Department of Radiology, CHU Montpellier, avenue Doyen Gaston Giraud, 34000 Montpellier, France; PhyMedExp Inserm U1046, UMR9214 CNRS, 34000 Montpellier, France.
PhyMedExp Inserm U1046, UMR9214 CNRS, 34000 Montpellier, France; Department of Respiratory Diseases, CHU Montpellier, 34000 Montpellier, France.
Diagn Interv Imaging. 2021 Oct;102(10):605-610. doi: 10.1016/j.diii.2021.05.011. Epub 2021 Jun 26.
The purpose of this study was to evaluate the capabilities of chest computed tomography (CT) in distinguishing between active and latent tuberculosis in patients positive for interferon-gamma release assay (IGRA) testing, and to compare the performance of CT with that of quantitative IGRA testing in a low incidence setting.
Patients with latent or active tuberculosis define by an IGRA positive test were retrospectively recruited. Sensitivity, specificity and accuracy were determined for CT variables and quantitative IGRA results. Final diagnosis of active tuberculosis was based on clinical data and microbiological culture. Univariable and multivariable analyses were performed using logistic regression model to identify CT variables associated with the diagnosis of active tuberculosis.
A total of 92 patients with positive IGRA results who underwent CT examination were included. There were 54 men and 38 women with a mean age of 53.5±18 (SD) years (range: 40-68 years). Of them, 22 patients (24%) had positive Mycobacterium tuberculosis culture and 70 (76%) had latent tuberculosis. Among CT variables, consolidation had the greatest sensitivity (77%; 95%CI: 60-95%) and "tree-in-bud" the greatest specificity (97%; 95% CI: 93-100%) for the diagnosis of active tuberculosis. At univariable analysis "tree-in-bud", splenic calcification and non-calcified lung nodules were the significant variables independently associated with active tuberculosis. At multivariable analysis, the adjusted odds ratio of "tree-in-bud" was 42.91 (95% CI: 5.62-327.42). Using an optimal threshold of 51 spots, quantitative IGRA yielded 64% sensitivity (95% CI: 44-84%) and 61% specificity (95% CI: 50-73%) for the diagnosis of active tuberculosis.
In a low incidence setting, chest CT, especially when "tree-in-bud" pattern is present, is superior to quantitative IGRA testing to identify patients with active tuberculosis among those with positive IGRA testing.
本研究旨在评估胸部计算机断层扫描（CT）在区分干扰素-γ释放试验（IGRA）阳性患者的活动性和潜伏性结核病方面的能力，并比较 CT 与定量 IGRA 在低发病率环境中的表现。
回顾性招募了由 IGRA 阳性试验定义的潜伏性或活动性结核病患者。确定了 CT 变量和定量 IGRA 结果的敏感性、特异性和准确性。活动性结核病的最终诊断基于临床数据和微生物培养。使用逻辑回归模型进行单变量和多变量分析，以确定与活动性结核病诊断相关的 CT 变量。
共纳入 92 例 IGRA 阳性结果并接受 CT 检查的患者。其中男性 54 例，女性 38 例，平均年龄 53.5±18（SD）岁（范围：40-68 岁）。其中，22 例（24%）患者分枝杆菌培养阳性，70 例（76%）为潜伏性结核病。在 CT 变量中，实变具有最高的敏感性（77%；95%CI：60-95%），“树芽征”具有最高的特异性（97%；95%CI：93-100%），用于诊断活动性结核病。单变量分析中，“树芽征”、脾脏钙化和非钙化肺结节是与活动性结核病独立相关的显著变量。多变量分析中，“树芽征”的调整优势比为 42.91（95%CI：5.62-327.42）。使用最佳阈值为 51 个斑点，定量 IGRA 对活动性结核病的诊断敏感性为 64%（95%CI：44-84%），特异性为 61%（95%CI：50-73%）。
在低发病率环境中，胸部 CT，特别是“树芽征”存在时，优于定量 IGRA 检测，可用于在 IGRA 阳性检测的患者中识别活动性结核病患者。
