Tuesday, April 16, 2013

Guidance for Choosing Wisely in diagnostic imaging

- Kenny Lin, MD

Many of the primary care-relevant recommendations in the Choosing Wisely campaign advise physicians to think twice before reflexively ordering diagnostic imaging tests in certain clinical situations. Inappropriate imaging increases radiation exposure, leads to overdiagnosis and detection of incidentalomas, and increases costs for patients and health systems. In addition, as Drs. Brian Crownover and Jennifer Bepko observe in the April 1st issue of AFP, increasing radiation exposure is likely to lead to higher rates of cancer diagnoses and deaths:

In 2006, 380 million radiologic procedures (including 67 million computed tomography [CT] scans) and 18 million nuclear medicine procedures were performed in the United States. To highlight the disproportionate use, U.S. patients received approximately one-half of all nuclear medicine procedures worldwide while making up only 4.6 percent of the global population. The volume represents a sixfold increase (from 0.5 to 3.0 mSv [millisieverts]) in annual per capita radiation exposure from 1980 to 2006. ... Increasing recognition of future cancer risk from radiation exposure was illustrated in a 2009 study showing that 2 percent of all future cancer cases will likely come from previous CT exposure, resulting in approximately 15,000 deaths annually.

This article on the appropriate and safe use of diagnostic imaging goes on to review consensus indications for imaging in the central nervous system, chest, abdomen, and lumbar spine based on American College of Radiology appropriateness criteria. It includes a helpful Table on the average effective radiation doses of medical imaging procedures that clinicians may use to weigh the harm versus the potential benefit of a particular diagnostic imaging test. In general, the authors recommend discouraging patients from undergoing whole body scanning, which is associated with numerous health risks and no proven benefits.