Musculoskeletal ultrasonography assists the diagnostic performance of the 2010 classification criteria for rheumatoid arthritis

We investigated whether musculoskeletal ultrasonography (MSKUS) assists the diagnostic performance of the 2010 rheumatoid arthritis (RA) classification criteria. Sixty-nine early arthritis patients were consecutively enrolled. None of the patients had been treated. In MSKUS of bilateral wrist and finger joints from 22 sites, the findings obtained by gray-scale and power Doppler (PD) assessment were graded on a semiquantitative scale from 0 to 3. Plain magnetic resonance imaging (MRI) of both wrist and finger joints was also examined. Diagnosis of RA was defined by the initiation of disease-modifying antirheumatic drugs within the first 3 months. The diagnostic performance of the patients was evaluated at entry using 2010 RA classification criteria in conjunction with MSKUS. The indispensable MSKUS finding for differentiating RA was the presence of a PD grade 2 or 3 that was superior to 2010 RA classification criteria or MRI-proven bone edema. We propose that the decision tree algorithm of 2010 RA classification criteria with PD grade 2 or 3 reveals the best discriminative ability. MSKUS, especially with a strong PD signal, is very useful to assist the diagnostic performance of the 2010 RA classification criteria in the early recognition of RA.