Efficient 2D filtering for cone-beam VOI reconstruction
Efficient 2D filtering for cone-beam VOI reconstruction
复制标题
用于锥束 VOI 重建的高效 2D 滤波
DOI：
10.1109/nssmic.2012.6551549
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
J. Hornegger
中科院分区：
文献类型：
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作者：
Yan Xia;A. Maier;F. Dennerlein;H. Hofmann;J. Hornegger
在一些临床应用中，例如，在介入期间检查展开的支架或线圈时，只有一小部分患者可能具有诊断意义。为了减少对患者的剂量，部署准直器以阻挡感兴趣体积（VOI）外的辐射剂量是可行的。然而，由此产生的截断，特别是在横向方向上，对传统的重建方法提出了挑战。近似截断鲁棒计算机断层扫描算法（ATRACT）能够重建图像，而不使用任何显式的外推计划，即使是高度截断的数据。它基于将标准斜坡滤波器分解为局部和非局部滤波步骤，其中局部步骤与二维（2D）拉普拉斯算子一致，而非局部步骤是基于2D Radon的滤波。在实际实现中，基于Radon的滤波在计算上不是高效的。在本文中，我们提出了一个改进的原始ATRACT算法。原始算法中的基于2D Radon的滤波步骤被解析2D卷积取代，从而在保留VOI算法的图像质量益处的同时显著提高了计算性能。
In some clinical applications, e.g., examination of deployed stents or coils during the intervention, only a small portion of the patient may be of diagnostic interest. For the sake of dose reduction to the patient, it is practicable to deploy a collimator to block radiation dose outside volume of interest (VOl). The resulting truncation, however, particularly in lateral direction, poses a challenge to the conventional reconstruction methods. The Approximated Truncation Robust Algorithm for Computed Tomography (ATRACT) is able to reconstruct images without the use of any explicit extrapolation schemes, even for highly truncated data. It is based on a decomposition of the standard ramp-filter into a local and a non-local filtering step, where the local step coincides with the two-dimensional (2D) Laplace operator and the non-local step is a 2D Radon-based filtering. In a practical implementation, the Radon-based filtering is not computationally efficient. In this paper, we present an improvement of the original ATRACT algorithm. The 2D Radon-based filtering step in the original algorithm is replaced by an analytical 2D convolution, resulting in a significant improvement in computational performance while retaining the image quality benefits of the VOl algorithm.