CT Scan (General)

(Computed Tomography Scan; Computed Axial Tomography; CAT Scan)

by Krisha McCoy, MS

Definition

A CT scan uses x-ray technology to take multiple views of the inside of the body. Compared to regular x-rays, a CT scan can take clearer and more detailed images of organs, bone, soft tissue, blood vessels, and other parts of the body.

CT Scan of the Head

Reasons for test TOP

Some of the primary uses for CT scans include:

Looking for bleeding inside the body, especially in the skull
Studying the chest and abdomen
Determining the size and location of a tumor
Diagnosing skeletal problems
Diagnosing blood vessel diseases
Planning radiation treatments for cancer
Guiding biopsies and other tests
Planning surgery
Identifying injuries from trauma

Possible Complications TOP

Problems from the procedure are rare, but all procedures have some risk. Your doctor will review potential problems, like:

Allergic reaction to contrast material
Damage to the kidney from contrast material

Factors that may increase the risk of complications include:

Allergies—if you are given a contrast dye during the test
Kidney problems—if you are given a contrast dye during the test

You are exposed to some radiation during a CT scan. Radiation exposure can increase your lifetime risk of cancer. This risk increases the more times you are exposed to radiation. Radiation exposure is more concerning for pregnant women and children. CT scans are usually not advised for pregnant women.

Be sure to discuss these risks with your doctor before the test.

What to Expect TOP

Prior to Test

Before the test, your doctor will likely ask about:
- Your medical history
- Medications you take
- Allergies
- Whether you are pregnant or trying to get pregnant
Before your test, follow your doctor’s instructions regarding any changes to your medications or diet.
At the healthcare facility:
- A healthcare professional will explain the test and answer any questions you may have.
- You will remove your clothes and put on a gown or robe.
- You will remove all jewelry, hair clips, dentures, and other objects that could show on the x-rays and make the images hard to read.
- If your CT scan includes oral contrast material, you will need to drink the contrast material at this time.

Description of the Test

You will lie (usually on your back) on a movable bed. The bed will slide into the donut-shaped CT scanner. Depending on the type of scan, an IV line may be placed in your hand or arm. A saline solution and contrast material may be injected into the IV during the test. The technologist will leave the room. You will be given directions using an intercom. The machine will take a series of pictures of the area of your body that is being studied. Your bed may move slightly between pictures.

After Test TOP

You will need to wait for the technician to review your images. In some cases, more images will need to be taken.

How Long Will It Take? TOP

About 10-15 minutes, depending on how many pictures are needed.

Will It Hurt? TOP

You may feel warm and flushed if contrast material is injected into your vein. Otherwise, you should feel no pain.

Results TOP

The CT images will be sent to a radiologist who will analyze them. Your doctor will receive the results and discuss them with you.

Call Your Doctor TOP

Call your doctor if any of these occur:

Symptoms of allergic reaction, such as hives, itching, nausea, swollen or itchy eyes, tight throat, or difficulty breathing
Any other concerns

If you think you have an emergency, call for emergency medical services right away.

RESOURCES

NIH Clinical Center
https://www.cc.nih.gov

Radiology Info—Radiological Society of North America
https://www.radiologyinfo.org

CANADIAN RESOURCES:

Canadian Association of Radiologists
https://car.ca

Canadian Radiation Protection Association
http://www.crpa-acrp.ca

References:

Computed tomography (CT)—body. Radiology Info—Radiological Society of North America website. Available at:
...(Click grey area to select URL)
Updated March 16, 2016. Accessed March 13, 2018.

Radiation-emitting products: computed tomography (CT). US Food & Drug Administration website. Available at: https://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/MedicalX-Rays/ucm115317.htm. Updated March 7, 2018. Accessed March 13, 2018.

Last reviewed March 2018 by EBSCO Medical Review Board Marcie L. Sidman, MD
Last Updated: 3/18/2013

EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

To send comments or feedback to our Editorial Team regarding the content please email us at healthlibrarysupport@ebsco.com. Our Health Library Support team will respond to your email request within 2 business days.