公开(公告)号：EP0213858A3

公开(公告)日：1988-03-02

申请号：EP86306319

申请日：1986-08-15

Applicant: TECHNICARE CORPORATION

Inventor： Kramer, David Moses ,  Compton, Russell Allen ,  Yeung, Hong-Ning

IPC: G01N24/08

CPC classification number: G01R33/4835 ,  G01R33/4828

Abstract: In a magnetic resonance imaging system, a multiplexing technique is used to image volumetric regions by performing a number of scans within the recovery time of the spin systems. The multiple scans acquire signal information from sub-regional volumes by phase-encoding in the direction of the excitation gradient.

公开(公告)号：EP0086560B1

公开(公告)日：1986-10-08

申请号：EP83300212.4

申请日：1983-01-17

Applicant: TECHNICARE CORPORATION

Inventor： Compton, Russell Allen

IPC: G01N24/06 ,  G01N24/08 ,  H01F5/00

CPC classification number: H01F7/20 ,  G01R33/385

公开(公告)号：EP0134701B1

公开(公告)日：1989-11-08

申请号：EP84305284.6

申请日：1984-08-03

Applicant: TECHNICARE CORPORATION

Inventor： Compton, Russell Allen ,  Kramer, David Moses ,  Hinshaw, Waldo Stephen

IPC: G01N24/06 ,  G01N24/08

CPC classification number: G01R33/385 ,  G01R33/381

公开(公告)号：EP0142343B1

公开(公告)日：1989-01-25

申请号：EP84307746.2

申请日：1984-11-09

Applicant: TECHNICARE CORPORATION

Inventor： Compton, Russell Allen

IPC: G01N24/08

CPC classification number: G01R33/561 ,  G01R33/563

公开(公告)号：EP0134701A3

公开(公告)日：1986-02-05

申请号：EP84305284

申请日：1984-08-03

Applicant: TECHNICARE CORPORATION

Inventor： Compton, Russell Allen ,  Kramer, David Moses ,  Hinshaw, Waldo Stephen

IPC: G01N24/06 ,  G01N24/08

CPC classification number: G01R33/385 ,  G01R33/381

Abstract: The null point in the gradient field of an NMR imaging system is offset from its nominal position in the static magnetic field by application of a bias field to the gradient field. The bias field produces a substantially uniform offset in the field intensity at every point in the gradient field. Alternatively, null point offset may be achieved by controll- ably superimposing two gradient fields of separately located null points.

公开(公告)号：EP0142343A3

公开(公告)日：1986-04-16

申请号：EP84307746

申请日：1984-11-09

Applicant: TECHNICARE CORPORATION

Inventor： Compton, Russell Allen

IPC: G01N24/08

CPC classification number: G01R33/561 ,  G01R33/563

Abstract: The effects of motion in a given direction of particles being imaged in an NMR imaging system are substantially reduced by using gradients in the given direction produced by gradient pulse sequences which exhibit a zero value first moment relative to the point in time at which phase determination of the particles occurs. This point in time is generally taken at the time at which the longitudinal magnetization is translated to the transverse plane, as that is the phase reference for the NMR signals produced by the particles.

公开(公告)号：EP0086560A1

公开(公告)日：1983-08-24

申请号：EP83300212.4

申请日：1983-01-17

Applicant: TECHNICARE CORPORATION

Inventor： Compton, Russell Allen

IPC: G01N24/06 ,  G01N24/08 ,  H01F5/00

CPC classification number: H01F7/20 ,  G01R33/385

Abstract: Apparatus for imposing a gradient magnetic field intensity on a static magnetic field intensity in a nuclear- magnetic-resonance (NMR) system. The gradient field has a predetermined error relationship with respect to a desired characteristic of the gradient field within a selected region. The selected region is substantially smaller in volume than the volume «enclosed» by a surface or surfaces on which electrical conductors are distributed to generate the gradient field. The surface current densities in a grid-like pattern of differential areas on the surfaces are chosen such that, within the selected region, the predetermined error relationship results. The gradient field intensity outside of the selected region generally does not have the characteristic desired within the region. The predetermined error relationship can be established in a linearly-varying field intensity in a spherical volume enclosed by a cylindrical surface. Generally hyperbolically-shaped electrical coils on the cylindrical surface can provide surface current densities required for a constant transverse-gradient (a linearly varying magnetic field intensity in a direction transverse to the axis of the cylinder).

公开(公告)号：EP0204569A3

公开(公告)日：1988-03-09

申请号：EP86304287

申请日：1986-06-05

Applicant: TECHNICARE CORPORATION

Inventor： Kramer, David Moses ,  Strenk, Lawrence Matthew ,  Compton, Russell Allen ,  Murdoch, James Bryce

IPC: G01N24/08

CPC classification number: G01R33/482 ,  G01R33/56554

Abstract: The present invention provides nuclear magnetic resonance apparatus for producing resonance information in the form of first and second spin echo signals, comprising:
means for applying a static magnetic field to a subject being examined; means for applying a first radio frequency signal to said subject for inducing nuclear magnetic resonance information signals; means for applying a second radio frequency signal to said subject for generating spine cho signals at the end of a first predetermined time interval following said first radio frequency signal; and means for applying a third radio frequency signal to said subject for generating spine cho signals at the end of a second predetermined time interval following said first radio frequency signal, which second predetermined time interval is not harmonically related in duration to the duration of said first predetermined time interval.

公开(公告)号：EP0219206A3

公开(公告)日：1987-09-16

申请号：EP86306320

申请日：1986-08-15

Applicant: TECHNICARE CORPORATION

Inventor： Compton, Russell Allen ,  Keller, John Timothy ,  McBride, Thomas Robert ,  Kramer, David Moses

IPC: A61B05/05 ,  G01N24/00

CPC classification number: G01R33/583

Abstract: In a magnetic resonance imaging system, the same reference signal is used for both radio frequency transmission and phase sensitive detection. The use of the same reference signal for both transmission and reception prevents phase unlock between the two events. However, this technique results in variation in the demodulated, frequency encoded information, which is corrected by digitally filtering the received signal information as a function of the demodulation frequency used.

公开(公告)号：EP0142343A2

公开(公告)日：1985-05-22

申请号：EP84307746.2

申请日：1984-11-09

Applicant: TECHNICARE CORPORATION

Inventor： Compton, Russell Allen

IPC: G01N24/08

CPC classification number: G01R33/561 ,  G01R33/563

Abstract: The effects of motion in a given direction of particles being imaged in an NMR imaging system are substantially reduced by using gradients in the given direction produced by gradient pulse sequences which exhibit a zero value first moment relative to the point in time at which phase determination of the particles occurs. This point in time is generally taken at the time at which the longitudinal magnetization is translated to the transverse plane, as that is the phase reference for the NMR signals produced by the particles.