Abstract
1334
Objectives: Osteomyelitis is a common complication in diabetic foot, while the level of serum glucose is often difficult to control in such setting. It is well-known that hyperglycemia/hyperinsulinemia can reduce the accuracy of FDG-PET in the evaluation of a variety of malignancies. In addition, in patients with diabetes, lowing glucose level by administration of insulin usually drives FDG into the muscle and adipose tissue, therefore, decreasing the contrast between the lesion and the background. The effect of hyperglycemia/hypernsulinemia on the accuracy of FDG-PET in the evaluation of infection is not well-defined. Previous publications have indicated that moderate hyperglycemia may not have significant effect on accumulation of FDG in the site of infection and inflammation. The aim of this investigation is to determine if the serum glucose levels adversely affect the diagnostic accuracy of FDG-PET in THE evaluation of diabetic foot.
Methods: Twenty-one consecutive diabetic patients with hyperglycemia and with suspicion of infection in the foot were included in this investigation. Patient fasted from midnight to time of imaging in the morning. Their serum glucose levels prior to FDG injection were all above 150mg/dl (range 157 to 259mg/dl, 187.4±24.5mg/dl). The PET images of feet were blindly read by two experienced nuclear medicine physicians and their interpretations of images were compared to the final outcome, which was based on surgical pathology or long-term clinical follow-up. The serum glucose levels were compared between accurate with inaccurate groups, and between infected with non-infected groups.
Results: Nine patients were proven to have deep skeletal infection/osteomyelitis. FDG-PET accurately identified 8 of these patients with a sensitivity of 88.9% (8/9). In 12 patients without osteomyelitis, FDG-PET successfully excluded all 12 patients with a specificity of 100% (12/12). The overall accuracy in diagnosis of osteomyelitis with FDG-PET was 95.2% (20/21). One patient had false negative diagnosis.
Conclusions: FDG-PET offers a rapid, sensitive high-resolution tomography in the evaluation of diabetic foot despite relatively high serum glucose and unpredictable serum insulin levels. The mildly to moderately elevated serum glucose levels do not appear to affect the accuracy of the FDG-PET in diagnosis of osteomyelitis in patients with diabetic foot.
- Society of Nuclear Medicine, Inc.