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Medical Imaging Rates Continue to Rise Despite Push to Reduce Their Use

Potential Harms Need to be Considered before Scanning, Researchers Conclude

By Elizabeth Fernandez | UCSF.edu | September 3, 2019

Medical Imaging Rates Continue to Rise Despite Push to Reduce Their Use

Radiologic technologists check the equipment functions of a new Hybrid OR imaging system on the Parnassus campus. Photo by Susan Merrell.

Despite a broad campaign among physician groups to reduce the amount of imaging in medicine, the rates of use of CT, MRI and other scans have continued to increase in both the U.S. and Ontario, Canada, according to a new study of more than 135 million imaging exams conducted by researchers at UC Davis, UC San Francisco and Kaiser Permanente. This concerns researchers because medical imaging is widely believed to be overused.

The study, published Sept. 3, 2019, in the Journal of the American Medical Association, is the first of its size to determine imaging rates across different populations. It found that although the growth in imaging slowed in the early 2000s, it ticked back up in recent years for computerized tomography (CT) and magnetic resonance imaging (MRI) in most patient age groups. A notable exception was a decline in CT use in children in recent years.  

CT scans use ionizing radiation to create images of the inside of the body, and they deliver a radiation dose far higher than a conventional X-ray, while MRIs use magnetic fields and radio waves to create images and do not expose patients to ionizing radiation. The authors noted that the study does not discuss whether the documented imaging use was appropriate or associated with better patient outcomes.

Rebecca Smith-Bindman portrait.
Rebecca Smith-Bindman, MD, lead author of the study that reviewed imaging trends in U.S. and Canada. Photo by Susan Merrell

“Medical imaging is an important part of health care and contributes to accurate disease diagnosis and treatment, but it also can lead to patient harms such as incidental findings, overdiagnosis, anxiety and radiation exposure that is associated with an increased risk of cancer,” said lead author Rebecca Smith-Bindman, MD, a UCSF professor of radiology, epidemiology and biostatistics, and obstetrics and reproductive medicine.

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