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公开(公告)号：US20200219251A1
公开(公告)日：2020-07-09
申请号：US16628254
申请日：2018-04-09
Applicant: Hitachi, Ltd.
Inventor： Hisashi TAKAHASHI , Taiga GOTOU , Koichi HIROKAWA
Abstract: An image is generated where an edge of a structure in a subject is sharpened with reducing streak artifacts, within a short amount of time. X-rays at multiple angles are applied to the subject placed in imaging space, and a distribution of X-rays strength passing through the subject is detected to obtain raw data associated with multiple views. After smoothing the raw data associated with multiple views, image reconstruction is performed to generate a smoothed image of a predetermined region to be imaged in the imaging space. In the smoothed image, more intense sharpening process is applied to pixels in a region of a central part of the subject, than the pixels in a region of a peripheral part of the subject.
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公开(公告)号：US20180165807A1
公开(公告)日：2018-06-14
申请号：US15580337
申请日：2016-06-22
Applicant: HITACHI, LTD.
Inventor： Hisashi TAKAHASHI , Taiga GOTO , Koichi HIROKAWA
CPC classification number: G06T7/0012 , A61B6/032 , A61B6/06 , A61B6/4035 , A61B6/5205 , A61B6/583 , G01R33/4812 , G01R33/5608 , G06T5/003 , G06T11/006 , G06T2211/424
Abstract: A reconstruction image is generated with a small number of updates, with the use of an iterative approximation method. A specified tomographic image of a subject is received, and a process is performed two or more times, where an update process is performed according to the iterative approximation method, using the tomographic image as an initial image and an update image is obtained. Then, an update vector corresponding to a difference between thus generated update images of the update process performed twice is multiplied by predetermined coefficients, so as to generate an estimated update vector. Using this vector, an update image is generated. Then, this update image is used as a new initial image, and a process is repeated where the update process is performed according to the iterative approximation method and an update image is obtained, thereby generating a tomographic image of the subject.
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公开(公告)号：US20190180482A1
公开(公告)日：2019-06-13
申请号：US16309780
申请日：2017-06-16
Applicant: Hitachi, Ltd.
Inventor： Hisashi TAKAHASHI , Taiga GOTO , Koichi HIROKAWA
Abstract: In order to determine noise intensity more accurately by a projection data division method using data after fan-parallel conversion, a plurality of projection data obtained by irradiating a scan object with radiations are received and subjected to prescribed data conversion; data after the conversion is divided into two or more sets; a reconstructed image is generated for each set of data; and the generated reconstructed image for each of the sets is subtracted to generate a difference image. An index indicating pixel value variation for at least one prescribed region on the difference image is calculated, the value of the index is corrected by a previously calculated correction value, and the corrected index value is regarded as noise intensity of the region.
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公开(公告)号：US20210027430A1
公开(公告)日：2021-01-28
申请号：US16897768
申请日：2020-06-10
Applicant: Hitachi, Ltd.
Inventor： Mariko YAMAMOTO , Keisuke YAMAKAWA , Isao TAKAHASHI , Taiga GOTOU , Hisashi TAKAHASHI
Abstract: Noise is reduced for a medical image for which noise cannot be quantified by a general-purpose image quality evaluation index. An image processor has a preprocessor that generates input images including an original image and one or more images with reduced noise compared with the original image; and a noise reduction processor outputs an image, which is obtained by reducing noise from the original image based on the input images, by applying a learned network. The learned network used in the noise reduction processor is constructed by performing deep learning using a plurality of learning sets in which one or more of a medical image including noise, a noise-reduced image obtained by performing noise reduction processing on the medical image, and an intermediate image obtained during the noise reduction processing are input images and a correct image is obtained based on the input images an output image.
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公开(公告)号：US20170273657A1
公开(公告)日：2017-09-28
申请号：US15509115
申请日：2015-10-07
Applicant: HITACHI, LTD.
Inventor： Taiga GOTO , Hisashi TAKAHASHI , Koichi HIROKAWA
CPC classification number: A61B6/582 , A61B6/032 , A61B6/488 , A61B6/5205 , A61B6/5258 , A61B6/5294 , A61B6/585
Abstract: In order to provide a data processing device and the like, capable of performing highly accurate reference correction even in a case where an object protrudes in reference channels in most of the measurement views, an image processing device (data processing device) of an X-ray CT apparatus calculates a unit air calibration reference value which is a value per unit tube current of an air calibration reference value which is reference data measured during air calibration, calculates a reference value (estimated reference value) corresponding to an X-ray condition in the main scanning on the basis of an output tube current value in the main scanning and a unit air calibration reference value, and corrects normalized reference data obtained by normalizing a measured reference value in the main scanning with the estimated reference value, to be included in an allowable error range, so as to remove the influence of protrusion.
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Patent Agency Ranking
公开(公告)号：US20170202532A1
公开(公告)日：2017-07-20
申请号：US15321401
申请日：2015-07-10
Applicant: HITACHI, LTD.
