RECTAL TUMORS - MR-IMAGING WITH ENDORECTAL AND OR PHASED-ARRAY COILS,AND HISTOPATHOLOGICAL STAGING ON GIANT SECTIONS - A COMPARATIVE-STUDY/

Objective: To investigate the accuracy of MR imaging in the preoperati ve staging of patients with clinically resectable rectal tumours. Mate rial and Methods: Forty-eight consecutive patients with rectal tumours were examined, 29 with a pelvic phased-array coil and 19 with a multi -coil arrangement including a pelvic phased-array coil and an endorect al coil. MR images and histopathological specimens and sections were r eviewed independently and tumours were staged according to the TNM cla ssification. Results: A more complete visualisation of the various lay ers of the rectal wall was achieved on the endorectal MR images than o n the pelvic phased-array images. The sensitivity of MR in correctly s taging T3 tumours compared with histopathology was 81% with a specific ity of 82%. Penetration of the rectal wall was predicted with a sensit ivity of 82% and a specificity of 87%. Sensitivity and specificity in predicting lymph node metastases was 83% and 74% respectively. Conclus ion: MR imaging with both pelvic phased-array and endorectal coils all owed the preoperative staging of rectal tumours with a high degree of accuracy.