Patent EP0317090A2 successfully refreshed from Google Patents.
EP0317090A2
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EP
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Localised coil arrangements for receiving signals from resonating nuclei
Assignee: Philips Nuclear Medicine Inc
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Filing: 1988-10-21
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Granted: —
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Expires: 2008-10-21
Abstract
Abstract The magnet (12) creates a main magnetic field along a z-axis through an image region. A localized coil (D) is disposed in the image region at least to receive magnetic resonance signals from nuclei of the subject which have been induced to resonance. The localized coil (D) includes an inner conductor (30), an outer conductor (32), and a dielectric material (52) therebetween. The outer conductor defines a gap (50) midway between its ends. One end of the inner conductor (30) is connected with a gate of an FET transistor (66) and the outer conductor (32) is connected with its source. The transistor source and drain are connected by a coaxial transmission cable (38) with a DC power supply (70) which provides a DC bias across the transistor source and drain. The cable (38) also connects the transistor with a radio frequency receiver (40) to convey preamplfied magnetic resonance signals thereto. The other end of the inner conductor (30) may be connected with the outer conductor (32) to provide an unbalanced localized coil or the ends may each be connected with an FET transistor (66a,66b) in a balanced coil arrangement.
Inventors
- 👤 George J. Misic
- 👤 G. Neil Holland
- 👤 Mehrdad Mehdizadeh
- 👤 John L. Patrick
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 11:27
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/36; G01R33/3621; G01R33/34; G01R33/34046; G01R33/341; G01R33/3628
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
138 words
A localised coil arrangement for receiving radio frequency signals from resonating nuclei characterised in that it comprises: an inner conductor (30) defining a first current path adjacent a surface of a subject; an outer conductor (32) defining a current path along the inner conductor (30) and at least partially therearound, the outer conductor (32) being disposed between the surface of the subject and the inner conductor (30), the outer conductor (32) having at least one opening (50) therein between the subject surface and the inner conductor (30); a connecting means (34) for electrically connecting adjacent first ends of the inner (30) and outer (32) conductors; and an interface means (36) connected with and adjacent second ends of the inner (30) and outer (32) conductors for interconnecting the conductors (30,32) with a cable (38) extending to a receiver (40).
Claim 2
Dependent Claim
138 words
A localised coil arrangement for receiving radio frequency signals from resonating nuclei characterised in that it comprises: an inner conductor (30) defining a first current path adjacent a surface of a subject; an outer conductor (32) defining a current path along the inner conductor (30) and at least partially therearound, the outer conductor (32) being disposed between the surface of the subject and the inner conductor (30), the outer conductor (32) having at least one opening (50) therein between the subject surface and the inner conductor (30); a connecting means (34) for electrically connecting adjacent first ends of the inner (30) and outer (32) conductors; and an interface means (36) connected with and adjacent second ends of the inner (30) and outer (32) conductors for interconnecting the conductors (30,32) with a cable (38) extending to a receiver (40).
Claim 3
Dependent Claim
25 words
An arrangement according to Claim 1 wherein the interface means (36) includes reactive elements (78) for matching the localized coil arrangement and the cable impedances.
Claim 4
Dependent Claim
32 words
An arrangement according to Claim 1 or Claim 2 wherein the interface means (36) further includes at least one active component (80,82) for selectively decoupling the coil arrangement from the cable (38).
Claim 5
Dependent Claim
18 words
An arrangement according to Claim 3 wherein said at least one active component (80,82) comprises PIN diodes (80,82).
Claim 6
Dependent Claim
15 words
An arrangement according to Claim 1 wherein the interface means (36) includes preamplifier means (64).
Claim 7
Dependent Claim
30 words
An arrangement according to Claim 5 wherein the preamplifier means (64) includes a transistor (66) with its gate or base connected with the second end of the inner conductor (30).
Claim 8
Dependent Claim
20 words
An arrangement according to Claim 6 further including a capacitor (60) connected between the inner (30) and outer (32) conductors.
Claim 9
Dependent Claim
55 words
An arrangement according to Claim 6 or Claim 7 wherein said transistor is an FET transistor (66) having its gate connected with the inner conductor (30), its source connected with the outer conductor (32) and with a first conductor of the cable (38), and its drain connected with a second conductor of the cable (38).
Claim 10
Dependent Claim
28 words
An arrangement according to Claim 8 further including a DC bias means (70) for applying a DC bias between the first and second conductors of the cable (38).
Claim 11
Dependent Claim
23 words
An arrangement according to Claim 8 or Claim 9 further including at least one reactive component (62) connected between the gate and source.
Claim 12
Dependent Claim
33 words
An arrangement according to any one of the preceding claims further including a high velocity factor dielectric material (52) disposed between the inner (30) and outer (32) conductors of the localized coil arrangement.
Claim 13
Dependent Claim
23 words
An arrangement according to any one of the preceding claims wherein the outer conductor (32) of the localized coil arrangement is generally semicircular.
Claim 14
Dependent Claim
33 words
An arrangement according to any one of the preceding claims further including at least one capacitor (90 or 92) connected in series with the inner conductor (30) between its first and second ends.
Claim 15
Dependent Claim
47 words
An arrangement according to any one of the preceding claims wherein the inner (30) and outer (32) conductors are arranged in a loop with their first and second ends adjacent and wherein the outer conductor opening (50) is disposed substantially midway between the first and second ends.
