US 11,653,892 B2
Counting response and beam hardening calibration method for a full size photon-counting CT system
Xiaohui Zhan, Vernon Hills, IL (US); Xiaofeng Niu, Vernon Hills, IL (US); and Ilmar Hein, Vernon Hills, IL (US)
Assigned to CANON MEDICAL SYSTEMS CORPORATION, Otawara (JP)
Filed by CANON MEDICAL SYSTEMS CORPORATION, Otawara (JP)
Filed on Jan. 22, 2021, as Appl. No. 17/156,089.
Prior Publication US 2022/0233162 A1, Jul. 28, 2022
Int. Cl. A61B 6/00 (2006.01); A61B 6/03 (2006.01); G06T 7/10 (2017.01); G01T 7/00 (2006.01); G06T 11/00 (2006.01)
CPC A61B 6/585 (2013.01) [A61B 6/032 (2013.01); A61B 6/4035 (2013.01); A61B 6/4241 (2013.01); A61B 6/4447 (2013.01); A61B 6/583 (2013.01); G01T 7/005 (2013.01); G06T 7/10 (2017.01); G06T 11/005 (2013.01); G06T 2207/10081 (2013.01); G06T 2207/30004 (2013.01); G06T 2211/40 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method for calibrating a counting response of a photon counting detector (PCD) and for correcting for beam hardening, in a photon counting computed tomography (CT) system, the method comprising:
performing a plurality of low flux scans comprising an air scan and scans using a plurality of slabs of different materials, at an initial current intensity and at plural tube voltage settings of an X-ray tube, for each scan, to obtain counts for each energy bin;
estimating calibration parameters based on the counts, the calibration parameters being parameters for estimating the counting response of the PCD;
calculating beam hardening correction terms in object/patient scans based on the estimated calibration parameters; and
generating a corrected counting image using the beam hardening correction terms.