Radiologic Mimics of Osteomyelitis and Septic Arthritis: A Pictorial Essay

Figure 14

Sacroiliitis. Coronal STIR sequence of sacroiliac joints (SIJ) of a 34-year-old male with right acute on chronic and left chronic sacroiliitis. The region of the acute inflammatory process is denoted by the marrow oedema signal in the cartilaginous component of the right SIJ (arrow). Marrow fat infiltration (dotted arrow) adjacent to the left SIJ inferiorly implies prior inflammation. Irregular joint surface (dash) is consistent with erosion.