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公开(公告)号：US5289128A
公开(公告)日：1994-02-22
申请号：US859152
申请日：1992-03-27
IPC分类号： A61B5/055 , G01R33/20 , G01R33/38 , G01R33/385 , G01R33/421 , H01F6/00
CPC分类号： G01R33/3856 , G01R33/385 , G01R33/4215
摘要： An examination region (12) is defined within the bore of a superconducting magnet assembly (10). An RF coil (22) and gradient magnetic field coils (14) are disposed within the bore of the superconducting magnet assembly around the examination region. The superconducting magnet includes a hollow, cylindrical vacuum vessel (40). An annular, liquid helium holding low temperature reservoir (60) extends centrally through the vacuum vessel, but is sealed therefrom such that liquid helium is not drawn into the vacuum. A plurality of annular superconducting magnets (56) are received in the low temperature reservoir immersed in the liquid helium. A first cold shield (44) and a second cold shield (50) are mounted in the vacuum vessel surrounding the low temperature reservoir. A main magnetic field shield coil (66) is disposed in the low temperature reservoir outside of the annular superconducting magnets for canceling the magnetic field generated by the annular magnets surrounding the magnet. A gradient shield coil (70) is mounted in low temperature reservoir inside the annular superconducting magnets to cancel magnetic fields generated by the gradient magnetic field coils in the region beyond the gradient shield coil. The gradient shield coil is electromagnetically coupled to the gradient field coils to be driven by magnetic fields emanating therefrom. Optionally, the gradient shield coil can be constructed of a higher temperature superconducting material and disposed in association with one of the cold shields.
摘要翻译： 检查区域（12）被限定在超导磁体组件（10）的孔内。 RF线圈（22）和梯度磁场线圈（14）被布置在超导磁体组件的围绕检查区域的孔内。 超导磁体包括中空的圆柱形真空容器（40）。 一个环状的液氦保持低温储存器（60）在真空容器的中心延伸，但被密封，使得液氦不被吸入真空。 多个环形超导磁体（56）被容纳在浸入液氦的低温储存器中。 第一冷屏蔽（44）和第二冷屏蔽（50）安装在围绕低温储存器的真空容器中。 主磁场屏蔽线圈（66）设置在环形超导磁体外部的低温储存器中，用于抵消围绕磁体的环形磁体产生的磁场。 梯度屏蔽线圈（70）安装在环形超导磁体内部的低温储存器中，以消除梯度屏蔽线圈之外的区域中的梯度磁场线圈产生的磁场。 梯度屏蔽线圈与梯度场线圈电磁耦合，由其发出的磁场驱动。 可选地，梯度屏蔽线圈可以由更高温度的超导材料构成并且与其中一个冷屏蔽件相关联地设置。
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公开(公告)号：US5406204A
公开(公告)日：1995-04-11
申请号：US80413
申请日：1993-06-21
IPC分类号： G01R33/20 , A61B5/055 , G01R33/3815 , G01R33/385 , G01R33/421 , G01R33/422
CPC分类号： G01R33/3815 , G01R33/385 , G01R33/421 , G01R33/422 , G01R33/3856 , G01R33/4215
摘要： The magnetic field assembly of a magnetic resonance imaging device includes an annular superconducting magnet (10) which is mounted within a toroidal vacuum vessel (24). A cylindrical member (26) defines a central bore through which the superconducting magnets generate a temporally constant primary magnetic field. A cylindrical, dielectric former (46) is mounted in the bore displaced a small distance from the cylindrical member. A radio frequency coil (32) is mounted within the cylindrical member defining a patient receiving examination region. An RF shield (34) is mounted around the exterior peripheral surface of the former. Primary gradient coils (40) are mounted around and potted to the exterior of the dielectric former around the RF shield. Gradient shield or secondary coils (44) are potted around an exterior of the cylindrical member within the vacuum chamber. As illustrated in FIG. 3 , when unshielded gradient coils are used, the primary gradient coils and the RF shield are mounted around the outer diameter of the cylindrical member (26).
