US4068161A
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Gyromagnetic resonance spectroscopy employing spin echo spin-spin decoupling and two-dimensional spreading
Assignee: Varian Medical Systems Inc
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Filing: 1976-05-13
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Granted: 1978-01-10
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Expires: 1996-05-13
Abstract
Abstract A method of gyromagnetic resonance spectroscopy is disclosed which simplifies the resultant spectra by eliminating spin-spin coupling effects. The method is particularly useful for eliminating homonuclear spin-spin coupling effects. In the method, spin echo resonance of the resonators is obtained and the time elapsing between tipping of the resonators and detection of the resultant echo t 1 is changed from one measurement to the next. The resultant echos are measured at equal intervals of time t 2 . Echo resonance data is Fourier transformed from the time domain into the frequency domain to obtain spectral data in the frequency domain as a function of t 1 . A second Fourier transform of the resonance data is then effected to transform the spectral data into data which is a function of both ω 1 and ω 2 where ω 1 and ω 2 are each related to 1/t 1 and 1/t 2 , respectively. The spectral data in the ω 1 -ω 2 plane is then projected at 45° to the ω 2 and ω 1 axes to derive spectral data free of spin-spin coupling effects. The data may also be projected perpendicular to and onto the ω 1 axis to obtain a J coupling spectrum.
Inventors
- 👤 Richard R. Ernst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:50
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/46; G01R33/4633; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/842; Y10S505/843; Y10S505/844
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
204 words
In a method of gyromagnetic resonance spectroscopy, operative upon an assembly of first and second groups of gyromagnetic resonators immersed in a polarizing magnetic field wherein the magnetization vectors of said gyromagnetic resonators precess about said polarizing magnetic field, said first and second groups being coupled through spin-spin interaction, said spin-spin interaction causing a defocusing effect whereby the phase coherence of precession among said resonators is progressively lost, the steps of: periodically tipping the magnetization vectors of said spin-spin coupled first and second groups of gyromagnetic resonators with respect to said polarizing magnetic field; periodically flipping the magnetization vectors of said precessing resonators relative to the direction of the polarizing magnetic field for reversing the defocusing effect of the precession effect of the precession of said resonators about the polarizing magnetic field to obtain spin echo resonance of said resonators; periodically detecting the spin echo resonance of said resonators; and changing the period of time t between tipping of said magnetization vectors and detection of the spin echo resonance for a series of said periodically detected spin echo resonances to obtain detected gyromagnetic resonance data about said first and second spin-spin coupled groups of resonators from which to derive simplified gyromagnetic resonance spectral data.
Claim 2
Dependent Claim
204 words
In a method of gyromagnetic resonance spectroscopy, operative upon an assembly of first and second groups of gyromagnetic resonators immersed in a polarizing magnetic field wherein the magnetization vectors of said gyromagnetic resonators precess about said polarizing magnetic field, said first and second groups being coupled through spin-spin interaction, said spin-spin interaction causing a defocusing effect whereby the phase coherence of precession among said resonators is progressively lost, the steps of: periodically tipping the magnetization vectors of said spin-spin coupled first and second groups of gyromagnetic resonators with respect to said polarizing magnetic field; periodically flipping the magnetization vectors of said precessing resonators relative to the direction of the polarizing magnetic field for reversing the defocusing effect of the precession effect of the precession of said resonators about the polarizing magnetic field to obtain spin echo resonance of said resonators; periodically detecting the spin echo resonance of said resonators; and changing the period of time t between tipping of said magnetization vectors and detection of the spin echo resonance for a series of said periodically detected spin echo resonances to obtain detected gyromagnetic resonance data about said first and second spin-spin coupled groups of resonators from which to derive simplified gyromagnetic resonance spectral data.
Claim 3
Dependent Claim
60 words
The method of claim 1 wherein the step of periodically detecting the spin echo resonance of said resonators includes the step of detecting respective ones of said spin echo resonances at a plurality m of time displaced intervals t 2 to derive sets of spin echo resonance data as a function of n values of the time t 1 .
Claim 4
Dependent Claim
70 words
The method of claim 2 including the step of Fourier transforming said sets of spin echo resonance data with respect to t 2 from the time domain into the frequency domain to obtain sets of spin echo resonance data in the frequency domain ω 2 as a function of the time t 1 and as a function of ω 2 , where ω 2 is related to 1/t 2 .
Claim 5
Dependent Claim
77 words
The method of claim 3 including the step of Fourier transforming the Fourier transformed sets of spin echo resonance data in the frequency domain with respect to t 1 into corresponding sets of spin echo resonances in the frequency domain as a function of the frequency ω 1 which is related to the inverse of t 1 to obtain sets of spin echo resonance spectral data as a function of both ω 1 and ω 2 .
