中文摘要：

目的探讨临床应用二氧化碳CO2作为造影介质进行小肠CT仿真内镜检查（CTVE）的可行性。方法取新鲜猪空肠标本30段，于每段空肠标本内壁模拟制作同等直径、高度分别为5、10和15 mm大小的模拟占位各3枚。随机把30段空肠模型分为CO2组、空气组和充水组3组，每组各10段，模拟占位各30枚，行多层螺旋CT扫描，利用工作站进行成像，比较应用不同造影介质的充盈方法对猪空肠占位性病变的检出情况、占位性病变的显示效果评分。结果CO2组、空气组和充水组CTVE对猪空肠占位性病变的检出率分别为90.00%、86.67%和76.67%，CO2组与空气组效果相当（P 〉0.05），与充水组比较差异有统计学意义（P 〈0.01）。在模拟占位高度为5和10 mm时，CO2组和空气组评分均优于充水组（P 〈0.01）；模拟占位高度为15 mm时，CO2组、空气组评分与充水组评分比较均无明显差异（P 〉0.05）。结论离体猪空肠实验提示CO2可替代空气作为小肠CTVE的新型造影介质，临床实际应用有待进一步大规模临床随机对照试验证实。

英文摘要：

ObjectiveTo investigate the feasibility of carbon dioxide as a contrast medium for CT virtual endoscopy （CTVE）. MethodsTaken fresh pig specimens of 30 sections and making simulation for occupying lesion on the inner wall, in the same diameter and height were 5 mm, 10 mm, 15 mm. 30 sections were randomly divided into 3 groups： the carbon dioxide group, the air group and the water filling group, scanning and imaging by multi-slice spiral CT. Compared the effect of filling method with different contrast medium on the occupying lesion. Results The detection rate of space occupying lesions in pigs were 90.00 %, 86.67 %, 76.67 %, in the carbon dioxide, the air and the water filling group, There was significant difference between the carbon dioxide group and the water filling group （P 〈0.01）; and no significant difference for the air group （P 〉0.05）. When the 5 mm and 10 mm were simulated, the scores of the carbon dioxide and the air group were better than those of water filling group （P 〈0.01）; the scores of the carbon dioxide and the air group were no significant difference than those of water filling group （P 〉0.05） when 15 mm. ConclusionsThe experiment suggested that carbon dioxide could replace the air as a new type of contrast medium, but should be confirmed by further large-scale clinical randomized controlled trials.