Local Coil and Magnetic Resonance Imaging System

Abstract

The present application relates to a local coil and magnetic resonance imaging system, wherein the local coil includes: a receiving unit, a first resonant circuit, and a second resonant circuit; the first resonant circuit and the second resonant circuit are arranged opposite each other; the receiving unit is connected to the first resonant circuit and the second resonant circuit, respectively, and is configured to receive magnetic resonance pulse signals transmitted by an external volume coil; when receiving the magnetic resonance pulse signals, the diode D1 in the first resonant circuit is turned on, or the diode D2 in the second resonant circuit is turned on, depending on the positive or negative sign of the magnetic resonance pulse signals, to detune the local coil. This application solves the problem in related arts of requiring an active current signal to control the detune of the local coil, which complicates the circuit structure and wastes resources. This eliminates the need for an additional active current signal for control, thereby simplifying the circuit and reducing resource waste.

Description

Technical Field

[0001] The present application relates to the technical field of magnetic resonance imaging, and in particular to a local coil and a magnetic resonance imaging system. Background Art

[0002] Magnetic resonance imaging (MRI) systems, a medical diagnostic system developed since the 1980s, can noninvasively acquire images of any section of the human body, providing anatomical information. To achieve high-quality images, MRI systems use a volumetric coil for transmission and a local coil for reception of magnetic resonance pulse signals. This allows for images with good uniformity and a high signal-to-noise ratio.

[0003] Currently, MRI systems provide active current signals to control the detuning of the volume coil during transmission, to prevent the local coil from interfering with the transmission. However, as the number of local coil channels increases, the power consumption of the active current signal within the MRI system increases, complicating the circuit structure and wasting resources.

[0004] There is a problem in the related art that an active current signal needs to be provided to control the detuning of the local coil, which makes the circuit structure complicated and causes waste of resources. Currently, no effective solution has been proposed. Summary of the Invention

[0005] This embodiment provides a local coil and a magnetic resonance imaging system to solve the problem in the related art that an active current signal needs to be provided to control the detuning of the local coil, which makes the circuit structure complex and causes waste of resources.

[0006] In a first aspect, a local coil is provided in this embodiment, comprising: a receiving unit (100), a first resonant circuit (200), and a second resonant circuit (300);

[0007] The first resonant circuit (200) and the second resonant circuit (300) are arranged opposite to each other;

[0008] The receiving unit (100) is connected to the first resonant circuit (200) and the second resonant circuit (300) respectively, and is used to receive the magnetic resonance pulse signal emitted by the external volume coil;

[0009] When receiving the magnetic resonance pulse signal, the diode D1 in the first resonant circuit (200) is turned on, or the diode D2 in the second resonant circuit (300) is turned on, depending on the positive or negative sign of the magnetic resonance pulse signal, so that the local coil is in a detuned state.

[0010] In some embodiments, the first resonant circuit (200) includes: a resonant inductor L1, a resonant capacitor C5, and a diode D1;

[0011] One end of the resonant inductor L1 is connected to one end of the resonant capacitor C5 and the receiving unit (100), respectively; the other end of the resonant inductor L1 is connected to one end of the diode D1 and the second resonant circuit (300), respectively;

[0012] The other end of the resonant capacitor C5 is connected to the other end of the diode D1 and the second resonant circuit (300) respectively and then grounded.

[0013] In some embodiments, the second resonant circuit (300) includes: a resonant inductor L2, a resonant capacitor C4, and a diode D2;

[0014] One end of the resonant inductor L2 is connected to one end of the resonant capacitor C4 and the receiving unit (100), respectively; the other end of the resonant inductor L2 is connected to one end of the diode D2 and the first resonant circuit (200), respectively, and then grounded;

[0015] The other end of the resonant capacitor C4 is connected to the other end of the diode D2 and the first resonant circuit (200) respectively.

[0016] In some embodiments, the conduction direction of the diode D1 of the first resonant circuit (200) is opposite to the conduction direction of the diode D2 of the second resonant circuit (300).

