Virtual reality in MR-colonography

Early detection and subsequent removal of colorectal polyps have been shown to constitute an effective approach for decreasing the incidence of colorectal cancer. The lack of an ideal modality for colorectal polyp screening stimulated interest in the development of CT-colonography and MR-colonography. Both techniques allow the colon to be analyzed in a cross-sectional as well as a virtual endoscopic format. Causing no side-effects and not concerning for radiation exposure MR-colonography warrants further consideration. Additional to detecting polyps down to 6 mm in size the inner wall contour and the morphology of the colonic wall itself can be assessed. New developments like fecal tagging will increase patients acceptance comparing to other diagnostic techniques. In search of an ideal modality for polyp screening MR-colonography will become a potent option in the diagnostic arsenal. (orig.)