CN115327457A

CN115327457A - Radio frequency coil system and magnetic resonance imaging equipment

Info

Publication number: CN115327457A
Application number: CN202110505951.4A
Authority: CN
Inventors: 徐烽; 罗威; 方福衣
Original assignee: Shanghai United Imaging Healthcare Co Ltd
Current assignee: Shanghai United Imaging Healthcare Co Ltd
Priority date: 2021-05-10
Filing date: 2021-05-10
Publication date: 2022-11-11

Abstract

The invention provides a radio frequency coil system applied to a magnetic resonance imaging device, which comprises: a barrel; the radio frequency coil is arranged on the barrel in an enclosing mode and comprises a plurality of feeding ports which are arranged at intervals along the circumferential direction of the radio frequency coil; the feeding components are arranged on the barrel body, correspond to the feeding ports one to one, and are connected with the corresponding feeding ports. Compared with the prior art, the invention has the advantages that the distribution of the radio frequency field generated by the radio frequency coil is more uniform by arranging the plurality of feed ports and the plurality of corresponding feed components, so that the effect of magnetic resonance imaging is better.

Description

Radio frequency coil system and magnetic resonance imaging equipment

Technical Field

The invention relates to the technical field of medical instruments, in particular to a radio frequency coil system and magnetic resonance imaging equipment.

Background

As shown in fig. 1, fig. 1 is a radio frequency coil system in the prior art, which includes a cylinder 01, a body radio frequency coil 02 surrounding the cylinder, and a feeding port 03 and a power supply port 04 both disposed on the cylinder, wherein the feeding port 03 generates a radio frequency signal and transmits the body radio frequency coil, and the power supply port 04 generates a direct current signal and transmits the direct current signal to the body radio frequency coil. In the prior art, two feed ports 03 are arranged on the cylinder, the two feed ports are generally symmetrical about the central axis of the cylinder 02 along the radial direction of the cylinder 02, and radio frequency fields generated by the two feed ports 03 are relatively unevenly distributed; two power lines of the two feed ports 03 are led out nearby without being converged together and grounded uniformly, so that phase deviation of radio-frequency signals is easily caused, and meanwhile, common-mode signals are not effectively inhibited; the power line of the feed port 03 and the power supply line of the power supply port are both outgoing lines at the same end along the axial direction of the cylinder 02 (in fig. 1, both outgoing lines are at the left end of the cylinder), although the power supply port is advantageous from the service point of magnetic resonance, there is a risk that the radio frequency signal and the direct current signal interfere with each other.

Disclosure of Invention

The invention aims to provide a radio frequency coil system and a magnetic resonance imaging device, which aim to solve the problem of non-uniform radio frequency field generated by the existing radio frequency coil system.

To solve the above technical problem, according to an aspect of the present invention, there is provided a radio frequency coil system, including:

a barrel;

the radio frequency coil is arranged on the barrel in an enclosing mode and comprises a plurality of feeding ports which are arranged at intervals along the circumferential direction of the radio frequency coil;

the feeding components are arranged on the barrel body, correspond to the feeding ports one to one, and are connected with the corresponding feeding ports.

Optionally, a plurality of the feeding components are arranged at intervals along the circumference of the cylinder, and at least a part of the feeding components are in a common circle Zhou Paibu.

Optionally, the feed assembly includes a power line and a wave limiter, and one end of the power line is connected to the feed port to transmit a driving signal; the wave limiter is used for limiting the transmission of the driving signal with preset frequency to the radio frequency coil.

Optionally, the power line is different from a power supply end led out from one end connected with the feed port, the power supply ends of at least two feed assemblies converge to form a wiring harness group, and the wiring harness group is fixed at a preset position of one end of the barrel body along the axial direction.

Optionally, the power supply terminals of all the feeding components are converged into one wire harness group.

Optionally, the radio frequency coil system further comprises a power supply assembly, wherein the power supply assembly comprises a power supply line connected with the radio frequency coil; the feed assembly comprises a power line connected with the radio frequency coil; the power line is different from and connects radio frequency coil's one end with the power supply line is different from and connects radio frequency coil's one end distribute in the barrel is along self axial both sides.