[0017] In some embodiments thereof, the receiving unit (100) includes: a capacitor C1, a capacitor C2, and a capacitor C3;

[0018] One end of the capacitor C3 is connected to one end of the capacitor C1, and the other end of the capacitor C3 is connected to one end of the capacitor C2;

[0019] The other end of the capacitor C1 is connected to the first resonant circuit (200);

[0020] The other end of the capacitor C2 is connected to the second resonant circuit (300).

[0021] In some of the embodiments, the local coil provided in this embodiment further includes a low noise amplifier (400);

[0022] The low noise amplifier (400) is connected to the receiving unit (100) via the first resonant circuit (200) and the second resonant circuit (300), and is used to adjust the signal-to-noise ratio of the local coil.

[0023] In some embodiments thereof, the resonant inductor L1 and the resonant capacitor C5 in the first resonant circuit (200) and the resonant inductor L2 and the resonant capacitor C4 in the second resonant circuit (300) form an impedance conversion circuit for converting the input impedance of the low-noise amplifier (400).

[0024] In some embodiments, the input impedance of the low noise amplifier (400) is less than 2 ohms.

[0025] In a second aspect, this embodiment provides a magnetic resonance imaging system, comprising the local coil as described in the first aspect.

[0026] In some of the embodiments, the magnetic resonance imaging system provided in this embodiment further includes a volume coil;

[0027] The volume coil is coupled to the local coil and is used to transmit magnetic resonance pulse signals.

[0028] Compared with related art, the local coil and magnetic resonance imaging system provided in this embodiment include a receiving unit, a first resonant circuit, and a second resonant circuit. The first resonant circuit and the second resonant circuit are arranged opposite each other. The receiving unit is connected to the first resonant circuit and the second resonant circuit, respectively, and is configured to receive magnetic resonance pulse signals transmitted by an external volume coil. When receiving the magnetic resonance pulse signals, the diode D1 in the first resonant circuit is turned on, or the diode D2 in the second resonant circuit is turned on, depending on the positive or negative sign of the magnetic resonance pulse signals, to detune the local coil. This achieves detune control of the local coil based on the positive or negative sign of the received magnetic resonance pulse signals without requiring additional active current signals for control, thereby simplifying the circuit, reducing production costs, and minimizing resource waste. This solves the problem in related art of requiring an active current signal to control the detune of the local coil, which complicates the circuit structure and wastes resources.

[0029] The details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0031] Figure 1 This is a structural block diagram of a local coil provided in one embodiment of the present application;

[0032] Figure 2 is a structural block diagram of a local coil provided by another embodiment of the present application;

[0033] Figure 3 It is a structural block diagram of the local coil of the preferred embodiment of the present application.

[0034] In the figure: 100, receiving unit; 200, first resonant circuit; 300, second resonant circuit; 400, low noise amplifier. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the contents disclosed in the present application, some changes such as design, manufacturing or production based on the technical contents disclosed in the present application are only conventional technical means and should not be understood as the contents disclosed in the present application being insufficient.

[0036] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments unless there is a conflict.

[0037] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meanings understood by persons of ordinary skill in the art to which this application belongs. In this application, when an element is referred to as being "provided on" another element, it may be provided directly on the other element or there may also be a central element. When an element is considered to be "provided on" another element, it may be provided directly on the other element or there may also be a central element. When an element is considered to be "fixed to" another element, it may be fixed directly on the other element or there may also be a central element. In this application, words such as "one", "a", "the", "these" and the like do not indicate a limit on quantity and may be singular or plural. The terms "include", "comprising", "having" and any variations thereof used in this application are intended to cover non-exclusive inclusions; for example, a process, method and system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include steps or modules (units) that are not listed, or may include other steps or modules (units) inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like mentioned in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "plurality" mentioned in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" may mean: A exists alone, A and B exist at the same time, and B exists alone. Generally, the character " / " indicates that the objects associated before and after are in an "or" relationship. The terms "first", "second", "third" and the like mentioned in this application are only used to distinguish similar objects and do not represent a specific ordering of objects. The terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0038] In this embodiment, a local coil is provided. Figure 1 is a structural block diagram of the local coil of this embodiment, as shown in FIG. Figure 1 As shown, the local coil includes: a receiving unit 100, a first resonant circuit 200 and a second resonant circuit 300;

