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公开(公告)号:US11224399B2
公开(公告)日:2022-01-18
申请号:US16510594
申请日:2019-07-12
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor: Tzu-Cheng Lee , Jian Zhou , Zhou Yu
Abstract: A method and apparatus is provided that uses a deep learning (DL) network to correct projection images acquired using an X-ray source with a large focal spot size. The DL network is trained using a training dataset that includes input data and target data. The input data includes large-focal-spot-size X-ray projection data, and the output data includes small-focal-spot-size X-ray projection data (i.e., smaller than the focal spot of the input data). Thus, the DL network is trained to improve the resolution of projection data acquired using a large focal spot size, and obtain a resolution similar to what is achieved using a small focal spot size. Further, the DL network is can be trained to additional correct other aspects of the projection data (e.g., denoising the projection data).
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2.
公开(公告)号:US20200234471A1
公开(公告)日:2020-07-23
申请号:US16252392
申请日:2019-01-18
Applicant: Canon Medical Systems Corporation
Inventor: Yujie Lu , Zhou Yu , Jian Zhou , Tzu-Cheng Lee , Richard Thompson
Abstract: A method and apparatus are provided for using a neural network to estimate scatter in X-ray projection images and then correct for the X-ray scatter. For example, the neural network is a three-dimensional convolutional neural network 3D-CNN to which are applied projection images, at a given view, for respective energy bins and/or material components. The projection images can be obtained by material decomposing spectral projection data, or by segmenting a reconstructed CT image into material-component images, which are then forward projected to generate energy-resolved material-component projections. The result generated by the 3D-CNN is an estimated scatter flux. To train the 3D-CNN, the target scatter flux in the training data can be simulated using a radiative transfer equation method.
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公开(公告)号:US12243127B2
公开(公告)日:2025-03-04
申请号:US17699008
申请日:2022-03-18
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor: Tzu-Cheng Lee , Jian Zhou , Liang Cai , Zhou Yu , Masakazu Matsuura , Takuya Nemoto , Hiroki Taguchi
Abstract: A medical image processing method includes obtaining a first set of projection data by performing, with a first CT apparatus including a first detector with a first pixel size, a first CT scan of an object in a first imaging region of the first detector; obtaining a first CT image with a first resolution by reconstructing the first set of projection data; obtaining a processed CT image with a resolution higher than the first resolution by applying a machine-learning model for resolution enhancement to the first CT image; and displaying the processed CT image or outputting the processed CT image for analysis. The machine-learning model is obtained by training using a second CT image based on a second set of projection data acquired by a second CT scan of the object in a second imaging region with a second CT apparatus including a second detector with a second pixel size.
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公开(公告)号:US11547378B2
公开(公告)日:2023-01-10
申请号:US16509369
申请日:2019-07-11
Applicant: Canon Medical Systems Corporation
Inventor: Ilmar Hein , Zhou Yu , Tzu-Cheng Lee
Abstract: A method and apparatus is provided that uses a deep learning (DL) network together with a multi-resolution detector to perform X-ray projection imaging to provide improved resolution similar to a single-resolution detector but at lower cost and less demand on the communication bandwidth between the rotating and stationary parts of an X-ray gantry. The DL network is trained using a training dataset that includes input data and target data. The input data includes projection data acquired using a multi-resolution detector, and the target data includes projection data acquired using a single-resolution, high-resolution detector. Thus, the DL network is trained to improve the resolution of projection data acquired using a multi-resolution detector. Further, the DL network is can be trained to additional correct other aspects of the projection data (e.g., noise and artifacts).
