What is a skull X-ray?
X-rays use invisible electromagnetic energy beams to make images of the skull. Standard X-rays are done for many reasons, including diagnosing tumors, infection, foreign bodies, or bone injuries.
X-rays use external radiation to produce images of the body, its organs, and other internal structures to diagnose a problem. X-rays pass through body tissues onto specially treated plates (similar to camera film). It makes a "negative" type picture is made. The more solid a structure is, the whiter it appears on the film. Computers and digital media may be used in place of films.
When the body undergoes X-rays, different parts of the body allow varying amounts of the X-ray beams to pass through. Images are produced in degrees of light and dark, depending on the amount of X-rays that penetrate the tissues. The soft tissues in the body (such as blood, skin, fat, and muscle) allow most of the X-ray to pass through and appear dark gray on the film. A bone or a tumor, which is denser than the soft tissues, allows few of the X-rays to pass through and appears white on the X-ray. At a break in a bone, the X-ray beam passes through the broken area and appears as a dark line in the white bone.
While X-rays of the skull are not used as often as in the past, due to the use of newer technologies such as computed tomography (CT scans) and magnetic resonance imaging (MRI), they are still helpful for looking at the bones of the skull for fractures and detecting other conditions of the skull and brain.
Bones of the skull
The skull, also called the cranium, is the bony structure of the head. Two sets of bones comprise the skull:
Cranial bones. Bones that protect and enclose the brain.
Facial bones. Bones that provide the framework for the face and mouth.
All bones making up the skull are attached to each other by immovable joints, except for the jaw bone, which is attached via a movable joint.
The cranium holds and protects the brain. It is made up of 8 bones. They are:
- Frontal bone
- Parietal bones (one on each side)
- Temporal bones (one on each side)
- Ethmoid bone
- Sphenoid bone
- Occipital bone
The skeleton of the face has 14 bones, which include those that make up the jaws, cheeks, and nasal area.
Why might I need a skull X-ray?
X-rays of the skull may be done to diagnose fractures of the bones of the skull, birth defects, infection, foreign bodies, pituitary tumors, and certain metabolic and endocrine disorders that cause bone defects of the skull. Skull X-rays may also be used to find tumors, check the nasal sinuses, and detect calcifications within the brain.
There may be other reasons for your healthcare provider to recommend an X-ray of the skull.
What are the risks of a skull X-ray?
You may want to ask your healthcare provider about the amount of radiation used during the procedure and the risks related to your particular situation. It is a good idea to keep a record of your radiation exposure, such as previous scans and other types of X-rays, so that you can inform your healthcare providers. Risks associated with radiation exposure may be related to the cumulative number of X-ray exams or treatments over time.
If you are pregnant or think you may be, tell your provider. Radiation exposure during pregnancy may lead to birth defects. If it is necessary for you to have a skull X-ray, special precautions will be made to minimize the radiation exposure to the fetus.
There may be other risks depending upon your specific medical condition. Be sure to discuss any concerns with your healthcare provider before the procedure.
What happens during a skull X-ray?
An X-ray may be done on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your healthcare provider's practices.
Generally, an X-ray procedure of the skull follows this process:
- You will be asked to remove any clothing, jewelry, hairpins, eyeglasses, hearing aids, or other metal objects that might interfere with the procedure.
- If you are asked to remove clothing, you will be given a gown to wear.
- You will be positioned on an X-ray table that carefully places the part of the skull that is to be x-rayed between the X-ray machine and a cassette containing the X-ray film.
- Body parts not being imaged are covered with a lead apron (shield) to avoid exposure to the X-rays.
- The radiologic technologist will ask you to hold still in a certain position for a few moments while the X-ray exposure is made.
- If the X-ray is being done to find an injury, special care will be taken to prevent further injury. For example, a neck brace may be applied if a cervical spine fracture is suspected.
- Some skull X-ray studies may require several different positions. It is extremely important to remain completely still while the exposure is made, as any movement may distort the image and even require another X-ray to be done to get a clear image of the body part in question.
- The X-ray beam will be focused on the area to be photographed.
- The radiologic technologist will step behind a protective window while the image is taken.
While the X-ray procedure itself causes no pain, moving the body part being examined may cause some discomfort or pain, particularly in the case of a recent injury or invasive procedure such as surgery. The radiologic technologist will use all possible comfort measures and complete the procedure as quickly as possible to minimize any discomfort or pain.