LOCAL STAGING OF ANAL AND DISTAL COLORECTAL TUMORS WITH THE MAGNETIC-RESONANCE ENDOSCOPE

Background: We prospectively assessed the feasibility and accuracy of endoscopic magnetic resonance (EMR) scanning in the local staging of a nal and colorectal cancer as compared to endosonography. Methods: Fift een patients with biopsy-proven anal (n = 2), rectal (n = 11), and dis tal colonic (n = 2) cancer underwent endosonography followed by EMR im aging. Scans were acquired using the magnetic resonance receiver coil incorporated into the tip of the non-ferromagnetic endoscope. Blinded to endosonography results, two radiologists interpreted the EMR images using the TNM system. Staging results were compared to endosonography in all patients and to histopathology in the 13 colorectal cases. Res ults: EMR imaging, well tolerated in all patients, correlated with end osonography in 10 of 15 and 12 of 15 cases for T- and N-staging, respe ctively. In the 13 colorectal patients with available histopathology, accuracy of EMR and of endosonography in T-staging was 77% and 85%, re spectively; N-staging accuracy was 62% for both. Conclusions: For anal and distal colorectal neoplasms, EMR imaging is feasible and provides local staging comparable to endosonography.