Virtual Colonoscopy

When should this method be used?

The method is excellent in identifying colorectal polyps and tumors in screening examinations for asymptomatic patients or for patients with complaints suggesting colorectal polyps or tumors.

Advantages over other types of colorectal examinations

When filled with air, the entire length of the inner surface of the colon is visible with the help of a special computer software.  The thickness of the entire inner wall may be examined, noting abnormalities and changes in the surrounding areas.  The examination is not painful, does not cause any discomfort and is significantly better tolerated than mirroring. 

The colon may also be examined with the irrigoscopy method.  This is an x-ray technique that requires barium enema and air pumped in through a tube.   With this method, however, only the silhouette of the colon may be seen not allowing for viewing beyond the wall.

What preparations are necessary?

The day before the examination, the patient drinks only fluids and takes a special laxative.  The day of the examination, no eating or drinking is allowed.  It is important that these instructions be followed, since the success of the examination depends on the extent to which the colon is cleansed.     

The examination procedure

The examination is performed in the computer tomography room in the radiology department, usually in the morning hours so that the patient will not have to go hungry for too long.    

The procedure takes about 20-30 minutes and does not require sedation.  The patient is asked to first lie on a table on his/her back.  Air is then pumped through a thin tube inserted in the anus and the rectum to fill the large intestine.   The table will then be moved through the CT scanner producing a series of cross-sectional images of the colon.  The procedure will be repeated with the patient lying face down.  In some cases, contrast material may be necessary (administered through the vein) to more precisely determine the condition of the intestinal wall, find any abnormalities and observe the surrounding areas.  The radiologist will evaluate the results that should be ready by the following day.  The patient will receive a CD of the images.