Virtual Colonoscopy

Colorectal cancer is the 2nd leading cause of cancer deaths, but is 95% preventable if adults over 50 years old get screened by one of several methods, including virtual colonoscopy. Currently, only 30% of adults are screened.

The American Cancer Society recommends that all adults be screened for colorectal cancer by the age of 50 by one of several screening methods. These screening methods look for polyps and other indications of cancer within the colon and rectum.

Virtual colonoscopy, also known as CT colonography, is a newer colorectal cancer screening method that uses gentle colon cleansing and inflation and a CT scan to view the inside of the colon. Sophisticated computer software combines the CT images to form a three dimensional image of the colon, similar to what is seen during a conventional colonoscopy. A virtual colonoscopy does not require the insertion of a long tube through the colon as a conventional colonoscopy does. Additionally, the colon does not need to be filled with liquid barium as it does for a barium enema. Consequently, a virtual colonoscopy tends to be significantly faster and more comfortable for patients than other common screening methods.

Conventional (fiberoptic) colonoscopies have been considered the “gold standard” for colorectal cancer screening. Many studies have been conducted to compare the accuracy of virtual to conventional colonoscopies in finding tumors and polyps in the colon. Study results show that virtual colonoscopies are nearly as accurate as conventional colonoscopies at finding tumors and polyps of significant size. An additional benefit of CT colonography is that the radiologist can also see other abdominal structures in the CT scan images, which may enable him or her to identify other health problems when examining the images.

A limitation of virtual colonoscopies is the inability of the radiologist to remove a polyp during the procedure. If polyps are found, the patient must undergo a conventional colonoscopy so they can be removed. Consequently, virtual colonoscopies are most appropriate for individuals who are not at high risk for colorectal cancer and not experiencing any symptoms of colorectal cancer.

This page contains the following information about virtual colonoscopies:

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Reasons for Having a Virtual Colonoscopy

A patient may choose to have a virtual colonoscopy over a conventional colonoscopy for the following reasons:

Risks Involved in This Exam

There is the risk of x-ray exposure; however, it is well below the level that causes adverse affects.

There is occasional mild abdominal discomfort during the exam; however, the discomfort usually does not last more than 2-4 minutes.

As with all colorectal screening methods including conventional colonoscopy, there is no guarantee that a virtual colonoscopy will identify all cancers and polyps. However, it is one of the most accurate colorectal cancer screening exams currently available.

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Conditions to Let Our Doctor Know About

In advance of your exam, let your Invision Sally Jobe radiologist or technologist know if any of the following circumstances apply to you:

Insurance Coverage

Since virtual colonoscopies are a newer technique for colorectal cancer screening, they are currently not covered by insurance. Invision Sally Jobe requires payment for the exam at the time it is received.

Exam Locations

A virtual colonoscopy can be performed at the following location in the Denver, Colorado area:

Scheduling This Exam

To schedule a virtual colonoscopy, call 720-493-3700.

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Preparation Guidelines

Virtual colonoscopies require a colon cleansing. You must attend a preparation consultation before the exam to receive specific instructions. It is very important that all instructions are closely followed so the accuracy of the exam will not be affected.

What to Expect During Your Exam

You will be asked to change into a gown prior to starting the procedure. A technologist will help position you on the CT scanner table. A narrow, lubricated tube will be gently placed approximately four inches into your rectum.

You will be positioned on your back and your colon will be slowly filled with carbon dioxide through the rectal tube. The CT scanner then rapidly takes images of your abdomen. You will be repositioned onto your stomach for a second set of images. After all the images are taken, the tube is removed and you may change back into your normal clothing.

The entire procedure generally lasts about 10 minutes.

Recovering from Your Exam

You can return to your normal activities immediately after your exam.

Getting Your Exam Results

A radiologist experienced in the interpretation of virtual colonoscopies will analyze the data and results from your exam and compile a report. This report will be mailed to your physician, who will discuss the results with you. During the exam, our radiologists and technologists will be happy to answer questions about the exam procedure itself; however, they will not immediately provide you with the results of your exam.

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CT Colonography Trial Results

Invision Sally Jobe, in partnership with Rocky Mountain Gastroenterology Associates, was the only Colorado site to participate in a national study to examine the effectiveness of CT colonography (commonly known as virtual colonoscopy) compared to standard colonoscopy. The preliminary results have created a lot of interest in the benefits of virtual colonoscopy. A New England Journal of Medicine article published about another virtual colonoscopy study also supports the idea that virtual colonoscopies can be a valuable screening tool for colon cancer.

Watch a Video of This Procedure

The following two videos show pieces of a virtual colonscopy in process. These video require Microsoft Media Player.

  File Size Estimated Download
Time (56k modem)		  
Video 1
26.2 MB
65 min.
Video 2
31.6 MB
78 min.

Additional Information

The information on this page was taken in part from the following sources. Review these web sites or articles for additional information on virtual colonoscopies.

Additional Sites