RECONSTRUCTION IN CT SCANNERS USING DIVERGENT BEAMS WITH FLATNESS CORRECTION FOR REORDERED DATA

Divergent X-ray beams of a computerized tomographic system are used for reconstruction with parallel reconstruction algorithms by determining "sets" of the divergent X-ray beams after passage through the patient at a number of angularly spaced positions within the angle subtended by the divergent beams. The determined sets are reordered, filtered and rebinned to obtain laterally spaced parallel filtered data that are backprojected to form the tomographic image. Corrections are made on the detected divergent beams to prevent "cupping" and to assure that the image has correct CT numbers.