What It Is
A neck CAT scan is a painless test that uses a specialized X-ray machine to make images of the soft tissues and organs of the neck, including the muscles, throat, tonsils, adenoids, airways, thyroid, and other glands. The blood vessels and upper spinal cord are also seen.
The doughnut-shaped machine circles the neck, taking pictures to provide cross-sections of its internal structures from various angles. These pictures are sent to a computer that records the images. It can also put them together to form three-dimensional (3-D) images. CAT scans (also called CT scans or computed axial tomography scans) are done by medical technicians.
Why It's Done
A neck CAT scan can detect signs of disease in the throat and surrounding areas. Doctors may order a neck CAT scan to look for signs of an infection (such as an abscess), a birth defect, cysts, or tumors.
Preparation
Your child may be asked to remove all clothing and accessories and change into a hospital gown because buttons, zippers, clasps, or jewelry might interfere with the image.
Your child may have to avoid eating and drinking anything for a few hours before the scan so his or her stomach is empty. Fasting is required if your child has to be sedated or needs to receive a contrast solution, which highlights certain parts of the body so doctors can see more detail in specific areas of the CAT scan.
If you suspect that your daughter is pregnant, it's important to tell the technician or doctor because there's a small chance that the radiation from the CAT scan may harm the developing baby. But if the CAT scan is necessary, precautions can be taken to protect the fetus.
Procedure
The scan itself can usually be completed in about 10 minutes. The total time depends on the age of the patient, whether contrast solution is given, and whether sedation is needed. Actual exposure to radiation is much shorter.
Your child will enter a special room and lie down on his or her back on a narrow table. A pillow and sometimes a soft brace holds the head and neck in place to prevent movement that would result in a blurry image.
If contrast solution is required, it may be given in the radiology area through an IV that will be placed in your child's hand or arm. Placing the IV will feel like a quick pinprick, and the solution is painless as it goes into the vein. Otherwise, your child may be given a special fluid to drink before the procedure. Some kids don't like the taste, but it can be flavored to make it more appealing.
The technician will position your child, then step behind a wall or into an adjoining room to operate the machine, viewing your child through a window. The technician will speak to your child through an intercom. You'll be able to stay in the CAT scan room with your child until the test begins and possibly during the test. If you leave the room, you'll join the technician in the outer room or you might be asked to sit in a waiting room. If you stay with the technician, you'll be asked to wear a lead apron to protect certain parts of your body.
Sedation may be required if a child can't lie still for the scan, which is common among infants and young kids. Sedation medicines are given through an IV line to help keep patients comfortable during the CAT scan.
When the procedure begins, the table moves through the hole in the center of the CAT scan machine. Older kids may be asked to hold their breath for a few seconds at a time to prevent the images from being blurred.
What to Expect
Your child won't feel anything as the CAT scan is taken, but may hear whirring and buzzing as the machine works. The room may feel cool due to air conditioning used to maintain the equipment. Some kids may feel uncomfortable lying still for extended periods.
After the scan is complete, your child will be asked to wait a few minutes so the technician can review the quality of the images. If they're blurred, parts of the CAT scan may need to be redone. If your child required sedation, it will take a little while for the medicine to wear off.
Getting the Results
The CAT scan images will be looked at by a radiologist (a doctor specially trained in reading and interpreting X-ray images). The radiologist will send a report to your doctor, who will discuss the results with you and explain what they mean.
Results are usually ready in 1-2 days. If the CAT scan was done on an emergency basis, the results can be made available quickly. In most cases, results can't be given directly to the patient or family at the time of the test.
Risks
In general, CAT scans are very safe, although more radiation is required than in a regular X-ray. Any exposure to radiation poses some risk to the body, but the amount used in an individual CAT scan procedure isn't considered dangerous. It's important to know that technicians use the minimum amount of radiation required to get the best results.
If your daughter is pregnant, there's a risk of harm to the developing baby, so precautions must be taken.
Contrast solutions are generally safe, with a very low incidence of allergic reactions. Talk with your doctor if you have any concerns about a possible allergy.
If your child requires sedation, there's a slight chance of slowed breathing due to the medications. If there are any problems with the sedation, the CAT scan staff will treat them right away.
Helping Your Child
You can help your child prepare for a neck CAT scan by explaining the test in simple terms before the procedure. You can describe the room and the equipment that will be used, and reassure your child that you'll be close by. For older kids, be sure to explain the importance of keeping still so the scan can be completed quickly and parts of it don't have to be repeated.
If You Have Questions
If you have questions about why the neck CAT scan is needed, speak with your doctor. You can also talk to the CAT scan technician before the procedure.
Reviewed by: Kate M. Cronan, MD
Date reviewed: January 2009
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