Abstract:

Objective　To investigate the quantitative detection of dual phase chest computed tomography (CT) in smokers and non-smokers and its correlation with lung structural injury. Methods　A total of 150 smokers who underwent dual phase chest CT scans and lung function tests at Yan'an University Affiliated Hospital from January 2023 to January 2024 were selected as the study group (112 males and 38 females); the age ranged from 51 to 76 (63.45±9.17) years; the smoking amount (nicotine intake) was 396 to 1 949 (1 387.95±197.38) mg per year. At the same time, subjects with normal lung function and no smoking history were selected as the control group (50 cases), including 38 males and 12 females; the age ranged from 50 to 74 (60.14±10.85) years. The quantitative CT indicators [normal area (Normal%), emphysema area (Emph%), small airway injury area (fSAD%), average lung density during exhalation (MLD-EX), average lung density during inhalation (MLD-IN), percentage of inhalation phase pixels<950 Hu (IN-950%), percentage of exhalation phase pixels<856 Hu (EX-856%)], and lung function [peak expiratory flow (PEF), forced expiratory volume in one second (FEV1), forced vital capacity (FVC), percentage of forced expiratory volume in one second relative to predicted value (FEV1%), FEV1/FVC] were compared between two groups. Independent sample t test was used for statistical analysis. The Pearson correlation analysis was used to investigate the relationship between CT quantitative indicators and lung function. Results　There was no statistically significant difference between the two groups in terms of MLD-IN and IN-950% (both P>0.05). The MLD-EX and Normal% values in the study group were lower than those in the control group, while the fSAD%, Emph%, and EX-856% values were higher than those in the control group (all P<0.05). There was no statistically significant difference in FEV1 and FVC between the two groups (both P>0.05). The PEF, FEV1%, and FEV1/FVC values of the study group were all lower than those of the control group (all P<0.05). The Pearson correlation analysis results showed that Normal% was positively correlated with FEV1/FVC and PEF (r=0.496, 0.365, both P<0.05); MLD-EX was positively correlated with PEF and FEV1/FVC (r=0.478, 0.319, both P<0.05); EX-856% was negatively correlated with FEV1/FVC and PEF (r=0.352, 0.484, both P<0.05); fSAD% was negatively correlated with PEF, FEV1/FVC, and FEV1% (r=-0.457, 0.581, 0.326, all P<0.05); Emph% was negatively correlated with PEF and FEV1/FVC (r=-0.564, -0.429, both P<0.05). Compared with MLD-EX and EX-856%, Normal%, Emph%, and fSAD% have a stronger correlation with lung function. Conclusion　For both smokers and non-smokers, the quantitative detection of fSAD% and Emph% indicators using dual phase chest CT has a high sensitivity in evaluating changes in lung function.

Key words: Dual phase chest CT,  , Quantitative detection,  , Lung structural injury,  , Correlation, 　Smoker

摘要：

目的　研究吸烟者和非吸烟者双气相胸部计算机断层扫描（CT）定量检测及其与肺结构损伤的相关性。方法　选取2023年1月至2024年1月在延安大学附属医院接受双气相胸部CT扫描及肺功能检查的吸烟者作为研究组（150例），男112例，女38例；年龄51～76（63.45±9.17）岁；吸烟量（尼古丁摄入量）396～1 949（1 387.95±197.38）mg/年。同期选取肺功能正常且不吸烟的受试者作为对照组（50例），男38例，女12例；年龄50～74（60.14±10.85）岁。比较两组CT定量指标［正常区（Normal%）、肺气肿区（Emph%）、小气道损伤区（fSAD%）、呼气相平均肺密度（MLD-EX）、吸气相平均肺密度（MLD-IN）、吸气相<950 Hu像素占比（IN-950%）、呼气相<856 Hu像素占比（EX-856%）］、肺功能［呼气峰流速（PEF）、第1秒用力呼气容积（FEV1）、用力肺活量（FVC）、第1秒用力呼气容积占预计值百分比（FEV1%）、FEV1/FVC］。采用独立样本t检验进行统计学分析。采用Pearson相关性分析CT定量指标与肺功能的关系。结果　两组MLD-IN、IN-950%比较，差异均无统计学意义（均P>0.05）。研究组MLD-EX、Normal%均低于对照组，fSAD%、Emph%、EX-856%均高于对照组（均P<0.05）。两组FEV1、FVC比较，差异均无统计学意义（均P>0.05）。研究组PEF、FEV1%、FEV1/FVC均低于对照组（均P<0.05）。Pearson相关性分析结果显示，Normal%与FEV1/FVC、PEF均呈正相关（r=0.496、0.365，均P<0.05）；MLD-EX与PEF、FEVI/FVC均呈正相关（r=0.478、0.319，均P<0.05）；EX-856%与FEV1/FVC、PEF均呈负相关（r=0.352、0.484，均P<0.05）；fSAD%与PEF、FEV1/FVC、FEV1%均呈负相关（r=-0.457、0.581、0.326，均P<0.05）；Emph%与PEF、FEV1/FVC均呈负相关（r=-0.564、-0.429，均P<0.05）。与MLD-EX、EX-856%相比，Normal%、Emph%、fSAD%与肺功能的相关性更强。结论　对于吸烟者和非吸烟者，双气相胸部CT定量检测fSAD%、Emph%指标，在评估肺功能改变方面具有较高的敏感性。

关键词: 双气相胸部CT, 定量检测, 肺结构损伤, 相关性, 吸烟者