What is CT colonography?
CT colonography is a non-invasive, highly accurate test that allows doctors to look at the large bowel (colon) to detect polyps and cancers in the early stages. It is a screening technique that uses a CT scanner and computer graphic software to produce images of the colon through which the radiologist can “navigate.” Colon cancer can be prevented if polyps are discovered and removed early. CT colonography enables early detection of polyps and cancers.
Who should consider the procedure?
The American Cancer Society recommends patients seek colorectal cancer screening as early as age 50 and every 3-5 years thereafter. Patients with a family history of colorectal cancer or polyps should be screened more often.
Why is CT colonography an excellent alternative to conventional colonoscopy?
In conventional colonoscopy, a long thin scope is inserted into the colon (rectum). This procedure typically uses sedation for the patient’s comfort. A tiny camera in the scope transmits images of the colon to a monitor for the doctor to review. The total procedure time is 30-60 minutes. CT colonography is more comfortable than a conventional colonoscopy screening because it does not require a colon scope or sedation. CT colonography also takes less time. Another advantage of CT colonography is that organs surrounding the colon can also be screened for abnormalities. Sometimes conventional colonoscopy may result in an incomplete exam due to bowel obstructions. There is a slightly greater chance of having a complete exam with a CT colonography. A conventional colonoscopy may be needed to investigate abnormalities discovered on the virtual exam.
How should I prepare for this procedure?
This procedure requires oral preparations to clear stool from your colon. An oral contrast medium is also taken the day prior to your scan. After the scan, you can immediately return to your normal routine.
What can I expect during this procedure?
The procedure will begin by having air introduced into the colon through a small enema tip. This allows distention of the colon to enable the CT scanner to take detailed 3D images. The procedure requires you to lie comfortably on the scanning table first on your back and then on your stomach. The entire study tales approximately 15-20 minutes.