 The purpose of this study is to determine whether a colonic tumor can be classified as malignant or benign with magnetic resonance MR colonography. Patients with a verified colon carcinoma or benign tumor based on diverticulitis are offered a MR colonography with intravenous I.V. contrast. The tumor is classified as malignant or benign by assessing the dynamic contrast uptake and morphology. The Investigator is blinded from the verified diagnosis and the MR classification is compared to the histological diagnosis. 