What is the way to detect a punctured lung?

Punctured lung: Need a chest x ray to look for air in the chest cavity.

Easy: Usually is associated with trauma but it can be spontaneous as well. Sudden pain with breathing, difficulty in breathing and on the xray it will clearly show a collapsed lung with free ait in the chest cavity. If it is massive a doctor will pur a tube in the chest to let the air out. Several reasons for this to happem from simple things to more complex lung problems. Seek help!