Radio frequency coil system and magnetic resonance imaging equipment

Abstract

The radio frequency coil system for magnetic resonance imaging equipment provided by the present invention comprises: a cylindrical body; a radio frequency coil disposed around the cylindrical body, the radio frequency coil including multiple feed ports spaced apart along its circumference; and multiple feed assemblies disposed on the cylindrical body, the feed assemblies corresponding one to each of the feed ports and connected to the corresponding feed ports. Compared to existing technologies, the present invention, by providing multiple feed ports and corresponding multiple feed assemblies, achieves a more uniform distribution of the radio frequency field generated by the radio frequency coil, thereby improving magnetic resonance imaging results.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a radio frequency coil system and a magnetic resonance imaging device. Background Art

[0002] like Figure 1 As shown, Figure 1 It is a radio frequency coil system of the prior art, comprising a cylinder 01, a body radio frequency coil 02 arranged around the cylinder, and a feeding port 03 and a power supply port 04 provided on the cylinder. The feeding port 03 generates a radio frequency signal and transmits it to the body radio frequency coil, and the power supply port 04 generates a DC signal and transmits it to the body radio frequency coil. In the prior art, two feeding ports 03 are provided on the cylinder, and the two feeding ports are usually symmetrical about the central axis of the cylinder 02 along the radial direction of the cylinder 02. The radio frequency fields generated by the two feeding ports 03 are relatively unevenly distributed; the two power lines of the two feeding ports 03 are connected to the nearest line and are not brought together for unified grounding, which can easily cause phase deviation of the radio frequency signal, and at the same time, the common mode signal is not effectively suppressed; the power line of the feeding port 03 and the power supply line of the power supply port are both connected to the same end along the axial direction of the cylinder 02 ( Figure 1 In the example, both wires exit at the left end of the cylinder). Although this has advantages from the perspective of magnetic resonance services, there is a risk of interference between RF and DC signals. Summary of the Invention

[0003] The object of the present invention is to provide a radio frequency coil system and a magnetic resonance imaging device to solve the problem of uneven radio frequency field generated by the existing radio frequency coil system.

[0004] To solve the above technical problems, according to one aspect of the present invention, the present invention provides a radio frequency coil system, comprising:

[0005] Cylinder;

[0006] a radio frequency coil, which is arranged around the cylindrical body, and includes a plurality of feeding ports arranged at intervals along the circumference of the radio frequency coil;

[0007] A plurality of feeding components are arranged on the cylindrical body, the feeding components correspond to the feeding ports one by one, and the feeding components are connected to the corresponding feeding ports.

[0008] Optionally, a plurality of the feeding assemblies are arranged at intervals along the circumference of the cylinder, and at least a portion of the feeding assemblies are arranged circumferentially.

[0009] Optionally, the feeding component includes a power line and a wave limiter, one end of the power line is connected to the feeding port to transmit a driving signal; the wave limiter is used to limit the driving signal of a preset frequency to be transmitted to the radio frequency coil.

[0010] Optionally, the power line leads to a power supply end at one end connected to the feeding port, and the power supply ends of at least two feeding components converge to form a wiring harness group, which is fixed at a preset position at one end of the cylinder along the axial direction.

[0011] Optionally, the power supply ends of all the feeding components are gathered into one harness group.

[0012] Optionally, the RF coil system further includes a power supply assembly, the power supply assembly including a power supply line connected to the RF coil; the feed assembly includes a power line connected to the RF coil; the end of the power line other than the end connected to the RF coil and the end of the power line other than the end connected to the RF coil are distributed on both sides of the cylinder along its own axis.

[0013] Optionally, the RF coil system further includes a plurality of tuning components and a plurality of coupling components spaced apart along the circumference of the cylinder; the adjustment ends of the plurality of tuning components are located on one side of the cylinder along the axial direction; and the adjustment ends of the plurality of coupling components are located on one side of the cylinder along the axial direction.

[0014] Optionally, the tuning component includes a tuning rod and a tuning capacitor; the coupling component includes a coupling rod and a coupling capacitor.

