Bhupinder Anand, MD
In this Article
What is virtual colonoscopy?
An alternative to colonoscopy is virtual colonoscopy. Virtual colonoscopy is a technique that uses CT scanning to obtain images of the colon that are similar to the views of the colon obtained by direct observation through colonoscopy. The images are constructed using the CT images so they do not represent true images. They are virtual images.
In preparation for virtual colonoscopy, the day before the examination, the colon is cleaned-out using laxatives. During the examination a tube is inserted into the anus and is used to inject air into the colon. The CT scans then are performed with the colon inflated, and the scans are analyzed and manipulated to form a virtual image of the colon. When properly performed, virtual colonoscopy can be effective. It can even find polyps "hiding" behind folds that occasionally are missed by colonoscopy.
Nevertheless, virtual colonoscopy has several limitations.
Because of these limitations, virtual colonoscopy has not replaced colonoscopy as the primary screening tool for individuals at increased risk for polyps or colon cancer. It is currently an option for individuals at normal risk for polyps and colon cancer who cannot or will not undergo colonoscopy.
Medically Reviewed by a Doctor on 7/15/2014