State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China.
Neusoft Medical Systems Co., Ltd, Shenyang, People's Republic of China.
Int J Chron Obstruct Pulmon Dis. 2022 Sep 14;17:2241-2252. doi: 10.2147/COPD.S362479. eCollection 2022.
Pulmonary vascular alteration is an important feature of chronic obstructive pulmonary disease (COPD), which is characterized by distal pulmonary vascular pruning in angiography. We aimed to further investigate the clinical relevance of pulmonary vasculature in COPD patients using non-contrast computed tomography (CT).
Seventy-one control subjects and 216 COPD patients completed the questionnaires, spirometry, and computed tomography (CT) scans within 1 month and were included in the study. Small pulmonary vessels represented by percentage of cross-sectional area of pulmonary vessels smaller than 5 mm or 5-10 mm to the total lung fields (%CSA<5 or %CSA5-10, respectively) were measured using ImageJ software. Spearman correlation was used to investigate the relationship between %CSA<5 and airflow limitation. A receiver operating characteristic (ROC) curve was built to evaluate the value of %CSA<5 in discriminating COPD patients from healthy control subjects. Segmented regression was used to analyze the relationship between %CSA<5 and %LAA-950 (percentage of low-attenuation areas less than -950 HU).
We found a significant correlation between %CSA<5 and forced expiratory volume in one second (FEV1) percentage of predicted value (%pred) (r = 0.564, < 0.001). The area under the ROC curve for the value of %CSA<5 in distinguishing COPD was 0.816, with a cut-off value of 0.537 (Youden index J, 0.501; sensitivity, 78.24%; specificity, 71.83%). Since the relationship between %CSA<5 and %LAA-950 was not constant, performance of segmented regression was better than ordinary linear regression (adjusted R, 0.474 0.332, < 0.001 and < 0.001, respectively). As %CSA<5 decreased, %LAA-950 slightly increased until an inflection point (%CSA<5 = 0.524) was reached, after which the %LAA-950 increased apparently with a decrease in %CSA<5.
%CSA<5 was significantly correlated with both airflow limitation and emphysema, and we identified an inflection point for the relationship between %CSA<5 and %LAA-950.
肺血管改变是慢性阻塞性肺疾病（COPD）的一个重要特征，其特征在于血管造影中的远端肺血管修剪。我们旨在使用非对比计算机断层扫描（CT）进一步研究 COPD 患者的肺血管的临床相关性。
71 名对照受试者和 216 名 COPD 患者在 1 个月内完成了问卷调查、肺功能和 CT 扫描，并被纳入研究。使用 ImageJ 软件测量代表小肺动脉的小肺动脉横截面积百分比（分别为小 5mm 或 5-10mm 以下的肺血管横截面积百分比和 5-10mm 的肺血管横截面积百分比（%CSA<5 和 %CSA5-10）。采用 Spearman 相关分析探讨%CSA<5 与气流受限的关系。构建受试者工作特征（ROC）曲线以评估%CSA<5 区分 COPD 患者与健康对照的价值。分段回归用于分析%CSA<5 与低衰减区百分比（低于-950HU 的低衰减区百分比）（%LAA-950）之间的关系。
我们发现%CSA<5 与用力呼气量（FEV1）预测值百分比（%pred）之间存在显著相关性（r = 0.564，<0.001）。%CSA<5 区分 COPD 的 ROC 曲线下面积为 0.816，截断值为 0.537（约登指数 J，0.501；敏感性，78.24%；特异性，71.83%）。由于%CSA<5 与 %LAA-950 之间的关系并非恒定，分段回归的性能优于普通线性回归（调整后的 R，0.474 比 0.332，<0.001 和 <0.001）。随着%CSA<5 的降低，%LAA-950 略有增加，直到达到拐点（%CSA<5=0.524），此后随着%CSA<5 的降低，%LAA-950 明显增加。
%CSA<5 与气流受限和肺气肿均有显著相关性，并且我们确定了%CSA<5 与 %LAA-950 之间关系的拐点。
