HIGH-RESOLUTION COMPUTED TOMOGRAPHY ANALYSIS OF AIRWAY WALL THICKNESS IN CHRONIC SMOKERS: A CROSS-SECTIONAL STUDY FOR EARLY DETECTION OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE

Abstract

Background: Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of morbidity and mortality worldwide, and is frequently diagnosed only after substantial, often irreversible, structural lung damage has occurred. Chronic cigarette smoking drives airway remodeling well before spirometric abnormalities become apparent, creating a window for imaging-based early detection.

Objective: To quantitatively compare airway wall thickness (AWT) on high-resolution computed tomography (HRCT) between chronic smokers and non-smokers, and to evaluate the utility of HRCT-derived airway measures as an early imaging biomarker for COPD.

Methods: This cross-sectional, observational study enrolled 120 participants (84 smokers, 36 non-smokers) at the Department of Radiology, Jinnah Hospital, Lahore, and Victoria Hospital, Bahawalpur, using non-probability convenience sampling. Demographic data, smoking history, respiratory symptoms, and environmental/occupational exposures were recorded with a structured questionnaire. HRCT was used to measure airway wall thickness in the right upper, left upper, right lower, and left lower lobes, and to assess emphysema, air trapping, and mosaic attenuation. Data were analyzed in SPSS v27 using independent-samples t-tests, Mann-Whitney U tests, and correlation/regression analyses, with p<0.05 considered significant.

Results: Airway wall thickness was consistently greater in smokers than non-smokers across all four lobes: right upper lobe (1.91 ± 0.90 mm vs. 1.24 ± 0.50 mm), left upper lobe (1.90 ± 0.94 mm vs. 1.20 ± 0.46 mm), right lower lobe (1.91 ± 0.91 mm vs. 1.25 ± 0.61 mm), and left lower lobe (1.89 ± 0.90 mm vs. 1.23 ± 0.59 mm). Smokers also reported more respiratory symptoms and showed a higher prevalence of emphysema, air trapping, mosaic attenuation, and more severe COPD by GOLD classification; 63.9% of non-smokers had no evidence of COPD compared with only 25.0% of smokers. Demographic and anthropometric characteristics were comparable between groups, indicating that smoking exposure, rather than age or body composition, best explained the observed airway differences.

Conclusion: HRCT-derived airway wall thickness reliably distinguishes chronic smokers from non-smokers and correlates with symptom burden and COPD severity, supporting its role as a non-invasive imaging biomarker for the early, pre-spirometric detection of smoking-related airway disease