公开(公告)号：US20180011155A1

公开(公告)日：2018-01-11

申请号：US15547535

申请日：2016-02-15

Applicant: HITACHI, LTD.

Inventor： Kosuke ITO ,  Yoshihisa SOUTOME ,  Masahiro TAKIZAWA

IPC: G01R33/36 ,  G01R33/565 ,  G01R33/28

CPC classification number: G01R33/3607 ,  A61B5/055 ,  G01R33/246 ,  G01R33/288 ,  G01R33/5659

Abstract: In order to improve B1 non-homogeneity while reducing a local SAR in an object, particularly, in a human tissue during MR imaging, the present invention is characterized in that each of a plurality of irradiation channels is controlled on the basis of RF shimming parameters corresponding to the plurality of irradiation channels, and, in a case of performing imaging sequence of irradiating an object with an RF magnetic field, there is the use of the RF shimming parameters obtained by imposing a constraint condition on at least one of a plurality of principal components obtained through principal component analysis on the RF shimming parameters.

公开(公告)号：US20180028273A1

公开(公告)日：2018-02-01

申请号：US15614782

申请日：2017-06-06

Applicant: Hitachi, Ltd.

Inventor： Suguru YOKOSAWA ,  Yo TANIGUCHI ,  Hisaaki OCHI ,  Tomoki AMEMIYA ,  Yoshihisa SOUTOME

IPC: A61B90/00 ,  H04N19/105

CPC classification number: A61B90/37 ,  A61B5/055 ,  A61B2090/374 ,  G01R33/00 ,  G01R33/50 ,  G01R33/5608 ,  G01R33/561 ,  H04N19/105

Abstract: There is provided an MRI apparatus in which, when a quantitative value, which does not depend on imaging parameter values, is computed from a plurality of image data having different pixel values that are acquired by performing imaging the plurality of times with different imaging parameter values in the same pulse sequence, pixel values which are acquired from the imaging parameter values are predicted for each of a plurality of predetermined quantitative-value candidate group, and an initial value of the quantitative value is selected from the quantitative-value candidate groups with reference to the predicted pixel values. The optimal quantitative value is computed through a localized optimization technique using the selected initial value.

公开(公告)号：US20180085026A1

公开(公告)日：2018-03-29

申请号：US15701640

申请日：2017-09-12

Applicant: Hitachi, Ltd.

Inventor： Yukio KANEKO ,  Hisaaki OCHI ,  Yoshihisa SOUTOME

IPC: A61B5/053 ,  A61B5/055 ,  A61B5/00 ,  G01R33/24

CPC classification number: A61B5/0537 ,  A61B5/0536 ,  A61B5/055 ,  A61B5/7278 ,  A61B5/743 ,  G01R33/24 ,  G01R33/443

Abstract: When an electrical characteristic of a predetermined region of a subject placed in a static magnetic field space is measured by using magnetic resonance signals measured from the region, measurement data measured by coinciding direction of a tissue structure of the subject with the direction of the static magnetic field, and measurement data measured with a direction of the tissue structure of the subject crossing the direction of the static magnetic field are used. A rotating magnetic field map of the region is created from the measurement data, and the electrical characteristic is calculated by using the rotating magnetic field map. The electrical characteristic is calculated as an electrical characteristic including anisotropy by using information about the direction of tissue structure. According to the present invention, electrical characteristic such as electrical conductivity including anisotropy can be measured with good precision with an electrical characteristic measuring apparatus using nuclear magnetic resonance.

公开(公告)号：US20170146620A1

公开(公告)日：2017-05-25

申请号：US15318891

申请日：2015-06-23

Applicant: HITACHI, LTD.

Inventor： Hideta HABARA ,  Yoshihisa SOUTOME ,  Masahiro TAKIZAWA ,  Yoshiaki SATO

IPC: G01R33/28 ,  A61B5/055

CPC classification number: G01R33/288 ,  A61B5/055 ,  G01R33/3607

Abstract: Provided is a technique that enables accurate SAR management using power consumption by an object (Pobject) that was calculated based on accurately acquired Q-factors. For this purpose, the present invention calculates Q-factors of each channel of a high-frequency antenna using measurement results of amplitudes of forward waves and reflected waves of each high-frequency signal between three or more different frequencies. An existing SAR monitor in an MRI apparatus is used for the amplitude measurement. Also, the Q-factors are calculated based on a circuit coefficient to be acquired by fitting the measurement results to a predetermined circuit model. Then, the power consumption by an object (Pobject) is calculated using the calculated Q-factors in order to manage the SAR.

