公开(公告)号：US5585724A

公开(公告)日：1996-12-17

申请号：US488166

申请日：1995-06-12

申请人： Michael A. Morich ,  Labros S. Petropoulos

发明人： Michael A. Morich ,  Labros S. Petropoulos

IPC分类号： A61B17/34 ,  A61B19/00 ,  G01R33/28 ,  G01R33/34 ,  G01R33/385 ,  G01V3/00

CPC分类号： G01R33/385 ,  A61B90/17 ,  A61B90/37 ,  A61B17/3403 ,  A61B2034/107 ,  A61B2090/374 ,  A61B34/20 ,  G01R33/285

摘要： A patient support (40) has lower sections (50a, 50b) of first and second gradient coil assembly portions (42a, 42b) affixed thereto. Upper sections (52a, 52b) of the gradient coil assembly portions are selectively removable from the lower gradient coil assembly sections. The gradient coil assembly sections are mounted such that an interstitial gap is defined therebetween. The gradient coil assembly portions are configured to fit snugly around the patient's torso below the shoulders and around the patient's head, but are too small in diameter to pass around the patient's shoulders. The radio frequency coil (44) has a lower portion (60) disposed below the patient's shoulders and an upper portion (62) removably positionable above the patient's shoulders. The gap between the two gradient coil assembly portions is preferably between 1/2 and 3/4 of a diameter of the gradient coil portions. An invasive medical instrument, such as a biopsy gun (100), is mounted to the patient support adjacent the gap between the gradient coil portions for performing invasive medical procedures on a portion of the patient through the gap between the gradient coil portions.

摘要翻译： 患者支撑件（40）具有固定到其上的第一和第二梯形线圈组件部分（42a，42b）的下部（50a，50b）。 梯度线圈组件部分的上部分（52a，52b）可选择性地从下部梯度线圈组件部分移除。 倾斜线圈组件段被安装成使得间隙间隙被限定在其间。 梯度线圈组件部分被配置成紧贴在患者的躯干周围的肩部周围并且围绕患者的头部，但是直径太小以便绕过患者的肩部。 射频线圈（44）具有设置在患者肩部下方的下部（60）和可拆卸地定位在患者肩部上方的上部（62）。 两个梯度线圈组件部分之间的间隙优选为梯度线圈部分直径的+ E，fra 1/2 + EE和+ E，fra 3/4 + EE之间。 诸如活检枪（100）的入侵医疗器械安装到邻近梯度线圈部分之间的间隙处的患者支架，用于通过梯度线圈部分之间的间隙在患者的一部分上执行侵入性医疗过程。

公开(公告)号：US5550472A

公开(公告)日：1996-08-27

申请号：US421837

申请日：1995-04-13

申请人： Mark A. Richard ,  Michael A. Morich ,  Labros S. Petropoulos

发明人： Mark A. Richard ,  Michael A. Morich ,  Labros S. Petropoulos

IPC分类号： G01R33/3873 ,  G01R33/421 ,  G01R33/422 ,  G01V3/00

CPC分类号： G01R33/3873 ,  G01R33/4215 ,  G01R33/422

摘要： A toroidal housing (18), such as a vacuum dewar, contains magnets (10, 12) for generating a temporally constant magnetic field through a central bore (14). Gradient coils (32, 42) are mounted around the bore defining a space therebetween. A radio frequency shield (78) is disposed radially inward from the gradient coils. Inside the radio frequency shield, an inner shimming assembly (60) includes a dielectric cylinder (62) having annular grooves around its periphery. Segmented ferrous material (66) is arranged in annular rings in the grooves. The ferrous material is segmented into small pieces electrically insulated from each other to limit radio frequency and gradient frequency eddy currents. A radio frequency coil (70) is mounted inside of the annular ferrous shims (66). Preferably, additional shim trays (50) which carry shims (54) are mounted in the space between the primary and secondary gradient coils.

摘要翻译： 诸如真空杜瓦瓶的环形壳体（18）包含用于通过中心孔（14）产生时间上恒定的磁场的磁体（10,12）。 梯形线圈（32,42）安装在孔周围，限定了它们之间的空间。 射频屏蔽（78）从梯度线圈径向向内设置。 在射频屏蔽内部，内部匀场组件（60）包括具有围绕其周边的环形槽的介质筒（62）。 分段铁质材料（66）以凹槽中的环形环布置。 铁质材料被分割成彼此电绝缘的小块，以限制射频和梯度频率涡流。 射频线圈（70）安装在环形铁片（66）的内部。 优选地，带有垫片（54）的附加垫片（50）安装在初级和次级梯度线圈之间的空间中。

公开(公告)号：US6011394A

公开(公告)日：2000-01-04

申请号：US908359

申请日：1997-08-07

申请人： Labros S. Petropoulos ,  Clarence E. Payton ,  Michael A. Morich ,  Gordon D. DeMeester

发明人： Labros S. Petropoulos ,  Clarence E. Payton ,  Michael A. Morich ,  Gordon D. DeMeester

IPC分类号： G01R33/385 ,  A61B5/055 ,  G01R33/421 ,  H01F7/20 ,  G01V3/00

CPC分类号： G01R33/4215 ,  G01R33/3856

摘要： A superconducting magnetic imaging apparatus includes a vacuum vessel (16) having a central helium reservoir (20) in which superconducting magnetic coil windings (12) are maintained at a superconducting temperature. The vacuum vessel defines an internal bore (22) within which a self-shielded gradient coil assembly (26) and an RF coil (30) are received. The self-shielded coil assembly includes a single former (50) which defines an imaging region (14) within which an imaged portion of a subject is received. Primary x, y, and z-gradient coils (72-76) are positioned over an RF ground screen (70) that is bonded to the former (50). A number of comb-like spacers (84) extend from the former to supporting shield x, y, and z-gradient coils (110-114). The comb-like spacers define passages between the primary and secondary gradient coils which receive inner and outer cooling tubes (90, 92) and shim tray molds (108). The fully assembled gradient coil assembly is potted to form a unitary structure in a single potting step. The shim tray molds are subsequently removed to define channels or pockets suitable for receiving shim trays (118).

摘要翻译： 超导磁性成像装置包括具有中心氦储存器（20）的真空容器（16），超导磁性线圈绕组（12）保持在超导温度下。 真空容器限定内部孔（22），在其内接收自屏蔽梯度线圈组件（26）和RF线圈（30）。 自屏蔽线圈组件包括限定成像区域（14）的单个成形器（50），在该成像区域内接收被摄体的成像部分。 主x，y和z梯度线圈（72-76）位于结合到前者（50）的RF接地屏（70）上。 多个梳状间隔物（84）从前者延伸到支撑屏蔽x，y和z-梯度线圈（110-114）。 梳状间隔件限定了接收内部和外部冷却管（90,92）和垫片托盘模具（108）的主梯度线圈和次级梯度线圈之间的通道。 完全组装的梯度线圈组件被封装以在单个灌封步骤中形成单一结构。 随后卸下垫片托盘模具以限定适于接收垫片托盘（118）的通道或袋子。

公开(公告)号：US5942898A

公开(公告)日：1999-08-24

申请号：US988045

申请日：1997-12-10

申请人： Labros S. Petropoulos ,  Michael A. Morich

发明人： Labros S. Petropoulos ,  Michael A. Morich

IPC分类号： G01R33/38 ,  G01R33/381 ,  G01R33/385 ,  G01V3/00

CPC分类号： G01R33/385 ,  G01R33/3806 ,  G01R33/381

摘要： A magnetic resonance imaging apparatus has a main magnet (20) having opposite first and second poles (22, 24) arranged facing one another to define a subject receiving region (14) therebetween. The main magnet (20) generates a main magnetic field (12) within the subject receiving region (14). The main magnetic field (12) has non-uniformities and radial components at the periphery of the subject receiving region (14). A radio frequency coil (74) is disposed about the subject receiving region (14) to transmit radio frequency signals into the subject receiving region (14) and a receiver receives radio frequency signals therefrom. A shielded thrust balanced bi-planar gradient coil assembly (50) is included. The shielded thrust balanced bi-planar gradient coil assembly (50) has at least one pair of windings for generating substantially linear magnetic gradients across the subject receiving region (14). Each pair of windings includes a first set of windings (52) and a second set of windings (54), and each set of windings includes at least a primary winding (56) and a secondary winding (58). The first and second set of windings (52, 54) are positioned on opposite sides of the subject receiving region (14) near the first and second pole pieces (22, 24). The secondary windings (58) are positioned between their respective primary windings (56) and their associated pole pieces (22, 24). The first and second set of windings (52, 54) are arranged such that the net thrust forces acting thereon generated by interaction between the main magnetic field (12) and electrical current pulses through the windings are substantially zero.

摘要翻译： 磁共振成像装置具有主磁体（20），该主磁体具有相对的彼此面对的第一和第二极（22,24），以在它们之间限定对象接收区域（14）。 主磁体（20）在对象接收区域（14）内产生主磁场（12）。 主磁场（12）在对象接收区域（14）的周围具有不均匀性和径向分量。 射频线圈（74）围绕被摄体接收区域（14）设置，以将射频信号传输到被摄体接收区域（14），并且接收器从其接收射频信号。 包括屏蔽推力平衡双平面梯度线圈组件（50）。 屏蔽推力平衡双平面梯度线圈组件（50）具有至少一对绕组，用于在对象接收区域（14）上产生基本线性的磁梯度。 每对绕组包括第一组绕组（52）和第二组绕组（54），并且每组绕组至少包括初级绕组（56）和次级绕组（58）。 第一和第二组绕组（52,54）位于第一和第二极片（22,24）附近的对象接收区域（14）的相对侧上。 次级绕组（58）位于它们各自的初级绕组（56）及其相关联的极片（22,24）之间。 第一和第二组绕组（52,54）被布置成使得通过主磁场（12）和通过绕组的电流脉冲之间的相互作用产生的净推力大致为零。

公开(公告)号：US06236203B1

公开(公告)日：2001-05-22

申请号：US09162005

申请日：1998-09-28

申请人： Shmaryu M. Shvartsman ,  Robert W. Brown ,  Hiroyuki Fujita ,  Michael A. Morich ,  Labros S. Petropoulos

发明人： Shmaryu M. Shvartsman ,  Robert W. Brown ,  Hiroyuki Fujita ,  Michael A. Morich ,  Labros S. Petropoulos

IPC分类号： G01R3320

CPC分类号： G01R33/4215

摘要： Methods of designing an active shield for substantially zeroing an electro-magnetic field on one side of a predetermined boundary in open magnetic resonance imaging systems and in open electric systems are provided. The methods include defining a finite length geometry for a primary structure which, in the case of zeroing a magnetic field, carries a first current distribution on its surface. A finite length geometry is also defined for a secondary structure which, 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 substantially 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 allowing both the first and second current or charge distributions to vary 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.

摘要翻译： 提供了在开放式磁共振成像系统和开放式电气系统中设计用于使预定边界的一侧上的电磁场基本归零的有源屏蔽的方法。 这些方法包括为初级结构定义有限长几何形状，在使磁场归零的情况下，其在其表面上承载第一电流分布。 还对二次结构定义了有限长几何形状，在二次结构的归零的情况下，在其表面上承载第二电流分布。 在电场归零的情况下，电流分布被电荷分布替代。 分别由第一和第二电流或电荷分布的组合产生的总磁场或电场被约束，使得正常分量（在磁场情况下）或切向分量（在电场情况下）基本上消失在 主要和次要结构之一。 第一电流或电荷分布被约束到初级结构的表面，并且第二电流或电荷分布被约束到二级结构的表面。 然后同时计算第一和第二电流或电荷分布，同时允许第一和第二电流或电荷分布同时观察约束，使得在第一区域中实现预定的磁场或电场，并且在一个区域上实现磁场或电场 预定边界的一侧基本为零。

公开(公告)号：US5689189A

公开(公告)日：1997-11-18

申请号：US638203

申请日：1996-04-26

申请人： Michael A. Morich ,  Labros S. Petropoulos ,  Hiroyuki Fujita ,  Shmaryu Shvartsman ,  Robert W. Brown

发明人： Michael A. Morich ,  Labros S. Petropoulos ,  Hiroyuki Fujita ,  Shmaryu Shvartsman ,  Robert W. Brown

IPC分类号： A61B5/055 ,  G01R33/34 ,  G01V3/00

CPC分类号： G01R33/341

摘要： A localized coil (30) is disposed in the temporally constant magnetic field of a magnetic resonance imaging system. The localized coil is designed in five steps: a static problem formulation step, a static current solution step, a discretization step, a current loop connection step, and a high frequency solution step. One radio frequency coil designed by this process to be carried on a circularly cylindrical former includes two coil sections (60, 62) disposed on opposite sides of the dielectric former. Each of the two coil sections includes a pair of inner loops (64.sub.1, 64.sub.2) disposed symmetrically relative to a z=0 plane of symmetry and a second pair of loops (68.sub.1, 68.sub.2) also disposed symmetrically about the plane of symmetry. To raise self-resonance frequency, the inner and outer loops are connected in parallel. The resonance frequency is fine-tuned with reactive elements (66.sub.1, 66.sub.2). To ensure balanced current flow between the two coil portions, the two portions are connected (78) in parallel.

摘要翻译： 局部线圈（30）设置在磁共振成像系统的时间上恒定的磁场中。 局部线圈设计有五个步骤：静态问题制定步骤，静态电流解决步骤，离散化步骤，电流环路连接步骤和高频解决步骤。 通过该工艺设计的一个射频线圈被承载在圆柱形成形器上，包括设置在电介体的相对侧上的两个线圈部分（60,62）。 两个线圈段中的每一个包括一对相对于z = 0对称平面对称设置的内环（641,642），以及也围绕对称平面对称设置的第二对环（681,682）。 为了提高自谐振频率，内环和外环并联。 谐振频率与无功元件（661,662）进行微调。 为了确保两个线圈部分之间的平衡电流流动，两个部分平行连接（78）。

公开(公告)号：US5545996A

公开(公告)日：1996-08-13

申请号：US303620

申请日：1994-09-09

申请人： Michael A. Morich ,  Labros S. Petropoulos

发明人： Michael A. Morich ,  Labros S. Petropoulos

IPC分类号： A61B5/055 ,  G01R33/34 ,  G01R33/385 ,  G01R33/421 ,  G01V3/00 ,  G01V3/14

CPC分类号： G01R33/385 ,  G01R33/3854 ,  G01R33/4215

摘要： Superconducting magnets (10) generate a temporally constant magnetic field through a bore (12). The bore, hence the superconducting magnets, have a length which is relatively short compared to its diameter, a length to diameter ratio of less than 1.0 to 1.5 and preferably 1:1. A gradient coil assembly (30) is disposed around the bore for generating gradient magnetic fields across the bore. With such a relatively short bore magnet, in the region in which the gradient field coil is disposed, the main magnetic field suffers non-uniformities including radial magnetic field components. When current pulses are fed through the windings of a primary gradient coil (32) and a secondary gradient coil (34), the currents interact in an unbalanced manner with the non-uniformities and radial components of the temporally constant magnetic field, causing a net force in axial and/or transverse directions. Additional windings (62, 72) are mounted adjacent the ends of the gradient coil, carrying current in an opposite direction to z and transverse gradient windings in order to produce a counterbalancing force such that the net and counterbalancing forces substantially cancel. In this manner, the gradient coil assembly is freed from the necessity of a substantial mechanical mountings and the vibration and distortion which large net forces can cause.

