What is an X-ray?

Radiography is the imaging of body structures, or parts of the body, using X-rays. X-rays are a form of radiation (X-radiation) similar to visible light, radio waves and microwaves. X-radiation is special because it has a very high energy level that allows the X-ray beam to penetrate through the body and create an image or picture.

Plain X-rays are the simplest medical images created through X-radiation. Other tests that also use X-rays are more complicated and require the use of computers to generate a picture; for example, computed tomography (CT). Any image created using an X-ray is due to different X-radiation absorption by different structures or parts in the body. A dense structure, such as bone, absorbs a high percentage of the X-ray beam (which appears light grey on the image), whereas low-density structures, such as soft tissues, absorb a small percentage (which appears dark grey on the image). The body has many different structures of varying densities and this difference creates a picture or image.

How do I prepare for an X-ray?

No specific preparation is required for a plain X-ray.

It is important that you tell your own doctor and staff at the radiology facility where you are having the X-ray if there is any chance you might be pregnant. This is important information, as it will make a difference in the way the X-ray is carried out or a different test altogether might be required. Your safety and that of your unborn child is the number one priority.

You will usually be given a hospital gown to wear, as some clothing can make it difficult to see the images clearly. You might also need to remove certain items, such as watches, necklaces and some types of clothing that contain metal objects, such as zips.

How long does an X-ray take?

It usually takes less than 15 minutes for an entire X-ray procedure. This depends on the number of parts of your body being examined and your mobility; that is, your ability to move about, and your general health. In most cases, the area being examined needs to be viewed from different directions to obtain enough information to make the diagnosis, and this might require you to move into different positions.

For example, a simple chest X-ray on an able and willing patient could take less than 1 minute. A distressed patient needing X-rays of the whole spine, pelvis, both shoulders and both legs could take 45 minutes.

People with disabilities and children will also take longer, particularly if they find it difficult to keep still or to cooperate with or understand instructions given by the radiographer carrying out the X-ray examination.