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US5347216A
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Fast NMR image acquisition with spectrally selective inversion pulse
Assignee: General Electric Co
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Filing: 1992-06-23
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Granted: 1994-09-13
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Expires: 2012-06-23
Abstract
Abstract An NMR system performs a 3DFT scan using a set of steady-state free precession (SSFP) pulse sequences. A contrast preparation pulse sequence precedes each series of SSFP pulse sequences employed to acquire one plane through the three-dimensional space, and it includes a spectrally selective RF inversion pulse tuned to fat or water. The sequence is repeated without any magnetization recovery delays until all the planes have been acquired.
Inventors
- 👤 Thomas K. Foo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:28
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/4828; G01R33/54; G01R33/56; G01R33/561
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
138 words
In an NMR system, a method for conducting a scan comprised of a set of steady-state free precession pulse sequences in which a magnetic field gradient is stepped through a corresponding set of values to acquire NMR data from which an image is reconstructed, the steps comprising: a) performing a contrast preparation pulse sequence which includes producing a spectrally selective RF inversion pulse which is tuned to the Larmor frequency of a selected spin species to be suppressed in the reconstructed image; b) performing a SSFP pulse sequence series in which a subset of said set of steady-state free precession pulse sequences are performed to acquire a portion of the NMR data; and c) repeating steps a) and b) until all steady-state free precession pulse sequences in said set have been performed without any significant recovery period therebetween.
Claim 2
Dependent Claim
138 words
In an NMR system, a method for conducting a scan comprised of a set of steady-state free precession pulse sequences in which a magnetic field gradient is stepped through a corresponding set of values to acquire NMR data from which an image is reconstructed, the steps comprising: a) performing a contrast preparation pulse sequence which includes producing a spectrally selective RF inversion pulse which is tuned to the Larmor frequency of a selected spin species to be suppressed in the reconstructed image; b) performing a SSFP pulse sequence series in which a subset of said set of steady-state free precession pulse sequences are performed to acquire a portion of the NMR data; and c) repeating steps a) and b) until all steady-state free precession pulse sequences in said set have been performed without any significant recovery period therebetween.
Claim 3
Dependent Claim
15 words
The method as recited in claim 1 in which the selected spin species is fat.
Claim 4
Dependent Claim
15 words
The method as recited in claim 1 in which the selected spin species is water.
Claim 5
Dependent Claim
52 words
The method as recited in claim 1 in which the NMR data is a 3DFT data set, in which each steady-state free precession pulse sequence includes a second magnetic field gradient, and in which step c) includes incrementing the value of the second magnetic field gradient before repeating steps a) and b).
References Cited (Backward Citations)
US5055790A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-09-12 | 1998-03-14 | 1998-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-12 | 2002-03-14 | 2002-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-12 | 2006-03-14 | 2006-09-13 | $7700.00 | Window Closed / Lapsed |