Optionally, the radio frequency coil system further includes a plurality of tuning assemblies and a plurality of tuning coupling assemblies arranged at intervals along the circumferential direction of the cylinder; the adjusting ends of the tuning assemblies are positioned on one side of the cylinder body along the axial direction; the adjusting ends of the adjusting and coupling assemblies are positioned on one side of the barrel body along the axial direction.

Optionally, the tuning component includes a tuning rod and a tuning capacitor; the coupling adjusting component comprises a coupling adjusting rod and a coupling adjusting capacitor.

Optionally, the cylinder has a plurality of grooves, the grooves are recessed inward along a radial direction of the cylinder, at least a first portion of the grooves are used for accommodating the tuning capacitor, and at least a second portion of the grooves are used for accommodating the tuning coupling capacitor.

Based on another aspect of the invention, the invention also provides a magnetic resonance imaging device comprising the radio frequency coil system as described above.

In summary, in the radio frequency coil system and the magnetic resonance imaging apparatus provided by the present invention, the radio frequency coil system includes: a cylinder body; the radio frequency coil is arranged on the barrel in an enclosing mode and comprises a plurality of feeding ports which are arranged at intervals along the circumferential direction of the radio frequency coil; the feeding components are arranged on the barrel body and correspond to the feeding ports one to one, and the feeding components are connected with the corresponding feeding ports so as to transmit driving signals to the radio frequency coil. Compared with the prior art, the invention has the advantages that the distribution of the radio frequency field generated by the radio frequency coil is more uniform by arranging the plurality of feed ports and the plurality of corresponding feed components, so that the effect of magnetic resonance imaging is better.

Drawings

It will be appreciated by those skilled in the art that the drawings are provided for a better understanding of the invention and do not constitute any limitation to the scope of the invention. Wherein:

FIG. 1 is a schematic diagram of a prior art radio frequency coil system;

FIGS. 2 and 3 are schematic diagrams of a radio frequency coil system in accordance with an embodiment of the present invention;

FIG. 4 is a schematic diagram of a radio frequency coil in accordance with one embodiment of the present invention;

FIG. 5 is an equivalent diagram of the radio frequency coil of FIG. 4;

FIG. 6 is an equivalent diagram of the loop of the radio frequency coil of one embodiment of the present invention;

fig. 7 and 8 are enlarged views of a portion a in fig. 3;

FIG. 9 is a schematic view of a cartridge according to an embodiment of the invention;

FIG. 10 is an enlarged view of portion B of FIG. 3;

fig. 11 is a schematic diagram of a switching unit according to an embodiment of the present invention. .

In the drawings:

01-barrel body; 02-radio frequency coil; 03-a feed port; 04-power supply port;

10-a cylinder body; 11-a first cabling channel; 110-preset position; 12-a second cabling channel; 13-a groove;

20-a radio frequency coil; 200-a feed port; 21-a rail portion; 210-rung sub-units; 22-end portion; 220-a terminal subunit; a LOOP-LOOP;

30-a feeding component; 31-a power line; 310-wire harness group; 32-a wave limiter; 41-supply line; 50-a tuning component; 51-a tuning rod; 52-tuning capacitance; 53-tuning the bushing; 54-a coupling capacitance; 60-preset fixed capacitance.

Detailed Description

To further clarify the objects, advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is to be noted that the drawings are in greatly simplified form and are not to scale, but are merely intended to facilitate and clarify the explanation of the embodiments of the present invention. Further, the structures illustrated in the drawings are often part of actual structures. In particular, the drawings may have different emphasis points and may sometimes be scaled differently.

As used in this application, the singular forms "a", "an" and "the" include plural referents, the term "or" is generally employed in a sense including "and/or," the terms "a" and "an" are generally employed in a sense including "at least one," the terms "at least two" are generally employed in a sense including "two or more," and the terms "first", "second" and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit to the number of technical features indicated. Thus, features defined as "first," "second," and "third" may explicitly or implicitly include one or at least two of the features unless the content clearly dictates otherwise.

The invention provides a radio frequency coil system and a magnetic resonance imaging device, which aim to solve the problem of non-uniform radio frequency field generated by the existing radio frequency coil system.

