US5005578A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three-dimensional magnetic resonance image distortion correction method and system
Assignee: SAM TECHNOLOGY Inc 51 FEDERAL STREET SAN FRANCISCO CA 94107 A CORP OF CA
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Filing: 1989-03-28
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Granted: 1991-04-09
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Expires: 2009-03-28
Abstract
Abstract A method and system in Nuclear Magnetic Resonance (NMR) medical imaging systems corrects for three-dimensional distortions arising from the apparatus and patient specific distortions using a phantom and a helmet, both of which have fiducial markers in a three-dimensional matrix. The positions of the phantom and helmet fiducial markers are automatically detected and compared in a computer system which uses image transform algorithms to correct for the various distortions.
Inventors
- 👤 Douglas S. Greer
- 👤 Alan S. Gevins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:11
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/58; G01R33/54; G01R33/56; G01R33/565; A; A61; A61B; A61B90/00; A61B90/36; A61B2090/363; G01R33/56536; G01R33/56563; G06; G06F; G06F2218/00; G06F2218/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
167 words
A method in nuclear magnetic resonance (NMR) for the correction of distortions in an NMR scanner, including the steps of: (a) positioning a plurality of fiducial markers at selected locations on a helmet, said markers providing a readily determined distinctive image in an NMR scan; (b) placing a phantom having a plurality of predetermined fiducial markers at selected locations therein in said NMR device and taking a scan of said phantom; and then removing said phantom from said device after taking the scan; (c) placing the helmet on a subject within the NMR device and taking a scan of the helmeted subject; (d) comparing the locations of the fiducial markers in the scans of the phantom and the helmeted subject by an automatic comparison using a computer system and pattern recognition algorithms; (e) computing in the computer system a first set of distortion corrections providing three-dimensional corrections for the NMR scanner; and (f) applying said three-dimensional corrections to the NMR scanner to produce corrected NMR scan images.
Claim 2
Independent Claim
167 words
A method in nuclear magnetic resonance (NMR) for the correction of distortions in an NMR scanner, including the steps of: (a) positioning a plurality of fiducial markers at selected locations on a helmet, said markers providing a readily determined distinctive image in an NMR scan; (b) placing a phantom having a plurality of predetermined fiducial markers at selected locations therein in said NMR device and taking a scan of said phantom; and then removing said phantom from said device after taking the scan; (c) placing the helmet on a subject within the NMR device and taking a scan of the helmeted subject; (d) comparing the locations of the fiducial markers in the scans of the phantom and the helmeted subject by an automatic comparison using a computer system and pattern recognition algorithms; (e) computing in the computer system a first set of distortion corrections providing three-dimensional corrections for the NMR scanner; and (f) applying said three-dimensional corrections to the NMR scanner to produce corrected NMR scan images.
Claim 3
Dependent Claim
45 words
A method as in claim 1 and including an additional step, to correct for human subject dependent distortions, of computing in the computer system a second set of distortion corrections by using the first set of distortion corrections and a three-dimensional orthogonal planes relaxation algorithm.
Claim 4
Dependent Claim
31 words
A method as in claim 1 and including the additional step of: computing an additional set of distortion corrections, to correct for human subject dependant distortions, using an orthogonal alignment algorithm.
Claim 5
Dependent Claim
81 words
An NMR phantom adapted to be used to correct distortions in a nuclear magnetic resonance device, said NMR phantom being a helmet having a hollowed-out space having the size and shape of a human head and adapted to receive a human head therein wherein, the helmet comprises a three-dimensional matrix of rows and columns having evenly spaced fiducial markers in each row and column, the markers providing a readily determined image of their location in a scan by a NMR device.
Claim 6
Dependent Claim
81 words
An NMR phantom adapted to be used to correct distortions in a nuclear magnetic resonance device, said NMR phantom being a helmet having a hollowed-out space having the size and shape of a human head and adapted to receive a human head therein wherein, the helmet comprises a three-dimensional matrix of rows and columns having evenly spaced fiducial markers in each row and column, the markers providing a readily determined image of their location in a scan by a NMR device.
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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) | 1994-04-08 | 1994-10-08 | 1995-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-08 | 1998-10-08 | 1999-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-08 | 2002-10-08 | 2003-04-09 | $7700.00 | Window Closed / Lapsed |