公开(公告)号：US5754047A

公开(公告)日：1998-05-19

申请号：US778251

申请日：1997-01-08

申请人： Yukari Onodera ,  Etsuji Yamamoto ,  Hiroyuki Itagaki ,  Yo Taniguchi

发明人： Yukari Onodera ,  Etsuji Yamamoto ,  Hiroyuki Itagaki ,  Yo Taniguchi

IPC分类号： G01R33/3875 ,  G01R33/54 ,  G01V3/00

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。

公开(公告)号：US5602480A

公开(公告)日：1997-02-11

申请号：US422234

申请日：1995-04-14

申请人： Yukari Onodera ,  Etsuji Yamamoto ,  Hiroyuki Itagaki ,  Yo Taniguchi

发明人： Yukari Onodera ,  Etsuji Yamamoto ,  Hiroyuki Itagaki ,  Yo Taniguchi

IPC分类号： G01R33/3875 ,  G01R33/54 ,  G01R33/20

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。

公开(公告)号：US5600245A

公开(公告)日：1997-02-04

申请号：US319724

申请日：1994-10-07

申请人： Etsuji Yamamoto ,  Hisaaki Ochi ,  Hiroyuki Itagaki ,  Yukari Onodera ,  Hiroyuki Takeuchi

发明人： Etsuji Yamamoto ,  Hisaaki Ochi ,  Hiroyuki Itagaki ,  Yukari Onodera ,  Hiroyuki Takeuchi

IPC分类号： G01R33/385 ,  G01R33/565 ,  G01V3/00

CPC分类号： G01R33/385 ,  G01R33/56518

摘要： An inspection apparatus using magnetic resonance includes magnetic field generators for generating a static magnetic field, a gradient magnetic field and a radio frequency magnetic field, respectively, a signal detector for detecting magnetic resonance signals from an inspected object, a computer for executing arithmetic operations for detection signals from the signal detector and an output device of the result of the arithmetic operations by the computer. The gradient magnetic field generator includes first and second gradient coils, the first gradient coil is a coil fixed to a magnet for generating a static magnetic field, the second gradient coil is a movable coil, and the magnetic field generated by the second gradient coil at a conducting portion of the magnet is offset by the magnetic field generated by the first gradient coil. According to this construction, an eddy current that occurs with the time change of the gradient magnetic field can be reduced.

摘要翻译： 使用磁共振的检查装置包括分别产生静磁场，梯度磁场和射频磁场的磁场发生器，用于检测来自被检查物体的磁共振信号的信号检测器，用于执行用于 来自信号检测器的检测信号和计算机的算术运算结果的输出装置。 梯度磁场发生器包括第一和第二梯度线圈，第一梯度线圈是固定到磁体上以产生静态磁场的线圈，第二梯度线圈是可动线圈，并且由第二梯度线圈产生的磁场在 磁体的导电部分由第一梯度线圈产生的磁场偏移。 根据该结构，可以减少随着梯度磁场的时间变化而发生的涡电流。

公开(公告)号：US5465719A

公开(公告)日：1995-11-14

申请号：US98775

申请日：1993-07-29

申请人： Hiroyuki Itagaki ,  Yo Taniguchi ,  Hidemi Shiono ,  Kenji Takiguchi ,  Etsuji Yamamoto

发明人： Hiroyuki Itagaki ,  Yo Taniguchi ,  Hidemi Shiono ,  Kenji Takiguchi ,  Etsuji Yamamoto

IPC分类号： A61B5/055 ,  G01R33/20 ,  G01R33/28 ,  G01R33/38 ,  G01R33/385 ,  H01F7/20

CPC分类号： G01R33/385 ,  G01R33/3802 ,  G01R33/3854

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。

公开(公告)号：US5371465A

公开(公告)日：1994-12-06

申请号：US850589

申请日：1992-03-13

申请人： Yukari Onodera ,  Etsuji Yamamoto ,  Ryuichi Suzuki

发明人： Yukari Onodera ,  Etsuji Yamamoto ,  Ryuichi Suzuki

IPC分类号： G01R33/24 ,  G01R33/3875 ,  G01R33/565 ,  G01R33/20

CPC分类号： G01R33/3875 ,  G01R33/24 ,  G01R33/56563

摘要： In an inspection apparatus using nuclear magnetic resonance (NMR), a spatial distribution of homogeneity of a static magnetic field can be quickly measured even when a heterogeneous object is inspected, by measuring simultaneously phase data and a transverse relaxation time at the same spatial position of the heterogeneous object, removing the difference of a phase term due to a chemical shift by anticipating components at that position and obtaining only the phase data resulting from static magnetic field inhomogeneity. A plurality of low-pass filters are provided to a shim power supply unit for driving a shim coil for generating additional static magnetic fields to correct static magnetic field homogeneity so that a low-pass filter having a small time constant is used at the time of adjustment of static magnetic field homogeneity so as quickly adjust static magnetic field homogeneity, and a low-pass filter having a large time constant is used at the time of the actual measurement of the object in order to prevent degradation of S/N of signals.

