People With Minor Injuries Are Increasingly Getting CT Scans

By Nancy Shute

Published January 19, 2016 at 1:43 PM EST

Neck strain might not feel like a CT-worthy injury to you, but it's increasingly getting advanced imaging.

If you fall off a curb, bop your head and go to the ER to make sure you're OK, there's a good chance you'll be trundled off for a CT scan.

That might sound comforting, but people with injuries minor enough that they get sent home are increasingly being given computed tomography scans, a study finds. That's despite efforts to reduce the unnecessary use of CTs, which use radiation and increase the lifetime risk of cancer.

There's been a lot of focus on excess use of CTs in children, but much less on adults who go to the emergency department for things that turn out to be no big deal.

So researchers at the University of California, San Francisco looked at data on every single emergency department visit in the state from 2005 through 2013. They looked at people who had relatively minor injuries, focusing only on those who were sent home after being evaluated and treated. That could include people with fractures, sprains and strains.

Out of those 8,535,831 people with injuries that didn't appear to be serious, 5.9 percent got at least one CT scan while they were in the emergency department. That number rose over time, from 3.51 percent in 2005 to 7.17 percent in 2013. The study was published Monday in the Journal of Surgical Research.

"There is a lot of awareness about overuse of CTs," says Renee Hsia, a professor of emergency medicine and health policy at UCSF who was the senior author of the study. But patients and doctors both have reasons for wanting a scan.

"Patients tend to want to be safe, which is not a bad thing," Hsia says, "but sometimes they want more rather than less. It's a very American thing. Also doctors don't want to miss anything."

But safety comes with a price. The 72 million CT scans that Americans got in 2007 will cause 29,000 excess cancers, according to a 2009 study from the National Cancer Institute. Nearly 15,000 of those cancers could be fatal.

Efforts to get doctors to cut back on use of CTs may have caused the little downward blip in Hsia's data from 2009 to 2011, but the numbers then continued to rise. CTs of the head were most popular. The pelvis and abdomen was the only body area that got scanned less often.

People who went to Level I and II trauma centers were more likely to get CTs, the authors found, which may reflect the culture of institutions used to dealing with severely injured patients.

As a practicing ED doctor, Hsia says there's a lot pressure to scan patients and get them out the door rather than keep them in the hospital overnight for observation, as they would have done in the past. "There's a lot of pressure for earlier and earlier diagnosis," she says. "And there are consequences."