Hitachi, Ltd.

Hitachi Medical Corporation

Yoshihisa Soutome

Yoshitaka Bito

Hideta Habara

Hisaaki Ochi

Hiroyuki Takeuchi

Yosuke Otake

Tetsuhiko Takahashi

Yo Taniguchi

Yukio Kaneko

Toru Shirai

Masayoshi Dohata

Koji Hirata

Ryota Sato

Satoshi Hirata

Masahiro Takizawa

Suguru Yokosawa

Yoshiaki Sato

Kosuke Ito

Hiroyuki Itagaki

Takeshi Yatsuo

Shinichiro Suzuki

Tomoki Amemiya

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.

Magnetic resonance imaging apparatus and quantitative-value computing program

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-and-provided in a deformable RF coilform a detector in cooperation with any one of fixture-side connectors-to-, in which the detector detects a fitted state therebetween. A tuning circuit and a matching circuit of coil elements of the RF coilare 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 coilis in a wound state.

Magnetic resonance imaging device and RF coil assembly with matching switch circuit and tuning switch circuit

With an MRI apparatus using a transmission coil having multiple channels, a region desired to be diagnosed is efficiently imaged with high image quality. The MRI apparatus comprises a region setting means for setting a region in an imaging region, of which high quality image is desired to be obtained, as a first region, and an optimization means for determining at least one of amplitude and phase of a radio frequency wave transmitted to each of the multiple channels as a radio frequency magnetic field condition, and the optimization means determines the radio frequency magnetic field condition so that at least one of specific absorption ratio and signal value of a region that generates artifacts is not higher than a predetermined value defined for each, under a uniformity constraint condition that uniformity of radio frequency magnetic field distribution in the first region is not lower than a predetermined value.

Magnetic resonance imaging device, and determination method for high-frequency magnetic field conditions

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.

Magnetic resonance imaging apparatus and method for setting RF shimming parameters

A technique in a medical imaging apparatus being capable of setting any plane in three-dimensional space as an imaging slice is provided, allowing an automatically-set imaging slice to be configured to suit user's preferences, and determine a position of the imaging slice being configured, with respect to an imaging target subject automatically with a high degree of accuracy. Reference information for specifying the imaging slice, set by the user for each imaging site, is associated with the anatomical feature of the imaging site, so as to generate an imaging slice parameter. Upon actual imaging, the imaging slice parameter and the anatomical feature of the imaging target subject obtained by scout imaging are used to determine the imaging slice position of the imaging target subject.

Medical image imaging device for positioning an imaging slice

Provided is a technique capable of achieving safety and image quality at the same time in an MRI device using a transmission coil including plural channels. An SAR distribution is calculated, and an imaging parameter is determined for optimizing a radio frequency magnetic field distribution in an imaging region while suppressing a maximum value of an SAR to be equal to or smaller than a predetermined threshold value. The determined imaging parameter includes a radio frequency magnetic field parameter for specifying radio frequency pulses to be transmitted through each of the plural channels. The SAR distribution is calculated using a database that retains an electric field distribution of each of the plural channels for each subject model retained in advance.

Magnetic resonance imaging device and imaging parameter determination method

Provided is a technique that enables accurate SAR management using power consumption by an object (P) 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 (P) is calculated using the calculated Q-factors in order to manage the SAR.

Magnetic resonance imaging apparatus, Q-value calculation method, and specific absorption rate management method

A magnetic resonance imaging apparatus comprising a measurement parameter-setting unit for setting measurement parameters that determine the strength and timing of the high frequency magnetic field and the gradient magnetic field, and a measuring unit for applying the high frequency magnetic field and the gradient magnetic field on a subject placed in the static magnetic field according to the measurement parameters and detecting the nuclear magnetic resonance signal generated from the subject as a complex signal. The measurement parameter-setting unit is equipped with: a basic parameter-inputting section for setting the imaging parameters and imaging cross-section; a limiting condition-inputting section for setting limiting conditions that apply limits on the setting of the voxel size; a voxel size-calculating section for setting the voxel size according to the limiting conditions; and a voxel size-displaying section for displaying the set voxel size to the user.

