Mallinckrodt Inst. of Radiol., Washington Univ., St. Louis, MO.
IEEE Trans Med Imaging. 1993;12(3):486-96. doi: 10.1109/42.241876.
Considering the characteristics of the X-ray microscope system being developed at SUNY at Buffalo and the limitations of available cone-beam reconstruction algorithms, a general cone-beam reconstruction algorithm and several special versions of it are proposed and validated by simulation. The cone-beam algorithm allows various scanning loci, handles reconstruction of rod-shaped specimens which are common in practice, and facilitates near real-time reconstruction by providing the same computational efficiency and parallelism as L.A. Feldkamp et al.'s (1984) algorithm. Although the present cone-beam algorithm is not exact, it consistently gives satisfactory reconstructed images. Furthermore, it has several nice properties if the scanning locus meets some conditions. First, reconstruction within a midplane is exact using a planar scanning locus. Second, the vertical integral of a reconstructed image is equal to that of the actual image. Third, reconstruction is exact if an actual image is independent of rotation axis coordinate z. Also, the general algorithm can uniformize and reduce z-axis artifacts, if a helix-like scanning locus is used.
考虑到布法罗纽约州立大学正在开发的 X 射线显微镜系统的特点和现有锥束重建算法的局限性，提出并通过模拟验证了一种通用的锥束重建算法及其几个特殊版本。该锥束算法允许各种扫描轨迹，处理在实际中常见的杆状标本的重建，并通过提供与 L.A. Feldkamp 等人的算法（1984 年）相同的计算效率和并行性来促进近实时重建。尽管目前的锥束算法并不精确，但它始终能给出令人满意的重建图像。此外，如果扫描轨迹满足某些条件，它具有几个很好的性质。首先，使用平面扫描轨迹，在中平面内的重建是精确的。其次，重建图像的垂直积分等于实际图像的积分。第三，如果实际图像与旋转轴坐标 z 无关，则重建是精确的。此外，如果使用类似螺旋的扫描轨迹，通用算法可以均匀化并减少 z 轴伪影。
