摘要
目的探究能谱CT去金属伪影技术(MAR)去除脊柱椎弓根钉伪影的适宜keV范围。方法对41例脊柱椎弓根钉术后的患者行能谱CT检查,获取的扫描数据以每隔10 keV重组出70~140 keV共8组MAR图像。比较不同keV条件下椎弓根钉后方、侧方软组织和椎管内的CT值及其标准差(SD)、伪影指数(AI),同时对骨结构、椎管内和椎旁软组织显影进行主观评价,并进行统计学分析。结果70~140 keV共8组MAR图像中,随着keV的递增,椎弓根钉后方、侧方软组织的CT值递增,椎管内的CT值递减;椎弓根钉后方、侧方软组织和椎管内的SD值、AI值均递减。用R软件绘制出CT值、SD值、AI值随keV变化的曲线,最大选择检验法得到的所有曲线拐点均位于100 keV水平,即在70~100 keV曲线变化陡峭,在110~140 keV曲线趋于平缓。主观评价中,骨结构、椎管和椎旁软组织显影的得分随着keV的递增而增加,在110~140 keV主观平均得分>3分。结论MAR技术可以有效地减少脊柱椎弓根钉伪影,并且110~140 keV是较适宜的keV范围。
Objective To investigate the suitable keV of spectral CT MAR(Multi Artifact Reduction)on removing artifacts from spin pedicle screws.Methods 41 patients with spinal pedicle screws underwent spectral CT examination.Postoperative images were reconstructed at 70-140 keV interval 10 keV.The values of CT、standard deviation(SD)and artifact index(AI)of the posterior、lateral soft tissue of pedicle screws and spinal canal were compared at different keV.Visibility of vertebral canal and the paravertebral soft tissue,definition of bony structures were subjectively evaluated and compared with statiatics.Results In the all MAR images from 70 to 140 keV,with the increase of keV,the value of CT of posterior and lateral soft tissues of the pedicle screws increased,and the value of CT in the spinal canal decreased.The mean SD and AI of posterior、lateral soft tissue of the pedicle screw and the spinal canal all decreased.The CT,SD and AI varied with keV were plotted by R software and the inflection points of all curves were obtained at 100 keV by the maximum selection test.That is,the curve changes steeply between 70-100 keV,but smoothly between 110-140 keV.In the subjective evaluation,the scores of bone structure,spinal canal and paravertebral soft tissue increased with increasing keV,the average score was>3 points between 110-140 keV.Conclusion MAR can effectively reduce the artifact of pedicle screws and 110-140 keV were suitabl.
作者
李杰
李楠
袁源
袁慧书
LI Jie;LI Nan;YUAN Yuan(Department of Radiology,Peking University Third Hospital,Beijing 100191,P.R.China)
出处
《临床放射学杂志》
CSCD
北大核心
2020年第6期1144-1148,共5页
Journal of Clinical Radiology
