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Background: Pulmonary damage induced by smoking acts slowly and may show no symptom until pulmonary functions are decreased.
Objectives: To correlate findings on chest X-ray (CXR), pulmonary function tests (PFTs), and thoracal high resolution computed tomography (HRCT) scans for determining whether these findings may be useful in an early diagnosis of pulmonary damage in asymptomatic smokers.
Methods: Sixty smokers were questionnaired about pulmonary symptoms. Among them 50 asymptomatic volunteers, underwent CXR, PFTs (spirometry, lung volumes and DLCO) both inspiratory and expiratory thoracal HRCT. Air trapping on HRCT scan was calculated using a visual score method. These scores were correlated with CXR and PFTs.
Results: PFTs showed an obstructive pattern in only 3(%6) of patients. FEV1/FVC values were decreased as cumulative smoking increased. FEV1 and DLCO values were significantly lower in subjects with the history of parental smoking than the other subjects. All CXRs were normal but various degrees of air trapping were seen in all patients on expiratory HRCTs. Total and mean pulmonary scores assesing air trapping were higher in the group who were smoking more than 20 packs/year. Although correlation between PFT parameters and air trapping scores was expected, this correlation was not found.
Conclusion: We concluded that even asymptomatic smokers may have pulmonary damage. The expiratory thoracal HRCT may be more useful than both CXR and PFTs in detecting air trapping as a clue for early pulmonary damage in asymptomatic smokers.