Clinical Application Of 64-slice Spiral CT In Colorectal Diseases

Objective: To determine the applied value of multislice spiral CT(MSCT) of in the diagnosis of colonic diseases. Methods: The volume scan of 64-slice spiral CT pneumocolon was performed in whole colorectum of 73 cases,then data was transmitted to the work station,CT virtual colonography(CTVC),multiplanar reconstruction (MPR),surface shaded display(SSD),Raysum were performed respectively.Combined with the original axial section ,The results were compared withthe findings of colonoscopy or postoperative pathology. CTVE.MPR.SSD,and Raysum images of thirty-seven patients,who were strongly suspected to have colonic carcinoma, were performed respective1y.The results were compared and anayzed according to the image processing.They were staged preoperatively according to TNM standard.All cases were proved by surgical or colono- scopic histology.Results : Sensitivity,specificity,false positive proportion and false negative proportion for detection of colorectal carcinoma were 91.89%(34/37),82.86%(13/14),7.14% and 8.11%,respectively.MSCTVC has a high sensitivity (89%)for detection of=1cm colorectal polyps but not for <1 cm colorectal polyps. MSCTVC could be helpful in showing the pathologic patterns of carcinoma.MPR was helpful for displaying directly the invasion of colonic wall and pericolic organ from colon carcinoma.The accuracy of detecting the invasion of pericolic tissue or organ was 100%. Raysum was better to display the length of tumor,and its accuracy rate was 100%.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 plan an unique role in the diagnosis of Colorectal Carcinoma,extensive clinical application is recommended.