What are x-rays?
X-rays use invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film. Standard x-rays are performed for many reasons, including diagnosing tumors or bone injuries.
X-rays are made by using external radiation to produce images of the body, its organs, and other internal structures for diagnostic purposes. X-rays pass through body structures onto specially-treated plates (similar to camera film) and a "negative" type picture is made (the more solid a structure is, the whiter it appears on the film).
When the body undergoes x-rays, different parts of the body allow varying amounts of the x-ray beams to pass through. The soft tissues in the body (such as blood, skin, fat, and muscle) allow most of the x-ray to pass through and appear dark gray on the film. A bone or a tumor, which is more dense than the soft tissues, allows few of the x-rays to pass through and appears white on the x-ray. At a break in a bone, the x-ray beam passes through the broken area and appears as a dark line in the white bone.
How are x-rays performed?
X-rays can be performed on an outpatient basis, or as part of inpatient care.
Although each hospital may have specific protocols in place, generally, an x-ray procedure follows this process:
- The patient will be asked to remove any clothing or jewelry which might interfere with the exposure of the body area to be examined. The patient will be given a gown to wear if clothing must be removed.
- The patient is positioned on an x-ray table that carefully positions the part of the body that is to be x-rayed - between the x-ray machine and a cassette containing the x-ray film. Some examinations may be performed with the patient in a sitting or standing position.
- Body parts not being imaged may be covered with a lead apron (shield) to avoid exposure to the x-rays.
- The x-ray beam is then focused on the area to be photographed.
- The patient must be very still or the image will be blurred.
- The technician steps behind a protective window and the image is taken.
- Sometimes, various x-rays may have to be taken at different angles, such as the front and side view during a chest x-ray.
What is radiation?
Radiation used in radiology causes cells in the body to emit an electrical charge. This electrical charge is detected by the different radiologic techniques and produces an image.
Radiation during pregnancy may lead to birth defects. Always tell your radiologist or physician if you suspect you may be pregnant.
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