支气管扩张是胸部计算机断层扫描 (CT) 中常见的偶然发现，但其与肺癌筛查的相关性尚不完全清楚。我们调查了患有或不患有慢性阻塞性肺病 (COPD) 的肺癌筛查参与者中支气管扩张与呼吸道症状、肺功能和肺气肿之间的关联。我们纳入了来自荷兰-比利时肺癌筛查试验 (NELSON) 的 3260 名（戒烟者）吸烟者）。胸部放射科医生对支气管扩张进行评分。通过独立 t 检验和多变量回归检查与肺功能（FEV1% 预测值、FEV1/FVC）、呼吸道疾病（咳嗽、呼吸困难、喘息、粘液分泌过多）和 CT 量化肺气肿（第 15 个百分位）的关系。存在于 5.4% (n = 175/3260)。患有和不患有 COPD 的受试者之间的患病率没有差异（68/1121 [5.9%] 与 109/2139 [5.1%]；p = .368）。患有支气管扩张的 COPD 受试者的 FEV1% 预测值较低（76.2% vs. 85.0%；p < .001），FEV1/FVC 较低（0.58 vs. 0.62；p< .001），且肺气肿较多（- 938 HU vs. - 930 HU；p = .001）比没有支气管扩张的 COPD 受试者高。在 COPD 受试者中，支气管扩张与较低的 FEV1% 预测 (B =  - 7.7; CI [- 12.3, - 3.3])、较低的 FEV1/FVC (B =  - 2.5; CI [- 4.3, - 0.8]) 独立相关，更多咳嗽（OR 2.4；CI [1.3，4.3]）、更多粘液分泌过多（OR 1.8；CI [1.0，3.1]）和更多呼吸困难（OR 2.3；CI [1.3，3.9]）。在没有 COPD 的患者中 (n = 2139)，支气管扩张与更多的咳嗽、粘液分泌过多和喘息相关，但与肺功能恶化无关。我们的肺癌筛查参与者中有 5.4% 存在支气管扩张，并且与更多的呼吸道症状和喘息相关。 ，慢性阻塞性肺病患者，肺功能较低，肺气肿较多。在肺癌筛查人群中，支气管扩张的患病率为5.4%，严重程度主要为轻度。除非同时存在轻度慢性阻塞性肺病，否则这一发现几乎没有临床意义。在这些受试者中，支气管扩张与肺功能降低、更多呼吸道症状和更多肺气肿有关。• 5.4% 的肺癌筛查参与者中发现支气管扩张，其中包括患有或不患有轻度慢性阻塞性肺病的（前）吸烟者。 • 在患有轻度慢性阻塞性肺病的患者中，支气管扩张与肺功能降低、更多呼吸道症状和更多肺气肿相关。 • 轻度支气管扩张的偶然发现与肺癌筛查人群的相关性不大，除非同时存在慢性阻塞性肺病。© 2023。作者获得欧洲放射学会的独家许可。

Bronchiectasis is a frequent incidental finding on chest computed tomography (CT), but its relevance in lung cancer screening is not fully understood. We investigated the association between bronchiectasis and respiratory symptoms, pulmonary function, and emphysema in lung cancer screening participants with and without chronic obstructive pulmonary disease (COPD).We included 3260 (ex-)smokers from the Dutch-Belgian lung cancer screening trial (NELSON). Bronchiectasis was scored by chest radiologists. The relationship with pulmonary function (FEV1%predicted, FEV1/FVC), respiratory complaints (cough, dyspnea, wheezing, mucus hypersecretion), and CT-quantified emphysema (15th percentile) was examined with independent t-tests and multivariate regression.Bronchiectasis was present in 5.4% (n = 175/3260). There was no difference in prevalence between subjects with and without COPD (68/1121 [5.9%] vs. 109/2139 [5.1%]; p = .368). COPD subjects with bronchiectasis had a lower FEV1%predicted (76.2% vs. 85.0%; p < .001), lower FEV1/FVC (0.58 vs. 0.62; p < .001), and more emphysema (- 938 HU vs. - 930 HU; p = .001) than COPD subjects without bronchiectasis. In COPD subjects, bronchiectasis was independently associated with a lower FEV1%predicted (B =  - 7.7; CI [- 12.3, - 3.3]), lower FEV1/FVC (B =  - 2.5; CI [- 4.3, - 0.8]), more cough (OR 2.4; CI [1.3, 4.3]), more mucus hypersecretion (OR 1.8; CI [1.0, 3.1]) and more dyspnea (OR 2.3; CI [1.3, 3.9]). In those without COPD (n = 2139), bronchiectasis was associated with more cough, mucus hypersecretion, and wheezing, but not with deteriorating lung function.Bronchiectasis was present in 5.4% of our lung cancer screening participants and was associated with more respiratory symptoms and, in those with COPD, with lower lung function and more emphysema.In a lung cancer screening population, bronchiectasis has a prevalence of 5.4% with a mainly mild severity. This finding is of little clinical relevance unless mild COPD is also present. In those subjects, bronchiectasis was associated with a lower lung function, more respiratory symptoms, and more emphysema.• Bronchiectasis was found in 5.4% of lung cancer screening participants, consisting of (ex-)smokers with and without mild COPD. • In those with mild COPD, bronchiectasis was associated with a lower lung function, more respiratory symptoms, and more emphysema. • Incidental findings of mild bronchiectasis are not very relevant in a lung cancer screening population, unless COPD is also present.© 2023. The Author(s), under exclusive licence to European Society of Radiology.