True 3D cone-beam imaging method and apparatus

摘要

A three-dimensional image of an object scanned with a plurality of cone-beam projections from a number of source positions is reconstructed using a method wherein intermediate transform functions are obtained from two-dimensional images of radiation attenuation in the scanned object. The intermediate transform functions are then filtered over a set of parallel planes using a moving-frame technique. The second-order radial derivative of the Radon transform can then be backprojected to generate an intermediate, locally-reconstructed, three-dimensional image. After repetition of this process, the plurality of intermediate, locally reconstructed, three-dimensional images are summed to obtain an ultimate, reconstructed, three-dimensional image of the object. In particular embodiments, the source and detector are displaced along helical paths and radiation scans of the object are taken at multiple positions along the paths.