By Aine Cryts

Rebecca Smith-Bindman, MD, professor of radiology, epidemiology, and biostatistics at University of California, San Francisco, and her co-authors had one question they wanted to answer: Are medical imaging rates trending up or down?

It was clear that the use of CT, MRI, and ultrasound had increased rapidly from 2000 to 2006. The U.S. Government Accountability Office revealed in 2008 that between these years, Medicare spending on imaging services paid for under the Part B physician fee schedule had more than doubled; approximately 80% of the spending growth was related to the surge in the volume and complexity of imaging services.

That’s in addition to a 2012 study (where Smith-Bindman was the lead author) that showed a large increase in the rate of advanced diagnostic imaging and associated radiation exposure within integrated healthcare systems between 1996 and 2010.

But what had happened with imaging trends since then?

To answer that question, Smith-Bindman and her co-authors studied the rate of CT and MRI use from 2000 to 2016 in seven healthcare systems in the United States and one health system in Ontario, Canada. In a study published in September in the Journal of the American Medical Association, they show that CT and MRI use continued to rise during this time period, albeit at a slower pace than in recent years.

In addition, the researchers learned that imaging rates continued to increase for children—except for CT, which stabilized or declined in more recent periods. The study focused on the use of CT, MRI, ultrasound, and nuclear medicine imaging and included annual and relative imaging rates by modality and patient age.

Some highlights of their findings:

  • While annual growth in CT, MRI, and ultrasound were highest between 2000 and 2006, use of such imaging continues to increase year over year; there’s been 1% to 5% annual growth between 2012 and 2016 in this type of imaging for most age groups and most tests in the United States and Ontario.
  • CT use in children has declined in the United States between 2009 and 2013; in Ontario, CT use has remained stable since 2013 and has gone down since 2006.
  • CT and MRI rates are higher in the United States than in Ontario, although the gap is shrinking.

“I think there’s this widespread belief that imaging rates have come down,” Smith-Bindman tells AXIS Imaging News. “That’s really not the case.” Her take-away: “We’re using too many of these diagnostic tests. They’re super-helpful, but we’re using too many of them.”

That’s despite efforts, such as Choosing Wisely, an initiative of the American Board of Internal Medicine (ABIM) Foundation that seeks to drive conversations between patients and physicians about reducing unnecessary tests and treatments, laments Smith-Bindman.

So, what can radiologists do? They can help referring clinicians to use imaging more judiciously, Smith-Bindman tells AXIS. “Obviously, we don’t consult with every test or order. That would not really be possible. But we consult on a lot [of cases]. A lot of doctors call us and ask our advice.”

While she counsels against radiologists thinking of themselves as “gatekeepers where we’re reducing access to these tests,” radiologists can serve as educators, “where we help clinicians understand the best path forward,” says Smith-Bindman. “It might be imaging. It might be imaging with a test that’s less invasive than the one they’re planning. It might be a test that’s less expensive. Or the path forward might be not to image.”

Aine Cryts is a contributing writer for AXIS Imaging News.