呼吸气双相HRCT成像对不同COPD表型的定量评估

Quantitative analysis in different phenotypes of chronic obstructive pulmonary disease by the paired inspiratory and expiratory high resolution CT

目的:研究CT定量参数在3组慢性阻塞性肺疾病(COPD)表型中的差异及其与肺功能的相关性,确定临床可行性CT应用参数。方法 :对91例稳定期COPD患者进行呼吸气双相HRCT扫描及临床肺功能检查。根据肺气肿分级和有无支气管管壁增厚将研究对象进行分型:A型、E型和M型。分析CT定量参数(%LAA-950ins、%LAA-856exp、RVC-856to-950和E/Iratio MLD)及肺功能参数在3组COPD表型中的差异,CT定量参数与肺功能参数之间做相关性分析。结果 :本研究中A型50例,E型23例,M型18例。FEV1、FEV1%、FEV1/FVC值在A型、E型和M型组中依次减少。%LAA-950ins、%LAA-856exp、RVC-856to-950和E/I-ratio MLD值在A型、E型和M型组中依次增加。A型组中,%LAA-950ins与肺功能参数之间无相关性,%LAA-856exp、RVC-856to-950、E/I-ratio MLD分别与肺功能参数间呈负相关,且有统计学意义。其中,E/I-ratio MLD与FEV1%之间的负相关性最强(γ=-0.588,P=0.000)。E型和M型组中,各个CT定量参数与肺功能参数之间呈显著负相关(P<0.01)。RVC-856to-950与FEV1之间的负相关性最强(γ=-0.669,P=0.000)。结论 :3组COPD表型的CT定量参数不同,CT肺气肿指标(%LAA-950ins)、气体陷闭指标(%LAA-856exp、RVC-856to-950和E/I-ratio MLD)可以作为评估COPD肺功能的有效参数。

Objective： To study the differences of CT quantitative parameters in the three phenotypes of chronic obstructive pulmonary disease（COPD）, and correlations with pulmonary function parameters, so as to ascertain the clinical feasibility of CT applicative parameters. Methods： Ninety one patients with stable COPD underwent the paired inspiratory and expiratory HRCT scans and pulmonary function tests. The subjects were classified into the three phenotypes according to the rank of emphysema and with or without the bronchial wall thickening： A phenotype, E phenotype and M phenotype. The differences of pulmonary function parameters and CT quantitative parameters（% LAA-950 ins、% LAA-856 exp、RVC-856 to-950 and E/I-ratio MLD） in the three phenotypes of COPD were analyzed. The correlations between CT quantitative and pulmonary function parameters were evaluated. Results： There were three phenotypes in this study： A phenotype（n=50）, E phenotype（n=23） and M phenotype（n=18）. The values of FEV1, FEV1% and FEV1/FVC were reduced successively in the A phenotype, E phenotype and M phenotype. The values of %LAA-950 ins, %LAA-856 exp, RVC-856 to-950 and E/I-ratio MLD were increased successively in the A phenotype, E phenotype and M phenotype. In the A phenotype group, %LAA-950 ins had no correlation with pulmonary function parameters, %LAA-856 exp, RVC-856 to-950 and E/I-ratio MLD had statistically negative correlations with pulmonary function parameters separately. Among them, E/I-ratio MLD had the strongest negative correlation with FEV1%（γ=-0.588, P=0.000）. In the E phenotype and M phenotype groups, CT quantitative parameters had statistically significant negative correlations with pulmonary function parameters（P〈0.01）. RVC-856 to-950 had the strongest negative correlation with FEV1（γ=-0.669, P=0.000）. Conclusion： CT quantitative parameters were different in the three phenotypes of COPD. CT index of emphysema（%LAA-950 ins） and CT indexes of gas trapping（%LAA-856 exp, RVC-856 to-950 and E/I-ratio MLD） could be used as effective parameters for evaluating pulmonary function of COPD.