Abstract
Rationale: A reduction in airway visibility is a computed tomography (CT) feature in COPD, but its clinical relevance is not fully understood. This study examines whether the volume of visible airway lumens is associated with symptoms and lung functions and can be changed in response to a bronchodilator in COPD.
Methods: CT indexes, lung function and the COPD Assessment Test (CAT) were cross-sectionally examined in 147 males with COPD, and an effect of long-acting anticholinergic bronchodilator was assessed in 37 males who underwent CT scans before and 1 year after starting tiotropium treatment. A whole airway tree was identified by segmenting the lumens automatically with SYNAPSE VINCENT software (FUJIFILM Medical, Japan). The portions of the tree in right upper (RUL) and middle-lower (RMLL) lobes were extracted and their volumes were measured separately. Ratios of these volumes to the right lung volume (AWV%) were used as airway visibility indexes because the lumen volume was influenced by the natural size of airways and inspiration level at CT scan.
Results: In cross-sectional data, decreases in AWV% for RUL and RMLL were correlated with decrease in FEV1, and increases in residual volume to total lung capacity ratio and the CAT score (p<0.05). In longitudinal data, AWV% for RUL and RMLL increased after tiotropium treatment (p<0.01). These changes in AWV% were greater in subjects with substantial improvement in FEV1 than those without (p<0.05).
Conclusions: This airway visibility index reflects symptoms and lung function, and enables assessing regional bronchodilator responses in upper and middle-lower lobes in COPD.
Footnotes
Cite this article as: European Respiratory Journal 2018 52: Suppl. 62, OA3794.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2018