EULAR-OMERACT ultrasound scoring system for synovitis in rheumatoid arthritis (RA)

The EULAR-OMERACT ultrasound scoring system for synovitis in rheumatoid arthritis (RA) is a standardized method for assessing synovial inflammation using ultrasound imaging. This scoring system was developed collaboratively by the European League Against Rheumatism (EULAR) and the Outcome Measures in Rheumatology (OMERACT) group to provide a consistent approach for evaluating synovitis in clinical trials and routine practice ¹.

Usage

The EULAR-OMERACT ultrasound scoring system for synovitis in RA provides a valuable tool for assessing disease activity and monitoring treatment response in clinical practice and research settings.

Classification

The scoring system includes predefined definitions and scoring criteria for assessing synovial inflammation in different joints commonly affected by RA, such as the wrist, proximal interphalangeal joints, knee and metatarsophalangeal joints. It typically evaluates synovial hypertrophy (thickening) and synovial vascularity (blood flow) as markers of inflammation.

B-mode ultrasound

• synovial hypertrophy assessment: B-mode ultrasound provides grayscale images that allow for the assessment of synovial hypertrophy, which refers to thickening of the synovial lining. The examiner evaluates the thickness of the synovial membrane relative to adjacent structures, such as tendon sheaths or joint recesses. This assessment is typically performed using a semiquantitative scoring system, where the severity of synovial hypertrophy is graded on a scale from 0 to 3.

Power doppler ultrasound

• synovial vascularity assessment: Power Doppler ultrasound is employed to assess synovial vascularity, which reflects the degree of inflammation within the synovium. This imaging modality detects the movement of red blood cells within blood vessels, providing a color-coded representation of blood flow. Increased vascularity within the synovium is indicative of active inflammation.

• semiquantitative scoring: Power Doppler signals are typically graded using a semiquantitative scoring system, where the intensity and distribution of Doppler signals within the synovium are assessed. The severity of synovial vascularity is graded on a scale from 0 to 3, with higher scores indicating increased vascularity and more significant inflammation.

Combined assessment

In the EULAR-OMERACT ultrasound scoring system, the assessment of synovitis often involves a combined evaluation of both synovial hypertrophy on B-mode imaging and synovial vascularity on power Doppler imaging. These assessments are integrated to provide a comprehensive evaluation of synovial inflammation in RA².