Physiologic and quantitative computed tomography differences between centrilobular and panlobular emphysema in COPD

Background: The purpose of this study was to define the differences between centrilobular emphysema (CLE) and panlobular emphysema (PLE) phenotypes in cigarette smokers with COPD by a combined qualitative-quantitative computed tomography (CT) analysis .
Methods: Chest CT scans of 116 cigarette smokers were visually scored by 22 chest radiologists and 29 pulmonologists in a single setting for the predominant emphysema phenotype (e.g. CLE or PLE) and automatically quantified for emphysema: percentage ratio of low attenuation area to corresponding lung area (LAA%) ≤ -950 Hounsfield Units (HU) – %LAAinsp-950; gas trapping extent and bronchial metrics (wall area % for segmental [%WAsegm] and subsegmental [%WAsubsegm] bronchi). These quantitative CT indexes were compared and related to forced expiratory volume in 1 second (FEV1), ratio of FEV1 to forced vital capacity (FEV1/FVC), and smoking history as stratified for emphysema phenotype.
Results: Although more frequent than CLE in Global Initiative for chronic Obstructive Lung Disease (GOLD) stages 3 and 4 (p = 0.01), PLE was also scored in 38.2% of combined GOLD stages 1 and 2. PLE was positively associated with %LAAinsp-950(odds ratio [OR] = 1.18, 95% confidence interval [CI]: 1.12 to 1.27,