System models used for iterative reconstruction affect the quality of computed tomography (CT) images. The imaging performance of the system models depends on the projectors, which implements forward- and back-projection. The system model based on a single projector is limited to improve image quality because each projector has both benefits and drawbacks. In this study, the effect of unmatched system models on iterative reconstruction was investigated by evaluating the image quality of reconstructed images. The unmatched system models composed of different projectors were used to perform iterative reconstruction. The image quality was evaluated in order to investigate the effect of the unmatched system models, and the imaging performance of the unmatched system models was compared with that of the matched system models by simulations and experiments with digital and anthropomorphic head phantoms. The results showed that the characteristics of CT images depended on the combinations of forward- and back-projectors, and the unmatched system models are able to improve the quality of the images obtained by using iterative reconstruction. The unmatched system models can be potentially used to improve the imaging performance of iterative reconstruction in CT systems.

中文翻译：

---

计算机断层扫描中不匹配系统模型对迭代重建的影响：幻影研究

用于迭代重建的系统模型会影响计算机断层扫描 (CT) 图像的质量。系统模型的成像性能取决于实施正投影和背投影的投影仪。基于单个投影仪的系统模型仅限于提高图像质量，因为每个投影仪都有优点和缺点。在这项研究中，通过评估重建图像的图像质量，研究了不匹配系统模型对迭代重建的影响。由不同投影仪组成的无与伦比的系统模型用于执行迭代重建。评估图像质量以研究不匹配系统模型的影响，并通过数字和拟人头部体模的模拟和实验，将未匹配系统模型的成像性能与匹配系统模型的成像性能进行比较。结果表明，CT图像的特征依赖于前向投影和后向投影的组合，不匹配的系统模型能够提高迭代重建图像的质量。不匹配的系统模型可以潜在地用于提高 CT 系统中迭代重建的成像性能。