colonografie

Colonography, or colonography imaging, is a radiological examination of the large intestine designed to visualize the colon’s lining and detect abnormalities such as polyps, diverticula, inflammation, or tumors. The most widely used form is CT colonography, also called virtual colonoscopy, which relies on computed tomography to create two- and three-dimensional images after the colon is insufflated with air or carbon dioxide. Traditional radiographic colonography with fluoroscopic x‑ray and a contrast medium is less common today.

The procedure involves bowel preparation to clear the colon, followed by controlled insufflation of gas to distend the colon. A CT scan is then performed, sometimes with low-dose radiation, and specialized software generates interactive 3D views in addition to conventional two-dimensional images. The examination is generally completed without anesthesia and is faster than conventional colonoscopy.

Indications include colorectal cancer screening in adults, evaluation of symptoms such as unexplained bleeding or changes in bowel habit when traditional colonoscopy is not feasible, and assessment of diverticular disease or inflammatory bowel conditions. CT colonography has high sensitivity for larger polyps and cancers, but its ability to biopsy or remove lesions is limited, so any polyps detected typically require follow‑up colonoscopy for diagnosis and treatment.

Safety and limitations include exposure to ionizing radiation and a small risk of bowel perforation or discomfort from insufflation. Contraindications include acute abdomen or known intolerance to contrast. While not a replacement for therapeutic colonoscopy, colonography provides a noninvasive option for colorectal visualization when conventional colonoscopy is unsuitable.