Inflammation of spinal structures is a characteristic feature of the spondyloarthritides (SpA). The term SpA covers patients with inflammatory back pain and/or peripheral arthritis who can be further categorized. Ankylosing spondylitis (AS), the prototype of the SpA, the most frequent inflammatory spinal disease in adults, usually starts in the sacroiliac joints. Pathologic spinal changes occurring in AS are spondylitis, spondylodiscitis and inflammation and ankylosis also at other sites in the axial skeleton. In the later stages of AS such changes can be well recognized by spinal x-rays. In the early disease stages it has been more difficult to analyze the exact anatomic localization of spinal inflammation to date, because conventional imaging systems have only a limited capacity to demonstrate such changes early. There is some evidence that magnetic resonance imaging (MRI) with fat saturation and contrast enhanced MRI are useful to visualize early and late inflammatory changes in the sacroiliac joints. In this paper we report that MRI is also useful to localize the site of inflammation to distinct regions of the spine in AS and other SpA.