1. What is a virtual colonoscopy?
A virtual colonoscopy, also known as CT colonography, is a noninvasive imaging test designed to detect polyps and cancers within the colon and rectum. Unlike traditional colonoscopy, it does not involve inserting a scope inside the colon. Instead, it uses computed tomography (CT) scanning combined with computer software to create detailed two-dimensional and three-dimensional images of the entire colon from outside the body.
This procedure provides a virtual “fly-through” view of the colon, allowing healthcare providers to identify abnormal growths that could potentially develop into colorectal cancer. It typically takes about 15 minutes and does not require sedation, making it a less invasive screening option.
2. How does it work?
During a virtual colonoscopy, a CT scanner takes multiple X-ray images of your abdomen and pelvis. Before the scan, a small tube is inserted into the rectum to gently inflate the colon with air or carbon dioxide. This inflation expands the colon walls so the scanner can capture clear, detailed images.
A computer then processes these images to reconstruct a 3D model of your colon. A radiologist reviews this model to identify any polyps or suspicious areas. If polyps are detected, a traditional colonoscopy will be necessary to physically remove them and perform biopsies if needed.
