["Virtual colonoscopy": back to the future?].

"Virtual colonoscopy" is a new method of producing an endoscopic view of the colon without endoscopy. The images are derived from the data of conventional abdominal computer-tomography or magnetic resonance tomography, using modern computer programmes. The method makes it possible to detect colonic polyps or carcinomas with a sensitivity and specificity of 80%. The most interesting application of "virtual colonoscopy" may be as a screening method for colorectal polyps in preventing the development of colorectal cancer. This may improve patient acceptance for colorectal cancer screening programmes.