US5107216A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nuclear magnetic resonance imaging apparatus
Assignee: Hitachi Healthcare Manufacturing Ltd
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Filing: 1990-02-01
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Granted: 1992-04-21
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Expires: 2010-02-01
Abstract
Abstract In an imaging apparatus using the nuclear magnetic resonance, a solenoid coil and a slot-resonator coil are combined with each other so as to constitute a quadrature-phase detection probe. In order to operate the slot-resonator coil at low frequency, inductance is added to the slot-resonator coil. Further in order to cut the coupling between a transmitting coil and a receiving coil in a cross coil system, a capacitor together with the added inductance to form a resonant circuit is connected in parallel to the inductance. A favorable probe can be obtained in a vertical-magnetic field type imaging apparatus.
Inventors
- 👤 Masao Yabusaki
- 👤 Etsuji Yamamoto
- 👤 Hiroyuki Takeuchi
- 👤 Hideki Kohno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:43
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/36; G01R33/3642; G01R33/3657; G01R33/34; G01R33/343
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
207 words
A nuclear magnetic resonance imaging apparatus comprising: static magnetic field generation means for generating a static magnetic field in a cylindrical space having an axis along a first direction, said static magnetic field generation means generating said static magnetic field in a second direction perpendicular to the first direction; a quadrature-phase detection probe for detecting a high-frequency magnetic field caused by nuclear magnetic resonance in said cylindrical space, said quadrature-phase detection probe including a slot-resonator coil and a solenoid coil; said slot-resonator coil having two conductive arms extending in parallel to the axis of said cylindrical space and positioned on opposite sides of the axis of said cylindrical space so as to be spaced apart from each other in the second direction, one of said two conductive arms having ends thereof capacitively coupled to corresponding ends of the other of said two conductive arms so that said slot-resonator coil has a sensitivity enabling detection of a high-frequency magnetic field component in a third direction perpendicular to the first and second directions; and said solenoid coil including a coil member wound around a circumference of said cylindrical space so that said solenoid coil has a sensitivity enabling detection of a high-frequency magnetic field component in the first direction.
Claim 2
Dependent Claim
207 words
A nuclear magnetic resonance imaging apparatus comprising: static magnetic field generation means for generating a static magnetic field in a cylindrical space having an axis along a first direction, said static magnetic field generation means generating said static magnetic field in a second direction perpendicular to the first direction; a quadrature-phase detection probe for detecting a high-frequency magnetic field caused by nuclear magnetic resonance in said cylindrical space, said quadrature-phase detection probe including a slot-resonator coil and a solenoid coil; said slot-resonator coil having two conductive arms extending in parallel to the axis of said cylindrical space and positioned on opposite sides of the axis of said cylindrical space so as to be spaced apart from each other in the second direction, one of said two conductive arms having ends thereof capacitively coupled to corresponding ends of the other of said two conductive arms so that said slot-resonator coil has a sensitivity enabling detection of a high-frequency magnetic field component in a third direction perpendicular to the first and second directions; and said solenoid coil including a coil member wound around a circumference of said cylindrical space so that said solenoid coil has a sensitivity enabling detection of a high-frequency magnetic field component in the first direction.
Claim 3
Dependent Claim
37 words
A nuclear magnetic resonance imaging apparatus according to claim 1, wherein at least one of said two conductive arms of said slot-resonator coil is divided into two parts, and further comprising an inductance connecting the divided parts.
Claim 4
Dependent Claim
53 words
A nuclear magnetic resonance imaging apparatus according to claim 1, further comprising: high-frequency magnetic field generation means for generating a high-frequency magnetic field in the third direction perpendicular to the first and second directions in the cylindrical space; and decoupling means providing in a current path in said slot-resonator coil for enabling decoupling.
Claim 5
Dependent Claim
69 words
A nuclear magnetic resonance imaging apparatus according to claim 3, wherein said decoupling means includes a series circuit of a capacitor and a switching element, and an inductance connected in parallel with said series circuit, said capacitor and said inductance resonating at a frequency of said high-frequency magnetic field generated by said high-frequency magnetic field generation means when said inductance enables coupling to said capacitor through said switching element.
Claim 6
Dependent Claim
78 words
A nuclear magnetic resonance imaging apparatus according to claim 4, wherein said switching element includes a pair of diodes connected in parallel to each other and having polarities opposite to each other, said pair of diodes presenting a low impedance under a voltage induced by said high-frequency magnetic field generated by said high-frequency magnetic field generation means and being in a non-conductive state under a voltage induced by said high-frequency magnetic field generated by said nuclear magnetic resonance.
Claim 7
Dependent Claim
61 words
A nuclear magnetic resonance imaging apparatus according to claim 1, wherein a portion of at least one of said coil member of said solenoid coil and at least one of said conductive arms of said slot-resonator coil at overlapped portions of said coil member and said at least one of said conductive arms is thinner in comparison with other portions thereof.
Claim 8
Dependent Claim
23 words
A nuclear magnetic resonance imaging apparatus according to claim 1, wherein each of said two conductive arms includes at least one slender conductor.
Claim 9
Dependent Claim
18 words
A nuclear magnetic resonance imaging apparatus according to claim 7, wherein said slender conductor is a copper rod.
Claim 10
Dependent Claim
46 words
A nuclear magnetic resonance imaging apparatus according to claim 1, further comprising: high-frequency magnetic field generation means for generating a high-frequency magnetic field in the first direction in the cylindrical space; and decoupling means provided in a current path in said solenoid coil for enabling decoupling.
Claim 11
Dependent Claim
69 words
A nuclear magnetic resonance imaging apparatus according to claim 9, wherein said decoupling means includes a series circuit of an inductance and a switching element, and a capacitor connected in parallel with said series circuit, said capacitor and said inductance resonating at a frequency of said high-frequency magnetic field generated by said high-frequency magnetic field generation means when said capacitor enables coupling to said inductance through said switching element.
Claim 12
Dependent Claim
78 words
A nuclear magnetic resonance imaging apparatus according to claim 10, wherein said switching element includes a pair of diodes connected in parallel to each other and having polarities opposite to each other, said pair of diodes presenting a low impedance under a voltage induced by said high-frequency magnetic field generated by said high-frequency magnetic field generation means and being in a non-conductive state under a voltage induced by said high-frequency magnetic field caused by said nuclear magnetic resonance.
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) | 1995-04-21 | 1995-10-21 | 1996-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-04-21 | 1999-10-21 | 2000-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-04-21 | 2003-10-21 | 2004-04-21 | $7700.00 | Window Closed / Lapsed |