# US 12,181,545 B2 · MR coil assembly with multiple dipole antennas and connection elements with blocking circuits > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,545 B2 - Document ID: US12181545B2 - Status: Granted - Kind: B2 - Application number: 17/434,220 - Filed: 2019-12-05 - Published: 2022-05-05 - Granted: 2024-12-31 - Earliest claimed: 2019-02-27 - Assignees: Forschungszentrum Julich GmbH - Applicants: Forschungszentrum Jülich GmbH - Inventors: Suk Min Hong; Nadim Joni Shah; Chang-Hoon Choi; Jörg Felder - Web page: https://patentgrep.com/patent/US12181545B2 ## CPC - G01R 33/3635: {Multi-frequency operation} - G01R 33/3664: {Switching for purposes other than coil coupling or decoupling, e.g. switching between a phased array mode and a quadrature mode, switching between surface coil modes of different geometrical shapes, switching from a whole body reception coil to a local reception coil or switching for automatic coil selection in moving table MR or for changing the field-of-view (G01R33/3671 takes precedence)} - A61B 5/055: involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging - G01R 33/34076: {Birdcage coils} - G01R 33/3415: comprising arrays of sub-coils {, i.e. phased-array coils with flexible receiver channels} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A coil assembly for use as a transmission and/or receiving coil in an MR system comprises a dipole antenna assembly with multiple dipole antennas. Connection elements are converted from an electrically conductive state to an electrically non-conductive state. In the electrically conductive state, the dipole antennas form a cylindrical volume coil and/or a conductor loop assembly, in particular a flat conductor loop assembly. The connection elements comprise blocking circuits which automatically block when a high-frequency alternating voltage with a frequency corresponding to the blocking frequency of the connection element blocking circuits is applied to the coil assembly. ## Claims ### Claim 1 A coil arrangement (1) for use as a transmitter and/or reception coil in an MR system, the coil arrangement (1) comprising a dipole antenna arrangement (2) with a plurality of dipole antennas (2a-d) connected to one another via connecting elements (3a-h), the connecting elements (3a-h) being designed to be transferred from an electrically connecting state to an electrically disconnecting state, and vice versa, and the arrangement configured so that the dipole antennas (2a-d) in the electrically connecting state of the connecting elements (3a-h) form at least a part of a volume coil and/or a conductor loop arrangement of the coil arrangement (1) comprising conductor loops (20a-c), wherein the connecting elements (3a-h) comprise connecting element blocking circuits (4a-h), which automatically block when a high-frequency AC voltage having a frequency corresponding to the blocking frequency of the connecting element blocking circuits (4a-h) is applied to the coil arrangement (1), wherein the coil arrangement (1) is configured so that the dipole antennas (2a-d) radiate and/or receive a high-frequency electromagnetic alternating field with a first frequency being the blocking frequency, when the connecting elements (3a-h) are in the electrically disconnecting state, wherein the volume coil resulting in the electrically connecting state of the connecting elements (3a-h) and/or each of the conductor loops (20a-c) of the conductor loop arrangement resulting in the electrically connecting state of the connecting elements (3a-h) radiates and/or receives a high-frequency, electromagnetic alternating field with a second frequency different from the first frequency, and wherein the first frequency is a 1H-core resonant frequency and the second frequency is an X-core resonant frequency. ### Claim 2 (depends on 1) The coil arrangement (1) according to claim 1, wherein the second frequency is a 31P-core resonant frequency or 23Na-core resonant frequency. ### Claim 3 (depends on 1) The coil arrangement (1) according to claim 1, wherein each of the dipole antennas (2a-d) comprises a rod-shaped base element (8a-d), at the axially opposite ends of which a conductor path segment (9a-h) adjoins respectively, the axial ends of the rod-shaped base element (8a-d) adjoining the respective conductor path segment (9a-h), and the conductor path segments (9a-h) of the dipole antennas (2a-d). ### Claim 4 (depends on 3) The coil arrangement (1) according to claim 3, wherein the rod-shaped base elements (8a-d) of the dipole antennas (2a-d) are arranged at least substantially parallel to one another and/or the rod-shaped base elements (8a-d) of the dipole antennas (2a-d) are arranged uniformly spaced apart from