Quantitative evaluation of metal artifacts using different CBCT devices, high-density materials and field of views
Quantitative evaluation of metal artifacts using different CBCT devices, high-density materials and field of views
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DOI：
10.1111/clr.13019
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发表时间：
2017-12-01
影响因子：
4.3
通讯作者：
Jacobs, Reinhilde
中科院分区：
文献类型：
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作者：
Codari, Marina;Vasconcelos, Karla de Faria;Jacobs, Reinhilde
目的客观比较不同锥束CT（cone-beam computed tomography，CBCT）设备、高密度材料和视野（fieldofviews，FOV）对金属伪影表达的影响。使用高分辨率协议、相同体素尺寸（0.2mm）和不同FOV在三个CBCT设备上扫描钛、铜铝合金和汞合金。在全自动分割和图像配准之后，针对小视场和中等视场定义相同的感兴趣区域。评估金属圆柱体的分割体积和真实的体积之间的差异。此外，对于每个分割的切片，确定分割的和真实的轴向截面之间的面积差。背景上的文物进行测量，作为归一化标准偏差的体素值在附近的圆柱体，在三个不同的distance.ResultsConsiderable差异观察到所有CBCT设备和材料的FOV大小（高达67%）的体积测量。切片/切片面积分析表明金属圆柱体边缘处的伪影较高。在所有CBCT器械中，汞合金和钛分别具有最差和最好的伪影表达。标准差值在每种设备的三个距离之间的变化不同。结论我们的体外研究表明，不同的CBCT设备，高密度材料和FOV应被考虑，同时评估CBCT图像。更谨慎的是，诊断结论应在含有汞合金和铜铝合金的图像中得出。
ObjectiveTo objectively compare the influence of different cone-beam computed tomography (CBCT) devices, high-density materials and field of views (FOVs) on metal artifact expression.Material and methodsFor this invitro study, three customized acrylic resin phantoms containing high-density materials cylinders: titanium, copper-aluminum alloy and amalgam were scanned on three CBCT devices using high-resolution protocols, same voxel size (0.2mm) and different FOVs. After fully automatic segmentation and image registration, the same region of interest was defined for the small and medium FOVs. The difference between the segmented and the real volume of the metal cylinders was assessed. Moreover for each segmented slice, the area difference between the segmented and the real axial section was determined. The artifacts on the background were measured as normalizing standard deviation of voxel values in the vicinity of the cylinder, in three different distances.ResultsConsiderable differences were observed in volume measurements for all CBCTs devices and materials for both FOV sizes (up to 67%). The slice per slice area analysis indicated higher artifacts at the edges of the metal cylinder. Within the materials, amalgam and titanium had, respectively, the worst and best artifact expression in all the CBCT devices. Standard deviation values varied differently between the three distances in each device.ConclusionOur invitro study showed that different CBCT devices, high-density materials and FOV should be considered while evaluating CBCT images. More carefully, diagnosis conclusions should be drawn in images containing amalgam and copper-aluminum alloy.