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:
Jun. 17, 1997
Filed:
Jan. 19, 1996
Hiroyuki Kawai, Tokyo, JP;
Kensuke Sekihara, Musashimurayama, JP;
Hitachi Medical Corporation, Tokyo, JP;
Abstract
A method for X-ray computed tomography includes a process for rotating around an object an X-ray source for applying a cone-beam X ray and a scanner having a two-dimensional X-ray detector mounted thereon for deriving projection data and a process for preparing a geometric distortion correction table for correcting an image geometric distortion of the two-dimensional X-ray detector for the projection data, for reconstructing a distribution of X-ray attenuation coefficients of the object from said corrected projection data. The method further includes a process for calculating a function for evaluating the correction table, a process for comparing the calculated value with a threshold value, a process for correcting the correction table through the interpolation based on the compared result, a process for correcting an image geometric distortion of the projection data by using the corrected table, a process for detecting a location of a view field boundary of the detector from the distortion-corrected projection data, and a process for generating the projection data of a predetermined width from the detected location of the view field boundary through the effect of the extrapolation. The method operates to reconstruct a distribution of X-ray attenuation coefficients of the object from the extrapolated projection data.