Airway and emphysema assessment by quantitative CT among emphysema phenotype of chronic obstructive pulmonary disease

Abstract Background Chronic obstructive pulmonary disease (COPD) has been a major public health problem. Although pulmonary function test remains the primary diagnostic method, quantitative computed tomography (QCT) analysis has become more significant in the assessment of COPD and is being utilized more frequently to detect and categorize emphysema. Objective The study was designed to assess airway and emphysema involvement using QCT indices in patients with pulmonary emphysema. Material and methods Ninety-four emphysema patients were included. They were divided according to the visual type of emphysema into; 39 patients of pan-lobular emphysema, 35 of centrilobular emphysema, 10 of para-septal emphysema and 10 of mixed type of emphysema. Spirometry and CT scans were done to assess indications of emphysema and airway affection, including low attenuation area (LAA% < − 950) and wall area percentage (WA%), respectively, using quantitative CT analysis software. Results Based on quantitative CT indices; %LAA < − 950 of 15% and the 75th percentile of the percentage of WA%, the emphysema patients were divided into 3 CT-definable phenotypes; airway predominant (33 patients), emphysema predominant (32 patients), and mixed airway and emphysema phenotype (29 patients). We found that the most frequent phenotype in patients with centrilobular and panlobular emphysema were mixed phenotype (65.7%) and emphysema phenotype (64.2%), respectively, with a nearby distribution of these 3 CT phenotypes in both patients of paraseptal and mixed type of emphysema. Conclusion In assessing the pulmonary emphysema phenotype of COPD, we suggest that both CT assessments of airway dimensions and emphysema are helpful and complementary, which may aid in the pharmacotherapy of these patients.