[0015] Optionally, the cylinder has a plurality of grooves, which are recessed radially inwardly of the cylinder, and at least a first portion of the grooves are used to accommodate the tuning capacitor, and at least a second portion of the grooves are used to accommodate the coupling capacitor.

[0016] According to another aspect of the present invention, the present invention further provides a magnetic resonance imaging device, which includes the radio frequency coil system as described above.

[0017] In summary, the RF coil system and magnetic resonance imaging device provided by the present invention include: a cylindrical body; an RF coil disposed around the cylindrical body, the RF coil including multiple feed ports spaced apart along its circumference; and multiple feed assemblies disposed on the cylindrical body, each corresponding to each feed port. Each feed assembly is connected to the corresponding feed port to transmit a drive signal to the RF coil. Compared to the prior art, the present invention, by providing multiple feed ports and corresponding multiple feed assemblies, makes the RF field generated by the RF coil more uniformly distributed, thereby improving magnetic resonance imaging results. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0019] Figure 1 is a schematic diagram of a prior art radio frequency coil system;

[0020] Figure 2 and Figure 3 is a schematic diagram of a radio frequency coil system according to an embodiment of the present invention;

[0021] Figure 4 is a schematic diagram of a radio frequency coil according to an embodiment of the present invention;

[0022] Figure 5 yes Figure 4 Equivalent diagram of the medium RF coil;

[0023] Figure 6 is an equivalent diagram of a loop of a radio frequency coil according to an embodiment of the present invention;

[0024] Figure 7 and Figure 8 yes Figure 3 Enlarged view of part A in the middle;

[0025] Figure 9 is a schematic diagram of a cylinder according to an embodiment of the present invention;

[0026] Figure 10 yes Figure 3 Enlarged view of middle part B;

[0027] Figure 11 Schematic diagram of a switch unit according to an embodiment of the present invention.

[0028] In the attached figure:

[0029] 01-Cylinder; 02-RF coil; 03-Feeding port; 04-Power supply port;

[0030] 10-cylinder; 11-first wiring groove; 110-preset position; 12-second wiring groove; 13-groove;

[0031] 20-RF coil; 200-feeding port; 21-crossbar; 210-crossbar subunit; 22-end; 220-end subunit; LOOP-loop;

[0032] 30-feeding assembly; 31-power line; 310-wiring harness group; 32-wave limiter; 41-power supply line; 50-tuning assembly; 51-tuning rod; 52-tuning capacitor; 53-tuning sleeve; 54-coupling capacitor; 60-preset fixed capacitor. DETAILED DESCRIPTION

[0033] To make the objects, advantages, and features of the present invention more clearly apparent, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale. They are only used to conveniently and clearly assist in illustrating the purposes of the embodiments of the present invention. In addition, the structures shown in the drawings are often part of the actual structure. In particular, different drawings may need to illustrate different focuses and sometimes use different scales.

[0034] As used in the present invention, the singular forms "a", "an", and "the" include plural objects, the term "or" is generally used to include the meaning of "and / or", the term "several" is generally used to include the meaning of "at least one", and the term "at least two" is generally used to include the meaning of "two or more". In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first", "second", and "third" may explicitly or implicitly include one or at least two of the features, unless the content clearly indicates otherwise.

[0035] The present invention provides a radio frequency coil system and a magnetic resonance imaging device to solve the problem of uneven radio frequency field generated by the existing radio frequency coil system.

[0036] The following description is given with reference to the accompanying drawings.

[0037] like Figure 2 and Figure 3 As shown, Figure 2 and Figure 3 The figure is a schematic diagram of a radio frequency coil system according to an embodiment of the present invention. This embodiment provides a radio frequency coil system comprising: a cylindrical body 10; a radio frequency coil 20 disposed around the cylindrical body 10, the radio frequency coil 20 including a plurality of feed ports 200 spaced apart along its circumference; and a plurality of feed assemblies 30 disposed on the cylindrical body 10, each corresponding to each feed port 200. Each feed assembly 30 is connected to a corresponding feed port 200 to transmit a drive signal (e.g., a radio frequency drive signal) to the radio frequency coil 20. In this embodiment, the cylindrical body 10 is generally annular in shape. The scanning cavity of the cylindrical body 10 is used to load an examination object and perform scanning imaging under magnetic resonance imaging equipment.

