Virtual Colonoscopy
Frequently Asked Questions
Cancer of the colon and rectum, often referred to as colorectal cancer, is the second most common cause of cancer deaths in the United States. The American Cancer Society estimates that 147,500 new cases of colorectal cancer will be diagnosed and over 57,000 Americans will die from the disease this year. Men and women are affected in equal numbers. When precancerous colon polyps are found and removed, the cancer can be prevented. When colorectal cancer is diagnosed and treated before it has spread, it is highly curable. The bad news is that only one third of colorectal cancers are currently found at an early stage.
The American Cancer Society along with other scientific groups recommends that asymptomatic, average-risk adults be screened periodically for polyps and colorectal cancer beginning at age 50 years. People at high risk because of personal or significant family history of colorectal polyps or cancer should begin screening at an earlier age.
UVA Health System currently provides Virtual Colonoscopy, a new screening test for polyps and colorectal cancer that may improve the odds of early colorectal cancer and polyp detection by making screening examinations more acceptable to patients and more affordable.
What is Virtual Colonoscopy?
What is a CT (computed tomography) Scanner?
How is Virtual Colonoscopy Different from Traditional Colonoscopy?
What Should I Expect?
What Preparation is Required?
How Accurate is VC?
Are There any Risks?
What About Needle Sticks and Intravenous Contrast Agents?
Sedation?
Does My Insurance Cover the Cost?
Getting the Test Results
How Can I Schedule a Virtual Colonoscopy?
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Virtual Colonoscopy (VC), which is also known as CT colonography, is the newest screening test for colorectal cancer. High-quality Virtual Colonoscopy is presently available at only a few centers in the country. This test uses a helical CT (computed tomography) scanner to make images of the large intestine (colon and rectum). Special computers and software convert this two-dimensional information into a three-dimensional image of the large intestine that a radiologist can scan for abnormal growths.
What is a CT (computed tomography) Scanner?
A CT scanner is a special x-ray machine combined with a computer that produces cross-sectional images or "slices" of any part of your body. Unlike a standard "flat" x-ray image where some body structures overlap others, a CT scan shows structures within each slice on a three-dimensional plane. As a result, the doctor who views a CT scan can see your entire anatomy.
The CT scan machine is open around you, does not touch you and is not confining. It should not be confused with an MRI scanner that is more of a tunnel-type structure. Even patients who suffer with claustrophobia find CT scans to be relatively fast and easy.
How is Virtual Colonoscopy Different from Traditional Colonoscopy?
With traditional colonoscopy, a slender, flexible tube about the thickness of a finger is inserted into the rectum and is advanced thorough the entire colon. The tube is connected to a video camera and light source so the physician can examine the inside of the colon. An advantage of traditional colonoscopy is that any discovered tumors can be removed or biopsied during this procedure. The patient is given a sedative before the procedure to reduce worry and discomfort. Afterwards, the patient must wait for the sedative to wear off. Another driver must accompany the patient to provide safe transportation home. The patient usually misses a day of work. Total time required in the endoscopy suite is 1 1/2 to 2 hours.
With Virtual Colonoscopy, a small tube the size of a soda straw is inserted into the rectum, and the colon is filled with carbon dioxide gas to make it easier to view. The patient may feel mild abdominal cramping and fullness, but most find the procedure more comfortable than a traditional colonoscopy. No sedative is required, so the patient can go home or back to work immediately after the procedure. There is no requirement to come with a driver. Total time required in the CT area is about 30-45 minutes.
You will be registered at the Radiology Reception Desk and will be directed to the CT Waiting Room. You will be taken from there to a dressing room and asked to remove your clothing and put on two hospital gowns, one opening in front and the other in back. From there, you will be taken to the CT scanner room and placed on a table. You will have a tiny tube inserted into your rectum and your colon will then be filled with carbon dioxide which will enable your colon to be seen in the CT images. We use carbon dioxide rather than air to fill the colon because it is quickly absorbed and eliminated from the body which prevents most abdominal cramping and bloating after the test is completed.
A Virtual Colonoscopy test takes about 15 minutes of the patient’s time in the CT scanner room. During that time, you will be asked to lie very still on a table that moves in and out of a round opening called a "gantry". The ring inside the gantry contains an x-ray tube mounted on one side and receptors mounted on the opposite side. As the x-ray tube moves around you, the receptors on the opposite side measure the amount of x-ray that passes through you. These measurements are fed into a computer that processes the information and produces images on a video screen for a radiologist to view.
Excellent bowel preparation is critical for obtaining excellent diagnostic test results. The preparation for a Virtual Colonoscopy begins 2 days before the examination. The bowel preparation involves taking a liquid diet for one day, using laxatives to remove all stool (feces) from the colon, and swallowing contrast agents to tag any remaining stool or liquid so that it can be electronically removed by the computer.
All of the required preparation materials and instructions will be available at the Radiology Reception Desk at UVA Hospital for you to pick up. After your exam is scheduled, you need to pick up your prep materials and instructions at least 3 days before your study. These are provided at no cost. Should you need the prep kit mailed to you, please call Jamie Weathersbee at (434) 243-9296. Be sure to allow at least 1-2 weeks for mailing.New scientific reports indicate that the accuracy of Virtual Colonoscopy is comparable to traditional colonoscopy when performed with multiple-detector CT scanners, computer equipment and software like those used at the University of Virginia Health System. A recent article in the New England Journal of Medicine reported that the two tests were equally sensitive for detecting growths that were 6 mm or greater in size. At this size, a cancerous or precancerous growth is considered highly treatable. If Virtual Colonoscopy detects a significant polyp, traditional colonoscopy will be required for further investigation and polyp removal. However, traditional colonoscopy is necessary in fewer than 1/3 of patients that undergo Virtual Colonoscopy.
VC has not been studied for use in evaluating inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis.
The risks with VC are minor. They include radiation exposure, which is less than with a traditional barium enema or an abdominal and pelvic CT scan. Bowel perforation has been reported in 1 in 20,000 procedures as compared with standard colonoscopy which has a risk of 1 in 1,000 bowel perforations.
What About Needle Sticks and Intravenous Contrast Agents?
No needle sticks are necessary for Virtual Colonoscopy. You will not receive any IV injections for this type of CT Scan. There is no risk of allergy to a sedative medication or intravenous x-ray “dye” (contrast agent).
You will not require any sedation or anesthesia for this test.
Does My Insurance Cover the Cost?
Because the procedure is new, it is not covered by many insurance plans when used for cancer screening. At UVA, the all-inclusive charge for Virtual Colonoscopy is $1,100.00’s and payable at the time of the procedure. If you have a documented medical reason for this procedure, it may be covered by your insurance, but you will need to check in advance with your insurance carrier.
Once we have obtained all of the CT scan "slices" and viewed them on the computer screen, the images will be transferred to a 3-D workstation for the radiologist to view and interpret. He will then send a written report to the doctor who requested the test. That doctor will in turn discuss the results with you.
How Can I Schedule a Virtual Colonoscopy?
The UVA Health System has performed Virtual Colonoscopy for two years in a research setting and now offers it to the public as a diagnostic test. Appointments can usually be scheduled within two weeks. For an appointment, please have your doctor's office call 434-243-6888.Call: Jamie Weathersbee (434)243-9296