The researches find that 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 believe to be overuse.
Amount of imaging in medicine
The study, published September 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.
MRIs use magnetic fields
“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, over diagnosis; anxiety and radiation exposure that is associate 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.
Although it is widely believe that imaging rates are declining due to payment and educational efforts that have targeted unnecessary imaging, the authors found a reacceleration in imaging use; with ongoing growth in the use of CT and MRI in adults. “Like all aspects of medicine; it’s important to make sure imaging is justify, and that the potential benefits are balance against the potential harms;” said Smith-Bindman, a member of the Philip R. Lee Institute of Health Policy Studies.
“These potential harms of false positive diagnoses and over diagnoses can impact everyone who undergoes a test and thus need to be considered when imaging is used.” “The good news is that rates of CT imaging are starting to come down in children;” said Miglioretti, who is also a senior investigator with Kaiser Permanente Washington Health Research Institute. “However, they’re still far lower in Ontario than in the U.S., suggesting there is additional room for improvement. It’s also important to reduce unnecessary imaging in adults given they are also at risk of radiation-induce cancers.”