[0038] Optionally, the RF coil system can be connected to a control system, which may include an FPGA (Field-Programmable Gate Array) control unit, a digital to analog converter (DAC), an RF amplifier, and a power divider connected in sequence, wherein the RF sequence transmitted by the FPGA control unit is converted into an analog signal by the DAC, amplified by the RF amplifier, and then converted into a drive signal by the power divider and sent to multiple feeding ports 200 of the RF coil 20, thereby driving the RF coil 20 to generate a circularly polarized field.

[0039] The RF coil 20 is a key component of the MRI device. It can have a transmitting function, or both a transmitting and receiving function. In this embodiment, the RF coil 20 has both transmitting and receiving functions. Specifically, when the RF coil 20 is in the transmitting state, it transmits RF pulses toward the subject, generating a RF field. This energy is absorbed by atoms containing odd numbers of protons (such as hydrogen atoms) in the subject's body, causing them to resonate. When the RF coil 20 is in the receiving state, it receives MR signals (similar to radio waves) generated by the resonating atoms in the subject's body.

[0040] Furthermore, the RF coil 20 of this embodiment can be a body transmit coil, or even more specifically, a degenerate birdcage coil. The RF coil system described above, by providing a plurality of feed ports 200 spaced apart along the circumference of the RF coil 20 and corresponding feed assemblies 30, can generate a more uniform RF field when the RF coil 20 is in a transmitting state than conventional RF coils 20, thereby improving the clarity and quality of magnetic resonance imaging, thereby facilitating the operator's determination of the cause of the patient's pathology.

[0041] Further, if Figure 4 and Figure 5 As shown, Figure 4 is a schematic diagram of a radio frequency coil according to an embodiment of the present invention. Figure 5 yes Figure 4The equivalent diagram of the RF coil in the figure shows that the RF coil 20 includes multiple cross-pieces 21 and two end portions 22. The cross-pieces 21 are provided with cross-end antennas, and the end portions 22 are provided with end ring antennas. The end portions 22 are provided at both ends of the cross-pieces 21 and at both ends between two adjacent cross-pieces 21, and the cross-pieces 21 are respectively connected to the end portions 22 at both ends. The multiple cross-pieces 21 are arranged at intervals (preferably uniform intervals) along the circumference of the RF coil 20, and the cross-pieces 21 extend along the axial direction of the RF coil 20. The crossbar portion 21 includes a plurality of crossbar subunits 210 arranged adjacent to each other along the axial direction of the RF coil 20. Adjacent crossbar subunits 210 are connected by capacitors. Typically, two adjacent crossbar subunits 210 located in the middle of the crossbar portion 21 are connected by a fixed capacitor. The crossbar subunits 210 near the end 22 of the crossbar portion 21, or the crossbar subunits 210 on the crossbar portion 21 that are connected to the end 22, are connected by an adjustable capacitor (i.e., the capacitance value of the capacitor can be adjusted). This arrangement allows the error of each fixed capacitor to be adjusted by the adjustable capacitor, thereby achieving precise transmission frequency calibration. Furthermore, each end 22 includes a plurality of end subunits 220, which are arranged at intervals along the circumference of the RF coil 20, thereby forming a ring-shaped end 22.

[0042] In this embodiment, two adjacent crosspieces 21 together with a plurality of end subunits 220 located between the two crosspieces 21 form a loop LOOP. It can be seen that the RF coil 20 includes a plurality of loops LOOP arranged along the circumferential direction, and the number of loops LOOP is equal to the number of crosspieces 21 of the RF coil 20. It can be further seen that the number of feeding ports 200 in this embodiment is equal to the number of loops LOOP, that is, one feeding port 200 acts on one loop LOOP. Optionally, the position of the feeding port 200 can be set on the end 22, for example, in this embodiment (see Figure 5 ), multiple feeding ports 200 are arranged on the same end 22 at intervals along the circumference of the RF coil 20, that is, the feeding ports 200 are located on the end sub-unit 220.

