Magnetic resonance system anti-interference device and magnetic resonance system

Abstract

The embodiment of the application discloses a magnetic resonance system anti-interference device and a magnetic resonance system. The device comprises a first PIN diode and a second PIN diode, wherein: the positive electrode of the first PIN diode and the negative electrode of the second PIN diode are connected to form a first pair of external connection ends; the negative electrode of the first PIN diode and the positive electrode of the second PIN diode are connected to form a second pair of external connection ends; the first pair of external connection ends are connected with the output end of the radio frequency power amplifier of the magnetic resonance system through a cable, the second pair of external connection ends are connected with the radio frequency system in the magnet room of the magnetic resonance system through a cable, and the magnetic resonance system anti-interference device is located outside the magnet room. The embodiment of the application suppresses the entry of external interference signals into the magnet room through the cable between the radio frequency power amplifier and the radio frequency system in the magnetic resonance receiving stage, and improves the anti-interference ability of the magnetic resonance system.

Description

Technical Field

[0001] This invention relates to the field of MRI (Magnetic Resonance Imaging) technology, and in particular to anti-interference devices for magnetic resonance systems and magnetic resonance systems. Background Technology

[0002] In order to receive weak human resonance signals and maximize the dynamic range of reception, the receiving system of magnetic resonance imaging (MRI) equipment is designed to have very high sensitivity, which places high demands on the system's ability to resist external interference.

[0003] Figure 1 A typical framework diagram of a magnetic resonance imaging (MRI) system is given. External interference signals enter the MRI system via two paths: 1. External interference signal 11 passes through the external space, through the shielding chamber 100, and enters the magnet chamber 200, where it is received by the radio frequency system 201; 2. External interference signal 12 first couples through space onto the signals on cables 101, 102, and 103, then enters the magnet chamber 200, where the signals radiate and are received by the radio frequency system 201. If these interference signals 11 and 12 are applied within the frequency range of MRI imaging, they will manifest as artifacts on the MRI image, thus affecting the diagnosis.

[0004] To improve the anti-interference capability of magnetic resonance imaging (MRI) systems, the following are some of the commonly used methods:

[0005] 1. For interference path one, improve the shielding performance of shielded room 100 as much as possible. Currently, the overall performance of good shielded rooms can reach more than 90dB.

[0006] Second, for interference path two, signals entering or exiting the shielding chamber are filtered to improve the cable's anti-interference capability, such as... Figure 1 As shown, a first filter 600 is connected in series on the cable 101 between the gradient amplifier 300 and the gradient system 202 inside the magnet 200, and located outside the magnet 200. A second filter 700 is connected in series on the cable 102 between the external power supply 400 and the internal power supply 203 inside the magnet 200, and located outside the magnet 200. These two filters 600 and 700 are typically designed to have the largest possible attenuation within the frequency band of the magnetic resonance signal and to exhibit low loss within the signal frequency band in which the filter operates.

[0007] However, for certain specific cables, such as Figure 1The cable 103, which connects to the output of the RF power amplifier 500, cannot use a filter solution because its operating frequency band is at the magnetic resonance frequency. Currently, cables with better shielding performance are usually used to reduce the coupling and re-radiation of interference signals. However, such high-shielding cables are usually very rigid, have low reliability, and their shielding performance will be greatly reduced after repeated bending. Summary of the Invention

[0008] In view of this, the present invention provides both an anti-interference device for a magnetic resonance system and a magnetic resonance system to improve the anti-interference capability of the magnetic resonance system.

[0009] A first aspect provides an anti-interference device for a magnetic resonance system, the device comprising: a first PIN diode and a second PIN diode, wherein:

[0010] The positive terminal of the first PIN diode and the negative terminal of the second PIN diode are connected to form the first external connection terminal;

[0011] The negative terminal of the first PIN diode and the positive terminal of the second PIN diode are connected to form the second external connection terminal;

[0012] The first external connection terminal is connected to the output terminal of the radio frequency power amplifier of the magnetic resonance system via a cable, and the second external connection terminal is connected to the radio frequency system inside the magnet compartment of the magnetic resonance system via a cable, and the anti-interference device of the magnetic resonance system is located outside the magnet compartment.

