结肠CTVE成像的实验研究

Experimental study of CT virtual end oscopy of colon

目的探讨如何获取良好、准确和实用的结肠CTVE图像。方法利用猪结肠息肉模型,通过选择不同成像参数进行CTVE成像,分析各参数条件下CTVE图像的质量。结果共行10次螺旋CT容积扫描并进行CTVE成像及评分,10次图像总体统计学差别有显著性意义(F值为21.92,P<0.05)。其中:(1)改变层厚(Pitch=1、重叠重建率=50%):层厚为2、3、5、7、10mm时,各CTVE图像差别之间有显著性意义,其中层厚为2、3、5mm分别与层厚为7、10mm比较时,各CTVE图像差别有显著性意义;(2)改变Pitch(层厚2mm、重叠重建率=50%):Pitch分别为2.0、1.5、1.0时,各CTVE图像差别无显著性意义;(3)改变重叠重建率(层厚2mm、Pitch=1):重叠重建率分别为0%、25%、50%、75%时,各CTVE图像之间无显著性意义。结论层厚5mm,螺距2,重叠重建率50%即可获得满意的CTVE重建图像,亦能同时满足临床诊断的要求。

Objective To evaluate how to aquire excellent,accurate and practical images of CT v irtual en-doscopy(CTVE).Method A pig colon model was scanned by helic al computed tomography with a variety of section thicknesses(2,3,5,7,10mm),pitch(1.0,1.5,2.0)and overlap of reconstructed sectio ns(0%,25%,50%,75%).The CT volume data were transferred to wo rkstation and reconstructed,Ten groups of CTVE images were obtained and analyzed.Result There was a statistically significant difference in total among ten grou ps of CTVE images(F =21.92,P<0.05).Differences in image quality were s ignificant among section thickness of 2,3,5,7and 10mm.There was a statistically significant difference in image quality between the section thickness of 2,3,5mm and section thickness of 7and 10mm respectively.There was no significant di fference among the CTVE images with p itch of 1.0,1.5and 2.0or overlap of recon structed sections of 0%,25%,50%and75%.Conclusion The satisfactory CTVE images could be obtained with se ction thickness of 5mm,pitch of2and overlap of reconstructed sections o f50%,and met the clinical diagnosis.