Patent US5912557A successfully refreshed from Google Patents.
US5912557A
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Centric phase encoding order for 3D NMR data acquisition
Assignee: Mayo Clinic in Florida
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Filing: 1997-02-19
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Granted: 1999-06-15
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Expires: 2017-02-19
Abstract
Abstract A 3DFT NMR scan is performed by stepping two phase encoding gradients through a sequence of values to sample all locations in k-space. The gradients are stepped such that k-space is covered by sampling closer to the origin of k-space first. Two methods for ordering the k-space sample points are disclosed.
Inventors
- 👤 Alan H. Wilman
- 👤 Stephen J. Riederer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:14
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/4818; G01R33/482; G01R33/4822
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
194 words
A method for acquiring an NMR data set which is employed to reconstruct an image using a Fourier transformation, the steps comprising: inputting image parameters which define the fields of view of the image along two axes; producing a set of k-space sample points which identify the locations in k-space along said two axes which are to be sampled to produce an image with the defined fields of view; ordering the k-space sample points in a list such that the k-space sample points closer to the origin of k-space are listed first; performing an NMR pulse sequence in an NMR system to acquire sample NMR data for the NMR data set, the NMR pulse sequence including a first phase encoding gradient pulse having a magnitude which determines the location of the sample NMR data along a first of said two axes in k-space, and a second phase encoding gradient pulse having a magnitude which determines the location of the sample NMR data along a second of said two axes in k-space; and repeating the NMR pulse sequence to acquire sample NMR data for the NMR data set in the order indicated by said list.
Claim 2
Independent Claim
194 words
A method for acquiring an NMR data set which is employed to reconstruct an image using a Fourier transformation, the steps comprising: inputting image parameters which define the fields of view of the image along two axes; producing a set of k-space sample points which identify the locations in k-space along said two axes which are to be sampled to produce an image with the defined fields of view; ordering the k-space sample points in a list such that the k-space sample points closer to the origin of k-space are listed first; performing an NMR pulse sequence in an NMR system to acquire sample NMR data for the NMR data set, the NMR pulse sequence including a first phase encoding gradient pulse having a magnitude which determines the location of the sample NMR data along a first of said two axes in k-space, and a second phase encoding gradient pulse having a magnitude which determines the location of the sample NMR data along a second of said two axes in k-space; and repeating the NMR pulse sequence to acquire sample NMR data for the NMR data set in the order indicated by said list.
Claim 3
Dependent Claim
51 words
The method as recited in claim 1 in which the k-space sample points are ordered by: calculating a number for each k-space sample point which indicates the distance from the origin of k-space to the k-space sample point; and sorting the k-space sample points on the basis of their distance numbers.
Claim 4
Dependent Claim
59 words
The method as recited in claim 1 in which the k-space sample points are ordered by; establishing a master array which defines all possible sample points in k-space and assigns a rank to each of said sample points; and sorting the k-space sample points on the basis of the rank of their corresponding sample point in the master array.
References Cited (Backward Citations)
US5122747A
Cited
US5758646A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-06-14 | 2002-12-14 | 2003-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-06-14 | 2006-12-14 | 2007-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-06-14 | 2010-12-14 | 2011-06-15 | $7700.00 | Window Closed / Lapsed |