Solau-Gervais E et al. (2006) Magnetic resonance imaging of the hand for the diagnosis of rheumatoid arthritis in the absence of anti-cyclic citrullinated peptide antibodies: a prospective study. J Rheumatol 33: 1760–1765

Early diagnosis and treatment of rheumatoid arthritis (RA) is important if patients are to have the best possible prognosis. There is, therefore, a need for improved detection of early RA in patients with undifferentiated polyarthritis who do not show radiographically visible erosive changes, and who do not have antibodies to cyclic citrullinated peptides (anti-CCP antibodies; these are associated with severe RA).

In this prospective study, 30 patients with inflammatory polyarthralgia or synovitis of at least one joint underwent radiography of their hands, wrists, and feet, and MRI of their hands. Axial MRI views of carpal and metacarpal joints were scored according to the Outcome Measures in Rheumatology system. All patients in the study were negative for antibodies to CCP and had normal baseline radiographs. At 1-year follow-up, 16 patients were diagnosed with RA.

Baseline MRI scores for carpal erosion, synovitis, and tenosynovitis did not differ between patients diagnosed with and without RA. There was, however, a statistically significant difference between these two groups in MRI scores for metacarpophalangeal joint erosion (19.3 versus 7.7, respectively; P = 0.024), particularly in scores of the second and third metacarpophalangeal joints. Analysis showed that an MRI score >15 for metacarpophalangeal joint erosion had a specificity of 70% and a sensitivity of 64% for the prediction of RA.

Solau-Gervais and colleagues suggest that MRI scores for metacarpophalangeal joint erosion could be a useful tool in the early diagnosis of RA, especially in patients negative for antibodies to CCP.