Evaluation of Two Iterative Techniques for Reducing Metal Artifacts in Computed Tomography
Evaluation of Two Iterative Techniques for Reducing Metal Artifacts in Computed Tomography
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DOI：
10.1148/radiol.11101782
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发表时间：
2011-06-01
期刊：
影响因子：
19.7
通讯作者：
Fleischmann, Dominik
中科院分区：
文献类型：
--
作者：
Boas, F. Edward;Fleischmann, Dominik
目的：为了评估两种方法，减少金属伪影在计算机断层扫描（CT）-金属删除技术（MDT）和选择性代数重建技术（SART）-并比较这些方法与滤波反投影（FBP）和线性插值（LI）。材料和方法：机构审查委员会批准了这项回顾性的健康保险与责任法案兼容的研究，患者知情同意书被免除。模拟投影数据进行计算的体模，其中包含水，软组织，骨，和铁。临床投影数据是从11个连续识别的CT扫描与金属条纹伪影，共178个部分含有金属回顾性。使用FBP、LI、SART和MDT重建每次扫描。通过计算每个像素与原始体模相比的平均误差（Hounsfield单位），对模拟扫描进行定量评价。两名对所用重建算法不知情的放射科医师对临床扫描进行了定性评价，对每种算法的伪影总体严重程度进行了排名。P值的图像质量等级的比较计算从二项distribution.Results：模拟表明，MDT减少伪影由于光子饥饿，射束硬化，和运动，并没有引入新的金属和骨之间的条纹。MDT的平均误差最低（比FBP低76%，比LI低42%，比SART低17%）。临床扫描的盲法比较显示，MDT在100%的时间内具有最佳图像质量（95%置信区间：72%，100%）。LI的图像质量次之，SART和FBP的图像质量最差。从两个CT扫描的图像，扫描仪产生的图像相比，MDT揭示了潜在的临床importance.Conclusion信息：对于广泛的扫描，MDT产量减少金属条纹伪影和更好的图像质量比FBP，LI，或SART。(C)RSNA，2011年
Purpose: To evaluate two methods for reducing metal artifacts in computed tomography (CT)-the metal deletion technique (MDT) and the selective algebraic reconstruction technique (SART)-and compare these methods with filtered back projection (FBP) and linear interpolation (LI).Materials and Methods: The institutional review board approved this retrospective HIPAA-compliant study; informed patient consent was waived. Simulated projection data were calculated for a phantom that contained water, soft tissue, bone, and iron. Clinical projection data were obtained retrospectively from 11 consecutively identified CT scans with metal streak artifacts, with a total of 178 sections containing metal. Each scan was reconstructed using FBP, LI, SART, and MDT. The simulated scans were evaluated quantitatively by calculating the average error in Hounsfield units for each pixel compared with the original phantom. Two radiologists who were blinded to the reconstruction algorithms used qualitatively evaluated the clinical scans, ranking the overall severity of artifacts for each algorithm. P values for comparisons of the image quality ranks were calculated from the binomial distribution.Results: The simulations showed that MDT reduces artifacts due to photon starvation, beam hardening, and motion and does not introduce new streaks between metal and bone. MDT had the lowest average error (76% less than FBP, 42% less than LI, 17% less than SART). Blinded comparison of the clinical scans revealed that MDT had the best image quality 100% of the time (95% confidence interval: 72%, 100%). LI had the second best image quality, and SART and FBP had the worst image quality. On images from two CT scans, as compared with images generated by the scanner, MDT revealed information of potential clinical importance.Conclusion: For a wide range of scans, MDT yields reduced metal streak artifacts and better-quality images than does FBP, LI, or SART. (C) RSNA, 2011