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    Inherently de-coupled sandwiched solenoidal array coil
    2.
    发明授权
    Inherently de-coupled sandwiched solenoidal array coil 有权
    固有的去耦合夹层螺线管阵列线圈

    公开(公告)号：US06493572B1

    公开(公告)日：2002-12-10

    申请号：US09408506

    申请日：1999-09-30

    申请人： Sunyu Su ,  Leon Kaufman ,  Mitsuaki Arakawa ,  Joseph W. Carlson

    发明人： Sunyu Su ,  Leon Kaufman ,  Mitsuaki Arakawa ,  Joseph W. Carlson

    IPC分类号： A61B5055

    CPC分类号： G01R33/3415

    摘要： An inherently de-coupled sandwiched solenoidal array coil (SSAC) is disclosed for use in receiving nuclear magnetic resonance (NMR) radio frequency (RF) signals in both horizontal and vertical-field magnetic resonance imaging (MRI) systems. In its most basic configuration, the SSAC comprises two coaxial RF receive coils. The first coil of the array has two solenoidal (or loop) sections that are separated from one another along a common axis. The two sections are electrically connected in series but the conductors in each section are wound in opposite directions so that a current through the coil sets up a magnetic field of opposite polarity in each section. The second coil of the SSAC is disposed (“sandwiched”) between the two separated solenoidal sections of the first coil in a region where the combined opposing magnetic fields cancel to become a null. Due to the winding arrangement and geometrical symmetry, the receive coils of the array become electromagnetically “de-coupled” from one another while still maintaining their sensitivity toward receiving NMR signals. The multiple coil array arrangement also allows for selecting between a larger or smaller field-of-view (FOV) to avoid image fold-over problems without time penalty in image data acquisition. Alternative embodiments are disclosed which include unequal constituent coil diameters, unequal constituent coil windings, non-coaxial coil configurations, a three-coil quadrature detection (QD) SSAC arrangement, multiple SSAC arrangements, and optimized SSAC configurations for breast imaging in both horizontal and vertical-field MRI systems.

    摘要翻译： 公开了一种固有的去耦合的夹层螺线管阵列线圈（SSAC），用于在水平和垂直场磁共振成像（MRI）系统中接收核磁共振（NMR）射频（RF）信号。 在其最基本的配置中，SSAC包括两个同轴RF接收线圈。 阵列的第一个线圈具有沿公共轴彼此分离的两个螺线管（或环）部分。 两个部分串联电连接，但每个部分中的导体沿相反的方向缠绕，使得通过线圈的电流在每个部分中建立相反极性的磁场。 SSAC的第二线圈在组合的相对磁场取消为零的区域中被布置（“夹持”在第一线圈的两个分离的螺线管部分之间）。 由于绕组布置和几何对称性，阵列的接收线圈彼此电磁“去耦合”，同时仍然保持对接收NMR信号的灵敏度。 多线圈阵列布置还允许在更大或更小的视场（FOV）之间进行选择，以避免图像折叠问题，而在图像数据采集中没有时间损失。 公开了包括不等构成线圈直径，不相等的构成线圈绕组，非同轴线圈配置，三线圈正交检测（QD）SSAC布置，多个SSAC布置以及用于乳腺成像在水平和垂直方向上的优化SSAC配置的替代实施例 场MRI系统。

    Open architecture iron core electromagnet for MRI using superconductive winding
    4.
    发明授权
    Open architecture iron core electromagnet for MRI using superconductive winding 失效
    使用超导绕组开放架构用于MRI的铁芯电磁铁

    公开(公告)号：US5250901A

    公开(公告)日：1993-10-05

    申请号：US789041

    申请日：1991-11-07

    申请人： Leon Kaufman ,  Joseph W. Carlson

    发明人： Leon Kaufman ,  Joseph W. Carlson

    IPC分类号： G01R33/38 ,  G01R33/383 ,  G01R33/3875 ,  G01R33/20

    CPC分类号： G01R33/383 ,  G01R33/3806 ,  G01R33/3875

    摘要： A high T.sub.c superconductive electromagnet winding is advantageously employed as part of an MRI magnet structure having a pair of magnetically permeable poles opposingly disposed about the patient imaging volume. The magnetic circuit is otherwise completed by a magnetically permeable yoke structure having plural open apertures for easy access to the patient imaging volume. Still further advantage can be had by asymmetrically disposing a single superconductive electromagnet winding with respect to the patient image volume thereby eliminating the need for more than one cryostat. When high T.sub.c superconductive electromagnetic windings are utilized, a non-conductive composite cryostat may also be used to further reduce spurious eddy current fields. When an asymmetric single high T.sub.c superconductive electromagnet coil is utilized, an asymmetric electromagnet shim winding may also be employed so as to further increase the magnetic field homogeneity within what is now an asymmetrically located patient imaging volume within the air gap of the magnet structure.

    摘要翻译： 有利地采用高Tc超导电磁铁绕组作为具有相对设置在患者成像体积周围的一对导磁极的MRI磁体结构的一部分。 否则，磁路可以通过具有多个开放孔径的磁性可透过的磁轭结构来完成，以容易地接近患者成像体积。 可以通过相对于患者图像体积不对称地布置单个超导电磁铁绕组而进一步的优点，从而不需要多于一个的低温恒温器。 当使用高Tc超导电磁绕组时，也可以使用非导电复合低温恒温器来进一步减少杂散涡流场。 当使用非对称单高Tc超导电磁线圈时，也可以采用非对称电磁铁垫片绕组，以便进一步增加磁体均匀性，现在在磁体结构的气隙内的不对称位置的患者成像体积内。

    Gradient driver control in magnetic resonance imaging
    5.
    发明授权
    Gradient driver control in magnetic resonance imaging 失效
    磁共振成像中梯度驱动控制

    公开(公告)号：US5227728A

    公开(公告)日：1993-07-13

    申请号：US786828

    申请日：1991-11-01

    申请人： Leon Kaufman ,  Joseph W. Carlson ,  Richard Gran

    发明人： Leon Kaufman ,  Joseph W. Carlson ,  Richard Gran

    IPC分类号： A61B5/055 ,  G01R33/12 ,  G01R33/381 ,  G01R33/385 ,  G01R33/389

    CPC分类号： G01R33/385 ,  G01R33/389

    摘要： Electromagnet coil driving circuitry in a magnetic resonance imaging system is modified to include a flux-driven closed-loop real-time feedback control. The result is more accurate and efficient control of the net actual gradient flux generated by the coil even in the presence of magnetic circuit materials exhibiting hysteresis effects and/or electrical conductors giving rise to eddy current effects. Such driver control can be used to simultaneously correct the magnetic flux changes induced by environmental, ambient or other outside disturbances affecting the net magnetic field within a patient imaging volume of a magnetic resonance imaging system.

    摘要翻译： 磁共振成像系统中的电磁线圈驱动电路被修改为包括磁通驱动的闭环实时反馈控制。 结果是即使在存在导致涡流效应的磁滞效应的磁路材料和/或电导体的情况下，线圈产生的净实际梯度通量的更精确和有效的控制。 可以使用这样的驱动器控制来同时校正由影响磁共振成像系统的患者成像体积内的净磁场的环境，环境或其它外部干扰引起的磁通量变化。

    MRI magnet with robust laminated magnetic circuit member and method of making same
    7.
    发明授权
    MRI magnet with robust laminated magnetic circuit member and method of making same 失效
    具有坚固的层叠磁路元件的MRI磁体及其制造方法

    公开(公告)号：US5317297A

    公开(公告)日：1994-05-31

    申请号：US141701

    申请日：1993-10-26

    申请人： Leon Kaufman ,  Joseph W. Carlson ,  Shigemasu Okada ,  Shigeo Hashimoto

    发明人： Leon Kaufman ,  Joseph W. Carlson ,  Shigemasu Okada ,  Shigeo Hashimoto

    IPC分类号： A61B5/055 ,  G01R33/20 ,  G01R33/38 ,  G01R33/381 ,  G01R33/383 ,  G01R33/385 ,  H01F3/00

    CPC分类号： B82Y15/00 ,  G01R33/383 ,  G01R33/385

    摘要： An MRI magnet member (e.g., a pole piece or tip) is laminated using relatively large bar-shaped laminations instead of the usual thin sheet material. One or more layers of such bar-shaped laminations are arrayed with small insulating gaps into which a low loss insulating liquid filler material is flowed and then cured to a hardened solid state. This simultaneously produces insulated pole tip laminations which have been robustly integrated together into a unitary structure. The resulting robust laminated pole tip is relatively easy to manufacture and is also capable of withstanding rather large magnetic forces and maintaining relatively uniform magnetic field distribution within an MRI imaging region while yet providing providing sufficient eddy current reduction so as to efficiently permit rapidly changing magnetic gradient coil currents to be established.

