Nuclear magentic resonance imaging apparatus
    1.
    发明授权
    Nuclear magentic resonance imaging apparatus 失效
    核磁共振成像装置

    公开(公告)号:US5465719A

    公开(公告)日:1995-11-14

    申请号:US98775

    申请日:1993-07-29

    摘要: A bobbin for holding a gradient magnetic field coil, having a changeable size and sectional shape (a separable bobbin) is constituted by assembling coil supporters (a bobbin divided into a plurality of segments). The separable bobbin has coil supporters of an upper part a bottom part and a set of side surface parts and at least two supporting rods made of a nonmagnetic substance are fitted to the side surface parts of the coil supporters. Holes permitting the insertion of the supporting rods are bored in the upper and bottom parts of the coil supporters. The length d1 between both side surface parts can be made variable by adjusting the insertion length of the supporting rod into the upper and bottom parts. Accordingly, the distance between a patient and a gradient magnetic field can be reduced, and an intended gradient magnetic field intensity can be generated by a smaller current producing the gradient magnetic field than in the prior art. Setting of the patient to an MRI imaging apparatus becomes also easier, and there can be obtained a gradient magnetic field coil capable of being easily fitted and removed to and from the MRI imaging apparatus.

    摘要翻译: 用于保持具有可变尺寸和截面形状(分离线圈架)的梯度磁场线圈的线轴由线圈支架(分为多个段的线轴)组装而成。 可分离筒管具有上部的线圈支撑件,底部部分和一组侧面部分,并且至少两个由非磁性物质制成的支撑杆装配到线圈支撑件的侧表面部分。 允许插入支撑杆的孔在线圈支撑件的上部和底部中钻孔。 通过将支撑杆的插入长度调节到上部和底部,两个侧面部分之间的长度d1可以变化。 因此,可以减少患者与梯度磁场之间的距离,并且通过产生梯度磁场的较小电流可以产生预期的梯度磁场强度,而不是现有技术。 将患者设置到MRI成像设备变得更容易,并且可以获得能够容易地装配和去除MRI成像设备的梯度磁场线圈。

    Inspection method and apparatus using nuclear magnetic resonance
    2.
    发明授权
    Inspection method and apparatus using nuclear magnetic resonance 失效
    使用核磁共振的检查方法和装置

    公开(公告)号:US5754047A

    公开(公告)日:1998-05-19

    申请号:US778251

    申请日:1997-01-08

    CPC分类号: G01R33/3875 G01R33/4835

    摘要: An inspection method by means of an inspection apparatus using nuclear magnetic resonance and having magnetic field generating apparatus for generating a static magnetic field, gradient magnetic fields and an RF magnetic field; magnetic field generating apparatus by means of additional shim coils, which vary homogeneity of the static magnetic field by varying current flowing therethrough; signal detecting apparatus for detecting nuclear magnetic resonance signals from an object to be inspected; an apparatus for processing signals detected by the signal detecting apparatus; and control apparatus for controlling currents flowing through the shim coils, which method using nuclear magnetic resonance comprises a step of storing shim currents corresponding to each of a plurality of slices, capable of improving homogeneity of the static magnetic field for each of the plurality of slices, and a step of switching over the shim currents to those corresponding to a relevant slice to be measured prior to measurements of nuclear magnetic resonance signals from the slice. This inspection method can be applied also to a case where measurements of other slices are effected in intervals of measurements of the relevant slice.

    摘要翻译: 使用核磁共振的检查装置的检查方法,具有用于产生静磁场的磁场产生装置,梯度磁场和RF磁场; 通过附加的垫片线圈产生磁场产生装置,其通过改变流过其中的电流来改变静态磁场的均匀性; 信号检测装置,用于检测来自被检体的核磁共振信号; 用于处理由信号检测装置检测的信号的装置; 以及用于控制流过所述垫片线圈的电流的控制装置,所述使用核磁共振的方法包括存储对应于多个片中的每一个的片状电流的步骤,能够提高所述多个片中的每一个的静态磁场的均匀性 以及在来自切片的核磁共振信号的测量之前,将垫片电流切换到与要测量的相关切片相对应的片电流的步骤。 这种检查方法也可以应用于其他切片的测量在相关切片的测量间隔中实现的情况。

    Fluid measurement method using nuclear magnetic resonance imaging and
apparatus therefor
    3.
    发明授权
    Fluid measurement method using nuclear magnetic resonance imaging and apparatus therefor 失效
    使用核磁共振成像的流体测量方法及其设备

