A skull X-ray is a series of pictures of the bones of the skull. Skull X-rays have largely been replaced by computed tomography (CT) scans.

X-rays are a form of radiation, like light or radio waves, that are focused into a beam, much like a flashlight beam. X-rays can pass through most objects, including the human body. X-rays make a picture by striking a detector that either exposes a film or sends the picture to a computer. Dense tissues in the body, such as bones, block (absorb) many of the X-rays and look white on an X-ray picture. Less dense tissues, such as muscles and organs, block fewer of the X-rays (more of the X-rays pass through) and look like shades of gray on an X-ray. X-rays that pass only through air look black on the picture.

A skull X-ray may help find head injuries, bone fractures, or abnormal growths or changes in bone structure or size.

Why It Is Done

Skull X-rays have largely been replaced by CT scans. A skull X-ray may be done to:

• Find fractures.
• Find a metallic foreign object stuck in the skull.
• Check problems on a baby's head, such as an odd shaped skull.

How To Prepare

Before the X-ray test, tell your doctor if you are or might be pregnant. Pregnancy and the risk of radiation exposure to your unborn baby (fetus) must be considered. The risk of damage from the X-rays is usually very low compared with the potential benefits of the test. If a skull X-ray is absolutely necessary, a lead apron will be placed over your abdomen to shield your baby from exposure to the X-rays.

You don't need to do anything else before you have this test.

How It Is Done

A skull X-ray is taken by a radiology technologist. The X-ray pictures are usually read by a doctor who specializes in interpreting X-rays (radiologist).

You will need to remove any jewelry that may be in the way of the X-ray picture. You will also need to remove glasses or dentures.

You may be asked to lie on an X-ray table or sit in a chair. The bones of the skull and face are so detailed that several views from different angles are needed. A series of X-ray pictures is usually taken from the front, back, top, and sides of your head. You should hold your head completely still while the pictures are being taken. A padded brace, foam pads, a headband, or sandbags may be used to hold your head in place while the pictures are taken.

Skull X-rays usually take about 10 to 20 minutes. You will wait about 5 minutes until the X-rays are processed in case repeat pictures need to be taken. In some clinics and hospitals, X-ray pictures can be shown immediately on a computer screen (digitally).