Review pathophysiology of osteomyelitis(OM) and correlation with imaging findings throughout the body Describe different chronicities of OM and variation of presentation by age Discuss the roles of various forms of imaging to diagnose OM with emphasis on nuclear medicine’s evolving role

OM occurs due to hematologic spread(most common route), contiguous spread from a an adjacent soft tissue infection(Figure 1) or by direct inoculation during surgery or trauma. Inciting infection of the bacteria creates an inflammatory process with resultant resorption of bone. Staphylococcus aureus is the most common pathogen responsible for hematogenous OM. Microorganism inoculation of bone causes alterations in pH and increased capillary permeability; leading to regional edema, leukocyte recruitment, cytokine release, tissue breakdown, decreased oxygen tension, increased local pressure, small vessel-thrombosis and bone deterioration(1). The...

Pathologic correlates with signs of osteomyelitis Acute OM Soft tissue swelling: result of a leaky vasculature from infectious process, causing edema and due to penetration of the periosteum from the infection(1). Osteopenia and lucent lesions: spread of infection within the medullary space, Haversian and Volkmann canals; resulting in abscess and destruction of the trabeculae(1). Cortical fissuring: due to spread of infection through haversian system with osteoclastic bone resorption(5)(Figure 7). Subperiosteal abscess: due to spread of infection into the cambium from the medullary cavity but can...

Understanding this complex disease process and identifying specific findings, which can aid in differentiating OM from other bone lesions is invaluable to the practicing radiologist. A subperiosteal abscess is often mistaken for a bone tumor in the pediatric population, the presence of intracellular bone marrow fat within the lesion helps to distinguish this entity as an infectious process. Knowledge of expanding imaging modalities allow for better consultation with ordering physicians. While plain radiographs remain the first line study, even subtle findings can take weeks to...

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