CT can be helpful in identifying fluid collections adjacent to bone or surgical hardware that can be targeted for further investigation with percutaneous or surgical drainage. CT may also be useful in the detection of necrotic osseous fragments or sequestra that supply a nidus for chronic infection [21]. IV contrast should be considered because this may allow for better definition of fluid collections or fistulous communication to orthopedic implants [22]. FDG-PET/CT Area of Interest A systematic review by Govaert et al [21] found that FDG-PET/CT has specificity for posttraumatic osteomyelitis ranging from 76% to 100% and sensitivity ranging from 83% to 100%. However, in the acute setting, inflammation due to fracture or recent surgery may decrease accuracy. A retrospective review by Hartmann et al [30] demonstrated sensitivity of 100% and specificity ranging from 88% to 93%. This study included patients with orthopedic implants and joint replacements. This small study of 33 patients also suggested that FDG-PET was most specific when evaluating infection in the axial skeleton. Wenter et al [22] retrospectively reviewed PET imaging performed in 215 patients for suspected osteomyelitis or implant associated infection and reported sensitivity of 88% and specificity of 76%. Their results also showed no significant decrease in accuracy in patients with orthopedic implants. MRI Area of Interest MRI is useful for the evaluation of osteomyelitis or soft tissue infection in the setting of extra-articular surgical hardware. MRI allows for characterization of both bone marrow signal and adjacent soft tissues. Recent advances in metal artifact reduction techniques have improved orthopedic hardware imaging, particularly in the appendicular skeleton [31]. In the setting of posttraumatic osteomyelitis, MRI can be used to determine the degree of osseous and soft tissue involvement.
Suspected Osteomyelitis Septic Arthritis or Soft Tissue Infection Excluding Spine and Diabetic Foot PCAs. CT can be helpful in identifying fluid collections adjacent to bone or surgical hardware that can be targeted for further investigation with percutaneous or surgical drainage. CT may also be useful in the detection of necrotic osseous fragments or sequestra that supply a nidus for chronic infection [21]. IV contrast should be considered because this may allow for better definition of fluid collections or fistulous communication to orthopedic implants [22]. FDG-PET/CT Area of Interest A systematic review by Govaert et al [21] found that FDG-PET/CT has specificity for posttraumatic osteomyelitis ranging from 76% to 100% and sensitivity ranging from 83% to 100%. However, in the acute setting, inflammation due to fracture or recent surgery may decrease accuracy. A retrospective review by Hartmann et al [30] demonstrated sensitivity of 100% and specificity ranging from 88% to 93%. This study included patients with orthopedic implants and joint replacements. This small study of 33 patients also suggested that FDG-PET was most specific when evaluating infection in the axial skeleton. Wenter et al [22] retrospectively reviewed PET imaging performed in 215 patients for suspected osteomyelitis or implant associated infection and reported sensitivity of 88% and specificity of 76%. Their results also showed no significant decrease in accuracy in patients with orthopedic implants. MRI Area of Interest MRI is useful for the evaluation of osteomyelitis or soft tissue infection in the setting of extra-articular surgical hardware. MRI allows for characterization of both bone marrow signal and adjacent soft tissues. Recent advances in metal artifact reduction techniques have improved orthopedic hardware imaging, particularly in the appendicular skeleton [31]. In the setting of posttraumatic osteomyelitis, MRI can be used to determine the degree of osseous and soft tissue involvement.