An X-ray is a quick, painless test that produces images of the structures inside your body — particularly your bones.
X-ray beams pass through your body, and they are absorbed in different amounts depending on the density of the material they pass through. Dense materials, such as bone and metal, show up as white on X-rays. The air in your lungs shows up as black. Fat and muscle appear as shades of gray.
The average X-Ray takes 10 to 20 minutes. There is no preparation necessary for X-Rays.
An X-Ray machine sends individual X-Ray particles through the body. The images are recorded on a computer or on film. 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, and muscle, fat, and fluid will appear as shades of gray.
You need to stay still when you are having an X- Ray. Motion can cause blurry images. You may be asked to hold your breath or not move for a few seconds when the image is being taken.
Before the X-Ray, tell your doctor and technician if you are pregnant, may be pregnant or if you have an IUD inserted. Metal can cause unclear images. You will need to remove all jewelry and may need to wear a hospital gown depending on the type of X-Ray needed.
X-Rays are monitored and regulated so you get the minimum amount of radiation exposure needed to produce the image. For most X-Rays, the risk of cancer or defect is very low.
Some people worry that X-rays aren't safe because radiation exposure can cause cell mutations that may lead to cancer. The amount of radiation you're exposed to during an X-ray depends on the tissue or organ being examined. Sensitivity to the radiation depends on your age, with children being more sensitive than adults.
Generally, however, radiation exposure from an X-ray is low, and the benefits from these tests far outweigh the risks.
However, if you're pregnant or suspect that you may be pregnant, tell your doctor before having an X-ray. Though the risk of most diagnostic X-rays to an unborn baby is small, your doctor may consider another imaging test, such as ultrasound.
What to wear
In general, you undress whatever part of your body needs examination. You may wear a gown during the exam, depending on which area is being X-rayed. You may also be asked to remove jewelry, eyeglasses and any metal objects because they can show up on an X-ray.
What you can expect during the X-ray
X-rays are performed at doctors' offices, dentists' offices, emergency rooms and hospitals — wherever an X-ray machine is available. The machine produces a safe level of radiation that passes through your body and records an image on a specialized plate. You can't feel an X-ray.
A technologist positions your body to obtain the necessary views. Pillows or sandbags may be used to help you hold the position. During the test, you must stay still (and sometimes hold your breath to avoid moving) to prevent blurry images.
An X-ray procedure may take from a few minutes for a bone X-ray to more than an hour for more-involved procedures, such as those using a contrast medium.
Your child's X-ray
Restraints or other techniques may be used to keep a young child still during an X-ray. These won't harm your child. They will prevent the need for a repeat procedure, which may be necessary if your child moves during the X-ray exposure.
You may be allowed to stay with your child during the test. If you do, you'll likely be asked to wear a lead apron to shield you from unnecessary exposure.
X-rays are saved digitally on computers, which can be viewed on-screen within minutes. A radiologist typically views and interprets the results and sends a report to your doctor, who then explains the results to you. In an emergency, your X-ray results can be made available to your doctor in minutes.