Imaging of osteomyelitis and musculoskeletal soft tissue infections

The diagnostic imaging of osteomyelitis can require the confluence of multiple imaging technologies. Conventional radiography should always be the first imaging modality. Sonography is most useful in the diagnosis of fluid collections in a joint or in the extra-articular soft tissues but is not useful for evaluating presence of osseous infection. CT scan can be a useful method to detect early osseous erosion and to document the presence of sequestrum, foreign body, or gas formation but generally is less sensitive than other modalities for the detection of bone infection. Nuclear medicine and MRI are the most sensitive and most specific imaging modalities for the detection of osteomyelitis. Nuclear medicine is particularly useful in identifying multifocal involvement, which is common in children. MRI provides more accurate information of the local extent of the soft tissues and possible soft tissue abscess in patients with musculoskeletal infection.