Colorectal cancer: cross-sectional imaging for staging of primary tumor and detection of local recurrence.

This review describes the use of cross-sectional imaging in the staging of colorectal carcinoma and detection of local recurrence. The contributions of CT, MR imaging, and sonography are discussed and illustrated. Colorectal carcinoma is the second most common tumor in the United States and the most common cancer in the gastrointestinal tract. The prognosis for patients with this neoplasm is closely related to the extent of tumor at the time of diagnosis. Accurate noninvasive preoperative assessment of tumor stage by one or a combination of radiologic techniques would enable appropriate treatment to be planned in each case. Also, determination of possible tumor recurrence would permit effective monitoring of success of therapy and surgical intervention for recurrent disease before widespread metastasis occurs.