能谱CT血管造影最佳单能量结合自适应统计迭代重建优化显示胸背动脉

Optimizing visualization of thoracodorsal artery using energy spectrum CT angiography optimal single energy imaging combined with adaptive statistical iterative reconstruction V

目的观察能谱CT血管造影(CTA)最佳单能量结合自适应统计迭代重建(ASIR-V)优化显示胸背动脉(TDA)的价值。方法前瞻性对60例患者行能谱CTA观察TDA,重建120 kVp-like图像结合后置40%ASIR-V(A组),以及45~70 keV(间隔5 keV)单能量图像结合后置40%、60%及80%ASIR-V图像(B组,共18种);比较各图像主观评分及客观评价结果。结果ASIR-V权重相同时,不同能级下轴位及三维图像的主观评分差异均有统计学意义(P均<0.001);随能级升高,轴位图像主观评分呈先升后降趋势,以50 keV图像主观评分最高(P均<0.001)。能级相同时,随ASIR-V权重升高,轴位图像总体及三维图像所示TDA主干主观评分及腋动脉对比度噪声比均升高(P均<0.01)。结论行CTA时,以50 keV单能量图像联合后置80%ASIR-V重建有利于平衡图像对比度与噪声、更好地显示TDA及其分支。

Objective To observe the value of energy spectrum CT angiography(CTA)optimal single energy imaging combined with adaptive statistical iterative reconstruction V(ASIR-V)for optimizing visualization of thoracodorsal artery(TDA).Methods Energy spectrum CTA was prospectively performed in 60 patients to observe TDA.The images were reconstructed as 120 kVp-like combined with 40%post-set ASIR-V(group A),as well as totally 18 kinds of single energy images ranging from 45 to 70 keV(with interval of 5 keV)combined with 40%,60%and 80%post-set ASIR-V(group B),and the subjective and objective evaluation results of the images were compared between and within groups.Results Under the same post-set ASIR-V weight,significant differences of subjective scores of axial and 3D images were found among different keV levels(all P<0.001).With the increase of keV level,subjective scores of axial images increased first and then decreased,among which subjective score of 50 keV was the highest(all P<0.001).Under the same keV levels,with the increase of ASIR-V weight,the subjective scores of overall axial images and 3D images for displaying the main trunk of TDA,as well as contrast-to-noise ratio of axillary artery increased(all P<0.01).Conclusion Performing CTA using 50 keV single energy imaging combined with 80%ASIR-V reconstruction could balance image contrast and noise better,hence improving visualization of TDA and its branches.