摘要翻译： 超导磁体（10）通过孔（12）产生时间上恒定的磁场。 因此，超导磁体的孔具有与其直径相比较小的长度，长径比小于1.0至1.5，优选地为1:1。 梯度线圈组件（30）设置在孔周围，用于产生穿过孔的梯度磁场。 在这种相对较短的孔径磁体中，在设置梯度场线圈的区域中，主磁场受到包括径向磁场分量在内的不均匀性的影响。 当电流脉冲馈送通过主梯度线圈（32）和次级梯度线圈（34）的绕组时，电流以不均衡的方式与时间上恒定的磁场的非均匀性和径向分量相互作用，从而产生网 在轴向和/或横向上的力。 附加的绕组（62,72）被安装在梯度线圈的端部附近，以与Z和横向梯度绕组相反的方向承载电流，以便产生平衡力，使得净和平衡力基本上消除。 以这种方式，梯度线圈组件不需要大量的机械安装以及大的净力可能引起的振动和变形。

公开(公告)号：US06946840B1

公开(公告)日：2005-09-20

申请号：US10093051

申请日：2002-03-07

申请人： Mark Xueming Zou ,  Labros S. Petropoulos ,  Joseph Murphy-Boesch ,  Pei Chan ,  Rony Thomas

发明人： Mark Xueming Zou ,  Labros S. Petropoulos ,  Joseph Murphy-Boesch ,  Pei Chan ,  Rony Thomas

IPC分类号： G01R33/3415 ,  G01V3/00

CPC分类号： G01R33/3415

摘要： A MRI array coil includes a plurality of first coils in a receive coil array and a plurality of second coils in a transmit coil array. The receive coil array and the transmit coil array are electrically disjoint.

摘要翻译： MRI阵列线圈包括接收线圈阵列中的多个第一线圈和发射线圈阵列中的多个第二线圈。 接收线圈阵列和发射线圈阵列是电不相交的。

公开(公告)号：US6049207A

公开(公告)日：2000-04-11

申请号：US200659

申请日：1998-11-25

申请人： Labros S. Petropoulos

发明人： Labros S. Petropoulos

IPC分类号： A61B5/055 ,  G01R33/421 ,  G01V3/00

CPC分类号： G01R33/4215 ,  G01R33/421

摘要： A method of designing a shielded gradient coil assembly (22) for magnetic resonance imaging systems is provided. The gradient coil structure comprises two sets of primary gradient coils (60, 62) and a single set of a shielded (screening) coils (64). This configuration is suitable for MR applications utilizing a double duty gradient configuration including a high-efficiency primary coil set that enhances the performance of ultra fast MR sequencing while minimizing the dB/dt and eddy current effects, and including a low-efficiency primary coil set having a high-quality gradient field that is suitable for conventional imaging applications with inherently low dB/dt and eddy current levels. In addition, a minimum inductance/energy algorithm assists in the design of the two primary and the one secondary gradient sets.

摘要翻译： 提供了一种设计用于磁共振成像系统的屏蔽梯度线圈组件（22）的方法。 梯度线圈结构包括两组初级梯度线圈（60,62）和一组屏蔽（屏蔽）线圈（64）。 该配置适用于利用双重占空比梯度配置的MR应用，包括高效率初级线圈组，其提高超快速MR测序的性能，同时最小化dB / dt和涡流效应，并且包括低效率初级线圈组 具有高质量的梯度场，适用于具有固有的低dB / dt和涡流电平的传统成像应用。 此外，最小电感/能量算法有助于两个主要和一个二次梯度集的设计。

公开(公告)号：US06975115B1

公开(公告)日：2005-12-13

申请号：US10164664

申请日：2002-06-07

申请人： Hiroyuki Fujita ,  Pei H. Chan ,  Dashen Chu ,  Joseph Murphy-Boesch ,  Labros S. Petropoulos ,  Mark Xueming Zou

发明人： Hiroyuki Fujita ,  Pei H. Chan ,  Dashen Chu ,  Joseph Murphy-Boesch ,  Labros S. Petropoulos ,  Mark Xueming Zou

IPC分类号： G01R33/3415 ,  G01V3/00

CPC分类号： G01R33/3415

摘要： A partially parallel acquisition RF coil array for imaging a sample includes at least a first, a second and a third coil adapted to be arranged circumambiently about the sample and to provide both contrast data and spatial phase encoding data.

摘要翻译： 用于对样本进行成像的部分平行采集RF线圈阵列包括至少第一，第二和第三线圈，其适于围绕样本周边布置并提供对比度数据和空间相位编码数据。