Virtual Colonoscopy is not painful per se, but it is a little uncomfortable when the air is pumped into the colon. The abdominal camps or gas pains only last a few seconds. After the procedure, one may pass a lot of gas.
How long will the exam take?
The actual scanning takes a few minutes but the paper work and the preparation takes time. Be prepared to send about 30 minutes. Today's, newer version of Ct scans can perform scanning in less than 2 minutes.
Are there any guidelines for reporting of CV results?
Yes the procedure is standardized both in performance and in reporting.
What happens if a segment of the colon is not visualized?
In such cases, you will be told about it and one can have another Virtual Colonoscopy the following year or go for a conventional colonoscopy.
What happens after a lesion is detected on Virtual Colonoscopy?
Anytime a mass in the colon is seen, you will be notified and further management will be discussed. Reporting of polyps' = 5 mm is generally not done. They are frequently non-cancerous or, if adenomatous, have an extremely low malignant potential or probability of containing invasive cancer. All large masses greater than 10 mm will be further evaluated with conventional colonoscopy for a biopsy.
How sensitive is virtual colonoscopy?
Recent data indicate that Virtual Colonoscopy is as sensitive as conventional colonoscopy for detection of polyps greater than 10 mm.
What can affect the sensitivity of Virtual Colonoscopy in detection of polyps?
The presence of diverticular disease, complex folds in the bowel, poorly cleansed bowel and inadequately distended bowel can all lead to missed polyps.
What else can be seen with Virtual Colonoscopy?
The good thing about Virtual Colonoscopy is that the CT scan may also identify any other disorders that may be present in the liver, kidney, and adrenals and the blood vessels. The images may not be optimal but may provide a clue to the presence of other lesions.
Virtual colonoscopy may also identify other causes of internal bleeding, causes of diarrhea and can even be used to monitor the course of inflammatory bowel disease.
Who reads the Virtual Colonoscopy results?
Unlike a conventional colonoscopy which is reported by a gastroenterologist, Virtual Colonoscopy is done by a radiologist. The results are read by a board-certified radiologist who will review your CT images. If prior arrangements were made with the radiologist, the results may be available on the same day, but in most cases the reports are mailed in 48-72 hours. When a lesion has been detected in the colon or in the event of a positive test, the report will be sent to your referring physician at your request.
What are the benefits of a Virtual Colonoscopy compared to a conventional colonoscopy?
- Virtual Colonoscopy takes only 10-15 mins to complete compared to 30-45 mins for regular colonoscopy.
- There is no sedation required and the procedure is not associated with any pain.
- The procedure is minimally invasive.
- In Virtual Colonoscopy , a small plastic tube is inserted into the rectum and the bowels are dilated with carbon dioxide, whereas in colonoscopy a large flexible colonoscope is introduced.
- Virtual Colonoscopy can determine both the inner and outer surface of the colon whereas colonoscopy can only visualize the inside.
- Virtual Colonoscopy can determine the exact location of the polyp in the colon.
- There is no risk of bowel perforation.
- Occasionally the elderly and some frail patients are unable to undergo a regular colonoscopy and are better evaluated by Virtual Colonoscopy.
- In some cases, the regular colonoscopy may not fully evaluate the entire colon (due to technical or patient difficulties) and in such cases, Virtual Colonoscopy can be used on the same day (since the bowel is already prepped).
- Virtual Colonoscopy is less costly than colonoscopy.
- There is no time off from work, unlike regular colonoscopy.
What are the limitations of virtual colonoscopy?
- Because Virtual Colonoscopy does not utilize a scope, the polyps when visualized cannot be biopsied or removed.
- Any time a polyp is visualized, the individual is referred for a conventional colonoscopy for biopsy and removal. However, since most polyps less than 10 mm are rarely cancerous, not all polyps have to be referred for conventional colonoscopy. This avoids any unnecessary removal of polyps and risks associated with conventional colonoscopy.
- One other limitation of Virtual Colonoscopy is that the very small and flat polyps are not always visible with this technique. In addition, some of the flat polyps may be hidden under the folds in the colon and may not be visible. Occasionally, these flat lesions turn out to be very invasive colon cancers.
- Unlike conventional colonoscopy, Virtual Colonoscopy is associated with radiation exposure. The amount of radiation is small, but nevertheless is always a concern.
- An obese individual may not fit into the opening of a conventional CT unit.
- CT scanning is, in general, not recommended for pregnant women because of potential risk to the baby.
Because of these limitations, virtual colonoscopy has not replaced colonoscopy as the primary screening tool for individuals at normal or high risk for polyps or colon cancer. It is currently a good option for individuals who cannot or will not undergo colonoscopy.
Who should not have a virtual colonoscopy?
- Any patient with inherited syndromes of familial polyposis.
- Any patient with active bleeding in their stools.
- Any patient with active ulcerative colitis or Crohn's disease.
- Any patient with active diverticulitis (inflammation of bowel).
Is virtual colonoscopy safe?
Unlike conventional colonoscopy, Virtual Colonoscopy is very safe. Since no actual colonoscope is inserted, there is no risk of perforation, bleeding or complications related to anesthesia.
How often is follow up screening with Virtual Colonoscopy required?
- If no lesions are found during Virtual Colonoscopy, the follow up Virtual Colonoscopy can be done anytime between 3-5 years.
- For those with small polyps less than 10 mm, one can wait 1-2 years before scheduling another Virtual Colonoscopy, but colonoscopy may be a better alternative, as the lesion can be removed.
- For those elderly individuals greater than 65 years, even those with small polyps should be referred for a conventional colonoscopy and possible removal.
How much does Virtual Colonoscopy cost?
The cost of screening with Virtual Colonoscopy is variable in each State and ranges between $400 - $600.
Is Virtual Colonoscopy covered by Insurance?
Unfortunately, Virtual Colonoscopy is not covered by any Insurance plans or Medicare as it is a screening test. However, most imaging institutions can arrange for a payment plan so that one can have the screening test.