An X-ray is a form of electromagnetic radiation, just like visible light. In a healthcare setting, a machine sends individual X-ray particles, called photons, through the body. Then, a computer, or special film, is used to record the images that are created.
Structures that are dense (such as bone) block most of the X-ray particles, and they appear white in the image. Metal and contrast dye (used to highlight areas of the body) also appear white. Structures that contain air appear black and muscle, fat and fluid will appear as shades of gray in an X-ray image.
How is an X-ray performed?
The test is performed in a hospital radiology department or in your health care provider’s office, by an X-ray technologist. The type of study and area of interest will determine the position of the patient, the X-ray machine and the film. Multiple individual views may be requested.
Much like conventional photography, motion causes blurry images on radiographs. You may be asked not to move or to hold your breath during the brief exposure (about one second).
Why is the test performed?
X-ray is often used to:
- Determine whether a bone is broken
- Evaluate bone infections or joint injuries
- Diagnose and monitor arthritis or osteoporosis
- Diagnose coughs or chest pain
- Find and treat artery blockages
- Check for broken ribs or a punctured lung
- Diagnose abdominal pain
- Locate objects accidentally swallowed by a child
- Diagnose spine injuries
- Detect scoliosis and other spinal defects