EP0204569A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Non-harmonic NMR spin echo imaging
Assignee: Siemens AG
•
Filing: 1986-06-05
•
Granted: —
•
Expires: 2006-06-05
Abstract
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.
Inventors
- 👤 David Moses Kramer
- 👤 Lawrence Matthew Strenk
- 👤 Russell Allen Compton
- 👤 James Bryce Murdoch
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 14:49
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/4818; G01R33/482; G01R33/54; G01R33/56; G01R33/565; G01R33/56554
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
132 words
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 spin echo 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 spin echo 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.
Claim 2
Dependent Claim
132 words
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 spin echo 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 spin echo 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.
Claim 3
Dependent Claim
23 words
Tne nuclear magnetic resonance apparatus of claim 1, wherein the second predetermined time interval is not equal to twice said predetermined time interval.
Claim 4
Dependent Claim
26 words
The nuclear magnetic resonance apparatus of claim 1 or claim 2, wherein said second and third radio frequency signals are each 180° inverting radio frequency pulses.
Claim 5
Dependent Claim
63 words
The nuclear magnetic resonance apparatus of any one of claims 1 to 3, wherein said first radio frequency signal is a 90° pulse. The nuclear magnetic resonance apparatus of any one of claims 1 to 4 further comprising gradient field apparatus for imposing selected gradient fields on said subject during said second predetermined time interval to spatially encode said generated spin echo signals.
Claim 6
Dependent Claim
34 words
The nuclear magnetic resonance apparatus of any one of claims 1 to 5 wherein said duration of said second predetermined time interval is more than twice the duration of said first predetermined time interval.
Claim 7
Dependent Claim
90 words
The nuclear magnetic resonance apparatus of any one of claims 1 to 6 wherein the means for applying 9 third radio frequency signal to said subject is adapted to generate a plurality of spin echo signals including at least one undesired spin echo signal, and a desired spin echo signal occurring after the second predetermined interval period following said first radio frequency signal, and wherein said first and second time intervals are chosen so that said desired and undesired spin echo signals are substantially nonoverlapping in their times of occurrence.
Claim 8
Dependent Claim
49 words
The nuclear magnetic resonance apparatus of claim 7, wherein the time of occurrence of said undesired spin echo signal is related to the time of occurrence of a radio frequency signal applied following said first radio frequency signal and prior to the application of said third radio frequency signal.
Claim 9
Dependent Claim
42 words
The nuclear magnetic resonance apparatus of claim 7 or claim 8, wherein said radio frequency signal applying means applies signals with differing phase relationships, whereby repetitively generated undesired spin echo signals will exhibit phases causing signal cancellation when such signals are combined.
Claim 10
Dependent Claim
101 words
The nuclear magnetic resonance apparatus of any one of claims 1 to 9, which is adapted to provide repetitive sequences of said first, second and third radio frequency signals, each of said signals being of a predetermined phase, and which further comprises means for altering the phase of at least one of said first, second and third radio frequency signals in consecutive repetitive sequences, whereby at least one spin echo signal generated by one sequence of signals will exhibit a different phase than a corresponding spin echo signal generated in the preceding sequence of signals following said third radio frequency signal.
References Cited (Backward Citations)
EP0098479A2
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.