    公开(公告)号:US5684398A

    公开(公告)日:1997-11-04

    申请号:US297565

    申请日:1994-09-01

    IPC分类号: G01R33/563 A61B5/0265

    CPC分类号: G01R33/56308

    摘要: A bolus of magnetized blood is formed by at least two radio frequency magnetic fields, and readout gradient magnetic fields are repeatedly applied at a proportion of 1:-2:1 along a blood vessel so as to continuously obtain a first echo signal whose phase change due to velocity is corrected, from the moving bolus. This first echo signal provides velocity information on the blood stream. The sequence of the readout gradient magnetic fields is repeatedly applied at a proportion of (.sqroot.2-1):-2:2:-(.sqroot.2-1) so as to continuously obtain a second echo signal whose phase change due to velocity and acceleration is corrected, from the moving bolus. Acceleration information of the blood stream is extracted by calculating the difference between the first echo signal and the second echo signal. The velocity information and/or the acceleration information is displayed in superposition with a specific blood vessel of an angiogram shot in advance.

    摘要翻译: 通过至少两个射频磁场形成大量的磁化血液,沿着血管以1:-2:1的比例反复施加读出梯度磁场,以便连续获得相位变化的第一回波信号 由于速度被校正,从移动推注。 该第一回波信号提供关于血流的速度信息。 读出梯度磁场的顺序以(2ROOT + E,rad 2 + EE -1): - 2:2: - (2ROOT + E,rad 2 + EE -1)的比例重复施加,以连续 从移动推注获得由于速度和加速度而导致的相位变化的第二回波信号。 通过计算第一回波信号和第二回波信号之间的差来提取血流的加速度信息。 速度信息和/或加速度信息与预先拍摄的血管造影的特定血管重叠地显示。

    Inspection method and apparatus using nuclear magnetic resonance
    4.
    发明授权
    Inspection method and apparatus using nuclear magnetic resonance 失效
    使用核磁共振的检查方法和装置

    公开(公告)号:US5602480A

    公开(公告)日:1997-02-11

    申请号:US422234

    申请日:1995-04-14

    CPC分类号: G01R33/3875 G01R33/4835

    摘要: An inspection method by means of an inspection apparatus using nuclear magnetic resonance and having magnetic field generating apparatus for generating a static magnetic field, gradient magnetic fields and an RF magnetic field; magnetic field generating apparatus by means of additional shim coils, which vary homogeneity of the static magnetic field by varying current flowing therethrough; signal detecting apparatus for detecting nuclear magnetic resonance signals from an object to be inspected; an apparatus for processing signals detected by the signal detecting apparatus; and control apparatus for controlling currents flowing through the shim coils, which method using nuclear magnetic resonance comprises a step of storing shim currents corresponding to each of a plurality of slices, capable of improving homogeneity of the static magnetic field for each of the plurality of slices, and a step of switching over the shim currents to those corresponding to a relevant slice to be measured prior to measurements of nuclear magnetic resonance signals from the slice. This inspection method can be applied also to a case where measurements of other slices are effected in intervals of measurements of the relevant slice.

    摘要翻译: 使用核磁共振的检查装置的检查方法,具有用于产生静磁场的磁场产生装置,梯度磁场和RF磁场; 通过附加的垫片线圈产生磁场产生装置,其通过改变流过其中的电流来改变静态磁场的均匀性; 信号检测装置,用于检测来自被检体的核磁共振信号; 用于处理由信号检测装置检测的信号的装置; 以及用于控制流过所述垫片线圈的电流的控制装置,所述使用核磁共振的方法包括存储对应于多个片中的每一个的片状电流的步骤,能够提高所述多个片中的每一个的静态磁场的均匀性 以及在来自切片的核磁共振信号的测量之前,将垫片电流切换到与要测量的相关切片相对应的片电流的步骤。 该检查方法也可以应用于在相关切片的测量的间隔中实现其他切片的测量的情况。

    RF probe and inspection system using NMR using the same
    5.
    发明授权
    RF probe and inspection system using NMR using the same 失效
    射频探头和使用核磁共振的检查系统

    公开(公告)号:US5808467A

    公开(公告)日:1998-09-15

    申请号:US653315

    申请日:1996-05-24

    IPC分类号: G01R33/3415 G01V3/00

    CPC分类号: G01R33/3415

    摘要: In the inspection system using nuclear magnetic resonance comprising magnetic field generators such as a static magnetic field, a gradient magnetic field, and an RF magnetic field, an RF probe for detecting an NMR signal from a subject, and a calculator for operating a detected signal by the RF probe, a RF probe for detection comprises a plurality of coils arranged in the predetermined direction and includes a plurality of switching elements and the inspection system selects two or more coils from the plurality of coils for each measurement of NMR signals, turns the switching elements connected to the selected coils ON, turns the switching elements connected to coils other than the selected coils OFF, changes a combination of two or more coils for each measurement of NMR signals, and changes the sensitivity distribution of the RF probe in the predetermined direction according to the Wavelet basis function for each measurement of NMR signals.

