Who collects professional fees for neuroradiology interpretation, radiologists or nonradiologists?

Purpose: An increasing portion of imaging studies are performed by nonradiologists, especially for modalities with the highest relative value units. The aim of this study was to examine the trends in neuroradiologic interpretation among radiologists, neurologists, neurosurgeons, and other specialists within the Medicare population. Methods: The number of neuroradiologic studies interpreted by radiologists, neurologists, neurosurgeons, and other specialists in the inpatient, hospital outpatient, and private office settings was determined from the CMS Physician/Supplier Procedure Summary Master Files for 1996 to 2010. Studies billed through professional and global charges were aggregated. Utilization rates and utilization rate compound annual growth rates were computed by specialty and by imaging study. Results: In 1996, radiologists interpreted 4,802,490 (93.7%) CMS neuroradiologic procedures, neurologists 77,312 (1.5%), neurosurgeons 9,825 (0.19%), and other specialists 234,423 (4.6%). In 2010, radiologists interpreted 11,476,376 (93.5%) procedures, neurologists 101,172 (0.8%), neurosurgeons 20,697 (0.17%), and other specialists 680,786 (5.5%). Neurology and neurosurgery lost market share at all sites. Radiology's share increased in the inpatient (from 94.8% to 98.7%) and hospital outpatient (from 95% to 98.7%) settings but decreased in the private office setting (from 88.2% to 73.1%). Lost market share was captured by the other CMS specialty categories, including independent diagnostic testing facilities and multidisciplinary groups, many of which included radiologists. Conclusions: There was marked growth (140%) in neuroradiologic studies between 1996 and 2010 in the Medicare patient population. Radiologists' share of the total neuroradiologic interpretations remained unchanged and constituted 93.5% in 2010. Radiology's market share has shown growth in the inpatient and hospital outpatient sectors but not the private office sector, where independent diagnostic testing facilities, multidisciplinary groups, and other specialists have seen increases.