Hitachi, Ltd.

Fujifilm Healthcare Corporation

Hitachi Medical Corporation

Yosuke Otake

Hisaaki Ochi

Yoshitaka Bito

Yoshihisa Soutome

Kohjiro Iwasawa

Hideta Habara

Koji Hirata

Yukio Kaneko

Toru Shirai

Kazuyuki Kato

Shinichiro Suzuki

Hiroyuki Takeuchi

Tetsuhiko Takahashi

Satoshi Yamashita

Satoshi Hirata

Hikaru Hanada

Masayoshi Dohata

Ryota Sato

Takanori Nishiyama

Takahide Shimoda

Provided is a coil device capable of improving operability or durability thereof, being attached to a subject in a close contact state regardless of the size of a head of the subject, and obtaining a high-quality MRI image. The coil device includes at least one coil unit which has a coil element and a coil support portion which has a mechanism for attaching the coil unit to a head of a subject. The coil support portion includes a base portion, a support body which is connected to the base portion and has an elastic member, and a holder which connects the support body to the at least one coil unit and the holder has at least three contact points which are formed directly or indirectly with respect to the base portion.

Head coil device and magnetic resonance imaging apparatus using the same

The receiving coil device includes one or a plurality of receiving coils configured to cover a head of a subject, a base portion on which the head of the subject is to be placed, a holder portion supported by the base portion, one of the receiving coils being fixed to the holder portion, a mechanism portion configured to bring the receiving coil fixed to the holder portion into close contact with a part of the head, and further, a detection unit configured to detect a physical quantity related to a displacement of the holder portion on the holder portion or the base portion. The physical quantity detected by the detection unit is sent to an MRI apparatus including the receiving coil device.

Receiving coil device and magnetic resonance imaging apparatus including the same

A high-frequency array coil for an MRI apparatus includes: a plurality of coil units each of which includes a plurality of RF reception coils including a conductor loop and adjusted to receive a magnetic resonance signal; an extension conductor which includes a part of each conductor loop of each RF reception coil of the plurality of coil units and a conductor connecting the parts; and an extension conductor control circuit which adjusts a reception frequency of the extension conductor. The extension conductor is disposed so as to be wound in a spiral shape when the extension conductor is disposed on a subject and a direction of a magnetic field to be detected intersects a direction of a magnetic field detected by the RF reception coil constituting the coil unit. Accordingly, the detection efficiency of an RF coil can be increased and an image with a high SNR can be obtained.

Array coil and magnetic resonance imaging apparatus

A flexible RF coil with excellent portability is provided. The RF coil includes a first coil, a first skeleton, and a second skeleton, the first skeleton and the second skeleton being rod shaped. The first coil includes a first loop made from a conductor that receives radio frequency signals, and a first signal detector that is inserted in series into the first loop and that detects the signals received by the first loop. The first skeleton and the second skeleton are arranged with a spacing in the short axis direction, the first signal detector is mounted on the first skeleton, and a portion of the first loop that faces the first signal detector is mounted on the second skeleton. The first loop is deformable, and the spacing between the first skeleton and the second skeleton is changeable in accordance with the deformation of the first loop.

Radio frequency coil and magnetic resonance imaging apparatus using the same

An MRI image with high image quality can be acquired regardless of a size of an examinee. An array coil includes: a coil unit in which a plurality of sub-coils which includes a loop coil portion in which a conductor having flexibility with a predetermined length is curved and which is adjusted to receive a magnetic resonance signal from an examinee are arranged at predetermined intervals; and a coil casing that is formed of a sheet-shaped material which expands and contracts in at least one direction and accommodates the coil unit therein. At least one position of each of the plurality of sub-coils is fixed to the coil casing and an inter-center distance between the sub-coils varies with expansion and contraction of the coil casing.

A multichannel array coil of an MRI apparatus achieves both a wide sensitivity and low noise. An RF coil (array coil) is provided with a plurality of subcoils. Each of those subcoils is adjusted to be receivable of nuclear magnetic resonance signals, and also adjusted so that a part of current (first current) passing through one subcoil upon receipt of the signals flows into the other subcoil in the form of sub-current. A flowing direction of the first current is opposite to the flowing direction of the sub-current, and an electric field generated by the first current within a subject and an electric field generated by the first sub-current within the subject intensify each other in the space between a first loop coil unit and a second loop coil unit. Accordingly, noise correlation that is determined by an inner product of the electric fields is reduced, thereby achieving low noise.

