公开(公告)号：US20190004130A1

公开(公告)日：2019-01-03

申请号：US16122661

申请日：2018-09-05

申请人： Hyperfine Research, Inc.

发明人： Michael Stephen Poole ,  Cedric Hugon ,  Hadrien A. Dyvorne ,  Laura Sacolick ,  William J. Mileski ,  Jeremy Christopher Jordan ,  Alan B. Katze, JR. ,  Jonathan M. Rothberg ,  Todd Rearick ,  Christopher Thomas McNulty

IPC分类号： G01R33/385 ,  G01R33/383 ,  G01R33/389 ,  A61B50/13 ,  A61B90/00

摘要： According to some aspects, a portable magnetic resonance imaging system is provided, comprising a B0 magnet configured to produce a B0 magnetic field for an imaging region of the magnetic resonance imaging system, a noise reduction system configured to detect and suppress at least some electromagnetic noise in an operating environment of the portable magnetic resonance imaging system, and electromagnetic shielding provided to attenuate at least some of the electromagnetic noise in the operating environment of the portable magnetic resonance imaging system, the electromagnetic shielding arranged to shield a fraction of the imaging region of the portable magnetic resonance imaging system. According to some aspects, the electromagnetic shield comprises at least one electromagnetic shield structure adjustably coupled to the housing to provide electromagnetic shielding for the imaging region in an amount that can be varied.

公开(公告)号：US20170069415A1

公开(公告)日：2017-03-09

申请号：US15122754

申请日：2014-11-12

申请人： FORSCHUNGSZENTRUM JUELICH GMBH

发明人： Mikhail FALEY ,  Ulrich POPPE

IPC分类号： H01F7/20 ,  H01J29/56 ,  H01J37/141 ,  H01F6/06 ,  G01R33/389

CPC分类号： H01F7/20 ,  G01R33/389 ,  H01F6/00 ,  H01F6/06 ,  H01F7/0278 ,  H01F7/202 ,  H01J29/56 ,  H01J37/141 ,  H01J37/1416 ,  H01J2237/26

摘要： A device for applying a constant magnetic field to a volume of interest (VOI) has been developed. At least one magnetic field source and a permeable yoke, which guides the magnetic flux generated by this magnetic field source into the volume of interest (VOI). The yoke is guided through at least one closed conductor loop, which can be switched to the superconducting state so that, in the superconducting state of the conductor loop, a change in the flux through the yoke effects a current counteracting this change along the conductor loop. It has been identified that, in this way, the stabilizer for the magnetic field can be spaced so far apart from the volume of interest (VOI) that the field distribution in this volume is virtually no longer influenced. At the same time, the quality of the stabilization is also improved, since the conductor loop is no longer exposed to the entire magnetic field prevailing in the volume of interest (VOI). The entire critical current that the conductor loop can carry is available as a control range for compensating for fluctuations in the flux. In comparison with the prior art, the invention first accepts the apparent disadvantage that, in general, additional means are required for switching the conductor loop back and forth between the superconducting state and the normal-conducting state. However, this disadvantage is more than compensated for.

摘要翻译： 已经开发了用于将恒定磁场施加到感兴趣体积（VOI）的装置。 至少一个磁场源和可渗透轭，其将由该磁场源产生的磁通量引导到感兴趣体积（VOI）中。 磁轭被引导通过至少一个封闭的导体环路，该环路可以切换到超导状态，使得在导体环路的超导状态下，通过磁轭的磁通量的变化会产生电流抵消沿导体环路的这种变化 。 已经确定，以这种方式，用于磁场的稳定器可以与感兴趣的体积（VOI）隔开距离，使得该体积中的场分布实际上不再受到影响。 同时，由于导体环不再暴露于感兴趣体积（VOI）中的整个磁场，稳定性的质量也得到改善。 导体回路可承载的整个临界电流可用作补偿通量波动的控制范围。 与现有技术相比，本发明首先接受一个明显的缺点，一般来说，在超导状态和正常导通状态之间来回切换导体环路需要附加装置。 然而，这个缺点是被补偿的。