The following description refers to the accompanying drawings.

As shown in fig. 2 and 3, fig. 2 and 3 are schematic diagrams of a radio frequency coil system according to an embodiment of the present invention, and the embodiment provides a radio frequency coil system including: a cylinder 10; the radio frequency coil 20 surrounds the barrel 10, and the radio frequency coil 20 comprises a plurality of feed ports 200 which are arranged at intervals along the circumferential direction of the radio frequency coil 20; a plurality of feeding components 30 disposed on the barrel 10, wherein the feeding components 30 correspond to the feeding ports 200 one by one, and the feeding components 30 are connected to the corresponding feeding ports 200 to transmit driving signals (e.g., rf driving signals) to the rf coil 20. In this embodiment, the cylinder 10 is substantially annular and cylindrical, and the scanning cavity of the cylinder 10 is used for loading the examination object and performing scanning imaging under the relevant equipment of magnetic resonance imaging.

Optionally, the rf coil system may be connected to a control system, and the control system may include an FPGA (Field-Programmable Gate Array) control unit, a Digital-to-analog conversion unit (DAC), an rf amplifier and a power divider, which are connected in sequence, wherein a radio frequency sequence transmitted by the FPGA control unit is sequentially converted into an analog signal by the Digital-to-analog conversion unit, amplified by the rf amplifier, and then converted into a driving signal by the power divider, and sent to the plurality of feeding ports 200 of the rf coil 20, so as to drive the rf coil 20 to generate a circularly polarized Field.

The radio frequency coil 20 is a key component of the MRI apparatus, and the radio frequency coil 20 may have a transmitting function or both a transmitting function and a receiving function. The radio frequency coil 20 in this embodiment has both a transmitting function and a receiving function, specifically, when the radio frequency coil 20 is controlled by the switch to be in a transmitting state, a radio frequency pulse is transmitted to the inspection object to generate a radio frequency field, so that some atoms (such as hydrogen atoms) containing singular protons in the body of the inspection object absorb energy to generate resonance; when the radio frequency coil 20 is switched to a receiving state, an MR signal (similar to a radio wave) formed by atomic resonance in the body of the examination object is received.

Further, the radio frequency coil 20 of the present embodiment may be a body transmit coil and, further, may be a degenerate birdcage coil. According to the radio frequency coil system, by arranging the plurality of feeding ports 200 arranged at intervals along the circumferential direction of the radio frequency coil 20 and the plurality of corresponding feeding components 30, when the radio frequency coil 20 is in a transmitting state, a generated radio frequency field is more uniform than the radio frequency coil 20 in the prior art, so that the definition of magnetic resonance imaging is better, the imaging quality is higher, and further, the pathological reason of an examination object can be judged by an operator.

Further, as shown in fig. 4 and 5, fig. 4 is a schematic diagram of a radio frequency coil according to an embodiment of the present invention, fig. 5 is an equivalent diagram of the radio frequency coil in fig. 4, the radio frequency coil 20 includes a plurality of crosspieces 21 and two end portions 22, the crosspieces 21 are provided with transverse end antennas, the end portions 22 are provided with end ring antennas, the end portions 22 are provided at two ends of the crosspieces 21 and two end portions between two adjacent crosspieces 21, the crosspieces 21 are respectively connected to the end portions 22 at two ends thereof, the plurality of crosspieces 21 are arranged at intervals (preferably, at even intervals) in a circumferential direction of the radio frequency coil 20, and the crosspieces 21 extend in an axial direction of the radio frequency coil 20. The rung portion 21 includes a plurality of rung sub-units 210 sequentially arranged adjacently along the axial direction of the rf coil 20, two adjacent rung sub-units 210 are connected by a capacitor, generally, two adjacent rung sub-units 210 located at the middle position of the rung portion 21 are connected by a fixed capacitor, and two rung sub-units 210 on the rung portion 21 near the end portion 22 or the rung sub-units 210 on the rung portion 21 for connecting with the end portion 22 are connected by an adjustable capacitor (i.e., the capacitance value of the capacitor can be adjusted). So set up, can make the error of every fixed capacitor adjust through adjustable electric capacity to realize accurate transmission frequency calibration. Further, each end portion 22 includes a plurality of end sub-units 220, and the plurality of end sub-units 220 are arranged at intervals in the circumferential direction of the radio frequency coil 20 so as to form the end portion 22 in a ring shape.

