CT Colonography Patient Frequently Asked Questions

Q. What is a CT Scan?

A. CT is an abbreviation for computed tomography, which is a non-invasive diagnostic medical exam that combines X-rays and computers to view the inside of the body. Often called a CAT scan, CT scans have been performed safely and successfully for almost 30 years.


Q. What is CT Colonography?

A. A CT Colonography is a type of CT Scan that helps detect abnormalities within the colon including polyps and cancers. A CT scanner takes images of the colon; then special computer software converts this information into 2D and 3D images that a radiologist can review to check for abnormal findings.


Q. Who should have a CT Colonography?

A. Your physician can determine if a CT Colongraphy is a good alternative for you. It can be especially helpful for patients with conditions that prevent them from undergoing a conventional colonoscopy.


Q. How is a CT Colonography different from a traditional colonoscopy?

A. A CT Colonography exam is faster and less invasive than a traditional colonoscopy. It does not require sedation and may eliminate the need for an internal examination of the colon.

For a Colonoscopy exam, patients usually have an intravenous line placed for the administration of a pain medication and a mild sedative to minimize any discomfort. The clinician will insert a long, flexible, lighted tube into the rectum and slowly guide it through the entire length of the colon. The tube is called a colonoscope.

For CT Colonography, no sedation is necessary. The images are obtained using a CT Scanner. During this procedure a small tube will be inserted in the rectum so the clinician can introduce air into the colon. This tube is only inserted in the rectum and is completely different in appearance and functionality than colonoscope. After the CT images are obtained the clinician will analysis the data using a special viewing software specifically designed for internal viewing of the colon. For more information on this software, please refer to the "Application Introduction Demo" under For The Medical Professional section of this web page.


Q. What do I need to do to prepare for the exam?

A. As with a traditional colonoscopy, the CT Colonoscopy requires a gentle 24-to-48 hour bowel cleansing preparation.


Q. What will happen during the exam?

A. Before the exam, you will be asked to change into a hospital gown. When you enter the CT room, you will lie on your back on the CT scan table. A thin tube will be placed in your rectum, which will introduce air into your colon. The air is necessary to inflate the bowel, allowing any polyps to be better visualized along the colon wall. You will then hold your breath while the CT scanner images your abdomen. The procedure is then repeated while you lie on your stomach. Following this, you are free to resume your normal activities.


Q. How long does it take?

A. The images are taken using a CT scanner, this process only takes about 10-15 minutes.


Q. Is it painful?

A. Some patients report a sensation of fullness, mild discomfort or temporary cramping.


Q. What happens after the exam?

A. The information from the CT scanner is sent over a network to the 3D image-processing computer. The radiologist will carefully analyze your CT images, review the findings with your physician and provide a report. Your physician will then discuss the results with you.


Q. What is Oral Contrast and why do I need to take it?

A. The purpose of oral contrast is to make certain organs or tissues more recognizable during radiological procedures. Virtual colonoscopy uses oral contrast to mark stool remaining in the colon. This helps the radiologist differentiate between stool and other abnormalities in the colon. It is very important that this medication be taken in its entirety to get the best possible results. If not taken properly the exam may have to be repeated.


Q. Any other issues I should be concerned about?

A. It's very important that you raise any questions or any other concerns you may have with your physician.