A study of imaging utilization in the emergency department (ED) of Brigham and Women’s Hospital in Boston has shown that after more than a decade of increasing use, overall imaging relative value units (RVUs) decreased significantly between 2007 and 2012.

“This decrease in imaging is even more significant because it occurred in the context of either stability or an increase in the severity of illness in the ED patient population,” wrote study authors Ali S. Raja, MD, of the Center for Evidence-Based Imaging at Brigham and Women’s, and colleagues.

Findings were published in the August issue of American Journal of Roentgenology.

Raja and colleagues reviewed radiology utilization at their institution’s ED from Jan. 1, 1993, through Dec. 31, 2012. Over this time, the number of ED patient visits increased from approximately 48,000 to 61,000.

The ebb and flow of utilization mirrored other utilization studies which have shown overall imaging use in the U.S. growing until the mid-to-late 2000s, before plateauing and declining. In the current study, CT RVUs increased 493 percent between 1993 and 2007, while MRI RVUs increased 2,475 percent. At that point, CT and MRI saw declines of 33.4 percent and 20.6 percent, respectively, to 2012.

Sonography RVUs increased 75.7 percent over the entire study period while radiography saw a drop of 28.1 percent.

“Additional studies are needed to determine the causes of this decline, which may include quality improvement activities, advocacy for appropriateness by leadership, concerns regarding radiation exposure and cost, and health information technology interventions,” wrote Raja and colleagues.