关键词: 双气相胸部CT, 定量检测, 肺结构损伤, 相关性, 吸烟者

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