NOISE MATCHING IN COUPLET ANTENNA ARRAYS
    1.
    发明申请
    NOISE MATCHING IN COUPLET ANTENNA ARRAYS 有权
    耦合天线阵列噪声匹配

    公开(公告)号:US20120019250A1

    公开(公告)日:2012-01-26

    申请号:US13258612

    申请日:2010-03-26

    IPC分类号: G01R33/36 H01Q1/50 G01R33/34

    摘要: The invention relates to a system comprising an array of two or more receiving antennas (11, 12, 13) for receiving RF signals, each receiving antenna being connected, via a matching network (19, 20, 21), to a low-noise amplifier (22, 23, 24) presenting an input impedance to the matching network (19, 20, 21), each chain consisting of a receiving antenna (11, 12, 13), a matching network (19, 20, 21) and a low-noise amplifier (22, 23, 24) constituting a part of a receiving channel of the system, the matching networks (19, 20, 21) transforming optimum impedances of the low-noise amplifiers (22, 23, 24), the optimum impedances providing optimum noise performance of the low-noise amplifiers (22, 23, 24), wherein each receiving channel comprises at least one switchable impedance (28, 29, 30) at the input of each low-noise amplifier (22, 23, 24) for switching the input impedance as presented to each matching network (19, 20, 21) to a value being the complex conjugate of the optimum impedance of the respective low-noise amplifier (22, 23, 24). The system is arranged to perform an optimization procedure comprising the following steps: a) switching the input impedance presented to the matching network (19, 20, 21) in each receiving channel to the complex conjugate of the optimum impedance of the respective low-noise amplifier (22, 23, 24); b) receiving RF signals via the receiving antennas (11, 12, 13); c) forming a weighted sum of the signal power of the received RF signals; d) modifying the matching networks (19, 20, 21) of all receiving channels so as to find an optimum matching condition by maximizing the weighted power sum; c) switching the input impedance in each receiving channel back to a value for regular operation of the system.

    摘要翻译: 本发明涉及一种系统,其包括用于接收RF信号的两个或更多个接收天线(11,12,13)的阵列,每个接收天线经由匹配网络(19,20,21)被连接到低噪声 放大器(22,23,24)向匹配网络(19,20,21)呈现输入阻抗,每条链由接收天线(11,12,13),匹配网络(19,20,21)和 构成系统的接收信道的一部分的低噪声放大器(22,23,24),匹配网络(19,20,21)对低噪声放大器(22,23,24)的最佳阻抗进行变换, 所述最佳阻抗提供所述低噪声放大器(22,23,24)的最佳噪声性能,其中每个接收通道包括在每个低噪声放大器(22,23,24)的输入处的至少一个可切换阻抗(28,29,30) 23,24),用于将呈现的输入阻抗切换到每个匹配网络(19,20,21),其值为最佳阻抗o的复共轭 f各个低噪声放大器(22,23,24)。 该系统被布置为执行优化过程,该过程包括以下步骤:a)将呈现给每个接收信道中的匹配网络(19,20,21)的输入阻抗切换到相应低噪声的最佳阻抗的复共轭 放大器(22,23,24); b)经由所述接收天线(11,12,13)接收RF信号; c)形成所接收的RF信号的信号功率的加权和; d)修改所有接收信道的匹配网络(19,20,21),以便通过最大化加权功率和来找到最佳匹配条件; c)将每个接收通道中的输入阻抗切换回系统的常规操作的值。

    Detuning a radio-frequency coil
    2.
    发明授权
    Detuning a radio-frequency coil 有权
    解除射频线圈

    公开(公告)号:US07973531B2

    公开(公告)日:2011-07-05

    申请号:US12302354

    申请日:2007-05-29

    IPC分类号: G01V3/00

    摘要: For detuning of radio-frequency coils (in magnetic resonance imaging and spectroscopy, for example), a conducting element (102) of a transmission cable is configured to form a primary resonant circuit tunable to at least one first resonance frequency. A second conducting element (104) of the transmission cable is configured to form a switching circuit that is electrically insulated from and reactively coupled via inductive coupling and/or capacitive coupling to the primary resonant circuit, and is adapted to tune the primary resonant circuit to at least one second resonance frequency, thereby detuning the primary resonant circuit.

    摘要翻译: 对于射频线圈的失谐(例如在磁共振成像和光谱学中),传输电缆的导电元件(102)被配置为形成可调谐至少一个第一共振频率的主谐振电路。 传输电缆的第二导电元件(104)被配置为形成开关电路,该开关电路通过电感耦合和/或电容耦合与主谐振电路电绝缘并且通过其反应耦合,并且适于将主谐振电路调谐到 至少一个第二谐振频率,从而使主谐振电路失谐。

    MR apparatus provided with an open magnet system and a quadrature coil system
    4.
    发明授权
    MR apparatus provided with an open magnet system and a quadrature coil system 失效
    MR设备具有开放磁体系统和正交线圈系统

    公开(公告)号:US06870453B2

    公开(公告)日:2005-03-22

    申请号:US10135820

    申请日:2002-04-30

    CPC分类号: G01R33/34046 G01R33/34061

    摘要: The invention relates to an MR apparatus that is provided with an open magnet system and a quadrature coil system that includes a resonator that is tuned by tuning capacitors on at least one of the two sides of the steady magnetic field, said resonator including two large-area electrical conductors that are situated at a distance from one another and are connected to one another in a number of connection points that are distributed along the circumference, and are also provided with at least two terminals that are distributed along the circumference in order to receive or generate RF magnetic fields that are mutually offset in phase. The invention also relates to a corresponding quadrature coil system.

