Trap filters, local coils and MRI equipment

Abstract

The present application requests protection of a trap, a local coil, and a nuclear magnetic resonance device. The trap includes a trap body and a radio frequency cable. The trap body includes a tuning capacitor and a cable. The cable is electrically connected to the tuning capacitor in parallel, and a parallel resonance is formed between the cable and the tuning capacitor. The radio frequency cable is at least partially arranged in a spiral manner in the area where the trap body is located, and mutual inductance can be formed between the radio frequency cables, so that when the trap is working, a high impedance can be formed on the radio frequency cable by coupling to suppress the common mode current on the radio frequency cable. In this process, the trap is not affected by the volume of the radio frequency cable, so that the overall volume of the trap can be designed to be smaller, and the miniaturization of the overall structure of the trap is achieved. Therefore, the trap has the advantages of small size, light weight, and easy debugging and maintenance.

Description

Technical Field

[0001] The utility model belongs to the technical field related to nuclear magnetic resonance, and particularly relates to a wave trap, a local coil and nuclear magnetic resonance equipment. Background Art

[0002] During MRI scanning, the transmission power of the built-in volume transmission coil will generate a large common-mode current on the RF cable of the local coil, which seriously affects the B1 field of the local coil and thus the imaging quality. Therefore, in order to suppress this common-mode current, a notch filter needs to be designed on the RF cable of the local coil. However, in actual applications, RF cables are often switched, and the frequency of the notch filter will shift after being connected to other cables, resulting in repeated debugging, which brings many challenges to the design of the notch filter.

[0003] At present, the existing traps are mainly divided into two categories. The first type of trap is to wind the RF cable into a spiral shape, put a shielding cover on the outside, one end of the shielding cover is directly welded to the RF cable, and the other end is connected through a tuning capacitor. Due to the large inductance value, this type of trap has a good effect of suppressing common-mode current and generates less heat. However, the disadvantages of this type of trap are large size and heavy weight, and it increases the loss of the internal RF cable and affects the total phase distance. As the RF cable becomes thicker, the diameter of the spiral winding on the RF cable is also getting larger, which is unbearable. The second type of trap is to set the trap independently of the RF cable, and specifically install the tuning capacitor detachably at the end of the RF cable. The above trap can be easily installed on any RF cable and will not affect any coil parameters on the RF cable. However, the disadvantages are small inductance, severe heat generation, and the effect of suppressing common-mode current is affected by the outer diameter. The larger the outer diameter, the better the effect. Therefore, in order to obtain a good common-mode suppression effect, the size of the trap is still large and the weight becomes heavier. Therefore, it is particularly important to provide a notch filter with a new structure and a small size. Utility Model Content

[0004] In view of this, it is necessary to provide a trap filter, a local coil and a nuclear magnetic resonance device for solving the above technical problems.

[0005] A notch filter, the notch filter comprising:

[0006] The trap body includes a tuning capacitor and a cable, wherein the cable is electrically connected to the tuning capacitor in parallel;

[0007] The radio frequency cable is at least partially arranged in a spiral manner in the area where the wave trap body is located, and mutual inductance can be formed between the radio frequency cable and the cable.

[0008] It can be understood that by utilizing the parallel resonance formed by the parallel connection between the cable and the tuning capacitor, and the mutual inductance formed between the RF cable and the cable, the wave trap can form a high impedance on the RF cable by coupling when working, so as to suppress the common mode current on the RF cable. In this process, it is not affected by the volume of the RF cable, so that the overall volume of the wave trap can be designed to be smaller, and the overall structure of the wave trap can be miniaturized. Therefore, the wave trap has the advantages of small volume, light weight, and easy debugging and maintenance. In one embodiment, the RF cable extends along the first direction and passes through the wave trap body;

[0009] The radio frequency cable includes a plurality of radio frequency lines, the plurality of radio frequency lines are independently arranged, and each of the radio frequency lines is respectively wound around the wave trap body in the first direction.

[0010] It can be understood that since the diameter of the RF line is smaller than the diameter of the RF cable, the bending radius of the RF line when it is wound on the trap body is smaller, which can meet the use requirements of winding the RF cable on a small-volume trap body; in addition, since the RF line is wound onto the trap body along the first direction, this can avoid overlapping of multiple RF lines, which has the effect of further reducing the overall volume of the trap.

[0011] In one embodiment, the wave trap further comprises a shielding sleeve, wherein a shielding chamber is formed inwardly of the shielding sleeve;

[0012] Wherein, the cable is arranged in the shielding chamber.