Magnetic resonance imaging apparatus with voxel size control based on imaging parameters and magnetic susceptibility

Provided is an antenna such as a TEM-type antenna and a microstrip-type antenna that has rung conductors and a shield conductor to electrically connect and use them. A holding member that maintains a shape of the shield conductor is composed by assembling ribs and thin walls. An inner holding member is a structural material. Holes are provided on at least either one of the shield conductor and the holding member adhered thereto or the inner holding member, which can adjoin conductors from the outside of the cylindrical antenna through the said holes during the antenna production.

Magnetic resonance imaging apparatus and antenna device

There is provided a technique for obtaining temperature information for inside of a living body and accuracy information thereof in short time with low burden imposed on a subject. It is realized with a spectrum calculator configured to perform MRS or MRSI measurement for two kinds of substances showing difference of resonant frequencies and calculating spectra of magnetic resonance signals of the two kinds of substances, a temperature information calculator configured to calculate temperature information for inside of the subject on the basis of peaks of the calculated spectra, a temperature accuracy information calculator configured to calculate temperature accuracy information indicating accuracy of the temperature information on the basis of peaks of the calculated spectra, and a display information generator configured to generate display information to be displayed on a display device on the basis of the temperature information and the temperature accuracy information.

Magnetic resonance imaging apparatus

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.

Magnetic resonance imaging device and quantitative susceptibility mapping method

Systems and methods for magnetic resonance imaging, including adjusting spatial distribution of a rotating magnetic field. By minimizing imaging time, the Bnonuniformity reducing effect of RF shimming is maximized for an imaging section of an arbitrary axis direction and an arbitrary position. Bdistributions are measured for only several sections of one predetermined direction, and a radio frequency magnetic field condition that maximizes the Bnon-uniformity reducing effect for an imaging section of an arbitrary direction and an arbitrary position is calculated from the Bdistribution data.

Magnetic resonance imaging equipment, high frequency magnetic field irradiation method and program

In order to provide a technique which can suppress coupling to homogenize the spatial distribution of an RF magnetic field and can improve penetration of the RF magnetic field into the subject, pad-like electric field conductors having a predetermined area are provided outside both ends of a rung conductor as a part of a configuration which forms a loop-like circuit and is driven as an antenna. An antenna device includes a sheet-like conductor, a rung conductor which is arranged at a predetermined distance from the sheet-like conductor, two electric field conductors which are arranged in both end portions of the rung conductor at a predetermined distance from the sheet-like conductor, and connection terminals which are transmission and reception terminals provided in the rung conductor and the sheet-like conductor. The rung conductor and the sheet-like conductor configure a loop circuit which resonates at a preset frequency.

An object of the present invention is to suppress artifacts generated by correction of spectral distortion induced by eddy currents in MRI devices with a simple method, and thereby improve accuracy of the correction.

Magnetic resonance imaging device, phase value correction method and program

A lower cost MRI device with a portable table detachable from the gantry is provided along with a lower cost table equipped with an easy-to-use and easy-to-install RF coil system able to perform high-resolution head and neck imaging and high-speed whole body imaging in both head-first and feet-first modes. This magnetic resonance imaging device has a portable table detachable from the gantry, and the portable table has a docking connector that can be connected to the gantry and a ceiling panel on which an RF coil can be installed to receive nuclear magnetic resonance signals generated by the examinee and to irradiate the examinee with a high-frequency magnetic field. The RF coil is divided into two or more RF coil units, the ceiling panel has a plurality of ceiling panel connectors enabling each RF coil unit to be connected, and each RF coil unit has a connector. Each RF coil unit is arranged in overlapping fashion on the ceiling plate and the ceiling panel connectors and coil connectors are connected without having to establish an electrical connection between RF coil units.

Growing community of inventors

Tokyo, Japan

Yoshihisa Soutome