Background: Airflow limitation is seen in COPD Group 0>80%, Group 1 50-80% and Group 2<50%. QCT included average lumen area of segmental bronchi corrected for body surface area (LA/BSA), mean lung density expiratory/inspiratory ratio (MLDE/I), 15 th percentile point (Perc15) 9.288.28-10.83 v11.159.56-13.04; 11.329.63-13.33,p<0.05 respectively. Perc15 is not significantly different between asthmatics with severe airflow limitation -955-966 to -949 v-958-971 to -947HU respectively, but is significantly different (p<0.05) between asthmatics with no airflow limitation 1.911.87-1.96 v1.851.78-1.92; 1.811.72-1.89,p<0.05 respectively. Conclusion: Asthmatics with moderate airflow limitation show LA/BSA narrowing compared to spirometrically similar COPD. QCT measured Emphysema may be overestimated in asthmatics with severe airflow limitation as LAC-D-950 remains different between them and COPD. Funded by AirPROM.
Hartley et al. (Mon,) studied this question.