Comparison of mild-to-moderate chronic obstructive pulmonary disease and asthma with quantitative CT / 中国医学影像技术

ABSTRACT

Objective: To investigate the differences of proximal airway structure and CT pulmonary function between steady mild-to-moderate chronic obstructive pulmonary disease (COPD) and asthma patients. Methods: Thirty patients with mild-to-moderate COPD (mtmCOPD group), 30 patients with mild-to-moderate asthma (mtmAs group) and 30 healthy controls (normal control group) underwent low-dose paired inspiratory and expiratory CT scans and quantitative analysis. The differences of airway parameters, emphysema index and air trapping index were analyzed among 3 groups. Results: The mean lumen area (LA)/ body surface area (BSA) of the proximal airway of both mtmCOPD group and mtmAs group ([10.93±2.58]mm2/m2, [10.81±3.20]mm2/m2) were lower than that of normal control group ([12.56±2.98]mm2/m2), and statistically significant difference was found between mtmAs group and normal control group (P=0.04). The mean WA% of both mtmCOPD group and mtmAs group ([63.02±2.34]%, [63.85±2.48]%) were higher than that of normal control group ([61.55±3.54]%), while statistically significant difference was observed between mtmAs group and normal control group (P<0.01). The paired inspiratory and expiratory VI-910 (%) and VI-950 (%) of mild-to-moderate COPD were higher than those of healthy controls (all P<0.01). The expiratory absolute value of mean lung density (MLD), expiratory VI-856 (%) and MLD E/I of mtmCOPD group were also higher than those of normal control group (all P<0.05). There was no significant difference in airway structural parameters, emphysema nor air trapping index between mtmCOPD group and mtmAs group. Conclusion: The lumen area of proximal bronchus of mild-to-moderate COPD and asthma patients were both smaller than that of healthy controls to a certain extent. Meanwhile, their percentage of proximal airway wall area were both larger than that of healthy controls, which were more obviously in patients with mild-to-moderate asthma. There were obvious emphysema and air trapping in mild-to-moderate COPD patients than in healthy subjects.