公开(公告)号：US08723523B2

公开(公告)日：2014-05-13

申请号：US12988406

申请日：2009-04-17

申请人： Munetaka Tsuda

发明人： Munetaka Tsuda

IPC分类号： G01R33/3815 ,  G01R33/389 ,  G01R33/3873 ,  G01R33/421

CPC分类号： G01R33/389 ,  G01R33/3806 ,  G01R33/3815 ,  G01R33/3873 ,  G01R33/3875

摘要： A magnetic resonance imaging apparatus includes: a pair of static magnetic field generators separately disposed at the top and bottom of an imaging space in which a subject is placed; a shim magnetic material, disposed on the imaging-space side of each of the pair of static magnetic field generators, for generating a magnetic field to adjust the static magnetic field; a gradient magnetic field generator; a high-frequency magnetic field generator; a temperature sensor for directly or indirectly measuring the temperature of the shim magnetic material; and a controller for controlling the gradient magnetic field generator and the high-frequency magnetic field generator to execute an imaging pulse sequence. The controller determines the inhomogeneity of the static magnetic field from the output of the temperature sensor, considering the change in a magnetic field adjustment parameter due to the temperature change of the shim magnetic material, and causes a warning message to be presented if the determined static magnetic field inhomogeneity has exceeded a predetermined allowable value.

摘要翻译： 一种磁共振成像装置包括：一对静态磁场发生器，分别设置在放置被摄体的成像空间的顶部和底部; 设置在所述一对静磁场发生器中的每一个的成像空间侧上的垫片磁性材料，用于产生磁场以调整静磁场; 梯度磁场发生器; 高频磁场发生器; 用于直接或间接测量垫片磁性材料的温度的温度传感器; 以及用于控制倾斜磁场发生器和高频磁场发生器以执行成像脉冲序列的控制器。 考虑到由于垫片磁性材料的温度变化引起的磁场调整参数的变化，控制器从温度传感器的输出确定静态磁场的不均匀性，并且如果确定的静态 磁场不均匀性已经超过预定的允许值。

公开(公告)号：US20050068028A1

公开(公告)日：2005-03-31

申请号：US10498720

申请日：2002-12-18

申请人： Adrianus Machielsen

发明人： Adrianus Machielsen

IPC分类号： G01R33/389 ,  A61B5/055 ,  G01R33/385 ,  G01R33/565

CPC分类号： G01R33/385 ,  G01R33/56518

摘要： Gradient pulses are generated by current conducting gradient coils. High-frequency components cause the center of gravity of the current to be shifted by mutual influencing of the coil conductors. The shift depends on the electrical resistance of the conductor material, which in turn depends on the temperature of said conductor material, and on the frequency (, such that the magnetic gradient field B decreases with increasing frequency. This phenomenon manifests itself as a delay (of the gradient pulse with respect to the gradient demand D. The invention proposes to determine during the pulse a quantity representing the conducting state of the conductors of the gradient system and to use a model of the MRI apparatus to calculate the gradient delay (from that quantity and to correct the gradient demand for said delay.

摘要翻译： 梯度脉冲由电流传导梯度线圈产生。 高频分量导致电流的重心通过线圈导体的相互影响而移动。 该移动取决于导体材料的电阻，其又取决于所述导体材料的温度和频率（使得磁梯度场B随着频率的增加而减小，这种现象本身表现为延迟（ 相对于梯度要求D的梯度脉冲。本发明提出在脉冲期间确定表示梯度系统的导体的导电状态的量，并使用MRI装置的模型来计算梯度延迟（从该 数量并纠正所述延迟的梯度要求。

公开(公告)号：US06844732B2

公开(公告)日：2005-01-18

申请号：US10409061

申请日：2003-04-09

申请人： Davide Carlini ,  Alessandro Carrozzi ,  Aldo Ginanneschi ,  Paolo Iaia

发明人： Davide Carlini ,  Alessandro Carrozzi ,  Aldo Ginanneschi ,  Paolo Iaia

IPC分类号： G01R33/389 ,  G01R33/565 ,  G01V3/00

CPC分类号： G01R33/389 ,  G01R33/56563

摘要： A method for compensating for magnetic noise fields in spatial volumes includes determining the strength of a magnetic field outside said spatial volume; defining the correlation between the noise field outside the spatial volume and the corresponding noise field inside said spatial volume; generating a magnetic compensation field for neutralizing the noise field in said spatial volume. The method further provides separate detection of noise fields with frequencies in the range of at least two different frequency bands.

