Metal Artifact Reduction in Computed Tomography After Deep Brain Stimulation Electrode Placement Using Iterative Reconstructions
Metal Artifact Reduction in Computed Tomography After Deep Brain Stimulation Electrode Placement Using Iterative Reconstructions
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DOI：
10.1097/rli.0000000000000296
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发表时间：
2017-01-01
影响因子：
6.7
通讯作者：
Thomas, Christoph
中科院分区：
文献类型：
--
作者：
Aissa, Joel;Boos, Johannes;Thomas, Christoph
目的：术中计算机断层扫描（CT）在深部脑刺激（DBS）电极置入后的诊断准确性受到金属硬件诱发的伪影的限制，这可能掩盖颅内术后并发症。不同的金属伪影抑制技术被引入来减少CT中金属硬件产生的伪影。本研究的目的是评估一种新的迭代MAR技术对DBS电极实施手术患者随访时图像质量和诊断性能的影响。材料与方法：回顾性分析2015年3月至2015年6月17例DBS电极植入后行术中常规头部CT检查的患者。所有患者的原始数据均采用标准加权滤波后投影（WFBP）和一种新的迭代MAR算法进行重构。我们量化了密度变化的频率来评估量化伪影的减少。为了评价定性图像质量，根据4分制对众多脑解剖标志的可见性和颅内电极的可检测性进行评分。此外，对总体和邻近电极的伪影强度进行了评定。结果：我们的定量伪影减少结果表明，与WFBP（整体低频值，4487.3 +/- 875.4，范围，2218.3-5783.5）重建图像相比，迭代MAR （iMAR）重建图像的金属伪影（整体低频值，1608.6 +/- 545.5，范围，375.5-3417.2）显著降低（P < 0.004）。定性图像分析显示，与WFBP（整体解剖标志，2.49 +/- 0.15；中位数，3；范围，0-3；整体电极特征，2.35 +/- 0.16；中位数，2；范围，0-3；伪影特征，2.16 +/- 0.08；中位数，2.5；范围，0-3）相比，iMAR的图像质量显著提高(整体解剖标志，1.21 +/- 0.64；中位数，1；范围，0-3；整体电极特征，0.74 +/- 0.37；中位数，1；范围，0-2；伪影特征，0.51 +/- 0.15；值,0.5;范围0 - 2;P < 0.002)。结论：与WFBP重建相比，使用新型iMAR算法重建DBS植入后患者的颅骨CT图像可以有效减少DBS电极附近的金属伪影。我们证明了与DBS电极患者的WFBP相比，iMAR的定量和定性图像质量得到了改善。
Objectives: Diagnostic accuracy of intraoperative computed tomography (CT) after deep brain stimulation (DBS) electrode placement is limited due to artifacts induced by the metallic hardware, which can potentially mask intracranial postoperative complications. Different metal artifact reduction (MAR) techniques have been introduced to reduce artifacts from metal hardware in CT. The purpose of this study was to assess the impact of a novel iterative MAR technique on image quality and diagnostic performance in the follow-up of patients with DBS electrode implementation surgery.Materials and Methods: Seventeen patients who had received routine intraoperative CT of the head after implantation of DBS electrodes between March 2015 and June 2015 were retrospectively included. Raw data of all patients were reconstructed with standard weighted filtered back projection (WFBP) and additionally with a novel iterative MAR algorithm. We quantified frequencies of density changes to assess quantitative artifact reduction. For evaluation of qualitative image quality, the visibility of numerous cerebral anatomic landmarks and the detectability of intracranial electrodes were scored according to a 4-point scale. Furthermore, artifact strength overall and adjacent to the electrodes was rated.Results: Our results of quantitative artifact reduction showed that images reconstructed with iterative MAR (iMAR) contained significantly lower metal artifacts (overall low frequency values, 1608.6 +/- 545.5; range, 375.5-3417.2) compared with the WFBP (overall low frequency values, 4487.3 +/- 875.4; range, 2218.3-5783.5) reconstructed images (P < 0.004). Qualitative image analysis showed a significantly improved image quality for iMAR (overall anatomical landmarks, 2.49 +/- 0.15; median, 3; range, 0-3; overall electrode characteristics, 2.35 +/- 0.16; median, 2; range, 0-3; artifact characteristics, 2.16 +/- 0.08; median, 2.5; range, 0-3) compared with WFBP (overall anatomical landmarks, 1.21 +/- 0.64; median, 1; range, 0-3; overall electrode characteristics, 0.74 +/- 0.37; median, 1; range, 0-2; artifact characteristics, 0.51 +/- 0.15; median, 0.5; range, 0-2; P < 0.002).Conclusions: Reconstructions of cranial CT images with the novel iMAR algorithm in patients after DBS implantation allows an efficient reduction of metal artifacts near DBS electrodes compared with WFBP reconstructions. We demonstrated an improvement of quantitative and qualitative image quality of iMAR compared with WFBP in patients with DBS electrodes.