Hitachi, Ltd.

Hitachi Medical Corporation

Other

Hitachi Engineering Co., Ltd.

Hitachi Engineering Services Co., Ltd.

Nitto-denko Corporation

Hiroyuki Watanabe

Hirotaka Takeshima

Mitsushi Abe

Kenji Sakakibara

Yoshihide Wadayama

Tsutomu Yamamoto

Takeo Nemoto

Takao Honmei

Tomoo Chiba

Jun Kawamura

Takeshi Nakayama

Ryuya Ando

Masanori Takahashi

Hirofumi Motoshiromizu

Kunihito Suzuki

Hiroyuki Takeuchi

Michiya Okada

Kazuo Hiramoto

Kenji Miyata

Tsuyoshi Wakuda

Shigeru Kakugawa

Takeshi Yatsuo

Masatsugu Nishi

Akira Kurome

Junichi Hirota

Teruhiro Takizawa

Miki Yamazaki

Yoshio Hamadate

Shigeki Tounosu

Koichi Ikeda

Kunihiro Takayama

Hironori Tamai

Naoki Nakayama

Yasunori Koga

An electromagnet device which generates magnetic field in the direction perpendicular to the inserting direction of an inspection subject is reduced in size and weight by removing unnecessary arrangement as much as possible. A magnetic resonance imaging device is also provided. The electromagnet device comprises a first coil () through which a first circular current (J) circulates forward, a second coil () through which a second circular current (J) circulates reversely, and a coil group () through which a plurality of circular currents (J-J) circulate alternately forward and reversely. The first coil (), the second coil () and the coil group () are arranged in this order to increase the angle of elevation &#x3b8; (&#x3b8;1&#x3c;&#x3b8;2&#x3c;&#x3b8;3), and a blank region (S) not including the second coil () and the coil group () exists in the angular region between the angles of elevation &#x3b8;2 and &#x3b8;3.

Electromagnet devices compatible with magnetic resonance and MRI devices where circulating current directions alternate between coil groups separated by elevation angles between 26.25 and 55 degrees

Disclosed is a double-faced pressure-sensitive adhesive tape which includes a foam substrate, one pressure-sensitive adhesive layer arranged on or above one side of the substrate, and another pressure-sensitive adhesive layer arranged on or above the other side of the substrate. The adhesive tape has a total thickness of 250 &#x3bc;m or less. The adhesive tape is thin but highly waterproof (sealable against water). The adhesive tape preferably has a tensile strength of 0.5 to 20 MPa for further superior processability.

Double-faced pressure-sensitive adhesive tape

A superconducting magnet apparatus obtains high magnetic field uniformity without increasing the volume of a magnetic material even against disturbances. The superconducting magnet apparatus has a circular superconducting coil which generates a magnetic field; a coil vessel which contains the superconducting coiltogether with refrigerant; a thermal shield arranged so as to surround the coil vessel; a vacuum vessel with inside kept vacuum which surrounds the thermal-shield; and magnetic materials and for correcting the magnetic field, the magnetic materials being arranged in the vacuum vessel; wherein the magnetic materials and are supported by a heat-insulation support medium fixed to the coil vessel.

Superconducting magnet apparatus and magnetic resonance imaging apparatus

In a superconducting magnet, including a vacuum vessel, a coil vessel inside the vacuum vessel, and a superconducting coil inside the coil vessel for generating a magnetic field, has a magnetic member, disposed inside the vacuum vessel, supported with thermal insulation, for compensating the magnetic field; a heat exchange device disposed outside the vacuum vessel for supplying to or absorbing heat from the vacuum vessel; and thermal conducting members thermally connecting the heat exchange device via the vacuum vessel to the magnetic member. An MRI including the superconducting magnet is also disclosed.

Superconducting magnet and magnetic resonance imaging apparatus

A superconducting magnet includes: first and second torus coolant containers substantially symmetrically, vertically arranged to have a space and a symmetrical plane therebetween for storing a coolant. Each of the first and second torus coolant containers includes therein a main coil bobbin with a main coil for generating a measurement magnetic field, a shield coil bobbin with a shield coil for generating a shielding magnetic field for suppressing outside leak of the measurement magnetic field, a plate member vertically reinforced at a plane thereof opposite to a plane thereof facing the symmetrical plane for supporting the shield coil bobbin and the main coil bobbin. The main coil bobbin is further supported by the shield coil bobbin, to cause the main coil to generate the measurement magnetic field having a substantially uniform magnetic field intensity at a middle region of the space. A magnetic resonance imaging apparatus using the superconducting magnet is also disclosed.

Superconducting magnet and magnetic resonance imaging apparatus using the same

A super-conducting magnet apparatus in an MRI system which may reduce unevenness among magnetization characteristics of ferromagnetic elements arranged between super-conductive shield coils and superconducting main coils. There are provided a pair of super-conducting main coils, a pair of superconductive shield coils arranged on the axes of the pair of super-conducting main coils, being spaced from the pair of super-conducting main coils, and also arranged on opposite sides of a zone to be observed, and ferromagnetic elements arranged in parts of spaces extending from air core parts of the super-conducting main coils to air core parts of the super-conductive shield coils. The super-conductive shield coils have an outer diameter which is larger than that of the super-conducting main coils. The ferromagnetic elements are composed of a plurality of axially symmetric ferromagnetic members which are coaxially arranged, and which have a space in at least a radial part thereof, but not in a center axis part. With this configuration, the magnetic saturation of the ferromagnetic members may be facilitated. Thereby it is possible to reduce the effect of unevenness among magnetization characteristics of the ferromagnetic elements.

