【摘要】 目的　探讨多层面螺旋CT血管成像 (MSCTA)中扫描参数和重建方法的影响。资料与方法　 6 0例共 12 0次MSCT扫描 ,MarconiMx80 0 0型 4层CT扫描仪 ,分别将准直层厚 5 .0mm、2 .5mm、1.0mm与Pitch 0 .875、1.2 5、1.75相匹配 ,各组数据分别以 0 %、5 0 %、70 %重叠重建率 ,对容积再现 (VR)重建血管图像的图像质量和血管分支级数显示评分 ,不同层厚、重叠重建率和Pitch分组比较 ,将准直层厚 2 .5mm、1.0mm组 ,重叠 5 0 %重建 6 8次血管成像行最大密度投影 (MIP)重建 ,与对应VR图像行配对t检验。结果　准直层厚 1.0mm组 0 %和 5 0 %重叠重建及准直层厚 2 .5mm组重叠重建率 5 0 %、70 %图像得分无显著性差异 ,但与准直层厚 2 .5mm组重叠重建率 0 %及准直层厚5 .0mm组图像得分有显著性差异 ;准直层厚 2 .5mm时 3种Pitch图像得分无显著性差异 ;准直层厚 2 .5mm和 1.0mm时VR重建和MIP重建的得分无显著性差异。结论　MSCTA时选择适当的扫描重建参数 ,可以显示较多血管分支级数 ,获得较好的图像质量 ,其优化的条件为 :准直层厚 2 .5mm ,Pitch 1.75 ,5 0 %重叠重建 ,两种重建方法VR和MIP在显示血管方面无明显差别。更多还原

【Abstract】 Objective To investigate the influence of scanning and reconstruction parameters on image quality in multi-slice CT angiography (MSCTA).Materials and Methods Separately using collimation width of 4×1 mm, 4×2.5 mm and 4×5 mm, and pitch of 0.875, 1.25 and 1.75, 108 MSCTA exams were performed in 60 patients on a multi-slice CT unit (Marconi Mx8000 Quad). The initial images were respectively reconstructed with 0%, 50% and 70% overlapping rate. The volume rendering (VR) image quality, including the identifiable vessel branches, was scored and analyzed. VR and maximum intensity projection (MIP) images using collimation width of 4×1 mm and 4×2.5 mm were compared.Results No significant difference in scores existed between the group using 4×1 mm collimation width and 0% or 50% overlapping and the group using 4×2.5 mm collimation width and 50% or 70% overlapping. Significant difference in scores existed between the above groups and the groups using 4×2.5 mm (with 0% overlapping rate) or 4×5 mm. No significant difference in scores existed between different pitch groups and between VR and MIP images.Conclusion When proper scanning and reconstructed parameters are used, MSCTA can provide high-quality images with more identifiable vessel branches. The optimized parameters obtained from this study include collimation width 4×2.5 mm, pitch 1.75 and 50% overlapping reconstruction. Both VR and MIP can well display the vessels.更多还原