In this embodiment, two adjacent crosspieces 21 and a plurality of end sub-units 220 located between the two crosspieces 21 form a LOOP, so that it is known that the radio frequency coil 20 includes a plurality of LOOP LOOPs arranged along the circumferential direction, and the number of LOOP LOOPs is equal to the number of crosspieces 21 of the radio frequency coil 20, and further known that the number of feed ports 200 in this embodiment is equal to the number of LOOP LOOPs, that is, one feed port 200 acts on one LOOP, and optionally, the position of the feed port 200 may be set on an end 22, for example, in this embodiment (see fig. 5), a plurality of feed ports 200 are set on the same end 22 at intervals along the circumferential direction of the radio frequency coil 20, that is, the feed ports 200 are located on the end sub-unit 220.

Further, two adjacent rung sub-units 210 may be connected by a fixed capacitor or an adjustable capacitor, and in the present embodiment, in consideration that when the radio frequency coil 20 is mounted on the barrel 10, the position accuracy between the LOOP LOOPs is different, and the fixed capacitors connected between the rung sub-units 210 have a deviation, the present embodiment is preferably configured that two adjacent rung sub-units 210 are connected by an adjustable capacitor, so as to adjust the resonant frequency of different LOOP LOOPs, and thus achieve precise resonant frequency adjustment of the radio frequency coil 20.

Further, referring to fig. 6, fig. 6 is an equivalent diagram of LOOP LOOPs of the rf coil 20 according to an embodiment of the invention, and fig. 6 exemplarily illustrates a current flow direction of one of the LOOP LOOPs. It should be noted that the current flow directions of the plurality of LOOP LOOPs may be the same as each other, or may be different from each other, depending on the magnitude and phase of the supply current of each LOOP, and those skilled in the art may configure the LOOP according to actual situations, and this embodiment is not described in detail.

In one embodiment, the current flowing through the LOOP of the rf coil 20 is distributed in a discrete manner, and the current corresponding to the nth LOOP is approximately:

wherein, J _leg (n) is the current on the first LOOP; n is the total number of LOOP. For example: when N is 12, 1 LOOP to 12 LOOP, count clockwise. The current is greatest at the 1 st LOOP and the 6 th LOOP. Correspondingly, different current source signals can be provided for different LOOPs. It will be understood, of course, that each of the feeding assemblies 30 may be connected to a different power amplifier, and the amplitude and phase of the driving signal generated by each power amplifier may also be independently set, i.e., the amplitude and phase of the driving signal for each LOOP may be independently set.

Based on the above principle, the present embodiment configures the rf coil system further includes a plurality of tuning assemblies 50 and a plurality of tuning coupling assemblies arranged at intervals along the circumferential direction of the cylinder 10; the tuning assemblies 50 are used for adjusting the resonant frequency of the radio frequency coil 20 to achieve accurate calibration of the transmitting frequency, and the adjusting ends of the tuning assemblies 50 are located at one side of the barrel 10 along the axial direction; the adjusting coupling component is used for adjusting LOOP coupling of the radio frequency coil 20, namely adjusting the coupling degree between adjacent LOOP LOOPs; the adjusting ends of the adjusting and coupling assemblies are located on one side of the cylinder 10 along the axial direction. Here, the adjusting end of the tuning assembly refers to a part of the tuning assembly for tuning by an operator; the adjusting end of the adjusting coupling component refers to a portion of the adjusting coupling component for an operator to adjust coupling (adjust coupling between LOOPs). The adjusting ends of the tuning assemblies 50 are located on one side of the cylinder 10 in the axial direction, and the adjusting ends of the tuning assemblies are located on one side of the cylinder 10 in the axial direction, including two cases: (1) The adjusting ends of the tuning assemblies 50 are located on one side of the cylinder 10 in the axial direction, and the adjusting ends of the tuning assemblies are located on the other side of the cylinder 10 in the axial direction, for example, the adjusting ends of the tuning assemblies 50 are located on the left side, and the adjusting ends of the tuning assemblies are located on the right side; (2) The adjustment ends of the tuning assemblies 50 and the adjustment ends of the tuning coupling assemblies are both located on one side of the barrel 10 in the axial direction, such as both the left side or the right side of the barrel 10. So configured, it is convenient for the operator to tune and/or tune the coupler uniformly on one side of the cylinder 10, and it is more convenient and faster to implement.