[0013] When in the magnetic resonance excitation stage, the RF power amplifier amplifies the input RF signal and outputs the amplified RF signal. The positive voltage signal of the amplified RF signal drives the first PIN diode to conduct and reaches the RF system through the first PIN diode. The negative voltage signal of the amplified RF signal drives the second PIN diode to conduct and reaches the RF system through the second PIN diode.

[0014] When in the magnetic resonance receiving stage, since the RF power amplifier has no input signal, there is no output signal. Therefore, the first PIN diode and the second PIN diode are cut off, and the RF power amplifier and the RF system are in an open circuit state. As a result, external interference signals cannot enter the magnet compartment through the cable, thus preventing interference with the magnetic resonance signal.

[0015] In the above embodiments, by connecting two anti-parallel PIN diodes in series on the cable between the RF power amplifier and the RF system outside the magnet compartment, external interference signals are suppressed from entering the magnet compartment through the cable between the RF power amplifier and the RF system during the magnetic resonance receiving stage. This improves the anti-interference capability of the magnetic resonance system. Furthermore, the diodes are small in size, have high power handling capacity, fast switching speed, and low on-resistance. As a result, the entire device is small in size and does not affect the transmission of RF signals. The implementation method is very simple and does not require additional control signals.

[0016] A second aspect provides an anti-interference device for a magnetic resonance system, the device comprising: a first control signal generator, a first radio frequency choke, a first capacitor, a third PIN diode, a second capacitor, and a second radio frequency choke, wherein:

[0017] The output terminal of the first control signal generator is connected to the first connection terminal of the first radio frequency choke.

[0018] The second terminal of the first RF choke and the second terminal of the first capacitor are connected to the positive terminal of the third PIN diode;

[0019] The negative terminal of the third PIN diode is connected to the first connection terminal of the second capacitor and the first connection terminal of the second RF choke.

[0020] The second connection terminal of the second RF choke is grounded.

[0021] The first connection terminal of the first capacitor is the first external connection terminal of the anti-interference device of the magnetic resonance system, and the second connection terminal of the second capacitor is the second external connection terminal of the anti-interference device of the magnetic resonance system. The first external connection terminal is connected to the output terminal of the radio frequency power amplifier of the magnetic resonance system through a cable, and the second external connection terminal is connected to the radio frequency system inside the magnet compartment of the magnetic resonance system through a cable. The anti-interference device of the magnetic resonance system is located outside the magnet compartment.

[0022] When the magnetic resonance system is in the excitation phase, the first control signal generator outputs a positive DC signal. This positive DC signal passes through the first RF choke to the positive terminal of the third PIN diode, driving the third PIN diode to conduct. Thus, the amplified RF signal output by the RF power amplifier reaches the RF system via the first capacitor, the third PIN diode, and the second capacitor. The first RF choke and the second RF choke isolate the RF signal.

[0023] When the magnetic resonance system is in the receiving phase, the first control signal generator outputs a negative or zero-voltage DC signal, which cuts off the third PIN diode. The RF power amplifier and the RF system are in an open circuit state. Therefore, external RF interference signals cannot enter the magnet compartment through the cable, thus preventing interference with the magnetic resonance signal.

[0024] The above embodiments can also suppress external interference signals from entering the magnet space through the cable between the RF power amplifier and the RF system during the magnetic resonance receiving stage, thereby improving the anti-interference capability of the magnetic resonance system. Furthermore, the active method used results in less loss of RF signals and stronger suppression of interference signals.

[0025] In one optional embodiment, the capacitance values ​​of the first capacitor and the second capacitor satisfy the condition that the loss of the radio frequency signal output by the radio frequency power amplifier is minimized when it passes through the first capacitor and the second capacitor.

[0026] The third aspect also provides a magnetic resonance system anti-interference device, which, compared with the magnetic resonance system anti-interference device provided in the second aspect, further includes: a third radio frequency choke and a third capacitor, wherein:

[0027] The third RF choke and the third capacitor are connected in parallel and then in series between the second RF choke and the ground wire;

[0028] The resonant frequency of the third RF choke and the third capacitor is the magnetic resonance frequency.

[0029] The third RF choke and the third capacitor are connected in parallel to form a resonant circuit. This resonant circuit is open-circuited for RF interference signals from the ground wire.

[0030] The above embodiments further improve the device's anti-interference capability.

[0031] The fourth aspect also provides an anti-interference device for a magnetic resonance system, the device comprising: a second control signal generator, a fourth radio frequency choke, a fourth capacitor, a fourth PIN diode, and a fifth capacitor, wherein:

[0032] The output terminal of the second control signal generator is connected to the first connection terminal of the fourth radio frequency choke.

[0033] The second connection terminal of the fourth RF choke and the second connection terminal of the fourth capacitor, the first connection terminal of the fifth capacitor and the positive terminal of the fourth PIN diode are connected;

[0034] The negative terminal of the fourth PIN diode is grounded.

[0035] The first connection terminal of the fourth capacitor is the first external connection terminal of the anti-interference device of the magnetic resonance system, and the second connection terminal of the fifth capacitor is the second external connection terminal of the anti-interference device of the magnetic resonance system. The first external connection terminal is connected to the output terminal of the radio frequency power amplifier of the magnetic resonance system through a cable, and the second external connection terminal is connected to the radio frequency system inside the magnet compartment of the magnetic resonance system through a cable. The anti-interference device of the magnetic resonance system is located outside the magnet compartment.

[0036] When in the magnetic resonance excitation stage, the second control signal generator outputs a negative DC signal. This negative DC signal reaches the positive terminal of the fourth PIN diode through the fourth RF choke, thereby cutting off the fourth PIN diode. As a result, the amplified RF signal output by the RF power amplifier passes directly to the RF system through the fourth and fifth capacitors. The fourth RF choke isolates the RF signal.

[0037] When in the magnetic resonance receiving stage, the second control signal generator outputs a positive DC signal. This positive DC signal reaches the positive terminal of the fourth PIN diode through the fourth RF choke, thereby turning on the fourth PIN diode to form a short circuit to ground. As a result, all external RF interference signals are reflected and cannot enter the magnet space.

[0038] The above embodiments can also suppress external interference signals from entering the magnet space through the cable between the RF power amplifier and the RF system during the magnetic resonance receiving stage, thereby improving the anti-interference capability of the magnetic resonance system. Furthermore, the active method (with control signal) used results in less loss of RF signal and stronger suppression of interference signals.

[0039] In one optional embodiment, the capacitance values ​​of the fourth and fifth capacitors satisfy the condition that the loss of the RF signal output by the RF power amplifier is minimized when it passes through the fourth and fifth capacitors.

[0040] The fifth aspect also provides a magnetic resonance system anti-interference device, the device comprising: one or more of the above-described magnetic resonance system anti-interference devices connected in series. Preferably,

[0041] Multiple devices as described in the second or third aspect above, connected in series; or,

[0042] The device includes: a plurality of devices as described in the fourth aspect above, connected in series; or,

[0043] The device includes the following devices connected in series:

[0044] One or more devices as described in the first aspect above, and one or more devices as described in the second or third aspect above; or,

[0045] The device includes the following devices connected in series:

[0046] One or more devices as described in the first aspect above, and one or more devices as described in the fourth aspect above; or,

[0047] The device includes the following devices connected in series:

[0048] One or more devices as described in the second or third aspect above, and one or more devices as described in the fourth aspect above; or,

[0049] The device includes the following devices connected in series:

[0050] One or more devices as described in the first aspect above, one or more devices as described in the second or third aspect above, and one or more devices as described in the fourth aspect above;

[0051] In series connection, for any two adjacent devices, the second external connection terminal of one of the two devices is connected to the first external connection terminal of the other device.

