[Magnetic resonance with endorectal coil in the locoregional staging of rectal carcinoma].

The accurate locoregional staging of rectal cancer is important in choosing and planning therapy. The diagnostic contribution of endorectal ultrasonography and of Computed Tomography is well known because both methods have been widely used in the last ten years. More recently, Magnetic Resonance Imaging (MRI) has been introduced in the preoperative staging of rectal cancer: most interestingly, in the last three years endorectal surface coils have become available as a clinical device. February through November, 1994, twenty patients affected with rectal carcinoma were examined with endorectal MRI. In order to assess their accuracy, MR staging results were compared with pathologic findings. MRI was performed with an 0.5 T system equipped with an endorectal surface coil. In all cases T2-weighted turbo spin-echo sequences were performed on axial and sagittal or coronal planes. Rectal wall layers were reliably demonstrated in all patients. The comparison with pathologic findings showed 78.9% MR accuracy in assessing tumor infiltration depth. In addition, the study of perirectal lymph nodes showed 83.2% MR sensitivity and 53.8% MR specificity. The high resolution images obtained using endorectal surface coils and the well-known panoramic capabilities of this method reveal MR potentials in rectal carcinoma staging.