口腔全景锥形束CT图像重建算法  

Reconstruction algorithm for dental panorama based on cone beam CT image

作　　者：万俊[1] 王远军[1] 王丽嘉[1] 聂生东[1] 

机构地区：[1]上海理工大学医学影像工程研究所,上海200093

出　　处：《中国医学物理学杂志》2016年第5期437-441,共5页Chinese Journal of Medical Physics

基　　金：国家自然科学基金(60972122;61201067);上海市自然科学基金(14ZR1427900);上海市教委科研创新项目(13YZ069)

摘　　要：在利用口腔锥形束CT的三维图像数据自动重建全景图时,如果锥形束CT图像中病人上、下颌骨的咬合平面不能保持水平,已有的算法将不能重建口腔全景图。为解决这一问题,本文提出一种新的全自动方法。仿照传统口腔X线全景机的成像机制,首先,在沿冠状轴的最大密度投影图像中计算出偏差角度,再旋转三维数据场;然后,在沿垂直轴的最大密度投影图像上分割牙弓区域,根据该牙弓区域就能拟合出重建全景图所需的牙弓线;最后,离散化牙弓线并沿垂直轴扩展,得到离散化的牙弓曲面,再采样合成全景图。实验结果表明本文方法较好地解决了因上、下颌骨的咬合平面不能保持水平而引起的几何畸变,从而很好地重建出口腔全景图。When dental panorama was automatically reconstructed based on the three-dimensional image data of cone beam CT images, the existing algorithms could not reconstruct the dental panorama if the occlusal plane of maxilla and mandibule in cone beam CT image did not parallel to the horizontal plane. A new automatic method was proposed in the paper to solve the problem. According to the imaging principle of conventional dental panoramic radiograph, the deviation angle in the maximum intensity projection image along the coronal axis was firstly calculated, and the three-dimensional data field was rotated. Secondly, the dental arch region in the maximum intensity projection image along the vertical axis was segmented,and the dental arch curve which was required for the panorama reconstruction was fitted based on the dental arch region.Finally, the dental arch curve was discretized and extended along the vertical axis to obtain the discretized dental arch surface, and the panorama was synthesized by re-sampling. Massive experiments have proved the proposed algorithm can solve the problem of geometric distortion caused by the occlusal plane of maxilla and mandibule which doesn＇t parallel to horizontal plane, and reconstruct the dental panorama well.

关 键 词：锥形束CT 口腔 牙弓 全景图 X线全景影像技术 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术] R445.3[自动化与计算机技术—计算机科学与技术]