Background The treatment of rheumatoid arthritis (RA) aims clinical remission and arrest of radiological damage. Clinical evaluation alone results inadequate in assessing disease activity, and imaging studies have become integrative assessment tools (1). Power Doppler (PD) allows easy and immediate validation of persistent disease activity, but Contrast-enhanced ultrasound (CEUS) shows higher sensitivity than PD in detecting residual synovial inflammation (2,3). Despite CEUS is easy, fast to perform and contrast agent is innocuous, optimal application is limited to one joint and right joint to evaluate may be missed.
Objectives To demonstrate validity of CEUS to detect synovial activity compared to PD on patient-based indication controlled by contrast-enhanced MRI (CE-MRI).
Methods 32 patients diagnosed with RA where asked to indicate most active felt hand joint. On this joint first PD study was performed by experienced rheumatologist with 12-18 MHz linear probe on Esaote MyLab70 using grading score 0-3 and second CEUS study was performed after injection of contrast bolus (Sonovue®) on Esaote MyLab 25 with CnTI evaluated by 3 different radiologists using grading score 0-2. As control all patients performed CE-MRI and synovitis was graded 0-3 for all joints by experienced radiologist. Results of CEUS and PD on most active joint indicated by patient were referred to CE-MRI.
Results In all 32 cases most active joint felt by patient was joint with highest synovitis grade on CE-MRI (100%). It was the wrist in 53,2% of cases, a metacarpophalangeal in 31,2% and proximal interphalangeal joint in 15,6%. CEUS revealed active synovitis in this side in all cases; sensitivity resulted 100%. Interoperator agreement in assessing CEUS grade was highly significant (kappa=0,83). PD showed inferior sensitivity with false negative assessment in 28,2% of patients. PD and CEUS grade did not correlate significantly with synovitis grade of CE-MRI, although median values were different between CEUS grade 1 and grade 2. Low number of patients may inhibit statistical significance.
Conclusions CEUS confirms higher sensitivity compared to PD in detecting synovitis. Patients’ discomfort only is effective to identify joint for CEUS assessment.
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Disclosure of Interest None Declared