[0039] The first resonant circuit 200 and the second resonant circuit 300 are arranged opposite to each other;

[0040] The receiving unit 100 is connected to the first resonant circuit 200 and the second resonant circuit 300 respectively, and is used to receive the magnetic resonance pulse signal transmitted by the external volume coil;

[0041] When receiving the magnetic resonance pulse signal, the diode D1 in the first resonant circuit 200 is turned on, or the diode D2 in the second resonant circuit 300 is turned on, depending on the positive or negative sign of the magnetic resonance pulse signal, so that the local coil is in a detuned state.

[0042] It should be noted that the receiving unit 100 is the antenna in the local coil. It is connected in series with the coils in the first resonant circuit 200 and the second resonant circuit 300 to receive magnetic resonance pulse signals transmitted by the external volume coil. The first resonant circuit 200 and the second resonant circuit 300 are arranged opposite each other. When the first resonant circuit 200 is in a detuned state, the second resonant circuit 300 is inoperative. Conversely, when the second resonant circuit 300 is in a detuned state, the first resonant circuit 200 is inoperative. At any given time, only one of the two resonant circuits is in a detuned state.

[0043] Specifically, the positive or negative polarity of the magnetic resonance pulse signal (positive or negative) is utilized to cause the diode D1 in the first resonant circuit 200 or the diode D2 in the second resonant circuit 300 to be conductive. If the diode D1 in the first resonant circuit 200 is conductive, the first resonant circuit 200 is detuned, causing all receiving coils to be detuned as well. If the diode D2 in the second resonant circuit 300 is conductive, the detuned state of the second resonant circuit 300 also causes all receiving coils to be detuned.

[0044] The local coil receives magnetic resonance pulse signals emitted by the external volume coil. Both the local coil and the volume coil have inductive properties, resulting in inductive coupling between them. Fluctuations in magnetic flux can affect the flux of nearby local coils and volume coils. This means that when the local coil and volume coil are in close proximity, they influence each other. To prevent this influence, the local coil must be detuned when the external volume coil is in operation. Detuning here refers to detuning the local coil frequency away from the resonant frequency. When the local coil frequency is far from the resonant point, it will not couple with and influence other coils. In scenarios where multiple local coils are used, local coils can also influence each other, so unused local coils should also be detuned.

[0045] In the prior art, the magnetic resonance imaging system provides an active current signal to control the detuning of the local coil. However, the present application uses a first resonant circuit 200 and a second resonant circuit 300 arranged opposite to each other, and automatically achieves detuning of the local coil based on the positive or negative sign of the magnetic resonance pulse signal. This eliminates the need for additional active current signal control, thereby simplifying the circuit, reducing production costs, and minimizing resource waste.

[0046] In some embodiments, the first resonant circuit 200 includes: a resonant inductor L1, a resonant capacitor C5, and a diode D1;

[0047] One end of the resonant inductor L1 is connected to one end of the resonant capacitor C5 and the receiving unit 100 respectively; the other end of the resonant inductor L1 is connected to one end of the diode D1 and the second resonant circuit 300 respectively;

[0048] The other end of the resonant capacitor C5 is connected to the other end of the diode D1 and the second resonant circuit 300 respectively and then grounded.

[0049] Specifically, the resonant inductor L1 is connected in series with the other end of the capacitor C1 of the receiving unit 100, and the resonant capacitor C5 is connected in parallel with the resonant inductor L1 and the diode D1. When the diode D1 is in the on state, the first resonant circuit 200 is in a detuned state. In other embodiments, the first resonant circuit 200 can have various forms, for example, a multi-inductor structure. The resistor R1 can be provided after the resonant inductor L1, etc., without limitation.

[0050] In some embodiments, the second resonant circuit 300 includes: a resonant inductor L2, a resonant capacitor C4, and a diode D2;

[0051] One end of the resonant inductor L2 is connected to one end of the resonant capacitor C4 and the receiving unit 100 respectively; the other end of the resonant inductor L2 is connected to one end of the diode D2 and the first resonant circuit 200 respectively and then grounded;

[0052] The other end of the resonant capacitor C4 is connected to the other end of the diode D2 and the first resonant circuit 200 , respectively.

