The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 29, 1995
Filed:
Nov. 01, 1993
Heang K Tuy, Chesterland, OH (US);
Picker International, Inc., Highland Hts., OH (US);
Abstract
An x-ray source (14) is rotated along a non-circular path (18) to irradiate a subject in an examination region (10) with a fan beam (16) of radiation. Radiation detectors convert rays of the fan beam which have traversed the examination region into electronic data which is stored as data fans in an initial data memory (22). Each data fan is zero-filled (24) and convolved by a convolver (30). Preferably, the convolver transforms each data fan into Fourier-space (32), filters each data fan in Fourier-space with a roll-off filter (36), and converts the filtered data fan back from Fourier-space (38). Each fan is weighted (42) by a 1/cos weighting function and stored in a weighted data memory (44). Rays which are redundant in a 180.degree.+ fan reconstruction are removed (46) from the convolved data fans. A pixel driven backprojector (50) backprojects each convolved and redundant ray removed data fan into an image memory (56). The backprojector weights each data value of each ray in proportion to 1/R, where R is a distance from the apex of the backprojected convolved fan to each corresponding pixel of the resultant image. A video processor (60) converts the electronic image representation stored in the image memory (56) into appropriate format for display on a video monitor (62).