    摘要翻译: 本发明涉及一种具有开放磁体系统和正交线圈系统的MR装置,该系统包括通过在稳定磁场的两侧中的至少一个上的调谐电容器进行调谐的谐振器,所述谐振器包括两个大电流, 区域电导体彼此间隔一定距离并且沿着圆周分布的多个连接点彼此连接,并且还设置有至少两个沿着圆周分布的端子,以便接收 或产生相位相互偏移的RF磁场。 本发明还涉及相应的正交线圈系统。

    DECOUPLING OF MULTIPLE CHANNELS OF AN MRI RF COIL ARRAY
    6.
    发明申请
    DECOUPLING OF MULTIPLE CHANNELS OF AN MRI RF COIL ARRAY 有权
    MRI射频线阵列的多通道解码

    公开(公告)号:US20130063147A1

    公开(公告)日:2013-03-14

    申请号:US13697797

    申请日:2011-04-26

    IPC分类号: G01R33/341 G01R33/54

    摘要: A radio-frequency coil assembly (18), for use in a magnetic resonance imaging system (10), includes a plurality of coil elements (18n). The coil elements (18n) are connected to a decoupling network (40) which includes a plurality of decoupling elements (40n,x) connected (via transmission lines) to pairs of coil elements (18n, 18x) at corresponding ports (64n,64x) from which the coil can be fed. The decoupling elements (40n,x) compensate for mutual coupling between pairs of corresponding coil elements. An inductive coupling loop (51n), with a constant or adjustable mutual inductance, inductively couples the associated coil element (18n) to the corresponding decoupling network port (64n). Transmission lines (52n) electrically connect each inductive coupling loop (51n) to the decoupling network (40) at the corresponding port (64x). Each transmission line (52n) has an electrical length of kλ/2 where k=0,1,2,3 . . . and λ is a wavelength of the excited and/or received resonance signals inside the transmission line.

    摘要翻译: 一种用于磁共振成像系统(10)的射频线圈组件(18)包括多个线圈元件(18n)。 线圈元件(18n)连接到去耦网络(40),该去耦网络包括多个去耦元件(40n,x),它们通过传输线连接到相应端口(64n,64x)上的线圈元件对(18n,18x) ),可以从该线圈喂入线圈。 去耦元件(40n,x)补偿相应线圈元件对之间的相互耦合。 具有恒定或可调互感的电感耦合回路(51n)将相关线圈元件(18n)感应耦合到相应的去耦网络端口(64n)。 传输线路(52n)在相应端口(64x)处将每个电感耦合回路(51n)电连接到去耦网络(40)。 每个传输线(52n)具有kλ/ 2的电长度,其中k = 0,1,2,3。 。 。 λ是传输线内的激励和/或接收的谐振信号的波长。

    Magnetic resonance imaging system and method
    7.
    发明授权
    Magnetic resonance imaging system and method 有权
    磁共振成像系统及方法

    公开(公告)号:US07701211B2

    公开(公告)日:2010-04-20

    申请号:US11721544

    申请日:2005-12-19

    IPC分类号: G01V3/00

    CPC分类号: G01R33/3607 G01R33/5611

    摘要: The present invention relates to a magnetic resonance imaging system (1) comprising a plurality of RF coils (4) forming a multi-coil array and furthermore to a magnetic resonance imaging method for such a system. In order to provide an MR imaging system and method in which a desired excitation pattern is achieved in a simple way, it is suggested to utilize an analytical procedure how to combine the single coil elements to obtain the most homogeneous B1 excitation possible with a given coil array. In other words, the homogeneity of the B1 field is improved in a very simple way. The sensitivity of each RF coil (4) of the coil array is scaled or weighted by a complex factor, i.e. phase and amplitude of each coil drive signal is adjusted accordingly. These complex factors are determined analytically utilizing the sensitivities S(8) of the coil elements (4) and the desired excitation pattern P (IO, 11). The invention allows an optimized control of the field distribution (RF shimming) for arbitrary RF coil arrays. With the invention a fast and easy independent phase and amplitude control of the coil elements (4) is provided for reducing body-induced RF non-uniformities, which appear in high field MR systems.

