Low-dose multislice CT and high-resolution CT assessment of pulmonary emphysema in public school teachers

Although rates of emphysematous change in smokers have previously been reported, the precise effects of smoking on emphysematous change have yet to be established because the study subjects of previous reports were heterogeneous in background, and particularly in their professions. This study was prospectively designed to determine the incidence of emphysematous change identified by low-dose multislice computed tomography (LMCT) as well as high-resolution CT (HRCT) imaging in public school teachers. We prospectively examined a series of 859 public school teachers (all males, age = 31-61 years) who had undergone LMCT and HRCT scanning during healthcare examinations. In addition, the subjects' replies to a questionnaire concerning smoking were also collected. Furthermore, most underwent a pulmonary function test. Of the 859 subjects, emphysematous change was found by LMCT imaging in 54 subjects and by HRCT in 75 subjects. All of these subjects were smokers. The FEV(1)/FVC and FEV(1)% predicted were significantly lower for subjects with PE compared with those for subjects without PE. Our study clearly demonstrated the incidence of emphysematous change in smokers in accordance with age.