In conventional industrial computed tomography, the source–detector system rotates in equiangular steps in-plane relative to the part of investigation. While being by far the most frequently used acquisition trajectory today, this method has several drawbacks like the formation of cone beam artefacts or limited usability in case of geometrical restrictions. In such cases, the usage of alternative spherical trajectories can be beneficial to improve image quality and defect visibility. While investigations have been performed to relate the influence of the trajectory choice in the typical metrological case of a high number of available projections, so far barely any work has been done for the case of few source–detector poses, which is more relevant in the field of non-destructive testing. In this work, we provide an overview of quantitative metrics that can be used to assess the image quality of reconstructed computed tomography volumes, discuss their advantages and drawbacks and propose a framework to investigate the performance of several non-standard trajectories with respect to previously defined regions of interest. Inspired by pseudorandom sampling methods for Monte–Carlo-algorithms, we also suggest an entirely new trajectory design, the low-discrepancy spherical trajectory, which extends the concept of equiangular planar trajectories into three dimensions and can be used for benchmarking and comparison with other spherical trajectories. Last, we use an optimization method to calculate task-specific acquisition trajectories and relate their performance to other spherical designs.

在传统的工业计算机断层扫描中，源探测器系统相对于调查部分在平面内以等角步长旋转。虽然是目前最常用的采集轨迹，但这种方法有几个缺点，如锥形束假象的形成或在几何限制的情况下可用性有限。在这种情况下，使用替代的球面轨迹有助于提高图像质量和缺陷可见性。虽然已经进行了大量可用投影的典型计量案例中轨迹选择的影响的调查，但到目前为止，几乎没有对少数源探测器位姿的情况进行任何工作，这在无损检测领域。在这项工作中，我们概述了可用于评估重建计算机断层扫描体积的图像质量的定量指标，讨论它们的优缺点，并提出了一个框架来研究几个非标准轨迹相对于先前定义的感兴趣区域的性能。受蒙特卡罗算法的伪随机采样方法的启发，我们还提出了一种全新的轨迹设计，即低差异球面轨迹，它将等角平面轨迹的概念扩展到三个维度，可用于基准测试和与其他球面轨迹的比较。轨迹。最后，我们使用优化方法来计算特定任务的采集轨迹，并将它们的性能与其他球形设计相关联。