医学图像配准，2D_3D医学图像配准论文-In 2D-3D Medical Image Registration (MIR), preoperative 3D CT images are registered

with intraoperative 2D X-rays images obtained by fluoroscopy or Electronic Portal Imag-

ing Devices (EPID). 2D-3D MIR is established by computing Digitally Reconstructed Ra-

diograph (DRR) images rendered from the volumetric data and is useful in many med-

ical procedures where surgical planning is undertaken using volumetric data prior to

treatment, such as in radiation therapy treatment and image guide surgery. The conven-

tional approach used to render DRR images is a computationally expensive process and

forms a bottleneck in 2D-3D MIR. This paper evaluates the registration performance of

a 2D-3D MIR system which attempts to improve the rendering performance by reduc-

ing the number of intersections between the rays cast and internal spaces within the CT

volume by using an Octree compression. An Octree compressed CT volume comprises

fewer internal spaces, each containing voxels which shar