Correlation Study On Airway Wall Thickness With Lung Function In Patients With Chronic Obstructive Pulmonary Disease Assessed By HRCT

Objective: To study the correlation between the thickness of airway and lung function in patients with COPD.Methods: High-resolution CT (HRCT) scaning was performed in 14 patients with COPD and 16 healthy controls. The airway diameter (D) and lumen diameter (L) were measured at the starting site of the right apical bronchus. Thickness of airway wall (T), the ratio of airway wall thickness and airway diameter (T/D), the percentage of the airway wall area of the total cross-sectional area of the airway (WA%) and the total area of the airway wall (WA) were calculated by the formula. Lung function indicators include: the percentage of predicted forced expiratory volume in the first second (FEV₁%pre), the ratio of the first second forced expiratory volume to forced vital capacity (FEV₁/FVC), forced mid expiratory flow (FEF_25-75%), the ratio of residual volume to total lung capacity (RV/TLC), airway resistance (RaW). The correlation between the HRCT measurements and the lung function were assessed by SPSS software.Results: WT, T/D, WA% and WA of COPD group were higher than the healthy group (P<0.05). There was a negative correlation between WA% and FEV₁% (r=-0.800, P=0.001), and also a negative correlation between WA% and FEF_25-75% (r=-0.824, P=0.049). However, the correlation was positive between WA% and RaW (r=0.915, P=0.000), and also between WA% and RV/TLC% (r=0.563, P=0.036). T/D was positively correlated with RaW (r=0.458, P=0.049), but there were no correlation between FEV₁%, FEV₁/FVC%, RV/TLC, FEF_25-75% and T/D. WT was positively correlated with RaW (r=0.637, P=0.014), but there were no correlation between FEV₁%, FEV₁/FVC%, RV/TL, FEF_25-75% and WT. WA was negatively correlated with FEV₁% (r=-0.322, P=0.026), but there were no correlation between FEV₁/FVC%, RV/TLC, RaW, FEF_25-75% and WA. WT, WA, T/D and WA% had no correlation with FEV₁/FVC%.Conclusions: The airway wall is thicker in COPD group than normal control group. There are correlations between WT,WA,T/D,WA% and lung function. Therefore, T, WA, T/D, WA% can be used as parameters which are sensitive in the evaluation of ariflow limitation. HRCT can be used to evaluate and follow up in patients with COPD.