摘要翻译： 用于补偿空间体积中的磁噪声场的方法包括确定所述空间体积之外的磁场的强度; 定义空间体积之外的噪声场与所述空间体积内的相应噪声场之间的相关性; 产生用于中和所述空间体积中的噪声场的磁补偿场。 该方法进一步提供具有至少两个不同频带范围内的频率的噪声场的单独检测。

公开(公告)号：US5912558A

公开(公告)日：1999-06-15

申请号：US970261

申请日：1997-11-14

申请人： James A. Halamek ,  Mark J. Loncar ,  Heidi A. Schlitt

发明人： James A. Halamek ,  Mark J. Loncar ,  Heidi A. Schlitt

IPC分类号： G01R33/389 ,  A61B5/055 ,  G01R33/36 ,  G01V3/00

CPC分类号： G01R33/583

摘要： A method (100) of automatically tuning a radio frequency transmitter (24) and receiver (38) in a magnetic resonance imaging apparatus to an optimum frequency includes generating and acquiring (104) a magnetic resonance signal. The magnetic resonance signal is transformed to the frequency domain and spectral magnitude of the signal is computed (106). A center of gravity interpolation is performed (110) on the spectral magnitude to obtain a desired frequency sampling. A model function is generated based upon a strength of a main magnetic field which has peaks separated by the same separation as that for fat and water signals. The spectral magnitude is correlated (112) with the model function and a peak having the greatest magnitude is located therefrom. The location of a species peak along the spectral magnitude is estimated (114) from empirically derived information, the strength of the main magnetic field and the location of the correlation peak. A region of the spectral magnitude to be examined is defined (116) from empirically derived information, and a peak within this region is located (118) which is nearest the estimated location. Ultimately, the frequency of the radio frequency transmitter and receiver is set (122) to align with the peak located within the region that is nearest the estimated location.

摘要翻译： 将磁共振成像设备中的射频发射器（24）和接收器（38）自动调谐到最佳频率的方法（100）包括产生和获取（104）磁共振信号。 将磁共振信号变换为频域，并计算信号的频谱幅度（106）。 对频谱幅度执行重心插值（110）以获得期望的频率采样。 基于主磁场的强度产生模型函数，该主磁场具有通过与脂肪和水信号相同的分离分离的峰值。 光谱幅度与模型函数相关（112），并且具有最大幅度的峰位于其中。 根据经验导出的信息，主磁场的强度和相关峰的位置估计（114）沿着光谱幅度的物种峰的位置。 根据经验导出的信息定义要检查的光谱幅度的区域（116），并且该区域内的峰位于离估计位置最近的位置（118）。 最终，射频发射机和接收机的频率被设置为（122）以与位于距估计位置最近的区域内的峰对齐。

公开(公告)号：US5905377A

公开(公告)日：1999-05-18

申请号：US690528

申请日：1996-07-31

申请人： Adam B. Kerr ,  John M. Pauly

发明人： Adam B. Kerr ,  John M. Pauly

IPC分类号： G01R33/389 ,  G01R33/565 ,  G01V3/00

CPC分类号： G01R33/389 ,  G01R33/56518 ,  G01R33/56563

摘要： Time-varying error between a prescribed magnetic field and an actual magnetic field is identified from a self-encoding technique and the measurement of detected responses to various magnetic read-out gradients. The gradients can be a sinusoidal, step function, or other suitable form which enables the actual responses to be obtained from which transfer functions can be defined. In one embodiment, the data can effectively frequency sample the transfer function of the system. A gradient-recalled echo occurs each time the self-encode lobe is refocussed, and the phase of the echo peak is used to estimate the time variation of the main magnetic field, B.sub.0 (t).

摘要翻译： 从自编码技术和对各种磁读出梯度的检测到的响应的测量来识别规定磁场和实际磁场之间的时变误差。 梯度可以是正弦，阶梯函数或其他合适的形式，其使得能够从可以定义传递函数获得实际响应。 在一个实施例中，数据可以有效地对系统的传递函数进行频率采样。 每次自编码波瓣重新聚焦时都会发生梯度回波，回波峰值的相位用于估计主磁场B0（t）的时间变化。

公开(公告)号：US5631561A

公开(公告)日：1997-05-20

申请号：US451564

申请日：1995-05-26

申请人： Eckart Stetter

发明人： Eckart Stetter

IPC分类号： G01R33/389 ,  G05F7/00 ,  G01R33/28

CPC分类号： G05F7/00 ,  G01R33/389

摘要： For measuring the basic field, at least one magnetic field probe is attached in the examination region of the nuclear magnetic resonance tomography system. The influence of the magnetic field gradients on the measurement is eliminated by a correction stage for pulsed magnetic field gradients arising from the switched gradients.