Inventor： Taiga GOTO , Hisashi TAKAHASHI , Koichi HIROKAWA
CPC classification number: A61B6/5294 , A61B6/032 , A61B6/0457 , A61B6/5205 , A61B6/545 , G06T11/003 , G06T11/006 , G06T2211/424
Abstract: In order to provide a data processing method and the like capable of suppressing high-frequency errors such as moiré using data uniformly by presuming that adjacent pixels and beams overlap and performing calculation in a back projection process or a forward projection process for reconstructing images, the image processing device 122 sets a pixel size wider than a pixel interval, performs the back projection process or the forward projection process for calculating an interpolation value to be assigned to the pixels or the beams using a size-dependent weight (pixel window) according to an overlap amount of the adjacent pixels, sets a beam size wider than a beam interval, and then performs the back projection process or the forward projection process for calculating an interpolation value to be assigned to the pixels or the beams using a size-dependent weight (beam window) according to an overlap amount of the adjacent beams.
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公开(公告)号：US20210110516A1
公开(公告)日：2021-04-15
申请号：US16464322
申请日：2017-12-01
Applicant: Hitachi, Ltd.
Inventor： Taiga GOTO , Hisashi TAKAHASHI
Abstract: Even a windmill artifact including a high-frequency component in a plane perpendicular to a rotation axis can be reduced and a boundary of an organ can be made to be clear to maintain the contrast.
The invention relates to a medical image processing device and includes an image acquiring unit that acquires a 3D volumetric image, a Z high-frequency image generating unit that generates a Z high-frequency image which is a high-frequency component in a rotation axis direction from the 3D volumetric image, an organ component extracting unit that extracts an organ component from the Z high-frequency image, an artifact component extracting unit that extracts an artifact component on the basis of the Z high-frequency image and the organ component, and a corrected image generating unit that generates a corrected image by subtracting the artifact component from the 3D volumetric image.-
公开(公告)号：US20200151920A1
公开(公告)日：2020-05-14
申请号：US16666931
申请日：2019-10-29
Applicant: Hitachi, Ltd.
Inventor： Hisashi TAKAHASHI , Taiga GOTOU
Abstract: The present invention provides an image reconstruction apparatus and an image reconstruction method, both of which achieve reduction in a granular noise and a streak-like artifact both contained in a reconstruction image, and a clear structure boundary as well The image reconstruction apparatus configured to generate a reconstruction image includes a noise reduction section that generates a streak reduction image as an image obtained by reducing a streak-like artifact in the reconstruction image, a noise reduction ratio acquisition section that acquires a first noise reduction ratio as a noise reduction ratio to be used for reducing a granular noise while retaining a structure boundary in the reconstruction image, and a second noise reduction ratio as a noise reduction ratio to be used for generating the streak reduction image, and an image addition section that adds an addition image to be generated based on the first noise reduction ratio and the second noise reduction ratio to the streak reduction image.
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9.发明申请公开(公告)号：US20180350113A1
公开(公告)日：2018-12-06
申请号：US15562325
申请日：2016-02-29
Applicant: HITACHI, LTD.
Inventor： Taiga GOTO , Hisashi TAKAHASHI , Hideaki FUJII
CPC classification number: G06T11/008 , A61B6/032 , A61B6/5258 , A61B6/5282 , G06T11/006
Abstract: In order to reduce a metal artifact using a short process, without causing image quality deterioration, when a subject containing metal is imaged in an X-ray CT apparatus, the invention is such that a high frequency component is extracted utilizing the fact that a high frequency component is a structure in error projection data, which are a difference between primary corrected projection data wherein at least one portion of an artifact component caused by metal has been removed and photographed projection data acquired by imaging. The high frequency component, extracted while carrying out weighting in order to suppress the metal artifact, is restored to the primary corrected projection data, after which an image is reconstructed. Also, metal projection data used when compiling the primary corrected projection data are calculated from a value that is a CT value corresponding to soft tissue subtracted from a CT value of a metal region.
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公开(公告)号：US20170135664A1
公开(公告)日：2017-05-18
申请号：US15321903
申请日：2015-07-23
Applicant: HITACHI, LTD.
Inventor： Hisashi TAKAHASHI , Taiga GOTO , Koichi HIROKAWA
CPC classification number: A61B6/5258 , A61B6/032 , A61B6/0407 , A61B6/461
Abstract: An X-ray CT apparatus includes an extraction unit that acquires air data measured using the X-ray CT apparatus and the measurement data obtained by scanning the object, that extracts sensitivity variation data which is a sensitivity variation component of a detection element from the air data, and that extracts blank data from which the sensitivity variation component is removed, and a projection data generation unit that removes the sensitivity variation component and noise which are included in the measurement data, based on the sensitivity variation data, and that uses the blank data so as to perform a correction process of the measurement data from which the sensitivity variation component and the noise are removed.
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