Bilateral MR imaging of the hand and wrist in early and very early inflammatory arthritis: tenosynovitis is associated with progression to rheumatoid arthritis.

Purpose: To identify bilateral hand and wrist findings of synovial inflammation associated with progression to rheumatoid arthritis (RA) in very-early-RA cohort (VERA) (duration, <3 months) and early-RA cohort (ERA) (duration, <12 but >3 months), to test tenosynovitis as a magnetic resonance (MR) imaging additional parameter for improving diagnostic accuracy of the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) RA classification criteria, and to evaluate the symmetry of joint and tendon involvement.
Materials and Methods: With institutional review board approval and informed consent, 32 women and three men (mean age, 45 years) with untreated recent-onset inflammatory arthritis participated in this prospective study and underwent MR imaging of both wrists and hands. After 12-month follow-up, 25 patients fulfilled the criteria for RA (10 VERA and 15 ERA patients). Ten patients did not fulfill the criteria for RA (non-RA [control] group). Possible associations between synovitis for each joint and tendon and RA diagnosis at 12 months were tested (univariate logistic regression analysis). Diagnostic performance of the ACR/EULAR RA classification criteria was evaluated (receiver operating characteristic curve analysis). Asymmetry prevalence (all joints and tendons in the analysis) was calculated.
Results: Tenosynovitis of the extensor carpi ulnaris (odds ratio, 3.21) and flexor tendons of the second finger (odds ratio, 14.61) in VERA group and synovitis of the radioulnar joint (odds ratio, 8.79) and tenosynovitis of flexor tendons of the second finger (odds ratio, 9.60) in ERA group were significantly associated with progression to RA (P < .05). Consideration of tenosynovitis improved areas under the receiver operating characteristic curve of ACR/EULAR criteria performance for the diagnosis of RA from 0.942 (P < .0001; sensitivity, 52%; specificity, 100%) to 0.972 (P < .0001; sensitivity, 76%; specificity, 100%), with cutoff score of 6 or greater. Asymmetry was found in 80.0% (62 of 77) (VERA patients) and 69.3% (106 of 153) (ERA patients) of joint or tendon pairs (P < .05).
Conclusion: Tenosynovitis is an imaging finding in early RA, and its inclusion as a scoring criterion might contribute for a better diagnostic performance of the 2010 ACR/EULAR classification; early RA is an asymmetric disease.
(© RSNA, 2012)