MR local coil with rotatable connection cable

Abstract

The invention relates to a MR local coil and a magnetic resonance apparatus. The MR local coil comprises an antenna unit having at least one antenna for receiving and / or transmitting HF signals, a connection cable for connecting the MR local coil to a magnetic resonance apparatus, a flat transmission element for transmitting energy and / or signals between the connection cable and the antenna unit. Wherein the transmission element is arranged at least partially helically around an axis of rotation.

Description

Technical Field

[0001] This invention relates to an MR local coil (magnetic resonance local coil) and a magnetic resonance device. Background Technology

[0002] In medical technology, imaging using magnetic resonance (MR), also known as magnetic resonance imaging (MRT, MRI), is characterized by high soft tissue contrast. Here, an excitation pulse is directed into the object being examined, typically a patient, using a magnetic resonance apparatus. This triggers a magnetic resonance signal within the patient. The magnetic resonance signal is received as measurement data by the magnetic resonance apparatus and used to reconstruct a magnetic resonance image.

[0003] Typically, the reception of magnetic resonance signals is achieved using so-called local coils, also commonly referred to as surface coils. These MR local coils usually include one or more MR antennas and are mounted close to the patient during the MRI examination.

[0004] Traditional MR local coils typically have an electrical connection to the MRI scanner for voltage supply and signal transmission. This is usually achieved via a connecting cable. The connecting cable extends from the local coil and contacts the MRI scanner via a plug-in connection. For patient examination, the local coil is also placed on the patient. They typically cover a portion of the patient's body and are not limited to a fixed position relative to the patient, depending on the area to be examined. In cases where the MR local coil can be flexibly positioned relative to the patient, different guidance for the connecting cable arises depending on how the MR local coil is arranged on the patient. Summary of the Invention

[0005] The technical problem to be solved by the present invention is particularly regarded as simplifying the operation of MR local coils, especially cable guides.

[0006] This objective is achieved through the features of the independent claim. Advantageous design options are described in the dependent claims.

[0007] Therefore, an MR local coil is proposed, comprising an antenna element having at least one antenna for receiving and / or transmitting high-frequency signals (HF signals). The MR local coil includes a connecting cable for connecting the MR local coil to a magnetic resonance device. The MR local coil includes a flat, particularly strip-shaped transmission element for transmitting, in particular, electrical energy and / or, in particular, electrical and / or optical signals, between the connecting cable and the antenna element. Here, the transmission element is arranged at least partially helically about a rotation axis, in particular wound around the rotation axis. Advantageously, the connecting cable is configured to rotate relative to the antenna element about the rotation axis at the connection point between the connecting cable and the antenna element.

[0008] Preferably, the transmission element is a spiral having at least one half-turn, particularly at least two turns, around the axis of rotation. Specifically, the transmission element describes a volute curve within a plane or layer. In particular, the transmission element does not resemble a screw, a coil, or a spiral.

[0009] The transmission element is designed to be flat. Specifically, it has a small thickness in the direction toward the axis of rotation. In particular, the transmission element has a strip shape. Preferably, the strip has a thickness at least three times, and especially five times, smaller than the width of the strip. Thus, the transmission element can be easily, particularly with little or no (mechanical) force consumption, drawn into its spiral shape.

[0010] The helical arrangement of the transmission element preferably describes a curve, especially a worm, that extends around the axis of rotation and particularly along the transmission element away from or close to the axis of rotation (depending on the observer's perspective). Depending on the state of rotation, the outer line of this curve may have a smaller or larger distance from the axis of rotation.

[0011] The transmitted HF signal is, for example, an excitation signal used to excite magnetic resonance signals, especially an excitation pulse. The received HF signal is, for example, a magnetic resonance signal, which is generated, particularly in the patient's body, by means of magnetic resonance.

[0012] Magnetic resonance devices may include, in particular, plug-in connection components, especially sockets, which can be plugged into complementary plug-in connection components of connecting cables. Signals and / or energy can be advantageously transmitted via this plug-in connection.

