Pulmonary changes among asymptomatic smokers using high-resolution computed tomography and pulmonary function tests

Objective
To detect pulmonary changes among asymptomatic smokers using an inspiratory and expiratory high-resolution computed tomography (HRCT) and pulmonary function tests (PFT). Pulmonary changes associated with smoking are now an increasing public health concern. Computed tomography, especially HRCT, is the best choice for visualizing lung morphology.


Patients and methods
The study was a cohort study conducted at Shebeen Chest Hospital from January 2019 to January 2021. The study was carried out on 120 adult males; 80 of them were asymptomatic smokers and 40 matched healthy nonsmokers served as the control group. All underwent routine chest radiograph, PA view, HRCT (inspiratory, expiratory) film, and PFTs in the form of forced expiratory vital capacity (FVC), forced expiratory volume after 1 s (FEV1), FEV1/FVC, mean forced expiratory flow, and peak expiratory flow. Comparison between the two groups was done according to HRCT and PFT.


Result
There was significant difference between inspiratory and expiratory HRCT regarding air trapping between cases. Inspiratory air trapping was present in 4% while expiratory air trapping was present in 18%. There was highly significant difference between cases and controls regarding emphysema and bronchial thickening, subpleural line. There was no statistically significant difference between the two groups regarding FVC, forced expiratory flow 25–75, and FEV1/FVC, while there was a significant difference between them regarding PFT pattern results (P<0.05).


Conclusion
HRCT is the most sensitive imaging modality for diagnosing early emphysema in asymptomatic smokers. HRCT of the lung can detect lung abnormalities noninvasively.