Patents by Inventor Ryota Kohara

Ryota Kohara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20230329662
    Abstract: When motion information of a subject during scanning is acquired from an image pair and motion-corrected image reconstruction is performed to generate a CT image, erroneous recognition and excessive smoothing of a motion component are prevented, and the accuracy of motion correction is improved. A filtering unit for reducing noise of the image pair is provided. The filtering unit acquires a relation between indicators for noise amounts acquired based on information that affects noise amounts of a first image and a second image constituting the image pair, and adjusts smoothness of each image using the relation between the indicators. The presence or absence of a motion is determined for the image pair subjected to noise reduction by filtering, normalization degrees of the two images are made different according to the presence or absence of the motion and the two images are normalized, and the magnitude and a direction of the motion are detected.
    Type: Application
    Filed: April 5, 2023
    Publication date: October 19, 2023
    Inventors: Yusuke Tetsumura, Ryota Kohara, Yuta Ogura, Yoshiki Mori
  • Patent number: 11123024
    Abstract: Arrangement to reduce a time until a first image is displayed, to reduce a standby time until the next imaging is started, and to uniformize a time interval in a case where a plurality of images are displayed. An X-ray CT device detects a dose of an X-ray, a storage unit that preserves image data, a calculation unit that generates, as the image data, projection data on the basis of the X-ray data in parallel to an imaging process in the scanner, preserves the projection data, notifies a display control unit of preservation information, performs a reconstruction process, a display unit that displays an image generated per the X-ray data, and the display control unit that controls a display timing of a reconstructed image to be displayed on the display unit on the basis of the preservation information and the reconstruction information.
    Type: Grant
    Filed: December 5, 2017
    Date of Patent: September 21, 2021
    Assignee: Hitachi, Ltd.
    Inventors: Ryota Kohara, Tsuyoshi Suzuki, Yuta Ogura
  • Publication number: 20190383755
    Abstract: Arrangement to reduce a time until a first image is displayed, to reduce a standby time until the next imaging is started, and to uniformize a time interval in a case where a plurality of images are displayed. An X-ray CT device detects a dose of an X-ray, a storage unit that preserves image data, a calculation unit that generates, as the image data, projection data on the basis of the X-ray data in parallel to an imaging process in the scanner, preserves the projection data, notifies a display control unit of preservation information, performs a reconstruction process, a display unit that displays an image generated per the X-ray data, and the display control unit that controls a display timing of a reconstructed image to be displayed on the display unit on the basis of the preservation information and the reconstruction information.
    Type: Application
    Filed: December 5, 2017
    Publication date: December 19, 2019
    Applicant: Hitachi, Ltd.
    Inventors: Ryota KOHARA, Tsuyoshi SUZUKI, Yuta OGURA
  • Patent number: 10070841
    Abstract: In order to provide an arithmetic device, an X-ray CT apparatus, and an image reconstruction method, capable of reducing processing time while maintaining a noise reduction effect, in a successive approximation image reconstruction method (separable paraboloidal surrogate (SPS) method) of the related art, updated images are forward-projected, whenever images are repeatedly updated, a difference between forward projection data and original object projection data is back-projected so that a difference image is obtained, and a forward projection process and a back projection process are repeatedly performed, but, in the present invention, a forward projection process and a back projection process requiring calculation time are replaced with a process requiring a relatively small calculation amount, such as a difference between an updated image and a reference image, and, as a result, it is possible to considerably reduce a calculation amount in a successive approximation image reconstruction process and to reduc
    Type: Grant
    Filed: February 2, 2016
    Date of Patent: September 11, 2018
    Assignee: HITACHI, LTD.