[0013] Connecting cables and / or transmission elements preferably have electrical conductors and / or optical conductors to transmit energy and / or signals.

[0014] Preferably, the connecting cable is detachably arranged on the (remaining) MR local coil, that is, the connecting cable can be removed without damaging the MR local coil.

[0015] Preferably, the axis of rotation is arranged on a surface perpendicular to the antenna element, particularly a plane. Preferably, this surface has a larger extension dimension relative to other possible surfaces of the MR local coil. Advantageously, the connecting cable can rotate relative to the antenna element at the connection point.

[0016] The antenna element of a freely placementable MR local coil (e.g., a so-called volume array) can be used on the patient in different relative positions (e.g., rotated 0° or 90°). Therefore, compared to MR head coils, which are typically not freely placementable, this MR local coil can generally change its position and its distance from the socket on the MRI machine (the socket can, for example, be arranged on the patient table of the MRI machine). By rotating the connecting cable, its length can be kept particularly short, thereby advantageously reducing the weight of the MR local coil. Patient safety is also improved when excessively long cables can be avoided to prevent entanglement on the patient.

[0017] Furthermore, rotatability allows for greater flexibility when operating the MR local coil, particularly when placing it on the patient's body. Advantageously, the guidance of the connecting cable, especially on the patient's body, can be designed in a patient-friendly manner.

[0018] Another embodiment of the MR local coil specifies that the transmission element includes a flexible circuit board. The flexible circuit board can be single-layered or multi-layered. Preferably, it may include an impedance control layer, particularly a 50-ohm layer. The flexible circuit board preferably has a thickness of 0.1 to 2 mm, particularly 0.2 to 0.8 mm, and especially 0.4 mm. The normal to the (planar) surface of the circuit board is preferably (substantially) perpendicular to the axis of rotation.

[0019] Due to the small thickness of the circuit board and / or its flexible material properties, the flexible circuit board can be advantageously and easily wound around a rotation axis. Preferably, an electrical conductor circuit, for example made of copper, is applied to the flexible circuit board, through which signals and / or energy can be transmitted.

[0020] Another embodiment of the MR local coil specifies that the transmission element includes a flat ribbon cable. The flat ribbon cable is preferably a multi-core cable, wherein the cores are guided parallel to each other. Signals and / or energy can be transmitted through the cores. Advantageously, the flat ribbon cable can be easily wound in a spiral around the axis of rotation.

[0021] Another embodiment of the MR local coil specifies that the antenna element includes multiple antennas, particularly coil elements, wherein the transmission elements include multiple electrical conductors and / or optical conductors arranged side by side for transmitting signals from the multiple antennas. These conductors can be implemented, in particular, as conductor circuits on a flexible circuit board and / or as core wires in a flat ribbon cable.

[0022] Each of the multiple antennas can be associated with a channel, particularly a transmit channel and / or a receive channel. If the antenna element comprises, for example, 16 antennas, it can be referred to as a 16-channel MR local coil.

[0023] In addition to the conductor associated with the defined channel, the transmission element may also include additional conductors, by means of which control information, coil identification data and / or electrical power may be transmitted, for example.

[0024] Another embodiment of the MR local coil specifies that the antenna element is constructed, particularly planar and / or flexible, especially in the form of a ceiling. For MR local coils with such an antenna element, the rotatability of the connecting cables is particularly advantageous, as these cables are typically placed on the patient in very different orientations. Advantageously, by connecting the connecting cables to the antenna element as proposed, the necessity of retracting excess connecting wires is eliminated, and the connecting wires do not cause deformation of the flexible antenna element at the coil connection due to suboptimal positioning.

[0025] Another embodiment of the MR local coil specifies that the MR local coil includes a housing having a first housing portion and a second housing portion, wherein a transmission element is arranged in the housing, and wherein the second housing portion is rotatable relative to the first housing portion about a rotation axis.

