Click on image to view larger version.
Figure A1. Reconstruction geometry of cone-beam CT. An X-ray source and a 2D detector rotate around the z-axis. The volume that can be reconstructed with the Feldkamp algorithm is shown by the shaded region and is a double conical region within a cylinder of radius Rmax, which is determined by the detector size in the x-direction and shows the maximum field of view in the transverse plane. R and H show diameter and height, respectively, of a cylindrical reconstructed volume as it varied with an object. N x T show the nominal beam width where N is the number of slice and T is the slice collimation.
