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公开(公告)号：US11835668B2
公开(公告)日：2023-12-05
申请号：US17345823
申请日：2021-06-11
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Yi Qiang , Kent C. Burr , Peng Peng , Xiaoli Li
CPC classification number: G01T1/2985 , A61B6/037 , A61B6/5258
Abstract: A circuit for receiving signals from a photodetector array arranged to detect signals generated by a crystal includes a plurality of summing circuits having weighting circuits, the summing circuits being configured to produce outputs corresponding to a total energy of the signals, a position of the signals in a first dimension of the photodetector array, a position of the signals in a second dimension of the photodetector array, and a radius of a charge distribution of the signals.
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2.发明授权公开(公告)号：US10310098B1
公开(公告)日：2019-06-04
申请号：US16153486
申请日：2018-10-05
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Yi Qiang , Xiaoli Li , Evren Asma
Abstract: A method and apparatus are provided for positron emission imaging to correct a position at which a gamma ray was detected, when the gamma ray is scattered during detection. When Compton scattering occurs during detection of a gamma ray, the energy of the gamma ray deposited in multiple crystals in an array of detector elements. The corrected position is determined as a weighted sum of the position of the multiple crystals, each weighted by an inverse of the energy measured at the respective crystal. Further, the inverse-energy weight can be raised to a power p. A minimum energy threshold can be applied to determine the multiple crystals at which the gamma ray energy is deposited. The corrected position can be a floating position or can be rounded to a nearest crystal or to a nearest virtual sub-crystal.
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公开(公告)号：US11835669B2
公开(公告)日：2023-12-05
申请号：US17557710
申请日：2021-12-21
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Wenyuan Qi , Yi Qiang , Evren Asma , Xiaoli Li , Li Yang , Peng Peng , Jeffrey Kolthammer
IPC: G01T1/29
CPC classification number: G01T1/2985
Abstract: A method of normalizing detector elements in an imaging system is described herein. The method includes a line source that is easier to handle for a user, and decouples the normalization of the detector elements into a transaxial domain and an axial domain in order to isolate errors due to positioning of the line source. Additional simulations are performed to augment the real scanner normalization. A simulation of a simulated line source closely matching the real line source can be performed to isolate errors due to physical properties of the crystals and position of the crystals in the system, wherein the simulated detector crystals are otherwise modeled uniformly. A simulation of a simulated cylinder source can be performed to determine errors due to other effects stemming from gaps between the detector crystals.
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公开(公告)号：US11249206B2
公开(公告)日：2022-02-15
申请号：US16866993
申请日：2020-05-05
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Wenyuan Qi , Yi Qiang , Evren Asma , Xiaoli Li , Li Yang , Peng Peng , Jeffrey Kolthammer
IPC: G01T1/29
Abstract: A method of normalizing detector elements in an imaging system is described herein. The method includes a line source that is easier to handle for a user, and decouples the normalization of the detector elements into a transaxial domain and an axial domain in order to isolate errors due to positioning of the line source. Additional simulations are performed to augment the real scanner normalization. A simulation of a simulated line source closely matching the real line source can be performed to isolate errors due to physical properties of the crystals and position of the crystals in the system, wherein the simulated detector crystals are otherwise modeled uniformly. A simulation of a simulated cylinder source can be performed to determine errors due to other effects stemming from gaps between the detector crystals.
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公开(公告)号：US20200183025A1
公开(公告)日：2020-06-11
申请号：US16212326
申请日：2018-12-06
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Yi Qiang , Xiaoli Li , Kent C. Burr
Abstract: A method and apparatus are provided for positron emission imaging to calibrate timing of a pixelated gamma detector using multi-channel events. The apparatus can include processing circuitry configured to obtain calibration data representing a time and a position at which gamma rays are detected at a plurality of detector elements, and determine which gamma-ray detections of the calibration data correspond to multi-channel detections in which energy of a respective gamma ray is shared and detected by two or more of the plurality of detector elements. Additionally, the processing circuitry can be configured to determine a timing calibration of the plurality of detector elements by optimizing an objective representing agreement between time data of the multi-channel detections in the calibration data and the timing calibration.
