Vascular ultrasound (VUS) utilization in the Medicare population peaked in 2009 and has been in decline ever since, according to a recent study published by the Journal of the American College of Radiology.

Anand M. Prabhakar, MD, of the Massachusetts General Hospital department of radiology, and colleagues wrote that cardiovascular disease accounts for one-third of all deaths in the U.S., and VUS has become an important modality in its evaluation.

“Advantages of VUS include noninvasiveness, portability, avoidance of ionizing radiation, cost and price, as well as its ability to image dynamically (eg, to obtain real-time data about blood flow directionality),” the authors wrote.

Hoping to track VUS’ utilization over the last two decades, the authors studied Medicare Physician Supplier Procedure Summary Master Files data from 1998 to 2013 and Medicare enrollment data from 1998 to 2012.

They found that, overall, annual claims for VUS studies for Medicare beneficiaries jumped from more than 4.4 million in 1998 to more than 8.5 million in 2013, a total increase of 94.5 percent.

The authors also noted that there was a 4.5 percent compound annual growth rate (CAGR) for VUS examinations from 1998 to 2013. Looking at the various provider groups, radiology had a 4.2 percent CAGR, vascular surgery had a 7.8 percent CAGR, and cardiology had an 8.7 percent CAGR.

Viewing the VUS data per 1,000 beneficiaries, utilization jumped from 146 in 1998 to 264 in 2012. However, the numbers peaked at 270 in 2009 and began to gradually decline afterward.

“This comports with a variety of other studies demonstrating a decline in the utilization of advanced medical imaging,” the authors wrote. “That decline has been attributed in part to increased awareness of and concern for radiation exposure, but because ultrasound involves no ionizing radiation, other previously implicated drivers may play more of a role in the relative decline in imaging than previously believed. Some reasons include an emphasis on reduction of costs or the recent economic recession in 2009. In addition, the advent of utilization management tools such as clinical decision support and radiology benefit managers has been shown to contribute to the slowdown in imaging.”

In their final analysis, Prabhakar et al. added that in recent years, the maturity and development of certain technologies has led some medical services—including VUS—to move from a hospital setting to an outpatient office setting

“This has particularly affected medical imaging, as many services traditionally performed by radiologists have been increasingly performed by other specialists,” the authors wrote. “For example, endovascular maintenance procedures have shifted toward nephrology and surgery. We noted such shifts for carotid Doppler ultrasound and lower extremity arterial ultrasound but not for lower extremity venous ultrasound.”