Reconstruction method for helical scanning computed tomography apparatus with multi-row detector array employing overlapping beams

摘要

An x-ray computed tomography system for helically scanning a patient translates the patient as projections of the patient at various beam angles are obtained. A cone beam reconstruction method, which accounts for the divergence of the rays of a fan beam of x-rays, is used to reconstruct multiple narrow slices which are combined to provide a larger slice with an improved slice profile. The conical shape of the fan beam causes some voxels to be scanned more than once for a given beam angle and this extra data is weighted and combined with its counterpart data to improve the quality of the image.