Chest X-ray

What is a chest X-ray?



A chest X-ray is a radiology test that involves e
xposing the chest briefly to radiation to produce an image

of the chest and the internal organs of the chest.

An X-ray film is positioned against the body opposite

the camera, which sends out a very small dose of a radiation

beam. As the radiation penetrates the body, it is absorbed in
 varying amounts by different body tissues depending on the tissue's composition

of air, water, blood, bone, or muscle. Bones, for example, absorb much

of the X-ray radiation while lung tissue

(which is filled with mostly air) absorbs very little, allowing most

of the X-ray beam to pass through the lung.

 What is a shadow on a chest X-ray?
 Due to the differences in their composition (and,
 therefore, varying degrees of penetration of the X-ray beam),

the lungs, heart, aorta, and bones of the chest each can be distinctly

visualized on the chest X-ray. The X-ray film records these differences
to produce an image of body tissue structures and these are shadows seen
 on the X-ray. The white shadows on chest X-ray represent more dense or
 solid tissues, such as bone or heart, and the darker shadows on the chest X-ray represent air filled tissues, such as lungs.