The tuning assembly 50 can adjust the error of the fixed capacitor to realize accurate calibration of the transmitting frequency, considering that each fixed capacitor has a certain error. Further, referring to fig. 7 and 8, fig. 7 and 8 are enlarged views of a portion a in fig. 3, the tuning assembly 5050 includes a tuning rod 51 and a tuning capacitor 52, the tuning capacitor 52 is disposed on the rf coil 20, and the tuning capacitors 52 of the 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 with the tuning capacitor 52, and the tuning rod 51 is used for rotating around the axial direction thereof so as to adjust the capacitance value of the tuning capacitor 52. Referring to fig. 7, after the tuning rod 51 rotates, the relative distance or the facing area of the metal sheet inside the tuning capacitor 52 is changed for the tuning capacitor 52 disposed in the crosspiece portion 21, so as to change the resistance value of the tuning capacitor 52, and further, to adjust the resonant frequency of the rf coil.

Referring to fig. 8, the adjustable coupling capacitor 54 is disposed on the end portion 22 for connecting a portion of two adjacent end sub-units 220, for example, in the adjacent three end sub-units 220, a first end sub-unit 220 and a second end sub-unit 220 may be connected through a predetermined fixed capacitor 60, and the second end sub-unit 220 and the third end sub-unit 220 are connected through the adjustable coupling capacitor 54. For the adjustable coupling capacitor 54 arranged in the end portion 22, after the adjustable coupling rod rotates, the relative distance or the facing area of the metal sheet in the adjustable coupling capacitor 54 is changed, so that the resistance value of the adjustable coupling capacitor 54 is changed, the decoupling between the adjacent LOOP LOOPs is realized, and the damage of the radio frequency coil 20 is avoided.

The tuning components comprise tuning rods and tuning capacitors, the tuning capacitors are arranged on the radio frequency coil 20, and the tuning capacitors of the tuning components 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 with the tuning capacitor, and the tuning rod is used for rotating around the axial direction of the tuning rod so as to adjust the capacitance value of the tuning capacitor. Specifically, the tuning capacitor is disposed (may be welded) on the rail 21 to connect two adjacent rail sub-units 210 near the end 22 on the rail 21, or to connect the end 22 and one rail sub-unit 210 of the rail 21 (the rail sub-unit 210 at one end of the rail 21, for example, may be the leftmost rail sub-unit 210). After the tuning rod rotates, the relative distance or the opposite area between the metal sheets in the tuning capacitor is changed, so that the capacitance value is changed, and the radio frequency emission frequency deviation caused by the physical error II of the fixed capacitor is corrected. It should be noted that the specific structure of the tuning assembly 50 is illustrated, and the specific structure of the tuning assembly is substantially the same as the tuning assembly 50, and is not illustrated here.

Furthermore, a tuning sleeve 53 may be disposed on the tuning rod 51, and a gap is left between the tuning sleeve 53 and the tuning capacitor 52 to expose a portion of the tuning rod 51. In fact, in the magnetic resonance apparatus, since the radio frequency coil 20 is installed inside the gradient coil, the capacitance of the tuning capacitor 52 can be changed only by screwing the elongated tuning rod 51, and the exposed portion of the tuning rod 51 can be screwed by a straight screwdriver. As previously described, the adjustment ends of the plurality of tuning assemblies 50 are located on one side of the barrel 10 in the axial direction, i.e., the portions of the tuning rods 51 of the plurality of tuning assemblies 50 exposed from the tuning bushings 53 are located on the same side of the barrel 10 for easy operation by the technician. Similarly, a coupler sleeve is disposed on the coupler rod, and the arrangement of the coupler rod and the coupler sleeve in the coupler assembly, and the screwing manner of the coupler rod can be configured correspondingly with reference to the tuning assembly 50, and will not be described herein.