摘要翻译： 为了测量基本场，在核磁共振断层摄影系统的检查区域中至少安装一个磁场探头。 磁场梯度对测量的影响由切换梯度产生的脉冲磁场梯度的校正阶段消除。

公开(公告)号：US5519319A

公开(公告)日：1996-05-21

申请号：US491632

申请日：1995-06-19

申请人： Thomas B. Smith ,  Scott A. Marino ,  Ronald J. Tache ,  David R. Day ,  Christian I. Tanzer ,  Tadd B. Hughes ,  Ajoy K. Roy

发明人： Thomas B. Smith ,  Scott A. Marino ,  Ronald J. Tache ,  David R. Day ,  Christian I. Tanzer ,  Tadd B. Hughes ,  Ajoy K. Roy

IPC分类号： G01R33/389 ,  G01R33/44 ,  G01R33/46 ,  G01V3/00

CPC分类号： G01R33/389 ,  G01N24/085 ,  G01N24/082 ,  G01R33/4625

摘要： A nuclear magnetic resonance (NMR) system, and related method, develops two or more regression equations or models for a particular polymer property of interest (e.g., melt index or MI) during a calibration procedure using known samples of a material. The polymer material can be, for example, a plastic (e.g., polyethylene, polypropylene, or polystyrene) or a rubber (e.g., ethylene propylene rubber). Regression models for one or more discrete (i.e., two-valued) variables also are developed during calibration, and these models allow a prediction to be made about which of the two or more property (e.g., MI) models should be used for any particular sample of unknown material. The prediction obtained from the discrete variable model indicates which of the two or more models will produce the most accurate estimation of the property of interest for the unknown sample. The best model is thus selected, and then it is used to estimate the property of interest.

摘要翻译： 核磁共振（NMR）系统和相关方法在使用已知材料样品的校准过程期间针对特定的感兴趣的聚合物性质（例如熔体指数或MI）开发两个或多个回归方程或模型。 聚合物材料可以是例如塑料（例如聚乙烯，聚丙烯或聚苯乙烯）或橡胶（例如乙丙橡胶）。 在校准期间，还开发了一个或多个离散（即二值）变量的回归模型，这些模型允许对两个或多个属性（例如，MI）模型中的哪一个应用于任何特定的模型进行预测 未知材料样品。 从离散变量模型获得的预测表明两个或更多个模型中的哪一个将产生未知样本的关注属性的最准确估计。 因此选择最佳模型，然后用于估计感兴趣的属性。

公开(公告)号：US5296810A

公开(公告)日：1994-03-22

申请号：US942521

申请日：1992-09-09

申请人： Michael A. Morich

发明人： Michael A. Morich

IPC分类号： A61B5/055 ,  G01R33/385 ,  G01R33/389 ,  G01R33/421 ,  G01R33/422 ,  G01R33/20

CPC分类号： G01R33/385 ,  G01R33/422 ,  H01F6/06 ,  G01R33/3856 ,  G01R33/4215

摘要： A superconducting magnetic imaging apparatus includes a vacuum vessel (40) having a central helium reservoir (48) in which superconducting magnetic coil windings (44) are maintained at a superconducting temperature. The vacuum vessel defines an internal bore (42) within which a self-shielded gradient coil assembly (14) and an RF coil (22) are received. The self-shielded coil assembly includes an inner former (60) which defines an imaging region (12) within which an imaged portion of the patient are received. X and y-gradient coils having winding patterns (62) are bonded to the former (60) forming an integral structure. A z-gradient coil (70) is mounted to mechanical reinforcement structure (72) to be held in a spaced relationship from the x and y-gradient coils with an air gap (74) in between. This facilitates the dissipation of heat generated by the large current pulses applied to the x and y-gradient coils. An outer former (80) of larger diameter than the z-gradient coils is received in the bore and supports the inner former therein. X, y, and z-gradient secondary or shielding coils (82, 84) are bonded to the outer former for preventing the gradients generated by the primary gradient coils from inducing gradient eddy currents in the vacuum vessel and the structures contained therein.

摘要翻译： 超导磁性成像装置包括具有中心氦储存器（48）的真空容器（40），超导磁性线圈绕组（44）保持在超导温度下。 真空容器限定内部孔（42），在其内接收自屏蔽梯度线圈组件（14）和RF线圈（22）。 自屏蔽线圈组件包括限定成像区域（12）的内部成形器（60），其中接收患者的成像部分。 具有卷绕图案（62）的X和Y梯度线圈被结合到形成一体结构的前者（60）上。 z-梯度线圈（70）被安装到机械加强结构（72）上，以与x和y梯度线圈保持间隔开的关系，其间具有气隙（74）。 这有助于散发由施加到x和y梯度线圈的大电流脉冲产生的热量。 直径大于z-梯度线圈的外部成形器（80）被容纳在孔中并将内部构件支撑在其中。 X，Y和Z梯度次级或屏蔽线圈（82,84）被结合到外部成形器，用于防止由初级梯度线圈产生的梯度引起真空容器中的梯度涡流和其中所包含的结构。