CT Scan (General)
(Computed Tomography Scan; Computed Axial Tomography; CAT Scan)
A CT scan uses x-ray technology to take multiple cross-sectional views of the inside of the body. Compared to regular x-rays]]>, a CT scan can take clearer images of organs, bone, soft tissue, blood vessels, and other areas of the body.
CT Scan of the Head
Reasons for test
Some of the primary uses for CT scans include:
- Studying the chest and abdomen
- Determining the size and location of a tumor
- Diagnosing and treating skeletal problems
- Diagnosing blood vessel diseases
- Planning radiation treatments for cancer
- Guiding biopsies]]> and other tests
- Planning surgery
- Identifying injuries from trauma
Complications are rare, but no procedure is completely free of risk. If you are planning to have a CT scan, your doctor will review a list of possible complications, which may include:
- Allergic reaction to contrast material
- Damage to the kidney from contrast material
Small risk of radiation exposure.
Note: A CT scan is not usually recommended if you are pregnant.
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)
Be sure to discuss these risks with your doctor before the test.
What to Expect
Prior to Test
Before the test, your doctor will likely ask about:
- Your medical history
- Medicines you take
- Whether you are pregnant or trying to get pregnant
- Leading up to your test, follow your doctor’s instructions regarding any changes in how you take your medicines and any restrictions on your eating and drinking.
At the healthcare facility:
- A healthcare professional will explain the test and answers 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 during the test. The technologist will leave the room. She will give you directions via 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.
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?
About 10-15 minutes
Will It Hurt?
You may feel warm and flushed if contrast material is injected into your vein. Otherwise, you should feel no pain.
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
After the test, call your doctor if any of the following occurs:
- Symptoms of allergic reaction (eg, hives]]>, itching, nausea, swollen or itchy eyes, tight throat, difficulty breathing)
- Any other concerns
National Library of Medicine
Radiological Society of North America
Canadian Association of Radiologists
Canadian Radiation Protection Association
Computed tomography (CT)—body. Radiological Society of North America website. Available at: http://www.radiologyinfo.org/en/info.cfm?pg=bodyct&bhcp=1. Accessed May 29, 2007.
CT scan: a guide for patients. Department of Radiology, Brigham and Women’s Hospital website. Available at: http://brighamrad.harvard.edu/patients/education/ct/ctguide.html#q2. Accessed May 29, 2007.
Last reviewed November 2009 by ]]>Rosalyn Carson-DeWitt, MD]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © 2007 EBSCO Publishing All rights reserved.