[0026] Preferably, the first and second housing portions are rigid. Advantageously, the housing protects the transmission element from external forces.

[0027] Preferably, the second housing portion is fixedly connected to the antenna unit. In particular, the first housing portion may further include multiple components, and the antenna unit may include at least one covering layer, which is clamped between the multiple components of the first housing portion.

[0028] Another embodiment of the MR local coil specifies that the housing has a slotted key connection, wherein the second housing portion is rotatable about a rotation axis relative to the first housing portion by means of the slotted key connection.

[0029] Preferably, the keyway connection is implemented circularly, wherein the axis of rotation extends through the center point of the circle. For example, the first housing member has a protrusion that engages in a recess (groove) surrounding the second housing member (around the circle). Thus, the second housing portion can be stably guided relative to the first housing portion during rotation about the axis of rotation.

[0030] Another embodiment of the MR local coil specifies that the housing has a stop portion that defines a possible rotational area about the rotation axis. Advantageously, this can prevent the transmission element from being overloaded due to excessive rotation.

[0031] Another embodiment of the MR local coil specifies that the second housing portion comprises two parts connected to each other by screws and / or latches. This advantageously simplifies the manufacture and / or installation of the second housing portion.

[0032] Another embodiment of the MR local coil specifies that the MR local coil includes a rigid-flex circuit board, wherein the transmission element is a flexible component of the rigid-flex circuit board, the rigid-flex circuit board includes a first rigid component connected to a first housing portion by means of a first connection, and the rigid-flex circuit board includes a second rigid component connected to a second housing portion by means of a second connection.

[0033] Advantageously, rigid-flex circuit boards are designed to ensure signal transmission even during numerous rotational cycles. In particular, rigid-flex circuit boards are implemented more space-efficiently than possible cable-stranded solutions. Advantageously, in addition to signal and / or energy guidance, other functions (position sensors, amplifiers, splitters, etc.) can be integrated on rigid-flex circuit boards.

[0034] Specifically, the flexible section has the shape of a belt arranged spirally around a rotation axis. A first rigid member of the rigid-flexible circuit board is arranged at a first end of the belt, and a second rigid member of the rigid-flexible circuit board is arranged at the other end of the belt, i.e., the second end.

[0035] The first connection and / or the second connection can be fixed, that is, the first and / or second rigid components of the rigid-flexible circuit board can be fixedly connected to the first or second rigid component.

[0036] Another embodiment of the MR local coil specifies that the first and / or second connections are configured to be detachable, for example, by means of an intermediate plug connection. Advantageously, this allows for easier repair of the MR local coil. For example, the connecting cable can be replaced more easily using the intermediate plug connection on the second housing portion. Advantageously, the rigid-flexible circuit board can be easily equipped with the intermediate plug connection, and the connecting wires can be replaced quickly and safely, for example, during assembly or possible repairs.

[0037] Another embodiment of the MR local coil specifies that the transmission element has a first end and a second end, wherein the transmission element is bent at the first end and / or the second end, in particular, by 90°. Specifically, the flexible component of the rigid-flexible circuit board has a first end and a second end, wherein the transmission element is bent at the first end and the second end, particularly by 90°.

[0038] Advantageously, the transmission element can thus be drawn out from the spirally arranged layers and / or planes. This enables, for example, easier connection to connecting cables and / or antenna units.

[0039] Another embodiment of the MR local coil specifies that the first housing portion and / or the second housing portion includes a gap extending perpendicular to the axis of rotation, through which the transmission element is guided.

[0040] Specifically, the bent first and / or second ends of the transmission element can pass through the slit. Advantageously, the gap serves as a linkage for the portion of the transmission element arranged helically around the axis of rotation. Thus, the helical portion is tensioned or relaxed as the connecting cable rotates relative to the antenna element.

[0041] Another embodiment of the MR local coil specifies that the housing includes a guiding element, wherein at least a portion of the transmission element that is helically arranged about a rotation axis is disposed in the guiding element and guided by the guiding element.

