Osteomyelitis and pyogenic infection of the sacroiliac joint. MRI findings and review.

Acute pyogenic sacroiliac joint infection and osteomyelitis of adjacent bones often present with severe, poorly localized lower back, pelvic or hip pain. Five cases of sacroiliac joint infection or sacroiliac bone osteomyelitis were evaluated by MRI. MRI may be a helpful diagnostic tool to evaluate early changes of infection in the sacroiliac area. It is very sensitive for detecting bone marrow abnormalities; however, it is non-specific and can not accurately differentiate osteomyelitis from sacroiliitis.