Magnetic resonance passive high-impedance imaging gain system

Abstract

The present invention relates to a magnetic resonance passive high-impedance imaging gain system. A transmitting coil is used to transmit a magnetic resonance signal to a target site to be imaged, and a receiving coil is used to receive an electromagnetic signal returned from the target site to be imaged. At a target location to be imaged, a passive high-impedance gain coil is disposed, a single-channel high-impedance coil being in parallel connection with a resonant circuit and a detuning circuit, and the single-channel high-impedance coil being used to limit the flow of internal current. When a magnetic resonance signal is received, both the resonant circuit and the detuning circuit operate simultaneously. Due to the effect of the detuning circuit, the passive high-impedance gain coil does not affect the magnetic resonance signal at this time. Meanwhile, when an electromagnetic signal is received, only the resonant circuit operates in the circuit. Under the action of the resonant circuit, the passive high-impedance gain coil enters a resonant state, thereby enhancing the electromagnetic signal. The magnetic resonance passive high-impedance imaging gain system disclosed in the present application can achieve the objective of improving imaging quality.

Description

A passive high-impedance imaging gain system for magnetic resonance Technical Field

[0001] This invention relates to the field of magnetic resonance imaging technology, and in particular to a passive high-impedance magnetic resonance imaging gain system. Background Technology

[0002] Magnetic resonance imaging (MRI), as an advanced medical imaging technique, is widely used in clinical diagnosis and biomedical research due to its ability to provide high-resolution soft tissue images. MRI technology relies on strong magnetic fields and radio frequency (RF) pulses to excite hydrogen nuclei within the body, and then detects the signals generated during their relaxation process. With the advancement of medical technology, MRI has seen significant improvements in imaging speed, resolution, and contrast.

[0003] However, while existing MRI technology plays a vital role in medical imaging, it still suffers from several significant limitations. The copper strip phased array coils used in traditional MRI systems often struggle to achieve ideal fit when adapting to complex and curved areas of human anatomy, particularly joints, leading to reduced signal reception efficiency. Furthermore, these coils require precise electromagnetic balance to minimize induced coupling, which not only increases design and debugging complexity but also limits their versatility. During dynamic imaging, even minor patient movements can cause image artifacts, affecting image quality, and existing coils are insufficient for handling such dynamic imaging. With increasing demands for image quality, especially in dynamic imaging and imaging of highly curved anatomical structures, current technology can no longer meet the growing clinical needs. Summary of the Invention

[0004] To address the limitations of MRI technology in imaging highly curved anatomical structures, this invention proposes a passive high-impedance imaging gain system for magnetic resonance imaging.

[0005] The technical solution adopted in this invention is a magnetic resonance passive high impedance imaging gain system, which includes a transmitting coil for transmitting magnetic resonance signals to the target area to be imaged and a picking coil for receiving electromagnetic signals, wherein a passive high impedance gain coil is provided at the target area to be imaged.

[0006] The passive high-impedance gain coil includes a single-channel high-impedance coil, which is connected in parallel with a resonant circuit and a detuning circuit. When the passive high-impedance gain coil receives a magnetic resonance signal, the resonant circuit and the detuning circuit operate simultaneously to put the passive high-impedance gain coil in a detuned state. When the passive high-impedance coil receives an electromagnetic signal, only the resonant circuit operates to put the passive high-impedance gain coil in a resonant state.

[0007] Preferably, the detuned circuit is a bidirectional diode.

[0008] Preferably, the detuning circuit includes two bidirectional diode units, and the two bidirectional diode units are connected in series and then connected in parallel with the single-channel high-impedance coil and the resonant circuit.

[0009] Preferably, the resonant circuit is an LC parallel resonant circuit.

[0010] Preferably, at least two passive high-impedance gain coils are provided, and the plurality of passive high-impedance gain coils surround the target area to be imaged in a manner covering a 360° range.

[0011] Preferably, any two adjacent passive high-impedance gain coils may be placed overlappingly or not overlappingly.

[0012] Preferably, any two adjacent passive high-impedance gain coils are spaced at the same angle around the position of the target to be imaged.

[0013] Preferably, the single-channel high-impedance coil has deformation capability to conform to the target area to be imaged and to dynamically and synchronously deform in accordance with the target area to be imaged.

[0014] Preferably, the resistance of the single-channel high-impedance coil is not less than 300 ohms.

