US5160890A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic resonance examination apparatus using a dielectric resonator
Assignee: US Philips Corp
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Filing: 1991-03-12
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Granted: 1992-11-03
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Expires: 2011-03-12
Abstract
Abstract A dielectric resonator is used in a magnetic resonance examination apparatus comprising a magnet system (31, 32) for generating a steady magnetic field in an examination space (2), a transmitter device (12, 13, 18, 28) for generating an RF field to be superposed on the steady magnetic field in an object (30) to be examined, a device for producing a resonance step-up of the RF field active in the object (30) to be examined, and a device for detecting magnetic resonance signals generated in the object (30) to be examined. Stronger B 1 fields are created by at least one dielectric resonator (1, 5, 10, 16, 17, 20, 21) which neighbors the object (24) to be examined and which comprises a dielectric having a relative dielectric constant ε r >20, the dimensions of the resonator being chosen so that therein, using a neighboring transmitter device, (12, 13, 18) there can be generated at least one resonant mode with a frequency which is in the vicinity of the Larmor frequencies to be detected of the nuclei to be excited in the object (24) to be examined, for example, protons.
Inventors
- 👤 Peter K. H. Roschmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:36
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/30; G01R33/32; G01R33/34; G01R33/36; G01R33/3642
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
158 words
A magnetic resonance examination apparatus, comprising: a magnet system for generating a steady magnetic field in an examination space, a transmitter device for generating an RF field to be superposed on the steady magnetic field in an object to be examined, means for providing a resonance step-up for the RF field strength active in the object to be examined, and a device for detecting magnetic resonance signals generated in the object to be examined, said means for providing including at least one dielectric resonator which neighbors the object to be examined and which comprises a dielectric having a relative dielectric constant ε r >20, the dimensions of the at least one dielectric resonator being chosen so that therein, using a neighboring transmitter device, at least one resonance mode can be excited with a frequency which is in the vicinity of the Larmor frequencies to be detected of the nuclei to be excited in the object to be examined.
Claim 2
Dependent Claim
158 words
A magnetic resonance examination apparatus, comprising: a magnet system for generating a steady magnetic field in an examination space, a transmitter device for generating an RF field to be superposed on the steady magnetic field in an object to be examined, means for providing a resonance step-up for the RF field strength active in the object to be examined, and a device for detecting magnetic resonance signals generated in the object to be examined, said means for providing including at least one dielectric resonator which neighbors the object to be examined and which comprises a dielectric having a relative dielectric constant ε r >20, the dimensions of the at least one dielectric resonator being chosen so that therein, using a neighboring transmitter device, at least one resonance mode can be excited with a frequency which is in the vicinity of the Larmor frequencies to be detected of the nuclei to be excited in the object to be examined.
Claim 3
Dependent Claim
32 words
An apparatus as claimed in claim 1 wherein the at least one dielectric resonator has a central bore in the zero zone of the electric field strength of the excitable resonant mode.
Claim 4
Dependent Claim
51 words
An apparatus as claimed in claim 1 wherein the at least one dielectric resonator is proportioned so that a resonant mode involving two zero zones of an electric field strength can be excited, and in that in the zero zones there is a respective bore for introducing objects to be examined.
Claim 5
Dependent Claim
33 words
An apparatus as claimed in claim 1 wherein said at least one dielectric resonator includes two similar dielectric resonators wherebetween a clearance is created for the introduction of an object to be examined.
Claim 6
Dependent Claim
30 words
An apparatus as claimed in claim 1 wherein the dielectric of the dielectric resonator comprises a liquid which is introduced into a container which predetermines the shape of the resonator.
Claim 7
Dependent Claim
15 words
An apparatus as claimed in claim 5 wherein the liquid is water (H 2 O).
Claim 8
Dependent Claim
16 words
An apparatus as claimed in claim 6 wherein the liquid is heavy water (D 2 O).
Claim 9
Dependent Claim
46 words
An apparatus as claimed in claim 1 wherein the at least one dielectric resonator is proportioned so that therein two resonant modes can be excited with a phase shift of preferably approximately 90°, the magnetic fields of the resonant modes extending approximately perpendicular to one another.
