The earliest radiographic changes of osteomyelitis in the long bones is deep-seated edema manifesting as soft tissue swelling and obliteration of the intermuscular planes adjacent to the affected bone. Similarly, the early change of rib osteomyelitis is pericostal edema demonstrated by soft tissue swelling of the thoracic wall accompanied by an adjacent inward pleural displacement. In both osteomyelitis of the rib and the long bones, the bony changes will appear 1-2 weeks later. Pericostal edema can be readily diagnosed by ultrasound scan. Pericostal edema, although non specific and can occur in other conditions, yet it is a strong warning sign, set within the overall clinical picture of osteomyelitis.