Purpose: Pedal osteomyelitis is a worrisome complication of diabetic foot disease. Controlling serum glucose levels is difficult for many diabetic patients. High serum glucose levels could potentially affect the results of fluorine-18 fluorodeoxyglucose (18F-FDG) PET imaging in the detection of osteomyelitis. The aim of this investigation was to determine whether high serum glucose levels diminish the diagnostic accuracy of 18F-FDG PET imaging in detecting pedal osteomyelitis in diabetic patients.
Materials and methods: Forty-eight consecutive diabetic patients with a suspicion of pedal osteomyelitis were included in this investigation. At the time of 18F-FDG administration, 21 patients had serum glucose levels less than 150 mg/dl (group A), and 27 had serum glucose levels greater than 150 mg/dl (group B). Results of PET imaging were compared with final diagnostic outcome based on histopathology and/or 12 months' clinical follow-up.
Results: Osteomyelitis was confirmed in 17 patients. 18F-FDG PET correctly detected osteomyelitis in 15 of 17 patients for a sensitivity of 88.3% (15/17). This technique successfully excluded osteomyelitis in 30 of 31 cases for a specificity of 96.8% (30/31) and an overall accuracy of 93.8% (45/48). The sensitivity of 18F-FDG PET imaging was 87.5% (7/8) in patients with serum glucose levels less than 150 mg/dl (group A) and 88.9% (8/9) in patients with serum glucose levels greater than 150 mg/dl (group B). These results do not significantly differ from the overall sensitivity of 88.3% (15/17).
Conclusion: Mildly to moderately elevated serum glucose levels do not adversely affect the accuracy of 18F-FDG PET imaging in the detection of pedal osteomyelitis in diabetic patients.