[0042] Furthermore, a magnetic resonance device is proposed, which has at least one of the aforementioned MR local coils.

[0043] Other advantages, features, and details of the invention become apparent from the embodiments described below and from the accompanying drawings. Corresponding parts are given the same reference numerals in all the drawings. In the drawings:

[0044] Figure 1 A schematic diagram of a magnetic resonance device with MR local coils is shown.

[0045] Figure 2 and Figure 3 An apparatus is shown having a transmission element for transmitting energy and / or signals between an antenna element and a connecting cable and an MR local coil.

[0046] Figure 4 The transmission element is shown in its deployed state.

[0047] Figure 5 The diagram shows a spiral-shaped transmission element in its first rotational state.

[0048] Figure 6 The image shows a spiral-shaped transmission element in its second rotational state.

[0049] Figure 7 The diagram shows elements of a device with a gap in which a transmission element is guided.

[0050] Figure 8 The intermediate housing used to house the transmission elements is shown. Detailed Implementation

[0051] exist Figure 1The image schematically illustrates a magnetic resonance imaging (MRI) device 10 having an MR local coil 100 arranged on a patient 15. The MRI device 10 includes a magnet unit 11 having a main magnet 12 for generating a strong and, in particular, time-constant main magnetic field 13. Furthermore, the MRI device 10 includes a patient receiving area 14 for accommodating the patient 15. In this embodiment, the patient receiving area 14 is cylindrically constructed and cylindrically surrounded in the circumferential direction by the magnet unit 11. However, in principle, a different construction of the patient receiving area 14 can be considered at any time. The patient 15 can be pushed into the patient receiving area 14 by means of a patient support device 16 of the MRI device 10. The patient support device 16 for this purpose has a patient table 17 movably designed within the patient receiving area 14.

[0052] The magnet unit 11 also includes a gradient coil unit 18 for generating a magnetic field gradient, which is used for position encoding during imaging. The gradient coil unit 18 is controlled by a gradient control unit 19 of the magnetic resonance apparatus 10. The magnet unit 11 also includes a high-frequency antenna unit 20, which in this embodiment is configured as a body coil fixedly integrated into the magnetic resonance apparatus 10. The high-frequency antenna unit 20 is controlled by a high-frequency antenna control unit 21 of the magnetic resonance apparatus 10 and radiates a magnetic resonance sequence in the form of a high-frequency (HF) signal into the examination space formed substantially by the patient reception area 14 of the magnetic resonance apparatus 10. Thus, the main magnetic field 13 generated by the main magnet 12 excites atomic nuclei. A magnetic resonance signal, which is also an HF signal, is generated by the relaxation of the excited atomic nuclei. The high-frequency antenna unit 20 is configured to receive the magnetic resonance signal. Furthermore, the MR local coil includes an antenna unit 120 with an antenna, which is also configured to receive and / or transmit HF signals. Advantageously, the antenna element 120 is flexible, for example constructed like a cover, so that the antenna can be installed particularly close to the patient's body 15.

[0053] The magnetic resonance apparatus 10 includes a system control unit 22 for controlling the main magnet 12, the gradient control unit 19, and the high-frequency antenna control unit 21. The system control unit 22 centrally controls the magnetic resonance apparatus 10, for example, by executing a predetermined imaging gradient echo sequence. Furthermore, the system control unit 22 includes an evaluation unit (not shown in detail) for evaluating the magnetic resonance signal detected during the magnetic resonance examination. Additionally, the magnetic resonance apparatus 10 includes a user interface 23 connected to the system control unit 22. Control information, such as imaging parameters and reconstructed magnetic resonance images, can be displayed on a display unit 24 of the user interface 23 for medical operators, such as on at least one monitor. Furthermore, the user interface 23 has an input unit 25 by which information and / or parameters can be input by the medical operator during the measurement process.

[0054] The MR local coil 100 is connected to a slot on the patient table 17 of the magnetic resonance device 10 via a connecting cable 116, through which signals and / or energy can be transmitted from and / or to the high-frequency antenna control unit 21.

[0055] A flat transmission element 107 for transmitting energy and / or signals between the connecting cable 116 and the antenna unit 120 is located at the connection point between the connecting cable 116 and the antenna unit 120 of the MR local coil, and this flat transmission element is shown in detail in the following figures. In particular, an embodiment is shown how the mechanical and electrical connection from the connecting cable to the antenna unit 120 of the MR local coil 100 can be rotatably designed.

[0056] As in Figure 2 and 3 As shown, the assembly consists of multiple housing portions that are rotatable relative to each other. A first housing portion 101 is fixedly connected to a local coil. For this purpose, the first housing portion may comprise, for example, two parts, between which the covering layer of the antenna element 120 can be sandwiched.

[0057] A wide housing portion comprising two parts 102 and 103 is rotatably supported relative to a first housing portion 101. A rotary joint is achieved via a keyway connection 104. For better assemblability, the first housing is divided into two parts 102 and 103, and connected to each other, for example, by screws or latches. A stop between the rotating components, i.e., the first housing portion 101 and the second housing portions 102 and 103, limits the rotation angle.

[0058] Contact via Figure 4 The rigid-flex circuit board 105 shown in the figure is used. The rigid-flex circuit board 105 includes two rigid components 106 and 108 and a flexible component in the form of a flexible circuit board forming a flat transmission element 107.

[0059] Rigid member 106 is fixedly connected to the first housing portion 101. Transmission element 107 forms a spiral by two bends and rolls at position AP, which can be tensioned by rotation like a coil spring (see [link]). Figure 6 ) or relaxation (see Figure 5 The first transmission element 107 is partially arranged in a spiral shape around the axis of rotation R.

[0060] The length of the transmission element 107 and the minimum winding diameter in the form of the limiting element 112 define the achievable rotation angle. The limiting element 112 prevents the conductor circuit of the transmission element 107 from breaking due to the continuous tension and slack of the helix. The longer the flexible component, the greater the achievable rotation angle of the connecting cable 116 relative to the antenna element 120 of the MR local coil.

[0061] A circuit board 114 is arranged on the second housing portion (102, 103), which, together with the second housing portion (102, 103), is rotatable relative to the first housing portion (101). The rigid component 108 of the rigid-flexible circuit board 105 includes a plug 113 (or socket) that is inserted into a socket 115 (or plug) on ​​the circuit board 114, thus forming a detachable connection. This intermediate plug-in connection allows for replacement of the connecting cable 116 of the MR local coil 100. Alternatively, this intermediate plug-in connection can be eliminated; then the rigid component 108 functionally corresponds to the rotatable circuit board 114. The connecting cable 116, which connects the MR local coil 100 to the magnetic resonance device 10, is connected to the rotatable circuit board 114, for example, by means of soldering. The rotatable circuit board 114 allows for more precise assembly and can be easily installed during the final assembly of the MR local coil 100 via the intermediate plug-in connection.

[0062] As in Figure 7 As can be seen, the rotatable circuit board 114 has a recess 117 that forms a form-fit with a pin in components 102 and 103 of the second housing portion. This form-fit serves as a linkage between the circuit board 114 and the second housing portions 102 and 103. The circuit board 114 has a gap 119. The angled end of the transmission element 107, which has a rigid member 108, is pushed into this gap 119 and thus reaches the plug 113 of the intermediate insertion connection. This gap 119 serves as a linkage for the helical transmission element 107, which is thus tensioned and relaxed as the circuit board 114 rotates. See [reference needed]. Figure 5 and 6 .like Figure 8 The intermediate housing shown serves as a guide element 118, in which the spiral transmission element 107 can be tensioned and relaxed; furthermore, it also serves as its guide. It is fixedly connected to the first housing portion 101.

