Multi-resonant T/R antenna for MR image generation
First Claim
1. A dual- or multi-resonant RF/MR transmit and/or receive antenna system, comprising:
- an antenna (1, 2) comprising an antenna coil (1) and at least one resonant circuit (2), the at least one resonant circuit (2) being serially connected into the antenna coil (1) in order to tune the antenna (1, 2) concurrently to at least two resonant frequencies corresponding to Larmor frequencies of two or more nuclei of interest;
an inductive coupling device including at least one coupling loop (L1, or L2) dimensioned and/or positioned in relation to the antenna (1, 2) such that the at least one coupling loop and the antenna (1, 2)a) are inductively coupled by a resulting magnetic flux occurring between the at least one coupling loop (L1, or L2) and the antenna (1, 2) at each of the concurrent resonant frequencies of the antenna (1, 2) andb) are impedance-matched to each of the RF/MR transmit and/or receive channels,wherein the at least one coupling loop (L1, or L2) is movably mounted to be mechanically displaced a physical distance (A) in relation to the antenna (1, 2) when adjusting the magnetic flux between the antenna (1, 2) and the inductive coupling device, with the inductive coupling being broadband such that concurrent tuning and matching is applied to all resonant frequencies permitting simultaneous MR imaging to be performed at each of the at least two resonant frequencies.
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Accused Products
Abstract
A dual- or multi-resonant RF/MR transmit and/or receive antenna (1, 2) especially in the form of a planar antenna or a volume array antenna (also called antenna array) is used for MR image generation of at least two different nuclei like e.g. 1H, 19F, 3He, 13C, 23Na or other nuclei having different Larmor frequencies. The antenna is coupled by an inductive coupling device (LI) with related transmit/receive channels (T/R). By such an inductive coupling, the tuning and matching of the antenna at the different resonant frequencies is easier than in case of a galvanic connection. The dual- or multi-resonant RF/MR transmit and/or receive antenna is used in an MR imaging apparatus.
21 Citations
17 Claims
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1. A dual- or multi-resonant RF/MR transmit and/or receive antenna system, comprising:
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an antenna (1, 2) comprising an antenna coil (1) and at least one resonant circuit (2), the at least one resonant circuit (2) being serially connected into the antenna coil (1) in order to tune the antenna (1, 2) concurrently to at least two resonant frequencies corresponding to Larmor frequencies of two or more nuclei of interest; an inductive coupling device including at least one coupling loop (L1, or L2) dimensioned and/or positioned in relation to the antenna (1, 2) such that the at least one coupling loop and the antenna (1, 2) a) are inductively coupled by a resulting magnetic flux occurring between the at least one coupling loop (L1, or L2) and the antenna (1, 2) at each of the concurrent resonant frequencies of the antenna (1, 2) and b) are impedance-matched to each of the RF/MR transmit and/or receive channels, wherein the at least one coupling loop (L1, or L2) is movably mounted to be mechanically displaced a physical distance (A) in relation to the antenna (1, 2) when adjusting the magnetic flux between the antenna (1, 2) and the inductive coupling device, with the inductive coupling being broadband such that concurrent tuning and matching is applied to all resonant frequencies permitting simultaneous MR imaging to be performed at each of the at least two resonant frequencies. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. An RF/MR transmit and/or receive antenna system comprising:
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an RF antenna concurrently and simultaneously tuned to magnetic resonance Larmor frequencies of first and second nuclei, the RF antenna including an antenna coil connected in series with a resonant circuit; an inductive coupling device configured to inductively couple the RF antenna with an RF/MR transmit and/or receive antenna system channel, the inductive coupling device being broadband and permitting a concurrent and simultaneous tuning and matching with the magnetic resonance Larmor frequencies of the first and second nuclei including; a coupling coil having a plurality of windings, the plurality of windings being disposed adjacent the antenna coil in order to inductively couple at least one winding of the plurality of windings to the antenna coil, and one or more diodes connected with the plurality of windings, the windings being configured to be biased between conductive and nonconductive states by applying a related bias voltage onto the one or more diodes in order to change a magnetic flux between the plurality of windings and the antenna coil in order to adjust the inductive coupling. - View Dependent Claims (16)
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17. A magnetic resonance antenna system configured for transmitting and/or receiving magnetic resonance signals concurrently at first and second magnetic resonance Larmor frequencies corresponding to first and second nuclei, the magnetic resonance antenna system comprising:
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an MR antenna configured to be concurrently resonant simultaneously at each of the first and second magnetic resonance Larmor frequencies; at least one resonant circuit serially connected to the MR antenna concurrently tuned to both the first and second magnetic resonance Larmor frequencies; a broadband coupling coil disposed adjacent the MR antenna such that the broadband coupling coil inductively couples to the MR antenna, at least at each of the first and second resonance frequencies, the broadband coupling coil also being directly coupled with a transmit and/or receive channel of the MR antenna system; and a motor configured to move the broadband coupling coil relative to the MR antenna a physical distance when adjustment of the inductive coupling between the MR antenna and the broadband coupling coil is required.
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Specification