Reduction of metal artifacts due to dental hardware in computed tomography angiography: assessment of the utility of model-based iterative reconstruction
Reduction of metal artifacts due to dental hardware in computed tomography angiography: assessment of the utility of model-based iterative reconstruction
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DOI：
10.1007/s00234-017-1811-5
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发表时间：
2017-03-01
期刊：
影响因子：
2.8
通讯作者：
Ogawa, Toshihide
中科院分区：
文献类型：
--
作者：
Kuya, Keita;Shinohara, Yuki;Ogawa, Toshihide
本研究的目的是评估自适应统计迭代重建（ASIR）和基于模型的迭代重建（MBIR）在颈动脉CT血管造影（CTA）中减少牙科硬件造成的金属伪影的价值。方法对37例行颈动脉CTA的牙科硬体患者进行分析。使用GE Discovery CT750 HD扫描仪进行CTA，并使用滤波后投影（FBP）、ASIR和MBIR进行重建。我们测量了受牙科金属假物影响最大的颈内动脉颈段的标准差（SD1）和未受假物影响的颈总动脉的标准差（SD2）。我们计算人工指标（AI）如下：AI = [(SD1)2 -(SD2)2]1/2，并比较每个AI的FBP、ASIR和MBIR。内颈动脉的视觉评估也由两名神经放射学家进行，对每个轴位和重建矢状位图像使用五分制。采用加权kappa分析对观察者间的一致性进行分析。结果与FBP和ASIR相比，MBIR显著改善了AI （p < 0.001）。我们发现FBP和ASIR之间的AI无显著差异（p = 0.502）。MBIR评分显著优于FBP和ASIR (p < 0.001)，而ASIR评分与FBP评分相同。Kappa值显示所有重建图像的观察者间一致性良好（0.747-0.778）。结论：在颈动脉CTA中，MBIR可显著减少牙齿硬体造成的假影。
Purpose The aim of this study is to assess the value of adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) for reduction of metal artifacts due to dental hardware in carotid CT angiography (CTA).Methods Thirty-seven patients with dental hardware who underwent carotid CTA were included. CTA was performed with a GE Discovery CT750 HD scanner and reconstructed with filtered back projection (FBP), ASIR, and MBIR. We measured the standard deviation at the cervical segment of the internal carotid artery that was affected most by dental metal artifacts (SD1) and the standard deviation at the common carotid artery that was not affected by the artifact (SD2). We calculated the artifact index (AI) as follows: AI = [(SD1)2 -(SD2)2]1/2 and compared each AI for FBP, ASIR, and MBIR. Visual assessment of the internal carotid artery was also performed by two neuroradiologists using a five-point scale for each axial and reconstructed sagittal image. The inter-observer agreement was analyzed using weighted kappa analysis.Results MBIR significantly improved AI compared with FBP and ASIR (p < 0.001, each). We found no significant difference in AI between FBP and ASIR (p = 0.502). The visual score of MBIR was significantly better than those of FBP and ASIR (p < 0.001, each), whereas the scores of ASIR were the same as those of FBP. Kappa values indicated good inter-observer agreements in all reconstructed images (0.747-0.778).Conclusions MBIR resulted in a significant reduction in artifact from dental hardware in carotid CTA.