[0043] Furthermore, two adjacent cross-piece sub-units 210 can be connected via a fixed capacitor or an adjustable capacitor. In this embodiment, taking into account the different positional accuracy between the loops LOOP when the RF coil 20 is installed on the cylinder 10 and the deviation of the fixed capacitors connected between the cross-piece sub-units 210, this embodiment preferably configures the two adjacent cross-piece sub-units 210 to be connected via an adjustable capacitor to achieve adjustment of the resonant frequency of different loops LOOP, thereby achieving precise resonant frequency adjustment of the RF coil 20.

[0044] For further information, please refer to Figure 6 , Figure 6LOOP is an equivalent diagram of the loop of the radio frequency coil 20 according to an embodiment of the present invention. Figure 6 The current flow direction of one of the loops LOOP is exemplarily indicated. It should be noted that the current flow directions of multiple loops LOOP can be the same or different, depending on the amplitude and phase of the power supply current of each loop LOOP. Those skilled in the art can configure it according to actual conditions, and this embodiment will not be described in detail.

[0045] In one embodiment, the current flowing through the loop LOOP of the RF coil 20 is distributed in a discrete form, and the current corresponding to the nth LOOP is approximately:

[0046]

[0047] Among them, J leg (n) is the current on the th loop; N is the total number of loops. For example, when N is 12, the loops 1 to 12 are counted clockwise. The currents on the 1st and 6th loops are the largest. Correspondingly, different current source signals can be provided for different loops. Of course, it is understandable that each feed assembly 30 can be connected to a different power amplifier, and the amplitude and phase of the drive signal generated by each power amplifier can be independently set, that is, the amplitude and phase of the drive signal for each loop can be independently set.

[0048] Based on the above principles, the RF coil system configured in this embodiment also includes multiple tuning components 50 and multiple coupling components spaced apart along the circumference of the cylinder 10. The tuning components 50 are used to adjust the resonant frequency of the RF coil 20 to achieve precise correction of the transmission frequency. The adjustment ends of the multiple tuning components 50 are located on one side of the cylinder 10 along the axial direction. The coupling components are used to adjust the loop coupling of the RF coil 20, that is, to adjust the degree of coupling between adjacent loops. The adjustment ends of the multiple coupling components are located on one side of the cylinder 10 along the axial direction. Here, the adjustment end of the tuning component refers to the part of the tuning component used for tuning by the operator; the adjustment end of the coupling component refers to the part of the coupling component used for coupling by the operator (adjusting the coupling between loops). The adjustment ends of the multiple tuning components 50 are located on one side of the cylinder 10 along the axial direction, and the adjustment ends of the multiple coupling components are located on one side of the cylinder 10 along the axial direction, including two situations: (1) the adjustment ends of the multiple tuning components 50 are located on one side of the cylinder 10 along the axial direction, and the adjustment ends of the multiple coupling components are located on the other side of the cylinder 10 along the axial direction, such as the adjustment end of the tuning component 50 is on the left side and the adjustment end of the coupling component is on the right side; (2) the adjustment ends of the multiple tuning components 50 and the adjustment ends of the multiple coupling components are simultaneously located on one side of the cylinder 10 along the axial direction, such as both are located on the left side or the right side of the cylinder 10. Such a configuration makes it easier for operators to uniformly tune and / or couple on one side of the cylinder 10, which is more convenient and faster to implement.

