Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
Department of Radiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
Int J Chron Obstruct Pulmon Dis. 2020 Aug 3;15:1877-1886. doi: 10.2147/COPD.S253602. eCollection 2020.
The aim of this retrospective study was to evaluate correlations between parameters of quantitative computed tomography (QCT) analysis, especially the 15th percentile of lung attenuation (P15), and parameters of clinical tests in a large group of patients with pulmonary emphysema.
One hundred and seventy-two patients with pulmonary emphysema and chronic obstructive pulmonary disease (COPD) global initiative for chronic obstructive lung disease (GOLD) stage 3 or 4 were assessed by nonenhanced thin-section CT scans in full inspiratory and expiratory breath-hold, pulmonary function test (PFT), a 6-minute walk test (6MWT), and quality of life questionnaires (SGRQ and CAT). QCT parameters included total lung volume (TLV), total emphysema score (TES), and P15, all measured at inspiration (IN) and expiration (EX). Differences between inspiration and expiration were calculated for TLV (TLV), TES (TES), and P15 (P15). Spearman correlation analysis was performed.
CT-measured lung volume in inspiration (TLV) correlated strongly with spirometry-measured total lung capacity (TLC) (r=0.81, <0.001) and moderately to strongly with residual volume (RV), forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV)/FVC (r=0.60, 0.56, and -0.49, each <0.001). Lung volume in expiration (TLV) correlated moderately to strongly with TLC, RV and FEV/FVC ratio (r=0.75, 0.66, and -0.43, each <0.001). TES and P15 showed stronger correlations with the carbon monoxide transfer coefficient (KCO%) (r= -0.42, 0.44, both <0.001), when measured during expiration. P15 correlated moderately with KCO% and carbon monoxide diffusing capacity (DLCO%) (r= 0.41, 0.40, both <0.001). The 6MWT and most QCT parameters showed significant differences between COPD GOLD 3 and 4 groups.
Our results suggest that QCT can help predict the severity of lung function decrease in patients with pulmonary emphysema and COPD GOLD 3 or 4. Some QCT parameters, including P15 and P15, correlated moderately to strongly with parameters of pulmonary function tests.
本回顾性研究旨在评估定量 CT（QCT）分析参数，尤其是肺衰减的第 15 百分位数（P15）与肺气肿患者大量临床检查参数之间的相关性。
对 172 例肺气肿和慢性阻塞性肺疾病（COPD）全球倡议慢性阻塞性肺疾病（GOLD）3 或 4 期患者进行非增强薄层 CT 扫描，吸气和呼气时屏气，肺功能检查（PFT），6 分钟步行试验（6MWT）和生活质量问卷（SGRQ 和 CAT）。 QCT 参数包括总肺容量（TLV），总肺气肿评分（TES）和 P15，均在吸气（IN）和呼气（EX）时测量。计算 TLV（TLV），TES（TES）和 P15（P15）的吸气与呼气之间的差异。进行 Spearman 相关分析。
CT 测量的吸气时肺容量（TLV）与肺活量计测量的总肺容量（TLC）强烈相关（r=0.81，<0.001），与残气量（RV），用力肺活量（FVC）和 1 秒用力呼气量（FEV）/ FVC（r=0.60，0.56 和-0.49，均<0.001）中度相关。呼气时的肺容量（TLV）与 TLC，RV 和 FEV/FVC 比值中度相关（r=0.75，0.66 和-0.43，均<0.001）。 TES 和 P15 在呼气时与一氧化碳转移系数（KCO%）（r=-0.42，0.44，均<0.001）的相关性更强。 P15 与 KCO%和一氧化碳弥散量（DLCO%）中度相关（r=0.41，0.40，均<0.001）。 6MWT 和大多数 QCT 参数在 COPD GOLD 3 和 4 组之间有显著差异。
我们的结果表明，QCT 可以帮助预测肺气肿和 COPD GOLD 3 或 4 患者肺功能下降的严重程度。一些 QCT 参数，包括 P15 和 P15，与肺功能检查参数中度至高度相关。