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公开(公告)号:US20220327750A1
公开(公告)日:2022-10-13
申请号:US17699008
申请日:2022-03-18
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor: Tzu-Cheng Lee , Jian Zhou , Liang Cai , Zhou Yu , Masakazu Matsuura , Takuya Nemoto , Hiroki Taguchi
Abstract: A medical image processing method includes obtaining a first set of projection data by performing, with a first CT apparatus including a first detector with a first pixel size, a first CT scan of an object in a first imaging region of the first detector; obtaining a first CT image with a first resolution by reconstructing the first set of projection data; obtaining a processed CT image with a resolution higher than the first resolution by applying a machine-learning model for resolution enhancement to the first CT image; and displaying the processed CT image or outputting the processed CT image for analysis. The machine-learning model is obtained by training using a second CT image based on a second set of projection data acquired by a second CT scan of the object in a second imaging region with a second CT apparatus including a second detector with a second pixel size.
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6.
公开(公告)号:US12008689B2
公开(公告)日:2024-06-11
申请号:US17542245
申请日:2021-12-03
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor: Yujie Lu , Tzu-Cheng Lee , Liang Cai , Jian Zhou , Zhou Yu
CPC classification number: G06T11/005 , G06N3/08 , G16H30/40 , G06T2211/40
Abstract: Devices, systems, and methods obtain first radiographic-image data reconstructed based on a set of projection data acquired in a radiographic scan; apply one or more trained machine-learning models to the set of projection data and the first radiographic-image data to obtain a set of parameters for a scatter kernel; input the set of parameters and the set of projection data into the scatter kernel to obtain scatter-distribution data; and perform scatter correction on the set of projection data using the scatter-distribution data, to obtain a set of corrected projection data.
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7.
公开(公告)号:US20230177745A1
公开(公告)日:2023-06-08
申请号:US17542245
申请日:2021-12-03
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor: Yujie Lu , Tzu-Cheng Lee , Liang Cai , Jian Zhou , Zhou Yu
CPC classification number: G06T11/005 , G16H30/40 , G06N3/08 , G06T2211/40
Abstract: Devices, systems, and methods obtain first radiographic-image data reconstructed based on a set of projection data acquired in a radiographic scan; apply one or more trained machine-learning models to the set of projection data and the first radiographic-image data to obtain a set of parameters for a scatter kernel; input the set of parameters and the set of projection data into the scatter kernel to obtain scatter-distribution data; and perform scatter correction on the set of projection data using the scatter-distribution data, to obtain a set of corrected projection data.
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公开(公告)号:US11176428B2
公开(公告)日:2021-11-16
申请号:US16372206
申请日:2019-04-01
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor: Tzu-Cheng Lee , Jian Zhou , Zhou Yu
Abstract: A method and apparatus is provided to reduce the noise in medical imaging by training a deep learning (DL) network to select the optimal parameters for a convolution kernel of an adaptive filter that is applied in the data domain. For example, in X-ray computed tomography (CT) the adaptive filter applies smoothing to a sinogram, and the optimal amount of the smoothing and orientation of the kernel (e.g., a bivariate Gaussian) can be determined on a pixel-by-pixel basis by applying a noisy sinogram to the DL network, which outputs the parameters of the filter (e.g., the orientation and variances of the Gaussian kernel). The DL network is trained using a training data set including target data (e.g., the gold standard) and input data. The input data can be sinograms generated by a low-dose CT scan, and the target data generated by a high-dose CT scan.
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公开(公告)号:US10937206B2
公开(公告)日:2021-03-02
申请号:US16252392
申请日:2019-01-18
Applicant: Canon Medical Systems Corporation
Inventor: Yujie Lu , Zhou Yu , Jian Zhou , Tzu-Cheng Lee , Richard Thompson
Abstract: A method and apparatus are provided for using a neural network to estimate scatter in X-ray projection images and then correct for the X-ray scatter. For example, the neural network is a three-dimensional convolutional neural network 3D-CNN to which are applied projection images, at a given view, for respective energy bins and/or material components. The projection images can be obtained by material decomposing spectral projection data, or by segmenting a reconstructed CT image into material-component images, which are then forward projected to generate energy-resolved material-component projections. The result generated by the 3D-CNN is an estimated scatter flux. To train the 3D-CNN, the target scatter flux in the training data can be simulated using a radiative transfer equation method.
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