, About As Much as Eating 4 Bananas

Explore the safety of DEXA scans and the radiation levels involved in this diagnostic tool for measuring bone mineral density, muscle and lean mass, body fat, and more. Learn how DEXA scan radiation compares to everyday radiation exposure, the history of DEXA scans, and what studies show about their safety.

DEXA scans, or Dual-Energy X-ray Absorptiometry scans, are a widely-used diagnostic tool for measuring bone mineral density and assessing the risk of fractures. But do DEXA scans have radiation? And if so, how much? In this article, we'll explore the radiation levels of DEXA scans, how they compare to everyday radiation exposure, and what studies show about their safety.

The Science Behind DEXA Scans

DEXA scans use low-energy X-ray beams to create detailed images of bone density. The scanner emits two different energy levels, which are absorbed differently by bone and soft tissue. The ratio of absorbed energy helps to determine bone mineral density, which in turn can be used to diagnose conditions like osteoporosis and evaluate fracture risk.

Do DEXA Scans Have Radiation?

Yes, DEXA scans use a small amount of ionizing radiation to create images of the bones. Ionizing radiation is a type of energy that can remove tightly bound electrons from atoms, creating ions. This can potentially cause damage to cells and DNA, which is why there is concern about the safety of radiation exposure.

What Level of Radiation is in a DEXA Scan?

The radiation dose from a DEXA scan is relatively low compared to other medical imaging procedures like computed tomography (CT) scans. The effective dose for a DEXA scan ranges from 0.001 to 0.030 millisieverts (mSv), depending on the specific scan type and the body region being examined. To put this into context, the average annual background radiation dose that a person receives from natural sources is approximately 2 to 3 mSv.

How Does the Radiation in a DEXA Scan Compare to What We're Exposed to Every Day from Other Sources?

The radiation dose from a DEXA scan is lower than many other everyday sources of radiation exposure. For example, a transcontinental flight can expose passengers to approximately 0.03 to 0.05 mSv of radiation, and a dental X-ray can result in an exposure of about 0.005 mSv. The amount of radiation from a DEXA scan is generally considered to be safe for most patients, as the benefits of diagnosing and managing conditions like osteoporosis outweigh the potential risks associated with the small amount of radiation exposure.

What is the History of DEXA Scans?

DEXA scans were first developed in the 1980s as a more precise and accurate method for measuring bone mineral density compared to earlier techniques like single-photon absorptiometry (SPA) and dual-photon absorptiometry (DPA). The technology has since evolved, becoming more efficient and offering better image quality, making DEXA scans the gold standard for bone density measurement and fracture risk assessment.

What Do Studies Show About the Safety of DEXA Scans?

Research has shown that the low radiation dose associated with DEXA scans poses minimal risk to patients. A study published in the journal Radiology in 2014 found that the risk of developing cancer from a DEXA scan was less than one in a million for both men and women. The benefits of accurate diagnosis and effective management of bone health far outweigh the potential risks associated with radiation exposure from DEXA scans.

Article Highlights

• DEXA scans use a small amount of ionizing radiation to measure bone mineral density.
• The radiation dose from a DEXA scan ranges from 0.001 to 0.030 mSv, depending on the scan type and body region.
• Radiation exposure from DEXA scans is lower than many everyday sources, such as dental X-rays.
• DEXA scans were first developed in the 1980s and have since become the gold standard for bone density measurement and fracture risk assessment.
• Studies have shown that the low radiation dose associated with DEXA scans poses minimal risk to patients, with the benefits outweighing the potential risks.

Citations:

National Osteoporosis Foundation. (n.d.). What is a Bone Density Test? Link to article.

RadiologyInfo.org. (2021, March 31). Bone Densitometry (DEXA, DXA). Link to article.

American College of Radiology. (2021). ACR-SPR Practice Parameter for the Performance of Dual-Energy X-Ray Absorptiometry (DXA). [Link to article.] (https://www.acr.org/-/media/ACR/Files/Practice-Parameters/DXA.pdf)

World Health Organization. (2021). Radiation and Health. Link to article.

National Council on Radiation Protection and Measurements. (2009). Ionizing Radiation Exposure of the Population of the United States. NCRP Report No. 160. Link to article.

Blake, G. M., & Fogelman, I. (2007). The role of DXA bone density scans in the diagnosis and treatment of osteoporosis. Postgraduate Medical Journal, 83(982), 509–517. Link to article.

Smith-Bindman, R., Kwan, M. L., & Miglioretti, D. L. (2014). Who gets to decide? The need for informed consent in medical imaging. Radiology, 271(1), 11–13. Link to article.