A comparison of ultrasonography and magnetic resonance imaging in the evaluation of temporomandibular joint involvement in rheumatoid arthritis and psoriatic arthritis

Objective. To define the diagnostic value of ultrasonographic (US) examination in comparison with magnetic resonance imaging (MRI) for the assessment of temporomandibular joint (TMJ) involvement in rheumatoid arthritis (RA) and psoriatic arthritis (PsA). Methods. MRI and US examinations were performed in 33 patients (22 with RA and 11 with PsA). Alterations of the disc, alterations of the condyle and joint effusion were evaluated. Results. Pathological changes of the TMJ were observed by MRI in 24 patients and by US in 31 patients. The sensitivity and specificity of US were calculated in comparison with MRI. The sensitivity was 72.2% and the specificity was 60% in the assessment of pathological changes of the TMJ. The sensitivity was 69.6% with specificity of 30.0% in the assessment of alterations of the disc; the sensitivity was 70.6% with specificity of 75.0% in the assessment of joint effusion. Significant concordance was not observed in the assessment of condylar alterations. Conclusions. US imaging appears able to detect different pathological changes of the TMJ and may be considered an important diagnostic tool for clinical evaluation of the TMJ in RA and PsA.