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1.发明公开Quadrature RF surface coil for magnetic resonance imaging 审中-公开Quadratur-RF-Oberflächenspulefürdie Magnetresonanzbildgebung
公开(公告)号：EP1004885A3
公开(公告)日：2002-05-02
申请号：EP99308922.6
申请日：1999-11-09
IPC分类号： G01R33/341
CPC分类号： G01R33/3678
摘要： A magnetic imaging apparatus generates a main magnetic field longitudinally through an image region and excites magnetic resonance in selected nuclei in a patient or subject disposed in the image area. The resonating nuclei generate radio frequency magnetic resonance signals which are received by a quadrature highpass ladder surface coil (D). The highpass ladder coil includes a central leg (34) having a capacitive element (C V ) disposed symmetrically about a midpoint (44). A like number of additional legs (30, 32, 36, 38) are disposed parallel to and symmetrically on opposite side of the central leg. Side elements (40, 42) include capacitive elements (C A ) which interconnect adjacent ends of each of the legs. The capacitive elements are disposed symmetrically about the midpoint (44) and are selected such that the coil supports at least two intrinsic resonant modes including an odd mode (50) and an even mode (52). The even mode is sensitive to fields in the plane of the coil and the odd mode is sensitive to fields in a plane orthogonal to the coil.
摘要翻译： 磁成像装置通过图像区域纵向地产生主磁场，并且在设置在图像区域中的患者或被摄体中的选定细胞核中激发磁共振。 谐振核产生由正交高通梯形线圈（D）接收的射频磁共振信号。 高速梯形线圈包括具有围绕中点（44）对称设置的电容元件（CV）的中心支脚（34）。 相似数量的附加腿（30,32,36,38）平行于对称地设置在中心腿的相对侧上。 侧元件（40,42）包括互连每个支腿的相邻端部的电容元件（CA）。 电容元件围绕中点（44）对称设置，并且被选择为使得线圈支持包括奇数模式（50）和偶模式（52）的至少两个固有谐振模式。 偶数模式对线圈平面中的场敏感，奇数模式对垂直于线圈的平面中的场敏感。
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公开(公告)号：EP1128188A2
公开(公告)日：2001-08-29
申请号：EP01301564.9
申请日：2001-02-21
IPC分类号： G01R33/34
CPC分类号： G01R33/34046
摘要： A tunable radio frequency birdcage coil (30) is oriented vertically in a bore-type magnetic resonance apparatus. The birdcage coil (30) includes a pair of end rings (60, 62) disposed in parallel planes along a coil axis which is orthogonal to the main magnetic field. A plurality of rungs (64) electrically interconnect the end rings (60, 62) to form a generally cylindrical volume. The end rings (60, 62) and rungs (64) are mounted on a hinged (68) dielectric former (66). Conductive connectors (70) releasably fasten the end rings (60, 62) so that the coil (30) may be opened and closed to receive a portion of a subject to be examined. A conductive loop (80) is inductively coupled and positioned parallel to the end rings (60, 62). The conductive loop (80) is slidably adjustable along the coil axis for matching and tuning end-ring modes of the coil. The coil is oriented to provide a subject disposed therein with an open view for fMRI applications. Means for stimulating the visual senses (100) is mounted adjacent the examination region (14) to facilitate fMRI applications.
摘要翻译： 可调谐射频鸟笼线圈（30）在孔型磁共振装置中垂直取向。 鸟笼线圈（30）包括沿着与主磁场正交的线圈轴设置在平行平面中的一对端环（60,62）。 多个梯级（64）电连接端环（60,62）以形成大致圆柱形的体积。 端环（60,62）和梯级（64）安装在铰接（68）电介质成形器（66）上。 导电连接器（70）可释放地紧固端环（60,62），使得线圈（30）可以被打开和关闭以接收待检查对象的一部分。 导电回路（80）感应耦合并平行于端环（60,62）定位。 导电回路（80）可沿着线圈轴线可滑动地调节，用于匹配和调谐线圈的端环模式。 线圈被定向成提供设置在其中的用于fMRI应用的开放视野的对象。 用于刺激视觉感测的装置（100）安装在检查区域（14）附近，以便于fMRI应用。
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公开(公告)号：EP1113286A2
公开(公告)日：2001-07-04
申请号：EP00311406.3
申请日：2000-12-19
IPC分类号： G01R33/34 , G01R33/341
CPC分类号： G01R33/3678 , G01R33/34046
摘要： A quadrature RF coil assembly (50) is employed for quadrature excitation and/or reception in an open or vertical field magnetic resonance apparatus. The quadrature RF coil (50) includes a plurality of parallel rung elements (70, 72, 74, 76, 78) . A pair of electrical conductive end segments (80, 82) connect the plurality of rung elements. Capacitive elements (C V , C A ) interrupt a central rung element and the end segments. Preferably, the capacitive elements (C V , C A ) are arranged in a high-pass configuration such that the two highest resonant modes, an odd mode (90) and an even mode (92) , are tuned to have peak responsivity to a common imaging frequency. The odd mode (90) is responsive to magnetic fields which are normal to the coil (50) , while the even mode is responsive to magnetic fields which are parallel to the coil (50) and perpendicular to the main magnetic field. In one embodiment, the quadrature coil (50) is curved such that it is partially wrapped around a portion of a subject (100) with the rung elements (70, 72, 74, 76, 78) of the coil (50) parallel to the main magnetic field B 0 . The quadrature coil (50) provides improved B 1 field uniformity and greater tuning stability due to reduced localized electric field effects. The coil (50) provides greater accessibility for interventional procedures conducted in a vertical field or open magnetic resonance imaging system.
摘要翻译： 正交RF线圈组件（50）用于开放或垂直场磁共振设备中的正交激励和/或接收。 正交RF线圈（50）包括多个平行梯级元件（70,72,74,76,78）。 一对导电端部段（80,82）连接多个梯级元件。 电容元件（CV，CA）中断中央梯级元件和端段。 优选地，电容元件（CV，CA）被布置成高通配置，使得将两个最高谐振模式（奇模式（90）和偶模式（92））调谐为对共同成像具有峰值响应性 频率。 奇数模式（90）响应于垂直于线圈（50）的磁场，而偶模式响应于平行于线圈（50）并垂直于主磁场的磁场。 在一个实施例中，正交线圈（50）是弯曲的，使得它被部分缠绕在被检体（100）的一部分上，线圈（50）的梯级元件（70,72,74,76,78）平行于 主磁场B0。 正交线圈（50）由于减小的局部电场效应而提供改进的B1场均匀性和更大的调谐稳定性。 线圈（50）为在垂直场或开放磁共振成像系统中进行的介入程序提供更大的可接近性。
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公开(公告)号：EP0992812A3
公开(公告)日：2003-01-15
申请号：EP99307585.2
申请日：1999-09-27
发明人： Shvartsman, Shmaryu M. , Brown, Robert , Fujita, Hiroyuki , Morich, Michael A. , Petropoulos, Labros S.
IPC分类号： G01R33/42
CPC分类号： G01R33/4215
摘要： A method of designing an active shield for substantially zeroing an electro-magnetic field on one side of a predetermined boundary is provided. It includes defining a geometry for a primary structure which, in the case of zeroing a magnetic field, carries a first current distribution on its surface. A geometry is also defined for a secondary structure which, again in the case of zeroing a magnetic field, carries a second current distribution on its surface. In the case of zeroing an electric field, the current distributions are replaced with charge distributions. A total magnetic or electric field resulting from a combination of the first and second current or charge distributions respectively is constrained such that normal components (in the magnetic field case) or tangential components (in the electric field case) thereof vanish at the surface of one of the primary and secondary structures. The first current or charge distribution is constrained to the surface of the primary structure, and the second current or charge distribution is constrained to the surface of the secondary structure. The first and second current or charge distributions are then calculated concurrently while observing the constraints such that a predetermined magnetic or electric field is achieved in a first region and a magnetic or electric field on one side of a predetermined boundary is substantially zeroed.
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公开(公告)号：EP1113285A2
公开(公告)日：2001-07-04
申请号：EP00311402.2
申请日：2000-12-19
IPC分类号： G01R33/34
CPC分类号： G01R33/3415 , G01R33/34 , G01R33/34061
摘要： A crossed-ladder RF coil assembly ( 48 ) is employed for quadrature excitation and/or reception in an open or vertical field magnetic resonance apparatus. The RF coil assembly ( 48, 70, 90 ) includes a pair of coil assemblies ( 50, 52; 70, 72; 100, 102 ) which are disposed in a parallel relationship. Coil arrays ( 50, 52; 100, 102 ) include at least two ladder RF coils ( 50 1 , 50 2 , 50 3 ; 52 1 , 52 2 , 52 3 ; 100 1 ..., 100 8 ; 102 1 ,..., 102 8 ) which are disposed in an overlapping relationship and are rotated by 90° relative to one another. Each ladder RF coil of one coil array is rotated by 90° relative to adjoining ladder coils and each corresponding ladder RF coil of the other coil array. The crossed-ladder RF coil assembly ( 48 ) provides better B 1 field uniformity and elongated anatomical coverage for spine and neck imaging. In addition, the RF coil assembly reduces noise from the body at higher fields in vertical field magnetic resonance systems.
摘要翻译： 甲交叉梯子RF线圈组件（48）被用于正交激励和/或接收在开放或垂直场磁共振装置。 的RF线圈组件（48，70，90）包括一对线圈组件（50，52; 70，72; 100，102），它们是在一个平行关系地设置。 线圈阵列（50，52; 100，102）包括至少两个阶梯的RF线圈（501，502，503; 1021，...，1028; 521，522，523 1001 ...，1008），它们是在位于 以重叠关系，并通过90°相转动到彼此。 一个线圈阵列的每个梯RF线圈由相对90°到邻接的梯子线圈和另一线圈阵列的每个相应的梯RF线圈旋转。 叉的梯子RF线圈组件（48）提供了更好的B1场的均匀性和长形解剖覆盖脊柱和颈部成像。 此外，RF线圈组件在垂直场磁共振系统更高字段减少了从身体噪声。
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公开(公告)号：EP1085337A3
公开(公告)日：2003-05-28
申请号：EP00307564.5
申请日：2000-09-01
CPC分类号： G01R33/34046 , G01R33/3628
摘要： A magnetic resonance apparatus includes a main magnetic field source (12) for providing a magnetic field (B 0 ) along a main field axis. A transmitter (34) and transmit coils (30, 32) excite a nuclei of an object to resonate. The resonating nuclei generate magnetic resonance signals detected by a volume coil (50) including a pair of end rings (70, 72) separated along a coil axis (Y). The end rings (70, 72) are electrically interconnected by a plurality of rungs (74) disposed about the rings. A conductive loop (80) is concentrically disposed between and inductively coupled to the end rings. The loop includes an electrical conductor (82) preferably surrounding the rungs (74), and positioned parallel to the end rings (70, 72). A capacitive element (84), in electrical communication with the conductor (82), is selected or adjusted to tune the loop (80) to signals at a selected frequency. Moreover, the loop (80) is slidably positionable along the coil axis (Y) and has an adjustable capacitor (84) to match or tune the loop to signals at the selected frequency.
摘要翻译： 磁共振装置包括用于沿主场轴提供磁场（B0）的主磁场源（12）。 发射器（34）和发射线圈（30,32）激发物体的核以产生谐振。 谐振核产生由包括沿着线圈轴线（Y）分离的一对端环（70,72）的体积线圈（50）检测的磁共振信号。 端环（70,72）通过围绕环设置的多个梯级（74）电互连。 导电回路（80）同心地设置在端环之间并感应耦合到端环。 环路包括优选围绕梯级（74）并且平行于端环（70,72）定位的电导体（82）。 选择或调节与导体（82）电连通的电容元件（84），以将环路（80）调谐到选定频率的信号。 此外，环路（80）可沿着线圈轴线（Y）可滑动定位，并且具有可调电容器（84），以将环路与所选频率的信号相匹配或调谐。
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公开(公告)号：EP1113286A3
公开(公告)日：2002-05-02
申请号：EP00311406.3
申请日：2000-12-19
IPC分类号： G01R33/34 , G01R33/341
CPC分类号： G01R33/3678 , G01R33/34046
摘要： A quadrature RF coil assembly (50) is employed for quadrature excitation and/or reception in an open or vertical field magnetic resonance apparatus. The quadrature RF coil (50) includes a plurality of parallel rung elements (70, 72, 74, 76, 78) . A pair of electrical conductive end segments (80, 82) connect the plurality of rung elements. Capacitive elements (C V , C A ) interrupt a central rung element and the end segments. Preferably, the capacitive elements (C V , C A ) are arranged in a high-pass configuration such that the two highest resonant modes, an odd mode (90) and an even mode (92) , are tuned to have peak responsivity to a common imaging frequency. The odd mode (90) is responsive to magnetic fields which are normal to the coil (50) , while the even mode is responsive to magnetic fields which are parallel to the coil (50) and perpendicular to the main magnetic field. In one embodiment, the quadrature coil (50) is curved such that it is partially wrapped around a portion of a subject (100) with the rung elements (70, 72, 74, 76, 78) of the coil (50) parallel to the main magnetic field B 0 . The quadrature coil (50) provides improved B 1 field uniformity and greater tuning stability due to reduced localized electric field effects. The coil (50) provides greater accessibility for interventional procedures conducted in a vertical field or open magnetic resonance imaging system.
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公开(公告)号：EP1113285A3
公开(公告)日：2002-04-10
申请号：EP00311402.2
申请日：2000-12-19
IPC分类号： G01R33/34 , G01R33/341 , G01R33/3415
CPC分类号： G01R33/3415 , G01R33/34 , G01R33/34061
摘要： A crossed-ladder RF coil assembly ( 48 ) is employed for quadrature excitation and/or reception in an open or vertical field magnetic resonance apparatus. The RF coil assembly ( 48, 70, 90 ) includes a pair of coil assemblies ( 50, 52; 70, 72; 100, 102 ) which are disposed in a parallel relationship. Coil arrays ( 50, 52; 100, 102 ) include at least two ladder RF coils ( 50 1 , 50 2 , 50 3 ; 52 1 , 52 2 , 52 3 ; 100 1 ..., 100 8 ; 102 1 ,..., 102 8 ) which are disposed in an overlapping relationship and are rotated by 90° relative to one another. Each ladder RF coil of one coil array is rotated by 90° relative to adjoining ladder coils and each corresponding ladder RF coil of the other coil array. The crossed-ladder RF coil assembly ( 48 ) provides better B 1 field uniformity and elongated anatomical coverage for spine and neck imaging. In addition, the RF coil assembly reduces noise from the body at higher fields in vertical field magnetic resonance systems.
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公开(公告)号：EP1085337A2
公开(公告)日：2001-03-21
申请号：EP00307564.5
申请日：2000-09-01
CPC分类号： G01R33/34046 , G01R33/3628
摘要： A magnetic resonance apparatus includes a main magnetic field source (12) for providing a magnetic field (B 0 ) along a main field axis. A transmitter (34) and transmit coils (30, 32) excite a nuclei of an object to resonate. The resonating nuclei generate magnetic resonance signals detected by a volume coil (50) including a pair of end rings (70, 72) separated along a coil axis (Y). The end rings (70, 72) are electrically interconnected by a plurality of rungs (74) disposed about the rings. A conductive loop (80) is concentrically disposed between and inductively coupled to the end rings. The loop includes an electrical conductor (82) preferably surrounding the rungs (74), and positioned parallel to the end rings (70, 72). A capacitive element (84), in electrical communication with the conductor (82), is selected or adjusted to tune the loop (80) to signals at a selected frequency. Moreover, the loop (80) is slidably positionable along the coil axis (Y) and has an adjustable capacitor (84) to match or tune the loop to signals at the selected frequency.
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公开(公告)号：EP1128188A3
公开(公告)日：2003-05-21
申请号：EP01301564.9
申请日：2001-02-21
IPC分类号： G01R33/34
CPC分类号： G01R33/34046
摘要： A tunable radio frequency birdcage coil (30) is oriented vertically in a bore-type magnetic resonance apparatus. The birdcage coil (30) includes a pair of end rings (60, 62) disposed in parallel planes along a coil axis which is orthogonal to the main magnetic field. A plurality of rungs (64) electrically interconnect the end rings (60, 62) to form a generally cylindrical volume. The end rings (60, 62) and rungs (64) are mounted on a hinged (68) dielectric former (66). Conductive connectors (70) releasably fasten the end rings (60, 62) so that the coil (30) may be opened and closed to receive a portion of a subject to be examined. A conductive loop (80) is inductively coupled and positioned parallel to the end rings (60, 62). The conductive loop (80) is slidably adjustable along the coil axis for matching and tuning end-ring modes of the coil. The coil is oriented to provide a subject disposed therein with an open view for fMRI applications. Means for stimulating the visual senses (100) is mounted adjacent the examination region (14) to facilitate fMRI applications.
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