General reconstruction theory for multislice X-ray computed tomography with a gantry tilt.
General reconstruction theory for multislice X-ray computed tomography with a gantry tilt.
复制标题
具有机架倾斜的多层 X 射线计算机断层扫描的一般重建理论。
DOI：
10.1109/tmi.2004.829337
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Kudo,Hiroyuki
中科院分区：
文献类型：
--
作者：
Noo,Frederic;Defrise,Michel;Kudo,Hiroyuki
本文讨论了图像重建与倾斜机架在多层螺旋CT（螺旋）数据采集。具有机架倾斜的重建问题被示出为可转化为从没有机架倾斜的多层CT数据重建虚拟对象的问题，对于该问题，存在于文献中的各种算法。通过将X射线源的倾斜螺旋轨迹变换为非倾斜螺旋的简单仿射变换，虚拟对象与真实的对象相关，并且可以使用一维插值从虚拟对象计算真实的对象。然而，由于在笛卡尔网格上重建虚拟对象直接在平行于台架的倾斜平面的切片上提供了真实的对象的无失真图像，因此可以跳过插值。该理论首先提出没有任何规格的探测器的几何形状，然后应用到弯曲的探测器的几何形状的第三代CT扫描仪与使用Katsevich的公式，例如。给出了FORBILD胸部体模的计算机模拟数据的结果来支持该理论。
This paper discusses image reconstruction with a tilted gantry in multislice computed tomography (CT) with helical (spiral) data acquisition. The reconstruction problem with gantry tilt is shown to be transformable into the problem of reconstructing a virtual object from multislice CT data with no gantry tilt, for which various algorithms exist in the literature. The virtual object is related to the real object by a simple affine transformation that transforms the tilted helical trajectory of the X-ray source into a nontilted helix, and the real object can be computed from the virtual object using one-dimensional interpolation. However, the interpolation may be skipped since the reconstruction of the virtual object on a Cartesian grid provides directly nondistorted images of the real object on slices parallel to the tilted plane of the gantry. The theory is first presented without any specification of the detector geometry, then applied to the curved detector geometry of third-generation CT scanners with the use of Katsevich's formula for example. Results from computer-simulated data of the FORBILD thorax phantom are given in support of the theory.