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公开(公告)号：US10022099B2
公开(公告)日：2018-07-17
申请号：US14914355
申请日：2014-10-22
Applicant: Hitachi, Ltd.
Inventor： Yushi Tsubota , Fumito Watanabe , Yasutaka Konno , Shinichi Kojima , Keisuke Yamakawa , Shinji Kurokawa
IPC: A61B6/00 , A61B6/03 , G01N23/087 , G01N23/046
Abstract: A change of X-ray radiation quality due to a material existing between an X-ray source and a detection element is estimated and corrected. Accordingly, deterioration of material discrimination ability in a dual energy imaging method can be prevented. An X-ray imaging apparatus is provided with an inherent filtration calculator configured to use measured data obtained by imaging air at two or more types of different tube voltages to calculate a deviation from a reference radiation quality, as a transmission length (inherent filtration) of a predetermined reference material. A reference-material transmission-length conversion is applied to the measured data according to the dual energy imaging method, thereby calculating the reference material transmission length (inherent filtration). When a subject is imaged, the dual energy imaging is performed by adding the inherent filtration calculated as to each detection element, and this produces an image with the change of radiation quality having been corrected.
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公开(公告)号：US11944468B2
公开(公告)日：2024-04-02
申请号：US16876185
申请日：2020-05-18
Applicant: Hitachi, Ltd.
Inventor： Shinichi Kojima , Kazuma Yokoi , Isao Takahashi , Fumito Watanabe , Fuyuhiko Teramoto , Taiga Gotou
CPC classification number: A61B6/032 , A61B6/4241 , A61B6/5217 , A61B6/545
Abstract: A material decomposition apparatus for performing decomposition of a material in an object. The apparatus includes a data storage section for storing correction data preliminarily generated by decomposing one of three or more materials into the other two materials, a data input section to which radiation data of the object is inputted, the radiation data being divided into a plurality of energy levels, and a decomposition processing section for repeatedly performing two-material decomposition for decomposition of the other two materials of the three or more materials using the radiation data at different energy levels and the correction data to perform decomposition of the inside of the object into the three or more materials.
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公开(公告)号：US09977137B2
公开(公告)日：2018-05-22
申请号：US15325497
申请日：2015-07-23
Applicant: HITACHI, LTD.
Inventor： Yushi Tsubota , Shinji Kurokawa , Keisuke Yamakawa , Yasutaka Konno , Shinichi Kojima , Fumito Watanabe
CPC classification number: G01T1/2985 , A61B6/032 , A61B6/4233 , G01N23/046
Abstract: Provided is a technique in an X-ray imaging apparatus for implementing data interpolation approximating an ideal point response trajectory interpolation, along with reducing calculation load. A method is provided to perform interpolation at high speed, in a direction along the point response trajectory. Sinograms are interpolated in advance from measured data, as to representative angles (e.g., 0°, ±30°, ±60°, and 90°) only. When a pixel targeted for back projection is determined at the time of reconstruction, a slope of the point response trajectory is determined as to each view. According to the slope of the trajectory, each representative sinogram is added with weight, whereby interpolation data in association with any angle can be obtained.
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公开(公告)号：US09924917B2
公开(公告)日：2018-03-27
申请号：US14889634
申请日：2014-05-02
Applicant: Hitachi, Ltd.
Inventor： Yushi Tsubota , Fumito Watanabe , Yasutaka Konno , Shinichi Kojima , Keisuke Yamakawa
CPC classification number: A61B6/482 , A61B6/032 , A61B6/461 , A61B6/467 , A61B6/481 , A61B6/504 , A61B6/5205 , G06T11/005 , G06T2207/10081 , G06T2211/408
Abstract: The present invention is capable of distinguishing four types or more of substances such as air, water (soft tissues), contrast medium, and bones (calcification) to diagnose progress of atherosclerotic sites using dual energy imaging. A subject is imaged with two types of different tube voltages and an image obtained by image reconstruction is binarized to carry out a reprojection process; thereby, the distance of penetration of air is estimated, the contribution of air in measurement projection data is determined, and the amount of reduction by the air is deducted from the projection data so as to enable distinction between four or more substances such as air, water (soft tissues), contrast medium, and bones (calcification).
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Patent Agency Ranking
公开(公告)号：US11169284B2
公开(公告)日：2021-11-09
申请号：US16719528
申请日：2019-12-18
Applicant: Hitachi, Ltd.
