Is power Doppler ultrasound useful to evaluate temporomandibular joint inflammatory activity in juvenile idiopathic arthritis?

Objective To evaluate the effectiveness of power Doppler ultrasound (US) in assessing the temporomandibular joint (TMJ) involvement in juvenile idiopathic arthritis (JIA) patients using contrast-enhanced magnetic resonance imaging (MRI) as the reference standard. Methods We evaluated the US and MRI examinations of the TMJs from 92 JIA patients. These exams were done and scored for inflammatory activity on the same date. Results There were considerable differences between the US and MRI findings, with MRI detecting more effectively the TMJ involvement. No association was found between synovial inflammation obtained using power Doppler US to assess synovial vascularity determined by US images and synovial enhancement determined by MRI images. US had very poor sensitivity and very low positive predictive value to detect TMJ arthritis in JIA patients compared with MRI as the reference standard. Conclusions Power Doppler US cannot replace MRI for the detection of TMJ inflammatory involvement in JIA patients.