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公开(公告)号：US20240050058A1
公开(公告)日：2024-02-15
申请号：US17886716
申请日：2022-08-12
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Xiaoli LI , Yi QIANG , Wenyuan QI
CPC classification number: A61B6/5282 , A61B6/037 , G06T11/005 , G06T2211/424
Abstract: A method is provided for determining a scatter fraction for a radiation diagnosis apparatus. The method includes acquiring an energy spectrum from list mode data obtained from a scan performed using the radiation diagnosis apparatus; determining, from the acquired list mode data, a first number of events occurring in a first energy window spanning a first energy range; determining, from the acquired list mode data, a second number of events occurring in a second window, the second energy window spanning a second energy range different from the first energy range; calculating a singles scatter fraction based on the determined first number of events and the determined second number of events; and reconstructing an image based on the acquired list mode data and the calculated singles scatter fraction.
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2.发明申请公开(公告)号：US20200379133A1
公开(公告)日：2020-12-03
申请号：US16738828
申请日：2020-01-09
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Kent C. BURR , Xiaoli LI
Abstract: A method and apparatus are provided for positron emission imaging to calibrate energy measurements of a pixilated gamma-ray detector using energy calibration based on a calibration with a distribution energy signature (i.e., having more spectral features than just a single full-energy peak). The energy calibration can be performed using a deep learning (DL) network or a physics-based model. Using the DL network, a calibration spectrum is applied to either generate the measured-signal values of known energy values (e.g., spectral peaks for spectra of various radioactive isotopes) or the parameters of an energy-calibration function/model.
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3.发明申请公开(公告)号：US20200249369A1
公开(公告)日：2020-08-06
申请号：US16269380
申请日：2019-02-06
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 energy measurements of a pixilated gamma-ray detector using energy sharing events between channels of the detector. Due to conservation of energy, when the energy of a single gamma ray shared among multiple channels, the sum of measured energies across the respective channel must equal the original energy of the incident gamma ray. Further, the fractions of the original energy distributed to the respective channels can span the entire range of zero to the original energy. Thus, a single gamma-ray source (e.g., cesium isotope 137) can be used to continuously calibrate the nonlinear energy response of the detector over an entire range of interest.
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公开(公告)号：US20240125951A1
公开(公告)日：2024-04-18
申请号：US17960689
申请日：2022-10-05
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Xiaoli LI , Yi QIANG , Jeffrey KOLTHAMMER , Masaki MIYAHARA
CPC classification number: G01T1/2985 , A61B6/037 , G06T11/003
Abstract: A positron emission tomography (PET) scanner is provided having a plurality of detector subsystems, including processing circuitry to determine, for each detector subsystem of the plurality of detector subsystems, a singles count loss correction factor of the detector subsystem; determine, for each detector subsystem pair of a plurality of pairs of the detector subsystems, a coincidence count loss correction factor for the detector subsystem pair; calculate a scanner coincidence count loss correction factor for the PET scanner based on the coincidence count loss correction factors determined for the plurality of pairs of the detector subsystems; and reconstruct an image based on the calculated scanner count loss correction factor and scan data acquired from a scan of a patient performed using the PET scanner.
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5.发明公开公开(公告)号：US20230236328A1
公开(公告)日：2023-07-27
申请号：US17581005
申请日：2022-01-21
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Peng PENG , Yi QIANG , Xiaoli LI , Kent C. BURR , Manabu TESHIGAWARA
CPC classification number: G01T1/1642 , G01T1/2985 , A61B6/4258 , A61B6/037 , G01T1/1644 , G01T1/2018
Abstract: A method and apparatuses for a radiation detector apparatus, comprising a scintillator array comprising a plurality of scintillator crystals. The plurality of scintillator crystals includes a first scintillator crystal and a second scintillator crystal adjacent to the first scintillator crystal within the scintillator array. A photosensor array comprising a plurality of photosensors including a first photosensor configured to detect photons from the first scintillator crystal. A first separator positioned between the first scintillator crystal and the second scintillator crystal. First separator optically separates the first scintillator crystal and the second scintillator crystal such that the first photosensor detects photons from the first scintillator crystal and not from the second scintillator crystal.
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Patent Agency Ranking
公开(公告)号：US20220343566A1
公开(公告)日：2022-10-27
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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公开(公告)号：US20220113437A1
公开(公告)日：2022-04-14
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
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：US20210247530A1
公开(公告)日：2021-08-12
申请号：US16788741
申请日：2020-02-12
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Xiaoli LI , Yi QIANG , Kent C. BURR
Abstract: A method and apparatus are provided for nonlinear energy correction of a gamma-ray detector using a calibration spectrum acquired from the background radiation of lutetium isotope 176 (Lu-176) present in scintillators in the gamma-ray detector. Further, by periodically acquiring Lu-176 spectra using the background radiation from the scintillators, the nonlinear energy correction can be monitored to detect when changes in the gamma-ray detector cause the detector to go out of calibration, and then use a newly acquired Lu-176 spectrum to update the calibration of the nonlinear energy correction as needed. The detector calibration is performed by comparing a reference histogram to a calibration histogram generated using the nonlinear energy correction, and adjusting the parameters of the nonlinear energy correction until the two histograms match. Alternatively, the detector calibration is performed by comparing reference and calibration values for specific spectral features, rather than for the whole Lu-176 spectrum.
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公开(公告)号：US20210199823A1
公开(公告)日：2021-07-01
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：US20240037814A1
公开(公告)日：2024-02-01
申请号：US17878413
申请日：2022-08-01
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Chung CHAN , Li YANG , Xiaoli LI , Wenyuan QI , Evren ASMA , Jeffrey KOLTHAMMER
IPC: G06T11/00
CPC classification number: G06T11/005 , G06T2211/412
Abstract: A dynamic frame reconstruction apparatus and method for medical image processing is disclosed which reduces the computationally expensive reconstruction of images but which retains the accuracy of the image reconstruction. A convolutional neural network is used to cluster the dynamic data into groups of frames, each group sharing similar radiotracer distribution. In one embodiment, groups of frames that have similar reconstruction parameters are determined, and scatter and random estimations are computed once and shared among each of the frames in the same frame group.
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