Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.
Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.
Respir Res. 2024 Nov 10;25(1):404. doi: 10.1186/s12931-024-03032-5.
Little is known about whether central airway morphological changes beyond traction bronchiectasis develop and affect clinical outcomes in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to compare central airway structure comprehensively between patients with IPF, subjects with interstitial lung abnormality (ILA), and those without ILA (control) using computed tomography (CT). We further examined the prognostic impact of IPF-specific CT airway parameters in patients with IPF.
This retrospective study included male patients with IPF, and male health checkup subjects divided into those with ILA and control based on lung cancer screening CT. Using an artificial intelligence-based segmentation technique, the extent of fibrotic regions in the lung was quantified. After airway tree segmentation, CT parameters for central airway morphology, including the lumen area of the extrapulmonary airways (LA), wall and lumen area of the segmental/subsegmental intrapulmonary airways (WA and LA), tracheal distortion (tortuosity and curvature) and bifurcation angle of the main carina, were calculated.
There were 106 patients with IPF, 53 subjects with ILA, and 1295 controls. Multivariable models adjusted for age, height and smoking history revealed that LA and WA were larger in both ILA and IPF, and that tracheal tortuosity and curvature were higher in IPF, but not in ILA, than in the control, whereas the bifurcation angle did not differ between the 3 groups. According to multivariable Cox proportional hazards models including only patients with IPF, increased WA was significantly associated with greater mortality (standardized hazard ratio [95% confidence interval] = 1.58 [1.17, 2.14]), independent of the volume of fibrotic regions, normal-appearing regions, or the whole airway tree in the lung.
Increased lumen area and wall thickening of the central airways may be involved in the pathogenesis of ILA and IPF, and wall thickening may affect the prognosis of patients with IPF.
特发性肺纤维化（IPF）患者除牵拉性支气管扩张外，中央气道形态学改变是否发生并影响临床结局知之甚少。本研究旨在通过计算机断层扫描（CT）比较 IPF 患者、间质性肺异常（ILA）患者和无 ILA 患者（对照组）的中央气道结构。我们进一步研究了 IPF 特定 CT 气道参数对 IPF 患者预后的影响。
这项回顾性研究纳入了男性 IPF 患者和男性健康体检者，根据肺癌筛查 CT 将体检者分为 ILA 患者和对照组。使用基于人工智能的分割技术，定量肺纤维化区域的程度。气道树分割后，计算中央气道形态的 CT 参数，包括肺外气道（LA）的内腔面积、肺内段/亚段气道（WA 和 LA）的壁腔面积、气管扭曲（迂曲和弯曲）和主隆突的分叉角。
共纳入 106 例 IPF 患者、53 例 ILA 患者和 1295 例对照组。多变量模型调整年龄、身高和吸烟史后显示，ILA 和 IPF 患者的 LA 和 WA 均增大，而 IPF 患者的气管迂曲和弯曲程度高于对照组，但 ILA 患者的气管迂曲和弯曲程度与对照组无差异，而 3 组间的分叉角无差异。根据仅包括 IPF 患者的多变量 Cox 比例风险模型，WA 增加与死亡率升高显著相关（标准化风险比[95%置信区间]为 1.58[1.17，2.14]），与纤维化区域、正常外观区域或整个肺气道树的体积无关。
中央气道内腔面积增大和壁增厚可能参与 ILA 和 IPF 的发病机制，壁增厚可能影响 IPF 患者的预后。
