Here’s the original x-ray:

This patient has a partially collapsed right lung, also known as a spontaneous pneumothorax.

If you look closely, you can see that the branching blood vessels that go from the heart to the lungs have a normal pattern on his left side, starting off wide and becoming getting finer and finer as they move away from the heart until they reach the edge of the lung (and are no longer discernible).

On the abnormal right side, those branching blood vessels stop abruptly at a sharp thin vertical line, indicated by the multiple arrows. This is the edge of the collapsed lung, now pulled inwards. Note that no blood vessels extend past that vertical line on the right side.

Here are a few diagrams that explain this abnormality. The first diagram shows a normal pair of fully-expanded lungs:

The second diagram shows a partially collapsed right lung, just as in this patient. You can see the empty space (or “pneumothorax”) between the edge of the lung and the ribs:

The third diagram shows the proper treatment of a large pneumothorax — a chest tube is placed through the skin and into the pneumothorax cavity. The end of the tube outside of the patient is then attached to a suction device which removes the dead air and allows the lung to re-expand. That’s how this patient was treated:

Here’s lots more information on spontaneous pneumothorax.

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