Tagged WBC scan, bone scan, and SPECT-CT in patient with periprosthetic osteomyelitis

Suspected periprosthetic infection in a 72-year-old male with history of bilateral total knee replacements. A combined white cell and marrow scan was performed.

(A) Indium 111-labelled white cell scan of the knees demonstrates accumulation of radiolabelled white cells in the left knee between the 3-hour and 24-hour images (arrows).

(B) The technetium 99m-labelled bone marrow scan provides a baseline map of physiological white cell uptake. No tracer uptake is seen in the left knee (thick arrows). The discordance between the white cell and marrow scan demonstrates that the white cell uptake is likely to be due to a focus of infection.