Inventor： Masafumi Onouchi , Takafumi Ishitsu , Fumito Watanabe
IPC: H01J37/244 , G01T1/24 , G01T1/29 , G01T1/17
Abstract: The present invention provides a radiation imaging apparatus capable of maintaining the quality of an image obtained even when a dose incident on a radiation detector changes suddenly. The present invention is a radiation imaging apparatus including a radiation source, a radiation detector to detect radiation emitted from the radiation source, and a cooling unit to cool the radiation detector; and is characterized in that the radiation detector has a counting circuit to output a number of photons in radiation counted per unit time as a photon counting rate, and the cooling unit controls a coolability of the radiation detector in response to the photon counting rate.
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公开(公告)号：US11029423B2
公开(公告)日：2021-06-08
申请号：US16808774
申请日：2020-03-04
Applicant: Hitachi, Ltd.
Inventor： Masafumi Onouchi , Takafumi Ishitsu , Fumito Watanabe
IPC: G01T1/24
Abstract: To provide a radiation imaging system which is adapted to downsize a photon counting radiation detector including a semiconductor layer for detecting photons of radiation and a collimator for suppressing incidence of scattered rays, and which ensures high voltage resistance. The radiation imaging system includes: a radiation source; a radiation detector; and a support portion for supporting the radiation source and the radiation detector in opposed relation. The system has a structure wherein the radiation detector includes a plurality of detecting element modules arranged in an arcuate form. The detecting element module includes a base fixed to the support portion; a semiconductor layer; a high-voltage wire for supplying high voltage to the semiconductor layer; a collimator for suppressing scattered rays, and a supporting column disposed at place within a predetermined distance from the semiconductor layer.
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公开(公告)号：US10905388B2
公开(公告)日：2021-02-02
申请号：US16305777
申请日：2017-09-08
Applicant: HITACHI, LTD.
Inventor： Shinichi Kojima , Fumito Watanabe , Yasutaka Konno , Isao Takahashi , Kazuma Yokoi
Abstract: X-ray photons are counted as to each of energy bands (bins) to which optimum energy ranges are provided, and an image with reduced noise is displayed in a short time. An energy range of at least one of multiple energy bands in an X-ray detector is adjusted, on the basis of a distribution of degrees of X-ray attenuation at respective energy levels, the distribution of degrees of X-ray attenuation being measured in advance with respect to a predetermined direction of a subject. By using the X-ray detector with the energy bands after the adjustment, photon-counting CT imaging is performed.
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公开(公告)号：US10542947B2
公开(公告)日：2020-01-28
申请号：US16071810
申请日：2016-11-17
Applicant: Hitachi, Ltd.
Inventor： Shinichi Kojima , Yasutaka Konno , Fumito Watanabe , Isao Takahashi
Abstract: The present invention is directed to make a photon-counting CT apparatus capable of more accurate data acquisition. Such apparatus is provided with a reference detection unit and a time measuring instrument to measure temporal fluctuations in a rotational direction of an X-ray irradiation unit. The apparatus corrects temporal fluctuations in the rotational direction involved in data measured by the reference detection unit, using time measurement data which is output by the time measuring instrument. Using corrected measurement data measured by the reference detection unit, the apparatus makes corrections of fluctuations pertaining to the X-ray tube of the X-ray irradiation unit and pile-up. Data corrections with high accuracy are thus enabled.
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公开(公告)号：US10302779B2
公开(公告)日：2019-05-28
申请号：US15518575
申请日：2015-06-18
Applicant: HITACHI, LTD.
Inventor： Isao Takahashi , Kazuma Yokoi , Eiji Moro , Yuichiro Ueno , Yasutaka Konno , Fumito Watanabe , Shinichi Kojima
IPC: G01T1/29 , H01L31/115 , G01T1/161 , G01T1/17 , G01T1/20 , H01L27/146 , A61B6/03 , A61B6/00
Abstract: A flat pixel (20) is a single unit composing a radiation detector and is configured so as to be divided into at least four subpixels (21) such that even if a prescribed number of subpixels (21) are removed from each pixel (20) in order of largest effective area, the centroid (51) of the effective area of the entirety of the remaining subpixels (21) is positioned within a similar-shape region (30) having the same centroid (50) as the pixel (20) and having sides of lengths that are half those of the pixel (20).
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