ABSTRACT
Ankylosing spondylitis (AS) is the disease entity on which the concept of the spondyloarthropathies (SpA) is based. The clinical, immunological, and imaging features of AS attest to the fact that its pathogenesis is fundamentally different from rheumatoid arthritis (RA) and that this disease is not indeed a form of RA or a “rheumatoid spondylitis” as once considered. After a brief description of the anatomical basis for AS, this chapter highlights the imaging of AS using radiography, ultrasonography, and concentrates mainly on magnetic resonance imaging (MRI), with a brief mention on computed tomography (CT) and bone scintigraphy.
