公开(公告)号：US4841248A

公开(公告)日：1989-06-20

申请号：US86277

申请日：1987-08-17

申请人： Mehrdad Mehdizadeh ,  John L. Patrick ,  George J. Misic

发明人： Mehrdad Mehdizadeh ,  John L. Patrick ,  George J. Misic

IPC分类号： G01R33/34 ,  G01R33/341 ,  G01R33/36

CPC分类号： G01R33/34046 ,  G01R33/341 ,  G01R33/36 ,  G01R33/3628

摘要： Magnets (12) create a main magnetic field along a z-axis through an image region. A localized coil (D) is disposed in the image region at least to receive magnetic resonance signals from nuclei of the subject which have been induced to resonance. The localized coil includes an inner conductor (30), preferably a plate, which defines a current path extending along the z-axis. The inner conductor is mounted closely adjacent and parallel to a surface of the subject. An outer conductor (32), preferably also a plate, is mounted parallel to but further from the subject than the first conductor. A connecting member (34) interconnects a first end of the inner and outer conductors and is disposed perpendicular to the z-axis. A matching circuit (36) including capacitors (50) which define the resonant frequency of the coil are connected adjacent second ends of the inner and outer conductors. Because the nuclei induced to resonance within the z-axis magnetic field generate magnetic resonance components in the x-y plane, an optimal coupling is achieved to reception of the magnetic resonance signals.

摘要翻译： 磁体（12）通过图像区域沿z轴产生主磁场。 至少在图像区域中设置局部线圈（D）以接收已经被诱导到共振的受试者的核的磁共振信号。 局部线圈包括限定沿z轴延伸的电流路径的内导体（优选为板）。 内部导体紧密地安装在主体表面上并平行。 外导体（32），优选地也是板，与第一导体平行但是远离被检体安装。 连接构件（34）将内导体和外导体的第一端互连并且垂直于z轴布置。 包括限定线圈的谐振频率的电容器（50）的匹配电路（36）被连接在内导体和外导体的第二端附近。 因为在z轴磁场内引起谐振的核在x-y平面中产生磁共振分量，所以实现了接收磁共振信号的最佳耦合。

公开(公告)号：US4833429A

公开(公告)日：1989-05-23

申请号：US194974

申请日：1988-05-17

申请人： Hanan Keren ,  Itzchak Linenberg

发明人： Hanan Keren ,  Itzchak Linenberg

IPC分类号： G01R33/341

CPC分类号： G01R33/3678

摘要： A quadrature coil combiner for phase shifting the pulses and signals of a quadrature coil system used in magnetic resonance (MR) systems to selectively combine or cancel the pulses and signals transmitted and received. The combiner comprises a first and a second conductor for coupling a first and a second coil respectively of the quadrature coil system to a transmit-receive circuit of the MR system. The first conductor comprises an insertable .pi./2 radian delay. The second conductor includes a fixed .pi./2 radian delay. At least one of either the fixed delay or the insertable delay is a quarter wavelength cable whereby active elements are minimized.

摘要翻译： 一种正交线圈组合器，用于对在磁共振（MR）系统中使用的正交线圈系统的脉冲和信号进行相移，以选择性地组合或取消发射和接收的脉冲和信号。 组合器包括用于将正交线圈系统的第一和第二线圈耦合到MR系统的发射 - 接收电路的第一和第二导体。 第一导体包括可插入的π/ 2弧度延迟。 第二导体包括固定的pi / 2弧度延迟。 固定延迟或可插入延迟中的至少一个是四分之一波长的电缆，由此有源元件被最小化。

公开(公告)号：US4816765A

公开(公告)日：1989-03-28

申请号：US117118

申请日：1987-11-04

申请人： Eddy B. Boskamp

发明人： Eddy B. Boskamp

IPC分类号： G01R33/32 ,  A61B5/055 ,  A61B10/00 ,  G01R33/34 ,  G01R33/341 ,  G01R33/20

CPC分类号： G01R33/3678 ,  G01R33/341

摘要： The detection coil of a magnetic resonance imaging apparatus comprises a stack of two coils with locally mutually perpendicularly directed B Fields. The first coil is formed as a butterfly coil having a B field extending parallel to the plane of the coil, the second coil being formed by a single flat coil having a B field extending transversely of the plane of the coil. The coils are arranged in a fixed mutual orientation so that for each of the coils reciprocally applied fluxes are always compensated for.

