Methods of producing images by NMR techniques
    2.
    发明授权
    Methods of producing images by NMR techniques 失效
    通过NMR技术制作图像的方法

    公开(公告)号:US4651095A

    公开(公告)日:1987-03-17

    申请号:US636857

    申请日:1984-08-01

    CPC分类号: G01R33/482

    摘要: A set of NMR free induction signals generated in nuclei in a sample are recorded in the presence of a magnetic field gradient to a static magnetic field in which the sample is positioned. Prior to recording a magnetic field gradient orthogonal to the said gradient is applied to phase-encode the signals. The individual signals of a set are differentiated by being recorded after different time integrals of the phase encoding gradient. The magnitudes of successive time integrals have a non-monotonic relationship with each other so that sufficient signal data is recorded to enable the Fourier transform operation to commence before half or less of the set of signals has been recorded. Preferably the relationship between the magnitudes of successive time integrals corresponds to a numerical sequence represented by a monotonic sequence of binary numbers re-arranged in bit-reversed order.

    摘要翻译: 在存在磁场梯度的情况下,将样品中的核中产生的一组NMR自由感应信号记录到样品所在的静态磁场。 在记录之前,将与所述梯度正交的磁场梯度应用于信号的相位编码。 通过在相位编码梯度的不同时间积分之后被记录来区分集合的各个信号。 连续时间积分的大小彼此之间具有非单调关系,从而记录足够的信号数据,以使傅里叶变换操作在已经记录了该组信号的一半以下之前开始。 优选地,连续时间积分的大小之间的关系对应于以比特反转顺序重新排列的二进制数的单调序列表示的数字序列。

    Nuclear magnetic resonance imaging method
    3.
    发明授权
    Nuclear magnetic resonance imaging method 失效
    核磁共振成像法

    公开(公告)号:US4607223A

    公开(公告)日:1986-08-19

    申请号:US520231

    申请日:1983-08-04

    CPC分类号: G01R33/4822 G01R33/5616

    摘要: A method of deriving three dimensional image information from an object using nuclear magnetic resonance signals is described. The method comprises subjecting the object to a continuous, static magnetic field and carrying out the following set of sequential steps.1. Exciting nuclear spins in a volume;2. applying non-aligned first, second and third gradients of the magnetic field;3. causing the spins to rephase periodically in the presence of the first gradient;4. phase encoding the spins in the direction of the second gradient prior to every read-out of the rephased FIS from the object;and then successively repeating the above set of steps with different values of gradient of the third gradient (G.sub.z.sup.(2)), there being a recovery interval between the repetition of successive sets of steps.

    摘要翻译: 描述了使用核磁共振信号从对象导出三维图像信息的方法。 该方法包括使物体经受连续的静态磁场并执行以下一组顺序步骤。 激动的核旋转在一个卷; 2.应用磁场的非对准的第一,第二和第三梯度; 3.在第一梯度的存在下,使自旋重新定型; 4.在从对象中读出已重定位的FIS之前,在第二梯度的方向上相位编码自旋; 然后用不同的第三梯度(Gz(2))的梯度连续地重复上述步骤,在重复连续的步骤组之间存在恢复间隔。