[0052] Furthermore, after all devices are connected in series, the first external connection terminal of the device at the front is connected to the output terminal of the radio frequency power amplifier of the magnetic resonance system via a cable, and the second external connection terminal of the device at the back is connected to the radio frequency system inside the magnet compartment of the magnetic resonance system via a cable, and the anti-interference device of the magnetic resonance system is located outside the magnet compartment.

[0053] The above embodiments can further improve the suppression of external interference signals by the magnetic resonance system and achieve a higher isolation effect.

[0054] A sixth aspect provides a magnetic resonance system including an anti-interference device for a magnetic resonance system as described in any of the preceding aspects. Attached Figure Description

[0055] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which will make the above and other features and advantages of the present invention more apparent to those skilled in the art. In the drawings:

[0056] Figure 1 A schematic diagram of a typical existing magnetic resonance system;

[0057] Figure 2 This is a schematic diagram of the anti-interference device for a magnetic resonance system provided in the first embodiment of the present invention;

[0058] Figure 3 This is a schematic diagram of the anti-interference device for a magnetic resonance system provided in the second embodiment of the present invention;

[0059] Figure 4 This is a schematic diagram of the anti-interference device for a magnetic resonance system provided in the third embodiment of the present invention;

[0060] Figure 5 This is a schematic diagram of the anti-interference device for a magnetic resonance system provided in the fourth embodiment of the present invention;

[0061] Figure 6 This is a schematic diagram of the anti-interference device for a magnetic resonance system provided in the fifth embodiment of the present invention.

[0062] The reference numerals in the attached figures are as follows:

[0063]

[0064]

[0065] Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of the present invention clearer, the following embodiments are provided to further illustrate the present invention in detail.

[0067] Figure 2 This is a schematic diagram of the structure of the anti-interference device 21 for a magnetic resonance system provided in the first embodiment of the present invention. It mainly includes: a first PIN diode 211 and a second PIN diode 212, wherein:

[0068] The positive terminal of the first PIN diode 211 and the negative terminal of the second PIN diode 212 are connected to form the first external connection terminal 213 of the magnetic resonance system anti-interference device 21;

[0069] The negative terminal of the first PIN diode 211 and the positive terminal of the second PIN diode 212 are connected to form the second external connection terminal 214 of the magnetic resonance system anti-interference device 21;

[0070] The first external connection terminal 213 is connected to the output terminal of the radio frequency power amplifier 500 of the magnetic resonance system via a cable, and the second external connection terminal 214 is connected to the radio frequency system 201 inside the magnet compartment 200 of the magnetic resonance system via a cable, and the anti-interference device 21 of the magnetic resonance system is located outside the magnet compartment 200.

[0071] When in the magnetic resonance excitation stage, the RF power amplifier 500 amplifies the input RF signal and outputs the amplified RF signal. The amplified RF signal reaches the magnetic resonance system anti-interference device 21 through the cable. The positive voltage signal of the amplified RF signal drives the first PIN diode 211 to conduct and reaches the RF system 201 through the first PIN diode 211. The negative voltage signal of the amplified RF signal drives the second PIN diode 212 to conduct and reaches the RF system 201 through the second PIN diode 212.

[0072] When in the magnetic resonance receiving stage, since the RF power amplifier 500 has no input signal, it has no output signal. Therefore, the first PIN diode 211 and the second PIN diode 212 are cut off, and the RF power amplifier 500 and the RF system 201 are in an open circuit state. Therefore, external interference signals cannot enter the magnet chamber 200 through the cable, thus not interfering with the magnetic resonance signal.

[0073] In the above embodiments, by connecting two anti-parallel PIN diodes in series on the cable between the RF power amplifier and the RF system outside the magnet compartment, external interference signals are suppressed from entering the magnet compartment through the cable between the RF power amplifier and the RF system during the magnetic resonance receiving stage. This improves the anti-interference capability of the magnetic resonance system. Furthermore, the diodes are small in size, have high power handling capacity, fast switching speed, and low on-resistance. As a result, the entire device is small in size and does not affect the transmission of RF signals. The implementation method is very simple and does not require additional control signals.

[0074] Figure 3 This is a schematic diagram of the structure of the anti-interference device 31 for a magnetic resonance system provided in the second embodiment of the present invention. The device 31 mainly includes: a first control signal generator 311, a first radio frequency choke 312, a first capacitor 313, a third PIN diode 314, a second capacitor 315, and a second radio frequency choke 316, wherein:

[0075] The output terminal of the first control signal generator 311 is connected to the first connection terminal of the first radio frequency choke 312;

[0076] The second connection terminal of the first RF choke 312 and the second connection terminal of the first capacitor 313 are connected to the positive terminal of the third PIN diode 314;

[0077] The negative terminal of the third PIN diode 314 is connected to the first connection terminal of the second capacitor 315 and the first connection terminal of the second RF choke 316.

[0078] The second connection terminal of the second RF choke 316 is grounded.

[0079] The first connection terminal 3131 of the first capacitor 313 is the first external connection terminal of the magnetic resonance system anti-interference device 31, and the second connection terminal 3152 of the second capacitor 315 is the second external connection terminal of the magnetic resonance system anti-interference device 31.

[0080] The first external connection terminal 3131 is connected to the output terminal of the radio frequency power amplifier 500 of the magnetic resonance system via a cable. The second external connection terminal 3152 is connected to the radio frequency system 201 inside the magnet compartment 200 of the magnetic resonance system via a cable. The anti-interference device 31 of the magnetic resonance system is located outside the magnet compartment 200.

[0081] When in the magnetic resonance excitation stage, the first control signal generator 311 outputs a positive DC signal. This positive DC signal passes through the first RF choke 312 to the positive terminal of the third PIN diode 314, driving the third PIN diode 314 to conduct. Thus, the amplified RF signal output by the RF power amplifier 500 reaches the RF system 201 via the first capacitor 313, the third PIN diode 314, and the second capacitor 315. The first RF choke 312 and the second RF choke 316 isolate the RF signal.

[0082] When in the magnetic resonance receiving stage, the first control signal generator 311 outputs a negative or zero-voltage DC signal, thereby cutting off the third PIN diode 314. The RF power amplifier 500 and the RF system 201 are in an open circuit state. Therefore, external RF interference signals cannot enter the magnet chamber 200 through the cable, thus not interfering with the magnetic resonance signal.

[0083] As can be seen, the above embodiments can also suppress external interference signals from entering the magnet chamber through the cable between the RF power amplifier and the RF system during the magnetic resonance receiving stage, thereby improving the anti-interference capability of the magnetic resonance system. Figure 2 Compared to the device shown, the active method (with control signal) used in this embodiment results in less loss of radio frequency signal and stronger suppression of interference signal.

[0084] The capacitance values ​​of the first capacitor 313 and the second capacitor 315 satisfy the condition that the loss of the RF signal output by the RF power amplifier 500 is minimized when it passes through the first capacitor 313 and the second capacitor 315.

[0085] Considering: when Figure 3 When the RF choke 316 in the circuit does not provide sufficient isolation for RF signals, interference signals may enter the signal line from the ground line through the RF choke 316, thereby entering the magnet compartment 200. To suppress interference signals from the ground line, embodiments of the present invention provide, as follows: Figure 4 The solution shown:

[0086] Figure 4 A schematic diagram of the structure of the anti-interference device 31 for a magnetic resonance system provided in the third embodiment of the present invention is given. The device 31 further includes: a third radio frequency choke 317 and a third capacitor 318, wherein:

[0087] The third RF choke 317 and the third capacitor 318 are connected in parallel and then in series between the second RF choke 316 and the ground wire.

