Quantitative magnetic resonance imaging of the hands and wrists of children with juvenile rheumatoid arthritis.

OBJECTIVE: To assess feasibility of measuring synovial volume in the hand and wrist in patients with polyarticular course juvenile rheumatoid arthritis (JRA) by magnetic resonance imaging (MRI). As well, to compare clinical variables with synovial volume calculated from MRI in patients receiving disease modifying or biologic therapy.
METHODS: Ten patients with polyarticular course JRA starting methotrexate (n = 3) or etanercept (n = 7) therapy had MRI with intravenous contrast performed of one hand and wrist at baseline and after 6 weeks and 3 months of pharmacotherapy. Synovial volume was determined for the entire hand and wrist and also for regions. Patients were assessed clinically by the core set of outcome variables for JRA and total hand swelling score, and assessed for clinical improvement based upon change in these variables.
RESULTS: Increased synovial volume was observed at entry by MRI in all patients (range 2.4-12.5 cc, median 3.7 cc). Correlation of total synovial volume from MRI with total hand swelling score at each timepoint was good (r = 0.52-0.68). Correlation with other clinical variables was not consistently strong. Patients who improved clinically did not differ from patients who did not improve clinically with respect to change in synovial volume.
CONCLUSION: Determining synovial volume in the hand and wrist in patients with JRA by MRI is feasible and correlates with total hand swelling assessed on physical examination. Inconsistent or poor correlation with other clinical variables and the clinical definition of improvement requires further study.