CT Scan (General)
(Computed Tomography Scan; Computed Axial Tomography; CAT Scan)
by Krisha McCoy, MS
A CT scan uses x-ray technology to take views of the inside of the body. It can take clearer and more detailed pictures than regular x-rays.
Reasons for test
CT scans are used to:
Problems are rare, but all procedures have some risk. Your doctor will go over problems that may happen, such as:
If you are given a contrast dye, you may have an increased risk of problems if you also have:
You are exposed to some radiation during a CT scan. It can raise your lifetime risk of cancer. This risk raises the more times you are exposed. Pregnant woman and children are at higher risk. CT scans are usually not advised for pregnant women.
Talk to your doctor about these risks before the test.
What to Expect
Prior to Test
Description of the Test
You will lie (usually on your back) on a mobile bed. The bed will slide into the donut-shaped CT scanner. An IV line may be placed in your hand or arm. Salt water and contrast material may be injected into the IV during the test. The technologist will leave the room. Staff will talk to you using an intercom. The machine will take a series of pictures of the part of your body that is being studied. Your bed may move slightly between pictures.
You will need to wait for the technician to review your images. More images may need to be taken.
How Long Will It Take?
About 10-15 minutes. It will take longer if more pictures need to be taken.
Will It Hurt?
You may feel warm and flushed if contrast material is injected into your vein.
The CT images will be sent to a radiologist who will study them. Your doctor will get the results and talk about them with you.
Call Your Doctor
Call your doctor if you have:
If you think you have an emergency, call for emergency medical services right away.
NIH Clinical Center
Radiology Info—Radiological Society of North America
Canadian Association of Radiologists
Canadian Radiation Protection Association
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: 5/15/2018
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