Early-stage rheumatoid arthritis: Diagnostic accuracy of MR imaging

PURPOSE: To investigate the role of magnetic resonance (MR) imaging in diagnosing early rheumatoid arthritis (RA). MATERIALS AND METHODS: Twenty patients (three men, 17 women; age range, 21-72 years) with clinically and radiologically proved RA underwent evaluation to define an MR imaging criterion for diagnosing synovial inflammation due to RA. Twenty-seven patients (16 with RA, II without RA [control patients]; three men, 24 women; age range, 19-75 years) suspected to have early RA but without radiographic abnormalities underwent evaluation to test the accuracy of using the criterion to diagnose RA. In each patient, coronal, fat-suppressed, and gadolinium contrast material-enhanced, T1-weighted images of both hands were obtained. RESULTS: The MR imaging criterion was periarticular contrast material enhancement of the wrists or the metacarpophalangeal and/or proximal interphalangeal joints in both hands. In the diagnosis of early RA, sensitivity and negative predictive value were both 100%, specificity was 73%, and accuracy was 89%. CONCLUSION: MR imaging is extremely useful in diagnosing early RA.