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1.发明公开公开(公告)号：US20230329665A1
公开(公告)日：2023-10-19
申请号：US17720977
申请日：2022-04-14
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Xiaohui ZHAN , Xiaofeng NIU , Ruoqiao ZHANG
CPC classification number: A61B6/585 , G01T7/005 , A61B6/032 , A61B6/4241 , G06T7/0012 , G06T11/005 , G06T2207/30168 , G06T2207/10081 , G06T2207/30004
Abstract: A photon counting computed tomography (CT) method including, but not limited to, receiving a first forward model including a set of first parameters and a set of second parameters corresponding to a plurality of materials and path lengths by scanning a slab at plural tube voltages and plural tube currents of an X-ray tube; evaluating an image quality of a material decomposition image reconstructed by the set of first parameters and the set of second parameters; and updating at least one second parameters from the set of second parameters if the image quality of the material decomposition image does not satisfy a predetermined threshold, wherein the update of the at least one second parameter from the set of second parameters is achieved by updating the at least one second parameter from the set of second parameters to an energy dependent parameter from a constant value. Processing circuitry that is part of a photon counting computed tomography (CT) can implement the method.
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2.发明申请公开(公告)号：US20220233162A1
公开(公告)日：2022-07-28
申请号：US17156089
申请日：2021-01-22
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Xiaohui ZHAN , Xiaofeng NIU , Ilmar HEIN
Abstract: A method and a system for providing calibration for a polychromatic photon counting detector forward counting model. Measurements with multiple materials and known path lengths are used to calibrate the photon counting detector counting response of the forward model. The flux independent weighted bin response function is estimated using the expectation maximization method, and then used to estimate the pileup correction terms at plural tube voltage settings for each detector pixel. The beam hardening corrections are then applied to the measured projection data sinogram, and the corrected sinogram is reconstructed to the counting image at the selected single energy.
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Patent Agency Ranking
3.发明公开公开(公告)号：US20230263499A1
公开(公告)日：2023-08-24
申请号：US18306773
申请日：2023-04-25
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Xiaohui ZHAN , Xiaofeng NIU , Ilmar HEIN
CPC classification number: A61B6/585 , A61B6/4241 , A61B6/032 , A61B6/4447 , A61B6/583 , G06T7/10 , A61B6/4035 , G01T7/005 , G06T11/005 , G06T2207/30004 , G06T2211/40 , G06T2207/10081
Abstract: A method and a system for providing calibration for a polychromatic photon counting detector forward counting model. Measurements with multiple materials and known path lengths are used to calibrate the photon counting detector counting response of the forward model. The flux independent weighted bin response function is estimated using the expectation maximization method, and then used to estimate the pileup correction terms at plural tube voltage settings for each detector pixel. The beam hardening corrections are then applied to the measured projection data sinogram, and the corrected sinogram is reconstructed to the counting image at the selected single energy.
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4.发明申请公开(公告)号：US20220313203A1
公开(公告)日：2022-10-06
申请号：US17218924
申请日：2021-03-31
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Xiaohui ZHAN , Xiaofeng NIU
Abstract: A method and a system for providing calibration for a photon counting CT detector forward model for material decomposition. Various slabs of predetermined material and path lengths are placed in the photon counting CT detector and scanned using one or more stationary X-rays to obtain calibration data and parametrize the forward model.
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公开(公告)号：US20220229196A1
公开(公告)日：2022-07-21
申请号：US17153524
申请日：2021-01-20
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Xiaohui ZHAN , Xiaofeng NIU
Abstract: A method and a system for a two-step calibration method for the polychromatic semiconductor-based PCD forward counting model, to account for various pixel summing readout modes for imaging at different resolutions. The flux independent weighted bin response function is estimated using the expectation maximization method, and then used to estimate the pileup correction terms at plural tube voltage settings for each detector pixel. To correct the variation of the detector response due to different PCD sub-pixel summing schemes, the embodiments calibrate forward model parameters based on the various pixel readout modes.
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公开(公告)号：US20220296202A1
公开(公告)日：2022-09-22
申请号：US17206873
申请日：2021-03-19
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Xiaohui ZHAN , Ilmar HEIN , Xiaofeng NIU
IPC: A61B6/00
Abstract: An apparatus, system and method for calibrating an x-ray apparatus including acquiring sinogram data by scanning a symmetrical phantom using a plurality of detector channels; generating mirror-copied sinogram data by mirror-copying at least one of first sinogram data and second sinogram data of the acquired sinogram data, wherein the first sinogram data and the second sinogram data are generated by dividing the sinogram data at a center detector channel of the plurality of detector channels; outputting a first reconstructed image by reconstructing the mirror-copied sinogram data; and determining a calibration parameter based on the first reconstructed image.
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公开(公告)号：US20220128488A1
公开(公告)日：2022-04-28
申请号：US17571087
申请日：2022-01-07
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Xiaohui ZHAN , Xiaofeng NIU
IPC: G01N23/046 , A61B6/03 , A61B6/00 , G01N23/083
Abstract: A method and a system for providing calibration for a photon counting detector forward model for material decomposition. The flux independent weighted bin response function is estimated using the expectation maximization method, and then used to estimate the pileup correction terms at each tube voltage setting for each detector pixel.
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