摘要翻译： 磁共振成像装置的磁场组件包括安装在环形真空容器（24）内的环形超导磁体（10）。 圆柱形构件（26）限定中心孔，超导磁体通过该中心孔产生时间上不变的初级磁场。 圆柱形电介质成形器（46）安装在距离圆柱形构件较小距离的孔中。 射频线圈（32）安装在限定患者接收检查区域的圆柱形构件内。 RF屏蔽件（34）围绕前者的外周表面安装。 初级梯度线圈（40）围绕RF屏蔽件安装在电介质成形器的外部并且封装在外部。 梯度屏蔽或次级线圈（44）围绕真空室内的圆柱形构件的外部进行灌封。 如图1所示。 如图3所示，当使用非屏蔽梯度线圈时，主梯度线圈和RF屏蔽围绕圆柱形部件（26）的外径安装。
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公开(公告)号：US5280247A
公开(公告)日：1994-01-18
申请号：US859154
申请日：1992-03-27
IPC分类号： A61B5/055 , G01R33/20 , G01R33/385 , G01R33/421
CPC分类号： G01R33/385
摘要： An examination region (12) is defined within the bore of a superconducting magnet assembly (10). An RF coil (22) and gradient magnetic field coils (14) are disposed within the bore of the superconducting magnetic assembly around the examination region. The superconducting magnet includes a hollow, tubular vacuum vessel (40) which contains a plurality of annular superconducting magnets (58). These superconducting magnets are held in a liquid helium holding reservoir (60) such that they are held below their superconducting temperature. A first cold shield (44) and a second cold shield (50 ) have tubular portions between the superconducting magnets and the examination region. These cylindrical portions each include a cylinder (70) of a electrically insulating material such as reinforced plastic. Thermally conductive layers (72) are defined on each surface and are divided by etched slots or resistance portions (74) into a multiplicity of elongated narrow segments (92). The narrow segments are constructed of a thermally conductive material, such as copper or aluminum, that also happens to be electrically conductive. The division of the foil layer into a multiplicity of segments divides the generated eddy currents into a like multiplicity of substantially canceling eddy currents (82) increasing the eddy current path length, increasing the total electrical resistance encountered, and reducing the amplitude and time constant of the resultant net eddy current and eddy magnetic field.
摘要翻译： 检查区域（12）被限定在超导磁体组件（10）的孔内。 RF线圈（22）和梯度磁场线圈（14）被布置在围绕检查区域的超导磁性组件的孔内。 超导磁体包括中空管状真空容器（40），其包含多个环形超导磁体（58）。 这些超导磁体被保持在液氦保持容器（60）中，使得它们保持在其超导温度以下。 第一冷屏蔽（44）和第二冷屏蔽（50）在超导磁体和检查区域之间具有管状部分。 这些圆柱形部分各自包括诸如增强塑料的电绝缘材料的圆筒（70）。 导热层（72）被限定在每个表面上，并被蚀刻的槽或电阻部分（74）分成多个细长窄段（92）。 窄段由也可能导电的导热材料（例如铜或铝）构成。 将箔层划分为多个段将生成的涡流分成相当大量的基本上消除的涡流（82），增加涡流路径长度，增加所遇到的总电阻，并减小振幅和时间常数 得到的净涡流和涡流磁场。
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公开(公告)号：US5424643A
公开(公告)日：1995-06-13
申请号：US80564
申请日：1993-06-21
IPC分类号： G01R33/20 , A61B5/055 , G01R33/34 , G01R33/385 , G01R33/421 , G01R33/422
CPC分类号： G01R33/34 , G01R33/385 , G01R33/422 , G01R33/3856 , G01R33/4215
摘要： A magnetic resonance imaging machine includes a toroidal vacuum dewer (24) which contains a superconducting magnet (10). A radio frequency coil (32) is mounted within a cylindrical bore (26) of the vacuum dewer. A cylindrical, dielectric former (46) supports an RF shield (34), a z-gradient coil (50), an x-gradient coil (52), and a y-gradient coil (54). The x and y-gradient coils are each composed of four like spiral coil constructions. A metallic layer is cut with cut lines (64) to define a generally spiral coil winding pattern. In a high current density region (68) in which the coil windings are narrower than a preselected width, the cut lines (76) are thinner. In lower current density regions (70), the cut lines (78) are thicker. In lower current density regions, two cut lines are defined between adjacent coil windings such that the coil windings are limited to a maximum width. Conductive islands (80) defined in the lower current density areas which are large enough to support detrimental eddy currents are preferably removed or at least modified such that their ability to support detrimental eddy currents is curtailed.
摘要翻译： 磁共振成像机包括含有超导磁体（10）的环形真空脱水器（24）。 射频线圈（32）安装在真空脱水器的圆柱形孔（26）内。 圆柱形电介质成形器（46）支撑RF屏蔽（34），z-梯度线圈（50），x-梯度线圈（52）和y-梯度线圈（54）。 x和y梯度线圈由四个类似的螺旋线圈结构组成。 用切割线（64）切割金属层以限定大致螺旋线圈绕组图案。 在其中线圈绕组比预选宽度窄的高电流密度区域（68）中，切割线（76）更薄。 在较低电流密度区域（70）中，切割线（78）较厚。 在较低的电流密度区域中，在相邻的线圈绕组之间限定两个切割线，使得线圈绕组被限制到最大宽度。 限定在足够大以支持有害涡流的较低电流密度区域中的导电岛（80）优选地被去除或至少被修改，使得它们支持有害涡流的能力受到限制。
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公开(公告)号：US20110241684A1
公开(公告)日：2011-10-06
申请号：US13034377
申请日：2011-02-24
IPC分类号： G01R33/44
CPC分类号： G01R33/3806 , A61B5/055 , A61N2005/1055 , G01R33/3802 , G01R33/3856 , G01R33/4808
摘要： A magnetic resonance imaging (MRI) system includes a split magnet system having a pair of MRI magnet housings separated by gap. A pair of main MRI magnets are disposed within respective MRI magnet housings. A plurality of buttress assemblies are attached to the MRI magnet housings. Some or all of the buttress assemblies are provided with removable connections to the MRI magnet housings. This allows for partial disassembly of the MRI system for improved transport and maneuverability for relocating the MRI system. The MRI system can include a gantry in the gap for supporting a radiation therapy system. Also, the removably buttress assemblies can be used for housing conduits, such as electrical and fluid conduits, between the pair of MRI magnet housings.
摘要翻译： 磁共振成像（MRI）系统包括具有由间隙隔开的一对MRI磁体壳体的分裂磁体系统。 一对主磁共振磁铁磁铁设置在相应的磁共振磁体外壳内。 多个支撑组件附接到MRI磁体壳体。 部分或全部支撑组件设置有与磁共振磁体外壳的可拆卸连接。 这允许MRI系统的部分拆卸以改善用于重新定位MRI系统的运输和机动性。 MRI系统可以包括用于支撑放射治疗系统的间隙中的台架。 此外，可移除的支撑组件可以用于在一对MRI磁体壳体之间的壳体导管，例如电气和流体导管。
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公开(公告)号：US20110121832A1
公开(公告)日：2011-05-26
申请号：US12951976
申请日：2010-11-22
IPC分类号： G01R33/44
CPC分类号： G01R33/3806 , A61N2005/1055 , G01R33/385 , G01R33/3856 , G01R33/3858 , G01R33/4215 , G01R33/4808
摘要： Gradient coil assemblies for horizontal magnetic resonance imaging systems (MRIs) and methods of their manufacture. Some embodiments may be used with open MRIs and can be used with an instrument placed in the gap of the MRI. In general, concentrations of conductors or radially oriented conductors may be moved away from the gap of the MRI so as to reduce eddy currents that may be induced in any instrument placed within the gap. Systems for directly cooling primary gradient and shield coils may be utilized and various coil supporting structures may be used to assist in coil alignment or to facilitate use of an instrument in the MRI gap.
摘要翻译： 用于水平磁共振成像系统（MRI）的梯度线圈组件及其制造方法。 一些实施例可以与开放MRI一起使用，并且可以与置于MRI间隙中的器械一起使用。 通常，导体或径向取向的导体的浓度可以远离MRI的间隙移动，以便减少可能在放置在间隙内的任何仪器中引起的涡流。 可以使用用于直接冷却主梯度和屏蔽线圈的系统，并且可以使用各种线圈支撑结构来辅助线圈对准或便于在MRI间隙中使用仪器。
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公开(公告)号：US4780675A
公开(公告)日：1988-10-25
申请号：US85956
申请日：1987-08-14
CPC分类号： G01R33/561
摘要： An incomplete set of magnetic resonance image data is collected and stored in a view memory (40). The incomplete set of image data includes a central or first set of data values (42, 42') and a side or second set of data values (44, 44'). The central data set is operated on by a roll-off filter (64) and a Fourier transform (66) to create a normalized phase map (72). The first and second data sets are Fourier transformed (82) and phase corrected (86) by being multiplied with a complex conjugate (88) of the corresponding phase map data value. A third data set (46, 46') is generated (90) by determining the complex conjugate of the second or side data set. The third data set is Fourier transformed (94) and multiplied (98) by a corresponding value from the phase map to produce a second phase corrected image representation. The first and second phase corrected image representations are summed (100) and stored in a resultant image memory (102).
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公开(公告)号：US08803524B2
公开(公告)日：2014-08-12
申请号：US13034377
申请日：2011-02-24
CPC分类号： G01R33/3806 , A61B5/055 , A61N2005/1055 , G01R33/3802 , G01R33/3856 , G01R33/4808
摘要： A magnetic resonance imaging (MRI) system includes a split magnet system having a pair of MRI magnet housings separated by gap. A pair of main MRI magnets are disposed within respective MRI magnet housings. A plurality of buttress assemblies are attached to the MRI magnet housings. Some or all of the buttress assemblies are provided with removable connections to the MRI magnet housings. This allows for partial disassembly of the MRI system for improved transport and maneuverability for relocating the MRI system. The MRI system can include a gantry in the gap for supporting a radiation therapy system. Also, the removably buttress assemblies can be used for housing conduits, such as electrical and fluid conduits, between the pair of MRI magnet housings.
摘要翻译： 磁共振成像（MRI）系统包括具有由间隙隔开的一对MRI磁体壳体的分裂磁体系统。 一对主磁共振磁铁磁铁设置在相应的磁共振磁体外壳内。 多个支撑组件附接到MRI磁体壳体。 部分或全部支撑组件设置有与磁共振磁体外壳的可拆卸连接。 这允许MRI系统的部分拆卸以改善用于重新定位MRI系统的运输和机动性。 MRI系统可以包括用于支撑放射治疗系统的间隙中的台架。 此外，可移除的支撑组件可以用于在一对MRI磁体壳体之间的壳体导管，例如电气和流体导管。
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公开(公告)号：US08896308B2
公开(公告)日：2014-11-25
申请号：US12951976
申请日：2010-11-22
IPC分类号： G01V3/00 , G01R33/421 , G01R33/38 , G01R33/48 , G01R33/385
CPC分类号： G01R33/3806 , A61N2005/1055 , G01R33/385 , G01R33/3856 , G01R33/3858 , G01R33/4215 , G01R33/4808
摘要： Gradient coil assemblies for horizontal magnetic resonance imaging systems (MRIs) and methods of their manufacture. Some embodiments may be used with open MRIs and can be used with an instrument placed in the gap of the MRI. In general, concentrations of conductors or radially oriented conductors may be moved away from the gap of the MRI so as to reduce eddy currents that may be induced in any instrument placed within the gap. Systems for directly cooling primary gradient and shield coils may be utilized and various coil supporting structures may be used to assist in coil alignment or to facilitate use of an instrument in the MRI gap.
摘要翻译： 用于水平磁共振成像系统（MRI）的梯度线圈组件及其制造方法。 一些实施例可以与开放MRI一起使用，并且可以与置于MRI间隙中的器械一起使用。 通常，导体或径向取向的导体的浓度可以远离MRI的间隙移动，以便减少可能在放置在间隙内的任何仪器中引起的涡流。 可以使用用于直接冷却主梯度和屏蔽线圈的系统，并且可以使用各种线圈支撑结构来辅助线圈对准或便于在MRI间隙中使用仪器。
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公开(公告)号：US4912413A
公开(公告)日：1990-03-27
申请号：US260402
申请日：1988-10-20
IPC分类号： G01R33/54 , G01R33/561 , G01R33/565
CPC分类号： G01R33/54 , G01R33/561 , G01R33/565
摘要： An incomplete set of magnetic resonance image data is collected and stored in a view memory (40). The incomplete set of image data includes a central or first set of data values (42, 42') and half of the remaining data values (44, 44'). A symmetric data set which fills the other remaining half (46, 46') of the data values is generated (90) by determining the complex conjugate of each value of the incomplete data set. The incomplete and symmetric data sets are Fourier transformed (64, 94) to create first and second images f.sub.1 (x,y) and f.sub.2 (x,y). The first and second images are multiplied (100, 104) by conjugately symmetric phase correction values e.sup.i.phi.(x,y) and e.sup.-i.phi.(x,y) from a phase correction memory (70) to produce phase corrected images. The first and second phase corrected image representations are summed (110) and displayed (114). The phase correction values .phi.(x,y) may be derived (68) from the first image or from a phase image (86) derived (80, 82, 84) from a central or other portion of the acquired incomplete image data set.
摘要翻译： 一组不完整的磁共振图像数据被收集并存储在视图存储器（40）中。 不完整的图像数据集合包括中央或第一组数据值（42,42'）和剩余数据值（44,44'）的一半。 通过确定不完整数据集的每个值的复共轭来生成（90）填充数据值的另一半（46,46'）的对称数据集。 不完全和对称的数据集被傅里叶变换（64,94）以产生第一和第二图像f1（x，y）和f2（x，y）。 第一和第二图像通过来自相位校正存储器（70）的共对称相位校正值ei phi（x，y）和e-i phi（x，y）相乘（100,104）以产生相位校正图像。 将第一和第二相位校正图像表示相加（110）并显示（114）。 相位校正值phi（x，y）可以从第一图像或从所获取的不完整图像数据集合的中心部分或其他部分导出（80,82,84）的相位图像（86）导出（68）。
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