In this lesson, you’ll get a structured, spine-focused walkthrough of axial spondyloarthritis imaging — linking anatomy and biomechanics to the key inflammatory and structural lesions on MRI and how they evolve over time (active inflammation → fatty change → new bone formation/ankylosis). You’ll learn how to recognize and report vertebral corner/endplate changes (including erosions and “shiny corner”/sclerosis concepts), syndesmophyte formation up to classic bamboo spine appearances, and discovertebral involvement (Andersson-type lesions) with attention to the most important mimics such as discitis/osteomyelitis (including tuberculosis-like patterns). The lesson also highlights why posterior element disease (facet and costovertebral joints) matters, and gives practical guidance on sequence choices (STIR vs fat-suppressed T2/Dixon) to reduce common diagnostic pitfalls and improve day-to-day reporting consistency.

Learning objectives

By the end of this lesson, you should be able to:

• Identify and correctly describe the major inflammatory and structural spine lesions of axial spondyloarthritis on MRI (vertebral corner/endplate changes, erosions, fatty change, syndesmophytes, and ankylosis patterns).
• Differentiate key mimics and pitfalls, especially discovertebral lesions that can resemble infection (discitis/osteomyelitis, including tuberculosis-like patterns) and mechanical/degenerative changes.
• Select and optimize an MRI approach for suspected/known axial spondyloarthritis of the spine, including smart sequence choices (STIR vs fat-suppressed T2 / Dixon) and when to look beyond the vertebral bodies (facet/costovertebral joints, posterior elements, complications such as fractures).