title: [Prevalence of emphysematous changes as shown by low-dose spiral CT screening images in 6144 healthy subjects].
abstract: We assessed the prevalence of emphysematous changes among healthy workers and retired persons, using subjective evaluations of low-dose spiral CT images obtained during thoracic CT screenings for lung cancer. Among 6144 male participants (50-69 years old; mean age, 57), we detected 686 cases (11.2%) with emphysematous changes. The majority (95.3%) of CT-detected emphysema cases were in current or former smokers, and 169 cases (24.6%) showed significant obstructive impairment. Of 236 cases with emphysematous changes in the internal region (more than 20 mm from the costal margin), 98(41.5%) had significant obstructive impairment. Smoking was found to be the major risk factor for CT-detected emphysema. Longitudinal observation of the emphysema cases, as well as health care support for cessation of smoking, is very important.
mesh_terms: D000368:Aged; D006801:Humans; D008175:Lung Neoplasms / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009098:Multiphasic Screening; D015995:Prevalence; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology; D011856:Radiographic Image Enhancement; D012129:Respiratory Function Tests; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed