Hitachi Medical Corporation

Sumitomo Special Metals Co., Ltd.

Hitoshi Yoshino

Hiroyuki Takeuchi

Tsuneo Maeda

Masakatsu Iwasaki

Munetaka Tsuda

Masaaki Aoki

Yoshiaki Amano

Isamu Takekoshi

Shigeo Hashimoto

Seiji Kamimura

Hiroshi Nishimura

Tsuyoshi Tsuzaki

Shouichi Miyawaki

Ryosuke Fukami

Masahiro Iizuka

Fred Goldie

Masayuki Nakatsu

A nuclear magnetic resonance diagnosing apparatus for continuously taking tomograms in a space formed between a pair of magnets includes a cylindrical table top support of a gantry side, a pair of magnets vertically arranged, a table top support of the gantry side being interposed between the pair of magnets; and a column for supporting at least the magnet arranged in an upper side between the pair of magnets. The column is formed so that between a gantry and an examining table body, a width between a bridge construction, which is provided between the column and the table top support of the gantry side, and the table top support of the gantry side may be smaller than an examination width L determined by lines R' passing through a center of the table top support of the gantry side perpendicular to a center line R.

Nuclear magnetic resonance diagnosing device and diagnosing system

In a superconductive magnet device comprising upper and lower vacuum vessels coupled by a coupling conduit, the upper and lower vacuum vesselsand the coupling conduitcoupling them are made of a high electric-resistance material so that the magnetic flux of gradient magnetic field coils reaches the upper and lower pair of a second heat shieldsand a coupling conduitcoupling the pair of the second heat shieldsThe coupling conduitcoupling the upper and lower pair of the second heat shieldsis provided with a slit (cut)extending in the vertical direction so that no eddy currents occur and thus eddy currents generated asymmetrically in the coupling conduitare reduced. Artifacts caused by asymmetrical eddy currents can by reduced in an MRI apparatus using such a magnet device.

Open magnet device and magnetic resonance imaging apparatus comprising it

An MRI apparatus having an open structure includes a static magnetic field generating magnet including magnetic field generating sources arranged above and below an imaging space and magnetic field fluctuation reducing plates arranged inside the magnet. Gradient magnetic field coils are fixed to the static magnetic field generating magnet so as to not be in contact with the magnetic field fluctuation reducing plates. When the strength of the magnetic field generated by the static magnetic field generating magnet fluctuates due to vibration of the gradient magnetic field coils or other devices during an imaging operation of the MRI apparatus, an eddy current is generated on the magnetic field fluctuation reducing plates in response to the magnetic field fluctuation components. Magnetic flux which cancels the static magnetic field fluctuation components is generated due to this eddy current, and consequently, a time-sequentially stable static magnetic field can be obtained.

MRI apparatus correcting vibratory static magnetic field fluctuations, by utilizing the static magnetic fluctuation itself

Magnetic resonance imaging apparatus

A magnetic resonance imaging apparatus configured using a single column for supporting magnet devices disposed above and below the apparatus, wherein peripheries of yokes covering the magnet devices are formed to be arcs, thereby improving openness and accessibility of an operator to an object under examination.

Magnetic field generating device for use in MRI

A gradient magnetic field generation apparatus for generating a gradient magnetic field in a space in which an inspection object is placed includes at least one gradient magnetic field coil and a retaining member of the coil which undergoes deformation vibration by an electromagnetic force generated when a current is caused to flow through the coil. This apparatus generates noise and vibration whenever a pulse current is applied to the coil, because an electromagnetic force develops in the coil due to the pulse current and the coil as well as the retaining member of the coil undergo deformation and vibration. Therefore, a force which inhibits this deformation and vibration is applied to the retaining member so as to prevent deformation and vibration of the coil and the retaining member and to keep their shapes constant. In a preferred embodiment, a piezoelectric device is fixed to the retaining member without damping, and the force for inhibiting deformation and vibration of the retaining member is applied by controlling a voltage applied to the piezoelectric device.

Quiet magnetic resonance imaging apparatus

A magnetic field generating apparatus has a permanent magnet arrangement for generating a magnetic field in a magnetic field generating space and a yoke arrangement for forming magnetic circuits for generation of the magnetic field together with the permanent magnet arrangement. The yoke arrangement includes a first pair of yokes arranged facing each other, a second pair of yokes arranged facing each other through which the first pair of yokes are magnetically connected to each other, a third pair of yokes arranged between one end of one of the first pair of yokes and one end of one of the second pair of yokes and between the other end of the one of the first pair of yokes and one end of the other of the second pair of yokes, respectively, and yoke moving units for independently moving the one of the first pair of yokes and each of the second pair of yokes with respect to the third pair of yokes, respectively.

Magnetic field generating apparatus

A signal receiving coil device for an MRI apparatus, to be fitted to a patient for detecting nuclear magnetic resonance signals, comprising a coil member assuming a substantially cylindrical shape when fitted to the patient and having at least one flexible section and at least one rigid section disposed sequentially and alternately in a circumferential direction of said cylindrical shape; a first coil unit disposed on the coil holding member, and having a signal receiving direction thereof crossing substantially orthogonally the direction of a static magnetic field generated by the MRI apparatus when the coil holding member is fitted to the patient; and a second coil system disposed on the coil holding member, and having a signal receiving direction of reception thereof crossing substantially orthogonally both of the direction of the static magnetic field and the signal receiving direction of the first coil unit when the coil holding member is fitted to the patient.

Signal receiving coil device for MRI apparatus

RF coils for a nuclear magnetic resonance device having following features separated or combined at an intersecting portion of two conductive loops disposed so that sensitive directions thereof are substantially perpendicular to a direction of a static magnetic field and that the conductive loops intersect each other with a predetermined interval; (1) conductors of conductive loops are narrowed; (2) neighborhood of intersecting portion is grounded; and (3) a member having a small dielectric constant is put inside of an intersecting portion.

Growing community of inventors

Kashiwa, Japan

Hitoshi Yoshino