Claim 10
Dependent Claim
33 words
An apparatus as claimed in claim 2 wherein the dielectric of the at least one dielectric resonator comprises a liquid which is introduced into a container which predetermines the shape of the resonator.
Claim 11
Dependent Claim
33 words
An apparatus as claimed in claim 3 wherein the dielectric of the at least one dielectric resonator comprises a liquid which is introduced into a container which predetermines the shape of the resonator.
Claim 12
Dependent Claim
33 words
An apparatus as claimed in claim 4 wherein the dielectric of the at least one dielectric resonator comprises a liquid which is introduced into a container which predetermines the shape of the resonator.
Claim 13
Dependent Claim
15 words
An apparatus as claimed in claim 9 wherein the liquid is water (H 2 O).
Claim 14
Dependent Claim
15 words
An apparatus as claimed in claim 10 wherein the liquid is water (H 2 O).
Claim 15
Dependent Claim
15 words
An apparatus as claimed in claim 11 wherein the liquid is water (H 2 O).
Claim 16
Dependent Claim
16 words
An apparatus as claimed in claim 9 wherein the liquid is heavy water (D 2 O).
Claim 17
Dependent Claim
10 words
The apparatus of claim 1 wherein the nuclei are protons.
Claim 18
Dependent Claim
10 words
The apparatus of claim 7 wherein the nuclei are pistons.
Claim 19
Dependent Claim
33 words
The apparatus as claimed in claim 8 wherein the dielectric of the at least one dielectric resonator comprises a liquid which is introduced into a container which predetermines the shape of the resonator.
Claim 20
Dependent Claim
160 words
A dielectric resonator for use in a magnetic resonance examination apparatus including a magnet system for generating a steady magnetic field in an examination space, a transmitter device for generating an RF field to be superposed on the steady magnetic field in an object to be examined and a device for detecting magnetic resonance signals generated in the object to be examined, said dielectric resonator comprising: a housing for a dielectric material; and a dielectric material in said housing, said housing and dielectric material being constructed so as to be adjacent to said object to be examined, said dielectric material having a relative dielectric constant ε r >20, the dimensions of said housing being chosen so that therein, using a neighboring transmitter of said apparatus, at least one resonance mode can be excited with a frequency which is in the vicinity of the Larmor frequencies to be detected of the nuclei to be excited in the object to be examined.
Claim 21
Dependent Claim
160 words
A dielectric resonator for use in a magnetic resonance examination apparatus including a magnet system for generating a steady magnetic field in an examination space, a transmitter device for generating an RF field to be superposed on the steady magnetic field in an object to be examined and a device for detecting magnetic resonance signals generated in the object to be examined, said dielectric resonator comprising: a housing for a dielectric material; and a dielectric material in said housing, said housing and dielectric material being constructed so as to be adjacent to said object to be examined, said dielectric material having a relative dielectric constant ε r >20, the dimensions of said housing being chosen so that therein, using a neighboring transmitter of said apparatus, at least one resonance mode can be excited with a frequency which is in the vicinity of the Larmor frequencies to be detected of the nuclei to be excited in the object to be examined.
Claim 22
Dependent Claim
28 words
The resonator of claim 19 wherein the housing has a central bore for placement in the zero zone of the electric field strength of the excitable resonant mode.
Claim 23
Dependent Claim
48 words
The resonator of claim 19 wherein the housing is proportioned so that a resonant mode of the resonator involving two zero zones of the electric field strength can be excited, and in that in the zero zones there is a respective bore for introducing objects to be examined.
Claim 24
Dependent Claim
21 words
The resonator of claim 19 including two similar resonators wherebetween there is a space for receiving an object to be examined.
Claim 25
Dependent Claim
23 words
The resonator of claim 19 wherein the dielectric material is a liquid contained in said housing which predetermines the shape of the resonator.
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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) | 1995-11-03 | 1996-05-04 | 1996-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-03 | 2000-05-04 | 2000-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-03 | 2004-05-04 | 2004-11-03 | $7700.00 | Window Closed / Lapsed |