Purpose: To study growth trends in the ownership of magnetic resonance imaging (MRI) examinations by nonradiologist physicians who either own the equipment outright or are involved in scan leasing arrangements.
Methods and materials: Medicare Part B data sets from 2000 through 2005 were reviewed, and procedure codes for MRI examinations were selected. The focus was on only those procedures performed at nonhospital, private-office facilities. Using Medicare's physician specialty codes, all such studies were categorized according to the specialties of the physicians who performed them. Ownership was determined by including only those claims for global or technical-component-only reimbursement. Physicians owning or leasing MRI facilities would use one or the other of these two types of claims. Professional-component-only claims were not included. Procedure volumes and growth trends were compared among radiologists and other specialists.
Results: From 2000 to 2005, private-office MRI examinations performed by radiologists increased by 83%. During the same period, private-office MRI examinations performed by nonradiologist physicians, either through owning or leasing the equipment, increased by 254%. Excluding studies performed by independent diagnostic testing facilities (for which physician ownership cannot be determined), nonradiologists' share of the private-office MRI market rose from 11% in 2000 to 20% in 2005. The nonradiologic specialties most actively involved in performing MRI were orthopedic surgery (161,296 Medicare studies in 2005), neurology (63,363 studies), primary care (58,092 studies), internal medicine subspecialties (34,317 studies), and neurosurgery (20,712 studies).
Conclusions: In the private-office setting in 2005, radiologists performed most MRI examinations. However, the growth rate from 2000 to 2005 among nonradiologist physicians was far higher, 254% compared with 83% among radiologists. Because scans performed by nonradiologists through ownership or leasing are subject to self-referral, the much more rapid growth among those physicians should be of concern to policymakers and payers.