Exact 3D cone-beam reconstruction from two short-scans using a C-arm imaging system

In this paper we present a source path for the purpose of exact cone-beam reconstruction using a C-arm X-ray imaging system. The proposed path consists of two intersecting segments, each of which is a short-scan. Any C-arm capable of a short-scan sweep can thus be used to obtain data on our proposed source path as well, since it only requires an additional sweep on a tilted plane. This tilt can be achieved by either using the propeller axis of mobile C-arms, or the vertical axis of ceiling mounted C-arms. While the individual segments are only capable of exact reconstruction in their mid-plane, we show that the combined path is capable of exact reconstruction within an entire volumetric region. In fact, we show that the largest sphere that can be captured in the field of view of the C-arm can be exactly reconstructed if the tilt between the planes is at least equal to the cone-angle of the system. For the purpose of cone-beam inversion we use a generalized cone-beam filtered backprojection algorithm (CB-FBP). The exactness of this method relies on the design of a set of redundancy weights, which we explicitly evaluate for the proposed dual short-scan source path.

在本文中，我们提出了一种源路径，用于使用C型臂X射线成像系统进行精确的锥束重建。所提出的路径由两个相交的线段组成，每个线段都是一次短扫描。因此，任何能够进行短扫描的C型臂也可用于获取我们所提出的源路径上的数据，因为它只需要在一个倾斜平面上进行额外的扫描。这种倾斜可以通过使用移动C型臂的螺旋桨轴或天花板安装式C型臂的垂直轴来实现。虽然各个线段仅能在其中心平面进行精确重建，但我们表明组合路径能够在整个体积区域内进行精确重建。实际上，我们表明如果平面之间的倾斜度至少等于系统的锥角，则C型臂视野内可捕获的最大球体能够被精确重建。为了进行锥束反演，我们使用一种广义的锥束滤波反投影算法（CB - FBP）。这种方法的精确性依赖于一组冗余权重的设计，我们针对所提出的双短扫描源路径明确地评估了这些权重。