Virtual Colonoscopy
Virtual Colonoscopy is a medical procedure wherein the colon and the rectum are viewed through a computer screen. It is done to:
- to detect early signs of cancer
- to determine abnormal growths (such as pre-cancer growths) known as polyps
Early detection of pre-cancerous and cancerous growths in the colon or rectum is vital since this will allow the doctor to immediately remove these abnormal growths and stop them from progressing.
What is the Procedure for Virtual Colonoscopy
The virtual colonoscopy procedure can be done using a Computer Tomography machine otherwise known as CT scan or using a Magnetic Resonance Imaging equipment also known as MRI.
More often however, virtual colonoscopy is done through a CT scan also called CT Colonography. The insides of the colon and rectum are photographed via x-ray and the images are then projected on the attached computer’s screen.
This gives the radiologist 3-dimensional images of the internal parts of the large intestine where the above mentioned abnormal growths called polyps could be present.
On the other hand, if virtual colonoscopy is done using MRI, instead of using x-ray equipment, images are photographed through magnets that emit radio frequencies. The images are then transported to the attached computer screen.
During both procedures, patients will be asked to lie on a table, flat on their backs. The table will then be moved through the CT scanner or MRI machine to take images of the insides of the colon and rectum.
Preparation for Virtual Colonoscopy
Similar to the preparations for conventional colonoscopy, a patient will be required to cleanse the large intestine through a liquid diet that could be prescribed for 1-3 days.
All solid foods will have to be eliminated first and clear liquids will have to be taken. Broth, water, plain coffee or tea and sports beverages are acceptable during this time.
On the eve of the virtual colonoscopy, patients will be given a laxative to eliminate stools.
The Procedure
On the day of the procedure, patients will be asked to drink what is called contrast media, for those taking the CT Colonography. This drink makes the large intestine clearly visible during the scan.
During the CT Colonography procedure, a slim tube will be inserted in the patient’s anus region where carbon dioxide will be released into the large intestine to give a clearer view.
For an MRI procedure, contrast media will be administered through the rectum. Both procedures will take approximately ten minutes only and the patient will not be sedated unlike in a conventional colonoscopy procedure.
Patients can immediately go home after the test and go about their usual, daily routine.