Council issues alert on rising x-ray exposure

Not just radiologists but everyone, including patients and referring physicians, needs education on the benefits and risks of radiation exposure from medical imaging studies. That was the conclusion in a nutshell of a memo sent by the National Council on Radiation Protection and Measurements to the imaging community.

Radiologists, physicists, nuclear medicine physicians, geneticists, and other radiation protection experts gathered in April near Washington, DC, for the council's 2007 meeting. Participants unveiled preliminary findings of an NCRP scientific committee study showing that the amount of radiation dose the U.S. population is receiving from clinical imaging may have increased more than 600% over the last two decades. The study also found that CT scanning, which accounts for about 10% of all imaging procedures, is responsible for almost half of the total estimated effective dose.

"It's no longer sufficient to restrict radiation safety education to radiologists alone," said coauthor Mythreyi Bhargavan, Ph.D., director of research for the American College of Radiology.

Bhargavan also supplied the NCRP with an analysis on imaging utilization trends based on data from public and private sources, including Medicare, the VA, IMV, and Blue Cross Blue Shield. Some trends were evident:

• The number of imaging procedures and locations providing imaging exams increased 34% and 38%, respectively, between 2001 and 2006.

• The volume of CT studies has been growing at a rate greater than 10% per year since 2001.

• The total volume of imaging procedures performed during the same period went up much more rapidly at nonradiology, nonhospital settings compared with inpatient, radiology settings.

Hospitals have the staff and guidelines required to manage imaging equipment and radiation safety that outpatient office settings generally lack. This discrepancy indicates where education efforts should start, but everybody needs a reminder, Bhargavan said.

Radiologists learn the ropes during residency, but they may neglect to calculate doses once in practice. Medical students need to learn what they are subjecting their patients to. Emergency physicians, though under a great deal of pressure, must be aware of the dose factor and contemplate alternative imaging procedures. Referring physicians need to be aware of what they are prescribing to their patients. And patients should understand the risks versus the benefits of an imaging exam before they either demand or fear having one, she said.