What is a Virtual Colonoscopy

What is a Virtual Colonoscopy?

What is a Virtual Colonoscopy?

Virtual colonography, also known as computed tomography (CT) colonography or CT colonoscopy, is a diagnostic imaging test that, similar to traditional x-rays, generates multiple images of the body’s interior. These cross-sectional images can be reformatted into various planes and can even produce three-dimensional reconstructions. They are typically viewed on a computer monitor, printed on film, or stored on a CD or DVD.

CT scans provide detailed images of internal organs, bones, soft tissues, and blood vessels, offering greater clarity compared to traditional x-rays, especially for soft tissues and blood vessels.

CT colonography specifically utilizes low-dose radiation CT scanning to visualize the interior of the colon, also known as the large intestine. This allows for a non-invasive alternative to traditional colonoscopy, where an endoscope is inserted into the rectum and passed through the entire colon.

Procedure of CT Colonoscopy

The technologist initiates the CT examination by positioning you on the examination table, typically lying flat on your back, although occasionally on your side or stomach. Straps and pillows may be utilized to assist in maintaining the correct position and ensuring stillness throughout the procedure. Depending on the area of the body being scanned, you may be instructed to raise your arms over your head.

To facilitate the examination of the colon, a very small, flexible tube is inserted approximately two inches into the rectum. This allows for the gentle introduction of air into the colon using a hand-held squeeze bulb or, in some cases, an electronic pump delivering carbon dioxide gas. Additionally, a small balloon may be inflated on the rectal tube to aid in maintaining its correct position. The purpose of the introduced gas is to distend the colon, minimizing any folds or wrinkles that could obscure polyps from the physician’s view.

Subsequently, the examination table moves through the scanner. Patients are requested to briefly hold their breath for approximately 15 seconds or less before repositioning and lying on their back or side for a second pass through the scanner. Depending on the facility, the sequence of positions may be reversed: starting facing upward and then transitioning to facing downward. Upon completion of the scan, the rectal tube is removed.

Typically, the entire procedure is concluded within 15 minutes.