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    MRI using auxiliary insert gradient coil to produce intense auxiliary magnetic gradient pulses
    1.
    发明授权
    MRI using auxiliary insert gradient coil to produce intense auxiliary magnetic gradient pulses 失效
    MRI使用辅助插入梯度线圈产生强烈的辅助磁梯度脉冲

    公开(公告)号：US5235279A

    公开(公告)日：1993-08-10

    申请号：US837317

    申请日：1992-02-19

    申请人： Leon Kaufman ,  Joseph W. Carlson ,  Hector E. Avram

    发明人： Leon Kaufman ,  Joseph W. Carlson ,  Hector E. Avram

    IPC分类号： A61B5/055 ,  G01R33/34 ,  G01R33/381 ,  G01R33/385 ,  G01R33/389

    CPC分类号： G01R33/385

    摘要： An auxiliary insert MRI gradient coil is used to produce intense auxiliary magnetic gradient pulses during MRI sequences to improve MRI system performance. Although the auxiliary gradient coil may be of considerably reduced dimensions, thus, having considerably reduced uniformity, linearity and/or reproducibility than standard MRI gradient coils, coordinated use of both the regular MRI gradient coils and the auxiliary gradient coil can produce considerably enhanced MRI system performance in certain applications. Such auxiliary magnetic gradient coil may be used, for example, to provide spoiler pulses between MRI spin echo subsequences, as diffusion gradient pulses in diffusion MRI studies or as the oscillating gradient used to form successive gradient echoes in echo planar imaging.

    摘要翻译： 辅助插入MRI梯度线圈用于在MRI序列期间产生强烈的辅助磁梯度脉冲，以改善MRI系统性能。 虽然辅助梯度线圈可能具有相当大的减小的尺寸，因此，与标准MRI梯度线圈相比，具有显着降低的均匀性，线性和/或再现性，协调使用常规MRI梯度线圈和辅助梯度线圈可以产生显着增强的MRI系统 在某些应用中的性能。 例如，这种辅助磁梯度线圈可以用于在MRI自旋回波子序列之间提供扰流脉冲，作为扩散MRI研究中的扩散梯度脉冲或用作在回波平面成像中形成连续梯度回波的振荡梯度。

    Inherently de-coupled sandwiched solenoidal array coil
    3.
    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
    5.
    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
    6.
    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
    8.
    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。