摘要翻译： 在使用核磁共振（NMR）的检查装置中，即使在异质物体被检查时也可以快速地测量静态磁场的均匀性的空间分布，通过同时测量相位数据和相同空间位置处的横向弛豫时间 异质物体，通过预测该位置处的分量来消除由于化学位移引起的相位项的差异，并且仅获得由静态磁场不均匀性产生的相位数据。 多个低通滤波器被提供给垫片电源单元，用于驱动垫片线圈以产生额外的静态磁场，以校正静态磁场均匀性，使得在使用具有小时间常数的低通滤波器时 调整静磁场均匀性，以便快速调整静磁场均匀性，并且在物体的实际测量时使用具有大时间常数的低通滤波器，以防止信号的S / N的劣化。

公开(公告)号：US5204626A

公开(公告)日：1993-04-20

申请号：US751972

申请日：1991-08-29

申请人： Yukari Onodera ,  Etsuji Yamamoto ,  Ryuichi Suzuki

发明人： Yukari Onodera ,  Etsuji Yamamoto ,  Ryuichi Suzuki

IPC分类号： G01N35/02 ,  G01R33/483 ,  G01R33/565

CPC分类号： G01R33/4838 ,  G01R33/56563

摘要： NMR signals of low concentration solutes are obtained with suppression of NMR signal of solvent by sequentially applying a first RF pulse sequence, a 180.degree. RF pulse and a second RF pulse sequence to an object. Each of the first and second RF pulse sequence includes equally spaced RF pulses which have flip angles in accordance with binominal coefficients. Phase errors due to inhomogeneity of a static magnetic field are cancelled through the two-time application of equally spaced RF pulse sequence.

摘要翻译： 通过依次对物体施加第一RF脉冲序列，180°RF脉冲和第二RF脉冲序列，抑制溶剂的NMR信号，获得低浓度溶质的NMR信号。 第一和第二RF脉冲序列中的每一个包括等间隔的RF脉冲，其具有根据二项式系数的翻转角。 通过两次施加等间隔的RF脉冲序列来消除由静态磁场的不均匀性引起的相位误差。

公开(公告)号：US5684398A

公开(公告)日：1997-11-04

申请号：US297565

申请日：1994-09-01

申请人： Kenji Takiguchi ,  Yo Taniguchi ,  Etsuji Yamamoto ,  Shigeru Watanabe ,  Katsunori Suzuki ,  Ryuzaburo Takeda ,  Shoji Kondo

发明人： Kenji Takiguchi ,  Yo Taniguchi ,  Etsuji Yamamoto ,  Shigeru Watanabe ,  Katsunori Suzuki ,  Ryuzaburo Takeda ,  Shoji Kondo

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。

公开(公告)号：US5789922A

公开(公告)日：1998-08-04

申请号：US645478

申请日：1996-05-13

申请人： Hisaaki Ochi ,  Etsuji Yamamoto ,  Yo Taniguchi

发明人： Hisaaki Ochi ,  Etsuji Yamamoto ,  Yo Taniguchi

IPC分类号： G01R33/46 ,  A61B5/055 ,  G01R33/48 ,  G01R33/561

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。

公开(公告)号：US5808467A

公开(公告)日：1998-09-15

申请号：US653315

申请日：1996-05-24

申请人： Hisaaki Ochi ,  Yo Taniguchi ,  Kenichi Okajima ,  Yoshitaka Bito ,  Etsuji Yamamoto

发明人： Hisaaki Ochi ,  Yo Taniguchi ,  Kenichi Okajima ,  Yoshitaka Bito ,  Etsuji Yamamoto

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。

公开(公告)号：US5382902A

公开(公告)日：1995-01-17

申请号：US985645

申请日：1992-12-07

申请人： Yo Taniguchi ,  Etsuji Yamamoto

发明人： Yo Taniguchi ,  Etsuji Yamamoto

IPC分类号： A61B5/055 ,  G01R33/32 ,  G01R33/563 ,  G01R33/567 ,  G01V3/00

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。