公开(公告)号：US4791372A

公开(公告)日：1988-12-13

申请号：US86368

申请日：1987-08-17

申请人： Gregory L. Kirk ,  Jeffrey D. Mewborne ,  David M. Parish

发明人： Gregory L. Kirk ,  Jeffrey D. Mewborne ,  David M. Parish

IPC分类号： A61B10/00 ,  A61B5/055 ,  G01R33/34 ,  G01R33/341 ,  G01R33/343 ,  G01R33/20

CPC分类号： G01R33/341 ,  G01R33/343 ,  G01R33/34084

摘要： A pickup coil for magnetic resonance imaging (MRI) includes a single thin metal copper sheet which is covered with cloth-like material with the interior of the two ends of the coil being covered with VELCRO-type connective material so that they adhere together. Thus, this provides a conforming fit to various specimens of varying diameters and configurations. The two ends of the coil are held by and inserted in a capacitive tuning unit which compensates for the resistive loading caused by the specimen and also for implementing the needed resonance condition.

公开(公告)号：US4751464A

公开(公告)日：1988-06-14

申请号：US45403

申请日：1987-05-04

申请人： James F. Bridges

发明人： James F. Bridges

IPC分类号： H01P7/06 ,  A61B5/055 ,  G01R33/34 ,  G01R33/341 ,  G01R33/343 ,  G01R33/345 ,  G01R33/20

CPC分类号： G01R33/3678 ,  G01R33/343 ,  G01R33/34007

摘要： A cavity resonator suitable for use in a high-speed nuclear magnetic resonance (NMR) imaging device comprises a plurality of transmission lines aligned parallel to a common axis and magnetically coupled to produce an essentially uniform dipole magnetic field perpendicular to the axis. The transmission lines are two conductor lines, with the first conductors being arranged inwardly of a second conductor common to all lines. The common conductor is symmetrically arranged about the axis of the resonator and constitutes a shield to contain the magnetic field within the cavity. The plurality of transmission lines are conductively isolated from each other but spaced in sufficiently close proximity to each to provide for strong mutual magnetic coupling amongst all transmission lines. A single inductive coupling loop may be provided for driving the resonator with a linearly polarized magnetic field and for receiving NMR information from the resonator. The use of a pair of inductive coupling loops spaced 90.degree. about the resonator axis provides a circularly polarized magnetic field within the resonator when the loops are driven in electrical phase quadrature. Two inductive coupling loops for each imaging mode may be provided to eleminate undesirable modes and hence distortion in the NMR image. The common conductor and the longitudinal ends of the resonator are provided with slits designed to allow the changing high-speed gradient magnetic fields to fill the imaging volume fast enough to accomplish high-speed imaging.

公开(公告)号：US4739271A

公开(公告)日：1988-04-19

申请号：US757073

申请日：1985-07-19

申请人： Axel Haase

发明人： Axel Haase

IPC分类号： G01R33/341 ,  G01R33/36 ,  G01R33/20

CPC分类号： G01R33/3657 ,  G01R33/341

摘要： A circuit arrangement is described for preventing a reaction of a coil on an external high-frequency field of predetermined frequency containing the coil due to a current induced by the field in the coil for a multiple-coil probe of a nuclear magnetic resonance apparatus wherein the coil is coupled via a high-frequency line of predetermined characteristic impedance to a switching element and a circuit unit cooperating with the coil. The electrical length of the high-frequency line between the coil and the switching element is so dimensioned that any undesired reaction of an inactive coil on the other coil(s) is eliminated.

