SPIROMETRIC GATED QUANTITATIVE COMPUTED-TOMOGRAPHY OF THE LUNG IN HEALTHY SMOKERS AND NONSMOKERS

RATIONALE AND OBJECTIVES. The authors investigated the influence of ci garette smoking on healthy, asymptomatic smokers and nonsmokers with t he help of spirometric triggered quantitative computed tomography, In our prospective study, the authors compared conventional lung function parameters with the computed tomography values (lung attenuation, lun g area). METHODS. The study group comprised 40 healthy volunteers cons isting of 20 smokers and nonsmokers (20 females and 20 males), The cor responding groups have been matched concerning their age, height, body mass, (cigarette) pack years, Computer tomography scans were triggere d at 35%, 50%, 70% and 95% of vital capacity at a defined apical and a basal level. RESULTS. Functional residual capacity (FRC), total lung capacity and airway resistance showed close correlations to lung paren chymal attenuation values especially at full inspiration and expiratio n, For example, the authors found a correlation coefficient of r = -0. 845 (P less than or equal to 0.001) concerning the FRC and lung attenu ation values in the apical lung at 35% of vital capacity in male smoke rs, Male smokers proved to have a significantly higher pulmonary lung density at all inspiratory states than the other groups (P less than o r equal to 0.05; Student's t test). Although male smokers had a higher vital capacity they showed a smaller cross-sectional area increase of the lung during inspiration than nonsmokers, This phenomenon is a res ult of the decreasing compliance of the smoker's lung, due to small ai rways disease and hypoxic vasoconstriction. CONCLUSIONS. Spirometric-t riggered quantitative computed tomography has proved to be a sensitive diagnostic device for the investigation of early pathomorphologic cha nges in healthy, asymptomatic cigarette smokers.