    摘要翻译: 本发明涉及包括形成多线圈阵列的多个RF线圈(4)以及此类系统的磁共振成像方法的磁共振成像系统(1)。 为了提供以简单的方式实现期望的激励模式的MR成像系统和方法,建议使用分析程序如何组合单个线圈元件以获得可用于给定线圈的最均匀的B1激励 数组。 换句话说,B1场的均匀性以非常简单的方式得到改善。 线圈阵列的每个RF线圈(4)的灵敏度被复合因子缩放或加权,即相应地调整每个线圈驱动信号的相位和幅度。 利用线圈元件(4)的灵敏度S(8)和期望的激励模式P(IO,11)来分析地确定这些复杂因素。 本发明允许对任意RF线圈阵列的场分布(RF匀场)的优化控制。 利用本发明,提供线圈元件(4)的快速且容易的独立相位和幅度控制,用于减少出现在高场MR系统中的体引起的RF不均匀性。

    MAGNETIC RESONANCE IMAGING SYSTEM AND METHOD
    8.
    发明申请
    MAGNETIC RESONANCE IMAGING SYSTEM AND METHOD 有权
    磁共振成像系统及方法

    公开(公告)号:US20090251144A1

    公开(公告)日:2009-10-08

    申请号:US11721544

    申请日:2005-12-19

    IPC分类号: G01R33/20 G01R33/48

    CPC分类号: G01R33/3607 G01R33/5611

    摘要: The present invention relates to a magnetic resonance imaging system (1) comprising a plurality of RF coils (4) forming a multi-coil array and furthermore to a magnetic resonance imaging method for such a system. In order to provide an MR imaging system and method in which a desired excitation pattern is achieved in a simple way, it is suggested to utilize an analytical procedure how to combine the single coil elements to obtain the most homogeneous B1 excitation possible with a given coil array. In other words, the homogeneity of the B1 field is improved in a very simple way. The sensitivity of each RF coil (4) of the coil array is scaled or weighted by a complex factor, i.e. phase and amplitude of each coil drive signal is adjusted accordingly. These complex factors are determined analytically utilizing the sensitivities S(8) of the coil elements (4) and the desired excitation pattern P (IO, 11). The invention allows an optimized control of the field distribution (RF shimming) for arbitrary RF coil arrays. With the invention a fast and easy independent phase and amplitude control of the coil elements (4) is provided for reducing body-induced RF non-uniformities, which appear in high field MR systems.

    摘要翻译: 本发明涉及包括形成多线圈阵列的多个RF线圈(4)以及此类系统的磁共振成像方法的磁共振成像系统(1)。 为了提供以简单的方式实现期望的激励模式的MR成像系统和方法,建议使用分析程序如何组合单个线圈元件以获得可用于给定线圈的最均匀的B1激励 数组。 换句话说,B1场的均匀性以非常简单的方式得到改善。 线圈阵列的每个RF线圈(4)的灵敏度被复合因子缩放或加权,即相应地调整每个线圈驱动信号的相位和幅度。 利用线圈元件(4)的灵敏度S(8)和期望的激励模式P(IO,11)来分析地确定这些复杂因素。 本发明允许对任意RF线圈阵列的场分布(RF匀场)的优化控制。 利用本发明,提供线圈元件(4)的快速且容易的独立相位和幅度控制,用于减少出现在高场MR系统中的体引起的RF不均匀性。

    MAGNETIC RESONANCE IMAGING SYSTEM WITH A MULTI-CHANNEL IMPEDANCE MATCHING NETWORK
    10.
    发明申请
    MAGNETIC RESONANCE IMAGING SYSTEM WITH A MULTI-CHANNEL IMPEDANCE MATCHING NETWORK 有权
    具有多通道阻抗匹配网络的磁共振成像系统

    公开(公告)号:US20140139218A1

    公开(公告)日:2014-05-22

    申请号:US14130379

    申请日:2012-06-21

    IPC分类号: G01R33/36

    摘要: The Magnetic Resonance Imaging (MRI) system includes a radio-frequency transmitter with multiple transmit channels. The MRI system includes an impedance matching network (320, 1402, 1502, 1602) for matching the radio-frequency transmitter to a remotely adjustable radio-frequency antenna (310, 1504, 1602) with multiple antenna elements (312, 314, 316, 318, 1404). The MRI system includes a processor (336) for controlling the MRI system. The execution of the instructions by the processor causes it to: measure (100, 200) a set of radio-frequency properties (352) of the radio-frequency antenna, calculate (102, 202) a matching network command (354) using the set of radio-frequency properties and a radio frequency model (366), and adjust (104, 204) the impedance matching network by sending the matching network command to the impedance matching network, thereby enabling automatic remote impedance matching.

    摘要翻译: 磁共振成像(MRI)系统包括具有多个发射通道的射频发射机。 MRI系统包括用于将射频发射机与具有多个天线元件(312,314,316和1602)的远程可调射频天线(310,1504,1602)匹配的阻抗匹配网络(320,1402,1502,1602) 318,1404)。 MRI系统包括用于控制MRI系统的处理器(336)。 由处理器执行指令使其:测量(100,200)一组射频天线的射频特性(352),使用该方法计算(102,202)匹配的网络命令(354) 射频特性组和射频模型(366),并通过将匹配网络命令发送到阻抗匹配网络来调整(104,204)阻抗匹配网络,从而实现自动远程阻抗匹配。