[0053] Specifically, the resonant inductor L2 is connected in series with the other end of the capacitor C2 of the receiving unit 100, and the resonant capacitor C4 is connected in parallel with the resonant inductor L2 and the diode D2. When the diode D2 is in the on state, the second resonant circuit 300 is in a detuned state. In other embodiments, the second resonant circuit 300 can have various forms, for example, a multi-inductor structure. The resistor R2 can be provided after the resonant inductor L2, etc., without limitation.

[0054] In some embodiments, the conducting direction of the diode D1 of the first resonant circuit 200 is opposite to the conducting direction of the diode D2 of the second resonant circuit 300 .

[0055] Diodes D1 and D2 are configured to conduct electricity in opposite directions to respond to positive and negative pulses in the magnetic resonance pulse signal, respectively. For example, in response to a positive pulse in the magnetic resonance pulse signal, diode D1 of the first resonant circuit 200 is turned on, while diode D2 of the second resonant circuit 300 is turned off. In response to a negative pulse in the magnetic resonance pulse signal, diode D1 of the first resonant circuit 200 is turned off, while diode D2 of the second resonant circuit 300 is turned on, thereby automatically detuning the local coil.

[0056] In some embodiments, the receiving unit 100 includes: a capacitor C1, a capacitor C2, and a capacitor C3;

[0057] One end of the capacitor C3 is connected to one end of the capacitor C1, and the other end of the capacitor C3 is connected to one end of the capacitor C2;

[0058] The other end of the capacitor C1 is connected to the first resonant circuit 200;

[0059] The other end of the capacitor C2 is connected to the second resonant circuit 300 .

[0060] Specifically, the other end of capacitor C1 is connected to one end of resonant inductor L1 and one end of resonant capacitor C5 in the first resonant circuit 200. The other end of capacitor C2 is connected to one end of resonant inductor L2 and one end of resonant capacitor C4 in the second resonant circuit 300. Capacitor C1, capacitor C2, capacitor C3, resonant inductor L1, and resonant inductor L2 are connected in series to form a resonant coil loop.

[0061] In some of these embodiments, Figure 2 As shown, in order to obtain an image with good uniformity and high signal-to-noise ratio. Figure 1 Based on the embodiment, it further includes a low noise amplifier 400;

[0062] The low noise amplifier 400 is connected to the receiving unit 100 via the first resonant circuit 200 and the second resonant circuit 300 , and is used to adjust the signal-to-noise ratio of the local coil.

[0063] Specifically, the input end of low-noise amplifier 400 is connected to one end of diode D1 in first resonant circuit 200, the other end of resonant inductor L1, the other end of diode D2 in second resonant circuit 300, and the other end of resonant inductor L1, respectively. The other end of diode D1 and one end of diode D2 are connected and then grounded. A low-noise amplifier has a very low noise figure and can be considered a preamplifier. When amplifying weak signals, the amplifier's own noise can significantly interfere with the signal. Therefore, a low-noise amplifier is used to improve the output signal-to-noise ratio.

[0064] It should be noted that when the low-noise amplifier 400 is operating, the diode D1 and the diode D2 are both in a non-conducting state, and the resonant inductor L1 and the resonant capacitor C5 in the first resonant circuit (200) and the resonant inductor L2 and the resonant capacitor C4 in the second resonant circuit (300) form an impedance conversion circuit, which is connected to the low-noise amplifier 400. The impedance conversion circuit is used to convert the input impedance of the low-noise amplifier (400).

[0065] The present embodiment is described and illustrated below through preferred embodiments.

[0066] Figure 3 FIG. 4 is a structural block diagram of the local coil of the preferred embodiment.

