CT Scanning

What is CT scanning?

CT scanning, also called computed or computerized tomography, is an x-ray test used for diagnosis. X-rays are taken from a series of different angles and arranged by a computer to show a cross-sectional view of organs in the body.

When is it used?

CT scanning is used when your health care provider needs more detailed information than regular x-rays provide. CT scans are especially useful for identifying tumors and cysts.

How do I prepare for a CT scan?

No preparation is necessary unless your health care provider gives you special instructions. For example, if you are having a CT scan of your abdomen or pelvis, you should not eat solid food for several hours before the scan.

Before the test, remove any jewelry you are wearing.

What happens during the procedure?

CT scanning can be done in either a hospital or mobile unit. You will lie down on a moving table, which will slide you into the scanner. The scanner can move around you to change the angles of the x-rays.

Inside the scanning machine, multiple x-ray beams are passed very quickly through your body at different angles. The images are projected onto a TV screen and prepared for your health care provider to examine.

A solution of dye (also called contrast) may be injected into a vein, or you may be asked to swallow the solution. This allows the scanner to show abnormal areas as the dye passes through your body.

Scans may last 15 to 90 minutes. They are painless, but you may tire of lying on the machine if the scan takes more than a few minutes. You can talk to the technologist at any time during the procedure. If you become panicky, the procedure may be stopped. Your health care provider may recommend a mild sedative to help you relax.

What happens after the procedure?

Rarely some people have an allergic reaction to the dye that is used for some scans. After a CT scan that uses dye, watch for signs of delayed reaction to the dye. These signs include itching, rash, sweating, or trouble breathing. Drink plenty of fluids to rid the body of the dye.

What are the benefits of this procedure?

A CT scan provides detailed pictures to help your health care provider diagnose your problem.

What are the risks associated with this procedure?

In this procedure your body is exposed to a very small amount of radiation. Exposure to radiation can be dangerous if you are exposed to it often or in large amounts. However, the amount of radiation you receive in a CT scan is less than you might receive in many other x-ray tests.

If you are pregnant, you should not have a CT scan without first discussing the possible risks with your health care provider.

There is a small risk that you will have an allergic reaction to the dye. For example, there is a chance you will be allergic to the dye if you have a shellfish allergy. Even if you are not allergic to the dye, the dye may cause warm feelings, a flushed face, headache, or a salty taste in the mouth. Rarely, it can cause nausea and vomiting.

Be sure to tell your health care provider if you know you are allergic to any medicines or chemicals such as iodine.

When should I call my health care provider?

Call your health care provider right away if:

You have a worsening of the pain or other symptoms you had before the test.

Call your provider during office hours if:

You have questions about the procedure or its result.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIA File TST5116F.HTM Release 9.0/2006