    摘要翻译: 在使用包括诸如静磁场,梯度磁场和RF磁场的磁场发生器的核磁共振的检查系统中,用于检测来自被检体的NMR信号的RF探针和用于操作检测信号的计算器 通过RF探头,用于检测的RF探针包括沿预定方向布置的多个线圈,并且包括多个开关元件,并且检查系统从每个测量NMR信号中选择来自多个线圈的两个或更多个线圈, 连接到所选择的线圈的开关元件接通,将与所选线圈以外的线圈相连的开关元件断开,对每个NMR信号的测量改变两个或更多个线圈的组合,并将RF探针的灵敏度分布改变为预定的 根据每个NMR信号测量的小波基函数的方向。

    Method for eliminating motional artifacts in magnetic resonance imaging
    6.
    发明授权
    Method for eliminating motional artifacts in magnetic resonance imaging 失效
    消除磁共振成像中运动伪影的方法

    公开(公告)号:US5382902A

    公开(公告)日:1995-01-17

    申请号:US985645

    申请日:1992-12-07

    CPC分类号: G01R33/5676

    摘要: A magnetic resonance imaging method for obtaining an image of an object laid in a space in which a static magnetic field is applied, so as to substantially eliminate motional artifacts. The method includes sequentially measuring a plurality of magnetic resonance views with a plurality of encodings by repeating a measurement sequence of exciting nuclear spins in said object, applying a phase-encoding field gradient along a first direction with programmed time integral to encode the excited spins, and detecting the encoded spins in the presence of a readout field gradient along a second direction to generate a magnetic resonance view so that measurements of magnetic resonance views with at least low-order encoding are obtained during the repetition of the measurement sequence. Thereafter respective magnetic resonance views are subjected to a first Fourier transformation so as to generate a plurality of projection views with a plurality of encodings forming a data matrix in a hybrid domain, displacements in respective projection views due to motion of the object are corrected using displacement information obtained from projection views with low-order encodings so as to generate a corrected data matrix in the hybrid domain, and the corrected data matrix is subjected to a second Fourier transformation so as to generate the image of the object.

    摘要翻译: 一种磁共振成像方法,用于获得放置在施加静磁场的空间中的物体的图像,以便基本上消除运动伪像。 该方法包括通过重复所述物体中激发的核自旋的测量序列来顺序地测量具有多个编码的多个磁共振视图,沿着第一方向施加相位编码场梯度以编程的时间积分来编码激励的自旋, 以及在沿着第二方向存在读出场梯度的情况下检测编码的旋转以产生磁共振视图,使得在重复测量序列期间获得具有至少低阶编码的磁共振视图的测量。 然后对各磁共振视图进行第一傅里叶变换,以便在混合域中产生多个形成数据矩阵的编码的多个投影视图,由于对象的运动而在各个投影视图中的位移使用位移进行校正 从具有低阶编码的投影视图获得的信息,以便在混合域中产生校正数据矩阵,并且对经校正的数据矩阵进行第二傅立叶变换,以便生成对象的图像。

    Inspecting method and apparatus based on nuclear magnetic resonance
using burst wave as exciting high frequency pulse
    7.
    发明授权
    Inspecting method and apparatus based on nuclear magnetic resonance using burst wave as exciting high frequency pulse 失效
    基于核磁共振的检测方法和装置,使用突发波作为激发高频脉冲

    公开(公告)号:US5789922A

    公开(公告)日:1998-08-04

    申请号:US645478

    申请日:1996-05-13

    CPC分类号: G01R33/446 G01R33/5615

    摘要: In an inspecting method based on nuclear magnetic resonance, a burst wave having a plurality of sub-pulses frequency-modulated with a high frequency is generated, the burst wave is amplitude-modulated with at least a function which repeats polarity inversion, the amplitude-modulated burst wave is irradiated, as an exciting high frequency pulse, to an object to be inspected, and gradient magnetic fields are generated in predetermined pulse sequence to measure a nuclear magnetic resonance signal.

    摘要翻译: 在基于核磁共振的检查方法中,产生具有高频率频率调制的多个子脉冲的脉冲波,突发波被至少以重复极性反转的功能进行幅度调制, 作为激励高频脉冲将调制脉冲波照射到要检查的物体,并且以预定脉冲序列产生梯度磁场以测量核磁共振信号。

    Nuclear magnetic resonance imaging apparatus
    8.
    发明授权
    Nuclear magnetic resonance imaging apparatus 有权
    核磁共振成像装置

    公开(公告)号:US08614574B2

    公开(公告)日:2013-12-24

    申请号:US12993905

    申请日:2009-05-22

    IPC分类号: G01V3/00 A61B5/05 G01R33/48

    摘要: A magnetic resonance imaging apparatus is provided, which is capable of reducing SAR while maintaining S/N ratio and image contrast in a GrE-type pulse sequence, regardless of whether a synchronous imaging is performed or not.The present invention controls a flip angle as to each measurement set 409 that is obtained by division according to the size of phase encoding and a body motion cycle of a subject in the GrE-type pulse sequence. In a set 501 which measures echoes with phase encoding having a minimum absolute value, the flip angle is maximized as to the RF pulse having a minimum phase encoding amount and at least one RF pulse irradiated immediately before. As for the other RF pulses, the flip angle varies within a range less than the maximum, irrespective of the non-imaging mode, the imaging mode, or the size of phase encoding.

