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US4727326A
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US
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Method and device for forming images by nuclear magnetic resonance
Assignee: THOMSON-CGR 13 SQUARE MAX HYMANS 75015 PARIS FRANCE
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Filing: 1986-03-24
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Granted: 1988-02-23
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Expires: 2006-03-24
Abstract
Abstract The invention provides a method and device for forming images by nuclear magnetic resonance in which an image is constructed by discrimination of the intrinsic parameters of the tissues examined. The image is formed by putting forward the degrees of attachment and mobility of the nuclei of the tissues. The parameters displayed represent the field heterogeneities at the microscopic and molecular levels. The method consists in acquiring a first image using conventional methods then, after slightly varying the orientater magnetic field, in acquiring another image using the same methods. Then an image of another type is formed by representing the relative variations of the relaxation times between this first and this second image.
Inventors
- 👤 Daniel Kaplan
- 👤 Georges Roux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:44
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/50
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
100 words
A method of forming images by nuclear magnetic resonance comprising the steps of: acquiring an image of the volume element of a section of a body to be examined by discrimination of the relaxation times of the nucleii of said volume elements in the presence of a first value of a given orientating magnetic field; reiterating said acquisition step for a second value of said magnetic field; and forming another type of image of said section by representing for each image element the relative variations of the relaxation times between said step of acquiring and said reiterated step of acquiring.
Claim 2
Independent Claim
100 words
A method of forming images by nuclear magnetic resonance comprising the steps of: acquiring an image of the volume element of a section of a body to be examined by discrimination of the relaxation times of the nucleii of said volume elements in the presence of a first value of a given orientating magnetic field; reiterating said acquisition step for a second value of said magnetic field; and forming another type of image of said section by representing for each image element the relative variations of the relaxation times between said step of acquiring and said reiterated step of acquiring.
Claim 3
Dependent Claim
51 words
The method as claimed in claim 1, wherein said acquisitions are reiterated a certain number of times, each time for different values of the fields and the image of the section is formed by representing the relative variations of the relaxation times by effecting a statistical estimation of the relative variations.
Claim 4
Dependent Claim
17 words
The method as claimed in claim 2, wherein the statistical estimation is established with minimum quadratic deviation.
Claim 5
Independent Claim
145 words
A device for forming images by nuclear magnetic resonance of the type comprising means for subjecting a body to be examined to an orientating magnetic field, field gradient means for determining a section of the body, means for producing a pulsed alternating magnetic field for exciting the nucleii of the volume elements of the section, means for measuring the relaxation times of these nuclei after excitation, and means for acquiring an image of the section by representing these relaxation times, which device further comprises means for storing the image, means for varying the orientating magnetic field and the frequency of the pulsed magnetic field so as to acquire, using the same procedure, another image of the same section, and means for forming an image of this section, of another type, by representing the relative variations of the relaxation times between the first and second acquisitions.
Claim 6
Independent Claim
145 words
A device for forming images by nuclear magnetic resonance of the type comprising means for subjecting a body to be examined to an orientating magnetic field, field gradient means for determining a section of the body, means for producing a pulsed alternating magnetic field for exciting the nucleii of the volume elements of the section, means for measuring the relaxation times of these nuclei after excitation, and means for acquiring an image of the section by representing these relaxation times, which device further comprises means for storing the image, means for varying the orientating magnetic field and the frequency of the pulsed magnetic field so as to acquire, using the same procedure, another image of the same section, and means for forming an image of this section, of another type, by representing the relative variations of the relaxation times between the first and second acquisitions.
Claim 7
Dependent Claim
47 words
The device as claimed in claim 4, further comprising means for reiterating the acquisitions a certain number of times, each time for different values of the field, and further comprising means for effecting a statistical estimation of the relative variations of the relaxation times to be represented.
Claim 8
Dependent Claim
35 words
The device as claimed in claim 4, or claim 5, wherein the means for subjecting a body to an orientating magnetic field comprises so called Bitter coils through which a pilot controlled electric current flows.
References Cited (Backward Citations)
GB2056088A
Cited
DE3125502A1
Cited
GB2113399A
Cited
US4607223A
Cited
EP0117042A2
Cited
US4620154A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-22 | 1991-08-24 | 1992-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-22 | 1995-08-24 | 1996-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-22 | 1999-08-24 | 2000-02-23 | $7700.00 | Window Closed / Lapsed |