[0049] Considering that each fixed capacitor has a certain error, the error of the fixed capacitor can be adjusted by the tuning component 50 to achieve accurate transmission frequency calibration. Figure 7 and Figure 8 , Figure 7 and Figure 8 yes Figure 3 The enlarged view of the middle A part shows that the tuning assembly 5050 includes a tuning rod 51 and a tuning capacitor 52. The tuning capacitor 52 is arranged on the RF coil 20. The tuning capacitors 52 of the multiple tuning assemblies 50 are located on the same side along the axial direction of the cylinder 10. The tuning rod 51 extends along the axial direction of the cylinder 10 and is rotatably connected to the tuning capacitor 52. The tuning rod 51 is used to rotate around its own axial direction to adjust the capacitance value of the tuning capacitor 52. Please refer to Figure 7 For the tuning capacitor 52 set in the cross-piece 21, after the tuning rod 51 rotates, the relative distance or facing area of ​​the metal sheets inside the tuning capacitor 52 is changed, thereby changing the resistance value of the tuning capacitor 52 and further adjusting the resonant frequency of the RF coil.

[0050] Please refer to Figure 8The coupling capacitor 54 is disposed on the end portion 22 and is used to connect two adjacent end subunits 220. For example, among three adjacent end subunits 220, the first end subunit 220 and the second end subunit 220 may be connected via a preset fixed capacitor 60, while the second end subunit 220 and the third end subunit 220 are connected via the coupling capacitor 54. When the coupling rod of the coupling capacitor 54 is rotated, the relative distance or facing area of ​​the metal sheets within the coupling capacitor 54 changes, thereby changing the resistance of the coupling capacitor 54, thereby achieving decoupling between adjacent loops and preventing damage to the RF coil 20.

[0051] The tuning assembly includes a tuning rod and a tuning capacitor. The tuning capacitor is arranged on the RF coil 20, and the tuning capacitors of the multiple tuning assemblies are located on the same side along the axial direction of the cylinder 10; the tuning rod extends along the axial direction of the cylinder 10 and is rotatably connected to the tuning capacitor. The tuning rod is used to rotate around its own axial direction to adjust the capacitance value of the tuning capacitor. Specifically, the tuning capacitor is arranged on (can be welded) the crossbar 21, and is used to connect two adjacent crossbar sub-units 210 near the end 22 on the crossbar 21, or to connect the end 22 and a crossbar sub-unit 210 of the crossbar 21 (the crossbar sub-unit 210 located at one end of the crossbar 21, such as the leftmost crossbar sub-unit 210). After the tuning rod rotates, the relative distance or facing area between the metal sheets inside the tuning capacitor is changed, thereby changing the capacitance value and correcting the RF transmission frequency offset caused by the physical error of the fixed capacitor. It should be noted that the figure shows the specific structure of the tuning component 50. The specific structure of the coupling component is roughly the same as that of the tuning component 50 and is not shown here again.

[0052] Furthermore, a tuning sleeve 53 can be provided on the tuning rod 51, with a gap between the tuning sleeve 53 and the tuning capacitor 52 to expose a portion of the tuning rod 51. In practice, in magnetic resonance imaging equipment, since the RF coil 20 is mounted inside the gradient coil, the capacitance of the tuning capacitor 52 can only be changed by twisting the slender tuning rod 51 within the limited space. Typically, a flat-blade screwdriver is used to twist the exposed portion of the tuning rod 51. The aforementioned "adjustable ends of the multiple tuning assemblies 50 are located on one side of the cylindrical body 10 along the axial direction" means that the portions of the tuning rods 51 of the multiple tuning assemblies 50 exposed from the tuning sleeve 53 are located on the same side of the cylindrical body 10, facilitating operation by technicians. Similarly, a coupling sleeve is also provided on the coupling rod. The arrangement of the coupling rod and the coupling sleeve in the coupling assembly, as well as the method for twisting the coupling rod, can be referred to in the corresponding configuration of the tuning assembly 50 and will not be further described here.

