Hybrid imaging of vascular graft infection by positron emission tomography with computed tomography using fluorine-18-labeled fluorodeoxyglucose: The Serbian National PET Center experience

Abstract

Introduction. Positron emission tomography (PET) with computed tomography (CT) using fluorine- 18-labeled fluorodeoxyglucose (18F-FDG PET/CT) is a hybrid diagnostic method based on the cell?s glucose uptake detection, which correlates with the degree of disease activity. While other diagnostic procedures fail to evaluate functional tissue, 18F-FDG PET/CT can be helpful in discovering active disease in patients with vascular graft infection. Methods. This cohort retrospective study included 22 patients (17 male, five female; aged 61.7 ? 16.1) with suspected vascular graft infection. Blood analyses and CT were performed in all patients. Degree of glucose uptake was evaluated visually and semiquantitatively using maximal standardized uptake value (SUVmax). Findings were considered positive if focal fluoro-deoxyglucose (FDG) accumulation was greater in vascular graft projection than other parts of the blood vessel and liver. Results. The sighs of active disease were found in 19 patients (86%) (16 male, three female) at the level of implanted vascular grafts: six aortobifemoral (27%), four aortoiliac (18.2%), four of abdominal aorta (18.2%), two of thoracic aorta (9.1%), two femoral (9.1%), one femoropopliteal (4.5%) (SUVmax 7.9 + 2.4). Two patients were considered true and one false negative- due to antibiotic usage, which reduces FDG uptake. PET/CT helped in treatment alteration of 12 patients, seven (31.8%) started new medicament therapy, five (22.7%) had a surgical graft replacement. Overall sensitivity of this method is 95%, specificity 100%, positive predictive value 100%, negative predictive value 66.6%, accuracy 95.4%. Conclusion. 18F-FDG PET/CT is a useful diagnostic method in detection of active vascular graft infection with high diagnostic accuracy, which is important in avoiding unnecessary surgery and appropriate therapy planning.