Volume of pulmonary lobes and segments in chronic obstructive pulmonary diseases calculated using newly developed three-dimensional software

The aim of this study was to measure the volume of each pulmonary segment by volumetric computed tomography (CT) data using a newly developed three-dimensional software application and to identify the differences between those with chronic obstructive pulmonary disease (COPD) and controls. CT scans of 11 COPD patients and 16 controls were included. The volume of each pulmonary segment was measured by each of two operators to evaluate the reproducibility of the software. This measured volume was then divided by the total lung volume to revise individual variations. Volumes of the right (rt) S2, rt S5, left (lt) S1 + S2, lt S3, and lt S5 were significantly larger in COPD patients than in controls (P < 0.05). Regarding the ratio of the volume of each pulmonary segment per total lung volume, the areas of rt S2 and lt S1 + S2 were significantly larger in COPD patients than in controls (P < 0.05), whereas lt S10 was significantly smaller in COPD patients than in controls (P < 0.05). We measured the volume of each pulmonary segment based on volumetric CT data using this software. In addition, we demonstrated that the upper lung volume of COPD subjects was larger than that of controls, whereas the lower lung volumes were almost the same.