one another in the circumferential direction of the volume coil or in the longitudinal direction of the conductor loop arrangement and/or the length of the rod-shaped base elements (8a-d) of the dipole antennas (2a-d), the height of the volume coil or the width of the conductor loop arrangement is in the range from 25 to 30 cm. ### Claim 5 (depends on 3) The coil arrangement (1) according to claim 3, wherein the conductor path segments (9a-h) of the dipole antennas (2a-d) are connected to one another via the connecting elements (3a-h) to form two conductor paths (9). ### Claim 6 (depends on 1) The coil arrangement (1) according to claim 1, wherein at least one of the connecting element blocking circuits (4a-h) comprises a connecting element coil (5a-h) and a connecting element capacitor (6a-h), which are connected in parallel, wherein the connecting element coil (5a-h) has an inductance from 38 to 41 nH, and/or the connecting element capacitor (6a-h) has a capacitance from 6 to 8 pF. ### Claim 7 (depends on 6) The coil arrangement (1) according to claim 6, wherein at least one connecting element (3a-h) comprises a second connecting element capacitor (7a-h) which is connected in series with the connecting element blocking circuit (4a-h), the second connecting element capacitor (7a-h) having a capacitance from 5 to 50 pF. ### Claim 8 (depends on 7) The coil arrangement (1) according to claim 7, wherein the second connecting element capacitor (7a-h) is configured to tune the coil arrangement (1) to the second frequency. ### Claim 9 (depends on 3) The coil arrangement (1) according to claim 3, wherein the rod-shaped base elements (8a-d) of the dipole antennas (2a-d) are each separated to form two poles of the respective dipole antenna (2a-d). ### Claim 10 (depends on 9) The coil arrangement (1) according to claim 9, wherein the rod-shaped base elements (8a-d) of the dipole antennas (2a-d) have a junction device (11a-d) for connection to an AC voltage supply and/or scanning device, which comprises electrical junction elements (12a-d) connected to the two poles of the dipole antenna (2a-d). ### Claim 11 (depends on 2) The coil arrangement (1) according to claim 2, wherein the coil arrangement (1) is configured so that a feed and/or a tap of 1H-core signals and/or X-core signals can take place via the electrical junction elements (12a-d) of at least one junction device (11a-d). ### Claim 12 (depends on 1) The coil arrangement (1) according to claim 1, wherein the coil arrangement (1) is configured to be operated in a 4-channel and/or 2-channel quadrature mode. ### Claim 13 (depends on 11) The coil arrangement (1) according to claim 11, wherein the coil arrangement (1) is configured so that least one of a feed of X-core signal and a tap of X-core signals can take place via the electrical junction elements (12a-d) of a pair of two adjacent junction devices (11a-d). ### Claim 14 (depends on 13) The coil arrangement (1) according to claim 13, wherein the coil arrangement (1) is configured so that the volume coil and/or conductor loop arrangement resulting in the electrically connecting state of the connecting elements (3a-h) can be fed via the two adjacent junction devices (11a-d) in quadrature mode with a high-frequency AC voltage, whose frequency differs from the 1H-core resonant frequency and corresponds to an X-core resonant frequency in order to cause the volume coil or each conductor loop (20a-c) of the conductor loop arrangement to radiate a high-frequency alternating electromagnetic field having an X-core resonant frequency. ### Claim 15 (depends on 9) The coil arrangement (1) according to claim 9, wherein a dipole capacitor (13a-d) is in the center of a dipole antenna (2a-d) between the two poles, wherein the dipole capacitor (13a-d) is part of the junction device (11a-d), and wherein the dipole capacitor (13a-d) has a capacitance of 0 pF. ### Claim 16 (depends on 1) The coil arrangement (1) according to claim 1, wherein the dipole capacitor (13a-d) has a suitable capacitance to tune the coil arrangement (1) to the first frequency. ### Claim 17 (depends on 9) The coil arrangement (1) according to claim 9, wherein a coupling element (14a-d) is connected in parallel with the dipole capacitor (13a-d), which is electrically connected to and bridges the two poles of the dipole antenna (2a-d), and wherein the coupling element (14a-d) is transferred from an electrically connecting state to an electrically disconnecting state, and vice versa, and wherein the coupling element (14a-d) is part of the junction device (11a-d). ### Claim 18 (depends on 17) The coil arrangement (1) according to claim 17, wherein the coupling element (14a-d) comprises a coupling element