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Patent US5588431A successfully refreshed from Google Patents.
US5588431A
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Inversion recovery MRI
Assignee: Leland Stanford Junior University
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Filing: 1995-08-17
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Granted: 1996-12-31
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Expires: 2015-08-17
Abstract
Abstract Multiple inversion recovery flow imaging employs at least four spin inversion pulses following saturation of static nuclei spins to null nuclei in static material having different spin-lattice relaxation times (T 1 ) with the inversion pulses being spaced in time to substantially reduce the longitudinal magnetization of the T 1 species present. The saturation of static nuclei spins includes applying a sequence of saturation pulses with adjacent pulses being separated by a diphasing gradient to avoid refocusing coherence. The detection of signals includes applying at least one RF read-out pulse near the nulling point.
Inventors
- 👤 Sanjay Mani
- 👤 Dwight G. Nishimura
- 👤 Steven M. Conolly
- 👤 John M. Pauly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:48
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/563; G01R33/5635; A; A61; A61B; A61B5/00; A61B5/02; A61B5/026; A61B5/0263; G01R33/5602
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
69 words
A method of multiple inversion recovery imaging signal detection comprising the steps of a) placing an object to be imaged in a magnetic field, b) applying RF excitation to saturate static nuclei spins, c) applying at least four spin inversion pulses to null nuclei in static material having different spin-lattice relaxation times (T 1 ); and d) applying at least one read-out pulse and detecting emitted magnetic resonance signals.
Claim 2
Independent Claim
69 words
A method of multiple inversion recovery imaging signal detection comprising the steps of a) placing an object to be imaged in a magnetic field, b) applying RF excitation to saturate static nuclei spins, c) applying at least four spin inversion pulses to null nuclei in static material having different spin-lattice relaxation times (T 1 ); and d) applying at least one read-out pulse and detecting emitted magnetic resonance signals.
Claim 3
Dependent Claim
32 words
The method as defined by claim 1 wherein in step c) said spin inversion pulses are spaced in time to substantially reduce the longitudinal magnetization of the different T 1 species present.
Claim 4
Dependent Claim
30 words
The method as defined by claim 1 wherein step b) includes applying a sequence of saturation pulses with adjacent pulses being separated by a dephasing gradient to avoid refocusing coherence.
Claim 5
Dependent Claim
16 words
The method as defined by claim 3 wherein said sequence of saturation pulses includes five pulses.
Claim 6
Dependent Claim
41 words
The method as defined by claim 3 wherein step d) includes applying a plurality of RF read-out pulses with the low spatial frequency data being acquired near the null point, the detecting of emitted signals occurring after each RF read-out pulse.
Claim 7
Dependent Claim
41 words
The method as defined by claim 1 wherein step d) includes applying a plurality of RF read-out pulses with the low spatial frequency data being acquired near the null point, the detecting of emitted signals occurring after each RF read-out pulse.
Claim 8
Dependent Claim
62 words
Apparatus for multiple inversion recovery imaging signal detection comprising a) means applying a magnetic field through an object to be imaged, b) means applying RF excitation to saturate static nuclei spins, c) means applying at least four spin inversion pulses to null nuclei in static material having different spin-lattice relaxation times (T 1 ); and d) means detecting emitted magnetic resonance signals.
Claim 9
Dependent Claim
62 words
Apparatus for multiple inversion recovery imaging signal detection comprising a) means applying a magnetic field through an object to be imaged, b) means applying RF excitation to saturate static nuclei spins, c) means applying at least four spin inversion pulses to null nuclei in static material having different spin-lattice relaxation times (T 1 ); and d) means detecting emitted magnetic resonance signals.
Claim 10
Dependent Claim
34 words
Apparatus as defined by claim 7 wherein said means for applying at least four magnetic inversion pulses applies pulses spaced in time to substantially reduce the longitudinal magnetization at the various T 1 species.
Claim 11
Dependent Claim
32 words
Apparatus as defined by claim 7 wherein said means for applying RF excitation applies a sequence of saturation pulses with adjacent pulses being separated by a dephasing gradient to avoid refocusing coherence.
Claim 12
Dependent Claim
15 words
Apparatus as defined by claim 9 wherein said sequence of saturation pulses includes five pulses.
Claim 13
Dependent Claim
42 words
Apparatus as defined by claim 9 wherein said means for detecting emitted signals applies a plurality of RF read-out pulses with the low spatial frequency data acquired near the null point, the detecting of emitted signals occurring after each RF read-out pulse.
Claim 14
Dependent Claim
42 words
Apparatus as defined by claim 9 wherein said means for detecting emitted signals applies a plurality of RF read-out pulses with the low spatial frequency data acquired near the null point, the detecting of emitted signals occurring after each RF read-out pulse.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-12-31 | 2000-07-01 | 2000-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-31 | 2004-07-01 | 2004-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-31 | 2008-07-01 | 2008-12-31 | $7700.00 | Window Closed / Lapsed |