by Daus Mahnke, MD
CT colonography is a radiology test that allows doctors to look for polyps or cancers of the colon. It is one of many options that can be used for colon cancer screening. The other options for colon cancer screening are:
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Each of the above options has advantages and disadvantages. The main advantage to CT colonography is that it is very safe and can be used in people who are too sick to undergo other forms of colon cancer screening (such as flexible sigmoidoscopy or colonoscopy). The main disadvantages are that it is not widely available and often is not covered by medical insurance. Also, at the present time, medical experts disagree about the effectiveness of CT colonography as a colon cancer screening tool. But, as more doctors learn how to do this test, it will become more common and more trusted.
CT colonography is one option you have for colon cancer screening. Be sure you discuss all your options for colon cancer screening with your doctor before choosing to have CT colonography.
Risk Factors for Complications During the ProcedureNone What to Expect Prior to ProcedureYou cannot eat for 8-12 hours before the procedure.You will undergo a bowel cleansing with a laxative (similar to what is needed before colonoscopy). The goal of this laxative cleansing is to rid your colon of all stool. The laxative will cause you to have many bowel movements over several hours. If you have diabetes , discuss your medications with your doctor. AnesthesiaNone Description of the ProcedureA radiologist will position you on your back on a movable x-ray table. Just before the procedure, a small tube will be inserted into your rectum. Air will then be gently pumped into your colon through this tube. The table will move slowly though the donut-shaped CT scanner. While this is happening, it is important that you lay very still. You will be asked to hold your breath during the scan. The scanning procedure will then be repeated with you lying on your stomach. After ProcedureNo postprocedure recovery time is necessary. You will be allowed to leave right after the procedure. How Long Will It Take?The test will take 30-40 minutes. Will It Hurt?You may feel cramping, bloating, or the need to have a bowel movement.
Possible ComplicationsIf used, some people can have an allergic reaction to IV contrast dye. Average Hospital StayNone. The procedure is done on an outpatient basis. Postoperative CareResume your normal diet, unless told otherwise by your doctor.Resume your medications, unless told otherwise by your doctor. OutcomeIf something abnormal is seen using CT colonography, your doctor may recommend you undergo colonoscopy. Colonoscopy is necessary after CT colonography 30%-50% of the time. Call Your Doctor If Any of the Following Occurs If you were given contrast, contact your healthcare provider if you notice: NauseaItchingDifficulty breathing RESOURCES: American College of Gastroenterology (ACG)http://www.acg.gi.org National Digestive Diseases Information Clearinghousehttp://digestive.niddk.nih.gov/index.htm CANADIAN RESOURCES: Canadian Association of Gastroenterologyhttp://www.cag-acg.org Canadian Cancer Societyhttp://www.cancer.ca References: Gore RM, Levine MS. Textbook of Gastrointestinal Radiology . 2nd ed. Philadelphia: WB Saunders Company; 2000. Mulhall P, Veerappan GR, Jackson JL, et al. Meta-analysis: computed tomographic colonography. Ann Intern Med . 2005;142(8):635-650.
Yee J. Screening CT Colonography. Radiol Clin North Am . 2004;42(4):757-766. Last reviewed February 2008 by Daus Mahnke, MDPlease 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.
