Li Z, Xia Y, Fanget Y, et al. - In a large-sample low-dose CT (LDCT) lung cancer screening cohort with negative CT findings, the quantitative emphysema was assessed by subjective visual assessment. In this retrospective study, researchers included 1,231 participants with negative visual evaluation. Automatic segmentation of lungs and calculation of following indices were performed: total lung volume (TLV), total emphysema volume (TEV), emphysema index (EI), 15th percentile lung density and mean lung density. Emphysema was defined as EI ≥ 6%. Relative to women, men in higher proportion were smokers, had greater TLV, TEV, and EI. Emphysema was reported in 102 participants, accounting for 8.29%. Men vs women had greater incidence of emphysema. Findings emphasize performing CT quantitative emphysema evaluation in people older than 60 years, especially in males, which may provide more precise information, aid in the early diagnosis of emphysema and inform early intervention.