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Method for recording spin resonance spectra

Assignee: University of Queensland
•
Filing: 1990-04-27
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Granted: 1992-11-24
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Expires: 2010-04-27
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Abstract

Abstract A method serving for recording spin resonance spectra of test samples having at least two groups (CH 3 , CH) of nuclei of the same kind and of substantially identical chemical shift, comprises the step of suppressing the signal of the second group (CH) for the purpose of obtaining an isolated image of the signal of the first group (CH 3 ). To this end, a pulse sequence of four r.f. pulses, preferably 90° r.f. pulses (10, 12, 13, 14), are irradiated upon the sample. The first r.f. pulse (10) is a soft pulse, selective for the nuclei of the first group (CH 3 ). The second r.f. pulse (12) is a soft pulse, selective for the nuclei of the second group (CH), and causes the magnetizations of the nuclei of the first group (CH 3 ) and of the second group (CH) to be transferred, at least in part, to a state of multiple-quantum coherence. Immediately following the second r.f. pulse (12) the third r.f. pulse (13), being at least one hard pulse, is irradiated upon the sample, and is adjusted in such a way that the multiple-quantum coherence is transferred to a correlated z-order state. A dephased magnetic gradient field pulse (15) is exerted upon the sample (30) in the interval τ HS between the third r.f. pulse (13) and the fourth r.f. pulse (14). The fourth r.f. pulse (14) is a soft pulse, selective for the nuclei of the first group (CH 3 ). It is adjusted in such a way that the correlated z-order state is re-transferred to a state of single-quantum coherence of the nuclei of the second group (CH). Thereafter one detects the resonance signal of the nuclei of the first group (CH 3 ).

Inventors

  • 👤 David M. Doddrell
  • 👤 Grahmam J. Galloway
  • 👤 Ian M. Brereton

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 18:02
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/46; G01R33/4608; G01R33/48; G01R33/483; G01R33/4833

