基于一种体模对能谱CT去除金属伪影的研究

Removal of Metal Artifacts by Energy Spectrum CT Based on a Phantom

目的通过利用GE 750HD CT对原型体模进行扫描试验,探讨能谱CT的去金属伪影能力。方法扫描实验分3组完成:第一组采用传统临床上最常用管电压为的120 k Vp的螺旋CT扫描;第二组采用能谱采集扫描单能量成像(Monoenergetic,MONO)模式;第三组把GSI Viewer重建的6组单能量图像数据结合多伪影去除技术(Multi Artifact Reduction System,MARS)再进行重建。利用伪影指数AI对伪影图像进行客观分析。结果 MONO及MARS模式下的图像无论在何种条件下,其AI值均显著低于其它两种模式图像的AI值;MONO图像质量比120 k Vp模式的图像质量好。MONO及MARS图像噪声明显低于120 k Vp模式的图像和MONO图像。结论能谱成像技术对去处金属伪影是一个有效的途径,若后期再添加一些去除金属伪影的算法,如MARS技术,效果会更好。

Objective To discuss the ability of removing the metal artifact of spectrum CT by using GE 750HD CT to scan the phantom.Methods Scanning experiments were divided into three groups:the first group was performed a tube voltage of 120 kVp spiral scan,the most commonly used in the traditional clinical;the second groups was performed monoenergetic(MONO)scanning energy spectral acquisition mode;in the third group,6 groups of single energy image data that reconstructed by the GSI Viewer was combined with multi artifact reduction system(MARS)technology and reconstructed.The artifact image artifact was analyzed objectively by using index AI.Results Under the condition of MONO&MARS,the AI value of the image was lower than that of the other two modes,and the MONO image quality was better than that of the 120 kVp mode image.The image noise of MONO&MARS was obviously lower than that of 120 kVp mode and MONO image.Conclusion Spectral imaging technology is a good way to locate metal artifacts.It would be better to add some algorithms for removing metal artifacts,such as MARS.