PREOPERATIVE STAGING OF RECTAL-CARCINOMA BY MAGNETIC-RESONANCE-IMAGING WITH A PELVIC PHASED-ARRAY COIL

Background The use of surface coils for magnetic resonance imaging (MR I) allows enhanced image definition and so potentially more accurate s taging of colorectal cancer. Endorectal coil imaging is invasive, oper ator dependent and impossible in a high proportion of patients due to rectal stricture. The phased-array pelvic coil, however, is non-invasi ve and applicable to all rectal tumours.Methods A pelvic phased-array coil was used for preoperative MRI staging of 38 primary rectal carcin omas, Results were expressed according to the Dukes and tumour nodes m etastasis (TNM) classifications. After resection of the tumour, the st age predicted on MRI was compared with the pathological classification . Results The overall accuracy of preoperative staging with the pelvic phased-array coil was 55 per cent for both Dukes class and T stage. A ssessment of nodal involvement gave an overall accuracy for MRI of 76 per cent with a sensitivity of 57 per cent and specificity of 88 per c ent. Conclusion Use of a pelvic phased-array coil did not improve the staging accuracy of MRI to a clinically useful level.