公开(公告)号：WO1990002342A1

公开(公告)日：1990-03-08

申请号：PCT/GB1989000950

申请日：1989-08-16

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  MEHDIZADEH, Mehrdad ,  MOLYNEAUX, David, A. ,  HOLLAND, G., Neil

IPC: G01R33/34

CPC classification number: G01R33/3678 ,  G01R33/34007 ,  G01R33/34046 ,  G01R33/341 ,  G01R33/3628

Abstract: A thin dielectric sheet (36) has a first or loop coil (30) defined on one surface thereof and a second or Helmholtz coil (32) defined on an obverse surface thereof. The dielectric sheet and associated coils may be laid flat (Fig. 3) or bent to match a selected curved surface of the subject (Fig. 6-8). The first and second coils are arranged symmetrically about an axis or plane of symmetry (34). The first coil has an associated magnetic field along a y-axis and the second coil has an associated magnetic field along the x-axis. Circuits (40) and (42) tune the first and second magnetic resonance coils to a preselected magnetic resonance frequency. Magnetic resonance signals of the selected frequency received by one of the coils are phase shifted 90 DEG by a phase shifting circuit (50) and combined with the unphase shifted signals from the other coil by a combining circuit (52). The combined signals are amplified (54) and conveyed to electronic image processing circuitry (E) of a magnetic resonance scanner.

Abstract translation: 薄介电片（36）具有限定在其一个表面上的第一或环形线圈（30）和限定在其正面上的第二或亥姆霍兹线圈（32）。 电介质片和相关联的线圈可以平放（图3）或弯曲以匹配被摄体的选定曲面（图6-8）。 第一和第二线圈围绕对称轴（34）对称地布置。 第一线圈具有沿着y轴的相关磁场，而第二线圈具有沿x轴的相关磁场。 电路（40）和（42）将第一和第二磁共振线圈调谐到预选的磁共振频率。 由一个线圈接收的选定频率的磁共振信号由相移电路（50）相移90°，并通过组合电路（52）与来自另一个线圈的单相移位信号组合。 组合的信号被放大（54）并传送到磁共振扫描器的电子图像处理电路（E）。

公开(公告)号：WO1987001201A1

公开(公告)日：1987-02-26

申请号：PCT/GB1986000459

申请日：1986-07-31

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  NAYLER, Graham, Leslie ,  PATTANY, Pradip, Mathuradas

IPC: G01N24/08

CPC classification number: G01R33/56509 ,  G01F1/716 ,  G01R33/482 ,  G01R33/54 ,  G01R33/56308 ,  G01R33/56316

Abstract: A main magnetic field coil (10) and control (12) cause a generally uniform main magnetic field through an image region. A resonance excitation control (22) causes an R.F. coil (20) to generate excitation pulses (100). A slice gradient control (32) and a read gradient control (34) cause a gradient coil (30) to generate complementary slice selection gradient profiles (112, 114) and complementary read gradient profiles (122, 124) in such a manner that the effective first moment in time is substantially zero. By time shifting a pulse in one or both of the slice selection and read gradient sequences (Figs. 3 and 4), resonating nuclei in the selected slice can be phase encoded. A transform algorithm (40) transforms field echo signals (102) received by the R.F. coil into image representations. A first memory (54) receives real and imaginary portions of the image representations when the read and slice selection gradients are not shifted and a second memory (56) receives the image representations when one or both of the read and slice selection gradients are time shifted. A phase difference map (70) is calculated (60) from the arctangent of phase difference values derived from the first and second images. The intensity of each pixel of the phase difference map varies with phase shift, hence velocity.

公开(公告)号：WO1987000923A1

公开(公告)日：1987-02-12

申请号：PCT/GB1986000457

申请日：1986-07-31

Applicant: PICKER INTERNATIONAL INC.

Inventor： PICKER INTERNATIONAL INC. ,  HAACKE, Mark, E. ,  KERSHAW, Carolyn, A. ,  PATRICK, John, L.

IPC: G01N24/08

CPC classification number: G01R33/5673 ,  G01R33/56509

Abstract: A portion of a subject (22) which is undergoing respiratory or other motion is disposed in an image region (20) to be examined. A respiratory or other motion monitor (50) monitors the cyclic respiratory motion and provides output signals indicative of chest expansion. A phase encoding gradient selector (60) selects the phase encoding radient that is to be applied by a gradient magnetic field controller (40) and coil (42). A central phase encoding gradient is selected corresponding to a chest relaxation extreme and minimum and maximum phase encoding gradients are selected corresponding to a chest expansion extreme (Fig. 2). Intermediate degrees of monitored physical movement cause the selection of corresponding intermediate phase encoding gradients. Resonance signals collected during each phase encoding gradient are Fourier or otherwise transformed (80) into a corresponding view. A filter (92) weights each view such that views closest to the central phase encoding gradient are weighted most heavily and views adjacent the minimum and maximum phase encoding gradients are weighted least heavily. The physical position of pixels within each view are scaled (94) to adjust each view in accordance with the degree of physical expansion. The weighted and scaled views are transformed into an image memory (120) for display on a video display (122) or the like.

Abstract translation: 正在进行呼吸或其他运动的受试者（22）的一部分被布置在待检查的图像区域（20）中。 呼吸或其他运动监测器（50）监测循环呼吸运动并提供指示胸部扩张的输出信号。 相位编码梯度选择器（60）选择由梯度磁场控制器（40）和线圈（42）施加的相位编码天线。 对应于胸部放松极值选择中心相位编码梯度，并且根据胸部扩张极限选择最小和最大相位编码梯度（图2）。 受监视的物理运动的中等程度导致相应的中间相位编码梯度的选择。 在每个相位编码梯度期间收集的共振信号是傅立叶变换或其他变换（80）到相应的视图。 滤波器（92）对每个视图进行加权，使得最接近中央相位编码梯度的视图被加权最大，并且邻近最小和最大相位编码梯度的视图被加权最小。 每个视图内的像素的物理位置被缩放（94），以根据物理扩展的程度调整每个视图。 加权和缩放视图被转换成用于在视频显示器（122）等上显示的图像存储器（120）。