公开(公告)号：US12073538B2

公开(公告)日：2024-08-27

申请号：US17225672

申请日：2021-04-08

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Chung Chan ,  Li Yang ,  Wenyuan Qi ,  Evren Asma ,  Jeffrey Kolthammer ,  Yi Qiang

IPC: G06T5/70 ,  G06N3/084 ,  G06T7/00

CPC classification number: G06T5/70 ,  G06N3/084 ,  G06T7/0012 ,  G06T2207/20081 ,  G06T2207/20084

Abstract: Existing, low quality images can be restored using reconstruction or a combination of post-reconstruction techniques to generate a real patient phantom. The real patient phantom (RPP) can then be simulated in Monte Carlo simulations of a higher performance system and a lower performance system. Alternatively, the RPP can be simulated in the higher performance system, and a real scan can be performed by an existing, lower performance system. The higher performance system can be differentiated from the lower performance system in a variety of ways, including a higher resolution time of flight measurement capability, a greater sensitivity, smaller detector crystals, or less scattering. A neural network can be trained using the images produce by the higher performance system as the target, and the images produced by the lower performance system as the input. After training, the trained neural network can be used to output input images taken in a lower performance system with higher performance system characteristics.

公开(公告)号：US11982779B2

公开(公告)日：2024-05-14

申请号：US17230372

申请日：2021-04-14

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Wenyuan Qi ,  Yi Qiang ,  Peng Peng ,  Evren Asma ,  Jeffrey Kolthammer

IPC: G01T1/29 ,  G01T1/202

CPC classification number: G01T1/2907 ,  G01T1/202 ,  G01T1/2985

Abstract: A guided pairing method includes generating a singles list by detecting a plurality of singles at a plurality of detector elements in a detector array, the plurality of singles falling within a plurality of detection windows; for each detection window of the plurality of detection windows in the singles list having exactly two singles of the plurality of singles, determining the line of responses (LORs) for each of the two singles of the plurality of singles; for each detection window of the plurality of detection windows in the singles list having more than two singles of the plurality of singles, determining all coincidences possible based on the more than two singles; generating a weight for said each coincidence of the coincidences based on the determined LORs for said each of the two singles of the plurality of singles; and pairing the more than two singles based on the generated weight for said each coincidence of the coincidences.

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.

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.

公开(公告)号：US11759162B2

公开(公告)日：2023-09-19

申请号：US17345716

申请日：2021-06-11

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Wenyuan Qi ,  Yujie Lu ,  Ryo Okuda ,  Evren Asma ,  Manabu Teshigawara ,  Jeffrey Kolthammer

IPC: A61B6/00 ,  A61B6/03

CPC classification number: A61B6/5282 ,  A61B6/032 ,  A61B6/037 ,  A61B6/5205

Abstract: The present disclosure is related to removing scatter from a SPECT scan by utilizing a radiative transfer equation (RTE) method. An attenuation map and emission map are acquired for generating scatter sources maps and scatter on detectors using the RTE method. The estimated scatter on detectors can be removed to produce an image of a SPECT scan with less scatter. Both first-order and multiple-order scatter can be estimated and removed. Additionally, scatter caused by multiple tracers can be determined and removed.

公开(公告)号：US11276209B2

公开(公告)日：2022-03-15

申请号：US16860425

申请日：2020-04-28

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Wenyuan Qi ,  Yujie Lu ,  Evren Asma ,  Yi Qiang ,  Jeffrey Kolthammer ,  Zhou Yu

IPC: G06T11/00 ,  A61B6/03 ,  A61B6/00 ,  G06T7/00

Abstract: The present disclosure relates to an apparatus for estimating scatter in positron emission tomography, comprising processing circuitry configured to acquire an emission map and an attenuation map, each representing an initial image reconstruction of a positron emission tomography scan, calculate, using a radiative transfer equation (RTE) method, a scatter source map of a subject of the positron emission tomography scan based on the emission map and the attenuation map, estimate, using the RTE method and based on the emission map, the attenuation map, and the scatter source map, scatter, and perform an iterative image reconstruction of the positron emission tomography scan based on the estimated scatter and raw data from the positron emission tomography scan of the subject.

公开(公告)号：US11096633B1

公开(公告)日：2021-08-24

申请号：US16885038

申请日：2020-05-27

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Wenyuan Qi ,  Yi Qiang ,  Evren Asma ,  Jeffrey Kolthammer

IPC: A61B6/03 ,  A61B6/00 ,  G01T1/29

Abstract: A positron emission tomography scanner includes a plurality of gamma-ray detector rings that form a bore through which an imaging subject is translated, each of the plurality of gamma-ray detector rings being in a first axial position, and processing circuitry configured to receive attenuation data associated with a plurality of transaxial slices of the imaging subject, determine a second axial position of each of the plurality of gamma-ray detector rings based on the received attenuation data, and adjust a position of each of the plurality of gamma-ray detector rings from the first axial position to the second axial position. The processing circuitry may further be configured to calculate an attenuation metric based on the received attenuation data, and determine the second axial position such that the attenuation metric calculated for each pair of adjacent gamma-ray detector rings is equal.