Imaging of osteomyelitis with FDG PET-MR

Osteomyelitis is an inflammatory process accompanied by bone destruction, and is caused by microorganism infection. The infection can be limited to a single portion of the bone or can involve several compartments such as marrow, cortex, periosteum and the surrounding soft tissue. Osteomyelitis can be (1) spread locally from a focal source of infection, (2) secondary to vascular insufficiency, or (3) caused by hematogenous spread of the microorganism from a different source.For osteomyelitis in the extremities, the most common pathogen is Staphylococcus aureus. In skull-base osteomyelitis (SBO) it is Pseudomonas aeruginosa (50–90% of cases) [1]. Osteomyelitis of the skull base most often occurs as a complication of otitis externa, and can be categorized within the first category of focal infections. However, it is perceived as a special case due to the severe complications that can arise, given the location. The bacterial infection causes bone erosions, and uses fascial planes and venoussinuses for distant tissue invasion. It then can progress and spread to the surrounding osseous and soft tissues via the skull base