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Skull X-rays have largely been
replaced by CT scans.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:
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
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
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
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.
The bones of the skull are
normal in size and appearance.
No foreign objects, abnormal
growths, or bone abnormalities are present.
No broken bones are
Foreign objects, such as
fragments of metal or glass, may be present.
Abnormal growths, such as
tumors, may be present.
Broken bones may be
Signs of a disease that
affects the bones of the skull may be present.
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
If you can't remain still during the test. The
pictures may not be clear.
If you have a possible neck injury. In
this case, it may not be possible to do a complete set of skull
If you have a false eye (prosthetic eye) or other
artificial or metal objects on the head. These can make a shadow on the X-ray
picture that hides part of the bones.
How this information was developed to help you make better health decisions.