A
virtual colonoscopy or a CT colonography is where a CT imaging device is used to look at the interior of the colon that has traditionally only been examined when an endoscope has been inserted into the rectum.
The most common reason for having a virtual colonoscopy is for the screening of polyps and other lesions that may be present in the large intestine. Polyps are benign growths that form on the inner lining of the intestine. Polyps can become problematic as well as turn into cancer.
The advantage of having a virtual colonoscopy is the early detection of these growths that enables your physician to remove them before cancer has a chance to develop. It is recommended that anyone over the age of 50 be screened for polyps every 7-10 years. If you have high risk factors, you should be screened every 5 years.
High Risk Factors Include:• History of polyps
• Family history of colon cancer
• Presence of blood in the stool
The ProcedureYou will be positioned on the CT examination table, in most case scenarios, lying flat on your back, your side or on your stomach. If you have are experiencing a difficult time holding the correct position during the exam, straps and pillows may be needed to assist you.
A very small, flexible tube will be inserted approximately two inches into your rectum to allow air to be gently pumped into the colon using a hand-held squeeze bulb. In some cases an electronic pump is used to deliver carbon dioxide gas into the colon. No matter which device is being used, you will be able to control the amount of air or gas passing into the colon. The whole reason behind the gas being pumped in is so that the colon may be distended in order to eliminate any folds or wrinkles that might obscure polyps from your doctor's view.
Next, the table will move slowly through the machine as the actual CT Imaging is completed. You will be asked to hold your breath for about 15 seconds before turning over and lying on their back for a second pass is made through the scanner. You will need to wait until the technologist determines that the images are of high enough quality for the radiologist to read. The procedure usually lasts only 15 minutes.
