Abstract：To evaluate the value of 64-slice spiral CT in preoperative staging of colorectal carcinoma． Methods: Thirty-seven patients, who were strongly suspected to have colorectal carcinoma, underwent 64-slice CT before and after intravenous injection of iodinated contrast agent． CT virtual coloscopy(CTVC), MPR, SSD and Raysum images were obtained by using 4 different softwares in workstation. The results of 64-slice CT were compared with the findings of postoperative pathology． Results: 64-slice spiral CTVC could be helpful in showing the pathologic patterns of carcinoma, its accuracy rate was 91.90％. MPR was helpful for displaying directly the invasion of colonic wall and pericolic organ from colon carcinoma． The accuracy rate was 100％. Raysum was better to display the length of tumor, and its accuracy rate was 100％. MSCT pneumocolon examinations demonstrated 37 colorectal carcinoma. Sensitivity and positive accuracy value for T staging were 100％(37/37) and 89.2％(33/37), respectively； Sensitivity and positive accuracy value for lymph node involvement were 80％(24/30) and 70％(21/30), respectively. Conclusion: 64-slice spiral CT 3D-reconstructive images and virtual colonoscopy is a better method of depicting colorectal carcinoma, it could be more helpful to precise localizing and qualitative diagnosis. And it allows accurate staging for colorectal carcinoma, especially in detecting the invasion of adjacent tissues and distant metastasis．
2008, Vol. 19 