[0067] In this embodiment, the local coil includes: a receiving unit 100, a first resonant circuit 200, a second resonant circuit 300, and a low noise amplifier 400;

[0068] The first resonant circuit 200 and the second resonant circuit 300 are arranged opposite to each other;

[0069] The receiving unit 100 includes: capacitors C1, C2, and C3; and is used to receive magnetic resonance pulse signals transmitted by an external volume coil.

[0070] One end of the capacitor C3 is connected to one end of the capacitor C1, and the other end of the capacitor C3 is connected to one end of the capacitor C2;

[0071] The first resonant circuit 200 includes: a resonant inductor L1, a resonant capacitor C5 and a diode D1;

[0072] One end of the resonant inductor L1 is connected to one end of the resonant capacitor C5 and the other end of the capacitor C1 respectively; the other end of the resonant inductor L1 is connected to one end of the diode D1, the other end of the diode D2, the other end of the resonant capacitor C4, and the input end of the low noise amplifier 400 respectively;

[0073] The other end of the resonant capacitor C5 is respectively connected to the other end of the diode D1 , one end of the diode D2 , and the other end of the resonant inductor L2 and then grounded.

[0074] The second resonant circuit 300 includes: a resonant inductor L2, a resonant capacitor C4 and a diode D2;

[0075] One end of the resonant inductor L2 is connected to one end of the resonant capacitor C4 and the other end of the capacitor C2 respectively.

[0076] The conducting direction of the diode D1 of the first resonant circuit 200 is opposite to the conducting direction of the diode D2 of the second resonant circuit 300 .

[0077] The low noise amplifier 400 is connected to the receiving unit 100 via the first resonant circuit 200 and the second resonant circuit 300 , and is used to adjust the signal-to-noise ratio of the local coil.

[0078] When receiving the magnetic resonance pulse signal, the diode D1 in the first resonant circuit 200 is turned on, or the diode D2 in the second resonant circuit 300 is turned on, depending on the positive or negative sign of the magnetic resonance pulse signal, so that the local coil is in a detuned state.

[0079] The input impedance of the low-noise amplifier 400 is less than 2 ohms. The input impedance of the low-noise amplifier 400 can be 1.9 ohms, 1.5 ohms, 1 ohm, 0.9 ohms, 0.8 ohms, 0.7 ohms, 0.5 ohms, 0.2 ohms, etc., not listed here. In this embodiment, the input impedance of the low-noise amplifier 400 is 1 ohm. Capacitor C1, capacitor C2, capacitor C3, resonant inductor L1, and resonant inductor L2 are connected in series to form a resonant coil loop.

[0080] If the load impedance of the coil loop is R3 and the source impedance of the low noise amplifier 400 is Rs, then the resonant inductor L1 and the resonant inductor L2 need to satisfy:

[0081] Resonant inductance L1 = resonant inductance L2 = Zc / w;

[0082] Wherein, Zc=sqrt(R3*Rs); w=2*pi*f; f is the operating frequency of the magnetic resonance imaging system; and Rs is greater than 150 ohms.

[0083] The resonant capacitor C4 and the resonant capacitor C5 need to meet the following requirements:

[0084] Resonant capacitance C4 = resonant capacitance C5 = 1 / (w*Zc).

[0085] The resonant inductor L1, resonant capacitor C5, resonant inductor L2, and resonant capacitor C4 form an impedance conversion circuit for transforming the input impedance of the low-noise amplifier 400. This converts the low input impedance of the low-noise amplifier 400 into a high impedance at the AB terminals. This allows the coil loop to achieve an effect similar to active detuning, even without active detuning. During external volume coil transmission, either diode D1 or diode D2 conducts. The resonant inductor L1 and resonant capacitor C5, and the resonant inductor L2 and resonant capacitor C4, form two series-connected detuned loops, placing the local coil in a detuned state. During local coil reception, the high impedance at the AB terminals in the coil loop also creates a detuned state similar to that of the local coil. These two features eliminate the need for the MRI system to provide additional current for controlling detuning, reducing local coil power consumption. On the other hand, due to the high impedance of the AB end of the coil loop during tuning, the coil loop has very little coupling with the adjacent coil, thereby achieving the effect of decoupling other coils that may be coupled. The coil loop can then be overlapped, thereby increasing the coil density per unit area.

