US5117187A
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Localized multi-region magnetic resonance data acquisition
Assignee: GE Medical Systems Israel Ltd
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Filing: 1990-06-26
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Granted: 1992-05-26
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Expires: 2010-06-26
Abstract
Abstract A multi-slice magnetic resonance (MR) acquisition sequence for acquiring data from a section of interest wherein the sections surrounding the section of interest are presaturated, then multiple slices from the section of interest are selected and data is acquired from the selected multiple slices.
Inventors
- 👤 Joseph Granot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:38
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/483; G01R33/4833; G01R33/4835
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
168 words
A method of acquiring multi-slices in a volume of interest (VOI) during a magnetic resonance (MR) examination, said method comprising the steps of: determing a VOI in a patient that is a subject of an MR examination, subjecting the patient to a strong static magnetic field, presaturating volumes surrounding the VOI leaving only the VOI unsaturated, said step of presaturating volumes surrounding the VOI comprising the steps of: applying a pair of RF pulses during the application of a first gradient pulse to saturate volumes juxtaposed to both sides of the said VOI, and applying a second pair of RF pulses during the application of a second gradient pulse to saturate volume juxtaposed to the top and bottom of said VOI, selecting multiple slices from the VOI, applying radio frequency (RF) pulses to generate free induction decay (FID) signals in the selected multiple slices, applying gradient pulses to locate the source of the FID signals, and processing the FID signals to provide usable data from the MR examination.
Claim 2
Independent Claim
168 words
A method of acquiring multi-slices in a volume of interest (VOI) during a magnetic resonance (MR) examination, said method comprising the steps of: determing a VOI in a patient that is a subject of an MR examination, subjecting the patient to a strong static magnetic field, presaturating volumes surrounding the VOI leaving only the VOI unsaturated, said step of presaturating volumes surrounding the VOI comprising the steps of: applying a pair of RF pulses during the application of a first gradient pulse to saturate volumes juxtaposed to both sides of the said VOI, and applying a second pair of RF pulses during the application of a second gradient pulse to saturate volume juxtaposed to the top and bottom of said VOI, selecting multiple slices from the VOI, applying radio frequency (RF) pulses to generate free induction decay (FID) signals in the selected multiple slices, applying gradient pulses to locate the source of the FID signals, and processing the FID signals to provide usable data from the MR examination.
Claim 3
Independent Claim
173 words
A method for acquiring multi-slices in a volume of interest (VOI) during a magnetic resonance (MR) examination, said method comprising the steps of: determining a VOI in a patient that is the subject of an MR examination, subjecting the patient to a strong static magnetic field, presaturating volumes surrounding the VOI leaving only the VOI unsaturated, selecting multiple slices from the VOI, the step of selecting multiple slices including the steps of: applying a basic data acquisition scan sequence to obtain data from a selected one of said multiple slices, said basic data acquisitions scan sequence including applying of an RF pulse in the presence of a slice-selecting gradient pulse, said slice-selecting gradient pulse in cooperation with said RF pulse having parameters for selecting and acquiring data from a first slice in said patient, waiting a definite period before reapplying said basic sequence, and reapplying the basic scan sequence during the definite period with pulses of different parameters for selecting and acquiring data from other slices in said patient during said definite period.
Claim 4
Independent Claim
173 words
A method for acquiring multi-slices in a volume of interest (VOI) during a magnetic resonance (MR) examination, said method comprising the steps of: determining a VOI in a patient that is the subject of an MR examination, subjecting the patient to a strong static magnetic field, presaturating volumes surrounding the VOI leaving only the VOI unsaturated, selecting multiple slices from the VOI, the step of selecting multiple slices including the steps of: applying a basic data acquisition scan sequence to obtain data from a selected one of said multiple slices, said basic data acquisitions scan sequence including applying of an RF pulse in the presence of a slice-selecting gradient pulse, said slice-selecting gradient pulse in cooperation with said RF pulse having parameters for selecting and acquiring data from a first slice in said patient, waiting a definite period before reapplying said basic sequence, and reapplying the basic scan sequence during the definite period with pulses of different parameters for selecting and acquiring data from other slices in said patient during said definite period.
