The clinical value of 18F-FDG PET/CT dual-time-point imaging in diagnosing aortic graft infection / 中华胸心血管外科杂志

ABSTRACT

Objective:To explore the diagnostic value of 18F-deoxyglucose (FDG) PET/CT dual-time-point imaging (DTPI) in the diagnosis of aortic grafts infection (AGI). Methods:Forty-two patients with suspected AGI were prospectively recruited in this DTPI study from October 2014 to October 2021. There were 35(83%) males and 7 females, mean age (54±15) years old, range 22-79 years old. PET/CT image quality was scored as 5 grading scale. Semi-quantitative analysis of DTPI data was performed using maximum standardized uptake value (SUVmax) of suspected AGI lesions. The percentage of SUVmax change between initial and delayed images were recorded as retention index (RI). Management of Aortic Graft Infection Collaboration (MAGIC) criteria were used as the diagnostic reference criteria for AGI.Results:According to the MAGIC criteria, 27 patients (64%) were positive for AGI, and 15 patients (36%) were negative. The mean RI of AGI was higher than that of non-AGI ones[(26.7±18.9)% vs. (6.4 ±18.8)%, P<0.01]. The sensitivity, specificity, and accuracy of initial SUVmax ≥6 with the presence of AGI was 88.9%, 73.3%, and 83.3%, respectively. Delayed SUVmax ≥6 improved the sensitivity (96.3%) and accuracy (88.1%) for diagnosing AGI. DTPI with 15% increment as the optimal cut-off value of RI improved the specificity (93.3%) and accuracy (90.5%) for diagnosing AGI. Fifteen (56%, 15/27) AGI patients had improved image quality grading on the delayed images, leading to more accurately delineating the detailed extent of the infected aortic graft. Conclusion:18F-FDG PET/CT DTPI has better diagnostic performance for AGI than conventional Single-time-point PET/CT imaging by improving image quality as well as enhancing delineation of infected aortic graft extent.