Claim 6
Dependent Claim
45 words
The method of claim 4 including the steps of projecting said sets of spin echo resonance data as a function of both ω 1 and ω 2 onto an axis in the ω 1 , ω 2 plane to obtain simplified gyromagnetic resonance spectral data.
Claim 7
Dependent Claim
36 words
The method of claim 5 wherein said ω 1 and ω 2 axes are orthogonal and wherein said projection is onto the ω 2 axis along a line at approximately 45° to said ω 2 axis.
Claim 8
Dependent Claim
32 words
The method of claim 5 wherein said ω 1 and ω 2 axes are orthogonal to each other and said projection is taken generally orthogonal to and onto said ω 1 axis.
Claim 9
Dependent Claim
203 words
In a gyromagnetic resonance spectrometer, operative upon an assembly of first and second groups of gyromagnetic resonators immersed in a polarizing magnetic field wherein the magnetization vectors of said gyromagnetic resonators precess about said polarizing magnetic field, said first and second groups being coupled through spin-spin interaction, said spin-spin interaction causing a defocusing effect whereby the phase coherence of precession among said resonators is progressively lost: means for periodically tipping the magntization vectors of said spin-spin coupled first and second groups of gyromagnetic resonators with respect to said polarizing magnetic field; means for periodically flipping the magnetization vectors of said precessing resonantors relative to the direction of the polarizing magnetic field for reversing the defocusing effect of the precession of said resonators about said polarizing magnetic field to obtain spin echo resonances of said resonators; means for periodically detecting the spin echo resonance of said resonators; and means for changing the period of time t between tipping of said magnetization vectors and detection of the spin echo resonance for a series of said periodically detected spin echo resonances to obtain detected gyromagnetic resonance data about said first and second spin-spin coupled groups of resonators from which to derive simplified gyromagnetic resonance spectral data.
Claim 10
Dependent Claim
203 words
In a gyromagnetic resonance spectrometer, operative upon an assembly of first and second groups of gyromagnetic resonators immersed in a polarizing magnetic field wherein the magnetization vectors of said gyromagnetic resonators precess about said polarizing magnetic field, said first and second groups being coupled through spin-spin interaction, said spin-spin interaction causing a defocusing effect whereby the phase coherence of precession among said resonators is progressively lost: means for periodically tipping the magntization vectors of said spin-spin coupled first and second groups of gyromagnetic resonators with respect to said polarizing magnetic field; means for periodically flipping the magnetization vectors of said precessing resonantors relative to the direction of the polarizing magnetic field for reversing the defocusing effect of the precession of said resonators about said polarizing magnetic field to obtain spin echo resonances of said resonators; means for periodically detecting the spin echo resonance of said resonators; and means for changing the period of time t between tipping of said magnetization vectors and detection of the spin echo resonance for a series of said periodically detected spin echo resonances to obtain detected gyromagnetic resonance data about said first and second spin-spin coupled groups of resonators from which to derive simplified gyromagnetic resonance spectral data.
Claim 11
Dependent Claim
59 words
The apparatus of claim 8 wherein said means for periodically detecting the spin echo resonance of said resonators includes means for detecting respective ones of said echo resonances at a plurality m of time displaced intervals of t 2 to derive sets of spin echo resonance data as a function of n values of the time t 1 .
Claim 12
Dependent Claim
68 words
The apparatus of claim 9 including means for Fourier transforming said sets of spin echo resonance data with respect to t 2 from the time domain into the frequency domain to obtain sets of spin echo resonance data in the frequency domain ω 2 as a function of the time t 1 and as a function of ω 2 where ω 2 is related to 1/t 2 .
Claim 13
Dependent Claim
78 words
The apparatus of claim 10 including means for Fourier transforming the Fourier transform sets of spin echo resonance data in the frequency domain with respect to t 1 in the corresponding sets of spin echo resonance data in the frequency domain as a function of the frequency ω 1 which is related to the inverse of t 1 to obtain sets of spin echo resonance spectral data as a function of both ω 1 and ω 2 .
Claim 14
Dependent Claim
44 words
The apparatus of claim 11 including means for projecting said sets of spin echo resonance data as a function of both ω 1 and ω 2 onto an axis in the ω 1 , ω 2 plane to obtain simplified gyromagnetic resonance spectral data.
Claim 15
Dependent Claim
37 words
The apparatus of claim 12 wherein said ω 1 and ω 2 axes are orthogonal and wherein said projection is taken onto the ω 2 axis along a line at approximately 45° to said ω 2 axis.
Claim 16
Dependent Claim
32 words
The apparatus of claim 12 wherein said ω 1 and ω 2 axes are orthogonal to each other and said projection is taken generally orthogonal to and onto said ω 1 axis.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-09 | 1981-07-11 | 1982-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-09 | 1985-07-11 | 1986-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-09 | 1989-07-11 | 1990-01-10 | $7700.00 | Window Closed / Lapsed |