Paucity of bone scan abnormalities in a child with multifocal osteomyelitis and disseminated sepsis

Full text: We present an unusual case of multifocal osteomyelitis with minimal bone scan abnormalities and markedly discordant findings on Magnetic Resonance Imaging(MRI) and gallium scans. A seven-year-old female presented with left leg, right elbow pain and fever. A bone scan was performed. Mild increased vascularity was demonstrated on the dynamic and blood pool phases of the study in the area of the right elbow. In the delayed images there was a photopenic lesion in the left distal femoral metadiaphysis and also irregular uptake in the metaphyseal regions of the long bones. Low grade soft tissue tracer uptake was seen in the left thigh and right forearm. The patient deteriorated clinically and underwent further investigations with MRI and gallium scans. The MRI showed extensive abnormalities with mulitlocular fluid collection seen throughout most of the muscle groups of both thighs suggesting myositis with an associated cellulitis and osteomyelitis of the left femur. The gallium study was markedly abnormal with increased uptake in the distal 2/3rds of the left femur, proximal 1/2 of the right femur, right proximal forearm (mid forearm extending to mid upper arm), left proximal humerus and right hemithorax especially the lower zones. Staphylococcal aureus was cultured. The patient required intensive care management and slowly responded to antibiotic therapy and surgery to drain abscesses in the thighs. A bone marrow biopsy was normal and immunological tests were performed but a result has yet to be determined. The lack of increased bone uptake in the demonstrated areas of osteomyelitis maybe explained on the basis of an overwhelming infective process inhibiting the patient's healing response. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc