Abstract: Provided are a magnetic resonance imaging device and a superconducting magnet capable of preventing generation of eddy currents accompanying vibration of a radiation shield and of reducing image quality deterioration. The superconducting magnet for a magnetic resonance imaging device includes a substantially cylindrical vacuum vessel, a substantially cylindrical radiation shield that is provided inside the vacuum vessel, and a superconducting coil that is provided inside the radiation shield. The radiation shield has an inner cylinder located radially inward of the superconducting coil. The inner cylinder of the radiation shield is provided with an annular rib formed in a circumferential direction about the central axis of the inner cylinder.

Abstract: According to one embodiment, a magnetic resonance imaging apparatus includes: a cylindrical magnetic pole for generating a static magnetic field in an imaging region; a cylindrical gradient magnetic field coil arranged on a radially inner side of the magnetic pole, coaxially with the magnetic pole to generate a dynamic magnetic field having a linear magnetic field strength in the imaging region; a cylindrical high frequency coil arranged on a radially inner side of the gradient magnetic field coil, coaxially with the magnetic pole and the gradient magnetic field coil to generate a high frequency magnetic field in the imaging region; and a computer system for processing signals to obtain images. The magnetic resonance imaging apparatus further includes at least two loop-shaped additional coils arranged on the radially outer side of the gradient magnetic field coil and having different electric current circulating direction.

Abstract: Provided are a magnetic resonance imaging device and a superconducting magnet capable of preventing generation of eddy currents accompanying vibration of a radiation shield and of reducing image quality deterioration. The superconducting magnet for a magnetic resonance imaging device includes a substantially cylindrical vacuum vessel, a substantially cylindrical radiation shield that is provided inside the vacuum vessel, and a superconducting coil that is provided inside the radiation shield. The radiation shield has an inner cylinder located radially inward of the superconducting coil. The inner cylinder of the radiation shield is provided with an annular rib formed in a circumferential direction about the central axis of the inner cylinder.

Abstract: According to one embodiment, a magnetic resonance imaging apparatus includes: a cylindrical magnetic pole for generating a static magnetic field in an imaging region; a cylindrical gradient magnetic field coil arranged on a radially inner side of the magnetic pole, coaxially with the magnetic pole to generate a dynamic magnetic field having a linear magnetic field strength in the imaging region; a cylindrical high frequency coil arranged on a radially inner side of the gradient magnetic field coil, coaxially with the magnetic pole and the gradient magnetic field coil to generate a high frequency magnetic field in the imaging region; and a computer system for processing signals to obtain images. The magnetic resonance imaging apparatus further includes at least two loop-shaped additional coils arranged on the radially outer side of the gradient magnetic field coil and having different electric current circulating direction.

Abstract: A gradient magnetic field coil device has a main coil arrangement formed by embedding into first resin multiple main coils for generating a gradient magnetic field and a leakage magnetic field, and a shield coil arrangement formed by embedding into second resin multiple shield coils for suppressing the leakage magnetic field, wherein the shield coil arrangement includes a facing area that faces the main coil arrangement and is fixed to the main coil arrangement, and a protruding area that protrudes beyond the main coil arrangement, wherein insulated reinforcing members are embedded into the second resin in the protruding area. Multiple reinforcing members are arranged in a circumferential direction of the shield coil arrangement, and the second resin is preferably filled between the adjacent-to-each-other reinforcing members. The reinforcing members are preferably arranged toward the main coil arrangement with respect to the shield coils.

Abstract: A gradient magnetic field coil device is provided in which an eddy current magnetic field of an even-ordered component can be reduced. The gradient magnetic field coil device includes a forward coil and a reverse coil which faces the forward coil so as to sandwich a middle surface and through which flows an electric current directed opposite to the forward coil. The forward coil and the reverse coil have a middle region approaching the middle surface and an outside-the-middle region where the distance from the middle surface is greater than the middle region. A line width of coil lines in the middle region is narrower than a line width of coil lines in the outside-the-middle region.

