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

IPC: G06T7/00 ,  G01R33/48 ,  A61B6/03 ,  G06T5/00

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.

公开(公告)号：US20170231581A1

公开(公告)日：2017-08-17

申请号：US15503041

申请日：2015-06-15

Applicant: HITACHI, LTD.

Inventor： Xingdong SHENG ,  Yingjie HAN ,  Taiga GOTO ,  Keisuke YAMAKAWA

IPC: A61B6/03 ,  G06T7/70 ,  G06T11/00

CPC classification number: A61B6/032 ,  A61B6/03 ,  A61B6/5264 ,  G06T7/70 ,  G06T11/003 ,  G06T11/006 ,  G06T2207/10081 ,  G06T2207/30004 ,  G06T2211/424

Abstract: A CT image reconstructing method, a CT image reconstructing device and a CT system are provided for reducing motion artifacts in CT images in case of motion of an object. The CT image reconstructing method reconstructs CT images from projection data obtained by X-ray scanning, including a moving object position detecting step for detecting a position of a moving object in a CT image; a partial angle selecting step for selecting a view point and an angle range according to said position of the moving object and selecting data of partial angles in said projection data according to said view point and said angle range; a partial angle constraint step for generating partial angles constraint conditions according to the data of said partial angles; and an iterative reconstruction step for generating CT images by iterative reconstruction, thereby improving temporal resolution of CT images of moving objects and reducing motion artifacts.

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

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

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.

公开(公告)号：US20180110480A1

公开(公告)日：2018-04-26

申请号：US15542962

申请日：2016-02-01

Applicant: HITACHI, LTD.

Inventor： Tsuyoshi SUZUKI ,  Fuyuhiko TERAMOTO ,  Yuko AOKI ,  Taiga GOTO

IPC: A61B6/03 ,  G06T11/00 ,  G06T7/246 ,  G06T5/00 ,  G06T7/00 ,  G06T1/00

CPC classification number: A61B6/032 ,  A61B6/5205 ,  G06T1/0007 ,  G06T5/002 ,  G06T7/246 ,  G06T7/97 ,  G06T11/006 ,  G06T11/008 ,  G06T2207/10081

Abstract: In order to provide an X-ray CT apparatus which can reconstruct a tomographic image with less unevenness in image quality at a high speed on the basis of projection data which is obtained by irradiating an object with X-rays, the X-ray CT apparatus of the invention includes an inverse projection phase width setting unit that sets an inverse projection phase width which is an angular width of projection data used for reconstruction, for each tomographic image, and a view weight calculation unit that calculates a view weight which is a weight coefficient multiplied by projection data within the inverse projection phase width and is a function of a view angle, for each position of a pixel of a tomographic image.

公开(公告)号：US20170000428A1

公开(公告)日：2017-01-05

申请号：US15102597

申请日：2015-01-08

Applicant: HITACHI, LTD.

Inventor： Taiga GOTO

IPC: A61B6/02 ,  A61B6/00 ,  A61B6/03

CPC classification number: A61B6/027 ,  A61B6/032 ,  A61B6/035 ,  A61B6/481 ,  A61B6/54 ,  A61B6/541

Abstract: In order to provide an X-ray CT apparatus and a contrast enhanced scanning method that can obtain an image having a favorable contrast effect without re-injecting contrast medium even when a scanning position overtakes a position of the contrast medium during scanning using the contrast medium, the X-ray CT apparatus determines whether or not a current scanning position overtakes the contrast medium during main scanning, resets a scanning condition when overtaking the contrast medium, executes re-scanning under the reset scanning condition, and determines overtaking of the contrast medium based on differential data between measurement data acquired by non-contrast enhanced scanning to be performed before the main scanning and measurement data to be acquired by the main scanning. Hence, no image needs to be reconstructed during scanning to check whether or not there is a contrast effect, and the overtaking determination is performed at a high speed, which can swiftly shift to re-scanning.

