Background: We evaluated the extent and the degree of active atherosclerosis in the popliteal-tibial arteries by quantitative techniques using [(18)F]-2-fluoro-2-deoxy-d-glucose-positron emission tomography (FDG-PET). An effort was made to determine whether there was a positive correlation between the level of ongoing atherosclerosis and subsequent chronic ischemia in the diabetic foot.
Methods: A total of 115 diabetic patients were enrolled in this prospective research study and underwent lower-extremity FDG-PET and magnetic resonance imaging. We selected 36 diabetic patients with complicated diabetic foot for this analysis (11 men, 25 women; mean age, 59.5 years; age range, 36-85 years). Ten nondiabetic control participants (6 men, 4 women; mean age, 59.7 years; age range, 27-88 years) were also included for comparison. Only patients with blood glucose levels less than 200 mg/100 mL were enrolled in this study. The metabolic volumetric product (MVP), for each patient was calculated multiplying foot average maximum standard uptake value (SUV(max)) by foot volume. Pearson correlation analysis between foot mean SUV(max) alone and the degree of atherosclerosis and between the foot MVP and the degree of atherosclerosis was performed as measured by FDG-PET. A t test was used to assess for significant differences in foot SUV(max) and foot MVP among varying degrees of atherosclerosis, using P < .05 as the criterion for statistical significance.
Results: Foot SUV(max) significantly correlated (P < .05) with the ratio of popliteal-tibial artery SUV(max) to background SUV (Pearson correlation coefficient = 0.49). Foot MVP was also significantly correlated (P < .05) with the ratio of popliteal-tibial artery SUV(max) to background SUV (Pearson correlation coefficient = 0.69).
Conclusions: Using FDG-PET, one may be able to detect and quantify the degree of increased metabolic activity of early active atherosclerosis and the associated chronic tissue ischemic effects at the regional level and globally throughout the whole body during the asymptomatic phase of disease.