Comparative study of CT and MRI in diagnosis and preoperative staging of rectal cancer

Objective The purpose of this study was to compare the accuracy of MRI and CT in the diagnosis and preoperative staging of rectal cancer. Methods 27 patients with rectal cancer proved surgically and histologically between January to December of 2007 were studied. Each of patients underwent MRI and CT examinations before surgical operation. MRI study included T1WI,T2WI and FSPGR pulse sequences. CT study included plain and contrast enhanced scanning. The size and signal intensity of tumor,surrounding infiltration,and lymph nodes around the rectum were observed. The imaging findings were compared with those from surgery and pathology. Results In the preoperative T staging,the accuracy of CT and MRI were 88.9% and 96.2%,respectively. The specificity of regional lymph node invasion with CT and MRI both were 97.6%; the sensitivity of regional lymph node invasion with CT and MRI were 24% and 36%,respectively. Conclusion MRI was superior to CT in the diagnosis and preoperative staging of rectal cancer.