基于视图相关探测器位移的锥束CT模型迭代重建
Model-Based Iterative Reconstruction with View-Dependent Detector Displacements for Cone-Beam CT
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中文总结 AI 辅助
针对工业锥束CT中探测器非均匀移位问题，提出扩展可分离距离驱动MBIR模型，将视图相关探测器位移纳入重建，显著提升图像质量并减少伪影。
中文摘要 AI 辅助
探测器移位被用于工业锥束计算机断层扫描以减少环形伪影，但由此产生的探测器运动可能在不同投影视图间非均匀变化，并产生无法用固定偏移表示的探测器位置。尽管解析重建能够适应这种运动，但使用投影插值或重分箱的方法可能限制空间分辨率并引入伪影。MBIR通过将采集几何显式表示在重建模型中提供了一种替代方案。现有的可分离距离驱动MBIR公式假设探测器几何在投影视图间固定，因此无法直接表示两个探测器维度上的非均匀运动，因为这种运动改变了体素到探测器的映射。我们将可分离距离驱动的MBIR模型扩展，将记录的水平和垂直探测器位移纳入距离驱动重叠计算中，同时保持测量的投影不变。前向投影验证在1080个视图上实现了0.0338的NRMSE。所提出的模型实现了0.9404的3D SSIM和0.0406的NRMSE，而固定探测器MBIR分别为0.5396和0.1740。第二个工业数据集显示，与FDK相比，结构化伪影有所减少。
英文摘要
Detector shifting is used in industrial cone-beam computed tomography to reduce ring artifacts, but the resulting detector motion can vary nonuniformly across projection views and produce detector positions that cannot be represented by fixed offsets. Although analytical reconstruction can accommodate this motion, approaches that use projection interpolation or rebinning may limit spatial resolution and introduce artifacts. MBIR provides an alternative by representing the acquisition geometry explicitly within the reconstruction model. Existing separable distance-driven MBIR formulations assume fixed detector geometry across projection views and therefore cannot directly represent nonuniform motion in both detector dimensions, as this motion changes the voxel-to-detector mapping. We extend the separable distance-driven MBIR model to incorporate recorded horizontal and vertical detector displacements into the distance-driven overlap computation while leaving measured projections unchanged. Forward-projection validation achieved an NRMSE of 0.0338 across 1080 views. The proposed model achieved a 3D SSIM of 0.9404 and NRMSE of 0.0406, compared with 0.5396 and 0.1740 for fixed-detector MBIR. A second industrial dataset showed reduced structured artifacts compared with FDK.
发表机构
- Bredesen Center, University of Tennessee（田纳西大学布雷德森中心）
- Oak Ridge National Laboratory（橡树岭国家实验室）
- General Motors Research and Development（通用汽车研发）
机构由 AI 辅助整理，请以论文原文为准。