    摘要翻译: 提供一种磁共振成像装置,其能够在保持GrE型脉冲序列中的S / N比和图像对比度的同时减小SAR,而不管是否执行同步成像。 本发明通过根据GrE型脉冲序列中的对象的相位编码的大小和体动周期进行分割而获得的每个测量组409来控制翻转角。 在测量具有最小绝对值的相位编码回波的组501中,对于具有最小相位编码量的RF脉冲和紧接着照射的至少一个RF脉冲,翻转角度最大化。 对于其他RF脉冲,翻转角度在小于最大值的范围内变化,而与非成像模式,成像模式或相位编码的大小无关。

    System of generating a magnetic field and MRI system using the system of generating a magnetic field
    9.
    发明授权
    System of generating a magnetic field and MRI system using the system of generating a magnetic field 失效
    使用产生磁场的系统产生磁场和MRI系统的系统

    公开(公告)号:US07358726B2

    公开(公告)日:2008-04-15

    申请号:US10242442

    申请日:2002-09-13

    IPC分类号: G01V3/00

    CPC分类号: G01R33/3806 A61B5/055

    摘要: An MRI system using an open type magnet, wherein two coils different in radius for generating gradient magnetic fields in a vertical direction are arranged in the open type magnet for generating a static magnetic field in the vertical direction. Currents are caused to flow through the two coils in directions opposite to each other to improve the degree of uniformity of the magnetic field in the vertical direction, thereby reducing the degradation thereof by equal to or smaller than 2 figures compared with the degree of uniformity of the static magnetic field generated by the existing MRI system. The positional information about a read-out direction is given through the dynamic control for the RF magnetic field to give the positional information about other two axes directions based on the gradient magnetic field having strength much larger than that of nonuniformity of the magnetic field.

    摘要翻译: 使用开放型磁体的MRI系统,其中在垂直方向上产生梯度磁场的半径不同的两个线圈被布置在用于在垂直方向上产生静态磁场的开放型磁体中。 引起电流流过彼此相反方向的两个线圈,以提高垂直方向上磁场的均匀度,从而与其均匀度相比降低等于或小于2个数字 由现有MRI系统产生的静磁场。 通过对RF磁场的动态控制,给出关于读出方向的位置信息,基于具有比磁场不均匀性强的强度的梯度磁场给出关于其他两个轴方向的位置信息。

    NUCLEAR MAGNETIC RESONANCE IMAGING APPARATUS
    10.
    发明申请
    NUCLEAR MAGNETIC RESONANCE IMAGING APPARATUS 有权
    核磁共振成像装置

    公开(公告)号:US20110133735A1

    公开(公告)日:2011-06-09

    申请号:US12993905

    申请日:2009-05-22

    IPC分类号: G01R33/44

    摘要: A magnetic resonance imaging apparatus is provided, which is capable of reducing SAR while maintaining S/N ratio and image contrast in a GrE-type pulse sequence, regardless of whether a synchronous imaging is performed or not.The present invention controls a flip angle as to each measurement set 409 that is obtained by division according to the size of phase encoding and a body motion cycle of a subject in the GrE-type pulse sequence. In a set 501 which measures echoes with phase encoding having a minimum absolute value, the flip angle is maximized as to the RF pulse having a minimum phase encoding amount and at least one RF pulse irradiated immediately before. As for the other RF pulses, the flip angle varies within a range less than the maximum, irrespective of the non-imaging mode, the imaging mode, or the size of phase encoding.

    摘要翻译: 提供一种磁共振成像装置,其能够在保持GrE型脉冲序列中的S / N比和图像对比度的同时减小SAR,而不管是否执行同步成像。 本发明通过根据GrE型脉冲序列中的对象的相位编码的大小和体动周期进行分割而获得的每个测量组409来控制翻转角。 在测量具有最小绝对值的相位编码回波的组501中,对于具有最小相位编码量的RF脉冲和紧接着照射的至少一个RF脉冲,翻转角度最大化。 对于其他RF脉冲,翻转角度在小于最大值的范围内变化,而与非成像模式,成像模式或相位编码的大小无关。