X-rays are a painless imaging process used to create pictures of the internal structures of the body. The relevant body part is exposed to a controlled amount of invisible ionizing radiation. As the x-ray beams pass through your body, they are absorbed in different amounts, depending on the density of the body part being examined. The resulting image is recorded on a digital device. This image is then viewed on a high-resolution monitor for interpretation and reviewed by a radiologist. On the x-ray image, dense materials, such as bone, show up as white, while muscle and fat appear as varying shades of gray.

For some types of x-ray tests, a contrast medium—such as iodine or barium—is introduced into your body to provide greater imaging detail.

Typically, the radiation dosage for one picture is about the same as you receive from background radiation over a 10-day period. As further protection, the technologist will often cover sensitive areas of the body, such as reproductive organs, with lead shielding, if the area is not of clinical interest.

There is no preparation for most x-rays.