US4863715A
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Method of NMK imaging using a contrast agent comprising particles of a ferromagnetic material
Assignee: GE Healthcare AS
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Filing: 1985-03-28
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Granted: 1989-09-05
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Expires: 2005-03-28
Abstract
Abstract Ferromagnetic particles, conveniently embedded in or coated by a biotolerable polymer and held in dispersion in a physiologically acceptable dispersion medium, may be used as contrast agents in nmr imaging for the production of images suitable for use in diagnosis. Unlike paramagnetic nmr contrast agents, ferromagnetic nmr contrast agents give particularly good contrast in the T 2 dependent images.
Inventors
- 👤 Trond Jacobsen
- 👤 Jo Klaveness
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:06
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/5601; A; A61; A61K; A61K49/00; A61K49/06; A61K49/18; A61K49/1806; A61K49/1818; Y; Y10; Y10S; Y10S436/00; Y10S436/806; Y10T; Y10T436/00; Y10T436/24
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
66 words
In a method of NMR imaging of a sample which comprises introducing a contrast agent into the sample and generating an image of the sample, wherein the improvement comprises introducing into the sample a contrast agent comprising a plurality of particles of a ferromagnetic material of about 0.6 micrometer or less in size and generating as the image of the sample a T 2 -dependent image.
Claim 2
Dependent Claim
66 words
In a method of NMR imaging of a sample which comprises introducing a contrast agent into the sample and generating an image of the sample, wherein the improvement comprises introducing into the sample a contrast agent comprising a plurality of particles of a ferromagnetic material of about 0.6 micrometer or less in size and generating as the image of the sample a T 2 -dependent image.
Claim 3
Dependent Claim
45 words
A method as claimed in claim 1 of nmr imaging of a human or non-human animal body to produce an nmr image suitable for use in diagnosis wherein said contrast agent is introduced into the region of said body of which said image is generated.
Claim 4
Dependent Claim
17 words
A method as claimed in claim 2 wherein said contrast agent is administered to said body parenterally.
Claim 5
Dependent Claim
22 words
A method as claimed in claim 3 wherein said image is an image of tissue for which said contrast agent is tissue-specific.
Claim 6
Dependent Claim
16 words
A method as claimed in claim 4 wherein said image is of the liver or spleen.
Claim 7
Dependent Claim
26 words
A method as claimed in claim 2 wherein said contrast agent is in the form of a dispersion of particles in a physiologically acceptable dispersion medium.
Claim 8
Dependent Claim
30 words
A method as claimed in claim 6 wherein said contrast agent is introduced into the bladder, uterus, biliary duct or parotid duct or into the digestive tract of said body.
Claim 9
Dependent Claim
29 words
A method as claimed in claim 7 wherein said particles of ferromagnetic material are embedded in or coated with a non-ferromagnetic matrix or coating of a non-biodegradable, biotolerable polymer.
Claim 10
Dependent Claim
36 words
A method as claimed in claim 8 wherein said coated or matrix-embedded particles have a maximum dimension in the range 0.1 to 20 μm and have a ferromagnetic content of from 0.5 to 50% by weight.
Claim 11
Dependent Claim
26 words
A method as claimed in claim 9 wherein said coated or matrix-embedded particles have a maximum dimension in the range of from 5 to 20 um.
Claim 12
Dependent Claim
19 words
A method as claimed in claim 7 wherein said contrast agent comprises a viscosity enhancing agent and/or a surfactant.
Claim 13
Dependent Claim
17 words
A method as claimed in claim 1 wherein said T 2 dependent image is T 2 image.
Claim 14
Dependent Claim
14 words
A method as claimed in claim 12 wherein said image is a spin-echo image.
Claim 15
Dependent Claim
20 words
A method as claimed in claim 1 wherein said contrast agent comprises particles of at least 0.002 micrometer in size.
Claim 16
Dependent Claim
20 words
A method as claimed in claim 1 wherein said contrast agent comprises particles of at least 0.002 micrometer in size.
Claim 17
Dependent Claim
18 words
A method as claimed in claim 1 wherein said contrast agent comprises uncoated particles of a ferromagnetic material.
Claim 18
Dependent Claim
16 words
A method as claimed in claim 1 wherein said ferromagnetic material is a magnetic iron oxide.
Claim 19
Dependent Claim
14 words
A method as claimed in claim 17 wherein said ferromagnetic material is a ferrite.
Claim 20
Dependent Claim
19 words
A method as claimed in claim 17 wherein said ferromagnetic material is magnetite or γ-Fe 2 O 3 .
Claim 21
Dependent Claim
63 words
In a method of NMR imaging of a sample which comprises introducing a contrast agent into the sample and generating an image of the sample, wherein the improvement comprises introducing into the sample a contrast agent comprising a plurality of ferrite particles of about 0.6 micrometer or less in size and generating as the image of the sample a T 2 -dependent image.
