Successive iterative restoration applied to streak artifact reduction in X-ray CT image of dento-alveolar region
Successive iterative restoration applied to streak artifact reduction in X-ray CT image of dento-alveolar region
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DOI：
10.1007/s11548-010-0544-2
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发表时间：
2011-09-01
影响因子：
3
通讯作者：
Hayakawa, Yoshihiko
中科院分区：
文献类型：
--
作者：
Dong, Jian;Kondo, Atsushi;Hayakawa, Yoshihiko
目的：由于条纹伪影的出现，牙槽骨区域的X射线计算机断层扫描（CT）图像有时无法用于诊断目的。本研究的目的是减少条纹伪影出现在牙科和颌面部X线CT图像的应用程序的修改迭代restorationmethod.Methods我们利用了这方面，相邻的CT图像往往描绘非常相似的解剖结构内的薄层图像的集合。使用相邻CT图像的投影数据处理具有条纹伪影的CT图像。一种改进的迭代校正，最大似然-期望最大化（ML-EM）重建算法，用于减少口腔金属材料引起的条纹伪影。它在处理后的图像和原始投影数据之间进行近似。首先，获得完整图像的投影数据，然后，处理具有条纹伪影的下一图像。获得处理后图像的投影数据，并将ML-EM方法再次应用于下一图像。结果共处理了12幅相邻图像。每次迭代恢复进行50次。结论改进的ML-EM方法能有效地减少牙槽骨CT图像中的条纹伪影，并能有效地消除牙槽骨CT图像中的条纹伪影。
Purpose X-ray computed tomography (CT) images in the dento-alveolar region are sometimes rendered unusable for diagnostic purposes due to the appearance of streak artifacts. The purpose of the study is to reduce streak artifacts appeared on dental and maxillofacial X-ray CT images by the application of modified iterative restoration method.Methods We took advantage of the aspect that adjacent CT images often depict very similar anatomical structures within the resulting collection of thin-slice images. CT images having streak artifacts were processed using the projection data of adjacent CT images. A modified iterative correction, the maximum likelihood-expectation maximization (ML-EM) reconstruction algorithm, was employed to reduce the streak artifact caused by metallic materials in the oral cavity. It approximates between the processed image and the original projection data. First, the projection data of an intact image were obtained, and then, the next image that had streak artifacts was processed. The projection data of the processed image were obtained, and the ML-EM method was applied to the next image again. Then, the successive iterative restoration was carried out.Results Twelve adjacent images were processed. Each iterative restoration was carried out fifty times. Streak artifacts were observed on processed images at the initial stage, but some of them either suppressed or disappeared as the iteration progressed.Conclusions The modified ML-EM method was effective to reduce streak artifacts in X-ray CT images in dento-alveolar region.