Abstract translation: 为了提供即使在使用造影剂的扫描期间扫描位置超过造影剂的位置时，也可以获得具有良好对比度效果的图像而不重新注入造影剂的X射线CT装置和对比度增强扫描方法 ，则X射线CT装置判定在主扫描期间当前的扫描位置是否超过造影剂，当超过造影剂时复位扫描条件，在复位扫描条件下执行再扫描，并且确定造影剂的超驰 基于通过在主扫描之前执行的非对比度增强扫描获取的测量数据和通过主扫描获取的测量数据之间的差分数据。 因此，在扫描期间不需要重构图像以检查是否存在对比度效果，并且超速确定以高速执行，这可以迅速地转换到重新扫描。

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

IPC: G06T5/00 ,  G06T5/50 ,  A61B6/00 ,  A61B6/03 ,  A61B6/02

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：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

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

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.

公开(公告)号：US20170231589A1

公开(公告)日：2017-08-17

申请号：US15518933

申请日：2015-11-13

Applicant: HITACHI, LTD.

Inventor： Hideaki FUJII ,  Taiga GOTO ,  Tetsuo NAKAZAWA

IPC: A61B6/00 ,  A61B6/04 ,  A61B6/03

CPC classification number: A61B6/5205 ,  A61B6/032 ,  A61B6/0457 ,  A61B6/4452 ,  A61B6/461 ,  A61B6/469

Abstract: In a case where helical scanning, etc., is performed in an X-ray CT apparatus, upsampled projection data that more approximates to an observed value is obtained. There is provided an X-ray CT apparatus that improves spatial resolution of an overall effective field of view without reducing rotation speed, in an FFS method of acquiring projection data through moving of an X-ray focus position to a plurality of positions. The X-ray CT apparatus: converts projection data acquired through helical scanning into projection data of normal scanning performed by one rotation; generates a virtual-counter-data space in which virtual counter data are acquired on substantially coincident X-ray transmission path in the converted projection data; performs upsampling in a view direction; and similarly upsamples FFS projection data in the view direction for focus-shifted projection data obtained by performing the helical scanning while causing the X-ray focus position to shift (virtual counter data space generation).

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

IPC: A61B6/00 ,  A61B6/04 ,  A61B6/03

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.

公开(公告)号：US20170000442A1

公开(公告)日：2017-01-05

申请号：US15105329

申请日：2015-01-23

Applicant: HITACHI, LTD.

Inventor： Hisashi TAKAHASHI ,  Taiga GOTO ,  Koichi HIROKAWA

IPC: A61B6/00 ,  G06T7/00 ,  G06T11/00 ,  A61B6/03

CPC classification number: A61B6/5258 ,  A61B6/032 ,  A61B6/5205 ,  G01N23/046 ,  G06T7/0012 ,  G06T11/005 ,  G06T2207/10081

Abstract: In order to provide a technique capable of restoring measured data from projection data with high accuracy and removing system noise included in the measured data, a signal processing device obtains measured data x including signal values of 0 or less by processing an output signal from a data acquisition system, and performs a conversion process on the measured data x by using a predefined function including a logarithmic function so as to generate projection data (logarithmically converted data z), in which the predefined function is a function of which an inverse function is present for values of a predetermined negative number s or more, and the measured data x including signal values of 0 or less within a predetermined range is restored from the projection data by applying the inverse function to the projection data.

Abstract translation: 为了提供能够高精度地恢复来自投影数据的测量数据并且消除包括在测量数据中的系统噪声的技术，信号处理装置通过处理来自数据的输出信号来获得包括0或更小的信号值的测量数据x 并且通过使用包括对数函数的预定义函数对测量数据x执行转换处理，以便生成投影数据（对数转换数据z），其中预定函数是存在逆函数的函数 对于预定负数s以上的值，并且通过对投影数据应用逆函数，从投影数据中恢复包括在预定范围内的0或更小的信号值的测量数据x。