Comparison of sonography and magnetic resonance imaging for the diagnosis of partial tears of finger extensor tendons in rheumatoid arthritis.

OBJECTIVE Finger extensor tenosynovitis in rheumatoid arthritis (RA) may lead to partial and eventually to complete tendon tears. The aim of this study was to investigate the diagnostic value of sonography (SG) and/or magnetic resonance imaging (MRI) to visualize partial tendon tears. METHODS Twenty-one RA patients with finger extensor tenosynovitis for more than 12 months underwent SG, MRI and surgical inspection, the latter being the gold standard. RESULTS For partial tears, sensitivity and specificity were 0.27 and 0.83 for MRI, and 0.33 and 0.89 for SG, respectively. Positive and negative predictive values were 0.35 and 0.78 for MRI, and 0.50 and 0.80 for SG, respectively. Accuracy was 0.69 for MRI and 0.75 for SG. CONCLUSION For visualization of partial finger extensor tendon tears in RA patients, SG performs slightly better than MRI, but both techniques are at present not sensitive enough to be used in daily practice.