For the multi-channel rf coil 20, the adjustment of the frequency and the adjustment of the coupling are very complicated, and the common adjustment method is to simplify the design by using the adjustable capacitors as described above, so as to facilitate the adjustment, i.e., the tuning capacitor 52 and the coupling capacitor 54 as described above. However, in the high-pass rf field, the tuning capacitor 52 and the tuning coupling capacitor 54, which are resistant to voltage, are large in size, and occupy a large space when disposed in the rf coil system. As shown in fig. 9, fig. 9 is a schematic diagram of a cylinder 10 according to an embodiment of the present invention, and in view of this, a plurality of grooves 13 are further disposed on the cylinder 10, the grooves 13 are recessed inward along a radial direction of the cylinder 10, at least a first portion of the grooves 13 are used for accommodating the tuning capacitor 52, and at least a second portion of the grooves 13 are used for accommodating the decoupling capacitor 54. In this way, the tuning capacitor 52 and the coupling capacitor 54 can be sunk in the barrel 10, and the space design is simplified. Preferably, there is a gap between the tuning capacitor 54 and the tuning capacitor 52 and the recess 13, that is, there is no contact with the recess 1323, which means that the tuning capacitor 52 and the tuning capacitor 54 are suspended in the recess 13, so that the risk of over-temperature of the inner wall of the barrel 10 caused by heat generated by the tuning capacitor 52 and the tuning capacitor 54 under high-power operation can be reduced, and negative effects on the inspection object can be avoided.

As a preferable solution of this embodiment, please refer to fig. 2 and fig. 3, a plurality of feeding assemblies 30 are arranged at intervals along the circumference of the barrel 10, preferably, distributed at equal intervals along the circumference; at least a portion of the feeding members 30 are arranged in a common circumferential manner, and preferably, all the feeding members 30 are arranged in a common circumferential manner, so that the structural arrangement and the regular distribution of the whole device are facilitated. It should be noted that whether the feed assembly 30 is circumferentially concentric does not affect the uniformity of the rf field.

In other embodiments, at least a portion of the feeding elements 30 are spaced along the axial direction of the barrel 10, i.e. at least a portion of the feeding elements 30 are not concentric Zhou Paibu, such as one feeding element 30 moving a distance to the left of the barrel 10 and another feeding element 30 moving a distance to the right.

Further, the feeding assembly 30 includes a power line 31 and a wave limiter 32, wherein one end of the power line 31 is connected to the feeding port 200 to transmit the driving signal, i.e., is connected to the end subunit 220 of the end 22 of the radio frequency coil 20; the limiter 32 is configured to limit the transmission of the driving signal with a predetermined frequency to the radio frequency coil 20, such as a radio frequency signal with a frequency of 128 MHz. Thus, the frequencies of the radio frequency signals passing through the parts of the radio frequency coil 20 are the same, and the transmitting frequencies of the LOOPs LOOP are the same, which is beneficial to the uniform distribution of the radio frequency field. In order to save space, a groove for accommodating the wave limiter 32 is reserved on the cylinder 10.

Preferably, the power line 31 is led out from an end different from the end connected to the feeding port 200, the power supply ends of at least two feeding assemblies 30 converge to form a wiring harness group 310, and the wiring harness group 310 is fixed at the preset position 110 at one end of the barrel 10 along the axial direction. A part of power supply ends are gathered together and then are connected into a switch unit after being uniformly grounded, so that signal phase deviation caused by inconsistent line length of the power line 31 is avoided, and the suppression of common-mode signals is facilitated. Preferably, all power outlets are grouped into a bundle 310.

Specifically, please refer to fig. 9 in combination with fig. 10, fig. 10 is an enlarged view of a portion B in fig. 3, a plurality of first wire routing grooves 11 corresponding to the plurality of power feeding components 30 (power lines 31) one to one are reserved on the barrel 10, and portions of the first wire routing grooves 11, which accommodate power supply terminals, converge at a preset position 110 forming the barrel 10. In fig. 4, the preset position 110 is located at the left end of the cylinder 10. It should be noted that the actual position of the preset position 110 on the cylinder 10 is not particularly limited in this embodiment, as long as the preset position serves as a power supply end for collecting power, and preferably, the preset position 110 is located at one end of the cylinder 10 along the axial direction. In addition, it can be understood that the first wiring groove 11 can arrange the power lines 31 regularly, so that the arrangement is convenient, and the mutual winding and disorder of the power lines 31 are avoided.

In an exemplary embodiment, the present embodiment exemplarily has eight feeding assemblies 30, and the power supply ends of the eight feeding assemblies 30 are all converged into one wire harness group 310 and fixed at the preset position 110 of the barrel 10. Power line 31 is connected to power supply port 200, and in fact, one power line 31 is connected to terminal subunit 220 on one LOOP, that is, it is understood that one power line 31 corresponds to one LOOP. As shown in fig. 11, fig. 11 is a schematic diagram of a Switch unit according to an embodiment of the present invention, power supply terminals of eight power lines 31 converge after one harness group 310, and the Switch unit is connected to the Switch unit, and the Switch unit includes a plurality of Switch devices (T/R Switch) corresponding to the power lines 31, and fig. 11 exemplifies numbers 1 to 8, where the number 1 corresponds to a first power line 31 in the harness group 310, the number 2 corresponds to a second power line 31, … … in the harness group 310, and the number 8 corresponds to an eighth power line 31 in the harness group 310. In this embodiment, the switch device may be a single-pole double-throw switch, and when the power supply terminal is connected to a Radio Frequency Power Amplifier (RFPA) by switching the switch, the radio frequency coil 20 may be in a transmitting state at this time; when the power supply terminal is connected to the receiving channel (RX) by switching the switch, the rf coil 20 is in a receiving state. It should be noted that, in the figure, only the connection relationship between the first power line 31 corresponding to the number 1 and the switching device, and between the power amplifier (RFPA 1) and the receiving channel (RX 1) is schematically indicated, and the connection between the power lines 31 corresponding to other numbers and the switching device can be obtained accordingly, and this embodiment is not described in detail.

In this embodiment, a plurality of wire harness groups 310 may also be provided, and the preset positions 110 corresponding to the plurality of wire harness groups 310 one to one are reserved on the cylinder 10. The number of power supply terminals in each harness group 310 may or may not be equal; the preset positions 110 are arranged at intervals along the axial direction of the cylinder 10, and preferably, the preset positions 110 are distributed at the same axial end of the cylinder 10, so that the arrangement is convenient. In an exemplary embodiment, there are two wire harness sets 310, each wire harness set 310 has power supply ends of four power feeding assemblies 30, and accordingly, there are two preset positions 110 on the barrel 10, and the two preset positions 110 may be disposed symmetrically about the central axis of the barrel 10 in the radial direction of the barrel 10, so that the two wire harness sets 310 are symmetrically distributed.

Further, the radio frequency coil system further comprises a power supply assembly, the power supply assembly comprises a power supply line 41 connected to the radio frequency coil 20, the power supply line 41 transmits a dc power supply signal to the radio frequency coil 20; the feeding component 30 comprises a power line 31 connected with the radio frequency coil 20; the power lines 31 are distributed on both sides of the cylinder 10 along the axial direction thereof, unlike one end (i.e. power supply end) connected to the rf coil 20 and one end of the power supply lines 41 connected to the rf coil 20. Compared with the prior art in which the power supply terminal and the power supply line 41 are located on the same side as the terminal connected to the rf coil 20, the present embodiment can avoid the mutual interference between the rf signal and the dc signal. In addition, a second wire slot 12 for the power supply wire 41 to run can be disposed on the barrel 10.

In one embodiment, the LOOP of the rf coil 20 has a discrete distribution of current flowing therethrough, with the current corresponding to the nth LOOP approximating:

wherein, J _leg (n) is the current on the first LOOP; n is the total number of LOOP. For example: when N is 12, 1 LOOP to 12 LOOP, count clockwise. The current is greatest at the 1 st LOOP and the 6 th LOOP. The supply line 41 can provide different current source signals by adjusting the corresponding power supply.