[0086] In addition, in combination with the local coils in the above embodiments, the present invention can provide a magnetic resonance imaging system to implement the present invention. The magnetic resonance imaging system includes any one of the local coils in the above embodiments.

[0087] For example, the local coil includes a receiving unit 100, a first resonant circuit 200, and a second resonant circuit 300. The first resonant circuit 200 and the second resonant circuit 300 are arranged opposite each other. The receiving unit 100 is connected to the first resonant circuit 200 and the second resonant circuit 300, respectively, and is configured to receive magnetic resonance pulse signals transmitted by an external volume coil. When receiving the magnetic resonance pulse signals, the diode D1 in the first resonant circuit 200 or the diode D2 in the second resonant circuit 300 is turned on, depending on the positive or negative sign of the magnetic resonance pulse signals, so that the local coil is detuned.

[0088] For example, a local coil includes a receiving unit 100, a first resonant circuit 200, a second resonant circuit 300, and a low-noise amplifier 400. The first resonant circuit 200 and the second resonant circuit 300 are arranged opposite each other. The receiving unit 100 includes capacitors C1, C2, and C3 for receiving magnetic resonance pulse signals transmitted by an external volume coil. One end of capacitor C3 is connected to one end of capacitor C1, and the other end of capacitor C3 is connected to one end of capacitor C2. The first resonant circuit 200 includes a resonant inductor L1, a resonant capacitor C5, and a diode D1. One end of the resonant inductor L1 is respectively connected to one end of the resonant capacitor C5 and the other end of capacitor C1. The other end of the resonant inductor L1 is respectively connected to one end of diode D1, the other end of diode D2, the other end of resonant capacitor C4, and the input end of the low-noise amplifier 400. The other end of the resonant capacitor C5 is respectively connected to the other end of diode D1, one end of diode D2, and the other end of resonant inductor L2, and then grounded. The second resonant circuit 300 includes a resonant inductor L2, a resonant capacitor C4, and a diode D2. One end of the resonant inductor L2 is connected to one end of the resonant capacitor C4 and the other end of the capacitor C2, respectively. The conduction direction of the diode D1 in the first resonant circuit 200 is opposite to the conduction direction of the diode D2 in the second resonant circuit 300. The low-noise amplifier 400 is connected to the receiving unit 100 via the first resonant circuit 200 and the second resonant circuit 300 and is used to adjust the signal-to-noise ratio of the local coil. When receiving the magnetic resonance pulse signal, the diode D1 in the first resonant circuit 200 or the diode D2 in the second resonant circuit 300 is turned on, depending on the positive or negative sign of the magnetic resonance pulse signal, to detune the local coil.

[0089] Here, other forms of local coils in the magnetic resonance imaging system are not given as examples.

[0090] The magnetic resonance imaging system provided by the present application achieves detuning of the local coil based on the positive or negative sign of the received magnetic resonance pulse signal without requiring additional active current signals for control, thereby simplifying the circuit, reducing production costs, and minimizing resource waste. The system also addresses the problem in related technologies of requiring active current signals to control detuning of the local coil, which complicates the circuit structure and wastes resources.

[0091] In some embodiments, the magnetic resonance imaging system further includes a volume coil; the volume coil is coupled to the local coil and is configured to transmit magnetic resonance pulse signals.

[0092] In some embodiments, the magnetic resonance imaging system further includes another local coil; the structure of the local coil can be the same as the structure of any local coil in the above embodiments.

[0093] For example, a local coil includes a receiving unit 100, a first resonant circuit 200, and a second resonant circuit 300. The first resonant circuit 200 and the second resonant circuit 300 are disposed opposite each other. The receiving unit 100 is connected to the first resonant circuit 200 and the second resonant circuit 300, respectively, to receive magnetic resonance pulse signals transmitted by an external volume coil. When receiving the magnetic resonance pulse signals, the diode D1 in the first resonant circuit 200 or the diode D2 in the second resonant circuit 300 is turned on, depending on the positive or negative sign of the magnetic resonance pulse signals, thereby detuning the local coil. Since the first or second resonant circuit is detuned, the local coil is also detuned. This decoupling is achieved between the local coils, thereby increasing the number of coils in the system.

