View source for Template:Estimating pneumothorax size

===Estimating [[Pneumothorax]] Size===
[[File:Pneumothorax measurement.jpg|thumb|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''