Based on another aspect of the invention, the invention also provides a magnetic resonance imaging device comprising the radio frequency coil system as described above. It is understood that the magnetic resonance imaging apparatus has the advantages of the radio frequency coil system, since the magnetic resonance imaging apparatus includes the radio frequency coil system, the working principle and other structural components of the magnetic resonance imaging apparatus will not be explained again, and those skilled in the art can understand the present invention according to the prior art.

In an embodiment, the magnetic resonance imaging apparatus includes a control system and a radio frequency coil system, the control system may include an FPGA (Field-Programmable Gate Array) control unit, a Digital-to-analog conversion unit (DAC), a radio frequency amplifier and a power divider, which are connected in sequence, wherein a radio frequency sequence transmitted by the FPGA control unit is sequentially converted into an analog signal by the Digital-to-analog conversion unit, amplified by the radio frequency amplifier, and then converted into a driving signal by the power divider, and sent to the plurality of feeding ports 200 of the radio frequency coil 20, so as to drive the radio frequency coil 20 to generate a circularly polarized Field.

In summary, in the radio frequency coil system and the magnetic resonance imaging apparatus provided by the present invention, the radio frequency coil system includes: a cylinder body; the radio frequency coil is arranged on the barrel in an enclosing mode and comprises a plurality of feeding ports which are arranged at intervals along the circumferential direction of the radio frequency coil; the feed components are arranged on the barrel body, correspond to the feed ports one by one and are connected with the corresponding feed ports so as to transmit driving signals to the radio frequency coil. Compared with the prior art, the magnetic resonance imaging device has the advantages that the radio-frequency field generated by the radio-frequency coil is distributed more uniformly by arranging the plurality of feed ports and the plurality of corresponding feed assemblies, so that the magnetic resonance imaging effect is better.

The above description is only for the purpose of describing the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention, and any variations and modifications made by those skilled in the art based on the above disclosure are within the scope of the appended claims.

Claims

1. A radio frequency coil system for use in a magnetic resonance imaging apparatus, comprising:

a cylinder body;

2. The radio frequency coil system of claim 1, wherein a plurality of the feed assemblies are arranged at intervals along a circumference of the cylinder, at least a portion of the feed assemblies being co-circular Zhou Paibu.

3. The radio frequency coil system as set forth in claim 1, wherein the feed assembly includes a power line and a limiter, one end of the power line being connected to the feed port to transmit a driving signal; the wave limiter is used for limiting the transmission of the driving signal with preset frequency to the radio frequency coil.

4. The radio-frequency coil system of claim 3, wherein the power line has a power supply end led out from an end different from the end connected to the feed port, the power supply ends of at least two of the feed assemblies converge to form a wire bundle group, and the wire bundle group is fixed at a predetermined position at one end of the barrel in the axial direction.

5. The radio frequency coil system of claim 4, wherein the power supply terminals of all the feed assemblies are converged into one of the wire bundle groups.

6. The radio frequency coil system of claim 1, further comprising a power supply assembly including a power supply line connected to the radio frequency coil; the feed assembly comprises a power line connected with the radio frequency coil; the power line is different from and connects radio frequency coil's one end with the power supply line is different from and connects radio frequency coil's one end distribute in the barrel is along self axial both sides.

7. The radio frequency coil system of claim 1, further comprising a plurality of tuning assemblies and a plurality of tuning coupling assemblies spaced circumferentially along the barrel; the adjusting ends of the tuning assemblies are positioned on one side of the cylinder body along the axial direction; the adjusting ends of the adjusting and coupling assemblies are positioned on one side of the cylinder body along the axial direction.

8. The radio frequency coil system of claim 7, wherein the tuning assembly includes a tuning rod and a tuning capacitor; the coupling adjusting component comprises a coupling adjusting rod and a coupling adjusting capacitor.

9. The radio frequency coil system as set forth in claim 8, wherein the cylinder has a plurality of grooves recessed radially inward of the cylinder, at least a first portion of the grooves being configured to receive the tuning capacitor and at least a second portion of the grooves being configured to receive the tuning capacitor.

10. A magnetic resonance imaging apparatus, characterized in comprising a radio frequency coil system as claimed in any one of claims 1 to 9.