[State of the art of MR colonoscopy]

MR colonoscopy is suitable for colorectal cancer screening. This imaging modality is non-invasive, has no harmful side effects and provides a high diagnostic accuracy. MR colonoscopy has been found to be highly sensitive and specific in detecting colorectal lesions > 10 mm in size. Since colonic polyps are difficult to differentiate from residual stool, colonic cleansing has been unavoidable but reduces patient acceptance. Cleansing of the bowel can be avoided if the signal of stool is rendered different from its surrounding. This can be achieved by adding an agent to the food that tags the feces (fecal tagging). This article describes current techniques of MR colonoscopy as well as first results with fecal tagging.