[0013] It is understandable that the shielding chamber formed by the shielding sleeve is used to shield the cable, so as to prevent the internal magnetic field from affecting the external radio frequency field when the trap is working.

[0014] In one of the embodiments, the wave trap body further includes a wave trap bracket, and the cable is installed on the wave trap bracket;

[0015] The wave trap support can support the portion of the radio frequency cable located within the area where the wave trap body is located.

[0016] It can be understood that the wave trap support is used to support the cable and the radio frequency cable, so as to ensure that mutual inductance can be formed between the cable and the radio frequency cable.

[0017] In one embodiment, the cable comprises a spiral segment and a straight segment connected to each other, the spiral segment is wound around the wave trap bracket in a spiral manner, and the straight segment is arranged through the wave trap bracket;

[0018] Wherein, the spiral segment and the straight segment are electrically connected to the tuning capacitor respectively.

[0019] It can be understood that by utilizing the structural characteristics of the spiral section on the cable, the length of the cable when assembled on the wave trap bracket can be increased to meet the use requirements of suppressing common mode current on the radio frequency cable.

[0020] In one embodiment, the radio frequency cable has a spiral portion, and the spiral portion is wound on the wave trap support in a spiral manner;

[0021] Wherein, the spiral portion is arranged on the periphery of the spiral segment.

[0022] In one embodiment, the cable is arranged inside the wave trap bracket in a serpentine manner along a first direction.

[0023] It is understandable that the serpentine arrangement of the cables can increase the length of the cables when assembled on the wave trap bracket to meet the requirements of suppressing common mode current on the RF cables.

[0024] In one embodiment, the radio frequency cable includes a plurality of radio frequency lines, and the plurality of radio frequency lines are independently arranged;

[0025] A portion of at least one of the radio frequency lines is wound around the wave trap support in a spiral manner, and at least one of the radio frequency lines extends along a first direction and passes through the wave trap support.

[0026] The present application also claims protection for a local coil, comprising the above-mentioned trap filter.

[0027] The present application also seeks to protect a nuclear magnetic resonance device, comprising the local coil described above.

[0028] Due to the application of the above technical solution, the utility model has the following advantages compared with the prior art:

[0029] The trap, local coil and nuclear magnetic resonance equipment for which protection is sought in the present application utilize the parallel resonance formed by the parallel connection between the cable and the tuning capacitor, and the mutual inductance formed between the radio frequency cables, so that the trap can form a high impedance on the radio frequency cable by coupling when working, so as to suppress the common mode current on the radio frequency cable. In this process, the overall volume of the trap can be designed to be smaller, and the overall structure of the trap can be miniaturized. Therefore, the trap has the advantages of small size, light weight, and easy debugging and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A schematic diagram of the structure of a trap provided in some embodiments of the present application.

[0032] Figure 2 A schematic diagram of the structure of a wave trap bracket provided in some embodiments of the present application.

[0033] Figure 3 A schematic diagram of the structure of a trap provided in some embodiments of the present application.

[0034] Figure 4 A schematic diagram of the structure of a trap provided in some embodiments of the present application.

[0035] Figure 5 A schematic structural diagram of a wave trap body provided in some embodiments.

[0036] Figure numerals: 100, wave trap; 10, wave trap body; 11, tuning capacitor; 12, cable; 121, spiral section; 122, straight section; 13, wave trap bracket; 131, spiral groove; 132, outer cylinder wall; 133, center hole; 20, RF cable; 21, spiral part; 201, RF line; 30, shielding sleeve; 31, shielding chamber. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0038] It should be noted that when an element is referred to as being "provided on" another element, it may be directly provided on the other element or there may be a central element. When an element is considered to be "provided on" another element, it may be directly provided on the other element or there may be a central element at the same time. When an element is considered to be "fixed to" another element, it may be directly fixed to the other element or there may be a central element at the same time.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0040] like Figure 1 As shown, a wave trap 100 provided in an embodiment of the present application includes a wave trap body 10 and a radio frequency cable 20. The wave trap body 10 includes a tuning capacitor 11 and a cable 12. The cable 12 is electrically connected to the tuning capacitor 11 in parallel so that a parallel resonance is formed between the cable 12 and the tuning capacitor 11. The radio frequency cable 20 is at least partially arranged in a spiral manner in the area where the wave trap body 10 is located, and a mutual inductance can be formed between the radio frequency cable 20 and the cable 12. Here, the tuning capacitor 11 is configured as a ceramic capacitor or a distributed capacitor, and the cable 12 is a DC line.

