双瞬切能谱扫描模式下不同权重迭代算法对腹部能谱参数的影响

Effects of different weighted iterative algorithms on abdominal energy spectrum parameters in dual-shot spectral CT scanning mode

目的双瞬切能谱扫描模式下的不同权重迭代算法对腹部能谱图像单能量、有效原子序数、基物质对等参数的影响。方法前瞻性收集20例行腹部CT扫描的患者,采用电流和电压同时双瞬切新型能谱扫描模式。对静脉期图像应用能谱分析软件GSI Viewer在同一层面肝脏等地方勾画感兴趣区,获取每个ROI中有效原子序数、基物质对图像及74 keV单能量图像的CT值和噪声,计算信噪比。采用单因素方差分析比较不同权重ASiR-V重建的有效原子序数、基物质对图像及74 keV单能量图像SD、SNR组间比较差异。结果20例患者随着ASiR-V权重增加,有效原子序数、基物质对值及74 keV单能量图像CT值比较差异无统计学意义(P>0.05),图像的SD值逐渐减小,质量改善。不同权重的ASiR-V对有效原子序数、基物质对值及74 keV单能量有类似的影响。结论基于新的双瞬切能谱扫描模式下的不同权重迭代算法,与74 keV单能量一样,能够优化有效原子序数的图像质量。

Objective To investigate the effects of different weighted iterative algorithms on abdominal spectral images in dual-energy spectral CT scanning mode in terms of single energy,effective atomic number and basis material pairs.Methods Prospective collection of 20 patients undergoing abdominal CT scans using a novel dual-energy spectral scanning mode with simultaneous current and voltage.The GSI Viewer spectral analysis software was applied to delineate regions of interest in the liver and other areas on portal phase images at the same level,obtaining CT values and noise for effective atomic number,basis material pairs images,and 74keV monoenergetic images in each ROI,and calculating signal-to-noise ratio.Results In 20 patients,as the ASiR-V weight increased,there were no significant statistical differences in the effective atomic number,basis material pairs values,and 74keV monoenergetic image CT values(P>0.05);the standard deviation values of the images gradually decreased,indicating an improvement in quality.Different weights of ASiR-V had similar effects on the effective atomic number,basis material pairs values,and 74keV monoenergetic images.Conclusion Based on the new dual-energy spectral scanning mode,different weight iterative algorithms can optimize the image quality of effective atomic number similar to that of 74keV single-energy images.