blocking circuit (15a-d), which automatically blocks when a high-frequency AC voltage with a frequency corresponding to the blocking frequency of the coupling element blocking circuit (15a-d) is applied to the coil arrangement (1), and wherein the blocking frequency of the coupling element blocking circuit (15a-d) corresponds to the first frequency. ### Claim 19 (depends on 18) The coil arrangement (1) according to claim 18, wherein at least one of the coupling element blocking circuits (15a-d) comprises a coupling element coil (16a-d) and a coupling element capacitor (17a-d), which are connected in parallel, and wherein the coupling element coil (16a-d) has an inductance from 38 to 41 nH, and/or the coupling element capacitor (17a-d) has a capacitance from 6 to 8 pF. ### Claim 20 (depends on 19) The coil arrangement (1) according to claim 19, wherein at least one coupling element (14a-d) comprises a second coupling element capacitor (18a-d) connected in series with the coupling element blocking circuit (15a-d) of the coupling element (14a-d), the second coupling element capacitor (18a-d) having a capacitance from 20 to 110 pF. ### Claim 21 (depends on 1) The coil arrangement (1) according to claim 1, wherein the second coupling element capacitor (18a-d) is configured to tune the coil arrangement (1) to the second frequency and/or to trigger a short circuit at the second frequency. ### Claim 22 (depends on 20) The coil arrangement (1) according to claim 20, wherein the dipole antenna arrangement (2) comprises four dipole antennas (2a-d), wherein the second coupling element capacitors (18a-d) of the coupling elements (14a-d) of the junction devices (11a-d) of two adjacent dipole antennas (2a-d) each have an equal capacitance of 33 pF, and the second coupling element capacitors (17a-d) of the two remaining dipole antennas (2a-d) have a capacitance of 95 pF or 100 pF. ### Claim 23 (depends on 3) The coil arrangement (1) according to claim 3, wherein the axial ends of the rod-shaped base element (8a-d) of at least one dipole antenna (2a-d) each connect to the respective conductor path segment (9a-h) of the dipole antenna (2a-d) with the interposition of a junction point capacitor (10a-h), the junction point capacitor (10a-h) having a capacitance from 10 to 40 pF. ### Claim 24 (depends on 1) The coil arrangement (1) according to claim 1, wherein the junction point capacitor (10a-h) is configured to tune the coil arrangement (1) to the second frequency. ### Claim 25 (depends on 2) The coil arrangement (1) according to claim 2, wherein the coil arrangement (1) is tuned by the second connecting element capacitors (7a-h) and/or the second coupling element capacitors (18a-d) and/or the dipole capacitors (13a-d) and/or the junction point capacitors (10a-h) such, and wherein each dipole antenna (2a-d) in the electrically disconnecting state of the connecting elements (3a-h) and the coupling elements (14a-d) can radiate and/or receive a high-frequency electromagnetic alternating field with a 1H-core resonant frequency, and wherein the volume coil resulting in the electrically connecting state of the connecting elements (3a-h) and of the coupling elements (14a-d) and/or each conductor loop (20a-c) of the conductor loop arrangement resulting in the electrically connecting state of the connecting elements (3a-h) and of the coupling elements (14a-d) can radiate and/or receive a high-frequency electromagnetic alternating field with an X-core resonant frequency. ### Claim 26 (depends on 1) The coil arrangement (1) according to claim 1, wherein each conductor loop (20a-c) of the conductor loop arrangement resulting in the electrically connecting state of the connecting elements (3a-h) and of the coupling elements (14a-d) is formed at least by parts of two adjacent dipole antennas (2a-d). ### Claim 27 (depends on 26) The coil arrangement (1) according to claim 26, wherein at least a part of a dipole antenna (2a-d) forms part of two adjacent conductor loops (20a-c) and the capacitance values of the connecting element capacitors (6a-h) and/or of the second connecting element capacitors (7a-h) and/or of the coupling element capacitors (17a-d) and/or of the second coupling element capacitors (18a-d) and/or of the dipole capacitors (13a-d) and/or of the junction point capacitors (10a-h) and/or of further capacitors within the conductor loop arrangement are configured so that adjacent conductor loops (20a-c) are decoupled. ### Claim 28 (depends on 1) A MR system having the coil arrangement (1) according to claim 1. ### Claim 29 (depends on 1) Use of the coil arrangement (1) according to claim 1 as a high-frequency transmitter and/or reception coil in magnetic resonance imaging.