US4968935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective rephasing of NMR signals to suppress motion artifacts
Assignee: Mayo Clinic in Florida
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Filing: 1989-09-11
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Granted: 1990-11-06
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Expires: 2009-09-11
Abstract
Abstract Motion artifacts are selectively suppressed in an image by correcting only the NMR data in the central views. The peripheral views are not corrected with the result that motion artifacts produced by large objects in the image are suppressed while motion artifacts produced by small objects are not. Consequently, the interior of small blood vessels remain darker in the reconstructed image.
Inventors
- 👤 Richard L. Ehman
- 👤 Joel P. Felmlee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:59
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/565; G01R33/56509
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
80 words
In a method for correcting an NMR data set to suppress image artifacts caused by motion, the improvement comprising: applying the corrective method only to views in a selected central region of the NMR data set; and reconstructing an image from the selectively corrected NMR data set using a Fourier transformation to produce an image in which motion artifacts are substantially suppressed in large scale objects, but motion artifacts are not substantially suppressed in small objects appearing in the image.
Claim 2
Dependent Claim
80 words
In a method for correcting an NMR data set to suppress image artifacts caused by motion, the improvement comprising: applying the corrective method only to views in a selected central region of the NMR data set; and reconstructing an image from the selectively corrected NMR data set using a Fourier transformation to produce an image in which motion artifacts are substantially suppressed in large scale objects, but motion artifacts are not substantially suppressed in small objects appearing in the image.
Claim 3
Independent Claim
65 words
A method for producing an NMR image, the steps comprising: acquiring NMR data for the peripheral regions of an NMR data set using a first NMR pulse sequence; acquiring NMR data for the central region of the NMR data set using a second pulse sequence which employs motion artifact suppression gradient pulses; and reconstructing an image from the NMR data set using a Fourier transformation.
Claim 4
Independent Claim
65 words
A method for producing an NMR image, the steps comprising: acquiring NMR data for the peripheral regions of an NMR data set using a first NMR pulse sequence; acquiring NMR data for the central region of the NMR data set using a second pulse sequence which employs motion artifact suppression gradient pulses; and reconstructing an image from the NMR data set using a Fourier transformation.
Claim 5
Dependent Claim
24 words
The method as recited in claim 2 in which the second pulse sequence employs gradient moment nulling to rephase signals produced by moving spins.
Claim 6
Dependent Claim
37 words
The method as recited in claim 2 in which the central region of the NMR data set is comprised of more than 2 views of acquired NMR data and less than 10 views of acquired NMR data.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |