Too Much Radiation?

That calculation is still controversial, and many doctors disagree with it, but most do subscribe to the goal of reducing radiation exposure. CT manufacturers and researchers have developed techniques to reduce radiation exposure per scan. One involves tailoring the X-ray dosage by taking into account a patient's size and thickness in different directions. There's also a trend toward low-radiation scans in some cases—the images may be a little fuzzier but supersharp pictures aren't always necessary to make a diagnosis.

Doctors are also being urged to pay special attention to the groups that are more likely to be harmed by radiation: younger people (whose growing tissues are more vulnerable) and people who get scanned many times. Dr. Aaron Sodickson and collaborators at Harvard-affiliated Brigham and Women's Hospital are developing a system that will keep track of the cumulative radiation exposure from CT scans and other imaging studies to identify patients at higher risk of radiation-induced cancer. The system will alert doctors of the risk when they order a CT scan of one of those patients.

Ultimately, the value of any tool lies in the wisdom of those who wield it. In 2009, researchers will be working hard to identify how best to reduce the radiation exposure from CT scans—and to identify those people who can most benefit from this powerful technology.

Wehrwein is the editor and Nagurney serves on the editorial board of the Harvard Health Letter. Nagurney is an emergency department doctor at Massachusetts General Hospital.

© 2008