The value of MR imaging in the diagnosis of colonic carcinoma / 中华放射学杂志

ABSTRACT

Objective To investigate the MR imaging findings of colonic carcinoma and the diagnostic value of MRI. Methods Multi-planar and multi-sequence MRI scanning, before and after contrast enhancement, were performed in 40 patients with colonic cancer. The patients were fasted for 12 hours, prepared with clean clysis or senna at night before study, given 10 mg of anisodamine 10 minutes before study, and then infused with 800～1 000 ml physiological saline immediately before study by anus. Dukes staging and resectability evaluation were made in 32 patients before surgery and meanwhile the results were compared with pathology. Results Colonic anatomy and surrounding organs were clearly demonstrated on MRI in 40 patients with colonic cancer, particularly in recta and sigmoid flexure. The tumours showed iso-intensity on T 1WI, iso-intensity or slight high-intensity signal on T 2WI, and high-intensity signal on SPIR. Remarkable enhancement was seen in 35/40 (87.5%). Invasion of surrounding organs occurred in 8/40(20.0%)and MRI revealed 6; Meanwhile, MRI revealed lymph node metastasis in 8 out of 12 cases. 32 patients were regarded as resectable before surgery, and 8 patients as unresectable. Four patients were overestimated, the accuracy of preoperative evaluation for the resectability was 87.5%, and the detecting rate of colonic cancer was 100.0%. Conclusion MRI can clearly show the colonic wall thickness, anatomic structure and surrounding anatomy. For the diagnosis of colonic cancer, MRI can not only demonstrate all its morphologic features, such as mass, thickened wall, and invasion of adjacent organs, but also swollen lymph node and metastasis in abdominal cavity. MRI is very helpful in the diagnosis, staging, and respectability evaluation of colonic cancer.