Osteomyelitis is an infection of the bone and bone marrow. It may be easily missed on chest radiographs if one does not pay careful attention to the bones in addition to the lung fields. Typical findings of acute osteomyelitis on plain radiographs are soft tissue swelling, periosteal reaction, cortical irregularity, and demineralization. In chronic osteomyelitis, there is thick, irregular, sclerotic bone with radiolucencies and an elevated periosteum. The image shown is from a patient with chronic osteomyelitis of the left clavicle with bony expansion, sclerosis, and periosteal reaction (arrow). Note the size difference compared to the right clavicle.
