A FIDELITY CHECK OF A PRACTICAL CONE-BEAM TOMOGRAPHY ALGORITHM

Cone-beam tomography is currently being developed for commercial appli cations wherever two-dimensional X-ray tomography is being used. One p opular method for reconstructing a three dimensional image of an objec t (from cone-beam data), is the Feldkamp-Davis-Kress (FDK) algorithm, and it is an extension of the well known convolution and backprojectio n (CBP) method used in the usual two dimensional cases. This study inv estigates the fidelity of approximations involved in the FDK algorithm . Test data is obtained by the cone-beam X-ray scanner developed at th e Institute of Cancer Research (Surrey, England). The error formula fo r the CBP filters plays a key role in this work.