RF coil apparatus for MR system with lateral B.sub.0 field
First Claim
1. RF coil apparatus for use in an MR imaging system, wherein the B0 magnetic field of the system is oriented in a specified direction, said RF coil apparatus comprising:
- a coil structure comprising a pair of elongated coil members in spaced-apart parallel relationship and further comprising a selected number of lateral coil members positioned along said elongated coil members in spaced-apart parallel relationship with one another, each lateral coil member coupled to both of said elongated coil members to form said coil structure, each of said lateral coil members respectively being aligned in parallel relationship with the direction of said B0 magnetic field so that said coil structure lies in a coil plane which is likewise aligned in parallel relationship with the direction of said B0 magnetic field, said coil plane comprising a hypothetical plane intersecting each of said elongated and lateral coil members of said coil structure; and
a number of first capacitive elements, each having a first capacitance, selectively positioned with respect to said elongated coil members;
a number of second capacitive elements, each having a second capacitance, selectively positioned with respect to said lateral coil members;
first coupling means for operating said coil structure to selectively transmit and receive a first RF field component directed along a first axis which is orthogonal to said B0 field direction; and
second coupling means for operating said coil structure to selectively transmit and receive a second RF field component directed along a second axis which is orthogonal to both said B0 field direction and said first axis, the frequencies of said first and second RF field components being equal to the same specified frequency.
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Accused Products
Abstract
RF coil apparatus is provided for use in an MR imaging system, wherein the B0 field is oriented in a specified direction. The apparatus comprises a coil structure positioned in selected relationship with the B0 field, the coil structure comprising a pair of elongated coil members in spaced-apart parallel relationship, and a selected number of lateral coil members positioned along the elongated coil members in spaced-apart parallel relationship with one another. A number of first capacitive elements, each of a first capacitance, are selectively positioned along the elongated coil members, and a second capacitive element is included in each of the lateral coil members, each of the second capacitive elements being of a second capacitance. A first coupling network operates the coil structure to selectively transmit and receive a first RF field component directed along a first axis which is orthogonal to the B0 field direction, the first RF field having a frequency determined by a specified relationship between the first and second capacitances. In like manner, a second coupling network operates the coil structure to selectively transmit and receive a second RF field component directed along a second axis which is orthogonal to both the B0 field direction and the first axis, the second RF field component having a frequency likewise determined by the relationship between the first and second capacitances, the first and second capacitances being respectively selected so that the frequencies thereof are equal.
46 Citations
17 Claims
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1. RF coil apparatus for use in an MR imaging system, wherein the B0 magnetic field of the system is oriented in a specified direction, said RF coil apparatus comprising:
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a coil structure comprising a pair of elongated coil members in spaced-apart parallel relationship and further comprising a selected number of lateral coil members positioned along said elongated coil members in spaced-apart parallel relationship with one another, each lateral coil member coupled to both of said elongated coil members to form said coil structure, each of said lateral coil members respectively being aligned in parallel relationship with the direction of said B0 magnetic field so that said coil structure lies in a coil plane which is likewise aligned in parallel relationship with the direction of said B0 magnetic field, said coil plane comprising a hypothetical plane intersecting each of said elongated and lateral coil members of said coil structure; and a number of first capacitive elements, each having a first capacitance, selectively positioned with respect to said elongated coil members; a number of second capacitive elements, each having a second capacitance, selectively positioned with respect to said lateral coil members; first coupling means for operating said coil structure to selectively transmit and receive a first RF field component directed along a first axis which is orthogonal to said B0 field direction; and second coupling means for operating said coil structure to selectively transmit and receive a second RF field component directed along a second axis which is orthogonal to both said B0 field direction and said first axis, the frequencies of said first and second RF field components being equal to the same specified frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An RF coil apparatus for use in an MR imaging system, wherein the B0 magnetic field of the system is directed along a specified B0 axis, said apparatus comprising:
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a selected number of inductive elements; a selected number of capacitors selectively coupled to said inductive elements to form a flat network, said network being aligned so that a hypothetical plane extending in parallel relationship with said B0 axis intersects each of said inductive elements and capacitors; and means for coupling said network to specified circuit components associated with an MR system in order to operate said network to produce a pair of degenerate resonant modes, both of said degenerate modes having the same resonant frequency, and to further operate said network in transmit and receive modes, selectively, said degenerate modes, when said network is operated in said transmit mode, each producing an RF magnetic field, said RF fields being orthogonal to each other in some region of space and collectively producing a circularly polarized RF field for exciting an MR signal, and said degenerate modes, when said network is operated in said receive mode, being disposed to receive an MR signal. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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Specification