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:
Feb. 01, 2011
Filed:
Mar. 11, 2008
LI Zhang, Beijing, CN;
Zhiqiang Chen, Beijing, CN;
Gnowei Zhang, Beijing, CN;
Jianping Cheng, Beijing, CN;
Yuanjing LI, Beijing, CN;
Yinong Liu, Beijing, CN;
Yuxiang Xing, Beijing, CN;
Ziran Zhao, Beijing, CN;
Yongshun Xiao, Beijing, CN;
Li Zhang, Beijing, CN;
Zhiqiang Chen, Beijing, CN;
Gnowei Zhang, Beijing, CN;
Jianping Cheng, Beijing, CN;
Yuanjing Li, Beijing, CN;
Yinong Liu, Beijing, CN;
Yuxiang Xing, Beijing, CN;
Ziran Zhao, Beijing, CN;
Yongshun Xiao, Beijing, CN;
Tsinghua University, , CN;
Nuctech Company Limited, , CN;
Abstract
A method for calibrating a dual-energy CT system and an image reconstruction method are disclosed to calculate images of atomic number and density of a scanned object as well as its attenuation coefficient images at any energy level. The present invention removes the effect from a cupping artifact due to X-ray beam hardening. The method for calibrating a dual-energy CT system is provided comprising steps of selecting at least two different materials, detecting penetrative rays from dual-energy rays penetrating said at least two different materials under different combinations of thickness to acquire projection values, and creating a lookup table in a form of correspondence between said different combinations of thickness and said projection values. The image reconstruction method is provided comprising steps of scanning an object with dual-energy rays to acquire dual-energy projection values, calculating projection values of base material coefficients corresponding to said dual-energy projection values based on a pre-created lookup table, and reconstructing an image of base material coefficient distribution based on said projection values of base material coefficients. In this way, images of atomic number and density of an object as well as its attenuation coefficient images can be calculated from the images of the distribution of base material coefficients. Compared with the prior art technique, the method proposed in the present invention has advantages of simple calibration procedure, high calculation precision and invulnerability to X-ray beam hardening.