Coloscanner is a new radiologic tool to determine if abnormalities of colon and especially neoplasms are present. Considering its sensitivity and its tolerance, it could become in the next future a useful tool for screening of certain at risk populations. Positron emission tomography (PET) using fluorodeoxyglucose (18F) is the first functional imaging modality already available in oncology. In colorectal neoplasm, it is now considered as essential for the diagnosis of unexplained raise of CEA levels, differential diagnosis between benign and malignant disease (especially for suspected local recurrence of rectal cancer), or preoperative staging in case of complex surgical strategies. Its role in early determination of therapeutic response should be evaluated.