October 11, 2010

Dramatic rise in MRI and CT use in ERs raises questions

A dramatic increase in the use of medical imaging in emergency departments when seeing patients with injuries hasn’t paid off with an equal rise in diagnosing life-threatening conditions or follow-up hospital admissions, a team of Johns Hopkins researchers concludes in a study published in the Oct. 6 issue of the Journal of the American Medical Association.

The research group, led by Frederick Kofi Korley, an emergency physician and assistant professor in the Johns Hopkins School of Medicine, reviewed emergency department data collected nationally over a 10-year period, 1998 to 2007. The Johns Hopkins team found that patients with injury-related conditions were three times more likely to get a computerized tomography or magnetic resonance imaging scan in 2007 than they were in 1998.

During the same 10-year period, the Johns Hopkins team found that diagnosis of life-threatening conditions, such as a cervical spine fracture or liver laceration, rose only slightly. There was virtually no change in the proportion of hospital admissions for patients seen in emergency departments for injury-related conditions in the same time span.

Korley and Johns Hopkins colleagues Thomas D. Kirsch, an associate professor in Emergency Medicine, and Julius Cuong Pham, an assistant professor in Anesthesiology and Critical Care Medicine, analyzed the data.

They said that studying the trend is important because increased medical imaging contributes to radiation exposure and may lead to higher health care costs.

“The carcinogenic effects of exposure to CT are especially important in patients presenting with injury-related conditions because they tend to be younger and receive multiple CTs,” the authors write in their study.

The authors also note that an indirect effect of increased use of CT is “increased length of visit in the emergency departments due to the long waiting period for imaging results. This can contribute to emergency department crowding and can increase the risk of medical error.”

The Johns Hopkins researchers write that many factors may have contributed to the spike in the use of CT and MRI scans in U.S. emergency departments.

“Some factors that may have contributed to this significant increase in CT use are the superiority of CT scans over X-rays for diagnosing conditions such as cervical spine fractures, the routine use of whole-body scanning for patients treated in some trauma centers, the increased availability of CT scanners, the proximity of CT scanners to the patient care areas of most emergency departments, the speed of new-generation CT scanners leading to a decrease in the need to sedate pediatric patients and concern about malpractice lawsuits for a missed diagnosis,” the authors write.

The team recommends that additional study be undertaken on the issue to better understand the reasons for this increase and to provide guidance on how physicians can continue to provide excellent emergency care cost-effectively. “Further work is needed to understand the patient, hospital and physician factors responsible for this increase and to optimize the risk-benefit balance of advanced radiology use,” the authors conclude.