Radionuclide Imaging of Septic Joints and Their Differentiation from Periarticular Osteomyelitis and Cellulitis in Pediatrics

Abstract

Thirty-eight children who had septic arthritis, juxtaarticular osteomyelitis, cellulitis or a combination thereof were studied on consecutive days with ^99mTc-methylene diphosphonate (^99mTc-MDP) and ⁶⁷Ga-citrate (⁶⁷Ga) imaging, respectively, in an attempt to make a definitive diagnosis. The ^99mTc-MDP uptake reflects the bone response to the septic process, whereas ⁶⁷Ga seems to be concentrated at the site of infection by the inflammatory components. By utilizing the information from both modalities the septic focus was disclosed in all cases, and in the majority of patients the precise location of the infection, i.e., bone, synovium, or adjacent soft tissue was possible. The relatively poor resolution of the gamma camera vis a vis radiography was the limiting factor, particularly with infants, in determining the exact site of the septic process. Early in the evolution of the disease radionuclide imaging is considerably more sensitive than radiography.