摘要翻译： 描述了一种电路装置，用于防止由于由核磁共振装置的多线圈探针的线圈中的场引起的包含线圈的预定频率的外部高频场的线圈的反应，其中， 线圈经由预定特性阻抗的高频线耦合到开关元件和与线圈配合的电路单元。 线圈和开关元件之间的高频线的电长度的尺寸被确定为消除了在另一个线圈上的无效线圈的任何不期望的反应。

公开(公告)号：US4684895A

公开(公告)日：1987-08-04

申请号：US762306

申请日：1985-08-05

申请人： George J. Misic

发明人： George J. Misic

IPC分类号： A61B5/055 ,  A61B10/00 ,  G01R33/341 ,  G01R33/36 ,  G01R33/20

CPC分类号： G01R33/3678 ,  G01R33/3621 ,  G01R33/3614

摘要： In a magnetic resonance imager or other spectrometer, an interface (D) selectively connects quadrature probe coils (E) with a transmitter (C) and with a receiver (F). The interface includes a first RF switch (10), such as a first PIN diode (12) which has a low radio frequency impedance state for passing transmitted radio frequency signals to the probe coils and a high radio frequency impedance state for blocking the passage of radio frequency signals to the probe coils. A quarter wave length cable (20) or the equivalent is connected between the probe coils to shift the phase of the radio frequency signals 90 degrees. A second radio frequency switch (40) includes a second quarter wave length cable (42) and a second pin diode (44) which selectively pass and block radio frequency signals from passing between the probe coils and the receiver. A third pin diode (52) selectively connects a third quarter wave length cable (54) with ground to provide a band pass filter in the transmit mode and causes the third quarter wave length cable to be connected to ground through a fourth quarter wave length cable (60) in the receive mode to provide a band stop filter. A control (G) selectively biases the PIN diodes between their conductive and non-conductive states to establish the transmit and receive modes.

摘要翻译： 在磁共振成像仪或其他光谱仪中，接口（D）选择性地将正交探针线圈（E）与发射器（C）和接收器（F）连接。 该接口包括第一RF开关（10），例如第一PIN二极管（12），其具有用于将发射的射频信号传递到探针线圈的低射频阻抗状态，以及高的射频阻抗状态以阻止 射频信号到探头线圈。 四分之一波长电缆（20）或等效物连接在探针线圈之间，将射频信号的相位90度相移。 第二射频开关（40）包括第二四分之一波长电缆（42）和第二pin二极管（44），其选择性地传递和阻止射频信号在探针线圈和接收器之间通过。 第三pin二极管（52）选择性地将第三四分之一波长电缆（54）与地连接，以在发射模式下提供带通滤波器，并且使第三四分之一波长电缆通过第四四分之一波长电缆 （60）处于接收模式以提供带阻滤波器。 控制器（G）选择性地偏置PIN二极管在它们的导通状态和非导通状态之间以建立发射和接收模式。

公开(公告)号：US4636730A

公开(公告)日：1987-01-13

申请号：US641540

申请日：1984-08-16

申请人： Paul A. Bottomley

发明人： Paul A. Bottomley

IPC分类号： G01R33/48 ,  A61B5/055 ,  A61B10/00 ,  G01N27/30 ,  G01R33/32 ,  G01R33/341 ,  G01R33/36 ,  G01R33/483 ,  G01R33/20

CPC分类号： G01R33/3635 ,  G01R33/34007 ,  G01R33/341 ,  G01R33/3415 ,  G01R33/422 ,  G01R33/4831 ,  Y10S505/844

摘要： An NMR spectroscopy body probe is comprised of at least one surface coil, each coil having at least one turn and positioned adjacent to a first surface of an insulative member; an electric-field-reducing shield is fabricated upon the other surface of the relatively flexible substrate. The shield surface of the probe is to be positioned closest to the sample. A plurality of surface coil-bearing substrates can be stacked, one adjacent to the other with the planes thereof substantially parallel to each other and to the plane of the electric-field shield, and with each individual surface coil being separately tunable to a different nuclei species resonance frequency. Each surface coil can be utilized for both transmission and reception, or can be used for only reception of the re-radiated signal from the sample, with a separate excitation coil being provided with a radius substantially greater than the average radius of the (receiver) surface coil and positioned in the plane of any of the at least one receiving surface coils.

