Critically evaluating the role of diagnostic imaging in osteomyelitis.

Early diagnosis, essential for timely appropriate treatment and reduction of complications, can be difficult. This article aims to give an overview of the role that different imaging modalities have to play in the diagnosis of osteomyelitis. Osteomyelitis is a heterogeneous disease in its pathophysiology, clinical presentation, and management. It infers inflammation of bone and marrow, whereas osteitis is inflammation of the bone only. Thus, a soft-tissue infection that reaches the bone surface but has not infected the marrow is osteitis and not osteomyelitis. Chronic osteomyelitis is divided into active and inactive forms. Newly appearing periosteal reaction or bone destruction within the chronic involucrum are indicators of activation. Imaging modalities represent different underlying pathophysiological processes that may be represented in differing types and differing phases of osteomyelitis. Sequential selection of appropriate imaging modalities requires a thorough understanding of the disease processes and the process by which each modality visualizes this dynamic disease process.