MRT imaging on the basis of conventional PPA reconstruction methods

    公开(公告)号:US20060261810A1

    公开(公告)日:2006-11-23

    申请号:US11409353

    申请日:2006-04-21

    IPC分类号: G01V3/00

    摘要: In a method for magnetic resonance imaging on the basis of a partially-parallel acquisition (PPA) reconstruction method and a magnetic resonance tomography apparatus, data for at least two two-dimensional slices of a patient are acquired (which two-dimensional slices are displaced in the direction of a slice-selection gradient (z-gradients) defining the slice-normal direction) with at least one data acquisition in k-space (which acquisition forms a partial data set) per slice with a number of component coils, with the sum of all partial data sets forming a complete data set in k-space. The coil sensitivities of each component coil are determined on the basis of the complete data set. At least one partial data set of each slice is completed with a PPA reconstruction method on the basis of the determined coil sensitivities. The completed slices in k-space are transformed into whole images in the spatial domain.

    Three-dimensional slice-selective multi-slice excitation method in MRT imaging
    2.
    发明授权
    Three-dimensional slice-selective multi-slice excitation method in MRT imaging 有权
    MRT成像中的三维切片选择多切片激发方法

    公开(公告)号:US07528601B2

    公开(公告)日:2009-05-05

    申请号:US12022274

    申请日:2008-01-30

    IPC分类号: G01V3/00 G06K9/00 G06K9/40

    摘要: In a method and apparatus for MRT imaging, data sets acquired from magnetic resonance signals of at least two limited spatial regions of a subject to be examined, (the spatial regions being displaced relative to one another along one spatial direction and overlapping in the respective edge region. Phase coding occurs in an inhomogeneous non-edge region, likewise in this spatial direction. For at least one of these spatial regions, a modulation function is determined that is limited to this entire spatial region and modulates the subject information. Foldovers in the overlap regions of the different spatial regions are calculated on the basis of the modulation function and the MRT images of the non-edge regions of the respective spatial regions are combined without foldovers in the spatial direction under consideration of the calculated foldings.

    摘要翻译: 在用于MRT成像的方法和装置中,从要检查的对象的至少两个有限空间区域的磁共振信号获取的数据集(空间区域沿着一个空间方向相对于彼此移位并且在相应边缘中重叠) 相位编码发生在不均匀的非边缘区域,同样在该空间方向上,对于这些空间区域中的至少一个,确定了限制于该整个空间区域并调制主题信息的调制函数。 基于调制函数计算不同空间区域的重叠区域,并且在考虑计算的折叠的情况下将各空间区域的非边缘区域的MRT图像在空间方向上组合而不进行叠合。

    MRT imaging on the basis of conventional PPA reconstruction methods
    3.
    发明授权
    MRT imaging on the basis of conventional PPA reconstruction methods 有权
    基于常规PPA重建方法的MRT成像

    公开(公告)号:US07511489B2

    公开(公告)日:2009-03-31

    申请号:US11409353

    申请日:2006-04-21

    IPC分类号: G01V3/00

    摘要: In a method for magnetic resonance imaging on the basis of a partially-parallel acquisition (PPA) reconstruction method and a magnetic resonance tomography apparatus, data for at least two two-dimensional slices of a patient are acquired (which two-dimensional slices are displaced in the direction of a slice-selection gradient (z-gradients) defining the slice-normal direction) with at least one data acquisition in k-space (which acquisition forms a partial data set) per slice with a number of component coils, with the sum of all partial data sets forming a complete data set in k-space. The coil sensitivities of each component coil are determined on the basis of the complete data set. At least one partial data set of each slice is completed with a PPA reconstruction method on the basis of the determined coil sensitivities. The completed slices in k-space are transformed into whole images in the spatial domain.

