Adaptive spatial calibration of a 3D ultrasound system
Adaptive spatial calibration of a 3D ultrasound system
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DOI：
10.1118/1.3373520
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发表时间：
2010-05-01
期刊：
影响因子：
3.8
通讯作者：
Roberts, David
中科院分区：
文献类型：
--
作者：
Hartov, Alex;Paulsen, Keith;Roberts, David
方法：校准方法基于相对于 3D 跟踪系统的未知位置的固定平面的图像。这种方法的优点是消除了作为误差源的平面位置测量。所设计的方法足够通用，并且适用于使用相同的方法校准 2D 图像和 3D 体积集的扫描头。两种类型扫描头的基本算法相同，一旦收集到数据，就可以在无人值守的情况下全自动运行。该方法是通过为每个所需步骤寻找最简单、最可靠的解决方案而设计的。这些是图像或体积内平面相交的识别以及用于计算校准变换矩阵的优化方法。作者在这两个步骤中使用自适应算法来消除可能妨碍程序收敛的数据，从而有助于该方法的稳健性。 结果：作者在两个扫描头上运行了总计 57 次校准运行的测试，在所有可用的尺度上产生 3D 成像体积。作者根据两个标准对该系统进行了评估：稳健性和准确性。对于每一项测试，程序都在无人值守的情况下收敛到有用值 (100%)。根据参考平面的测量位置，对于所有组合测试，其精度估计为 0.7 +/- 0.6 毫米。结论：所提出的系统非常稳健，并且允许基于 2D 或 3D 成像系统无人值守地计算徒手跟踪超声所需的校准参数。
Methods: The method of calibration is based on images of a fixed plane of unknown location with respect to the 3D tracking system. This approach has, for advantage, to eliminate the measurement of the plane location as a source of error. The devised method is sufficiently general and adaptable to calibrate scanheads for 2D images and 3D volume sets using the same approach. The basic algorithm for both types of scanheads is the same and can be run unattended fully automatically once the data are collected. The approach was devised by seeking the simplest and most robust solutions for each of the steps required. These are the identification of the plane intersection within the images or volumes and the optimization method used to compute a calibration transformation matrix. The authors use adaptive algorithms in these two steps to eliminate data that would otherwise prevent the convergence of the procedure, which contributes to the robustness of the method.Results: The authors have run tests amounting to 57 runs of the calibration on two a scanhead that produce 3D imaging volumes, at all the available scales. The authors evaluated the system on two criteria: Robustness and accuracy. The program converged to useful values unattended for every one of the tests (100%). Its accuracy, based on the measured location of a reference plane, was estimated to be 0.7 +/- 0.6 mm for all tests combined.Conclusions: The system presented is robust and allows unattended computations of the calibration parameters required for freehand tracked ultrasound based on either 2D or 3D imaging systems.