Claim 5
Independent Claim
232 words
A system for acquiring multi-slices in a volume of interest (VOI) during a magnetic resonance (MR) examination, said system comprising: means for determining a VOI in a patient that is the subject of an MR examination, means for subjecting the patient to a strong static magnetic field, means for presaturating volumes surrounding the VOI leaving only the VOI unsaturated, means for selecting multiple slices from the VOI, said means for selecting multiple slices including: means for applying a basic data acquisition scan sequence to obtain data from a selected one of said multiple slices, said means for applying a basic data acquisition scan sequence including means for applying an RF pulse in the presence, of a slice-selecting gradient pulse, said slice-selecting gradient pulse in cooperation with said RF pulse having parameters for selecting and acquiring data from a first slice in said patient, means for waiting a definite period before reapplying said basic sequence, and means for reapplying the basic sequence during the definite period with pulses of different parameters for selecting and acquiring data from other slices in said patient during said definite period, means for applying radio frequency (RF) pulses to generate free induction decay (FID) signals in the selected multiple slices, means for applying gradient pulses to locate the source of the FID signals, and means for processing the FID signals to provide usable data from the MR examination.
Claim 6
Independent Claim
232 words
A system for acquiring multi-slices in a volume of interest (VOI) during a magnetic resonance (MR) examination, said system comprising: means for determining a VOI in a patient that is the subject of an MR examination, means for subjecting the patient to a strong static magnetic field, means for presaturating volumes surrounding the VOI leaving only the VOI unsaturated, means for selecting multiple slices from the VOI, said means for selecting multiple slices including: means for applying a basic data acquisition scan sequence to obtain data from a selected one of said multiple slices, said means for applying a basic data acquisition scan sequence including means for applying an RF pulse in the presence, of a slice-selecting gradient pulse, said slice-selecting gradient pulse in cooperation with said RF pulse having parameters for selecting and acquiring data from a first slice in said patient, means for waiting a definite period before reapplying said basic sequence, and means for reapplying the basic sequence during the definite period with pulses of different parameters for selecting and acquiring data from other slices in said patient during said definite period, means for applying radio frequency (RF) pulses to generate free induction decay (FID) signals in the selected multiple slices, means for applying gradient pulses to locate the source of the FID signals, and means for processing the FID signals to provide usable data from the MR examination.
Claim 7
Dependent Claim
40 words
The method of presaturating volumes surrounding the VOI of claim 1 including the steps of applying spoiler gradient pulses between said RF pulses of said first and said second pair of RF pulses to assure that said VOI remains unsaturated.
Claim 8
Dependent Claim
22 words
The method of claim 4 including the step of applying spoiler gradient pulses after the application of each pair of RF pulses.
Claim 9
Dependent Claim
16 words
The method of claim 2 wherein said different parameters include different frequencies for said RF pulses.
Claim 10
Dependent Claim
15 words
The method of claim 2 wherein said different parameters include gradient pulses of different amplitudes.
Claim 11
Dependent Claim
16 words
The method of claim 2 wherein said different parameters include different bandwidths for said RF pulse.
Claim 12
Dependent Claim
77 words
The method of claim 2 including applying multiple RF pulses of different frequencies in the presence of different gradient pulses to select multiple slices in the patient, and applying a plurality of RF pulses of the same frequency during the application of gradient pulses of the same amplitudes to obtain a plurality of signals from each of the slabs selected by the multiple RF pulses, and averaging said plurality of signals to obtain a useable signal-to-noise ratio.
Claim 13
Dependent Claim
21 words
The methods of claim 2 wherein said RF pulses used for saturation purposes are sets of frequency modulated 90° RF pulses.
Claim 14
Dependent Claim
20 words
The method of claim 2 wherein said step of applying a basic scan sequence comprises using a spin echo sequence.
Claim 15
Dependent Claim
11 words
The methods of claim 1 wherein said data is spectroscopic data.
