宝石CT能谱成像在去除金属植入物伪影方面的初步评价

目的评估宝石CT能谱成像在去除金属植入物伪影方面的价值。方法对18例带有金属植入物的患者行宝石CT能谱扫描，得到140kVp混合能量和65keV、100keV单能量图像（加去伪影技术），根据每例患者不同解剖部位及金属植入物形态，选择代表性层面40幅，分别测量并计算三组图像的伪影指数，由2位高年资放射科医师进行肉眼观察评估伪影等级。采用方差分析及卡方检验对伪影指数及伪影分级进行统计学分析。结果方差分析结果显示100keV单能量组金属伪影指数较混合能量组显著减低（P〈0．05），卡方检验结果显示100keV单能量组与QC以及65keV单能量组之间差异有统计学意义（P=0．000）。结论宝石CT能谱成像可以明显减少金属伪影，显著提高金属植入物周围结构的显示能力。

Objective To evaluate the value of gemstone CT spectral imaging in reducing the artifact of metal implants. Methods 18 patients with metal implants underwent gemstone CT spectral scan and 140kVp mixture energy, 65keV as well as 100keV mono - energy images （ Multi - artifact Reduction System was used） were obtained. According to different anatomical sites and the shape of metal implants, 40 representative images were selected from each group. Artifact index of each image was measured and calculated. Artifact level assessment through visual observation was performed by two radiologists in consensus. Analysis of variance and chi - square test were employed for statistical analysis of artifact index and artifact level on SPSS 13.0 software （ P 〈 0. 05 was considered significant difference. ） Results Analysis of variance showed that artifact index of t00keV mono - energy group was significantly lower than that of the mixture energy group （ P 〈 0. 05 ）. Chi - square test showed that there were significant differences between 100keV group and mixture energy as well as 65keV group （ P = 0. 000 ）. Conclusion Gemstone CT spectral imaging can obviously reduce the metal artifacts, and remarkably improve display capabilities of structures around the metallic implants.