Utilization rates of neuroradiology across neuroscience specialties in the private office setting: who owns or leases the scanners on which studies are performed?

Background and Purpose: Recent literature shows an increasing portion of imaging studies being conducted and interpreted by nonradiologists, especially across the modalities with the highest RVUs. We examined the trends in the Medicare technical charges for private office neuroradiology studies submitted by subspecialists to identify utilization trends among MR and CT scanner owners or lessees over the last decade.
Materials and Methods: The number of neuroradiology studies performed on MR and CT machines owned or leased in private offices was determined from the CMS PSPSMF for 1998-2008. Studies billed through technical and global charges were aggregated. Utilization rates and utilization rate CAGRs were computed by specialty and by imaging study.
Results: Between 1998 and 2008, MR studies grew by a factor of 2.5 and CT studies grew by 2.1. In 2008, radiologists charged the technical/global fee in 1,386,669 (56.6%), neurologists in 82,360 (3.4%), neurosurgeons in 29,218 (1.2%), multi/IDTF in 617,933 (25.2%), and other specialists in 334,843 (13.7%) of neuroradiology cases. Changes from the 1998 base rate to the 2008 rate per 1000 Medicare beneficiaries were 24.1 to 39.7 for radiologists, 1.03 to 2.4 for neurologists, 0.15 to 0.84 for neurosurgeons, 2.2 to 17.7 for multi/IDTF, and 1.3 to 9.6 for other specialists. All specialties, except for multi/IDTF, showed greater MR utilization increases than CT. Neurology (CAGR of 10.6%), neurosurgery (22.1%), multi/IDTF (23.2%), and other specialists' (24.6%) MR growth outpaced that of radiology's (5.3%).
Conclusions: All nonradiologists showed greater overall utilization growth in private office neuroradiology than did radiology. Also, nonradiologists generally showed greater utilization increases in MR than CT. Radiologists' private office neuroradiology technical fee share shrank from 83.6% to 56.6% between 1998 and 2008.