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US6486670B2
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Method for imaging with nuclear magnetic resonance given a k-space trajectory proceeding on an irregular grid
Assignee: Siemens AG
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Filing: 2001-04-02
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Granted: 2002-11-26
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Expires: 2021-04-02
Abstract
Abstract In a method for imaging with nuclear magnetic resonance, magnetic resonance signals are read out under the influence of a magnetic gradient field. A direction of a gradient of the gradient field is modified such during the reception. The k-space trajectory proceeds along a curved path. The magnetic resonance signals are sampled with a variable sampling rate and are digitized. The sampling rate is varied such that an occupation density of k-space with samples is essentially uniform. Interpolation samples that are arranged on a rectangular grid in k-space are generated from the samples by interpolation. The interpolation samples are subjected to a Fourier transformation for generating image data.
Inventors
- 👤 Oliver Heid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:03
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/4818; G01R33/4824; G01R33/54; G01R33/56; G01R33/565; G01R33/56509
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
145 words
A method for producing an image with nuclear magnetic resonance comprising the steps of: obtaining magnetic resonance signals while a magnetic gradient field is activated, said magnetic gradient field having a gradient with a direction; modifying the direction of the gradient of the gradient field while obtaining said magnetic resonance signals, thereby producing a curved k-space trajectory; sampling said magnetic resonance signals with a variable sampling rate to obtain samples, and digitizing said samples; entering said samples into k-space along said curved k-space trajectory and varying said sampling rate so that an occupation density of k-space with said samples is substantially uniform; producing samples on a rectangular grid in k-space by interpolating the samples entered into k-space along said curved k-space trajectory; Fourier transforming said samples on said rectangular grid in k-space to generate image data; and generating a displayable image from said image data.
Claim 2
Independent Claim
145 words
A method for producing an image with nuclear magnetic resonance comprising the steps of: obtaining magnetic resonance signals while a magnetic gradient field is activated, said magnetic gradient field having a gradient with a direction; modifying the direction of the gradient of the gradient field while obtaining said magnetic resonance signals, thereby producing a curved k-space trajectory; sampling said magnetic resonance signals with a variable sampling rate to obtain samples, and digitizing said samples; entering said samples into k-space along said curved k-space trajectory and varying said sampling rate so that an occupation density of k-space with said samples is substantially uniform; producing samples on a rectangular grid in k-space by interpolating the samples entered into k-space along said curved k-space trajectory; Fourier transforming said samples on said rectangular grid in k-space to generate image data; and generating a displayable image from said image data.
Claim 3
Dependent Claim
34 words
A method as claimed in claim 1 , wherein the step of modifying said direction of said gradient on said gradient field comprises continuously modifying said direction of said gradient of said magnetic field.
Claim 4
Dependent Claim
25 words
A method as claimed in claim 2 , comprising entering said samples into k-space along a spirally proceeding k-space trajectory as said curved k-space trajectory.
Claim 5
Dependent Claim
28 words
A method as claimed in claim 3 , comprising entering said samples into k-space along a trajectory proceeding according to an Archimedean spiral as said curved k-space trajectory.
Claim 6
Dependent Claim
33 words
A method as claimed in claim 1 , comprising interpolating said samples entered into k-space along said curved k-space trajectory with a sinc interpolation to produce said samples arranged on a rectangular grid.
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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) | 2005-11-25 | 2006-05-27 | 2006-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-11-25 | 2010-05-27 | 2010-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-11-25 | 2014-05-27 | 2014-11-26 | $7700.00 | Window Closed / Lapsed |