Health professionals agree that some radiation scans are unnecessary, and potentially harmful, but there is considerable debate over what needs to be done to protect patients.

The discussion played out in Thursday’s New England Journal of Medicine, where one health expert called for the U.S. Food and Drug Administration to strengthen regulations, and two others rejected the notion, saying it would stifle future innovations in diagnostic technology.

Health professionals and policymakers have become increasingly concerned about scans’ health effects, as well the costs of such tests. According to the FDA, Americans’ exposure to radiation has nearly doubled over the last two decades. One CT scan of the chest emits 100 times the radiation of an X-ray, and an abdominal CT scan is equivalent to 400 chest X-rays.

Image quality is directly associated with radiation dose: the higher the radiation, the better the image. But patients may be paying a price for these high-quality scans, with recent reports claiming medical imaging may cause 29,000 new cancers a year.

There is little preventing physicians from using expensive high-quality scans when they don’t need to, Dr. Rebecca Smith-Bindman wrote in the NEJM.  No professional or governmental organization collects, monitors or reports CT scans, and there are no formal guidelines dictating appropriate radiation doses. The FDA approves CT scanners but does not oversee their use.

As a result, doctors’ and radiologists’ imaging practices are driven by personal preferences as well as financial interests. Patients sometimes demand certain medical tests from their doctors, based on reports from the media, the Internet or direct-to-consumer marketing. But some doctors who own testing labs or equipment will also refer a patient for tests, knowing they stand to financially benefit, directly collecting the fees charged for the scans.

“Following the precedent of the Mammography Quality Standards Act of 1992, which is widely believed to have improved the quality of mammography, Congress could grant the FDA jurisdiction over CT and other procedures that deliver radiation,” Smith-Bindman wrote.

While Smith-Bindman pushed for federal regulations to standardize radiation dosages, NEJM commentators Bruce J. Hillman and Jeff C. Goldsmith said that solutions are best left to the medical community, with a few legal reforms on the side.

“There already is a strong regulatory bias against imaging,” Hillman told the Associated Press. “If this becomes much worse, things will become so draconian there will no longer be an investment in innovation.”

Hillman and Golfsmith criticized medical schools for encouraging students to confirm their diagnoses using expensive imaging; scanning does not always lead to better diagnoses, they said. In addition, doctors tend to over-scan in order to protect themselves from potential lawsuits and tort reform could go a long way in discouraging such litigation, they said.