Regional bronchodilator response assessed by computed tomography in chronic obstructive pulmonary disease

Respiratory impedance is correlated with airway narrowing in asthma using three‐dimensional computed tomography

“…In contrast to Ai, WT had only a very weak correlation with both spirometry and respiratory impedance, and the clinical importance remains unclear. Several studies reported a correlation between WT and spirometry; however, these studies did not consider potential confounding factors in the correlation analyses. Similarly, in the current study, WT significantly correlated with spirometric parameters in Spearman's rank correlation analyses without adjustments for confounding factors (Table ), as was the case for Ai (Table ).…”

“…Computed tomography (CT) of the chest can provide information on airway structural changes in asthma . Following recent advances in imaging technology, quantitative CT analyses can provide detailed airway information . Airway changes based on quantitative CT analyses are associated with impaired spirometry in asthmatic patients; however, the correlation between respiratory impedance and CT‐based airway changes is unknown.…”

“…[17][18][19][20] Following recent advances in imaging technology, quantitative CT analyses can provide detailed airway information. [21][22][23][24][25][26][27] Airway changes based on quantitative CT analyses are associated with impaired spirometry in asthmatic patients [17][18][19]21 ; however, the correlation between respiratory impedance and CT-based airway changes is unknown. Understanding the association between respiratory impedance and structural airway changes may aid asthma management.…”

Regional lung deflation with increased airway volume underlies the functional response to bronchodilators in chronic obstructive pulmonary disease

“…Chest computed tomography (CT) is a common imaging technique used to analyze the local structures that pulmonary function tests have difficulties in detecting (Hackx et al, 2015;Hasegawa et al, 2009;Hoshino & Ohtawa, 2014;Shimizu et al, 2015Shimizu et al, , 2016Yasui et al, 2013). For example, the heterogeneity of emphysema between the upper and lower regions of the lung affects pulmonary function independently of the whole-lung emphysema severity (Boueiz et al, 2018;Fuseya et al, 2018;Ju et al, 2014;Nakano et al, 1999;Tanabe, Muro, Tanaka, et al, 2012).…”

“…For example, the heterogeneity of emphysema between the upper and lower regions of the lung affects pulmonary function independently of the whole-lung emphysema severity (Boueiz et al, 2018;Fuseya et al, 2018;Ju et al, 2014;Nakano et al, 1999;Tanabe, Muro, Tanaka, et al, 2012). In the assessment of bronchodilator responses, CT measurements can reveal regional changes in the airway lumen diameter (Shimizu et al, 2015) and pharmacological volume reductions of the entire lung and within lung lobes (De Backer et al, 2012;Vos et al, 2016).…”