Chest imaging down despite increasing utilization of CT, CTA

Orders for Medicare-covered chest x-rays have dropped at a faster clip than those for chest CT and CT angiography (CTA) have risen in recent years, leading to a net decrease in overall noncardiac thoracic imaging. Meanwhile, radiologists’ role as the main providers of such imaging continues to help keep self-referral at bay.

These findings were published online Dec. 4 in the Journal of the American College of Radiology

Sarah Kamel, MD, of Thomas Jefferson University and colleagues reviewed Medicare Part B databases spanning from 2002 through 2014. They looked at all CPT codes having to do with noninterventional imaging of the thorax, grouping them into seven categories: x-ray, CT, CTA, noncardiac nuclear scans, MRI, MR angiography (MRA) and ultrasound.

The team found total utilization of all chest imaging peaked at 1,090 exams per 1,000 enrollees in 2005. From there it tumbled each year, to 913 per 1,000 in 2014 (a drop of 16 percent).

In addition:

• Chest x-ray utilization reached a high of 976 exams per 1,000 enrollees in 2005, then fell 19 percent to 790 per 1,000 in 2014.
• Chest CT rose sharply over the 2002-14 time window, peaking at 100 exams per 1,000 enrollees in 2007 before leveling off to around 90 in subsequent years.
• CTA utilization increased steadily, growing from just 2 per 1,000 in 2002 to 23 in 2014.

The authors further noted a steady decrease in nuclear chest imaging after 2002—and an increase, from 87 percent in 2002 to 91 percent in 2014, in radiologists’ share of thoracic imaging.

In 2002, nonradiologists’ share of this imaging was 9 percent, most of it in the form of chest x-ray. By 2014, their share had dropped to just 5 percent.

Kamel and colleagues posit as a probable explanation the low reimbursement rates for chest x-ray.

“The fact that self-referral has been kept to a minimum may be an important reason why utilization has remained under control for the past two decades,” they write. “This is a favorable development from the perspective of the healthcare system, although some concern might be raised about the increasing use of more costly modalities like CT and CTA.”