Iterative 4D cardiac micro-CT image reconstruction using an adaptive spatio-temporal sparsity prior
Iterative 4D cardiac micro-CT image reconstruction using an adaptive spatio-temporal sparsity prior
复制标题
DOI：
10.1088/0031-9155/57/6/1517
复制
发表时间：
2012-03-21
影响因子：
3.5
通讯作者：
Kachelriess, Marc
中科院分区：
文献类型：
--
作者：
Ritschl, Ludwig;Sawall, Stefan;Kachelriess, Marc
时间相关的图像重建，也称为4D CT图像重建，是计算机断层扫描中的一个很大的挑战。将时域结合到重建中的原因是扫描对象的运动，否则这将导致运动伪影。4D CT图像重建的标准方法是提取单个运动相位并分别进行重建。由于每个阶段中使用的投影数量较少，这些重建可能会受到欠采样伪影的影响。有不同的迭代方法，试图结合一些先验知识，以补偿这些文物。在本文中，我们将遵循这一策略。我们使用的成本函数是一个更高的维度成本函数，占在空间和时间方向上的测量信号的稀疏性。这导致了更高维的全变差的定义。使用体内心脏微CT小鼠数据验证该方法。此外，我们比较的结果，相位相关的重建使用FDK算法和总变差约束重建，其中总变差项仅在空间域中定义。与其他方法相比，重建的数据集在伪影减少和低对比度分辨率方面显示出很大的改进。因此，重构信号的时间分辨率不受影响。
Temporal-correlated image reconstruction, also known as 4D CT image reconstruction, is a big challenge in computed tomography. The reasons for incorporating the temporal domain into the reconstruction are motions of the scanned object, which would otherwise lead to motion artifacts. The standard method for 4D CT image reconstruction is extracting single motion phases and reconstructing them separately. These reconstructions can suffer from undersampling artifacts due to the low number of used projections in each phase. There are different iterative methods which try to incorporate some a priori knowledge to compensate for these artifacts. In this paper we want to follow this strategy. The cost function we use is a higher dimensional cost function which accounts for the sparseness of the measured signal in the spatial and temporal directions. This leads to the definition of a higher dimensional total variation. The method is validated using in vivo cardiac micro-CT mouse data. Additionally, we compare the results to phase-correlated reconstructions using the FDK algorithm and a total variation constrained reconstruction, where the total variation term is only defined in the spatial domain. The reconstructed datasets show strong improvements in terms of artifact reduction and low-contrast resolution compared to other methods. Thereby the temporal resolution of the reconstructed signal is not affected.