CT scans, a major driver of medical radiation exposure, increased from 67 million to 84 million scans over the 10-year period. However, the average individual effective dose from CT procedures dropped by 6%, thanks to several factors, according to study co-author Mahadevappa Mahesh, M.S., Ph.D., professor of radiology and cardiology at Johns Hopkins University School of Medicine in Baltimore.

"One important factor is the dose modulation techniques available on most CT scanners in the country," he said. "The second factor is that overall CT detectors are becoming very efficient in the sense that they can utilize less radiation to create the same quality images."


Dr. Mahesh also credited campaigns such as Image Wisely, a joint effort of the Radiological Society of North America, the American College of Radiology, American Society of Radiologic Technologists and American Association of Physicists in Medicine, aimed at optimizing dose and reducing unnecessary imaging examinations in the adult population, and Image Gently, which does the same in the pediatric population. He also pointed to accreditation requirements that are contributing towards dose stabilization.

Now that U.S. medical radiation exposure levels appear to have stabilized, the researchers stressed the importance of sustained vigilance to keep the trend from reversing.

"We don't want people to become complacent," Dr. Mahesh said. "Things are generally going in a good direction, but we need to continue on that path."

Dr. Mahesh and colleagues plan to publish a report next year on trends in medical radiation exposure worldwide.


"Patient Exposure from Radiologic and Nuclear Medicine Procedures in the United States: Procedure Volume and Effective Dose for the Period 2006-2016." Collaborating with Drs. Mettler and Mahesh were Mythreyi Bhargavan-Chatfield, Ph.D., Charles E. Chambers, M.D., Jennifer G. Elee, B.S., Donald P. Frush, M.D., Donald L. Miller, M.D., Henry D. Royal, M.D., Michael T. Milano, M.D., David C. Spelic, Ph.D., Armin J. Ansari, Ph.D., Wesley E. Bolch, Ph.D., Gary M. Guebert, D.C., Robert H. Sherrier, M.D., James M. Smith, Ph.D., and Richard J. Vetter, Ph.D.

Radiology is edited by David A. Bluemke, M.D., Ph.D., University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, and owned and published by the Radiological Society of North America, Inc.


About RSNA
RSNA is an association of radiologists, radiation oncologists, medical physicists and related scientists promoting excellence in patient care and health care delivery through education, research and technologic innovation. The Society is based in Oak Brook, Illinois.

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