The Methodist Hospital System. Leading Medicine
The Methodist Hospital System. Leading Medicine

Radiology

X-ray

Offered at:

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:

  1. 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.
  2. 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.
  3. Body parts not being imaged may be covered with a lead apron (shield) to avoid exposure to the x-rays.
  4. The x-ray beam is then focused on the area to be photographed.
  5. The patient must be very still or the image will be blurred.
  6. The technician steps behind a protective window and the image is taken.
  7. Sometimes, various x-rays may have to be taken at different angles, such as the front and side view during a chest x-ray.

Radiation during pregnancy may lead to birth defects. Always tell your radiologist or physician if you suspect you may be pregnant.