BACKGROUND Quantitative computed tomographic (QCT) biomarkers of airway morphology hold potential for understanding and monitoring regional airway remodeling in asthmatic patients. OBJECTIVE We sought to determine whether the change in airway lumen area between total lung capacity (TLC) and functional residual capacity (FRC) lung volumes measured from CT imaging data was correlated with severe outcomes in asthmatic patients. METHODS We studied 152 asthmatic patients (90 female and 62 male patients) and 33 healthy subjects (12 female and 21 male subjects) using QCT. Postprocessing of airways at generations 1 to 5 (1 = trachea) was performed for wall area percentage, wall thickness percentage (WT%), lumen area at baseline total lung capacity (LATLC), lumen area at baseline functional residual capacity (LAFRC), and low attenuation area at FRC. A new metric (reflecting remodeling, distal air trapping, or both), Delta Lumen, was determined as follows: Percentage difference in lumen area (LATLC - LAFRC)/LATLC × 100. RESULTS Postprocessing of 4501 airway segments was performed (3681 segments in the 152 patients with asthma and 820 segments in the 33 healthy subjects; range, 17-28 segments per subject). Delta Lumen values were negatively correlated with WT% and low attenuation area (P < .01) in asthmatic patients. Delta Lumen values were significantly lower for airway generations 3 to 5 (segmental airways) in subjects undergoing hospitalization because of exacerbation and in patients with refractory asthma requiring treatment with systemic corticosteroids. WT% and low attenuation area were positively and Delta Lumen values were negatively associated with systemic corticosteroid treatment (P < .05), suggesting that a reduced Delta Lumen value is a potential outcome biomarker in patients with severe asthma. CONCLUSION Reduced Delta Lumen value in the central airways measured by using QCT is a promising exploratory biomarker of unstable refractory asthma that warrants further study.

中文翻译：

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吸气和呼气多探测器计算机断层扫描之间的流明面积变化（Delta流明），作为哮喘患者严重预后的一种度量。

背景技术气道形态的定量计算机断层摄影（QCT）生物标记物具有潜在的潜力，可用于理解和监测哮喘患者的局部气道重塑。目的我们试图确定从CT影像数据测得的总肺活量（TLC）和功能残余容量（FRC）肺容量之间的气道腔面积变化是否与哮喘患者的严重预后相关。方法我们使用QCT研究了152名哮喘患者（90名女性和62名男性患者）和33名健康受试者（12名女性和21名男性受试者）。对第1到第5代（1 =气管）的气道进行后处理，包括壁面积百分比，壁厚百分比（WT％），基线总肺活量（LATLC）处的管腔面积，基线功能残量（LAFRC）处的管腔面积， FRC的衰减面积小。确定了新的度量标准（反映了重塑，远端空气陷留或两者兼有），Delta Lumen的确定如下：内腔面积百分比差异（LATLC-LAFRC）/ LATLC×100。结果对4501个气道段进行了后处理（其中3681个段152位哮喘患者和33位健康受试者中的820个细分；范围为每个受试者17-28个细分）。哮喘患者的Delta流明值与WT％和低衰减面积呈负相关（P <.01）。对于因急性发作而住院的患者，以及需要全身性皮质类固醇治疗的难治性哮喘患者，第3至5代气道（分段气道）的Delta流明值显着较低。WT％和低衰减区域呈正相关，而Delta Lumen值与全身性皮质类固醇激素治疗呈负相关（P <.05），这表明降低的Delta Lumen值是重症哮喘患者潜在的结局生物标志物。结论使用QCT测得的中央气道Delta流明值降低是不稳定的难治性哮喘的有前途的探索性生物标志，值得进一步研究。