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Chest X-Ray

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Chest X-ray definition and facts

  • A chest X-ray is most commonly used to detect abnormalities in the lungs, but can also detect abnormalities in the heart, aorta, and the bones of the thoracic area.
  • Extra metallic objects, such as jewelry are removed from the chest and neck areas for a chest X-ray to avoid interference with X-ray penetration and improve accuracy of the interpretation.
  • A chest X-ray can be used to diagnose many conditions and diseases such as pleurisy, pulmonary edema, pneumonia, bronchitis, cysts, tumors, cancers, asthma, pericarditis, cardiomegaly, heart failure,  pneumothorax, and fractures.

What is a chest X-ray?

A chest X-ray is a radiology test that involves exposing 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.

How is the chest X-ray procedure performed?

Patients obtaining a chest X-ray will often be requested to use an X-ray gown, and extra metallic objects such as jewelry are removed from the chest and/or neck areas. These objects can block X-ray penetration, making the result less accurate. Patients may be asked to take a deep breath and hold it during the chest X-ray in order to inflate the lungs to their maximum, which increases the visibility of different tissues within the chest.

The chest X-ray procedure often involves a view from the back to the front of the body as well as a view from the side. The view from the side is called a lateral chest X-ray. Occasionally, different angles are added in order for the radiologist to interpret certain specific areas of the chest.

The radiology technologist or technician is a trained, certified assistant to the radiologist who will help the patient during the X-ray and actually perform the X-ray test procedure. After the chest X-ray is taken and recorded on the X-ray film, the film is placed into a developing machine, and this picture (which is essentially a photographic negative) is examined and interpreted by the radiologist.

How do doctors interpret chest X-rays?

A radiologist is a physician specialist trained to interpret images of the body produced on films. After the films are produced by the technician they are developed and reviewed by the radiologist for interpretation. After the radiologist reviews the chest X-ray, occasionally further images or angles may be necessary. Once all the films have been reviewed by the radiologist, a report is generated which is transmitted to the ordering practitioner.

In the past, the doctors interpreting the films placed the films in front of a source of light for better visualization of the shadows on the chest X-ray. This usually consisted of a fluorescent light source placed in metal box and covered by a white plastic.

More recently, newer technology has replaced this old reading technique in many health care facilities and radiology offices. This advanced technology has eliminated the need for the actual physical films to be used and placed on a light box for interpretation. The images, once taken and developed, are uploaded into a computer with special software that enables digital images to be viewed on a computer screen. The doctor can look at the images on the screen, interpret the results, and comment on the computer all within minutes after the images were taken.

Additionally, this technology allows for ability to easily look at any previous images taken from the same patient. It also essentially eliminates the possibility of lost X-rays and speeds up the interpretation of X-rays, and the communication between doctors about the results.

Medically Reviewed by a Doctor on 8/22/2016


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