Patent CH169181A successfully refreshed from Google Patents.
Patent BE496247A successfully refreshed from Google Patents.
US5570019A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for magnetic resonance spectroscopic imaging with multiple spin-echoes
Assignee: United States Department of Health and Human Services
•
Filing: 1995-10-03
•
Granted: 1996-10-29
•
Expires: 2015-10-03
Abstract
Abstract A nuclear magnetic resonance pulse sequence to provide spectral encoding so that the resulting series of spin-echoes each include both spatial and spectral information for spectroscopic imaging. Atoms within the object are excited and may then be spatially encoded, as by a phase encoding gradient. A series of refocusing pulses is then applied, inducing a respective series of spin-echoes. Spectral information is directly encoded in the spin-echo signals. The multiple spin-echoes may be used for sampling different points of k-space, and/or for increasing the signal-to-noise ratio by averaging. In an alternative embodiment, the present invention produces compound weighted spectroscopic images by selecting the period between refocussing pulses according to the coupling constant of a group contained in the compound; thereby, the signal of the selected compounds modulate with a known frequency different for compounds with different coupling constants.
Inventors
- 👤 Chrit T. W. Moonen
- 👤 Jeff Duyn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:45
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/561; G01R33/5615; G01R33/483; G01R33/4833; G01R33/485; G01R33/5617
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
110 words
A method for acquiring nuclear magnetic resonance information, comprising the steps of: exciting at least some of the atoms of an object; providing a plurality of refocusing pulses, each for generating a respective spin echo signal from a common region of the object, successive refocussing pulses separated by a respective refocussing repetition time period, and each of said refocussing pulses associated with a respective phase encoding gradient for individually phase encoding each of the respective spin echo signals to provide spatial information; and receiving, in the absence of an externally applied magnetic field gradient, the respective spin echo signals from the object after at least one of the refocusing pulses.
Claim 2
Independent Claim
110 words
A method for acquiring nuclear magnetic resonance information, comprising the steps of: exciting at least some of the atoms of an object; providing a plurality of refocusing pulses, each for generating a respective spin echo signal from a common region of the object, successive refocussing pulses separated by a respective refocussing repetition time period, and each of said refocussing pulses associated with a respective phase encoding gradient for individually phase encoding each of the respective spin echo signals to provide spatial information; and receiving, in the absence of an externally applied magnetic field gradient, the respective spin echo signals from the object after at least one of the refocusing pulses.
Claim 3
Dependent Claim
27 words
The method according to claim 1, wherein exciting the atoms comprises exciting the atoms of the object by applying at least one excitation pulse to the object.
Claim 4
Dependent Claim
17 words
The method according to claim 1, wherein said spin echo signals are directly encoded with spectral information.
Claim 5
Dependent Claim
38 words
The method according to claim 1, exciting the atoms further comprising applying a slice selecting magnetic gradient field to the object while applying the excitation pulse, said slice selecting magnetic gradient field being applied in a first direction.
Claim 6
Dependent Claim
41 words
The method according to claim 1, further comprising, before receiving said respective spin echo signals, applying a phase encoding magnetic gradient field in a second direction orthogonal to the first direction for spatially encoding the excited atoms in said second direction.
Claim 7
Dependent Claim
48 words
The method according to claim 5, further comprising, before receiving said respective spin echo signals, applying a phase encoding magnetic gradient field in a third direction orthogonal to the first direction for spatially encoding the excited atoms in the plane containing said second direction and said third direction.
Claim 8
Dependent Claim
37 words
The method according to claim 1, wherein the step of exciting the atoms comprises applying a plurality of excitation pluses to the object; and wherein a plurality of the refocusing pluses are provided after each excitation pulse.
Claim 9
Dependent Claim
21 words
The method according to claim 1, wherein said refocussing repetition period is varied depending on the field homogeneity of said object.
Claim 10
Dependent Claim
35 words
The method according to claim 1, wherein said refocussing repetition period is varied depending of the coupling constant of a group contained in a component of said object, thereby modulating the phase of said spin-echo.
Claim 11
Independent Claim
99 words
A method of acquiring spectroscopic magnetic resonance imaging information for an object, comprising the steps of: exciting some of the atoms in the object; providing a plurality of refocussing pulses for stimulating a respective plurality of spin echo signals from a common region of the object; selectively generating a plurality of phase encoding gradients in at least two directions for spatially encoding said plurality of spin echo signals to provide spatial information; and receiving, in the absence of an externally applied magnetic field gradient, said spin echo signals, wherein spectroscopic information is directly encoded in said spin echo signal.
Claim 12
Independent Claim
99 words
A method of acquiring spectroscopic magnetic resonance imaging information for an object, comprising the steps of: exciting some of the atoms in the object; providing a plurality of refocussing pulses for stimulating a respective plurality of spin echo signals from a common region of the object; selectively generating a plurality of phase encoding gradients in at least two directions for spatially encoding said plurality of spin echo signals to provide spatial information; and receiving, in the absence of an externally applied magnetic field gradient, said spin echo signals, wherein spectroscopic information is directly encoded in said spin echo signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-10-29 | 2000-04-29 | 2000-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-29 | 2004-04-29 | 2004-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-29 | 2008-04-29 | 2008-10-29 | $7700.00 | Window Closed / Lapsed |