Discordance between MRI and bone scan findings in a child with acute complicated osteomyelitis: scintigraphic features that contribute to the early diagnosis.

Early diagnosis and prompt treatment of acute osteomyelitis are of paramount importance in children because they can prevent irreversible bone damage. Magnetic resonance imaging (MRI) with its superior spatial resolution and lack of ionizing radiation is routinely preferred over bone scan for this purpose. Increased blood flow, hyperemia and focally increased tracer uptake shown by "three phase" bone scan are the typical scintigraphic findings of acute osteomyelitis. In addition, diffuse uptake along the shaft of long bones and focal "cold" lesions are two special features that may be highly suggestive of infective periostitis, soft tissue sepsis and subperiosteal abscess formation, due to the loose attachment of periosteum to bone during childhood. We present a case of complicated osteomyelitis in a child with inconclusive MRI correctly diagnosed on the basis of these special scintigraphic findings resulting in treatment change from double i.v. Vancomycin--Ceftriaxone scheme to surgical intervention.