    Inventors: Ryota Kohara, Tsuyoshi Suzuki, Yuta Ogura
  • Publication number: 20170347986
    Abstract: In order to provide an arithmetic device, an X-ray CT apparatus, and an image reconstruction method, capable of reducing processing time while maintaining a noise reduction effect, in a successive approximation image reconstruction method (separable paraboloidal surrogate (SPS) method) of the related art, updated images are forward-projected, whenever images are repeatedly updated, a difference between forward projection data and original object projection data is back-projected so that a difference image is obtained, and a forward projection process and a back projection process are repeatedly performed, but, in the present invention, a forward projection process and a back projection process requiring calculation time are replaced with a process requiring a relatively small calculation amount, such as a difference between an updated image and a reference image, and, as a result, it is possible to considerably reduce a calculation amount in a successive approximation image reconstruction process and to reduc
    Type: Application
    Filed: February 2, 2016
    Publication date: December 7, 2017
    Inventors: Ryota KOHARA, Tsuyoshi SUZUKI, Yuta OGURA
  • Patent number: 9715745
    Abstract: To provide an X-ray CT apparatus that can reduce calculation time required for an iterative approximation projection data correction process by restricting a range for the iterative approximation projection data correction process and generate low-noise images according to the examination purpose, the calculation device of the X-ray CT apparatus generates correction projection data by performing an iterative approximation projection data correction process for projection data acquired in scanning and reconstructs CT images using the correction projection data. The calculation device determines a range to which iterative approximation projection data correction process is applied based on scanning conditions and reconstruction conditions. For example, a slice direction application range is determined based on an X-ray beam width, and a channel direction application range is determined based on an FOV.
    Type: Grant
    Filed: January 29, 2014
    Date of Patent: July 25, 2017
    Assignee: HITACHI, LTD.
    Inventor: Ryota Kohara
  • Patent number: 9592026
    Abstract: In order to provide an X-ray CT apparatus or the like capable of improving the image quality even with low-exposure scanning by reducing artifacts generated around high absorbers on an image while reducing the amount of image noise, a reconstruction arithmetic device 221 sets the number of iterations of iterative processing for correcting projection data, and calculates, as calibration coefficients, a correction coefficient ? and an adjustment coefficient ? for adjusting the application ratio of noise reduction processing f1 and signal strength maintenance processing f2 included in the iterative processing. By performing the iterative processing including the noise reduction processing f1 and signal strength maintenance processing f2 on the projection data based on the number of iterations and the calibration coefficients ? and ?, corrected projection data is created, and a CT image is reconstructed.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: March 14, 2017
    Assignee: HITACHI, LTD.
    Inventors: Yuta Ogura, Ryota Kohara
  • Publication number: 20160278733
    Abstract: In order to provide an X-ray CT apparatus or the like capable of improving the image quality even with low-exposure scanning by reducing artifacts generated around high absorbers on an image while reducing the amount of image noise, a reconstruction arithmetic device 221 sets the number of iterations of iterative processing for correcting projection data, and calculates, as calibration coefficients, a correction coefficient ? and an adjustment coefficient a? for adjusting the application ratio of noise reduction processing f1 and signal strength maintenance processing f2 included in the iterative processing. By performing the iterative processing including the noise reduction processing f1 and signal strength maintenance processing f2 on the projection data based on the number of iterations and the calibration coefficients ? and ?, corrected projection data is created, and a CT image is reconstructed.
    Type: Application
    Filed: March 13, 2014
    Publication date: September 29, 2016
    Applicant: HITACHI MEDICAL CORPORATION
    Inventors: Yuta Ogura, Ryota KOHARA
  • Patent number: 9430855
    Abstract: In order to provide an X-ray CT apparatus and the like that can specify an optimal cardiac phase in a wide variety of cases, an X-ray CT apparatus collects X-ray information and electrocardiographic waveform data 5 by performing cardiac scanning using an scanning unit 1 (step S11). Then, reconstructed images of a plurality of cardiac phases are created (step S12), and a region-of-interest image is generated by extracting a region of interest for each of the reconstructed images of the plurality of cardiac phases (step S13). Then, a variation distribution image is generated by calculating a variation for each region-of-interest image (step S14). Then, the degree of harmony of each cardiac phase is calculated using the variation distribution image (step S15). Then, an optimal cardiac phase is determined on the basis of at least the degree of harmony (step S16).
