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, such as through the lungs, 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Skull X-rays have largely been replaced by CT scans.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:
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.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
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).
How It Feels
You will feel no discomfort from the X-rays. The X-ray table may feel hard and the room may be cool. You may find that the positions you need to hold are uncomfortable or painful, especially if you have an injury.
There is always a slight risk of damage to cells or tissue from being exposed to any radiation, including the low levels of radiation used for this test. But the risk of damage from the X-rays is usually very low compared with the potential benefits of the test.
For example, the radiation exposure from a chest X-ray is about equal to the natural radiation exposure received during a round-trip airline flight from Boston to Los Angeles (Montreal to Vancouver) or 10 days in the Rocky Mountains (Denver, Colorado).
A skull X-ray is a series of pictures of the bones of the skull. In an emergency, the doctor can see the initial results of a skull X-ray in a few minutes. Otherwise, a radiologist usually has the official X-ray report ready the next day.
What Affects the Test
Reasons you may not be able to have the test or why the results may not be helpful include:
What To Think About
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