ROLE OF ULTRASOUND IN THE EVALUATION OF RHEUMATOID ARTHRITIS

Background: Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disorder primarily affecting synovial joints, leading to progressive joint damage, deformity, and disability if not adequately managed. Early and accurate evaluation of joint inflammation is critical for diagnosis, disease monitoring, and treatment optimization.
Conventional radiography, while commonly used, lacks sensitivity in detecting early soft tissue changes and synovitis.
Ultrasound (US), particularly with power Doppler capability, has emerged as a valuable, non-invasive, and dynamic imaging tool for real-time assessment of synovitis, tenosynovitis, joint effusion, bone erosions, and vascular activity in RA. Its portability, safety profile, and high sensitivity for inflammatory changes make it indispensable in the current rheumatologic imaging paradigm.
Aim: To evaluate the role of high-resolution musculoskeletal ultrasound in the detection, characterization, and monitoring of joint involvement in patients with rheumatoid arthritis, with particular emphasis on its sensitivity in detecting synovitis, erosions, and vascular activity compared to clinical examination.
Materials and Methods: This observational study included 60 adult patients with clinically diagnosed RA based on the 2010 ACR/EULAR classification criteria. All subjects underwent detailed clinical joint assessments followed by standardized musculoskeletal ultrasound using high-frequency linear probes (10–18 MHz). The most commonly affected joints—wrists, metacarpophalangeal (MCP), proximal interphalangeal (PIP), and knees—were evaluated for synovial hypertrophy, effusion, power Doppler signal, and bone erosions. Synovitis was graded semi-quantitatively
(Grades 0–3) per OMERACT guidelines. The ultrasound findings were compared with clinical swelling and tenderness scores to assess concordance. Data were statistically analyzed for sensitivity, specificity, and correlation.
Results: Ultrasound detected synovitis in 85% of joints clinically assessed as normal, demonstrating its superiority in identifying subclinical disease. Power Doppler signals were seen in 72% of joints with active inflammation, indicating ongoing synovial hyperemia. Bone erosions were visualized in 38% of cases, including early cortical breaks undetected on radiographs. There was significant discordance between clinical and sonographic findings, particularly in small joints. The sensitivity of ultrasound for detecting active synovitis was 91%, while clinical assessment showed 68%. Doppler-positive joints strongly correlated with higher disease activity scores (DAS28), supporting the utility of ultrasound in disease monitoring and treatment planning
Conclusion: Musculoskeletal ultrasound plays a critical role in the comprehensive evaluation of rheumatoid arthritis. Its ability to detect subclinical synovitis, monitor disease activity through power Doppler imaging, and visualize early erosions makes it a superior adjunct to clinical assessment. Integration of ultrasound into routine rheumatologic practice enhances diagnostic accuracy, allows early therapeutic interventions, and facilitates more precise disease monitoring.