The total utilization rate for all ultrasound-guided (US-guided) procedures doubled between 2004 and 2010, according to an analysis of claims data published online Sept. 26 in the Journal of the American College of Radiology.

While radiologists still perform the largest share of US-guided procedures, growth in usage among other specialists made 2010 the first year that nonradiologists performed more US-guided procedures than radiologists, explained Vijay M. Rao, MD, and colleagues from Thomas Jefferson University Hospital and Jefferson Medical College, Philadelphia.

The authors based their findings on data from the Center for Medicare & Medicaid Services Physician Supplier Procedure Summary Master Files for 2004 through 2010.

In 2004, the total utilization rate for all US-guided procedures was 2,425 per 100,000. This number jumped to 4,870 per 100,000 by 2010, thanks to a compound annual growth rate of 12.3 percent.

Nonradiologists as a group accounted for more than 72 percent of the volume growth over the study period and performed 922,672 US-guided procedures in 2010 compared with 794,497 performed by radiologists, according to Rao and colleagues.  

After radiologists, surgeons performed the second largest share of US-guided procedures, at 19.4 percent. Other providers who saw large volume increases from 2004 to 2010 were anesthesiologists, rheumatologists, midlevel providers, primary care physicians and nonrheumatologist internal medicine subspecialists.

Rao and colleagues wrote that their study was unable to clarify what was causing the rapid increase in nonradiologist use of US-guided procedures. “More research is needed to discern whether increases in utilization of [US-guided procedures] are the result of increased adoption of US guidance for procedures that would have been previously performed without US guidance or whether the increased utilization reflects a lower threshold among nonradiologists for performing these procedures because they had acquired US capabilities. The latter could raise concern for self-referral, depending on the clinical appropriateness of these procedures.”

They noted that volume growth was especially high in private offices, and that similar high utilization trends have been described following nonradiologist ownership of CT, MRI and PET equipment.

Joint aspirations, steroid injections and tissue biopsies were examples provided by the authors of procedures previously performed without US guidance that may now be done with imaging.

“For many patients, the addition of US guidance to procedures previously performed without imaging guidance may significantly improve the quality of care provided to these patients,” wrote the authors. “The efficient allocation of health care resources, patient safety, and health care quality all depend on these procedures being performed for the appropriate clinical indications and by individuals with appropriate training.”