Department of Nuclear Medicine, University Hospital of Zurich / University of Zurich, Raemistrasse 100, CH-8091, Zurich, Switzerland.
Division of Infectious Diseases and Hospital Epidemiology, University Hospital of Zurich / University of Zurich, Raemistrasse 100, CH-8091, Zurich, Switzerland.
Eur J Nucl Med Mol Imaging. 2019 Jun;46(6):1359-1368. doi: 10.1007/s00259-018-4205-y. Epub 2018 Nov 13.
To evaluate the diagnostic accuracy of positron emission tomography/computed tomography with F-fluorodeoxyglucose (PET/CT), contrast-enhanced CT (CE-CT), and a combined imaging approach (CE-PET/CT) in patients with suspected vascular graft infection (VGI).
PET/CT and CE-CT were performed prospectively in 23 patients with suspected VGI. Diagnostic accuracy for PET/CT was assessed by using previously suggested cut-off points for maximum standardized uptake values (SUV) measured in the vicinity of the graft. Using a new 4-point scale for visual grading, two readers independently assessed the diagnostic accuracy for CE-CT and combined CE-PET/CT. Microbiological culture, obtained after open biopsy or graft explantation, and clinical follow-up of the patients served as the standard of reference.
Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy of PET/CT for the diagnosis of VGI was 100%, 50%, 100%, 72.2%, and 78.3%, using the most favorable SUV cut-off ≥ 4.9. Respective values for CE-CT were 100%, 50%, 100%, 72.2%, and 78.3% for reader 1, and 92.3%, 80%, 88.9%, 85.7%, and 86.9% for reader 2; while respective values for combined CE-PET/CT were 100%, 70%, 100%, 81.3%, and 86.9% for reader 1, and 100%, 80%, 100%, 86.7%, and 91.3% for reader 2. Additionally, imaging provided a conclusive clinical diagnosis in patients without graft infection (i.e., other sites of infection): five of ten patients with CE-CT, six of ten patients with PET/CT, and seven of ten patients with combined CE-PET/CT.
The diagnostic accuracy of combined CE-PET/CT in patients with suspected VGI is very high. The combination of the high sensitivity of PET/CT in detecting metabolically active foci in infection, and the high specificity of CE-CT in detecting anatomic alterations, appears to be the reason why combined imaging outperforms stand-alone imaging in diagnosing VGI and may be supportive in future decision-making of difficult cases of suspected VGI. Clinical Trials.gov Identifier: NCT01821664.
评估正电子发射断层扫描/计算机断层扫描（PET/CT）、对比增强 CT（CE-CT）以及联合成像方法（CE-PET/CT）在疑似血管移植物感染（VGI）患者中的诊断准确性。
前瞻性对 23 例疑似 VGI 患者进行 PET/CT 和 CE-CT 检查。使用先前建议的测量移植物附近最大标准化摄取值（SUV）的截断值评估 PET/CT 的诊断准确性。使用新的 4 分视觉评分法，两位读者独立评估 CE-CT 和联合 CE-PET/CT 的诊断准确性。获得开放活检或移植物切除后的微生物培养物以及患者的临床随访作为参考标准。
使用最有利的 SUV 截断值≥4.9，PET/CT 诊断 VGI 的敏感度、特异度、阴性预测值（NPV）、阳性预测值（PPV）和准确率分别为 100%、50%、100%、72.2%和 78.3%。CE-CT 对 reader1 的相应值分别为 100%、50%、100%、72.2%和 78.3%，对 reader2 的相应值分别为 92.3%、80%、88.9%、85.7%和 86.9%；而联合 CE-PET/CT 对 reader1 的相应值分别为 100%、70%、100%、81.3%和 86.9%，对 reader2 的相应值分别为 100%、80%、100%、86.7%和 91.3%。此外，影像学在无移植物感染的患者（即其他感染部位）中提供了明确的临床诊断：CE-CT 患者中有 10 例中的 5 例，PET/CT 患者中有 10 例中的 6 例，联合 CE-PET/CT 患者中有 10 例中的 7 例。
在疑似 VGI 患者中，联合 CE-PET/CT 的诊断准确性非常高。PET/CT 在检测感染中代谢活跃灶方面的高敏感度，与 CE-CT 在检测解剖改变方面的高特异性相结合，似乎是联合成像在诊断 VGI 方面优于单独成像的原因，并可能有助于未来对疑似 VGI 困难病例的决策。临床试验注册：NCT01821664。
