Magnetic resonance differentiation of acute and chronic osteomyelitis in children.

A comparison has been made of the MRI findings of 17 studies in 16 patients with osteomyelitis: eight studies were performed in patients with acute osteomyelitis, six in chronic and three in healed osteomyelitis. Soft tissues, cortex and marrow were assessed in all patients. The best predictors of acute osteomyelitis were poorly defined soft tissue planes, absence of cortical thickening, and a poor interface between normal and diseased marrow. In contrast, chronic osteomyelitis was suggested by the presence of well-defined soft tissue abnormality, thickened cortex, and a relatively good interface between normal and diseased marrow. The appearance of osteomyelitis did not vary in different anatomic sites.