PURPOSE: Asthma is characterized by variable airflow obstruction and airway remodeling. Multidetector CT (MDCT) is useful for the evaluation of airway wall structural changes in asthma. The objective of the study is to assess the relationship between airflow limitation and airway dimensions from the third to fifth generation bronchi in asthma using MDCT.
METHODS: Thirty-eight subjects with asthma were performed spirometry, airway hyperresponsiveness, and underwent MDCT to measure the airway wall area (WA) and luminal area (Ai), WA and Ai corrected by body surface area (BSA), from up to the fifth generation of the apical bronchus (B1) and the posterior basal bronchus (B10).
RESULTS: WA/BSA, WA percentage (WA%) and Ai/BSA in the fifth generation were significantly correlated with forced expiratory volume in 1 s (FEV1)% predicted. The correlation coefficients between WA% and FEV1% predicted improved when tracking the airways from the third to the fifth generation (r = -0.25, r = -0.40, r = -0.63 for B1; r = -0.23, r = -0.47, r = -0.69 for B10). At the generation 5, WA% was greater and Ai/BSA was smaller in severe asthma than mild-to-moderate asthma.
CONCLUSION: These results suggest that airway flow limitation in asthma is closely related to the more distal airways.
CLINICAL IMPLICATIONS: The quantitative analysis of airway dimensions using MDCT could evaluate distal airway remodeling.
DISCLOSURE: Makoto Hoshino, No Financial Disclosure Information; No Product/Research Disclosure Information