(HealthDay News) — From 1996 to 2010 there was an increase in the use of advanced diagnostic imaging and associated radiation exposure within integrated health care systems, according to a study published in the June 13 issue of the Journal of the American Medical Association.
To estimate trends in imaging utilization and associated radiation exposure, Rebecca Smith-Bindman, M.D., from the University of California in San Francisco, and colleagues retrospectively analyzed electronic medical records for one to two million member-patients of six large integrated health systems across the United States each year.
The researchers found that, over the study period, enrollees underwent a total of 30.9 million imaging examinations (1.18 tests per person per year). Advanced diagnostic imaging, including computed tomography (CT), magnetic resonance imaging (MRI), nuclear medicine, and ultrasound, accounted for 35 percent of the examinations. From 1996 to 2010, the use of advanced diagnostic imaging increased, with annual increases of 7.8, 10, and 3.9 percent, respectively, for CT, MRI, and ultrasound. Use of nuclear medicine decreased 3 percent annually, but there was a 57 percent annual growth rate in positron emission tomography after 2004. Increased use of CT over the study period correlated with an increase in radiation exposure, with a doubling of the mean per capita effective dose and the proportion of patients exposed to high or very-high radiation annually. By 2010, 6.8 and 3.9 percent of those who underwent imaging received high and very-high annual radiation exposure, respectively.
“The increase in use of advanced diagnostic imaging has almost certainly contributed to both improved patient care processes and outcomes, but there are remarkably few data to quantify the benefits of imaging,” the authors write.