目的 探讨颈椎金属内固定术后，金属伪影校正（Metal Artifact Correction，MAC）技术在降低CT金属伪影的临床 价值。方法 随机选择金属内固定术后颈椎CT复查患者106例，将原始数据用两种方式重建，A组用KARL迭代重建技术，B组 用MAC技术，分别对A、B两组图像的CT值、噪声标准差（Standard Deviation，SD）测量，计算信噪比（Signal to Noise Ratio，SNR）、对比噪声比（Contrast to Noise Ratio，CNR）。由2名经验丰富的放射科医师采用双盲法对A、B组图像行主 观评价。结果 根据各测量点CT值、SD值的中位数及其上下四分位数推断，高密度伪影点CT值、SD值A组均高于B组，低 密度伪影点CT值A组低于B组，SD值A组高于B组，差异均有统计学意义（P<0.05）丨软组织测量点A、B组CT值、SD值的 差异无统计学意义（P>0.05）。各测量点的SNR、CNR以及主观评分，A组均低于B组，差异有统计学意义（P<0.05）。结 论 颈椎金属内固定术后CT复查，对原始图像采用MAC技术重建可明显降低内固定的金属伪影，不仅能获得较好的图像质 量，而且能提高CT检查的流通量。

Objective To explore the clinical value of metal artifact correction (MAC) technology in reducing CT metal artifacts after cervical metal internal fixation implantation. Methods A total of 106 patients who underwent cervical CT reexamination after cervical metal internal fixation implantation were randomly selected. The original data were reconstructed in two ways. Group A used KARL iterative image reconstruction technique, and group B was reconstructed using MAC technology. The CT value and noise value standard deviation (SD) of A and B images were measured respectively, and the signal to noise ratio (SNR) and contrast to noise ratio (CNR) were calculated. Two experienced radiologists used double-blind method to subjectively evaluate the images of group A and B. Results Based on CT value, the median SD value, its upper and lower quartile of each measurement point, the CT and SD value of high-density artifact point of group A were higher than that of group B丨 the CT value of low-density artifact point of group A was lower than that of group B, and the SD value of group A was higher than that of group B丨 the differences were statistically significant (P<0.05). There was no statistical significant difference in CT value and SD value between the soft tissue measurement points of group A and B (P>0.05). The SNR, CNR and subjective scores of group A were all lower than those of group B, with statistical significant differences (P<0.05). Conclusion For the CT reexamination after cervical metal internal fixation implantation, MAC reconstruction of original images can significantly reduce the metal artifacts generated by internal fixation, which can not only obtained from better image quality, but also improve the flux of CT examination.