    摘要翻译： 使用相对较大的棒状叠片而不是通常的薄片材料层叠MRI磁体构件（例如，极片或尖端）。 这种棒状叠片的一层或多层排列有小的绝缘间隙，低损失绝缘液体填充材料流入其中，然后固化至硬化固体状态。 这同时产生绝缘极尖叠片，它们已经牢固地集成在一起成为一体的结构。 所得到的坚固的层叠极尖相对容易制造，并且还能够承受相当大的磁力并且在MRI成像区域内保持相对均匀的磁场分布，同时还提供足够的涡流减少以便有效地允许快速变化的磁梯度 线圈电流要建立。

    RF coil array for vertical field MRI
    9.
    发明授权
    RF coil array for vertical field MRI 有权
    用于垂直场MRI的RF线圈阵列

    公开(公告)号：US06377836B1

    公开(公告)日：2002-04-23

    申请号：US09250603

    申请日：1999-02-17

    申请人： Mitsuaki Arakawa ,  Joseph W. Carlson ,  Leon Kaufman ,  James V. Reveaux

    发明人： Mitsuaki Arakawa ,  Joseph W. Carlson ,  Leon Kaufman ,  James V. Reveaux

    IPC分类号： A61B5055

    CPC分类号： G01R33/34053 ,  A61B5/055 ,  A61B5/7257 ,  G01R33/34069 ,  G01R33/3415 ,  G01R33/3806

    摘要： An RF coil array arrangement for enhanced magnetic resonance imaging of the breast or spine regions of prone and supine patients within a vertically oriented B0 field is disclosed. Several RF coil array embodiments are disclosed that provide for both generating a nuclei nutation field pulse and acquiring nuclear magnetic resonance signals when functioning in an MRI apparatus environment that employs a vertical main magnetic field. A coil array may include one or more RF coils that are intended to be oriented such that their primary B field direction(s) are perpendicular to the vertical magnetic field of the MRI apparatus. Each coil array may further include one or more single loop or solenoidal coil(s) that are oriented having their central or longitudinal axis aligned parallel to the vertical main magnetic field so as to make advantageous use of non-axial field components associated with the coil(s) to further generate and receive desired NMR signal components.

    摘要翻译： 公开了用于在垂直取向的B0场内对倾斜和仰卧患者的乳房或脊柱区域进行增强的磁共振成像的RF线圈阵列装置。 公开了几个RF线圈阵列实施例，其提供了当在使用垂直主磁场的MRI装置环境中起作用时，产生核心章动场脉冲和获取核磁共振信号。 线圈阵列可以包括一个或多个RF线圈，其旨在被定向成使得它们的主B场方向垂直于MRI设备的垂直磁场。 每个线圈阵列还可以包括一个或多个单个环路或螺线管线圈，其被定向成使其中心轴或纵向轴线平行于垂直主磁场排列，以便有利地使用与线圈相关的非轴向场分量 以进一步产生和接收期望的NMR信号分量。

    Discrete step remotely adjustable matching circuit for MRI RF coils
    10.
    发明授权
    Discrete step remotely adjustable matching circuit for MRI RF coils 失效
    用于MRI RF线圈的离散步距可调匹配电路

    公开(公告)号：US5670881A

    公开(公告)日：1997-09-23

    申请号：US599071

    申请日：1996-02-09

    申请人： Mitsuaki Arakawa ,  John G. van Heteren ,  Joseph W. Carlson ,  Leon Kaufman ,  Einar Tapio

    发明人： Mitsuaki Arakawa ,  John G. van Heteren ,  Joseph W. Carlson ,  Leon Kaufman ,  Einar Tapio

    IPC分类号： A61B5/055 ,  G01R33/36 ,  G01R33/34 ,  H01P5/08

    CPC分类号： G01R33/3628 ,  H03J2200/10

    摘要： An RF coil tuning circuit is disclosed in which two banks of parallel capacitive branches are provided. Each capacitive branch includes a fixed value capacitor, a relay and a PIN diode connected in series. An impedance of the tuning circuit is adjusted to the optimum VSWR=1 condition by first switching the eight PIN diodes to learn which open/closed condition applies the fixed value capacitors in the optimum combination. Then, the PIN diodes are all closed and the optimum combination is applied using the open/closed states of the relays.

    摘要翻译： 公开了一种RF线圈调谐电路，其中提供两组并联电容分支。 每个电容分支包括固定值电容器，继电器和串联的PIN二极管。 通过首先切换八个PIN二极管来调整调谐电路的阻抗到最佳VSWR = 1状态，以了解哪个开/关条件以最佳组合施加固定值电容器。 然后，PIN二极管全部关闭，并且使用继电器的开/关状态来应用最佳组合。