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Patent Agency Ranking
公开(公告)号：US12193858B2
公开(公告)日：2025-01-14
申请号：US17870346
申请日：2022-07-21
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Yi Qiang , Xiaoli Li , Wenyuan Qi
Abstract: A method is provided for count loss correction based on detector dead time in a radiation diagnosis apparatus. The method includes acquiring scan data from a scan of a patient performed using the radiation diagnosis apparatus; determining, from the acquired scan data, a first count rate occurring in a first energy window spanning a first energy range; determining, from the acquired scan data, a second count rate occurring in a second window spanning a second energy range, the second energy range being different from the first energy range; calculating a particular count loss correction factor based on the determined first count rate and the determined second count rate; and reconstructing an image based on the acquired scan data and the calculated particular count loss correction factor.
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公开(公告)号：US12042326B2
公开(公告)日：2024-07-23
申请号：US17168852
申请日：2021-02-05
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Kent C. Burr , Yi Qiang , Xiaoli Li
CPC classification number: A61B6/58 , A61B6/037 , A61B6/4275 , G01T1/2985
Abstract: In a gamma-ray detector system, such as a PET detector, coincidence events between multiple detector elements can be caused by inter-detector scattering and/or energy escape of the multi-stage radiation background in the scintillator crystals. Because these types of coincidence events are more likely to happen between nearby elements, they can be measured, analyzed and ultimately used to identify arrangement errors of detector elements in a gamma-ray detector system.
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公开(公告)号：US11573339B2
公开(公告)日：2023-02-07
申请号：US16907972
申请日：2020-06-22
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Xiaoli Li , Yi Qiang , Kent C. Burr , Peng Peng
Abstract: A method and system for providing improved timing calibration information for use with apparatuses performing Time of Flight Positron Emission Tomography scans. Relative timing offset, including timing walk, within a set of processing units in the scanner are obtained and corrected using a stationary limited extent positron-emitting source, and timing offset between the set of processing units is calibrated using an internal radiation source, for performing calibration.
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公开(公告)号：US10962662B2
公开(公告)日：2021-03-30
申请号：US16212326
申请日：2018-12-06
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Yi Qiang , Xiaoli Li , Kent C. Burr
Abstract: A method and apparatus are provided for positron emission imaging to calibrate timing of a pixelated gamma detector using multi-channel events. The apparatus can include processing circuitry configured to obtain calibration data representing a time and a position at which gamma rays are detected at a plurality of detector elements, and determine which gamma-ray detections of the calibration data correspond to multi-channel detections in which energy of a respective gamma ray is shared and detected by two or more of the plurality of detector elements. Additionally, the processing circuitry can be configured to determine a timing calibration of the plurality of detector elements by optimizing an objective representing agreement between time data of the multi-channel detections in the calibration data and the timing calibration.
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公开(公告)号：US12299780B2
公开(公告)日：2025-05-13
申请号：US17237975
申请日：2021-04-22
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Peng Peng , Yi Qiang , Wenyuan Qi , Xiaoli Li , Li Yang
Abstract: An apparatus for reconstructing a positron emission tomography (PET) image, comprising processing circuitry configured to extract, from raw data obtained from a PET scanner, energy data and timing data associated with a plurality of annihilation events, the extracted energy data and the extracted timing data for each annihilation event corresponding to interactions between each of a pair of gamma rays generated by each annihilation event and one or more gamma ray detectors of the PET scanner, classify each annihilation event based on respective extracted energy data and respective extracted timing data, determine, for each annihilation event and based on a calculated timing resolution of the annihilation event, a width of a time-of-flight kernel, and reconstruct, by processing circuitry, the PET image based on the obtained raw data from the PET scanner and the determined width of the time-of-flight kernel associated with each annihilation event.
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