A computed tomography (CT) scan of the cervical spine makes cross-sectional pictures of the neck. It uses x-rays to create the images.
You will lie on a narrow table that slides into the center of the CT scanner.
Once you are inside the scanner, the machine's x-ray beam rotates around you. (Modern "spiral" scanners can perform the exam without stopping.)
A computer creates separate images of the body area, called slices. These images can be stored, viewed on a monitor, or printed on film. Three-dimensional models of the cervical spine can be created by adding the slices together.
You must be still during the exam. Movement can cause blurred images. You may need to hold your breath for short periods of time.
The scan takes 10 to 15 minutes.
Some exams use a special dye, called contrast that is put into your body before the test starts. Contrast helps certain areas show up better on the x-rays.
Contrast can be given in different ways:
If contrast is used, you may also be asked not to eat or drink anything for 4 to 6 hours before the test.
Let your health care provider know if you have ever had a reaction to contrast. You may need to take medicines before the test to avoid this problem.
Before having the contrast, tell your provider if you take the diabetes medicine metformin (Glucophage). You may need to take extra steps before the test if you take this drug.
Too much weight can cause damage to the scanner's working parts. Find out if the CT machine has a weight limit if you weigh more than 300 pounds (135 kilograms).
You will wear a hospital gown during the study. You will need to take off all jewelry.
Some people may have discomfort from lying on the hard table.
Contrast given through an IV may cause a slight burning feeling, a metal taste in the mouth, and a warm flushing of the body. These feelings are normal and go away in a few seconds.
CT makes detailed pictures of the body very quickly. The test may help look for:
Results are considered normal if the cervical spine looks OK.
Abnormal results may be due to:
Risks for CT scans include:
CT scans expose you to more radiation than regular x-rays. Having many x-rays or CT scans over time may raise your risk for cancer, but the risk from any one scan is small. Talk to your provider about this risk and how it weighs against the benefits of the test.
Some people have allergies to contrast dye. Let your provider know if you have ever had an allergic reaction to injected contrast dye.
Rarely, the dye may cause a life-threatening allergic response called anaphylaxis. If you have any trouble breathing during the test, you should notify the scanner operator immediately. Scanners come with an intercom and speakers, so the operator can hear you at all times.
Reviewed By: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.