Heart and mediastinum

· two thirds of the cardiac shadow lies to the left of the midline and one-third to the right

· the cardiac shadow is normally approximately one third of the chest cavity

· serial X-rays should be checked for signs of a widening mediastinum (sign of possible tamponade) and check for signs of mediastinal shift.

Lung fields

· lung markings of normal lungs are vascular shadows, which are visualised as branching grey linear shadows extending bilaterally to the edge of the chest wall.

· check that the lungs have re-expanded, and that there is no pneumothorax ( black area with no lung markings frequently visible in the apex) or haemothorax (white area with a defining line usually visible in the bases)

· increased opacities may denote pulmonary oedema, infection, collapse of lung or pleural fluid

Pleural space

A potential space only, so should not be visualised. Check for fluid or air build up in this space.

Chest tubes

Ensure no kinking of tubes

Diaphragm and stomach

Both hemidiaphragms are rounded, with the right hemidiaphragm about 2cm higher than the left.

Abnormalities

· the hemidiaphragm shadows may be obliterated indicating the adjacent tissue has become non air containing (pulmonary oedema)

· diaphragm displaced upwards (pulmonary collapse)

· diaphragm displaced downwards (pneumothorax or hyper-inflated lung)

Soft tissue

Observe for any swelling or signs of surgical emphysema