US5084818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for Fourier transforming 3 dimensional MR data in predetermined position of interest by using phase-correction in MRI
Assignee: Toshiba Corp
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Filing: 1989-06-05
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Granted: 1992-01-28
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Expires: 2009-06-05
Abstract
Abstract In an MRI system, a region including a portion of interest is selectively excited in a predetermined pulse sequence to acquire 3 dimensional MR data. When the portion of interest is shifted from the center position of imaging, i.e., the center position of a gradient field, the 3 dimensional MR data is phase-corrected in accordance with the shift. The phase-corrected 3 dimensional MR data is 3-dimensional Fourier-transformed to obtain an MR image of a predetermined slice portion.
Inventors
- 👤 Yoshio Machida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:06
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/483; G01R33/4833; G01R33/4818; G01R33/482; G01R33/4822
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
114 words
A method for imaging 3 dimensional magnetic resonance (MR) data in a portion of interest of a subject by using phase-correction in a magnetic resonance imaging (MRI) apparatus, the method comprising the steps of: applying magnetic gradient fields to the subject; acquiring the 3 dimensional MR data by selectively exciting a region including the portion of interest of the subject in accordance with a predetermined pulse sequence; determining the distance between the portion of interest and a center position of a select one of said gradient fields; phase-correcting the acquired 3 dimensional MR data in accordance with the distance; and Fourier-transforming the phase-corrected 3 dimensional MR data, thereby reconstructing a 3 dimensional MR image.
Claim 2
Independent Claim
114 words
A method for imaging 3 dimensional magnetic resonance (MR) data in a portion of interest of a subject by using phase-correction in a magnetic resonance imaging (MRI) apparatus, the method comprising the steps of: applying magnetic gradient fields to the subject; acquiring the 3 dimensional MR data by selectively exciting a region including the portion of interest of the subject in accordance with a predetermined pulse sequence; determining the distance between the portion of interest and a center position of a select one of said gradient fields; phase-correcting the acquired 3 dimensional MR data in accordance with the distance; and Fourier-transforming the phase-corrected 3 dimensional MR data, thereby reconstructing a 3 dimensional MR image.
Claim 3
Dependent Claim
59 words
The method according to claim 1, wherein the acquired 3 dimensional MR data F(x,y,z) is phase-corrected by the following equation: F(x,y,z)=exp(-iaz) F(x,y,z) a=2πzo/Z where F(x,y,z) is the phase-corrected 3 dimensional MR data, zo is the distance between the center position of the select gradient field and the portion of interest, and Z is a band corresponding to the region.
Claim 4
Independent Claim
132 words
A system For imaging 3 dimensional magnetic resonance (MR) data in a portion of interest of a subject by using phase-correction in a magnetic resonance (MRI) apparatus, the system comprising: acquiring means for acquiring the 3 dimensional MR data by selectively exciting a region including the portion of interest in accordance with applied magnetic gradient fields and a predetermined pulse sequence; determining means for determining the distance between the portion of interest and a center position of a select one of said gradient fields; correcting means for phase-correcting the 3 dimensional MR data in accordance with the set distance; and correcting means for phase-correcting the 3 dimensional MR data in accordance with the set distance; and transforming means for Fourier-transforming the phase-corrected 3 dimensional MR data, thereby reconstructing a 3-dimensional MR image.
Claim 5
Independent Claim
132 words
A system For imaging 3 dimensional magnetic resonance (MR) data in a portion of interest of a subject by using phase-correction in a magnetic resonance (MRI) apparatus, the system comprising: acquiring means for acquiring the 3 dimensional MR data by selectively exciting a region including the portion of interest in accordance with applied magnetic gradient fields and a predetermined pulse sequence; determining means for determining the distance between the portion of interest and a center position of a select one of said gradient fields; correcting means for phase-correcting the 3 dimensional MR data in accordance with the set distance; and correcting means for phase-correcting the 3 dimensional MR data in accordance with the set distance; and transforming means for Fourier-transforming the phase-corrected 3 dimensional MR data, thereby reconstructing a 3-dimensional MR image.
Claim 6
Dependent Claim
60 words
The system according to claim 3, wherein the acquired 3 dimensional MR data F(x,y,z) is phase-corrected by the following equation: F(x,y,z)=exp(-iaz) F(x,y,z) a=2πzo/Z where F(x,y,z) is the phase-corrected 3 dimensional MR data, zo is the distance between the center position of the select gradient field and the portion of interest, and Z is a band corresponding to the excited region.
Claim 7
Dependent Claim
84 words
The system according to claim 3, wherein the acquiring means includes: first generating means for generating a static field; second generating means for generating the gradient fields; applying and receiving means for applying a radio frequency pulse to a subject to be selectively excited and receiving an MR signal from the subject to obtain the 3 dimensional MR data; and control means for controlling the first named and second generating means and the applying and receiving means in accordance with the predetermined pulse sequence.
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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) | 1995-01-27 | 1995-07-29 | 1996-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-27 | 1999-07-29 | 2000-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-27 | 2003-07-29 | 2004-01-28 | $7700.00 | Window Closed / Lapsed |