Investigating a Decrease in CT Volume

Reductions in CTs at one academic medical center appear to indicate more conservative prescribing behavior, according to an article published in the Journal of the American College of Radiology.

Researchers from The Ohio State University in Columbus sought to determine the differences in radiation exposure from 2008 to 2012 among patients who received CT scans of the abdomen, head, sinus and lumbar spine after.

The data regarding CT scans performed on inpatients located primarily in the medical ICU and general medicine units were collected from an electronic database for the calendar years 2008 to 2012. The researchers calculated annual CT volume, rate, average effective dose, radiation exposure and estimated cancer risk.

Results showed a net decrease of 15 percent over five years for CT imaging of the four targeted body areas. The usage increased by 21 percent from 2008 to 2010, but then decreased by 30 percent from 2010 to 2012. “This same trend was seen individually for abdominal and pelvic imaging, which also increased from 2008 to 2010, then decreased from 2010 to 2012 for a 37 percent net decrease,” the authors wrote.

Other findings included a 30 percent to 52 percent reduction in radiation exposure to targeted body areas and a 63 percent reduced estimated rate of induced cancers.

Physicians may be reducing their imaging orders for different reasons, such as the increase in radiation concerns; knowledge of the associated test costs; the need for some commercial payors to pre-approve imaging tests; or the criteria published by the ACR and other organizations, such as Image Wisely. “In addition to these explanations, a change in the default order sets in the institution’s electronic health record reduced the number of imaging procedures automatically ordered for most clinical indications,” the authors noted.

The researchers concluded that at this one facility, exposure to ionizing radiation from these CT scans was reduced because fewer exams were performed and radiation doses were lower.