    摘要翻译: 在基于部分平行采集(PPA)重建方法和磁共振断层摄影装置的磁共振成像方法中,获取患者的至少两个二维切片的数据(该二维切片被置换 在定义切片法线方向的切片选择梯度(z-梯度)的方向上,每片具有多个分量线圈的k空间中的至少一次数据采集(其获取形成部分数据集),其中, 在k空间中形成完整数据集的所有部分数据集的总和。 根据完整的数据集确定各部件线圈的线圈灵敏度。 基于确定的线圈灵敏度,利用PPA重建方法完成每个切片的至少一个部分数据集。 在k空间中完成的切片被转换成空间域中的整个图像。

    THREE-DIMENSIONAL SLICE-SELECTIVE MULTI-SLICE EXCITATION METHOD IN MRT IMAGING
    4.
    发明申请
    THREE-DIMENSIONAL SLICE-SELECTIVE MULTI-SLICE EXCITATION METHOD IN MRT IMAGING 有权
    MRT成像中的三维选择性多点激活方法

    公开(公告)号:US20080180099A1

    公开(公告)日:2008-07-31

    申请号:US12022274

    申请日:2008-01-30

    IPC分类号: G01R33/483

    摘要: In a method and apparatus for MRT imaging, data sets acquired from magnetic resonance signals of at least two limited spatial regions of a subject to be examined, (the spatial regions being displaced relative to one another along one spatial direction and overlapping in the respective edge region. Phase coding occurs in an inhomogeneous non-edge region, likewise in this spatial direction. For at least one of these spatial regions, a modulation function is determined that is limited to this entire spatial region and modulates the subject information. Foldovers in the overlap regions of the different spatial regions are calculated on the basis of the modulation function and the MRT images of the non-edge regions of the respective spatial regions are combined without foldovers in the spatial direction under consideration of the calculated foldings.

    摘要翻译: 在用于MRT成像的方法和装置中,从要检查的对象的至少两个有限空间区域的磁共振信号获取的数据集(空间区域沿着一个空间方向相对于彼此移位并且在相应边缘中重叠) 相位编码发生在不均匀的非边缘区域,同样在该空间方向上,对于这些空间区域中的至少一个,确定了限制于该整个空间区域并调制主题信息的调制函数。 基于调制函数计算不同空间区域的重叠区域,并且在考虑计算的折叠的情况下将各空间区域的非边缘区域的MRT图像在空间方向上组合而不进行叠合。

    Method and apparatus for SAR reduction using B0 specific RF excitation

    公开(公告)号:US09709643B2

    公开(公告)日:2017-07-18

    申请号:US14076017

    申请日:2013-11-08

    IPC分类号: G01V3/00 G01R33/28 G01R33/483

    CPC分类号: G01R33/288 G01R33/4833

    摘要: A method for generation of a radio-frequency (RF) pulse for excitation of nuclear spins in a predetermined layer of a specimen for magnetic resonance imaging and a magnetic resonance imaging device for performing the method are provided. The method includes determining a variation of a magnetic field in a measuring volume, and defining a spectral frequency distribution of the RF pulse. The RF pulse with the spectral frequency distribution is configured to excite nuclear spins in the specimen. The nuclear spins are polarized by the magnetic field at a predetermined flip angle in the measuring volume under a boundary condition of a substantially minimum energy content. The method also includes generating the RF pulse with the defined spectral frequency distribution.

    Magnetic resonance method and system to generate an optimized MR image of an examination subject
    8.
    发明授权
    Magnetic resonance method and system to generate an optimized MR image of an examination subject 有权
    磁共振法和系统生成检查对象的优化MR图像

    公开(公告)号:US09229083B2

    公开(公告)日:2016-01-05

    申请号:US13247428

    申请日:2011-09-28

    申请人: Hans-Peter Fautz

    发明人: Hans-Peter Fautz

    摘要: A magnetic resonance method and system for generation of an optimized MR image of an examination subject operate as follows. A pulse sequence including a series of at least two RF pulses is radiated into the examination subject to generate at least one optimized signal, wherein the second and possibly every additional RF pulse is radiated before the effect of the first or a preceding RF pulse on the spin system in the examination subject has decayed. The radiated RF pulses are generated by parallel transmission coils. At least the signal resulting after the last radiated RF pulse of the pulse sequence is acquired. The pulse sequence is repeated with modified spatial coding until signals have been generated and acquired in a desired positional space. The optimized MR image per pulse sequence is calculated from at least one of the acquired signals.

