US Patent 10163207 Fluoroscopic pose estimation

Methods and systems for registering three-dimensional (3D) CT image data with two-dimensional (2D) fluoroscopic image data using a plurality of markers are disclosed. In the methods and systems, a lateral angle and a cranial angle are searched for and a roll angle is computed. 3D translation coordinates are also computed. The calculated roll angle and 3D translation coordinates are computed for a predetermined number of times successively. After performing the calculations, the 3D CT image data is overlaid on the 2D fluoroscopic image data based on the lateral angle, the cranial angle, the roll angle, and the 3D translation coordinates.