A Comparative Study on Diagnostic Value of CT and MRI in Preoperative Local Staging for Rectal Cancer / 昆明医科大学学报

ABSTRACT

Objective The purpose of this article was to investigate the diagnostic value of CT and MRI in preoperative local staging for rectal cancer patients. Methods Forty rectal cancer patients were enrolled,and their preoperative CT and MRI staging and pathological staging in T and N were compared. Results The total diagnostic accordance rate of CT staging in T was 57.5%(31/40),among which the accordance rate of T1-2,T3 and T4 was 87.5%(35/40),83.25%(33/40) and 70%(28/40),respectively. The total diagnostic accordance rate of MRI staging in T was 77.5%(31/40), among which the accordance rate of T1-2, T3 and T4 was 92.5%(37/40), 77.5%(31/40) and 85%(34/40),respectively. The differences were tested by Chi-square test,and there were no significant differences between the two groups in T staging. The sensitivity of T staging by CT was 77.78%(7/9) for T1-2, 75% (12/16) for T3 and 93.33% (14/15) for T4. Compared with CT, the sensitivity of MRI was 66.67%(6/9) for T1-2, 81.25%(13/16) for T3 and 80%(12/15) for T4, and there were no significant differences between the two groups. The specificity of T staging by CT was 90.32% (28/31) for T1-2, 45.83%(11/24) for T3 and 96%(24/25) for T4. Compared with CT, the specificity of MRI was 100% (31/31) for T1-2, 75% (18/24) for T3 and 88%(22/25) for T4, and there was a significant difference in T3 specificity ( <0.05) . The total diagnostic accordance rate of CT staging in N was 82.5% (33/40),among which the rate of N- and N+was 82.5%(33/40) and 82.5%(33/40), respectively. The total diagnostic accordance rate of MRI staging in N was 62.5%(25/40),among which the rate of N- and N+was 62.5% (25/40) and 62.5%(25/40), respectively. There were significant differences between the two groups in pelvic N staging ( < 0.05) . The sensitivity of N staging by CT was 75.00%for N- (18/24) and 81.25%(13/16) for N+. Compared with CT,the sensitivity of MRI was 75.00%(18/24) for N- and 43.75%(7/16) for N+,and there were significant differences between the two groups ( <0.05) . The specificity of N staging by CT was 81.25% (13/16) for N- and 83.33%(20/24) for N+. Compared with CT, the specificity of MRI was 43.75% (7/16) for N- and 75.00%(18/24) for N+, and there were significant differences between the two groups ( <0.05) . Conclusion MRI has a high reliability in diagnosing rectal cancer with penetrating through the muscularis propria into the placenta percreta or not, but CT is superior in diagnosing the lymphonodus metastasis.