Axial spondyloarthritis (axSpA) is a chronic inflammatory condition that primarily affects the spine and sacroiliac joints. Unfortunately, its diagnosis is often delayed for years due to the nonspecific nature of its main symptom: back pain. AxSpA is categorized into two subtypes: nonradiographic axSpA (nr-axSpA), which does not show changes on X-rays, and radiographic axSpA (r-axSpA or ankylosing spondylitis), which does exhibit significant structural changes in the sacroiliac joints.

Imaging plays a crucial role in detecting early sacroiliitis associated with axSpA, enabling timely intervention. The 2009 ASAS classification highlighted bone marrow edema (BME) as a key MRI feature for diagnosing nr-axSpA. This advancement enhances diagnostic reliability by overcoming the limitations of traditional radiographic methods and underscores the importance of MRI in achieving greater diagnostic precision in the assessment of axial spondyloarthritis.