Superconductive magnetic apparatus for magnetic resonance imaging unit

A cryostat is formed into a donut form, where a cylindrical or a square concave is formed in the center of the cryostat of the superconductive magnet apparatus for an open type MRI apparatus, and the cryo-compressor is disposed in the concave.

Superconductive magnet apparatus and magnetic resonance imaging apparatus

An object of the present invention is to provide a MRI superconductive magnet enables sharp images representing patients' health states to be produced. [Means for Achieving the Object] A MRI superconductive magnet having a superconductive coil, a liquid vessel of liquid helium used to cool the superconductive coil, a heat shield to accommodate the liquid vessel therein, a vacuum chamber to accommodate the heat shield therein, a load supporting body for supporting the superconductive coil from the vacuum chamber and securing the superconductive coil, a second cold part of a multi-stage refrigerator for cooling a heat exchanger to condense evaporated helium gas, and a first cold part of the multi-stage refrigerator for cooling the heat shield, wherein a magnetic shield is provided from the first cold part of the multi-stage refrigerator to an outer periphery of the second cold part of the multi-stage refrigerator.

MRI superconductive magnet

An MRI apparatus having a configuration that reduces vibration of a static magnetic field generating source is provided. A closed vesselof the static magnetic field generating source is provided with a rigid structurefor preventing transmission of vibration generated from a gradient magnetic field generating partto other members via the closed vessel. The rigid structureuses, for example, a connecting partthat connects a faceon the imaging space side and a faceconfronting it. The rigidity of the closed vessel is thereby increased, and therefore vibration transmitted from the gradient magnetic field generating part can be reduced. The connecting part can have a through-hole structure, and in such a case, internal space of through-hole can be used for drawing cables.

Magnetic resonance imaging device

A magnetic resonance imaging apparatus and the magnet apparatus thereof comprise plural pairs of magnetic field generation sources, arranged face to face with each other, for forming a magnetic field space; and magnetic field homogeneity adjusting apparatusesandfor providing homogeneity adjustment of the magnetic field formed in the magnetic field space. The magnetic field homogeneity adjusting apparatusesandcontain a plurality of tapped holesfor installing a magnetic field homogeneity adjusting memberof smaller volume in a plate-formed tray made of a non-magnetic substance; and a plurality of mountsfor installing the magnetic field homogeneity adjusting memberof greater volume, these mounts being formed over the area containing a plurality of through-holes for permitting installation of a magnetic field homogeneity adjusting memberof smaller volume, whereby major magnetic field adjusting work can be performed independently of minor magnetic field adjusting work.

Magnetic resonance imaging apparatus and magnet apparatus therefor

An MRI apparatus includes magnet members for compensating the magnetic field which are disposed to a thermal shield system of the superconducting apparatus. The magnet members for compensating the magnetic field are disposed at positions where temperature change in the vacuum chamber is not transferred to the interior of the vacuum chamber.

Superconducting magnet apparatus and magnetic resonance imaging apparatus using the same

The MRI apparatus has ring-shaped superconducting coils arranged to vertically oppose each other. The superconducting coils are installed in ring-shaped cooling containers. The cooling containers are accommodated in radiation shield plates. The radiation shield plates are accommodated in vacuum vessels. The cooling containers are connected together at at least two locations. Support members are arranged between an outer wall surface of the lower cooling container and an inner wall surface of the lower vacuum vessel to support the lower cooling container on the lower vacuum vessel. The upper cooling container is free, supported only by the connecting tubes connecting the upper and lower cooling containers.

Magnetic resonance imaging apparatus

The invention utilizes a characteristic of superconducting coils that they have high thermal conductivity in a direction of winding. A part of the superconducting coils is thermally connected with liquid helium through thermal anchors so that the part of the superconducting coils can be cooled to the liquid helium temperature. This cooling structure maintains thermal stability of a superconducting MRI magnet even in a condition that a refrigerator stops for a certain period of time, and reduces a manufacturing cost of the superconducting magnet.

Superconducting magnet for MRI

A magnet for MRI apparatus has a magnetic circuit which includes a magnetic flux path formed by a ferromagnetic material and a magnetic flux path formed by magnetic flux return coils or magnetic flux control coils, so that a 5-gauss line of leakage fluxes can be kept within a sphere 3 m in radius even when the static magnetic field intensity exceeds 1 tesla and a comparatively light magnet for MRI apparatus can be provided. Further, the fluxes escaping vertically from the static magnetic field sources are led compactly to a horizontal direction by installing magnetic flux paths of ferromagnetic materials and coils with polarities opposing those of the static magnetic fields. This arrangement minimizes an increase in the total height of the magnet for MRI apparatus, keeping the magnet within the total height of 3 m.

Magnet for magnetic resonance imaging apparatus

In a super conductive magnet apparatus comprising a super conductive coil, a helium containing volume for containing therein liquid helium to keep a temperature of the super conductive coil low, and a vacuum vessel containing therein the super conductive coil and the helium containing volume, the super conductive magnet apparatus further comprises a support body on which the super conductive coil is arranged, a container cover forming the helium containing volume with the support body in such a manner that a thermal energy is capable of being transmitted between the super conductive coil and the liquid helium, and a connecting member connecting the support body to the vacuum vessel so that the support body is supported through the connecting member on the vacuum vessel.

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Hitachi, Japan

Hiroyuki Watanabe