[0041] It can be understood that since the cable 12 and the tuning capacitor 11 are connected in parallel to form a parallel resonance, mutual inductance is formed between the RF cable 20 and the cable 12, so that the trap 100 can form a high impedance on the RF cable 20 by coupling when working, so as to suppress the common mode current on the RF cable 20. In this process, it is not affected by the volume of the RF cable 20, so that the overall volume of the trap 100 can be designed to be smaller, and the miniaturization of the overall structure of the trap 100 is realized. Therefore, the trap 100 has the advantages of small size, light weight, and easy debugging and maintenance.

[0042] like Figure 2 , Figure 4 and Figure 5 As shown, in some embodiments, the wave trap body 10 further includes a wave trap bracket 13, and the wave trap bracket 13 can carry the portion of the RF cable 20 located in the area where the wave trap body 10 is located; and the cable 12 is installed on the wave trap bracket 13. In other words, the wave trap 100 can use the wave trap bracket 13 as an installation basis to carry the cable 12 and the portion of the RF cable 20 located in the area where the wave trap body 10 is located, so that the distance between the cable 12 and the corresponding portion of the RF cable 20 can be close enough, and it is ensured that the cable 12 and the RF cable 20 in the wave trap 100 can form a mutual inductance to suppress the common mode current on the RF cable 20.

[0043] like Figure 1 , Figure 3As shown, in some embodiments, the cable 12 includes a spiral segment 121 and a straight segment 122 connected to each other, and the spiral segment 121 and the straight segment 122 are respectively electrically connected to the tuning capacitor 11, and a parallel connection is achieved between the cable 12 and the tuning capacitor 11. Here, one end of the spiral segment 121 away from the straight segment 122 is electrically connected to one end of the tuning capacitor 11, and one end of the straight segment 122 away from the spiral segment 121 is electrically connected to the other end of the tuning capacitor 11.

[0044] In some embodiments, the spiral segment 121 is wound around the wave trap bracket 13 in a spiral manner, and the straight segment 122 is set through the wave trap bracket 13 to realize the assembly connection of the cable 12 on the wave trap bracket 13, that is, the cable 12 is partially installed in the wave trap bracket 13. In this way, the structural characteristics of the spiral segment 121 can be used to increase the length of the cable 12 when assembled on the wave trap bracket 13 to meet the use requirements of suppressing the common mode current on the RF cable 20. Here, the wave trap bracket 13 is configured as a spiral tube structure, and the straight segment 122 on the cable 12 can be set through the center hole 133 on the wave trap bracket 13.

[0045] like Figure 1 , Figure 2 As shown, in some embodiments, the RF cable 20 has a spiral portion 21, and the spiral portion 21 is wound on the wave trap bracket 13 in a spiral manner. Here, the spiral portion 21 of the RF cable 20 is arranged on the periphery of the spiral section 121 on the cable 12. For this purpose, a spiral groove 131 can be opened on the wave trap bracket 13, and the spiral section 121 of the cable 12 is arranged in the spiral groove 131 of the wave trap bracket 13, and the spiral portion 21 of the RF cable 20 is wound on the spiral outer cylinder wall 132 of the wave trap bracket 13.

[0046] like Figure 4 , Figure 5 As shown, in some embodiments, the cable 12 is arranged in a serpentine manner along a first direction inside the wave trap bracket 13, that is, the cable 12 is assembled as a whole into the inside of the wave trap bracket 13. In this way, by utilizing the serpentine arrangement characteristics of the cable 12, the length of the cable 12 when assembled in the wave trap bracket 13 can be increased to meet the use requirements of suppressing the common mode current on the RF cable 20. Here, the wave trap bracket 13 can specifically be a dielectric board of a PCB board, and the material of the dielectric board can be configured as ceramic or ice stone; and the above-mentioned cable 12 is arranged in a serpentine manner, specifically referring to that the cable 12 bends back and forth along the width direction of the wave trap bracket 13 in a serpentine shape.

