Research on cone-beam ray three dimensional large field of view industrial CT imaging method

Cone-beam three-dimensional industrial computed tomography(3D-ICT) with circular orbit scan mode based on FDK reconstruction algorithm is more favorable than other types. It is mathematically simpler and more feasible. However, limited by the length of detector, this technique has a small field of view. In order to execute the 3D-ICT inspection of large objects an imaging method called large field of view 3D-ICT shifting the rotation gantry was discussed. Its filter back-projection reconstruction algorithm based on FKD principle was deduced. The results of computer simulation and experiments prove the validity of this method. Analysis shows that the scan field of view along the horizon can be improved no less than 80% compared with cone-beam 3D-CT based on FDK and circular orbit scan mode.