Emphysema in asymptomatic smokers: quantitative CT evaluation in correlation with pulmonary function tests

Abstract

Purpose: To provide quantitative information on emphysema in asymptomatic smokers in correlation with pulmonary function tests (PFT).

Patients and methods: The study population included 75 smokers (current smokers: n=39; ex-smokers: n=36) and 25 nonsmokers who underwent volumetric high-resolution CT of the chest with automated quantification of emphysema and PFTs.

Results: Current smokers had a higher percentage of emphysema in the right lung (P=0.041) and right upper lobe (P=0.037). The overall percentage of emphysema did not differ according to the Gold stage (P=0.77). Smokers with emphysema had significantly higher mean values of FRC (P=0.012), RV (<0.0001) and TLC (P=0.0157) than smokers without emphysema but no significant differences were found in neither the mean values of TLCO nor in expiratory flows (P>0.05). Correlations were found between the percentage of emphysema and (a) cigarette consumption of current (r=0.34215; P=0.0330) and ex-smokers (r=0.44104; P=0.0071); and (b) alterations of TLC, FRC, RV and DLCO of smokers.

Conclusion: Quantitative CT allows recognition of regional specificities and subclinical functional alterations in smokers with emphysema.