[0094] It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit it. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0095] Obviously, the accompanying drawings are merely examples or embodiments of the present application. A person skilled in the art can also apply the present application to other similar situations based on these drawings without inventive effort. Furthermore, it is understandable that, although the work involved in this development process may be complex and lengthy, certain design, manufacturing, or production changes based on the technical content disclosed in this application are merely routine technical means for a person skilled in the art and should not be considered to constitute a deficiency in the disclosure of the present application.

[0096] The term "embodiment" as used in this application refers to specific features, structures, or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily mean that the embodiment is the same, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. It is understood, either explicitly or implicitly, by those skilled in the art that the embodiments described in this application can be combined with other embodiments when there is no conflict.

[0097] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A local coil, characterized in that: include: A receiving unit (100), a first resonant circuit (200), and a second resonant circuit (300); The first resonant circuit (200) and the second resonant circuit (300) are arranged opposite to each other; The receiving unit (100) is connected to the first resonant circuit (200) and the second resonant circuit (300) respectively, and is used to receive the magnetic resonance pulse signal emitted by the external volume coil; When receiving the magnetic resonance pulse signal, the diode D1 in the first resonant circuit (200) is turned on, or the diode D2 in the second resonant circuit (300) is turned on, depending on the positive or negative sign of the magnetic resonance pulse signal, so that the local coil is in a detuned state.

2. The local coil according to claim 1, characterized in that The first resonant circuit (200) comprises: a resonant inductor L1, a resonant capacitor C5 and a diode D1; One end of the resonant inductor L1 is connected to one end of the resonant capacitor C5 and the receiving unit (100), respectively; the other end of the resonant inductor L1 is connected to one end of the diode D1 and the second resonant circuit (300), respectively; The other end of the resonant capacitor C5 is connected to the other end of the diode D1 and the second resonant circuit (300) respectively and then grounded.

3. The local coil according to claim 1, wherein The second resonant circuit (300) comprises: a resonant inductor L2, a resonant capacitor C4 and a diode D2; One end of the resonant inductor L2 is connected to one end of the resonant capacitor C4 and the receiving unit (100), respectively; the other end of the resonant inductor L2 is connected to one end of the diode D2 and the first resonant circuit (200), respectively, and then grounded; The other end of the resonant capacitor C4 is connected to the other end of the diode D2 and the first resonant circuit (200) respectively.

4. The local coil according to claim 1, wherein The conducting direction of the diode D1 of the first resonant circuit (200) is opposite to the conducting direction of the diode D2 of the second resonant circuit (300).

5. The local coil according to claim 1, characterized in that The receiving unit (100) comprises: a capacitor C1, a capacitor C2 and a capacitor C3; One end of the capacitor C3 is connected to one end of the capacitor C1, and the other end of the capacitor C3 is connected to one end of the capacitor C2; The other end of the capacitor C1 is connected to the first resonant circuit (200); The other end of the capacitor C2 is connected to the second resonant circuit (300).

6. The local coil according to any one of claims 1 to 5, characterized in that Also included is a low noise amplifier (400); The low noise amplifier (400) is connected to the receiving unit (100) via the first resonant circuit (200) and the second resonant circuit (300), and is used to adjust the signal-to-noise ratio of the local coil.

7. The local coil according to claim 6, characterized in that The resonant inductor L1 and the resonant capacitor C5 in the first resonant circuit (200) and the resonant inductor L2 and the resonant capacitor C4 in the second resonant circuit (300) form an impedance conversion circuit for converting the input impedance of the low-noise amplifier (400).

8. The local coil according to claim 6, characterized in that The input impedance of the low noise amplifier (400) is less than 2 ohms.

9. A magnetic resonance imaging system, characterized in that: The method comprises the local coil according to any one of claims 1 to 8.

10. The magnetic resonance imaging system according to claim 9, wherein Also included is a volume coil; The volume coil is coupled to the local coil and is used to transmit magnetic resonance pulse signals.

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