[Computed tomography and magnetic resonance tomography of rectal and sigmoid tumors].

CT and MR imaging are of minor importance for the preoperative diagnosis of rectosigmoid carcinoma. A synchronous colon tumor can be excluded with a barium enema, while an accurate diagnosis of liver metastases is possible using real-time ultrasonography. However, post-operative management requires the use of tomographic methods: MR imaging has proved to be more accurate than CT for differentiation between local recurrence and post-operative scars. Therefore MRI should be the method of choice after surgery for rectosigmoid carcinoma in all patients without postoperative baseline examinations.