[0088] Furthermore, the resonant frequencies of the third RF choke 317 and the third capacitor 318 are magnetic resonance frequencies.

[0089] As can be seen, the third RF choke 317 and the third capacitor 318 are connected in parallel to form a resonant circuit. For RF interference signals from the ground wire, the resonant circuit is in an open circuit state, thereby further improving the anti-interference capability of the device 31.

[0090] Figure 5 This is a schematic diagram of the structure of the anti-interference device 51 for a magnetic resonance system provided in the fourth embodiment of the present invention. The device 51 mainly includes: a second control signal generator 511, a fourth radio frequency choke 512, a fourth capacitor 513, a fourth PIN diode 514, and a fifth capacitor 515, wherein:

[0091] The output terminal of the second control signal generator 511 is connected to the first connection terminal of the fourth radio frequency choke 512;

[0092] The second connection terminal of the fourth RF choke 512 and the second connection terminal of the fourth capacitor 513, the first connection terminal of the fifth capacitor 515 and the positive terminal of the fourth PIN diode 514 are connected.

[0093] The negative terminal of the fourth PIN diode 514 is grounded;

[0094] The first connection terminal 5131 of the fourth capacitor 513 serves as the first external connection terminal of the magnetic resonance system anti-interference device 51, and the second connection terminal 5152 of the fifth capacitor 515 serves as the second external connection terminal of the magnetic resonance system anti-interference device 51.

[0095] The first external connection terminal 5131 of the magnetic resonance system anti-interference device 51 is connected to the output terminal of the radio frequency power amplifier 500 of the magnetic resonance system via a cable. The second external connection terminal 5152 of the magnetic resonance system anti-interference device 51 is connected to the radio frequency system 201 inside the magnet compartment 200 of the magnetic resonance system via a cable. The magnetic resonance system anti-interference device 21 is located outside the magnet compartment 200.

[0096] When in the magnetic resonance excitation stage, the second control signal generator 511 outputs a negative DC signal. This negative DC signal reaches the positive terminal of the fourth PIN diode 514 through the fourth RF choke 512, thereby cutting off the fourth PIN diode 514. As a result, the amplified RF signal output by the RF power amplifier 500 is directly connected to the RF system 201 via the fourth capacitor 513 and the fifth capacitor 515. The fourth RF choke 512 isolates the RF signal.

[0097] When in the magnetic resonance receiving stage, the second control signal generator 511 outputs a positive DC signal. This positive DC signal reaches the positive terminal of the fourth PIN diode 514 through the fourth RF choke 512, thereby turning on the fourth PIN diode 514 to form a short circuit to the ground, so that all external RF interference signals are reflected and cannot enter the magnet space 200.

[0098] As can be seen, the above embodiments can also suppress external interference signals from entering the magnet chamber through the cable between the RF power amplifier and the RF system during the magnetic resonance receiving stage, thereby improving the anti-interference capability of the magnetic resonance system. Figure 2 Compared to the device shown, the active method (with control signal) used in this embodiment results in less loss of radio frequency signal and stronger suppression of interference signal.

[0099] Among them, the capacitance values ​​of the fourth capacitor 513 and the fifth capacitor 515 satisfy the condition that the loss of the RF signal output by the RF power amplifier 500 is minimized when it passes through the fourth capacitor 513 and the fifth capacitor 515.