[0053] For multi-channel RF coils 20, frequency and coupling adjustment are very complex. A common adjustment method is to use adjustable capacitors as described above to simplify the design and facilitate adjustment, namely the tuning capacitor 52 and coupling capacitor 54 mentioned above. However, in high-pass RF fields, the voltage-resistant tuning capacitor 52 and coupling capacitor 54 are large in size and will occupy a large space when placed in the RF coil system. Figure 9 As shown, Figure 9 1 is a schematic diagram of a cylinder 10 according to an embodiment of the present invention. In view of this, this embodiment further provides a plurality of grooves 13 on the cylinder 10. The grooves 13 are recessed radially inwardly along the cylinder 10. At least the first portion of the grooves 13 is used to accommodate the tuning capacitor 52, and at least the second portion of the grooves 13 is used to accommodate the coupling capacitor 54. In this way, the tuning capacitor 52 and the coupling capacitor 54 can be sunk into the cylinder 10, simplifying the space design. Preferably, there is a gap between the coupling capacitor 54 and the tuning capacitor 52 and the grooves 13, that is, they are not in contact with the grooves 1323. It can be understood that the tuning capacitor 52 and the coupling capacitor 54 are suspended in the grooves 13. Such an arrangement can reduce the risk of overheating of the inner wall of the cylinder 10 caused by heat generated by the tuning capacitor 52 and the coupling capacitor 54 under high-power operation, thereby avoiding negative effects on the inspection object.

[0054] As a more preferred solution of this embodiment, please continue to refer to Figure 2 and Figure 3 The plurality of feed assemblies 30 are spaced apart along the circumference of the cylindrical body 10, preferably equidistantly distributed along the circumference. At least a portion of the feed assemblies 30 are circumferentially arranged, and preferably all of the feed assemblies 30 are circumferentially arranged. This facilitates structural layout and regular distribution of the overall device. It should be noted that whether the feed assemblies 30 are circumferentially arranged does not affect the uniformity of the RF field.

[0055] In some other embodiments, at least a portion of the feeding components 30 are spaced apart along the axial direction of the cylinder 10, that is, at least a portion of the feeding components 30 are not arranged on the same circumference. For example, one feeding component 30 may be moved a distance to the left side of the cylinder 10, and another feeding component 30 may be moved a distance to the right side.

[0056] Furthermore, the feed assembly 30 includes a power line 31 and a limiter 32. One end of the power line 31 is connected to the feed port 200 to transmit the drive signal, that is, connected to the end subunit 220 of the end 22 of the RF coil 20. The limiter 32 is used to limit the transmission of the drive signal of a preset frequency to the RF coil 20, for example, limiting the passage of a 128MHz RF signal. In this way, the RF signal frequency passing through each part of the RF coil 20 can be the same, and the transmission frequency of each loop LOOP can be the same, which is conducive to uniform distribution of the RF field. To save space, a slot for accommodating the limiter 32 is reserved on the cylinder 10.

[0057] Preferably, the power supply terminals of the power line 31 are connected to the end of the power feed port 200, and the power supply terminals of at least two of the feed assemblies 30 are converged to form a wiring harness group 310. The wiring harness group 310 is fixed to a preset position 110 at one end of the cylindrical body 10 along the axial direction. In other words, a portion of the power supply terminals are converged together, grounded, and connected to a switch unit to avoid signal phase deviation caused by inconsistent power line 31 lengths, which is beneficial for suppressing common-mode signals. Preferably, all power output terminals are converged into a wiring harness group 310.

[0058] For details, please refer to Figure 9 Combined with reference Figure 10 , Figure 10 yes Figure 3 In the enlarged view of the middle portion B, a plurality of first wiring grooves 11 corresponding to a plurality of feeding components 30 (power lines 31 ) are reserved on the cylinder 10 . Parts of the first wiring grooves 11 accommodating the power supply ends converge at one place to form a preset position 110 of the cylinder 10 . Figure 4 In the embodiment, the preset position 110 is located at the left end of the cylinder 10. It should be noted that the actual location of the preset position 110 on the cylinder 10 is not specifically limited in this embodiment, as long as it serves as a power supply terminal. Preferably, the preset position 110 is located at one axial end of the cylinder 10. Furthermore, it is understood that the first wiring trough 11 can arrange the power cables 31 in a regular manner, facilitate organization, and prevent the power cables 31 from becoming tangled and disordered.

