多层螺旋CT腹腔动脉成像在不同重叠率与成像方法的相关研究

目的:通过比较3种不同的重叠率所获得的腹腔动脉及其分支图像质量,以获得多层螺旋CT(MSCT)血管成像(MSCTA)理想的重建参数。方法:随机选择45例临床推荐行腹部增强扫描的患者纳入研究,选择3.0 mm×2.5 mm的扫描参数,对横断面扫描图像的原始数据分别用重叠率0％,50％和75％进行层厚3.0 mm轴面重建。采用最大密度投影(MIP)和容积重建(VR)两种后处理成像方法。根据腹腔动脉及分支血管边缘的清晰度、腹腔动脉的分支级别显示情况进行综合评分,由2位有经验的放射科医师用双盲法评分,所有统计工作应用SPSS软件完成。结果:3种不同重叠率对腹腔动脉血管成像的总体质量以75%与50％重叠率图像质量最佳,两者差异无显著性(P>0.05),75％、50％重叠率图像质量高于重叠率0％(P<0.05)。结论:多层螺旋CT腹腔动脉血管成像选择3.0 mm层厚、50％重叠率能很好显示腹腔动脉及分支,VR比MIP重建的血管图像更优。

Multislice Spiral CT Celiac Arteriography:a Comparative Study of Image Quality with Different Section Overlap and Reconstruction

To obtain the optimal reconstruction parameters of multislice spiral CT angiography (MSCTA) for celiac artery and its branches by comparing the quality of the images obtained with three section overlaps. Methods: Forty-five patients recommended to abdominal reinforcement scan were randomly selected in this investigation. Images were obtained with 3. 0 mm X 2. 5 mm scan project, and the raw data was reconstructed with 3. 0 mm thick section and using 0%, 50% and 75% section overlap. Respectively, maximum intensity projection(MIP) and volume rendering(VR) were used for image reconstruction. Based on the marginal sharpness and the branch levels of the displayed vessels, a general evaluation of the image quality of the celiac artery and its branches was done by two experienced radiologists with double-blind method. A comparison of the image quality among three groups was made with statistic software of SPSS. Results: By comparing the quality of the images obtained with 0%, 50% , 75% section overlap, images using 75% and 50% section overlap showed the same best quality ( P> 0. 05), and better quality than that using 0% section overlap( P < 0. 05) . Conclusion: For better displaying celiac artery and its branches with multislice spiral CT angiography, parameters of 3. 0 mm thick reconstruction with 50% section overlap are recommended and reconstruction images of VR are better than that of MIP.