Cancer of the colon and/or rectum (colorectal cancer) is the third most common cancer diagnosed in America. Before a true cancer develops, there are usually precancerous changes in the lining of the colon or rectum. The most common is the growth of polyps. The goal of screening for colorectal cancer is to find polyps and cancers before they cause symptoms because early detection offers the best opportunity for successful treatment.
The number one exam used to detect colorectal cancer is an optical colonoscopy. This test is not performed at EPIC but in a doctor’s office or hospital. A long scope with a tiny camera attached is inserted into the rectum and slowly moved through the length of the colon to look for precancerous changes and polyps in the lining of the colon. If polyps are found during a colonoscopy, the doctor may remove them on the spot.
Colonoscopy is an invasive, expensive and uncomfortable procedure that takes up to an hour to complete. Sedation is generally required and an aggressive preparation of cleansing the bowel with laxatives must be followed. Patients are often reluctant to schedule the exam for these reasons.
CT Colonoscopy at EPIC Imaging (also called Virtual Colonoscopy) offers an alternative for those patients. This exam is performed with an ultra fast CT scanner equipped with sophisticated virtual reality software. A small, flexible rubber tube is inserted into the rectum so that puffs of air can be introduced to inflate the cleansed colon. The only discomfort is a mild sensation like a gas pain when the air is introduced.
Images are rapidly acquired by the CT scanner and in 10 to 20 minutes the exam is completed. Because no sedation is necessary, normal activity can be resumed immediately
The disadvantage of CT Colonoscopy is that polyps cannot be removed on the spot. If polyps are found, you may need to undergo the traditional colonoscopy to remove them. However, the exact location of the polyps will have already been identified, lessening the time involved.
CT Colonoscopy is also frequently used when patients are unable to complete a traditional colonoscopy. This happens when a physician is not able to manipulate the scope through the entire length of the colon. This may be due to a variety of factors like diverticular disease, orthopedic deformities or discomfort. When this happens, the exam is termed “incomplete.”
Who should consider CT Colonoscopy: