Magnetic resonance imaging (MRI) is a highly reliable tool for diagnosing ankylosing spondylitis. MRI can identify cartilage abnormalities, subcortical erosions, bone marrow edema with inflammation, and synovial enhancement. Subchondral sclerosis and juxta-articular fat deposition are noted in the chronic stage of ankylosing spondylitis. Spinal changes associated with spondyloarthropathy are florid anterior spondylitis (or Romanus lesion), florid diskitis (Anderson lesion), ankylosis, and arthritis of the apophyseal and costovertebral joints. A MRI grading system for inflammation in sacroiliac joints and the spine could help clinicians evaluate the anti-inflammatory efficacy of therapeutics. Newer technologies based on MRI are aimed at broadening the diagnostic scope and facilitating the quantification of active inflammation but still require extensive validation.

Keywords: Ankylosing spondylitis, Spondyloarthropathies, Sacroiliitis, Magnetic resonance imaging