[0059] In an exemplary embodiment, there are eight feeding assemblies 30, and the power supply ends of the eight feeding assemblies 30 are all gathered into a wire harness group 310 and fixed at the preset position 110 of the cylinder 10. The power line 31 is connected to the feeding port 200, which is actually a power line 31 connected to the end sub-unit 220 on a loop LOOP, which can be understood as a power line 31 corresponding to a loop LOOP. Figure 11 As shown, Figure 11 This is a schematic diagram of a switch unit according to an embodiment of the present invention. The power supply ends of eight power lines 31 converge into a wiring harness group 310 and then connect to a switch unit. The switch unit includes multiple switch devices (T / R switches) corresponding to the power lines 31. Figure 111 to 8 are shown in the figure, where number 1 corresponds to the first power line 31 in the wiring harness group 310, number 2 corresponds to the second power line 31 in the wiring harness group 310, ..., number 8 corresponds to the eighth power line 31 in the wiring harness group 310. In this embodiment, the switching device can be a single-pole double-throw switch. When the power supply end is connected to the radio frequency power amplifier (RFPA) by switching the switch, the radio frequency coil 20 can be put into a transmitting state at this time; when the power supply end is connected to the receiving channel (RX) by switching the switch, the radio frequency coil 20 can be put into a receiving state at this time. It should be noted that the figure only schematically illustrates the connection relationship between the first power line 31 corresponding to number 1 and the switching device, as well as the power amplifier (RFPA1) and the receiving channel (RX1). The connection relationship between the power lines 31 corresponding to other numbers and the switching devices can be derived accordingly, and this embodiment will not be described in detail.

[0060] In this embodiment, there can also be multiple wiring harness groups 310, and the cylinder 10 is reserved with the preset positions 110 corresponding to the multiple wiring harness groups 310. The number of power supply terminals in each wiring harness group 310 can be equal or unequal; the multiple preset positions 110 are arranged at intervals along the axial direction of the cylinder 10. Preferably, the multiple preset positions 110 are distributed at the same end of the cylinder 10 along the axial direction for easy organization. In an exemplary embodiment, there are two wiring harness groups 310, each wiring harness group 310 has four power supply terminals of the feeding components 30, and accordingly, there are two preset positions 110 on the cylinder 10. The two preset positions 110 can be set to be symmetrical about the central axis of the cylinder 10 along the radial direction of the cylinder 10, so that the two wiring harness groups 310 are symmetrically distributed.

[0061] Furthermore, the RF coil system also includes a power supply assembly, comprising a power supply line 41 connected to the RF coil 20, which transmits a DC power supply signal to the RF coil 20. The feed assembly 30 includes a power line 31 connected to the RF coil 20. The end of the power line 31 not connected to the RF coil 20 (i.e., the power supply end) and the end of the power line 41 not connected to the RF coil 20 are located on opposite sides of the cylindrical body 10 along its axis. Compared to the prior art in which the power supply end and the end of the power line 41 not connected to the RF coil 20 are located on the same side, this embodiment prevents interference between RF and DC signals. Furthermore, a second routing slot 12 for routing the power line 41 can be configured on the cylindrical body 10.

[0062] In one embodiment, the current flowing through the loop LOOP of the RF coil 20 is distributed in a discrete form, and the current corresponding to the nth LOOP is approximately:

[0063]

[0064] Among them, J leg (n) is the current in the nth loop; N is the total number of loops. For example, when N is 12, the loops 1 to 12 are counted clockwise. The currents in the 1st and 6th loops are the highest. By adjusting the corresponding power supply, the power supply line 41 can provide different current source signals.

[0065] According to another aspect of the present invention, a magnetic resonance imaging device is provided, comprising the radio frequency coil system described above. It will be appreciated that, because the magnetic resonance imaging device includes the radio frequency coil system described above, the device exhibits the beneficial effects of the radio frequency coil system. The operating principle and other structural components of the magnetic resonance imaging device will not be further described in this embodiment; those skilled in the art will be able to understand these principles based on existing knowledge.

