http://www.appliedradiology.com RSS Feed on Applied Radiologyhttp://www.appliedradiology.com//Issues/2003/06/Supplements/Virtual-imaging-of-the-colon-by-CT,-including-the-use-of-intravenous-contrast-material.aspxThe effectiveness of screening and polypectomy in reducing colon cancer incidence and mortality is well known. Virtual colonoscopy, an advanced application of computed tomography (CT), has demonstrated great potential for revolutionizing colon cancer screening. Multislice helical CT technology, three-dimensional (3D) reconstruction techniques, and lower radiation dose protocols have significantly improved the sensitivity of virtual colonoscopy. In addition to screening, several other important applications of CT colonography are under investigation. One important new application is the evaluation of patients in whom tissue diagnosis has already been obtained. Appropriate staging of such patients is essential for avoiding unnecessary morbidity and maximizing therapeutic benefit. Virtual colonoscopy plays an important role in preoperative evaluation by accomplishing both surveillance for metastases and evaluation of mucosal disease in a single procedure while minimizing patient discomfort. CT colonography is helpful in postoperative surveillance as well. Intravenous contrast plays an important role in these pre- and postsurgical patients by improving both visualization and characterization of lesions and overcoming many of the previous limitations of virtual colonoscopy.Wednesday, 11 Jun 2003 15:24:25 GMT