High-Resolution Computed Tomography Findings in Healthy Heavy Smokers and Correlation with Pulmonary Function Tests

Abstract

Introduction: Chest radiographs and pulmonary function tests (PFTs), may show the adverse effects of smoking on the lungs, but in some cases these methods are inadequate and interpreted as normal. High-resolution computed tomography (HRCT) provides more sensitive and specific imaging features to identify parenchymal-interstitial abnormalities in the early stages of the disease related with smoking. The purpose of this study is to recognize lung HRCT findings of smoking in cigarette smokers and non-smokers and investigate whether there is a relationship with airway obstruction on PFTs. Methods: A total of 155 subjects (110 heavy smokers, 45 non-smokers) who performed both HRCT and PFTs were included in the study. Two radiologists independently evaluated the CT findings for the following characteristics: bronchiectasis, bronchial wall thickening, emphysema, atelectasis, interstitial patterns, and fibrotic changes. Afterwards, the relationship between the HRCT findings and PFTs of the heavy smokers and non-smokers was presented statistically. Results: There were statistically significant differences regarding emphysema and bronchial wall thickening between the heavy smokers and non-smokers (p = 0.001 and p = 0.000, respectively) on HRCT. Emphysema and bronchial wall thickening were more common in patients who had obstructive PFTs. Fibrotic changes, atelectasis, bronchial wall thickening, and emphysema were the most common imaging findings although normal PFTs. Conclusion: It is crucial to recognize the common imaging findings on HRCT of heavy smokers for diagnosis and treatment of smoking related lung disease. HRCT is vital in detecting the early stages of parenchymal-interstitial abnormalities of the lungs due to smoking, despite normal chest radiograms and PFTs.