US4906932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
NMR spectroscopy and NMR imaging
Assignee: BTG International Ltd
•
Filing: 1988-06-30
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Granted: 1990-03-06
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Expires: 2008-06-30
Abstract
Abstract Undesired signals are eliminated using a shaped RF pulse comprising a region of random frequency components and a region of zero components to effectively eliminate signals from areas volumes or frequency bands which are not required.
Inventors
- 👤 Roger J. Ordidge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:36
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/446; G01R33/48; G01R33/54; G01R33/56
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
60 words
A method of eliminating NMR signals from unwanted frequency bands in NMR systems comprising (a) providing a shaped RF pulse comprising at least two regions of frequency bands of random frequency components between which at least one frequency band region of zero components is situated and (b) detecting the NMR signal output from the frequency band region of zero components.
Claim 2
Independent Claim
60 words
A method of eliminating NMR signals from unwanted frequency bands in NMR systems comprising (a) providing a shaped RF pulse comprising at least two regions of frequency bands of random frequency components between which at least one frequency band region of zero components is situated and (b) detecting the NMR signal output from the frequency band region of zero components.
Claim 3
Independent Claim
64 words
A method of accurate definition of a desired volume of material in NMR systems within a large sample by removal of unwanted signal comprising (a) applying a shaped RF pulse in conjunction with a linear magnetic field gradient which effectively randomizes the net longitudinal spin magnetization in all volumes outside the selected volume and (b) detecting the NMR signal output from the selected volume.
Claim 4
Independent Claim
64 words
A method of accurate definition of a desired volume of material in NMR systems within a large sample by removal of unwanted signal comprising (a) applying a shaped RF pulse in conjunction with a linear magnetic field gradient which effectively randomizes the net longitudinal spin magnetization in all volumes outside the selected volume and (b) detecting the NMR signal output from the selected volume.
Claim 5
Dependent Claim
26 words
A method as claimed in claim 2 wherein one shaped RF pulse and gradient is used to leave unperturbed a slice which includes the desired volume.
Claim 6
Dependent Claim
26 words
A method as claimed in claim 2 wherein two shaped RF pulses and gradients are used to leave unperturbed a column which includes the desired volume.
Claim 7
Dependent Claim
30 words
A method as claimed in claim 2 wherein three shaped RF pulses and gradients are used to leave unperturbed the desired volume which is thereby defined as a retanguloid volume.
Claim 8
Dependent Claim
34 words
A method as claimed in claim 2 in which the shaped RF pulse has spectral components which are random over a defined frequency band and has no spectral components in a specified frequency band.
Claim 9
Dependent Claim
20 words
A method as claimed in claim 6 in which the RF pulses and gradients provide NMR or chemical shift imaging.
Claim 10
Dependent Claim
22 words
A method as claimed in claim 2 in which each shaped RF pulse has spectral components which are random in phase only.
Claim 11
Dependent Claim
27 words
A method as claimed in claim 2 in which noise signals of any characteristic are used to generate the random spectral components of the shaped RF pulse.
Claim 12
Dependent Claim
34 words
A method as claimed in claim 2 in which the application of the shaped RF pulse is used in conjunction with a form of localized spatial techniques to provide an accurately defined localized volume.
References Cited (Backward Citations)
US4703267A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-05 | 1993-09-04 | 1994-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-05 | 1997-09-04 | 1998-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-05 | 2001-09-04 | 2002-03-06 | $7700.00 | Window Closed / Lapsed |