Metal artifacts reduction using monochromatic images from spectral CT: Evaluation of pedicle screws in patients with scoliosis
Metal artifacts reduction using monochromatic images from spectral CT: Evaluation of pedicle screws in patients with scoliosis
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DOI：
10.1016/j.ejrad.2013.02.024
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发表时间：
2013-08-01
影响因子：
3.3
通讯作者：
Zhu, Bin
中科院分区：
文献类型：
--
作者：
Wang, Yang;Qian, Bangping;Zhu, Bin
目的：评价光谱CT在减少脊柱侧凸椎弓根螺钉金属伪影中的应用效果。材料和方法：获得机构审查委员会批准并获得患者的书面知情同意。本研究纳入了18例脊柱侧凸患者，共228枚椎弓根螺钉接受了光谱CT成像。使用80 kVp和140 kVp投影集，在65 keV和70 - 140 keV的光子能量范围内以10 keV的间隔生成带有和不带有额外金属伪影减少软件（MARS）校正的单色图像集。与对照组相同的扫描数据也产生了与常规140 kVp成像相对应的多色图像。进行客观评价（螺钉宽度和定量伪影指数测量）和主观评价（椎弓根螺钉、周围结构及其关系的描述）。结果：110 ~ 140 keV范围内单色图像的成像质量（0.97 +/- 0.28）优于常规多色图像（2.53 +/- 0.54），也优于能量较低的单色图像。能量超过100 keV的图像也可以精确测量螺钉的宽度和相对较低的伪影指数。在MARS重建中，螺钉的形状略有扭曲。结论：与传统的多色图像相比，双能CT获得的单色图像提供了更好的图像质量，大大减少了脊柱侧凸患者椎弓根螺钉的金属伪影。最佳能量范围为110 ~ 140 keV。爱思唯尔爱尔兰有限公司版权所有版权所有。
Purpose: To evaluate the effectiveness of spectral CT in reducing metal artifacts caused by pedicle screws in patients with scoliosis.Materials and methods: Institutional review committee approval and written informed consents from patients were obtained. 18 scoliotic patients with a total of 228 pedicle screws who underwent spectral CT imaging were included in this study. Monochromatic image sets with and without the additional metal artifacts reduction software (MARS) correction were generated with photon energy at 65 keV and from 70 to 140 keV with 10 keV interval using the 80 kVp and 140 kVp projection sets. Polychromatic images corresponded to the conventional 140 kVp imaging were also generated from the same scan data as a control group. Both objective evaluation (screw width and quantitative artifacts index measurements) and subjective evaluation (depiction of pedicle screws, surrounding structures and their relationship) were performed.Results: Image quality of monochromatic images in the range from 110 to 140 keV (0.97 +/- 0.28) was rated superior to the conventional polychromatic images (2.53 +/- 0.54) and also better than monochromatic images with lower energy. Images of energy above 100 keV also give accurate measurement of the width of screws and relatively low artifacts index. The form of screws was slightly distorted in MARS reconstruction.Conclusions: Compared to conventional polychromatic images, monochromatic images acquired from dual-energy CT provided superior image quality with much reduced metal artifacts of pedicle screws in patients with scoliosis. Optimal energy range was found between 110 and 140 keV. Crown Copyright (C) 2013 Published by Elsevier Ireland Ltd. All rights reserved.