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1.发明公开公开(公告)号：US20230281760A1
公开(公告)日：2023-09-07
申请号：US18112498
申请日：2023-02-21
发明人： Atsuro Suzuki , Tomoki Amemiya , Yukio Kaneko , Toru Shirai , Keisuke Nishio
CPC分类号： G06T5/002 , A61B5/055 , G06T7/11 , G06T2207/10088 , G06T2207/20084
摘要： In an image noise reduction process using a CNN, noise can be reduced effectively irrespective of signal levels and noise levels of the image. Noise information and signal level information are calculated from an image inputted in the CNN. Using the calculated information, a normalization factor suitable for the CNN is determined, and normalization of the input image is performed. The noise information is estimated from magnitude of background noise of the input image in the case where the input image is an MRI image. The signal information can be calculated, for example, as a mean value of pixel values of a subject region with respect to an image obtained by dividing the input image by the magnitude of the background noise.
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公开(公告)号：US12089921B2
公开(公告)日：2024-09-17
申请号：US17573729
申请日：2022-01-12
发明人： Yo Taniguchi , Toru Shirai
CPC分类号： A61B5/055 , G01R33/543 , G06T7/0012 , G06T2207/10088
摘要： To provide a technique of stably obtaining quantitative parameter maps by preventing influences of artifacts caused by flow or body motion when calculated images with a plurality of parameters are generated at the same time. When a calculated image of a subject parameter or an apparatus parameter is generated by using a plurality of images obtained by performing imaging under different imaging conditions, an imaging condition under which the artifacts are easy to occur is examined in advance, and an imaging parameter set for quantitative parameter map calculation is optimized by excluding the imaging condition under which the artifact is easy to occur.
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公开(公告)号：US11940520B2
公开(公告)日：2024-03-26
申请号：US17892495
申请日：2022-08-22
发明人： Ryota Sato , Suguru Yokosawa , Toru Shirai , Kazuho Kamba , Yoshitaka Sato , Masahiro Takizawa
IPC分类号： G01R33/56 , A61B5/055 , G01R33/565 , G06T11/00
CPC分类号： G01R33/565 , A61B5/055 , G06T11/005 , G06T2207/10088
摘要： For a complex image to be complexly added, appropriate phase correction is executed by a simple method to prevent occurrence of an artifact in a signal region and to reduce noise in a background region. Two or more types of smoothing processing with different smoothing degrees are executed on a phase image of the complex image to obtain two or more types of smoothed phase images having different smoothing degrees. A weight for each of these smoothed phase images is calculated based on a signal value (SNR) of an intensity image, and addition is performed by a weight for each signal value to obtain a smoothed phase image for correction. After a phase of the complex image is corrected using the smoothed phase image, a phase-corrected complex image is complexly added. As a result, phase correction equivalent to phase correction in which a smoothing degree is weakened in the signal region and a smoothing degree is strengthened in the background region is realized.
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4.发明授权公开(公告)号：US11918337B2
公开(公告)日：2024-03-05
申请号：US17832772
申请日：2022-06-06
发明人： Toru Shirai , Suguru Yokosawa , Yukio Kaneko , Atsuro Suzuki , Tomoki Amemiya
IPC分类号： A61B5/055 , G01R33/3415 , G01R33/56 , G01R33/561 , G06T7/00
CPC分类号： A61B5/055 , G01R33/3415 , G01R33/5608 , G01R33/5611 , G06T7/0012 , G06T2207/10088
摘要： The present invention is to perform appropriate noise reduction processing on an image having different signal levels or noise levels depending on an imaging condition or a reconstruction condition. A magnetic resonance imaging apparatus according to the invention includes: a measurement unit that receives a nuclear magnetic resonance signal generated in a subject by a receiving coil; an image reconstruction unit that processes the nuclear magnetic resonance signal received by the receiving coil and reconstructs an image of the subject; an SNR spatial distribution calculation unit that calculates spatial distribution of a signal-to-noise ratio of the image using spatial distribution of a noise level and spatial distribution of the signal of the image; and a noise reduction unit that reduces noise from the image based on the spatial distribution of the signal-to-noise ratio.
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公开(公告)号：US11686801B2
公开(公告)日：2023-06-27
申请号：US17731412
申请日：2022-04-28
发明人： Shinji Kurokawa , Yasuhiro Kamada , Toru Shirai , Takenori Murase , Hiroki Shoji
IPC分类号： G01R33/56
CPC分类号： G01R33/5608
摘要： During obtaining a sensitivity distribution in a k-space, data based on which the sensitivity distribution is obtained is expanded with a mirror image to create an expanded image to prevent spectrum leakage, and the sensitivity distribution is stably calculated. During obtaining the sensitivity distribution in the k-space, image data based on which the sensitivity distribution is obtained is inverted as a mirror image to be made into the expanded image, the expanded image is transformed into k-space data, and a frequency component (frequency space data) of the sensitivity distribution is calculated. A region corresponding to the original image data is clipped from the calculated frequency space data, and the sensitivity distribution is obtained.
