Radiology, Vol 185, 53-61, Copyright © 1992 by Radiological Society of North America
Deployment and utilization of MR imaging in Michigan: observations of a statewide data base
A Doughty, SI Nash and DA Gift
Michigan Department of Public Health, Lansing.
Patterns of deployment and utilization of magnetic resonance (MR) imaging
were studied with a Michigan Department of Public Health data base
containing data regarding more than 218,000 patient visits. Michigan
currently has 16 hospital-based fixed MR systems (magnets), 14 (13
operational) freestanding fixed magnets, and 11 (10 operational) mobile
magnets operating at 45 host sites. The imaging volume for 1991 was
approximately 127,000 procedures, with associated charges of $126,500,000.
Central nervous system imaging accounted for 82.6% of procedure volume,
with extremities accounting for another 12.9%. The average total charge per
procedure ranged from $844 to $1,076, and the average professional charge
per procedure ranged from $178 to $226. The annual throughput ranged from
1,356 to 7,480 procedures per magnet. Wide variation in many measures was
observed both within and among hospital-based, freestanding, and mobile
facility types. The use of computed tomography (CT) before MR imaging for
the same diagnostic problem continues to be substantial (average, 44% for
MR imaging of the head). Patterns of inpatient imaging and prior use of CT
indicate that the technical benefit of mobile MR imaging should be
investigated further.
