Value of 18F-FDG PET/CT in diagnosis of prosthetic vascular graft infection after endovascular aortic repair / 中华核医学与分子影像杂志

ABSTRACT

Objective To study the features and clinical value of 18F-fluorodeoxyglucose (FDG) PET/CT in prosthetic vascular graft infections (PVGIs) after endovascular aortic repair (EVAR).Methods Data of 27 patients (22 males and 5 females,age range:21-77 years,average age:42 years) who underwent PET/CT imaging after EVAR from October 2011 to January 2017 were studied retrospectively.A total of 11 cases were finally diagnosed as PVGIs (PVGIs group),and the remaining 16 cases were defined as the negative group.PET/CT imaging features were compared between two groups.The detection rates of PET/CT and aortic CT angiography (CTA) for PVGIs were calculated and compared.Two-sample t test and Fisher exact test were used for data analysis.Results Significant uptake of FDG around the stents was detected by PET/CT in all patients in PVGIs group.The maximum standardized uptake value (SUVmax) of 11 patients in early imaging was 14.9±3.3 (10.8-21.8) and that of 9 patients in delayed imaging was 13.8±3.4 (10.6-19.1).Six patients of the negative group underwent the delayed imaging.No uptake or mild uptake of FDG around the stents was observed in negative group,with the SUVmax of 1.7±0.8(1.0--2.9) in early imaging and 1.6±0.7(1.1-2.5) in delayed imaging.SUVmax in negative group was significantly lower than that in PVGIs group (t values:12.6 and 11.8,both P＜0.001).Five patients in PVGIs group were diagnosed as graft infections by the aortic CTA,while the remaining 6 cases showed no definitive infection signs on aortic CTA.The detection rate of aortic CTA was 5/11,which was significantly lower than that of PET/CT (P＜0.05).In negative group,6 patients had abnormal FDG uptakes in other areas and were finally confirmed as infectious lesions (n=3) or malignant tumors (n=3).Conclusion Compared with aortic CTA,18F-FDG PET/CT is more sensitive and accurate in detection and diagnosis of PVGIs after EVAR.