X-rays are a form of electromagnetic radiation, just like a visible light. In a health care setting, a machine sends individual x-ray particle called protons. These particles pass through the body. A computer or special film is used to record the images that are created. Structures that are dense, such as bone, will block most of the x-ray particles, and will appear white. Metal and contrast media (special dye used to highlight areas of the body) will also appear white. Structures containing air will be black an muscle, fat and fluid will appear as shades of grey.
How is this test performed?
The test is performed in a hospital radiology department or in the health care provider’s office by an x-ray technologist. The positioning of the patient, x-ray machine and the film depends on the type of study and area of interest. Multiple individual views may be requested. Patients will be asked to hold their breath or not move during the brief exposure – about 1 second.
What are the risks?
During a single radiograph, a small fraction of the x-rays pass right through the body. The remaining photons are absorbed by tissues in the body. The energy of the absorbed photons can break apart (ionize) compounds and this may cause cell damage. Most cell damage is soon repaired.