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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：US20240210575A1
公开(公告)日：2024-06-27
申请号：US18086966
申请日：2022-12-22
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Yi QIANG , Kent C. BURR
CPC classification number: G01T1/2006 , G01T1/15 , G01T1/1644 , H03K3/021
Abstract: An apparatus and method are provided to correct for time-walk errors during photon detections (e.g., detecting gamma rays). A time-walk correction is determined using measurements of energy (or charge) that apply different time windows, enabling corrections accounting for variations in the ratio between fast and slow components in the detected pulse. For example, one time window can be used to integrate the leading end of the pulse, thereby predominantly measuring the fast component, while a second window is used to integrate a trailing end of the pulse to predominantly measure the slow component. Alternatively or additionally, low-pass and high-pass filters may select the slow and fast components, respectively. The time-walk correction is a function of multiple measurements representing different components (e.g., fast and slow) of the pulse shape.
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4.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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5.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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Patent Agency Ranking
公开(公告)号：US20240122558A1
公开(公告)日：2024-04-18
申请号：US17963737
申请日：2022-10-11
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Wenyuan QI , Kent C. BURR , Yi QIANG , Evren ASMA , Jeffrey KOLTHAMMER
CPC classification number: A61B6/037 , A61B6/4258 , A61B6/481
Abstract: A PET scanner includes gamma-ray detector rings that form a bore through which an imaging subject is translated, a length of the bore defining an axial length of the PET scanner, the gamma-ray detector rings being movable along the axial length, the gamma-ray detector rings including gamma-ray detector modules therein, and processing circuitry configured to receive PET data associated with a plurality of transaxial slices of the imaging subject, the PET data including a first set of spatial information and timing information corresponding to a first data acquisition period for the gamma-ray detector modules in a first axial position and a second set of spatial information and timing information corresponding to a second data acquisition period for the gamma-ray detector modules in a second axial position, and reconstruct a PET image based on the first set of spatial and timing information and the second set of spatial and timing information.
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7.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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公开(公告)号：US20240230934A1
公开(公告)日：2024-07-11
申请号：US18152856
申请日：2023-01-11
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Kent C. BURR , Nikolay MARKOV , Yi QIANG
Abstract: An apparatus for calibrating a detector, including acquiring an energy spectrum obtained from a scan using an X-ray tube as a source of radiation, estimating calibration parameters, such as a gain and an offset, for each of several channels of the detector by applying the acquired first energy spectrum to inputs of a trained neural network that outputs the calibration parameters, and calibrating each of the plurality of channels using the estimation parameters. The neural network is trained to produce target output calibration parameters, using two or more measurements selected from isotope peak positions, K-edge absorption features, or K-edge emission peaks.
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公开(公告)号：US20220397688A1
公开(公告)日：2022-12-15
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
IPC: G01T1/29
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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公开(公告)号：US20220252746A1
公开(公告)日：2022-08-11
申请号：US17168852
申请日：2021-02-05
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Kent C. BURR , Yi QIANG , Xiaoli LI
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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