Early rheumatoid arthritis-do we really know what it means? Consistency and distribution of MRI findings according to different definitions for early rheumatoid arthritis.

This study aims to characterize patients with early rheumatoid arthritis (RA) based on different definitions of early RA (disease duration, fulfillment of the American College of Rheumatology (ACR) criteria), and to determine whether these different definitions affect magnetic resonance imaging (MRI) findings of the hand. A cohort of 58 patients with early RA previously described was re-evaluated. There were 43 women and 15 men with a median age of 49 years, a disease duration of less than 2 years, and negative radiographs who were followed up for 6-41 months. MR images of the hand and wrist of these patients were retrospectively evaluated for the presence of synovitis, erosions, and tenosynovitis. The presence and distribution of these MRI findings were analyzed in three groups: fulfillment of 1987-ACR criteria, 6-month disease duration, and 12-month disease duration. Median disease duration was 11 months (range 1-24 months). Thirty patients (52%) fulfilled the ACR criteria. More patients fulfilling ACR criteria had MCP erosions and carpal synovitis compared with those not fulfilling the criteria; however, the difference was not significant. No significant difference was seen in the prevalence of synovitis, tenosynovitis, or erosions between the three groups. Patients with early RA of 2-years duration and negative hand X-ray findings are a homogenous group, regarding their MRI findings.