CT Colonography
Procedure
(Computed Tomography Colonography; Virtual Colonoscopy)
Definition
CT colonography is a radiology test that looks at the colon (large intestine).
Reasons for Test
This test is done to look for polyps or colon cancer.
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Possible Complications
This procedure is safe. Rarely, a person may be allergic to the contrast material that is sometimes used.
What to Expect
Problems to Look Out For
Call your doctor if you have any problems, such as:
- Nausea
- Itching
- Problems breathing
If you think you have an emergency, call for medical help right away.
Prior to Test
The surgical team may meet with you to talk about:
- Any allergies you may have
- Current medicines, herbs, and supplements that you take and whether you need to stop taking them before the procedure
- Fasting before surgery, such as avoiding food or drink after midnight the night before
- Whether you need a ride to and from the procedure
- Cleansing the bowel before the procedure
Description of the Test
You will be on your back on a movable x-ray table. A small tube will be inserted into your rectum. Air will be gently pumped through the tube. The table will move slowly through the donut-shaped CT scanner. You will need to remain still. You will also be asked to hold your breath for periods during the scan. The test will then be repeated with you lying on your stomach.
After Test
You will be able to leave after the test is done. You can go back to your normal diet and activities.
How Long Will It Take?
30 to 40 minutes
Will It Hurt?
You may feel cramping and bloating. You may also feel the urge to pass stool.
Results
A specialist will review the images. A follow-up exam or more testing may be needed.
American College of Gastroenterology
National Institute of Diabetes and Digestive and Kidney Diseases
CANADIAN RESOURCES:
Canadian Association of Gastroenterology
Canadian Cancer Society
American College of Gastroenterology
National Institute of Diabetes and Digestive and Kidney Diseases
CANADIAN RESOURCES:
Canadian Association of Gastroenterology
Canadian Cancer Society
References
- Bryce C, Bucaj M. CT Colonography for colorectal cancer screening. Am Fam Physician. 2021;103(1):55-56.
- CT colonography. Radiology Info—American College of Radiology website. Available at: https://www.radiologyinfo.org/en/info/ct_colo.
- Scalise P, Mantarro A, et al. Computed tomography colonography for the practicing radiologist: A review of current recommendations on methodology and clinical indications. World J Radiol. 2016;8(5):472-483.
- Virtual colonoscopy. EBSCO DynaMed website. Available at: https://www.dynamed.com/procedure/virtual-colonoscopy.
Contributors
- Daniel A. Ostrovsky, MD
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