    Type: Grant
    Filed: June 19, 2012
    Date of Patent: August 30, 2016
    Assignee: HITACHI MEDICAL CORPORATION
    Inventor: Ryota Kohara
  • Publication number: 20150348291
    Abstract: To provide an X-ray CT apparatus that can reduce calculation time required for an iterative approximation projection data correction process by restricting a range for the iterative approximation projection data correction process and generate low-noise images according to the examination purpose, the calculation device of the X-ray CT apparatus generates correction projection data by performing an iterative approximation projection data correction process for projection data acquired in scanning and reconstructs CT images using the correction projection data. The calculation device determines a range to which iterative approximation projection data correction process is applied based on scanning conditions and reconstruction conditions. For example, a slice direction application range is determined based on an X-ray beam width, and a channel direction application range is determined based on an FOV.
    Type: Application
    Filed: January 29, 2014
    Publication date: December 3, 2015
    Inventor: Ryota Kohara
  • Patent number: 9119560
    Abstract: An X-ray CT apparatus of the present invention includes an image reconstruction unit that, according to scanning conditions, acquires an irradiated X-ray image which is the distribution of the irradiation intensity of X-rays irradiated to an object by an X-ray irradiation unit, performs projection conversion of the irradiated X-ray image and a reconstructed image, and generates an exposure dose image, which is an image showing the distribution of an exposure dose of the object, and also calculates the exposure dose using the projection-converted reconstructed image and an irradiated X-ray image corresponding to a generation region of the reconstructed image.
    Type: Grant
    Filed: September 1, 2011
    Date of Patent: September 1, 2015
    Assignee: HITACHI MEDICAL CORPORATION
    Inventor: Ryota Kohara
  • Patent number: 8830263
    Abstract: The medical image display device is provided with a medical image reading unit configured to read a medical image obtained by a medical image diagnostic apparatus, a projected image creating unit configured to project the medical image onto a projection plane to created the projected image, and a projected image display unit configured to display the projected image, wherein the projected image creating unit has a virtual liquid generating unit configured to generate virtual liquid, the light transmittance of which is not zero and a virtual liquid adding unit configured to add the virtual liquid to the surface of an organ within the medical image, and creates a projected image of the medical image to which the virtual liquid has been added.
    Type: Grant
    Filed: July 21, 2010
    Date of Patent: September 9, 2014
    Assignee: Hitachi Medical Corporation
    Inventors: Ryota Kohara, Hiroto Kokubun, Nobutaka Abe, Takashi Shirahata, Tetsuo Nakazawa
  • Publication number: 20140192951
    Abstract: In order to provide an X-ray CT apparatus and the like that can specify an optimal cardiac phase in a wide variety of cases, an X-ray CT apparatus collects X-ray information and electrocardiographic waveform data 5 by performing cardiac scanning using an scanning unit 1 (step S11). Then, reconstructed images of a plurality of cardiac phases are created (step S12), and a region-of-interest image is generated by extracting a region of interest for each of the reconstructed images of the plurality of cardiac phases (step S13). Then, a variation distribution image is generated by calculating a variation for each region-of-interest image (step S14). Then, the degree of harmony of each cardiac phase is calculated using the variation distribution image (step S15). Then, an optimal cardiac phase is determined on the basis of at least the degree of harmony (step S16).
    Type: Application
    Filed: June 19, 2012
    Publication date: July 10, 2014
    Applicant: HITACHI MEDICAL CORPORATION
    Inventor: Ryota Kohara
  • Publication number: 20130156149
    Abstract: An X-ray CT apparatus of the present invention includes an image reconstruction uJnit that, according to scanning conditions, acquires an irradiated X-ray image which is the distribution of the irradiation intensity of X-rays irradiated to an object by an X-ray irradiation unit, performs projection conversion of the irradiated X-ray image and a reconstructed image, and generates an exposure dose image, which is an image showing the distribution of an exposure dose of the object, and also calculates the exposure dose using the projection-converted reconstructed image and an irradiated X-ray image corresponding to a generation region of the reconstructed image.
