Template:Estimating pneumothorax size

Estimating Pneumothorax Size

Measuring pneumothoraxes. Line A = lung apex to cupola. Line B = interpleural distance.
  • On a conventional, upright posterior-anterior chest radiograph:
    • Very small: <1 cm interpleural distance (confined to upper 1/3 of chest) OR only seen on CT
    • Small: ≤3cm lung apex to cupola (chest wall apex) on CXR
    • Large: >3cm lung apex to cupola (chest wall apex) on CXR
3cm apex to cupola measurement is roughly equivalent to 2cm interpleural distance (at the level of the hilum)
Both roughly correlate with a 50% pneumothorax by volume