Claim 22
Dependent Claim
63 words
In a method of NMR imaging of a sample which comprises introducing a contrast agent into the sample and generating an image of the sample, wherein the improvement comprises introducing into the sample a contrast agent comprising a plurality of ferrite particles of about 0.6 micrometer or less in size and generating as the image of the sample a T 2 -dependent image.
Claim 23
Dependent Claim
20 words
A method as claimed in claim 20 wherein said ferrite particles are of about 0.02 micrometer or less in size.
Claim 24
Dependent Claim
20 words
A method as claimed in claim 21 wherein said ferrite particles are uncoated or are embedded in a non-ferromagnetic matrix.
Claim 25
Dependent Claim
20 words
A method as claimed in claim 20 wherein said ferrite particles are uncoated or are embedded in a non-ferromagnetic matrix.
Claim 26
Dependent Claim
14 words
A method as claimed in claim 20 wherein said image is a spin-echo image.
Claim 27
Dependent Claim
55 words
In a method of NMR imaging of a sample which comprises introducing a contrast agent into said sample and generating an imaging of said sample, wherein the improvement comprises introducing into said sample a contrast agent comprising a plurality of superparamagnetic particles and generating as said image of said sample a T 2 -dependent image.
Claim 28
Dependent Claim
55 words
In a method of NMR imaging of a sample which comprises introducing a contrast agent into said sample and generating an imaging of said sample, wherein the improvement comprises introducing into said sample a contrast agent comprising a plurality of superparamagnetic particles and generating as said image of said sample a T 2 -dependent image.
Claim 29
Dependent Claim
46 words
A method as claimed in claim 25 of NMR imaging of a human or a non-human animal body to produce an NMR image suitable for use in diagnosis wherein said contrast agent is introduced into the region of said body of which said image is generated.
Claim 30
Dependent Claim
26 words
A method as claimed in claim 26 wherein said contrast agent is in the form of a dispersion of particles in a physiologically acceptable dispersion medium.
Claim 31
Dependent Claim
30 words
A method as claimed in claim 27 wherein said contrast agent is introduced into the bladder, uterus, biliary duct or parotid duct or into the digestive tract of said body.
Claim 32
Dependent Claim
27 words
A method as claimed in claim 28 wherein said superparamagnetic particles are embedded in or coated with a non-ferromagnetic matrix or coating of a non-biodegradeable, biotorable polymer.
Claim 33
Dependent Claim
23 words
A methodaas claimed in claim 29 wherein said coated or matrix-embedded particles have a maximum dimension in the range 0.1 to 20 micrometers.
Claim 34
Dependent Claim
19 words
A method as claimed in claim 28 wherein said contrast agent comprises a viscosity enhancing agent and/or a surfactant.
Claim 35
Dependent Claim
16 words
A method as claimed in claim 25 wherein said image is a T 2 -dependent image.
Claim 36
Dependent Claim
18 words
A method as claimed in claim 32 wherein said T 2 dependent image is a T 2 image.
Claim 37
Dependent Claim
14 words
A method as claimed in claim 33 wherein said image is a spin-echo image.
Claim 38
Dependent Claim
73 words
In a method of NMR imaging of a sample which comprises introducing a contrast agent into said sample and generating an image of the sample, wherein the improvement comprises introducing into said sample a contrast agent comprising a plurality of particles of a biotolerable polymeric matrix carrying particles of a ferromagnetic material of about 0.6 micrometer or less in size and generating as said image of said sample a T 2 -dependent image.
Claim 39
Dependent Claim
73 words
In a method of NMR imaging of a sample which comprises introducing a contrast agent into said sample and generating an image of the sample, wherein the improvement comprises introducing into said sample a contrast agent comprising a plurality of particles of a biotolerable polymeric matrix carrying particles of a ferromagnetic material of about 0.6 micrometer or less in size and generating as said image of said sample a T 2 -dependent image.
Claim 40
Dependent Claim
61 words
In a method of NMR imaging of a sample which comprises introducing a contrast agent into said sample and generating an image of said sample, wherein the comprises introducing into said sample a contrast agent comprising a plurality of particles of a biotolerable polymeric matrix carrying superparamagnetic particles and generating as said image of said sample a T 2 -dependent image.
Claim 41
Dependent Claim
61 words
In a method of NMR imaging of a sample which comprises introducing a contrast agent into said sample and generating an image of said sample, wherein the comprises introducing into said sample a contrast agent comprising a plurality of particles of a biotolerable polymeric matrix carrying superparamagnetic particles and generating as said image of said sample a T 2 -dependent image.
References Cited (Backward Citations)
GB1174366A
Cited
GB1339537A
Cited
WO1978000005A1
Cited
US4247406A
Cited
US4331654A
Cited
WO1983001738A1
Cited
WO1983003426A1
Cited
WO1983003920A1
Cited
WO1984002643A1
Cited
US4731239A
Cited
US4675173A
Cited
US4770183A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-04 | 1993-03-06 | 1993-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-04 | 1997-03-06 | 1997-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-04 | 2001-03-06 | 2001-09-05 | $7700.00 | Window Closed / Lapsed |