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6.发明公开公开(公告)号：US20230142011A1
公开(公告)日：2023-05-11
申请号：US17969884
申请日：2022-10-20
发明人： Tomoki Amemiya , Toru Shirai , Atsuro Suzuki , Yukio Kaneko , Hiroki Shoji , Keisuke Nishio
CPC分类号： G01R33/5608 , G06T11/008 , G06T2211/424
摘要： Provided is a method for performing reconstruction and noise removal with high accuracy on various undersampling patterns including equidistant undersampling. An image processing unit that processes measurement data acquired by an MRI apparatus performs image reconstruction by using measurement data on respective channels measured in a predetermined undersampling pattern and sensitivity distributions of respective reception coils. At this time, denoising of a reconstructed image and a calculation for maintaining consistency between original measurement data and the measurement data on the respective channels created from denoised images are sequentially processed. Accordingly, image restoration and denoising with high accuracy are possible without depending on the undersampling pattern.
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7.发明授权公开(公告)号：US11579231B2
公开(公告)日：2023-02-14
申请号：US17645075
申请日：2021-12-20
发明人： Ryota Satoh , Keisuke Nishio , Yasuhiro Kamada , Yoshitaka Sato , Masahiro Takizawa , Toru Shirai
IPC分类号： G01R33/565 , G01R33/56 , G01R33/561
摘要： To provide a technique in which, in imaging using an EPI method, an occurrence of an artifact when phase correction is performed for each channel is avoided and the phase correction is accurately performed. A common phase correction value to be applied to data of all channels is calculated using pre-scan data of each channel. The common phase correction value is obtained by combining a difference phase obtained for each of the channels. The difference phase is obtained by complex integration, while an absolute value of each channel is maintained as it is. The combination is performed by complex average, and averaging processing according to a weight of the absolute value is performed. The occurrence of an artifact can be prevented by using the common phase correction value, and robust phase correction can be performed by including the weight of the absolute value.
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公开(公告)号：US20240361415A1
公开(公告)日：2024-10-31
申请号：US18618225
申请日：2024-03-27
发明人： Toru Shirai , Yukio Kaneko , Yosuke Otake
IPC分类号： G01R33/565 , A61B5/00 , G01R33/56 , G06T7/11
CPC分类号： G01R33/56509 , A61B5/7475 , G01R33/5608 , G06T7/11 , G06T2207/10088 , G06T2207/30004
摘要： Provided is a weighted reconstruction technique of a channel for suppressing a blood flow artifact and a body movement artifact in imaging using a multi-channel reception coil. In a case of reconstructing an image of a subject by using a nuclear magnetic resonance signal collected by each of a plurality of channels of a reception coil, by using a positioning image, an organ or a region causing a blood flow artifact and a body movement artifact in the subject is specified, a weight of each channel is decided by using information on the specified organ or region, and weighted reconstruction is performed by using the weight.
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9.发明公开公开(公告)号：US20240361413A1
公开(公告)日：2024-10-31
申请号：US18619828
申请日：2024-03-28
发明人： Toru Shirai , Yukio Kaneko , Yosuke Otake , Suguru Yokosawa
IPC分类号： G01R33/561 , G01R33/36 , G01R33/54
CPC分类号： G01R33/5611 , G01R33/3664 , G01R33/546
摘要： Provided is an MRI apparatus that supports re-setting of an imaging condition for preventing occurrence of aliasing in a phase encoding direction. A region in which an aliasing signal causing aliasing occurs is estimated by using a FOV set at the beginning and a positioning image, a range of the FOV to be changed or a weighting amount of each channel of a reception coil is calculated based on an estimation result, and an imaging condition is changed. Thereafter, a main scan is executed, and in a case where a weight of the reception coil is changed, channel combination is performed using the changed weight.
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10.发明公开公开(公告)号：US20240273714A1
公开(公告)日：2024-08-15
申请号：US18412271
申请日：2024-01-12
发明人： Suguru Yokosawa , Atsuro Suzuki , Toru Shirai
CPC分类号： G06T7/0012 , G06T5/50 , G06T5/70 , G06V10/25 , G06T2207/20104 , G06T2207/20221 , G06T2207/20224 , G06T2207/30016
摘要： Provided is a noise-reduced image in which noise and artifacts, which pose a problem in intraoperative MRI, are reduced for each pixel in a manner desired by a user and a preference of the user for a tissue or a site that the user wants to observe is reflected. In a case of generating and presenting a third medical image by using a first medical image acquired by an MRI apparatus and a second medical image obtained by performing processing of reducing noise and artifacts with respect to the first medical image, a difference for each pixel between the first medical image and the second medical image is taken, a weighting value for each pixel is calculated using a generated difference image, and a user's change for weighting is received. The finally decided-on weighting value is used to combine the first medical image and the second medical image through weighted averaging for each pixel, and the combined image is presented.
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