公开(公告)号：US20210106292A1

公开(公告)日：2021-04-15

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

IPC: A61B6/03 ,  A61B6/00

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.

公开(公告)号：US20170119335A1

公开(公告)日：2017-05-04

申请号：US15123192

申请日：2015-02-04

Applicant: HITACHI, LTD.

Inventor： Keisuke YAMAKAWA ,  Shinichi KOJIMA

IPC: A61B6/00 ,  A61B6/03

CPC classification number: A61B6/5258 ,  A61B6/032 ,  A61B6/461 ,  A61B6/467 ,  A61B6/5205 ,  G06T11/006 ,  G06T2211/424

Abstract: This X-ray CT device uses iterative reconstruction to obtain a CT image with the desired noise reduction or X-ray reduction ratio. An iterative approximation reconstruction unit (136) is provided which, from measured projection data obtained by an X-ray detection unit of the X-ray CT device, iteratively reconstructs a CT image in a reconstruction range of a subject, and iteratively corrects the CT image such that calculated projection data, calculated through forward projection of a CT image, is the same as the difference between measured projection data detected by the X-raw detection unit and calculated projection data. The iterative approximation reconstruction unit is provided with a parameter determination unit (151), an iterative correction unit (152), and a table unit (153) which calculates in advance the relation between each parameter used in the iterative reconstruction, and noise reduction or X-ray reduction ratio in the CT image. The parameter determination unit (151) determines the parameters from a calculation table in the table unit (153) depending on the desired reduction ratio.

公开(公告)号：US20200323502A1

公开(公告)日：2020-10-15

申请号：US16305777

申请日：2017-09-08

Applicant: HITACHI, LTD.

Inventor： Shinichi KOJIMA ,  Fumito WATANABE ,  Yasutaka KONNO ,  Isao TAKAHASHI ,  Kazuma YOKOI

IPC: A61B6/00 ,  A61B6/03 ,  A61B6/02

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.

公开(公告)号：US20200015769A1

公开(公告)日：2020-01-16

申请号：US16439748

申请日：2019-06-13

Applicant: Hitachi, Ltd.

Inventor： Shinichi KOJIMA ,  Fumito WATANABE ,  Kazuma YOKOI ,  Fuyuhiko TERAMOTO

IPC: A61B6/00

Abstract: To provide an X-ray CT apparatus capable of correcting a difference of scattered radiation quantities contained in the projection data even in a case where a plurality of detection elements are disposed between collimator plates. The X-ray CT apparatus includes: an X-ray irradiation section for X-ray radiation; an X-ray detector including a plurality of detection elements for detecting the X-ray; a plurality of collimator plates disposed between the X-ray irradiation section and the X-ray detector so as to reduce scattered radiation; a reconstruction portion for reconstructing a tomographic image by using projection data generated based on an output from the X-ray detector; and a correction portion for correcting the projection data by using different correction functions according to the positions of the plural detection elements disposed between the collimator plates.

公开(公告)号：US20180220979A1

公开(公告)日：2018-08-09

申请号：US15504827

申请日：2015-08-06

Applicant: Hitachi, Ltd.

Inventor： Shinichi KOJIMA ,  Keisuke YAMAKAWA

IPC: A61B6/00 ,  A61B6/03

CPC classification number: A61B6/4241 ,  A61B6/032 ,  A61B6/463 ,  A61B6/542

Abstract: Provided is a photon counting CT device for estimating an exposure dose to a subject, precisely in a simple configuration, irrespective of a spectrum shape of X-rays being applied. An exposure dose derived from the X-rays with predetermined intensity is obtained in every energy range provided in advance, and held as exposure per band data. When an imaging condition is provided, X-rays are applied in accordance with the imaging condition thus provided, and a photon count (intensity) of the incident X-rays as to each energy range is obtained, in the shape of spectrum of the X-rays applied to a detector without placing the subject. The intensity of the incident X-rays is multiplied by the exposure per band, and the results as to all the energy ranges are added up. Accordingly, the exposure dose caused by the X-rays being applied in accordance with the provided imaging condition is estimated.

公开(公告)号：US20170276808A1

公开(公告)日：2017-09-28

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 ,  H01L27/146 ,  G01T1/161 ,  G01T1/20

CPC classification number: G01T1/2985 ,  A61B6/032 ,  A61B6/4208 ,  G01T1/161 ,  G01T1/17 ,  G01T1/2018 ,  H01L27/14658 ,  H01L31/115

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).

公开(公告)号：US20190021685A1

公开(公告)日：2019-01-24

申请号：US16071810

申请日：2016-11-17

Applicant: Hitachi, Ltd.

Inventor： Shinichi KOJIMA ,  Yasutaka KONNO ,  Fumito WATANABE ,  Isao TAKAHASHI

IPC: A61B6/00 ,  A61B6/03 ,  G06T11/00

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.

公开(公告)号：US20170176609A1

公开(公告)日：2017-06-22

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

IPC: G01T1/29 ,  G01N23/04 ,  A61B6/00 ,  A61B6/03

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.

公开(公告)号：US20180174335A1

公开(公告)日：2018-06-21

申请号：US15580488

申请日：2016-06-06

Applicant: Hitachi, Ltd.

Inventor： Keisuke YAMAKAWA ,  Shinichi KOJIMA

IPC: G06T11/00 ,  A61B6/03 ,  A61B6/00 ,  G06T5/00

CPC classification number: G06T11/006 ,  A61B6/032 ,  A61B6/5205 ,  A61B6/5258 ,  G06T5/002 ,  G06T2207/10081 ,  G06T2211/424

Abstract: High-quality image and low radiation exposure are achieved without increasing man-hours and data amount to be held. A table of iterative correction parameters optimized in the representative imaging conditions is held and an iterative correction parameter optimized in the actual imaging conditions is determined from the iterative correction parameters held in the table. In addition to the parameter table, a reference weight is also held and is reflected to generate the iterative correction parameter for each pixel position.