公开(公告)号：US20160135711A1

公开(公告)日：2016-05-19

申请号：US14897669

申请日：2014-06-23

Applicant: HITACHI, LTD.

Inventor： Masayoshi DOHATA ,  Yoshihisa SOUTOME

IPC: A61B5/055 ,  G01R33/34 ,  G01R33/36

CPC classification number: A61B5/0555 ,  G01R33/34084 ,  G01R33/3628 ,  G01R33/3664

Abstract: In a magnetic resonance imaging device provided with a deformable RF coil permanently mounted on a patient table, the RF coil can constantly maintain a matching state and a tuned state in a state of being flat on a top plate and in a state of being wound around a test object. Coil-side connectors 306-2 and 306-3 provided in a deformable RF coil 300 form a detector in cooperation with any one of fixture-side connectors 506-1 to 506-6, in which the detector detects a fitted state therebetween. A tuning circuit and a matching circuit of coil elements of the RF coil 300 are switched by an output of the detector to change tuning and matching parameters, and to maintain a matching state and a tuned state with respect to a state change indicating that the RF coil 300 is in a wound state.

Abstract translation: 在设置有可永久安装在患者台上的可变形RF线圈的磁共振成像装置中，RF线圈可以在顶板上处于平坦状态并且处于缠绕状态下可以恒定地保持匹配状态和调谐状态 一个测试对象。 设置在可变形RF线圈300中的线圈侧连接器306-2和306-3与固定装置侧连接器506-1至506-6中的任何一个配合形成检测器，其中检测器检测到它们之间的装配状态。 RF线圈300的线圈元件的调谐电路和匹配电路被检测器的输出切换，以改变调谐和匹配参数，并且相对于指示RF的状态变化保持匹配状态和调谐状态 线圈300处于缠绕状态。

公开(公告)号：US20150338492A1

公开(公告)日：2015-11-26

申请号：US14442168

申请日：2012-11-16

Applicant: HITACHI, LTD.

Inventor： Ryota SATO ,  Toru SHIRAI ,  Yo TANIGUCHI ,  Yoshihisa SOUTOME ,  Yoshitaka BITO

IPC: G01R33/565 ,  G01R33/48 ,  G01R33/50 ,  A61B5/055

CPC classification number: G01R33/56536 ,  A61B5/055 ,  A61B2576/00 ,  G01R33/4818 ,  G01R33/4828 ,  G01R33/50 ,  G01R33/5608 ,  G01R33/5613

Abstract: The estimation accuracy of a magnetic susceptibility value of tissue is improved by computing an edge image which represents the edge of the tissue on a magnetic susceptibility distribution and to reduce background noise without lowering the magnetic susceptibility value of the tissue. The present invention computes an absolute value image and a phase image from a complex image obtained by MRI, from the phase image, computes a low frequency region magnetic susceptibility image in which background noise is greater than a desired value, computes an edge information magnetic susceptibility image and computes a high frequency region magnetic susceptibility image, computes an edge mask from the edge information magnetic susceptibility image, smooths a magic angle region from the edge mask and the low frequency region magnetic susceptibility image and finally smooths a high frequency region using the high frequency region magnetic susceptibility image.

Abstract translation: 通过计算表示组织的磁化率分布的边缘的边缘图像并且降低背景噪声而不降低组织的磁化率值来提高组织的磁化率值的估计精度。 本发明从相位图像计算由MRI获得的复合图像中的绝对值图像和相位图像，计算背景噪声大于期望值的低频区域磁化率图像，计算边缘信息磁化率 图像并计算高频区磁化率图像，从边缘信息磁化率图像计算边缘掩模，从边缘掩模和低频区域磁化率图像平滑魔法角区域，并最终使用高频区域磁化率平滑高频区域 频域磁化率图像。