RODALE NEWS, EMMAUS, PA—Advanced medical imaging tools such as computed tomography (a.k.a. CT, or sometimes CAT, scans) allow doctors to see what’s happening inside the body without actually opening it up. Which is undoubtedly a good thing, as it’s pretty much eliminated the concept of exploratory surgery. But a new report suggests that the resulting dramatic uptick in potentially unnecessary imaging procedures could be exposing us to unhealthy amounts of radiation.
THE DETAILS: The National Council on Radiation Protection and Measurements (NCRP) recently announced that Americans were exposed to more than seven times as much radiation from medical procedures in 2006 as they were in the early ’80s, largely due to a dramatic bump in CT and nuclear medicine (the branch of medicine and medical imaging that uses radioactive isotopes in the diagnosis of disease). Kenneth R. Kase, MD, senior vice president of the NCRP, reported: “These two imaging modalities alone contributed to 36 percent of the total radiation exposure [which includes background exposure from natural radiation in soil, rocks, and space], and 75 percent of the medical radiation exposure, of the U.S. population.” Since the dose of radiation used in most exams is very low, the medical benefit of the exam can outweigh the potential risk from the radiation. But radiation in any dosage can damage cells in the body, and so comes with some risk of triggering a health problem. With the surge in CTs, scientists are just now attempting to get a better sense of how much risk all these scans represent.
WHAT IT MEANS: The American College of Radiology (ACR) sees two trends at work here:
1: The vast improvement in imaging quality. Take the CT, which was developed in the early 1970s. For the first 25 years of scanning, the test could only make one image at a time. Today, radiologists can make up to 320 images simultaneously. When the resolution and the ability to image vascular structures vastly improved around 2000, the number of CTs skyrocketed.
2: The rise in “self-referrals,” or nonradiologists buying imaging equipment and prescribing in-office scans for their own patients. Radiologists typically get patient referrals from other physicians—they don’t order the scans themselves—so they can’t inflate the number of scans they perform. Nonradiologists who refer their patients to their own scanners for testing (and profit), can—and do, studies have proved. “We know from studies that when there’s financially motivated self-referral, the amount of imaging is, on average, twice as high as when there’s no financial incentive,” says James H. Thrall, MD, chair of the American College of Radiology.
Here’s how to make smart decisions about medical imaging tests:
Published on: March 23, 2009