Fig. 1

Typical FDG PET maximum intensity projection (MIP) images of patients with axial or peripheral spondyloarthritis. a Images of an 80-year-old man with axial spondyloarthritis (ankylosing spondylitis) showing increased uptake at the sternoclavicular and sternocostal, spinal, and sacroiliac joints. b Images of a 55-year-old man with peripheral spondyloarthritis (undifferentiated spondyloarthritis) showing increased uptake at each peripheral articular, including shoulders, elbows, wrists, hands, hips, knees, and feet and in the spine