Abstract: A gradient coil device includes a major axis gradient coil, having an ellipse in a cross section generating a gradient magnetic field inclined in a major axis direction of the ellipse at a magnetic field space; and a minor axis gradient coil, having an ellipse in a cross section generating a gradient magnetic field inclined in a minor axis direction of the ellipse at the magnetic field space. A length of the minor axis field coil in the center axis direction is shorter than a length of the major axis gradient coil in the center axis direction. A maximum value of a residual magnetic field generated by the minor axis gradient coil at a space outside the magnetic field space is equal to or smaller than a maximum value of a residual magnetic field generated by the major axis gradient coil at a space outside the magnetic field space.

Abstract: A gradient magnetic field coil device has a main coil arrangement formed by embedding into first resin multiple main coils for generating a gradient magnetic field and a leakage magnetic field, and a shield coil arrangement formed by embedding into second resin multiple shield coils for suppressing the leakage magnetic field, wherein the shield coil arrangement includes a facing area that faces the main coil arrangement and is fixed to the main coil arrangement, and a protruding area that protrudes beyond the main coil arrangement, wherein insulated reinforcing members are embedded into the second resin in the protruding area. Multiple reinforcing members are arranged in a circumferential direction of the shield coil arrangement, and the second resin is preferably filled between the adjacent-to-each-other reinforcing members. The reinforcing members are preferably arranged toward the main coil arrangement with respect to the shield coils.

Abstract: In the magnetic resonance imaging device, the distance between the first and second coils is different in the circumferential direction and has a first region (A1) (?=0, ?) and a second region (A2) (?=?/2) narrower than the first region (A1). In the first coil, wiring patterns (17a, 17b) on the side of a zero-plane (F0) passing through the center of the first coil and perpendicular to the axis direction (z-axis direction) meander in the circumferential direction such that the wiring patterns (17a, 17b) depart from the zero-plane (F0) in the first region (A1) and approach the zero-plane (F0) in the second region (A2). This provides a gradient magnetic field coil capable of configuring wiring patterns without using a loop coil that does not pass through the z-axis.

Abstract: A gradient magnetic field coil device is provided in which an eddy current magnetic field of an even-ordered component can be reduced. The gradient magnetic field coil device includes a forward coil and a reverse coil which faces the forward coil so as to sandwich a middle surface and through which flows an electric current directed opposite to the forward coil. The forward coil and the reverse coil have a middle region approaching the middle surface and an outside-the-middle region where the distance from the middle surface is greater than the middle region. A line width of coil lines in the middle region is narrower than a line width of coil lines in the outside-the-middle region.

Abstract: There is provided a gradient coil device which can suppress any generation of an error magnetic field and thus an eddy current, and which can improve the image quality of a cross-sectional image. An MRI device includes a first coil generating a linear magnetic field distribution at an imaging region of the MRI device, and a second coil which suppresses any leakage of a magnetic field from the first coil to a static-magnetic-field coil device that generates a uniform magnetic field distribution at the imaging region.

Abstract: A gradient coil device includes a major axis gradient coil, having an ellipse in a cross section generating a gradient magnetic field inclined in a major axis direction of the ellipse at a magnetic field space; and a minor axis gradient coil, having an ellipse in a cross section generating a gradient magnetic field inclined in a minor axis direction of the ellipse at the magnetic field space. A length of the minor axis field coil in the center axis direction is shorter than a length of the major axis gradient coil in the center axis direction. A maximum value of a residual magnetic field generated by the minor axis gradient coil at a space outside the magnetic field space is equal to or smaller than a maximum value of a residual magnetic field generated by the major axis gradient coil at a space outside the magnetic field space.

Abstract: When the gradient magnetic field 9 is generated, a low magnetic field region 22 and a high magnetic field region 21 are generated where a magnetic field crossing at least one of the first forward coil 11a, a second forward coil 11b, first revere coil 11e, and a second reverse coil 11d has different intensities between the low and high magnetic field regions and the intensity in the high magnetic region is higher than the intensity in the low magnetic field region. A line width Dlh of the coil line in the high magnetic field region 21 is narrower than the line width Dll of the coil line 24 in the low magnetic field region 22. There is provided a gradient magnetic field coil can suppress in a usable range heat generations due to eddy current and due to a pulse large current which steeply varies.

