Comparison of magnetic resonance imaging and computed tomography in the preoperative staging of rectal cancer
C. Guinet, J. N. Buy, M. A. Ghossain, A. Sezeur, A. Mallet, J. M. Bigot, D. Vadrot and J. Ecoiffier
Department of Radiology, Hotel-Dieu de Paris, France.
Nineteen patients with middle and lower rectal carcinomas were operated on,
with abdominoperineal resection in 10 patients, lower anterior resection
with coloanal anastomosis in 6 patients, and colorectal anastomosis in 3
patients. The distance of the lower margin of the tumor to insertion of the
levator ani on the rectal wall was correctly evaluated by computed
tomography in 12 (63%) of 19 patients and by magnetic resonance imaging in
13 (68%) of 19 patients, while digital examination correctly assessed the
distance in 15 (79%) of 19 patients. Computed tomography and magnetic
resonance imaging were unable to assess extension through the rectal wall.
No significant difference was observed between computed tomography and
magnetic resonance imaging in assessing extension to the perivesical fat,
adjacent organs, pelvic side wall, or lymph nodes. According to the TNM
classification, magnetic resonance imaging correctly staged 74% (14/19) of
carcinomas, while computed tomography correctly staged 68% (13/19).