Claim 16
Dependent Claim
21 words
The methods of claim 1 including the step of applying phase encoding gradient pulses after application of the slab selecting pulses.
Claim 17
Independent Claim
182 words
A system of acquiring multi-slices in a volume of interest (VOI) during a magnetic resonance (MR) examination, said system comprising: means for determining a VOI in a patient that is the subject of an MR examination, means for subjecting the patient to a strong static magnetic field, means for presaturating volumes surrounding the VOI leaving only the VOI unsaturated, said means for presaturating the volumes surrounding the volume of interest comprises: means for applying a pair of RF pulses during the application of a first gradient pulse to saturate volumes juxtaposed to both sides of said VOI, and means for applying a second pair of RF pulses during the application of a second gradient pulse to saturate volumes juxtaposed to the top and bottom of said VOI, means for selecting multiple slices from the VOI, means for applying radio frequency (RF) pulses to generate free induction decay (FID) signals in the selected multiple slices, means for applying gradient pulses to locate the source of the FID signals, and means for processing the FID signals to provide usable data from the MR examination.
Claim 18
Independent Claim
182 words
A system of acquiring multi-slices in a volume of interest (VOI) during a magnetic resonance (MR) examination, said system comprising: means for determining a VOI in a patient that is the subject of an MR examination, means for subjecting the patient to a strong static magnetic field, means for presaturating volumes surrounding the VOI leaving only the VOI unsaturated, said means for presaturating the volumes surrounding the volume of interest comprises: means for applying a pair of RF pulses during the application of a first gradient pulse to saturate volumes juxtaposed to both sides of said VOI, and means for applying a second pair of RF pulses during the application of a second gradient pulse to saturate volumes juxtaposed to the top and bottom of said VOI, means for selecting multiple slices from the VOI, means for applying radio frequency (RF) pulses to generate free induction decay (FID) signals in the selected multiple slices, means for applying gradient pulses to locate the source of the FID signals, and means for processing the FID signals to provide usable data from the MR examination.
Claim 19
Dependent Claim
39 words
The system of presaturating volumes surrounding the VOI of claim 14 including means for applying spoiler gradient pulses between said RF pulses of said first and said second pair of RF pulses to assure that said VOI remains unsaturated.
Claim 20
Dependent Claim
21 words
The system of claim 15 including means for applying spoiler gradient pulses after the application of each pair of RF pulses.
Claim 21
Dependent Claim
16 words
The system of claim 3 wherein said different parameters include different frequencies for said RF pulses.
Claim 22
Dependent Claim
15 words
The system of claim 3 wherein said different parameters include gradient pulses of different amplitudes.
Claim 23
Dependent Claim
16 words
The system of claim 3 wherein said different parameters include different bandwidths for said RF pulses.
Claim 24
Dependent Claim
81 words
The method of claim 3 including means for applying multiple RF pulses of different frequencies in the presence of different gradient pulses to select multiple slices in the patient, and means for applying a plurality of RF pulses of the same frequency during the application of gradient pulses of the same amplitudes to obtain a plurality of signals from each of the slabs selected by the multiple RF pulses, and averaging said plurality of signals to obtain a useable signal-to-noise ratio.
Claim 25
Dependent Claim
21 words
The system of claim 3 wherein said RF pulses used for saturation purposes are sets of frequency modulated 90° RF pulses.
Claim 26
Dependent Claim
22 words
The system of claim 3 wherein said means for applying a basic scan sequence comprises means for applying a spin echo sequence.
Claim 27
Dependent Claim
11 words
The system of claim 14 wherein said data is spectroscopic data.
Claim 28
Dependent Claim
24 words
The system of claim 14 including means for applying phase encoding gradient pulses after application of the slice selecting pulses to acquire imaging data.
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) | 1995-05-26 | 1995-11-25 | 1996-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-26 | 1999-11-25 | 2000-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-26 | 2003-11-25 | 2004-05-26 | $7700.00 | Window Closed / Lapsed |