Aim of the study is to compare the value of all described methods considering the detection rate of colorectal metastases, including the by now available intraoperative cm-ultrasound. From the comparison of all modern methods (64-line doublehelix CT, 3D virtual operation planning, 3 tesla Primovist-MRI, pre- and intraoperative contrast enhanced sonography) we aim to get a reliable recommendation for the preoperative necessary staging.