[0100] This invention also provides an anti-interference device for a magnetic resonance system, comprising: a plurality of devices 31 connected in series as described in the second or third embodiment above; or,

[0101] Includes: a plurality of devices 51 as described in the fourth embodiment above, connected in series; or,

[0102] Includes: devices connected in series: one or more devices 21 as described in the first embodiment above, and one or more devices 31 as described in the second or third embodiment above; or,

[0103] Includes: devices connected in series: one or more devices 21 as described in the first embodiment above, and one or more devices 51 as described in the fourth embodiment above; or,

[0104] Includes: devices connected in series: one or more devices 31 as described in the second or third embodiment above, and one or more devices 51 as described in the fourth embodiment above; or,

[0105] Includes: the following devices connected in series:

[0106] One or more devices 21 as described in the first embodiment above, one or more devices 31 as described in the second or third embodiment above, and one or more devices 51 as described in the fourth embodiment above;

[0107] In series connection, for any two adjacent devices (one of which is such as 21, 31 or 51 in the above embodiments), the second external connection terminal of one of the two devices is connected to the first external connection terminal of the other device.

[0108] Furthermore, after all the devices are connected in series, the first external connection terminal of the device at the front (21 or 31 or 51) is connected to the output terminal of the radio frequency power amplifier 500 of the magnetic resonance system via a cable, and the second external connection terminal of the device at the back (21 or 31 or 51) is connected to the radio frequency system 201 inside the magnet compartment 200 of the magnetic resonance system via a cable, and all devices (21 or 31 or 51) are located outside the magnet compartment 200.

[0109] The above embodiments can further improve the suppression of external interference signals by the magnetic resonance system and achieve a higher isolation effect.

[0110] Figure 6 The present invention provides a schematic diagram of the structure of a magnetic resonance system anti-interference device 61 according to the fifth embodiment of the present invention. The device 61 includes three devices connected in series: a device 21 as described in the first embodiment above, a device 31 as described in the third embodiment above, and a device 51 as described in the fourth embodiment above.

[0111] The magnetic resonance system proposed in the embodiments of the present invention may include the anti-interference device for the magnetic resonance system provided in any of the above embodiments.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An anti-interference device (31) for a magnetic resonance system, characterized in that, The device (31) includes: a first control signal generator (311), a first radio frequency choke (312), a first capacitor (313), a third PIN diode (314), a second capacitor (315), and a second radio frequency choke (316), wherein: The output terminal of the first control signal generator (311) is connected to the first connection terminal of the first radio frequency choke (312); The second connection terminal of the first RF choke (312) and the second connection terminal of the first capacitor (313) are connected to the positive terminal of the third PIN diode (314); The negative terminal of the third PIN diode (314) and the first connection terminal of the second capacitor (315) are connected to the first connection terminal of the second radio frequency choke (316); The second connection terminal of the second RF choke (316) is grounded; The first connection terminal (3131) of the first capacitor (313) is the first external connection terminal of the magnetic resonance system anti-interference device (31), and the second connection terminal (3152) of the second capacitor (315) is the second external connection terminal of the magnetic resonance system anti-interference device (31); the first external connection terminal of the magnetic resonance system anti-interference device (31) is connected to the output terminal of the radio frequency power amplifier (500) of the magnetic resonance system through a cable, and the second external connection terminal of the magnetic resonance system anti-interference device (31) is connected to the radio frequency system (201) inside the magnet compartment (200) of the magnetic resonance system through a cable, and the magnetic resonance system anti-interference device (31) is located outside the magnet compartment (200); When the magnetic resonance system is in the excitation phase, the first control signal generator (311) outputs a positive DC signal. This positive DC signal reaches the positive terminal of the third PIN diode (314) through the first RF choke (312), driving the third PIN diode (314) to conduct. Thus, the amplified RF signal output by the RF power amplifier (500) reaches the RF system (201) via the first capacitor (313), the third PIN diode (314), and the second capacitor (315). The first RF choke (312) and the second RF choke (316) isolate the RF signal. When the magnetic resonance system is in the receiving phase, the first control signal generator (311) outputs a negative or zero-voltage DC signal, thereby turning off the third PIN diode (314). The radio frequency power amplifier (500) and the radio frequency system (201) are in an open circuit state. Therefore, external radio frequency interference signals cannot enter the magnet compartment (200) through the cable, thus not interfering with the magnetic resonance signal.

