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. 10, 2021
Filed:
Nov. 30, 2018
Canon Medical Systems Corporation, Otawara, JP;
The University of Central Florida Research Foundation, Inc., Orlando, FL (US);
Alexander Katsevich, Oviedo, FL (US);
Zhou Yu, Wilmette, IL (US);
Daxin Shi, Buffalo Grove, IL (US);
CANON MEDICAL SYSTEMS CORPORATION, Otawara, JP;
THE UNIVERSITY OF CENTRAL FLORIDA RESEARCH FOUNDATION, Inc., Orlando, FL (US);
Abstract
A method and apparatus is provided to reconstruct a computed tomography image using iterative reconstruction (IR) that is accelerated using various combinations of ordered subsets, conjugate gradient, preconditioning, resetting/restarting, and/or gradient approximation techniques. For example, when restarting criteria are satisfied the IR algorithm can be reset by setting conjugate-gradient parameters to initial values and/or by changing the number of ordered subsets. The IR algorithm can be accelerated by approximately calculating the gradients, by using a diagonal or Fourier preconditioner, and by selectively updating the preconditioner based on the regularization function. The update direction and step size can be calculated using the preconditioner and a surrogate function, which is not necessarily separable.