F-FDG-PET/CT in Initiation and Progression of Inflammation and Infection.

OBJECTIVE

Detection/localization of infection and inflammation is important for the initiation of correct treatment as well as its maintenance. Nuclear medicine imaging methods play an important role in determining infection and inflammation. F-2'-deoxy-2-fluoro-d-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT) is highly sensitive in such cases when used with tomographic cross-sections. In this study, the development and progression of infection and inflammation were monitored on rats by using F-FDG via PET/CT.

METHODS

Sterile and infected abscesses were formed on rats using turpentine and S. aureus, respectively. For evaluation of the formation and progression of the abscess, F-FDG was injected into the rats and they were imaged by PET/CT at intervals of twenty-four hours for five days. Maximum standard uptake value (SUV) of F-FDG was calculated.

RESULTS

The highest activity involvement was seen on the first day of abscess formation. On the first day, SUV of the S. aureus abscess was 3.9±0.9 while in the sterile abscess SUV in the first day was 2.2±0.8. F-FDG uptake decreased day by day and it reached the background level on the fourth and fifth days. There were statistically significant differences between S. aureus and sterile abscess, and between sterile abscess and background activity in terms of SUV values during the first three days (p<0.05). On the fourth and fifth days, there was no statistically significant difference between S. aureus and sterile abscess, and between sterile abscess and background activity (p>0.05).

CONCLUSION

The results demonstrated that the SUV value for F-FDG can be useful in the early differentiation of sterile and infected abscess. In addition, F-FDG-PET imaging has the advantage of local availability of equipment and labeled agents leading rapid diagnosis of differentiation of infection and inflammation.