To systematically evaluate the literature addressing the role of magnetic resonance imaging (MRI) in the diagnosis and prognosis of early undifferentiated inflammatory arthritis and rheumatoid arthritis (RA).
We performed a systematic literature review of the performance characteristics of MRI for diagnosing and prognosticating RA. We searched Ovid, supplementing this with manual searches of bibliographies, journals, meeting proceedings, and the ClinicalTrials.gov web site. To identify diagnostic studies, we included studies of any duration that prospectively examined whether MRI findings predicted RA diagnosis and reported adequate information to calculate sensitivity and specificity. To identify prognostic studies, we included prospective studies with at least a 12-month followup period that measured both baseline MRI findings and clinical and/or radiographic outcomes.
For diagnostic studies (n = 11), sensitivity and specificity of MRI findings for RA diagnosis ranged from 20-100% and 0-100%, respectively, depending upon the criteria used. Diagnostic performance of MRI improved when lower-quality studies or studies with longer disease duration were excluded. For prognostic studies (n = 17), MRI findings did not predict clinical remission, and the ability to predict radiographic progression varied significantly (range 18-100% for sensitivity and 5.9-97% for specificity). Restricting the analysis to specific MRI findings or earlier disease improved MRI prognostic performance. The only prognostic study reporting 100% of a priori quality criteria found MRI bone edema to be the strongest predictor of radiographic progression.
Data evaluating MRI for the diagnosis and prognosis of early RA are currently inadequate to justify widespread use of this technology for these purposes, although MRI bone edema may be predictive of progression in certain RA populations.