What does the examination entail?
Virtual colonoscopy is a relatively new method for examining the large intestine (colon).  The colon is first inflated with air following which images of the large intestine are taken using computerized tomography (CT). A computer puts the images together to create an animated, three-dimensional view of the inside of the large intestine allowing us, to visually see the entire inner surface of the colon.  This procedure takes the place of a colonoscopy wherein a fiber optic camera is lead through the colon.  This procedure makes is unnecessary to ingest barium contrast material.    

When is this method used?
The procedure is used to look for signs of pre-cancerous growths, called polyps; cancer, and other diseases of the large intestine.  It may be used in screening examinations for patients who are symptom free as well as for patients whose complaints and symptoms might indicate possible polyps or cancer.  
 
What are the advantages over other types of colon examination methods?
With the inflation of air and the aid of the computer, the entire length of the colon may be viewed, not just its surface, but also its entire width, abnormalities and its relationship to its surroundings.  The process is not painful, of minimal discomfiture and is much more tolerable than colonoscopy. 

The large intestine may also be examined with a procedure called, irrigoscopy.  This is a method of radiological exploration of the digestive tract wherein barium contrast material and air is administered into the large intestines via an enema.  With this method, however, only the silhouette of the colon may be examined, since we cannot “see" beyond the walls. 

What are the disadvantages over other types of colon examination methods?
Virtual colonoscopy uses x-rays to obtain images of the colon, while in colonoscopy, the Patient is not exposed to its effects, in addition, contrast material may also be required.
In colonoscopy, a flexible instrument is guided through the large intestine all the way up to where the large and small intestines meet, making examination of the interior surface possible on the way in and on the way back.  With this method, samples may also be obtained of possible abnormal tissues and smaller abnormal growths removed.  These possibilities are not available with virtual colonoscopy.

How to prepare for a virtual colonoscopy?
The success of the examination depends largely on the extent to which the bowels were cleansed.  The preparation only takes a single day.  The day before the procedure, the patient may ingest fluids only and take a special laxative.   On the day of the procedure, no food nor drink may be ingested. 

How is the virtual colonoscopy performed?
The procedure is done in the Radiology Department in the computer tomography (CT) room.  These are usual scheduled for the morning hours so that you won't have to go hungry for long.  First, you will be given an injection (into a muscle) to loosen the intestines, then, the large intestines will be filled with air with the help of a thin enema tube.  A series of images will be prepared while you are lying on your stomach and a series with you on your back.  This is necessary because, should any liquid have remained in the colon, by moving it around, every section of the intestines will be examinable.  The administration of contrast material (into a vein) may also be necessary in some instances in order to precisely observe the intestinal walls, the changes therein and its surroundings.  The procedure itself takes 20-30 minutes.  The results should be available and the report ready and available to the patient by the following day together with a CD containing all the CT images.

When should a virtual colonoscopy not be done?

• Since the addition of air into the colon might prove dangerous in cases of active intestinal inflammation, the procedure should only be done once the inflammation is over.
• Pregnant or lactating women should not undergo this procedure due to the x-ray used.
• The procedure should also be carefully considered in the case of children due to the irradiation. 
• Elderly patients or those handicapped patients who cannot properly do all the necessary preparations should also put under careful consideration since the results might prove to be of limited value then.
• Allergies or other contraindication to the contrast material only partly would limit its use since it is not required in every case. 

What complications might there be?
There are no complications when contrast material is not used.
There might be an allergic reaction of various degrees of seriousness to the contrast material.   For this reason we urge our patients to carefully read the information material provided and the consent agreement.