Claim 16
Dependent Claim
29 words
An arrangement according to any one of the preceding claims further including a pair of crossed diodes (110) electrically connected with the outer conductor (32) across the opening (50).
Claim 17
Dependent Claim
61 words
A magnetic resonance apparatus comprising: a main magnetic field generating means for generating a magnetic field through an examination region; a magnetic resonance excitation means for exciting magnetic resonance of nuclei of a subject in the examination region; and a localised coil arrangement according to any one of the preceding claims arranged to receive radio frequency signals from said resonating nuclei.
Claim 18
Dependent Claim
168 words
A localised coil arrangement for receiving radio frequency signals from resonating nuclei characterised in that it comprises: an inner conductor (30) defining at least one loop between first and second ends thereof; a Faraday shield means (32) including a first conductive portion extending along the inner conductor (30) from adjacent the first end of the inner conductor (30) and between the inner conductor (30) and the surface of a subject and a second conductive portion extending along the inner conductor (30) from adjacent the second end of the inner conductor (30) and between the inner conductor (30) and the surface of the subject, the first and second conductive portions defining a gap (5) therebetween; a first FET transistor (66a) having a gate connected with the first end of the inner conductor (30), a source connected with the Faraday shield (32) first and second conductive portions and by a transmission cable (38) to a receiver (40), and a drain connected by the transmission cable 38) to the receiver (40).
Claim 19
Dependent Claim
168 words
A localised coil arrangement for receiving radio frequency signals from resonating nuclei characterised in that it comprises: an inner conductor (30) defining at least one loop between first and second ends thereof; a Faraday shield means (32) including a first conductive portion extending along the inner conductor (30) from adjacent the first end of the inner conductor (30) and between the inner conductor (30) and the surface of a subject and a second conductive portion extending along the inner conductor (30) from adjacent the second end of the inner conductor (30) and between the inner conductor (30) and the surface of the subject, the first and second conductive portions defining a gap (5) therebetween; a first FET transistor (66a) having a gate connected with the first end of the inner conductor (30), a source connected with the Faraday shield (32) first and second conductive portions and by a transmission cable (38) to a receiver (40), and a drain connected by the transmission cable 38) to the receiver (40).
Claim 20
Dependent Claim
49 words
An arrangement according to Claim 17 further including a second FET transistor (66b) having its gate connected to the second end of the inner conductor (30), its source connected to the Faraday shield (32) first and second conductive portions, and a drain operatively connected with the transmission cable (38).
Claim 21
Dependent Claim
25 words
An arrangement according to Claim 18 further including an adjustable reactive load (60) connected between the first and second ends of the inner conductor (30).
Claim 22
Dependent Claim
54 words
An arrangement according to Claim 18 wherein the transmission cable (38) includes a pair of coaxial leads and further including a balun means (98) interconnecting the coaxial leads with the first and second FET transistors (66a,66b); and, a DC voltage supply (70) operatively connected with the coaxial leads for applying a DC bias thereacross.
Claim 23
Dependent Claim
64 words
A magnetic resonance apparatus comprising: a main magnetic field generating means (A) for generating a magnetic field through an examination region; a magnetic resonance excitation means (C) for exciting magnetic resonance of nuclei of a subject in the examination region; and a localised coil arrangement according to any one of Claims 17 to 20 arranged to receive radio frequence signals from said resonating nuclei.
Claim 24
Dependent Claim
150 words
A magnetic resonance method comprising: disposing a subject in a magnetic field; disposing an inner conductor (30) adjacent a surface of the subject; disposing an outer conductor (32) parallel to the inner conductor (30) and between the inner conductor (30) and the subject, the outer conductor (32) having an electrical discontinuity (50) therein; connecting the outer conductor (32) with a ground; connecting at least one end of the inner conductor (30) with a preamplifier (64), which preamplifier (64) is disposed adjacent the inner conductor (30) and the patient surface within the magnetic field; connecting the preamplifier (64) with a radio frequency receiver (40); exciting magnetic resonance of nuclei in the subject such that radio frequency magnetic resonance signals are generated; receiving the magnetic resonance signals with the inner conductor (30), amplifying the magnetic resonance signals with the preamplifier (64), and conducting the amplified magnetic resonance signals to the receiver (40).
Claim 25
Dependent Claim
150 words
A magnetic resonance method comprising: disposing a subject in a magnetic field; disposing an inner conductor (30) adjacent a surface of the subject; disposing an outer conductor (32) parallel to the inner conductor (30) and between the inner conductor (30) and the subject, the outer conductor (32) having an electrical discontinuity (50) therein; connecting the outer conductor (32) with a ground; connecting at least one end of the inner conductor (30) with a preamplifier (64), which preamplifier (64) is disposed adjacent the inner conductor (30) and the patient surface within the magnetic field; connecting the preamplifier (64) with a radio frequency receiver (40); exciting magnetic resonance of nuclei in the subject such that radio frequency magnetic resonance signals are generated; receiving the magnetic resonance signals with the inner conductor (30), amplifying the magnetic resonance signals with the preamplifier (64), and conducting the amplified magnetic resonance signals to the receiver (40).
References Cited (Backward Citations)
No citation records indexed.
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