Analyzing the Usage of Shear-Wave Elastography in Evaluating Ankylosing Spondylitis: A Literature Review

Ankylosing spondylitis (AS) is an autoimmune disease characterized by inflammation of the axial skeleton, sacroiliac (SI) joint, and entheses and typically presents with back pain/stiffness, disability, and decreased function. Early diagnosis is essential in improving the clinical outcomes of this disease. This review aims to evaluate the mechanical action of shear wave elastography (SWE) and its potential role in diagnosing and monitoring the treatment of AS. SWE is a newer ultrasound technique that utilizes low-frequency vibrations to assess tissue stiffness. Therefore, due to the progressive stiffness seen in AS, elastography can potentially evaluate and measure treatment response in AS by assessing tissue composition and elasticity. Strain elastography (SE), conversely, relies on externally applied compressive force to indirectly measure tissue stiffness by measuring the amount of tissue displaced. However, diagnostic value is limited by the ability of the operator to apply consistent force and provide absolute elasticity measurements. SWE and SE have been used to detect early musculoskeletal changes commonly seen in AS and offer advantages over conventional imaging modalities that may not be as sensitive. SWE has shown effectiveness through its quantitative measurement of tissue stiffness, which offers potential for better monitoring of disease progression and treatment effectiveness.