点匹配空间配准中三种误差之间的关系  

Research on the Relationship of Three Kinds of Errors in Point Matching Spatial Registration

作　　者：王满宁[1] 

机构地区：[1]复旦大学基础医学院数字医学研究中心,上海市医学图像处理与计算机辅助手术重点实验室,上海市200032

出　　处：《组织工程与重建外科杂志》2014年第1期4-7,共4页Journal of Tissue Engineering and Reconstructive Surgery

摘　　要：目的基于标记点的点匹配方法普遍应用于计算机辅助手术的空间配准当中。点匹配中有标记点定位误差、标记点配准误差和靶点配准误差等三种误差定义方法,本实验着重研究这三种误差之间的关系及其对应用的影响。方法我们选择患者头颅CT数据进行空间配准的模拟试验,研究上述三种误差之间的关系。实验中我们使用几种不同的标记点数量,并且模拟了一个高斯分布和一个非高斯分布两种标记点定位误差模型。结果相同的标记点数量,标记点配准误差和靶点配准误差,都随着标记点定位误差的增加而增加。在相同的标记点定位误差分布模型下,标记点配准误差随着标记点数量的增加而增加,但是靶点配准误差随着标记点数量的增加而降低。在标记点定位误差符合相同高斯分布的情况下,标记点配准误差与靶点配准误差没有相关性,但是在标记点定位误差符合相同非高斯分布的情况下,两者之间表现出一定的相关性。结论在标记点数量不同的情况下,标记点配准误差不能用来衡量空间配准的情况。在标记点数量相同的情况下,标记点配准误差能否反应空间配准情况,则依赖于标记点定位误差的分布情况。Objective Point matching method is widely used in the spatial registration of computer assisted intervention system. There are three kinds of errors defined in point matching：fiducial localization error （FLE）, fiducial registration error （FRE）, and target registration error （TRE）. The relationship among these errors, and its impact on clinical application were studied in this article. Methods The CT image data was utilized to simulate the spatial registration in order to study the relationship among three kinds of errors. Different number of fiducial points and different models of the FLE （Gaussian model and non-Gaussian model） were used to conduct the simulation. Results Both the FRE and the TRE increased along with the increase of the magnitude of the FLE. Under the same FLE model, FRE increased but TRE decreased along with the increase of the number of fiducial points. When Gaussian model of FLE was used, the FRE and the TRE was uncorrelated. When the non-Gaussian model of FLE was used, the correlation coefficient between FRE and TRE was approximately 0.35. Conclusion When different number of fiducial points are used, the spatial registration accuracy cannot be compared according to the average TRE. When the same fiducial configuration is used, weather or not the average FRE reflects the accuracy of spatial registration depends on the underlying distribution model of the FLE.

关 键 词：点匹配 空间配准 计算机辅助手术 

分 类 号：R319[医药卫生—基础医学]