公开(公告)号：US12121388B2

公开(公告)日：2024-10-22

申请号：US17886716

申请日：2022-08-12

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Xiaoli Li ,  Yi Qiang ,  Wenyuan Qi

IPC: A61B6/00 ,  A61B6/03 ,  G06T11/00

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.

公开(公告)号：US11543545B2

公开(公告)日：2023-01-03

申请号：US16788741

申请日：2020-02-12

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Xiaoli Li ,  Yi Qiang ,  Kent C. Burr

IPC: A61B6/03 ,  G01T1/202 ,  G01T7/00 ,  G01T1/24 ,  G01T1/29 ,  G01T1/20 ,  A61B6/00

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.

公开(公告)号：US11255985B2

公开(公告)日：2022-02-22

申请号：US16738828

申请日：2020-01-09

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Kent C. Burr ,  Xiaoli Li

IPC: G01T1/29 ,  G01T1/202

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.

公开(公告)号：US12007513B2

公开(公告)日：2024-06-11

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

IPC: G01T1/20 ,  A61B6/03 ,  A61B6/42 ,  G01T1/164 ,  G01T1/29

CPC classification number: G01T1/1642 ,  A61B6/037 ,  A61B6/4258 ,  G01T1/1644 ,  G01T1/2018 ,  G01T1/2985

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.

公开(公告)号：US10782429B2

公开(公告)日：2020-09-22

申请号：US16269380

申请日：2019-02-06

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Yi Qiang ,  Xiaoli Li ,  Kent C. Burr

IPC: G01T7/00 ,  G01T1/29

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.