    Type: Application
    Filed: September 1, 2011
    Publication date: June 20, 2013
    Inventor: Ryota Kohara
  • Publication number: 20120127200
    Abstract: The medical image display device is provided with a medical image reading unit configured to read a medical image obtained by a medical image diagnostic apparatus, a projected image creating unit configured to project the medical image onto a projection plane to created the projected image, and a projected image display unit configured to display the projected image, wherein the projected image creating unit has a virtual liquid generating unit configured to generate virtual liquid, the light transmittance of which is not zero and a virtual liquid adding unit configured to add the virtual liquid to the surface of an organ within the medical image, and creates a projected image of the medical image to which the virtual liquid has been added.
    Type: Application
    Filed: July 21, 2010
    Publication date: May 24, 2012
    Inventors: Ryota Kohara, Hiroto Kokubun, Nobutaka Abe, Takashi Shirahata, Tetsuo Nakazawa
  • Patent number: 7999235
    Abstract: A nuclear medicine diagnosis apparatus comprising a mechanical collimator for effecting passage in a given direction of photons with given energy emitted from an object injected or dosed with a drug containing a radioactive isotope; a former-stage detector for detecting positional information at a point of reaction of photons having passed through the mechanical collimator and information on the momentum of charged particles generated by the reaction; a latter-stage detector disposed in the subsequent stage of the former-stage detector to detect information on the photons having been scattered by the former-stage detector; and image reconstruction means for reconstructing an image from detection information having been collected from the former-stage detector and latter-stage detector, wherein the image reconstruction means is built so that differentiation is carried out on the information on the photons having passed through the mechanical collimator and the information on the photons having been scattered b
    Type: Grant
    Filed: September 19, 2007
    Date of Patent: August 16, 2011
    Assignee: Hitachi Medical Corporation
    Inventors: Ryota Kohara, Takashi Shirahata, Tetsuo Nakazawa, Osamu Miyazaki
  • Patent number: 7750308
    Abstract: A Compton camera device according to the invention includes first means for reading coordinate data of a scattering point of a quantum ray detected by a pre-stage detector for each Compton scattering event, second means for reading coordinate data of a reaching point of the Compton-scattered quantum ray detected by a post-stage detector for each Compton scattering event, and third means for calculating a measurement accuracy of the scattered quantum ray by the first and second means for each Compton scattering event, calculating a statistical quantity of the quantum ray for each calculated measurement accuracy, and outputting the calculated statistical quantity to image reconstruction means.
    Type: Grant
    Filed: June 11, 2007
    Date of Patent: July 6, 2010
    Assignee: Hitachi Medical Corporation
    Inventors: Takashi Shirahata, Ryota Kohara, Tetsuo Nakazawa, Osamu Miyazaki
  • Publication number: 20100019156
    Abstract: A nuclear medicine diagnosis apparatus comprising a mechanical collimator for effecting passage in a given direction of photons with given energy emitted from an object injected or dosed with a drug containing a radioactive isotope; a former-stage detector for detecting positional information at a point of reaction of photons having passed through the mechanical collimator and information on the momentum of charged particles generated by the reaction; a latter-stage detector disposed in the subsequent stage of the former-stage detector to detect information on the photons having been scattered by the former-stage detector; and image reconstruction means for reconstructing an image from detection information having been collected from the former-stage detector and latter-stage detector, wherein the image reconstruction means is built so that differentiation is carried out on the information on the photons having passed through the mechanical collimator and the information on the photons having been scattered b
    Type: Application
    Filed: September 19, 2007
    Publication date: January 28, 2010
    Inventors: Ryota Kohara, Takashi Shirahata, Tetsuo Nakazawa, Osamu Miyazaki
  • Publication number: 20090202041
    Abstract: A Compton camera device according to the invention includes first means for reading coordinate data of a scattering point of a quantum ray detected by a pre-stage detector for each Compton scattering event, second means for reading coordinate data of a reaching point of the Compton-scattered quantum ray detected by a post-stage detector for each Compton scattering event, and third means for calculating a measurement accuracy of the scattered quantum ray by the first and second means for each Compton scattering event, calculating a statistical quantity of the quantum ray for each calculated measurement accuracy, and outputting the calculated statistical quantity to image reconstruction means.
    Type: Application
    Filed: June 11, 2007
    Publication date: August 13, 2009
    Inventors: Takashi Shirahata, Ryota Kohara, Tetsuo Nakazawa, Osamu Miyazaki