A Gaussian approach for the calculation of the accuracy of stereotactic frame systems
A Gaussian approach for the calculation of the accuracy of stereotactic frame systems
复制标题
计算立体定向框架系统精度的高斯方法
DOI：
10.1118/1.598529
复制
发表时间：
1999
期刊：
影响因子：
3.8
通讯作者：
G. Schmitz
中科院分区：
文献类型：
--
作者：
W. Zylka;J. Sabczynski;G. Schmitz
立体定向框架系统广泛应用于神经外科。框架装置的精度被认为是比较新型无框架立体定向导航系统精度的金标准。本研究的目的是发展一种预测立体定向系统应用精度的通用方法。该方法将应用于三种框架装置：Leksell G、Cosman-Roberts-Wells （CRW）和Brown-Roberts-Wells （BRW）进行的基于框架的活检。将进行工作流程分析，证明与临床应用相关的准确性包括几个误差源，包括成像，目标和入口点选择，图像到框架坐标的配准以及框架机械参数的设置。假设这些误差源服从高斯分布概率密度。线性，即高斯误差传播，将用于连接所有误差贡献，从而计算应用程序中使用的帧的累积精度。虽然高斯方法是一种近似值，但它允许对精度进行解析处理。研究了目标点的精度和测针沿规划轨迹的制导精度。具有重要意义的是发现精度、像素尺寸和图像切片厚度之间的关系，后者是超过1.5 mm厚度的切片的主要因素，导致误差大于1.5 mm。对目标点的应用精度预测与实测结果进行了比较，结果与实验数据吻合较好。
Stereotactic frame systems are widely used in neurosurgery. The accuracy of frame devices is considered as a gold standard to which the accuracy of new frameless stereotactic navigation systems is compared. The purpose of this study is to develop a general approach for the prediction of the application accuracy of stereotactic systems. The approach will be applied to the frame-based biopsy performed with three frame devices: Leksell G, Cosman–Roberts–Wells (CRW), and Brown–Roberts–Wells (BRW). A work-flow analysis will be carried out demonstrating that the accuracy relevant for a clinical application comprises several error sources including imaging, target and entry point selection, image to frame coordinates registration, and the setting of mechanical parameters of the frame. These error sources will be postulated to obey a Gaussian distribution probability density. The linear, i.e., Gaussian, error propagation, will be used to link all error contributions thus to calculate the cumulative accuracy of the frame used in the application. Although the Gaussian approach is an approximation, it allows for an analytical treatment of the accuracy. Both the accuracy at the target point and the accuracy of the probe needle guidance along the planned trajectory have been investigated. Of great significance is the relationship found between accuracy, pixel dimension, and image slice thickness, the latter being the dominant factor for slices of more than 1.5 mm thickness, yielding inaccuracies larger than 1.5 mm. For target points the predictions for the application accuracy have been compared to the results of measurements, showing good agreement with the experimental data.