    摘要翻译: 用于产生检查对象的优化MR图像的磁共振方法和系统如下操作。 包括一系列至少两个RF脉冲的脉冲序列被辐射到检查对象中以产生至少一个优化的信号,其中第二个可能的每个附加RF脉冲在第一个或之前的RF脉冲的影响之前被辐射 考试科目的旋转体系已经衰退。 辐射RF脉冲由并行传输线圈产生。 至少获得在脉冲序列的最后辐射RF脉冲之后产生的信号。 用修改的空间编码重复脉冲序列,直到在期望的位置空间中产生和获取信号。 从所获取的信号中的至少一个计算每个脉冲序列的优化的MR图像。

    Method and processor and magnetic resonance apparatus for designing RF pulses to mitigate off-resonance effects
    9.
    发明授权
    Method and processor and magnetic resonance apparatus for designing RF pulses to mitigate off-resonance effects 有权
    用于设计RF脉冲以减轻非共振效应的方法和处理器和磁共振装置

    公开(公告)号:US08866478B2

    公开(公告)日:2014-10-21

    申请号:US13181868

    申请日:2011-07-13

    摘要: In a magnetic resonance apparatus and operating method therefor, and in a processor that is programmed to design RF pulses for operating such a magnetic resonance apparatus, the RF pulses are designed to mitigate off-resonance effects caused by inhomogeneity of the basic (B0) magnetic field in the magnetic resonance apparatus. The RF pulses of a parallel transmit array are designed with different spatial phase distributions, that deviate from a constant phase from pulse-to-pulse, with the absolute value of the difference between respective spatial phase distributions of any two successively radiated RF pulses corresponding to the off-resonance that is caused by B0-inhomogeneity during the time between the radiation of the successive pulses. Additionally, or separately, currents supplied to the shim coils can be taken into account in the design of the RF pulses as an additional degree of freedom, with the shimming of the basic magnetic field produced by the shim currents deviating from shim currents designed to ideally produce a homogenous B0 field.

    摘要翻译: 在一种磁共振装置及其操作方法中,并且在被编程为设计用于操作这种磁共振装置的RF脉冲的处理器中,RF脉冲被设计成减轻由基本(B0)磁性的不均匀性引起的非共振效应 磁场。 平行发射阵列的RF脉冲被设计为具有不同的空间相位分布,其偏离了脉冲到脉冲的恒定相位,对应于任何两个相继辐射的RF脉冲的相应空间相位分布之间的差的绝对值 在连续脉冲的辐射期间由B0不均匀性引起的非共振。 此外,或者单独地,作为附加自由度,在RF脉冲的设计中可以考虑提供给垫片线圈的电流,同时由偏置电流产生的基本磁场的匀场偏离设计成理想的电流 产生均匀的B0场。

    Method and Apparatus for SAR Reduction Using B0 Specific RF Excitation
    10.
    发明申请
    Method and Apparatus for SAR Reduction Using B0 Specific RF Excitation 有权
    使用B0特定RF激励的SAR减少的方法和装置

    公开(公告)号:US20140132262A1

    公开(公告)日:2014-05-15

    申请号:US14076017

    申请日:2013-11-08

    IPC分类号: G01R33/36

    CPC分类号: G01R33/288 G01R33/4833

    摘要: A method for generation of a radio-frequency (RF) pulse for excitation of nuclear spins in a predetermined layer of a specimen for magnetic resonance imaging and a magnetic resonance imaging device for performing the method are provided. The method includes determining a variation of a magnetic field in a measuring volume, and defining a spectral frequency distribution of the RF pulse. The RF pulse with the spectral frequency distribution is configured to excite nuclear spins in the specimen. The nuclear spins are polarized by the magnetic field at a predetermined flip angle in the measuring volume under a boundary condition of a substantially minimum energy content. The method also includes generating the RF pulse with the defined spectral frequency distribution.

    摘要翻译: 提供了一种用于产生用于磁共振成像用试样的预定层中的核自旋激发的射频(RF)脉冲的方法和用于执行该方法的磁共振成像装置。 该方法包括确定测量体积中的磁场的变化,并且确定RF脉冲的频谱频率分布。 具有频谱分布的RF脉冲被配置为激发样品中的核自旋。 在基本上最小的能量含量的边界条件下,核自旋在测量体积中以预定翻转角的磁场进行极化。 该方法还包括以定义的频谱分布产生RF脉冲。