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 Skull X-rays have largely been replaced by computed tomography (CT) scans.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Skull X-rays have largely been replaced by CT scans.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 do not need to do anything 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).