Abstract

PURPOSE
We studied to determine the usefulness of magnetic resonance imaging (MRI) in the preoperative T-staging of colorectal cancer.
MATERIALS AND METHODS
Twenty patients with colon cancer and S patients with rectosigmoid neoplasm, who were diagnosed between October 1997 and June 1998 by barium enema, colono-scopic biopsy were evaluated. Patients consisted of 16 men and 12 women, with ages ranging from 46 to 68 years (mean 61 years). Preoperative staging was done with MRI. We used 2D-FLASH (Fast Low-Angle Shot), FISP (Fast-Imaging Shot-angle Precession), and Turbo-SE (Spin-Echo) sequences. Acquisition time of these MR techniques was 13~15 sec. 2D-FLASH MRI after intravenous injection of 0.1 mmol/kg Gd-DTPA were obtained for the dynamic and delayed enhanced MR images. Preoperative stages of MRI were decided with a consensus by two radiologists. Pathologic stages were done by TNM classification.
RESULTS
T-stages determined by enhanced 2D-FLASH MR images of colorectal cancer were correlated with histopathologic findings in 2 of 3 pT2 (pathologic T2) tumor (67%), 17 of 21 pT3 (81%), and 4 of 4 pT4 tumors (100%). T-stages determined by FISP were correlated with histopathologic findings in 2 of 3 pT2 tumor (67%), 16 of 21 pT3 (76%), and 3 of 4 pT4 tumors (75%), and T-stages by Turbo-SE were correlated in 2 of 3 pT2 tumor (67%), 18 of 21 pT3 (86%), and 3 of 4 pT4 tumors (75%). MRI correctly diagnosed tumor deposits of involved lymph nodes in 16 patients, overall accuracy was 57% (16/28%). Signal intensity between the cancerous and normal wall was not significantly different on MRI using FISP (P>0.05). But, that was significantly different on the MRI using Turbo-SE (p<0.05), CONCLUSION: Fast MR sequences has a role for the preoperative T-staging of colorectal neoplasm.

• Keywords: Colorectal neoplasm;Stage;Magnetic resonace imaging