[0047] like Figure 1 , Figure 4As shown, in some embodiments, the RF cable 20 extends along the first direction and is arranged through the wave trap body 10; wherein the RF cable 20 includes a plurality of RF lines 201, the plurality of RF lines 201 are arranged independently of each other, and each RF line 201 is respectively wound around the wave trap body 10 in the first direction. That is to say, in this embodiment, the plurality of RF lines 201 constituting the RF cable 20 are disassembled, and the plurality of RF lines 201 are sequentially wound around the wave trap body 10 along the first direction. In this process, since the diameter of the RF line 201 is smaller than the diameter of the RF cable 20, the bending radius of the RF line 201 when it is wound around the wave trap body 10 is smaller, which can meet the use requirement of the RF cable 20 for winding around the small volume wave trap body 10; in addition, since the RF line 201 is wound around the wave trap body 10 along the first direction, it can avoid the plurality of RF lines 201 from being stacked in the vertical direction of the first direction, which has the effect of further reducing the overall volume of the wave trap 100.

[0048] like Figure 4 As shown, in some embodiments, a portion of at least one RF line 201 among the plurality of RF lines 201 is spirally wound on the wave trap bracket 13, and at least one RF line 201 extends along the first direction and is disposed through the wave trap bracket 13. Here, the number of RF lines 201 spirally wound on the wave trap body 10 on the RF cable 20 is one, and the number of RF lines 201 extending along the first direction and passing through the wave trap bracket 13 is also one.

[0049] like Figure 3 As shown, in some embodiments, the wave trap 100 further includes a shielding sleeve 30, the shielding sleeve 30 is formed with a shielding chamber 31 inwardly, and the cable 12 is arranged in the shielding chamber 31. In other words, the wave trap 100 can be shielded by the shielding sleeve 30, so that when the wave trap 100 is applied to the local coil, the internal magnetic field of the wave trap 100 can be prevented from affecting the radio frequency field of the local coil when the wave trap 100 is working.

[0050] The present application also provides a local coil, comprising the above-mentioned trap filter 100.

[0051] The present application also provides a nuclear magnetic resonance device, comprising the local coil described above.

[0052] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, appropriate changes and modifications to the above embodiments are within the scope of protection required by the present invention.

Claims

1. A notch filter, characterized in that: The notch filter (100) comprises: A wave trap body (10) comprises a tuning capacitor (11) and a cable (12), wherein the cable (12) is electrically connected to the tuning capacitor (11) in parallel; The radio frequency cable (20) is at least partially arranged in a spiral manner in the area where the wave trap body (10) is located, and mutual inductance can be formed between the radio frequency cable (20) and the cable (12).

2. The wave trap according to claim 1, characterized in that: The radio frequency cable (20) extends along a first direction and is arranged passing through the wave trap body (10); The radio frequency cable (20) comprises a plurality of radio frequency lines (201), the plurality of radio frequency lines (201) are independently arranged, and each radio frequency line (201) is respectively wound around the wave trap body (10) in the first direction.

3. The wave trap according to claim 1, characterized in that: The wave trap (100) further comprises a shielding sleeve (30), wherein the shielding sleeve (30) is provided with a shielding chamber (31) formed inwardly; Wherein, the cable (12) is arranged in the shielding chamber (31).

4. The wave trap according to claim 1, characterized in that: The wave trap body (10) further comprises a wave trap bracket (13), and the cable (12) is mounted on the wave trap bracket (13); The wave trap support (13) is capable of supporting a portion of the radio frequency cable (20) located within the area where the wave trap body (10) is located.

5. The wave trap according to claim 4, characterized in that: The cable (12) comprises a spiral segment (121) and a straight segment (122) connected to each other, the spiral segment (121) is wound around the wave trap bracket (13) in a spiral manner, and the straight segment (122) is arranged to penetrate the wave trap bracket (13); The spiral segment (121) and the straight segment (122) are respectively electrically connected to the tuning capacitor (11).

6. The wave trap according to claim 5, characterized in that: The radio frequency cable (20) has a spiral portion (21), and the spiral portion (21) is wound on the wave trap support (13) in a spiral manner; Wherein, the spiral portion (21) is arranged on the periphery of the spiral section (121).

7. The wave trap according to claim 4, characterized in that: The cable (12) is arranged inside the wave trap bracket (13) in a serpentine manner along a first direction.

8. The wave trap according to claim 7, characterized in that: The radio frequency cable (20) comprises a plurality of radio frequency lines (201), and the plurality of radio frequency lines (201) are independently arranged. A portion of at least one of the radio frequency lines (201) is wound around the wave trap support (13) in a spiral manner, and at least one of the radio frequency lines (201) extends along a first direction and passes through the wave trap support (13).

9. A local coil, characterized in that: The invention comprises the trap filter (100) as claimed in any one of claims 1 to 8.

10. A nuclear magnetic resonance device, characterized in that: Comprising the local coil according to claim 9.

Images