Nuclear Medicine Unit, Department of Medical-Surgical Sciences and of Translational Medicine, Sant'Andrea Hospital, "Sapienza" University of Rome, 00161, Rome, Italy.
Vascular Surgery Unit, Department of Clinical and Molecular Medicine, Sant'Andrea Hospital, "Sapienza" University of Rome, 00161, Rome, Italy.
Eur J Nucl Med Mol Imaging. 2023 Sep;50(11):3235-3250. doi: 10.1007/s00259-023-06309-x. Epub 2023 Jun 27.
We aimed at comparing Tc-HMPAO white blood cells (Tc-WBC) scintigraphy, 18fluorine-fluorodeoxyglucose ([F]FDG) positron emission tomography/computed tomography (PET/CT) and CT angiography (CTA) in patients with suspected abdominal vascular graft or endograft infection (VGEI). Moreover, we attempted to define a new visual score for interpreting [F]FDG PET/CT scans aiming at increasing its specificity.
We prospectively compared Tc-WBC SPECT/CT, [F]FDG PET/CT, and CTA in 26 patients with suspected abdominal VGEI. WBC scans were performed and interpreted according to EANM recommendations. [F]FDG PET/CT studies were assessed with both qualitative (Sah's scale and new visual score) and semi-quantitative analyses. CTA images were interpreted according to MAGIC criteria. Microbiology, histopathology or a clinical follow-up of at least 24 months were used to achieve final diagnosis.
Eleven out of 26 patients were infected. [F]FDG PET/CT showed 100% sensitivity and NPV, with both scoring systems, thus representing an efficient tool to rule out the infection. The use of a more detailed scoring system provided statistically higher specificity compared to the previous Sah's scale (p = 0.049). Tc-WBC SPECT/CT provided statistically higher specificity and PPV than [F]FDG PET/CT, regardless the interpretation criteria used and it can be, therefore, used in early post-surgical phases or to confirm or rule out a PET/CT finding.
After CTA, patients with suspected late VGEI should perform a [F]FDG PET/CT given its high sensitivity and NPV. However, given its lower specificity, positive results should be confirmed with Tc-WBC scintigraphy. The use of a more detailed scoring system reduces the number of Tc-WBC scans needed after [F]FDG PET/CT. Nevertheless, in suspected infections within 4 months from surgery, Tc-WBC SPECT/CT should be performed as second exam, due to its high accuracy in differentiating sterile inflammation from infection.
本研究旨在比较 Tc-HMPAO 白细胞（Tc-WBC）闪烁扫描、18 氟-氟代脱氧葡萄糖（[F]FDG）正电子发射断层扫描/计算机断层扫描（PET/CT）和 CT 血管造影（CTA）在疑似腹部血管移植物或内植物感染（VGEI）患者中的应用。此外，我们尝试定义一种新的视觉评分方法来解读[F]FDG PET/CT 扫描，以提高其特异性。
我们前瞻性比较了 26 例疑似腹部 VGEI 患者的 Tc-WBC SPECT/CT、[F]FDG PET/CT 和 CTA。根据 EANM 建议进行白细胞扫描并进行解释。[F]FDG PET/CT 研究采用定性（Sah 量表和新的视觉评分）和半定量分析进行评估。根据 MAGIC 标准解读 CTA 图像。微生物学、组织病理学或至少 24 个月的临床随访用于获得最终诊断。
26 例患者中有 11 例被感染。[F]FDG PET/CT 具有 100%的敏感性和阴性预测值（NPV），两种评分系统均能有效排除感染，使用更详细的评分系统与之前的 Sah 量表相比具有更高的特异性（p=0.049）。Tc-WBC SPECT/CT 提供了比[F]FDG PET/CT 更高的特异性和阳性预测值（PPV），无论使用何种解释标准，因此可用于术后早期阶段，以确认或排除 PET/CT 发现。
在 CTA 后，疑似晚期 VGEI 的患者应进行[F]FDG PET/CT，因其具有较高的敏感性和 NPV。然而，由于其特异性较低，阳性结果应通过 Tc-WBC 闪烁扫描来确认。使用更详细的评分系统可减少[F]FDG PET/CT 后所需的 Tc-WBC 扫描数量。然而，对于术后 4 个月内疑似感染的患者，由于 Tc-WBC SPECT/CT 在区分无菌性炎症和感染方面具有较高的准确性，因此应作为第二检查进行。
