Intensity of ¹⁸F-FDG PET Uptake in Culture-Negative and Culture-Positive Cases of Chronic Osteomyelitis

Figure 2

A 25-year-old man with an indolent Brodie’s abscess in the proximal tibia (case #8). The patient had been hospitalized for knee pain 10 years earlier, but no specific diagnosis was made. He now suffered a sports related ACL ligament rupture of his left knee. As an incidental finding, anterior-posterior and lateral radiographs (a) showed cystic lesion with surrounding sclerosis in the proximal tibia. Coronal and transaxial MR-images (b) demonstrated a 2 cm sclerotic osseous lesion with contrast medium enhancement and oedema of the surrounding tissues. Coronal and transaxial ¹⁸F-FDG PET images (c) showed an increased local uptake of the tracer. Compared with the corresponding ROI of the contralateral tibia, ratio was 10.1 and ratio 20.51. The lesion was correctly characterized with infection scintigraphy with labeled antibody fragments (LeukoScan) (d) and three-phase bone scintigraphy (e). Based on percutaneous biopsy samples taken under fluoroscopy, the final histological diagnosis was Brodie’s abscess and the microbiologic culture revealed S. aureus as the causative pathogen.

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