[Preoperative imaging for colorectal cancer: surgeons' perspective].

Preoperative radiological diagnostics in patients with colorectal cancer has several objectives. The diagnostic localization of the colonic tumor is essential for planning the resection. The radiologically suspected infiltration of neighboring structures may lead to the decision for neoadjuvant treatment. In patients with rectal carcinomas, the T and N stages, the distance to the circumference resection margin (CRM), and the penetration of the tumor into the mesentery must be determined. This crucial to determine whether the patient should undergo neoadjuvant treatment. Prior to the planned relocation of an upstream stoma, radiological diagnostics may be added to clinical and endoscopic assessment but should not be routinely used.