[0063] The rotatability ideally always brings the connecting cable 116 from the output of the MR local coil 100 into its optimal position relative to the slot 26 of the magnetic resonance imaging device. This improves operation and optimizes the position of the connecting cable 116 on the patient 15. The rotatable implementation of the connecting cable 116 reduces the required cable length. This, in particular, results in fewer standing wave locks (or shaft locks) required for the connecting cable 116. Consequently, the flexibility of the connecting cable 116 is increased (the area of ​​the standing wave lock reinforces the connecting cable 116) and its weight is reduced.

[0064] Finally, it should be reiterated that the MR local coil and magnetic resonance device described in detail above are merely embodiments, which can be modified by those skilled in the art in the most different ways without departing from the scope of the invention. Furthermore, the use of the indefinite article "a" does not preclude the existence of multiple features. Similarly, the term "unit" does not preclude the existence of a component composed of multiple interacting sub-components that may be spatially distributed.

Claims

1. An MR local coil, comprising - Antenna element (120), said antenna element having at least one antenna for receiving and / or transmitting HF signals, - A connecting cable (116) for connecting the MR local coil (100) to the magnetic resonance device (10), - A flat transmission element (107) for transmitting energy and / or signals between the connecting cable (116) and the antenna unit (120), wherein, The connecting cable is configured to rotate relative to the antenna element about a rotation axis at the connection point between the connecting cable and the antenna element, wherein the transmission element (107) is arranged spirally at least partially about the rotation axis (R), wherein the transmission element is characterized by having at least a half-turn about the rotation axis.

2. The MR local coil according to claim 1, in, The transmission element (107) includes a flexible conductor plate and / or a flat ribbon cable.

3. The MR local coil according to any one of the preceding claims, in, The antenna unit (120) includes multiple antennas. The transmission element (107) includes a plurality of electrical conductors and / or optical conductors arranged side by side for transmitting signals from the plurality of antennas.

4. The MR local coil according to claim 1, in, The antenna element (120) is constructed in a planar manner.

5. The MR local coil according to claim 1, in, The antenna element (120) is flexibly constructed.

6. The MR local coil according to claim 1, in, The MR local coil (100) includes a housing having a first housing portion (101) and a second housing portion (102, 103). The transmission element (107) is disposed in the housing. The second housing portion (102, 103) is rotatable relative to the first housing portion (101) about the rotation axis (R).

7. The MR local coil according to claim 6, in, The housing includes a keyway connection (104). The second housing portion (102, 103) is rotatable about the rotation axis (R) relative to the first housing portion (101) by means of the slotted key connection (104).

8. The MR local coil according to claim 6 or 7, in, The housing has a stop and / or a limiting element (112) located inside the spiral layout, the limiting element limiting the rotational area about the axis of rotation (R).

9. The MR local coil according to claim 6, in, The MR local coil (100) includes a rigid-flexible circuit board (105). The transmission element is a flexible component of the rigid-flexible circuit board (105). The rigid-flex circuit board (105) includes a first rigid component, which is connected to the first housing portion (101) via a first connection. The rigid-flex circuit board (105) includes a second rigid component, which is connected to the second housing portion by means of a second connection.

10. The MR local coil according to claim 9, in, The first connection and / or the second connection are configured to be detachable.

11. The MR local coil according to claim 6, in, The first housing portion (101) and / or the second housing portion (102) include a gap (119) extending perpendicular to the axis of rotation. The transmission element (107) passes through the gap (119).

12. The MR local coil according to claim 6, in, The housing includes a guide element (118), In this embodiment, at least a portion of the transmission element (107) that is spirally arranged around the axis of rotation (R) is arranged in the guide element (118) and guided by the guide element.

13. The MR local coil according to claim 1, in, The transmission element (107) has a first end and a second end in a spiral arrangement around the rotation axis (R). The transmission element (107) is bent at the first end and / or at the second end.

14. The MR local coil according to claim 13, in, The transmission element (107) is bent at 90° at the first end and / or the second end.

15. A magnetic resonance device (10) having at least one MR local coil (100) according to any one of claims 1 to 14.

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