Abstract: In the magnetic resonance imaging device, the distance between the first and second coils is different in the circumferential direction and has a first region (A1) (?=0, ?) and a second region (A2) (?=?/2) narrower than the first region (A1). In the first coil, wiring patterns (17a, 17b) on the side of a zero-plane (F0) passing through the center of the first coil and perpendicular to the axis direction (z-axis direction) meander in the circumferential direction such that the wiring patterns (17a, 17b) depart from the zero-plane (F0) in the first region (A1) and approach the zero-plane (F0) in the second region (A2). This provides a gradient magnetic field coil capable of configuring wiring patterns without using a loop coil that does not pass through the z-axis.

Abstract: When the gradient magnetic field 9 is generated, a low magnetic field region 22 and a high magnetic field region 21 are generated where a magnetic field crossing at least one of the first forward coil 11a, a second forward coil 11b, first revere coil 11e, and a second reverse coil 11d has different intensities between the low and high magnetic field regions and the intensity in the high magnetic region is higher than the intensity in the low magnetic field region. A line width Dlh of the coil line in the high magnetic field region 21 is narrower than the line width Dll of the coil line 24 in the low magnetic field region 22. There is provided a gradient magnetic field coil can suppress in a usable range heat generations due to eddy current and due to a pulse large current which steeply varies.

Abstract: An MRI apparatus excellent in magnetic field generation efficiency is provided. According to this invention, a main coil (52) of a gradient magnetic field coil (13) is partially recessed to reduce the total thickness of a radio-frequency coil (11) and a gradient magnetic field coil (13). That is, the main coil (52) is designed in a tubular shape, and the diameter r1 at the center portion of the imaging space is larger than the diameter r2 of the main coil end portion. Accordingly, the RF coil (11) can be disposed to be near to the gradient magnetic field coil (13) side without lowering the magnetic field generation efficiency.

Abstract: There is provided a gradient coil device which can suppress any generation of an error magnetic field and thus an eddy current, and which can improve the image quality of a cross-sectional image. An MRI device includes a first coil generating a linear magnetic field distribution at an imaging region of the MRI device, and a second coil which suppresses any leakage of a magnetic field from the first coil to a static-magnetic-field coil device that generates a uniform magnetic field distribution at the imaging region.

Abstract: A magnetic resonance imaging apparatus is provided in which vibration of a gradient magnetic field coil is reduced, the vibration is not transmitted to a static magnetic field correcting unit, and space can be saved.

Abstract: An MRI apparatus excellent in magnetic field generation efficiency is provided. According to this invention, a main coil (52) of a gradient magnetic field coil (13) is partially recessed to reduce the total thickness of a radio-frequency coil (11) and a gradient magnetic field coil (13). That is, the main coil (52) is designed in a tubular shape, and the diameter r1 at the center portion of the imaging space is larger than the diameter r2 of the main coil end portion. Accordingly, the RF coil (11) can be disposed to be near to the gradient magnetic field coil (13) side without lowering the magnetic field generation efficiency.

Abstract: [PROBLEMS] A magnetic resonance imaging apparatus in which vibration of a gradient magnetic field coil is reduced, the vibration is not transmitted to a static magnetic field correcting unit, and the space can be saved. [MEANS FOR SOLVING PROBLEMS] A tabular gradient magnetic field generating unit is placed over each opposing surface of support member therebetween. A static magnetic field correcting unit for correcting the uniformity of the static magnetic field is placed between the static magnetic field generating unit and the gradient magnetic field generating unit. The static magnetic field correcting unit is a tabular shim tray provided with magnetic body pieces for correcting the uniformity of the static magnetic field, and is placed over each of the pair of the opposing surfaces of static magnetic field generating units, with a second supporting member therebetween.