US4803431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for imaging three-dimensional moving object
Assignee: Hitachi Ltd
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Filing: 1987-07-21
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Granted: 1989-02-07
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Expires: 2007-07-21
Abstract
Abstract A method for imaging a three-dimensional moving object is disclosed, by which a static magnetic field, gradient magnetic fields and high frequency magnetic field are generated; a nuclear magnetic resonance signal due to them coming from an examined object is detected; and various sorts of operations including image reconstruction are effected, starting from the signal thus detected so that the speed of moving object moving in any three-dimensional direction, independently of the slice direction, can be measured by one imaging.
Inventors
- 👤 Koichi Sano
- 👤 Shinichi Sato
- 👤 Tetsuo Yokoyama
- 👤 Hideaki Koizumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:27
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/563; G01R33/56308; G01R33/4818; G01R33/482; G01R33/4822
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
141 words
A single sequence method for imaging a three-dimensional moving object in an examined object located in a predetermined magnetic field comprising the following steps of: (a) generating a high frequency pulse train used for exciting hydrogen spin in the examined object; (b) generating gradient magnetic fields in three orthogonal directions, which are utilized for measuring the speed of the moving object in the examined object; (c) generating a 180° pulse a plurality of times for obtaining echo signals with respect to nuclear magnetic resonance signal produced by said high frequency pulse train; (d) measuring variations in the phase in said three orthogonal directions on the basis of multi-echo signals obtained by said 180° pulses; and (e) obtaining speed components in the phase in said three orthogonal directions of said moving object on the basis of the measured variations in the phase.
Claim 2
Dependent Claim
141 words
A single sequence method for imaging a three-dimensional moving object in an examined object located in a predetermined magnetic field comprising the following steps of: (a) generating a high frequency pulse train used for exciting hydrogen spin in the examined object; (b) generating gradient magnetic fields in three orthogonal directions, which are utilized for measuring the speed of the moving object in the examined object; (c) generating a 180° pulse a plurality of times for obtaining echo signals with respect to nuclear magnetic resonance signal produced by said high frequency pulse train; (d) measuring variations in the phase in said three orthogonal directions on the basis of multi-echo signals obtained by said 180° pulses; and (e) obtaining speed components in the phase in said three orthogonal directions of said moving object on the basis of the measured variations in the phase.
Claim 3
Dependent Claim
24 words
A method for imaging a three-dimensional moving object according to claim 1, further comprising a step of correcting phase distortions of said echo signals.
Claim 4
Independent Claim
162 words
A method for imaging a three-dimensional moving object in an examined object located in a predetermined magnetic field comprising the following steps of: (a) generating a high frequency pulse train used for exciting hydrogen spin in the examined object; (b) generating gradient magnetic fields in three orthogonal directions, which are utilized for measuring the speed of the moving object in the examined object; (c) generating a 180° pulse a plurality of times for obtaining echo signals with respect to nuclear magnetic resonance signal produced by said high frequency pulse train; (d) measuring variations in the phase in one of said three orthogonal directions on the basis of multi-echo signals obtained by said 180° pulse; (e) repeating said steps (b)-(d) a predetermined number of times to measure variations in the phase in the other orthogonal directions; and (f) obtaining speed components in the phase in said three orthogonal directions of said moving object on the basis of the measured variations in the phase.
Claim 5
Independent Claim
162 words
A method for imaging a three-dimensional moving object in an examined object located in a predetermined magnetic field comprising the following steps of: (a) generating a high frequency pulse train used for exciting hydrogen spin in the examined object; (b) generating gradient magnetic fields in three orthogonal directions, which are utilized for measuring the speed of the moving object in the examined object; (c) generating a 180° pulse a plurality of times for obtaining echo signals with respect to nuclear magnetic resonance signal produced by said high frequency pulse train; (d) measuring variations in the phase in one of said three orthogonal directions on the basis of multi-echo signals obtained by said 180° pulse; (e) repeating said steps (b)-(d) a predetermined number of times to measure variations in the phase in the other orthogonal directions; and (f) obtaining speed components in the phase in said three orthogonal directions of said moving object on the basis of the measured variations in the phase.
Claim 6
Dependent Claim
24 words
A method for imaging a three-dimensional moving object according to claim 3, further comprising a step of correcting phase distortions of said echo signals.
References Cited (Backward Citations)
US4602641A
Cited
US4609872A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-07 | 1992-08-08 | 1993-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-07 | 1996-08-08 | 1997-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-07 | 2000-08-08 | 2001-02-07 | $7700.00 | Window Closed / Lapsed |