摘要翻译： NMR光谱体探针由至少一个表面线圈组成，每个线圈具有至少一个匝并且邻近绝缘构件的第一表面定位; 在相对柔性的衬底的另一个表面上制造电场减小屏蔽。 探针的屏蔽表面应位于最靠近样品的位置。 多个表面线圈承载基板可以堆叠在一起，彼此相邻，其平面基本上彼此平行并且与电场屏蔽的平面相互间隔，并且每个单独的表面线圈可单独调节到不同的核 物种共振频率。 每个表面线圈可以用于发送和接收，或者可以仅用于接收来自样本的再辐射信号，其中单独的励磁线圈设置有大致大于（接收器）的平均半径的半径， 表面线圈并定位在所述至少一个接收表面线圈中的任何一个的平面中。

公开(公告)号：US4486709A

公开(公告)日：1984-12-04

申请号：US443607

申请日：1982-11-22

申请人： Max R. Bendall

发明人： Max R. Bendall

IPC分类号： G01R33/341 ,  G01R33/465 ,  G01R33/48 ,  G01R33/08

CPC分类号： G01R33/446 ,  G01R33/341 ,  G01R33/465

摘要： In a pulsed nuclear magnetic resonance method of analysis, in which a single radiofrequency pulse is applied using an irradiation coil which provides an inhomogeneous radiofrequency field across the sample volume, the inhomogeneity of this field ensures that some sample regions experience a radiofrequency pulse which is closer to a .pi./2 pulse angle than for other regions, resulting in a larger signal intensity from the former regions as compared to the latter. If a second pulse is applied after the first, prior to acquisition of the signal, and if the phase of this pulse is alternated through the four phases: 0.degree., 90.degree., 180.degree. and 270.degree., during a series of transients, then, provided the receiver phase is changed by 180.degree. when the second pulse phase is changed by 90.degree., the signal intensity will accumulate from regions where the second pulse angle is .pi. radians and there will be discrimination against regions where the second pulse angle differs markedly from .pi. radians. This discrimination towards certain sample regions can be improved by adding further pulses after the second pulse provided the phase of each additional pulse is alternated through all four 90.degree. phase shifts, during a series of transients, independently of the phase alternation of the other pulses, and provided that for each individual 90.degree. phase shift, the receiver phase is changed by 180.degree.. In its simplest form, such a series of pulses may be represented by .theta.;(2.theta.[.+-.x,.+-.y]).sub.n indicating n phase alternated pulses additional to the first excitation pulse, where these additional pulses are twice as long as the first pulse.

摘要翻译： 在脉冲核磁共振分析方法中，使用在样品体积上提供不均匀的射频场的照射线圈施加单个射频脉冲，该场的不均匀性确保了一些采样区域经历更接近的射频脉冲 与其他区域相比为π/ 2脉冲角，导致与后者相比较，来自前一个区域的信号强度较大。 如果在第一次施加第二个脉冲之后，在采集信号之前，如果在一系列瞬变期间该脉冲的相位在0°，90°，180°和270°四个相位之间交替，则 只要第二个脉冲相位改变90°，接收机相位改变180°，信号强度将从第二个脉冲角度为pi弧度的区域累积，并且将区分第二个脉冲角度明显不同的区域 从pi弧度。 通过在第二脉冲之后添加进一步脉冲，可以改善对某些采样区域的区分，只要每一个附加脉冲的相位在一系列瞬变期间在所有四个90°相移之间交替，而与其它脉冲的相位交替无关， 并且对于每个单独的90°相移，接收器相位改变180°。 在其最简单的形式中，这样的一系列脉冲可以由θ表示;（2θ[+/- x，+ / - y]）n表示第一激励脉冲附加的n相交变脉冲，其中这些附加脉冲是两倍 只要第一脉冲。

公开(公告)号：US11567152B2

公开(公告)日：2023-01-31

申请号：US17383020

申请日：2021-07-22

申请人： SYNAPTIVE MEDICAL INC.

发明人： Ian Robert Oliphant Connell ,  Gilbert Thevathasan ,  William Wai-Leung Lau ,  Alexander Gyles Panther

IPC分类号： G01R31/00 ,  G01R33/34 ,  A61B5/055 ,  G01R33/341

摘要： A head coil assembly includes a housing with a lower portion, an upper portion, a left portion, and a right portion, wherein each portion includes two or more radio-frequency (RF) coils, wherein the portions are sized and shaped to adjustably conform to a curvature of the subject's head for magnetic resonance (MR) imaging of the subject's head placed inside the housing, wherein the portions are operable to transition from an open position where the portions are sufficiently apart from each other to a closed position where the portions are adjusted to tighten a wrap around the subject's head along the curvature, and wherein the two or more RF coils in each portion are disposed in such manner that when the portions are operated to transition from the open position to the closed position, the RF coils of each portion remain decoupled to each other even along edges of each portion.