[0066] In one embodiment, a magnetic resonance imaging device includes a control system and a radio frequency coil system. The control system may include a field-programmable gate array (FPGA) control unit, a digital-to-analog converter (DAC), a radio frequency amplifier, and a power divider connected in sequence. A radio frequency sequence transmitted by the FPGA control unit is sequentially converted into an analog signal by the DAC, amplified by the radio frequency amplifier, and then converted into a drive signal by the power divider and transmitted to multiple feeding ports 200 of the radio frequency coil 20, thereby driving the radio frequency coil 20 to generate a circularly polarized field.

[0067] In summary, the RF coil system and magnetic resonance imaging device provided by the present invention include: a cylindrical body; an RF coil disposed around the cylindrical body, the RF coil including multiple feed ports spaced apart along its circumference; and multiple feed assemblies disposed on the cylindrical body, each corresponding to each feed port. Each feed assembly is connected to the corresponding feed port to transmit a drive signal to the RF coil. Compared to the prior art, the present invention, by providing multiple feed ports and corresponding multiple feed assemblies, makes the RF field generated by the RF coil more uniformly distributed, thereby improving magnetic resonance imaging results.

[0068] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A radio frequency coil system, used in magnetic resonance imaging equipment, characterized in that: include: Cylinder; a radio frequency coil, which is arranged around the cylindrical body, and includes a plurality of feeding ports arranged at intervals along the circumference of the radio frequency coil; A plurality of feeding assemblies are provided on the cylindrical body, the feeding assemblies correspond to the feeding ports one by one, and the feeding assemblies are connected to the corresponding feeding ports; The radio frequency coil includes at least eight loops arranged along the circumference and a plurality of coupling assemblies arranged at intervals along the circumference of the cylinder, each loop includes a crosspiece and an end, and adjacent loops have a common crosspiece. The coupling assemblies are used to adjust the degree of coupling between adjacent loops; Each of the feeding ports corresponds to a loop, each of the feeding components is connected to a different power amplifier, and the amplitude and phase of the driving signal generated by each power amplifier are independently set.

2. The radio frequency coil system according to claim 1, wherein: The plurality of feeding assemblies are arranged at intervals along the circumference of the cylinder, and at least a portion of the feeding assemblies are arranged circumferentially.

3. The radio frequency coil system according to claim 1, wherein: The feeding assembly includes a power line and a wave limiter. One end of the power line is connected to the feeding port to transmit a driving signal. The wave limiter is used to limit the driving signal of a preset frequency to be transmitted to the radio frequency coil.

4. The radio frequency coil system according to claim 3, wherein: The power line is different from the end connected to the feeding port to lead out the power supply end, and the power supply ends of at least two feeding components converge to form a wiring harness group, and the wiring harness group is fixed at a preset position at one end of the cylinder along the axial direction.

5. The radio frequency coil system according to claim 4, wherein: The power supply ends of all the feeding components are gathered into one wiring harness group.

6. The radio frequency coil system according to claim 1, wherein: The RF coil system further includes a power supply assembly, which includes a power supply line connected to the RF coil; the feed assembly includes a power line connected to the RF coil; the end of the power line other than the end connected to the RF coil and the end of the power line other than the end connected to the RF coil are distributed on both sides of the cylinder along its own axis.

7. The radio frequency coil system according to claim 1, wherein: The radio frequency coil system further includes a plurality of tuning components; the adjustment ends of the plurality of tuning components are located on one side of the cylinder along the axial direction; and the adjustment ends of the plurality of coupling components are located on one side of the cylinder along the axial direction.

8. The radio frequency coil system according to claim 7, wherein: The tuning component includes a tuning rod and a tuning capacitor; the coupling component includes a coupling rod and a coupling capacitor.

9. The radio frequency coil system according to claim 8, wherein: The cylinder has a plurality of grooves, which are recessed inwardly along the radial direction of the cylinder. At least a first portion of the grooves is used to accommodate the tuning capacitor, and at least a second portion of the grooves is used to accommodate the coupling capacitor.

10. A magnetic resonance imaging device, characterized in that: The invention comprises the radio frequency coil system according to any one of claims 1 to 9.

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