Musculoskeletal imaging: medicare use, costs, and potential for cost substitution.

Purpose: The current study explores the substitution of ultrasound (US) for magnetic resonance imaging (MRI) of musculoskeletal (MSK) disorders by describing the recent use and costs of MSK imaging in the Medicare population, projecting these trends from 2006 to 2020, and estimating cost-savings involved in substituting MSK US for MSK MRI, when appropriate.
Methods: The study used government-published data sets and de-identified Radiology Information System records exempt from institutional review board approval. From 1 year's MSK MRI records (n = 3,621), the proportion of cases in which US could be substituted for MRI was estimated. The use rates for 4 modalities of MSK imaging and average costs were determined from government Medicare data sets from 1996 to 2005. Regression analysis was used to project use rates from 2006 to 2020. The effect on costs of substitution was calculated.
Results: For the Medicare population, although there has been a moderate overall increase (25.7%) in MSK imaging, MSK MRI has increased 353.5% from 1996 to 2005. Projected MSK imaging costs in 2020 are $3.6 billion, of which $2.0 billion will be for MRI. A study of 3,621 MSK MRI reports indicates that 45.4% of primary diagnoses and 30.6% of all diagnoses could have been made with MSK US. The substitution of MSK US for MSK MRI, when appropriate, would lead to savings of more than $6.9 billion in the period from 2006 to 2020.
Conclusion: MRI MSK use has grown substantially from 1996 to 2005. The substitution of MSK US, when appropriate, would lead to large cost-savings for Medicare.