Variables Early-stage group (n = 34) Progressive-stage group (n = 28) p value
CT findings
  Ground-glass opacity 22 (64.7%) 16 (57.1%) 0.543 (χ)
  Consolidation 1 (2.9%) 0 (0%) 1.000 (χ)
  Ground-glass opacity with consolidation 11 (32.4%) 11 (39.3%) 0.570 (χ)
  Reticular pattern 0 0 –
  Nodule 1 (2.9%) 0 1.000 (χ)
  Rounded opacities 10 (29.4%) 6 (21.4%) 0.475 (χ)
  Cavitation 0 0 –
  Crazy-paving pattern 8 (23.5%) 8 (28.6%) 0.652 (χ)
  Air bronchogram 8 (23.5%) 6 (21.4%) 0.844 (χ)
  Halo sign 7 (20.6%) 0 0.013 (χ)
  Bronchial wall thickening 0 0 –
  Subpleural curvilinear line 4 (11.8%) 2 (7.1%) 0.681 (χ)
  Thoracic lymphadenopathy 0 1 (3.6%) 0.452 (χ)
  Pleural effusion or thickening 1 (2.9%) 1 (3.6%) 1.000 (χ)
  Pulmonary fibrosis 0 1 (3.6%) 0.452 (χ)
  Max diameter of lesion (cm) 4.27 ± 2.66 5.83 ± 3.76 0.059
    < 1 cm 0 1 (3.6) 0.201 (χ)
    1–2.9 cm 13 (38.2%) 5 (17.9%)
    3–4.9 cm 12 (35.3%) 10 (35.7%)
    > 5 cm 9 (26.5%) 12 (42.9%)
Distribution
  Central 1 (2.9%) 1 (3.6%) 0.961 (χ)
  Peripheral 12 (35.3%) 9 (32.1%)
  Both central and peripheral 21 (61.8%) 18 (64.3%)
CT score 4.79 ± 2.76 7.79 ± 4.62 0.004
  0–5 27 (79.4%) 10 (35.7%) 0.004 (χ)
  6–10 6 (17.6%) 12 (42.9%)
  11–15 0 3 (10.7%)
  > 15 1 (2.9%) 3 (10.7%)