US5339035A
Expired / Lapsed
US
⏱️ 0.0 years remaining
MR imaging with rectangular magnetization transfer pulse
Assignee: General Electric Co
•
Filing: 1993-05-07
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Granted: 1994-08-16
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Expires: 2013-05-07
Abstract
Abstract An NMR scanner performs a series of pulse sequences from which NMR data is acquired and used to reconstruct an image. Image contrast is enhanced by magnetization transfer from short-T 2 spin species that are saturated by an off-resonance, substantially rectangular shaped RF saturation pulse applied during each pulse sequence.
Inventors
- 👤 Erika Schneider
- 👤 Matthew A. Bernstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:43
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/4818; G01R33/482; G01R33/54; G01R33/56; G01R33/563; G01R33/5605
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
122 words
A method of enhancing the contrast of an image produced from NMR data acquired during a scan in which a series of pulse sequences are executed to elicit NMR signals from long-T 2 spins in a subject at a selected Larmor resonant frequency, which comprises: applying a substantially rectangular shaped RF saturation pulse to the subject prior to the acquisition of said NMR data to substantially reduce the net magnetization of short-T 2 spins in the subject, the frequency of said substantially rectangular shaped RF saturation pulse being offset from said selected Larmor resonant frequency by an amount which prevents the substantially rectangular shaped RF saturation pulse from reducing the net magnetization of long-T 2 spins at said selected Larmor resonant frequency.
Claim 2
Independent Claim
122 words
A method of enhancing the contrast of an image produced from NMR data acquired during a scan in which a series of pulse sequences are executed to elicit NMR signals from long-T 2 spins in a subject at a selected Larmor resonant frequency, which comprises: applying a substantially rectangular shaped RF saturation pulse to the subject prior to the acquisition of said NMR data to substantially reduce the net magnetization of short-T 2 spins in the subject, the frequency of said substantially rectangular shaped RF saturation pulse being offset from said selected Larmor resonant frequency by an amount which prevents the substantially rectangular shaped RF saturation pulse from reducing the net magnetization of long-T 2 spins at said selected Larmor resonant frequency.
Claim 3
Dependent Claim
29 words
The method as recited in claim 1 in which one of said substantially rectangular shaped RF saturation pulses is applied during each of said pulse sequences in the series.
Claim 4
Dependent Claim
38 words
The method as recited in claim 1 which includes: applying a magnetic field gradient pulse to the subject following the application of the substantially rectangular shaped RF saturation pulse to dephase transverse magnetization of the long-T 2 spins.
Claim 5
Dependent Claim
26 words
The method as recited in claim 1 in which the substantially rectangular shaped RF saturation pulse is produced by filtering a rectangular shaped RF saturation pulse.
Claim 6
Dependent Claim
17 words
The method as recited in claim 4 in which the filtering is performed using a Fermi filter.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-08-15 | 1998-02-14 | 1998-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-15 | 2002-02-14 | 2002-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-15 | 2006-02-14 | 2006-08-16 | $7700.00 | Window Closed / Lapsed |