Quantitative Assessment of Global and Regional Air Trappings Using Non-rigid Registration and Regional Specific Volume Change of Inspiratory/Expiratory CT Scans: Studies on Healthy Volunteers and Asthmatics

This study aimed to compare air trapping in healthy volunteers and asthmatics using pulmonary function tests and quantitative data from paired inspiratory and expiratory CT scans. ΔSV, representing the ratio of air fraction released after exhalation, was measured and used to calculate air trapping indexes. The study included 16 healthy volunteers and 9 asthmatics. The results showed significantly higher mean ΔSV, ΔSV0.4, and ΔSV0.5 values in asthmatics compared to healthy volunteers. Asthmatics also exhibited higher ΔSV values in the posterior lung. Air trapping indexes correlated negatively with clinical parameters in asthmatics. The ΔSV maps revealed abnormal geographic patterns in some asthmatic patients. The study concluded that quantitative assessment of ΔSV can differentiate the extent of air trapping between healthy volunteers and asthmatics. AVIEW COPD was used for data analysis in this study.