Utilization Trends in Noncardiac Thoracic Imaging, 2002-2014.

PURPOSE: To analyze recent trends in utilization of the various noncardiac thoracic imaging modalities in the Medicare population.

METHODS: The Medicare Part B databases for 2002 through 2014 were reviewed. All CPT codes pertaining to noninvasive imaging of the thorax were selected and grouped into seven categories: x-ray, CT, computed tomographic angiography (CTA), nuclear scans (noncardiac), MRI, MR angiography, and ultrasound. Yearly utilization rates per 1,000 Medicare beneficiaries were calculated. Medicare physician specialty codes were used to determine how many studies were performed by radiologists versus nonradiologist physicians.

RESULTS: The total utilization rate of all chest imaging peaked at 1,090 per 1,000 in 2005, then progressively declined to 913 by 2014 (-16%). In 2002, radiologists' share of thoracic imaging was 87% and increased to 91% by 2014. Among all providers, the total utilization rate of chest CT rose sharply, peaked at 100 in 2007, and has remained steady at around 89-91 in more recent years. The CTA utilization rate rose progressively from 2 in 2002 to 23 in 2014. Utilization rates of nuclear chest imaging decreased steadily after 2002. Chest x-ray rates reached a peak of 976 in 2005 but then declined to 790 in 2014; this change was largely responsible for the decline in total thoracic imaging.

CONCLUSION: Overall thoracic imaging utilization rates have declined in recent years, despite an increase in use of CT and CTA. The decline largely resulted from a decrease in use of chest x-rays.