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 306 words
A method of recording spin resonance spectra of test samples having at least a first and a second group (CH 3 , CH) of nuclei of the same kind and of substantially identical chemical shift, and for suppressing signals of said second group (CH) for the purpose of obtaining an isolated signal of said first group (CH 3 ), the method comprising the steps of: a) irradiating a pulse sequence of a first, a second, a third and a fourth r.f. pulse, preferably 90° r.f. pulses, upon the sample, wherein i) said first r.f. pulse is a soft pulse being selective for the nuclei of said first group (CH 3 ); ii) said second r.f. pulse is a soft pulse being selective for the nuclei of said second group (CH), said second r.f. pulse being adjusted in such a way that the magnetizations of the nuclei of said first group (CH 3 ) and of said second group (CH) are at least partially transferred to a state of multiple-quantum coherence; iii) immediately following said second r.f. pulse, said third r.f. pulse, being at least one hard pulse, is irradiated upon said sample, and is adjusted in such a way that said multiple-quantum coherence is transferred to a correlated z-order state; iv) a dephasing magnetic gradient field pulse is exerted upon said sample in an interval τHS between said third r.f. pulse and said fourth r.f. pulse, and v) said fourth r.f. pulse is a soft pulse being selective for the nuclei of said first group (CH 3 ), said fourth r.f. pulse being adjusted in such a way that said multiple-quantum coherence is re-transferred to a state of single-quantum coherence of the nuclei of said first group (CH 3 ); and b) thereafter detecting resonance signals of the nuclei of said first group (CH 3 ).
Claim 2
Independent Claim 306 words
A method of recording spin resonance spectra of test samples having at least a first and a second group (CH 3 , CH) of nuclei of the same kind and of substantially identical chemical shift, and for suppressing signals of said second group (CH) for the purpose of obtaining an isolated signal of said first group (CH 3 ), the method comprising the steps of: a) irradiating a pulse sequence of a first, a second, a third and a fourth r.f. pulse, preferably 90° r.f. pulses, upon the sample, wherein i) said first r.f. pulse is a soft pulse being selective for the nuclei of said first group (CH 3 ); ii) said second r.f. pulse is a soft pulse being selective for the nuclei of said second group (CH), said second r.f. pulse being adjusted in such a way that the magnetizations of the nuclei of said first group (CH 3 ) and of said second group (CH) are at least partially transferred to a state of multiple-quantum coherence; iii) immediately following said second r.f. pulse, said third r.f. pulse, being at least one hard pulse, is irradiated upon said sample, and is adjusted in such a way that said multiple-quantum coherence is transferred to a correlated z-order state; iv) a dephasing magnetic gradient field pulse is exerted upon said sample in an interval τHS between said third r.f. pulse and said fourth r.f. pulse, and v) said fourth r.f. pulse is a soft pulse being selective for the nuclei of said first group (CH 3 ), said fourth r.f. pulse being adjusted in such a way that said multiple-quantum coherence is re-transferred to a state of single-quantum coherence of the nuclei of said first group (CH 3 ); and b) thereafter detecting resonance signals of the nuclei of said first group (CH 3 ).
Claim 3
Dependent Claim 16 words
The method of claim 1, wherein said sample is a lactate sample or an ethanol sample.
Claim 4
Dependent Claim 37 words
The method of claim 1, wherein said first r.f. pulse is in x-phase, said second r.f. pulse is in y-phase, and said third r.f. pulse is in y-phase, and said fourth r.f. pulse is again in x-phase.
Claim 5
Dependent Claim 31 words
The method of claim 1, wherein a first 180° r.f. pulse is irradiated upon said sample, at the middle of a time interval between said first and said second r.f. pulses.
Claim 6
Dependent Claim 21 words
The method of claim 1, wherein a second 180° r.f. pulse is irradiated upon said sample following said fourth r.f. pulse.
Claim 7
Dependent Claim 45 words
The method of claim 1, wherein said sample is exposed, for volume-selective measurements, to a sequence of magnetic gradient field pulses of different coordinate directions (x, y, z), with at least one of said r.f. pulses of said pulse sequence being adjusted to be slice-selective.
Claim 8
Dependent Claim 50 words
The method of claim 1, wherein a time interval between said first r.f. pulse and said second r.f. pulse is selected to be equal to an odd multiple of the reciprocal value of twice the coupling constant (J) between said first group (CH 3 ) and said second group (CH).
Claim 9
Dependent Claim 14 words
The method of claim 6, wherein said volume-selective measurements are processed for imaging purposes.
Claim 10
Independent Claim 316 words
A method of recording spin resonance spectra of test samples having at least a first and a second group (CH 3 , CH) of nuclei of the same kind and of substantially identical chemical shift, and for suppressing signals of said second group (CH) for the purpose of obtaining an isolated signal of said first group (CH 3 ), the method comprising the steps of: a) irradiating a pulse sequence of a first, a second, a third and a fourth r.f. pulse, preferably 90° r.f. pulses, upon the sample, wherein i) said first r.f. pulse is a soft pulse being selective for the nuclei of said first group (CH 3 ); ii) said second r.f. pulse is a soft pulse being selective for the nuclei of said second group (CH), said second r.f. pulse being adjusted in such a way that the magnetizations of the nuclei of said first group (CH 3 ) and of said second group (CH) are at least partially transferred to a state of multiple-quantum coherence; iii) immediately following said second r.f. pulse, said third r.f. pulse, being at least one hard pulse, is irradiated upon said sample, and is adjusted in such a way that said multiple-quantum coherence is transferred to a correlated z-order state; iv) a dephasing magnetic gradient field pulse is exerted upon said sample in an interval τHS between said third r.f. pulse and said fourth r.f. pulse, and v) said fourth r.f. pulse is a soft pulse being selective for the nuclei of said second group (CH), said fourth r.f. pulse being adjusted in such a way that said correlated z-order state is transferred by polarization transfer from the nuclei of said first group (CH 3 ) to a state of single-quantum coherence of the nuclei of said second group (CH); and b) thereafter detecting resonance signals of the nuclei of said first group (CH 3 ).
Claim 11
Independent Claim 316 words
A method of recording spin resonance spectra of test samples having at least a first and a second group (CH 3 , CH) of nuclei of the same kind and of substantially identical chemical shift, and for suppressing signals of said second group (CH) for the purpose of obtaining an isolated signal of said first group (CH 3 ), the method comprising the steps of: a) irradiating a pulse sequence of a first, a second, a third and a fourth r.f. pulse, preferably 90° r.f. pulses, upon the sample, wherein i) said first r.f. pulse is a soft pulse being selective for the nuclei of said first group (CH 3 ); ii) said second r.f. pulse is a soft pulse being selective for the nuclei of said second group (CH), said second r.f. pulse being adjusted in such a way that the magnetizations of the nuclei of said first group (CH 3 ) and of said second group (CH) are at least partially transferred to a state of multiple-quantum coherence; iii) immediately following said second r.f. pulse, said third r.f. pulse, being at least one hard pulse, is irradiated upon said sample, and is adjusted in such a way that said multiple-quantum coherence is transferred to a correlated z-order state; iv) a dephasing magnetic gradient field pulse is exerted upon said sample in an interval τHS between said third r.f. pulse and said fourth r.f. pulse, and v) said fourth r.f. pulse is a soft pulse being selective for the nuclei of said second group (CH), said fourth r.f. pulse being adjusted in such a way that said correlated z-order state is transferred by polarization transfer from the nuclei of said first group (CH 3 ) to a state of single-quantum coherence of the nuclei of said second group (CH); and b) thereafter detecting resonance signals of the nuclei of said first group (CH 3 ).
Claim 12
Dependent Claim 16 words
The method of claim 9, wherein said sample is a lactate sample or an ethanol sample.
Claim 13
Dependent Claim 36 words
The method of claim 9, wherein said first r.f. pulse is in x-phase, said second r.f. pulse is in y-phase, said third r.f. pulse is in y-phase, and said fourth r.f. pulse is again in x-phase.
Claim 14
Dependent Claim 31 words
The method of claim 9, wherein a first 180° r.f. pulse is irradiated upon said sample, at the middle of a time interval between said first and said second r.f. pulses.
Claim 15
Dependent Claim 21 words
The method of claim 9, wherein a second 180° r.f. pulse is irradiated upon said sample following said fourth r.f. pulse.
Claim 16
Dependent Claim 45 words
The method of claim 9, wherein said sample is exposed, for volume-selective measurements, to a sequence of magnetic gradient field pulses of different coordinate directions (x, y, z), with at least one of said r.f. pulses of said pulse sequence being adjusted to be slice-selective.
Claim 17
Dependent Claim 50 words
The method of claim 9, wherein a time interval between said first r.f. pulse and said second r.f. pulse is selected to be equal to an odd multiple of the reciprocal value of twice the coupling constant (J) between said first group (CH 3 ) and said second group (CH).
Claim 18
Dependent Claim 14 words
The method of claim 6, wherein said volume-selective measurements are processed for imaging purposes.

References Cited (Backward Citations)

US4238735A Cited
US4680546A Cited
US4703270A Cited
US4972147A Cited
US5081417A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-11-24 1996-05-25 1996-11-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-11-24 2000-05-25 2000-11-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-11-24 2004-05-25 2004-11-24 $7700.00 Window Closed / Lapsed

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