Radio frequency coil, magnetic resonance imaging device using same, and method for adjusting multi-channel radio frequency coil

A technique for reconciling large sensitivity area and high sensitivity for deep part in a multi-channel array coil of an MRI apparatus without complicating the configuration, and realizing both higher speed imaging and high image quality is provided. An RF coil (array coil) of a magnetic resonance imaging apparatus comprising a plurality of subcoils is provided. At least one of the subcoils is a first subcoil of which resonance frequency as that of the subcoil alone differs from magnetic resonance frequency. The first subcoil is adjusted so that it magnetically couples with a second subcoil, which is at least one other subcoil, and thus resonates at the same frequency as the magnetic resonance frequency. Input and output terminals of the first subcoil and the second subcoil are connected to different low input and output impedance signal processing circuits, respectively.

High frequency coil and magnetic resonance image pickup device

In a multi-channel array coil used as an RF coil of an MRI apparatus, even when magnetic coupling occurs between the respective sub-coils, it is possible to suppress the influence of a current flowing through the sub-coil of a coupling counterpart to maintain the desired sensitivity and suppress deterioration of image quality. Therefor, even when magnetic coupling occurs between sub-coils constituting the multi-channel array coil used as the RF coil of the MRI apparatus, the sub-coils are connected to a signal processing circuit so that a phase difference between a rotating magnetic field generated by the influence of a current flowing through the sub-coil of the coupling counterpart and a rotating magnetic field generated by the sub-coil is less than 90 degrees.

High frequency coil and magnetic resonance imaging device

In order to provide a technique in which, in the TEM type antenna, the uniformity of sensitivity in the internal portion of the antenna can be maintained with simple configuration, without scarifying the internal space of the antenna, regardless of a size, a shape and a location of a load, and also regardless of locations of the constitutional members of the antenna, the TEM type antenna includes rung conductors which branch out into plural pieces in the middle portion and join into one piece in the two end portions. In other words, the rung conductor having a void space in the middle portion of the rung conductor in the longitudinal direction is provided. The adjacent rung conductors are disposed to be further closer to each other in the middle portion, and to maintain the same distance as that in the related art in the end portion.

Magnetic resonance imaging apparatus and antenna device

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.

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

To provide a technique for sufficiently eliminating magnetic coupling between RF coils and improving image quality when a multi-element multi-tuned RF coil is used as a receive RF coil for an MRI device. In the invention, each of RF coils which constitute a multi-element multi-tuned RF coil which is used as a receive RF coil for an MRI device is provided with an inter-coil magnetic coupling prevention circuit which resonates at each frequency to which each RF coil is tuned and provides a high impedance. The inter-coil magnetic coupling prevention circuit adjusts an inductor and a capacitor so that both of a circuit on the side of a pre-amplifier viewed from both ends of a signal reception circuit and a circuit on the side of the signal reception circuit viewed from both ends of a serial resonance circuit connected to the pre-amplifier resonate at a plurality of frequencies to which the respective RF coils are tuned.

RF coil and magnetic resonance imaging device

There is provided a technique for improving quality of images obtained with an MRI apparatus by using the geometric structures of the conventional RF transmission coil and RF reception coil and without increasing burden on patients or MRI technicians. A conductor loop of an RF reception coil disposed between a subject and an RF transmission coil is used also as a loop for magnetic field adjustment in order to shield or enhance a rotating magnetic field Bgenerated by the RF transmission coil. Further, the conductor loop operated as a conductor loop for magnetic field adjustment among the conductor loops constituting the RF reception coil is driven so that inhomogeneity of the rotating magnetic field Bis reduced.

RF reception coil and magnetic resonance imaging apparatus using same

In the diffusion spectroscopic imaging, in which intensity of molecular diffusion is imaged with separating chemical substances, with suppressing artifacts resulting from object motion of an object, spatial resolution, spectral band and SNR are maintained, and measurement accuracy is enhanced. A measurement for acquiring diffusion SI data is repeated a plurality of times with changing acquisition timing, phase variation of each measurement result is corrected, and a diffusion SI image is reconstructed from the corrected measurement results. In addition, the phase variation is calculated for every point in the space from the diffusion SI data acquired by each measurement or navigation data obtained by each measurement. The phase correction is independently performed for every point in the space.

Magnetic resonance device with diffusion gradient phase variation positionally corrected

The present invention provides a technique for maintaining a function for effectively blocking common mode noise with a simple configuration, even in the case where unbalance occurs in characteristic impedance of a coaxial cable in an MRI apparatus, and improving the performance of an RF coil. In a circuit where a balun is established by parallel connection with the coaxial cable, multiple serial resonance circuits having different resonance frequencies are connected in parallel. A value of each constitutional element of each of the serial resonance circuits is adjusted in such a manner that the frequency for blocking the common mode noise of the entire balun falls into a range between the resonance frequencies of these serial resonance circuits.

Growing community of inventors

Tokyo, Japan

Yosuke Otake