2. The device (31) according to claim 1, characterized in that, The capacitance values ​​of the first capacitor (313) and the second capacitor (315) satisfy the condition that the loss of the radio frequency signal output by the radio frequency power amplifier (500) is minimized when it passes through the first capacitor (313) and the second capacitor (315).

3. The device (31) according to claim 1, characterized in that, The device (31) further includes: a third radio frequency choke (317) and a third capacitor (318), wherein: The third RF choke (317) and the third capacitor (318) are connected in parallel and then in series between the second RF choke (316) and the ground wire; The resonant frequencies of the third radio frequency choke (317) and the third capacitor (318) are magnetic resonance frequencies. The third radio frequency choke (317) and the third capacitor (318) are connected in parallel to form a resonant circuit. The resonant circuit is in an open circuit state for radio frequency interference signals from the ground wire.

4. An anti-interference device (51) for a magnetic resonance system, characterized in that, The device (51) includes: a second control signal generator (511), a fourth radio frequency choke (512), a fourth capacitor (513), a fourth PIN diode (514), and a fifth capacitor (515), wherein: The output terminal of the second control signal generator (511) is connected to the first connection terminal of the fourth radio frequency choke (512); The second connection terminal of the fourth RF choke (512) and the second connection terminal of the fourth capacitor (513), the first connection terminal of the fifth capacitor (515) and the positive terminal of the fourth PIN diode (514) are connected. The negative terminal of the fourth PIN diode (514) is grounded; The first connection terminal (5131) of the fourth capacitor (513) is the first external connection terminal of the magnetic resonance system anti-interference device (51), and the second connection terminal (5152) of the fifth capacitor (515) is the second external connection terminal of the magnetic resonance system anti-interference device (51). The first external connection terminal of the magnetic resonance system anti-interference device (51) is connected to the output terminal of the radio frequency power amplifier (500) of the magnetic resonance system through a cable, and the second external connection terminal of the magnetic resonance system anti-interference device (51) is connected to the radio frequency system (201) inside the magnet compartment (200) of the magnetic resonance system through a cable. The magnetic resonance system anti-interference device (51) is located outside the magnet compartment (200). When in the magnetic resonance excitation stage, the second control signal generator (511) outputs a negative DC signal, which passes through the fourth RF choke (512) to the positive terminal of the fourth PIN diode (514), thereby cutting off the fourth PIN diode (514). As a result, the amplified RF signal output by the RF power amplifier (500) passes through the fourth capacitor (513) and the fifth capacitor (515) to the RF system (201); wherein, the fourth RF choke (512) isolates the RF signal; When in the magnetic resonance receiving stage, the second control signal generator (511) outputs a positive DC signal. This positive DC signal reaches the positive terminal of the fourth PIN diode (514) through the fourth RF choke (512), thereby turning on the fourth PIN diode (514) to form a short circuit to the ground, so that all external RF interference signals are reflected and cannot enter the magnet space (200).

5. The apparatus (51) according to claim 4, characterized in that, The capacitance values ​​of the fourth capacitor (513) and the fifth capacitor (515) satisfy the condition that the loss of the radio frequency signal output by the radio frequency power amplifier (500) is minimized when it passes through the fourth capacitor (513) and the fifth capacitor (515).

6. An anti-interference device (61) for a magnetic resonance system, characterized in that, The device includes: One or more of the magnetic resonance system anti-interference devices as described in any one of claims 1 to 5 are connected in series. Furthermore, after all devices (31, 51) are connected in series, the first external connection end of the device (31, 51) located at the front is connected to the output end of the radio frequency power amplifier (500) of the magnetic resonance system via a cable, and the second external connection end of the device (31, 51) located at the back is connected to the radio frequency system (201) inside the magnet compartment (200) of the magnetic resonance system via a cable, and the anti-interference device (61) of the magnetic resonance system is located outside the magnet compartment (200).

7. A magnetic resonance system, characterized in that, Includes the anti-interference device for magnetic resonance systems (31, 51, 61) as described in any one of claims 1 to 6.

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