Thin-section CT finding in 250 volunteers: Assessment of the relationship of CT findings with smoking history and pulmonary function test results

PURPOSE: To evaluate the frequency and morphologic characteristics of air t rapping in volunteers with various smoking habits. MATERIALS AND METHODS: Two hundred fifty volunteers (133 women, 117 men; me an age, 39 years), including 144 smokers, 47 ex-smokers, and 59 non-smokers , prospectively underwent inspiratory and expiratory high-spatial-resolutio n computed tomography (CT) and pulmonary function tests (PFTs). The frequen cy and characteristics of air trapping were evaluated according to the popu lation's smoking habits and PFT results. RESULTS: The overall frequency of air trapping was 62% (155 of 250 subjects ). Lobular air trapping was depicted in 117 (47%) of 250 subjects, without significant differences among smokers (n = 91), ex-smokers (n = 33), and no nsmokers (n = 31) (P = .118). Segmental and lobar air trapping (38 [15%] of 250) were more frequent among smokers (24 [26%] of 91) and ex-smokers (nin e [27%] of 33) (P < .001). No relationship was found between air trapping a nd functional indexes of small-airway disease when the CT pattern of air tr apping was considered. The strongest relationship between CT abnormalities and functional alterations at the small-airways level was between inspirato ry CT features of bronchiolitis: ground-glass opacity, ill-defined micronod ules, bronchiolectasis, and air flow at low lung volumes. CONCLUSION: Whereas a significant relationship was observed between segment al and lobar air trapping and cigarette consumption, lobular air trapping w as not found to reflect functional impairment at the small-airways level.