[0015] Preferably, the single-channel resistor coil is a coaxial cable.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This application discloses a passive high-impedance magnetic resonance imaging gain system. A transmitting coil emits a magnetic resonance signal to the target area, and a pickup coil receives the electromagnetic signal returned from the target area. A passive high-impedance gain coil is located at the target area, wherein a single-channel high-impedance coil is connected in parallel with a resonant circuit and a detuned circuit, and the single-channel high-impedance coil is used to limit the flow of internal current. When a magnetic resonance signal is received, the resonant circuit and the detuned circuit operate simultaneously. Due to the effect of the detuned circuit, the passive high-impedance gain coil does not affect the magnetic resonance signal at this time. However, when an electromagnetic signal is received, only the resonant circuit operates in the circuit. Due to the effect of the resonant circuit, the passive high-impedance gain coil is in a resonant state, thereby amplifying the electromagnetic signal. Due to the special structure of this passive high-impedance gain coil, it can operate independently of other components in the passive high-impedance magnetic resonance imaging gain system, without needing to be connected to other components and thus not being limited by them, making its application scenarios wider. Furthermore, because the passive high-impedance gain coil has a high-impedance structure, its changes due to coupling and bending are not significant. Therefore, the passive high-impedance imaging gain system of magnetic resonance can significantly enhance the reception of electromagnetic signals, and at the same time solve the limitations of traditional MRI systems in adapting to the complex curves of the human body, such as joints. It not only improves the signal reception efficiency, but also ensures stable operation in highly curved anatomical areas.

[0018] Compared with the prior art, the magnetic resonance passive high impedance imaging gain system disclosed in this application can achieve the goal of improving imaging quality. Attached Figure Description

[0019] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:

[0020] Figure 1 shows a physical diagram and circuit diagram of an embodiment of a passive high impedance gain coil in a magnetic resonance passive high impedance imaging gain system according to an embodiment of the present invention.

[0021] Figure 2 shows a Smith chart according to the embodiment provided in Figure 1;

[0022] Figure 3 shows a schematic diagram of the resonant frequencies under the bending angle state and the normal state according to the embodiment provided in Figure 1, where (a) is the relative placement position and (b) is the change of two resonant frequencies compared with each other.

[0023] Figure 4 shows the measured resonant frequency variation of two adjacent passive high-impedance gain coils at different distances according to the embodiment provided in Figure 1;

[0024] Figure 5 shows a comparison of the signal-to-noise ratio (SNR) when using the BC body coil to receive signals and when using the knee coil to receive signals, as well as when using a passive high-impedance gain coil in the embodiment provided in Figure 1. (a) and (c) are relative placement positions. (b) and (d) show that the signal is significantly improved when the passive high-impedance gain coil is used in combination with other coils in different situations. The comparison of the SNR values ​​at the positions shown in the right figure is as follows.

[0025] Figure 6 shows a comparison of imaging at the ankle position using a combination of four-channel passive high-impedance gain coils and knee coils, and imaging using only the knee coils, based on a magnetic resonance high-impedance coil array provided in Figure 1. (a) Relative placement positions, (b)(d) Imaging using only the knee coils, (c)(e) Imaging effect of using the passive high-impedance gain coil array with knee coils.

[0026] Figure 7 shows a comparison of imaging at the knee position using a magnetic resonance high impedance coil array according to Figure 1, with the combination of a 4-channel passive high impedance gain coil and a knee coil, and with imaging using only the knee coil. (a) Relative placement positions, (b)(d) Imaging using only the knee coil, (c)(e) Imaging effect of using the passive high impedance gain coil array with the knee coil.

[0027] Figure 8 shows a flowchart of the use of a magnetic resonance passive high impedance imaging gain system provided according to an embodiment of the present invention;

[0028] Figure 9 shows a signal-to-noise ratio comparison diagram of a magnetic resonance high-impedance coil array in water film imaging according to Figure 1, (a) relative placement position, (b) imaging using only the knee coil, and (c) imaging effect diagram of the knee coil combined with a passive high-impedance gain coil array. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0030] This invention discloses a passive high-impedance imaging gain system for magnetic resonance imaging. Please refer to Figures 1 to 5. It includes a transmitting coil for transmitting magnetic resonance signals to the target area to be imaged and a picking coil for receiving electromagnetic signals. A passive high-impedance gain coil is provided at the target area to be imaged.

[0031] The passive high-impedance gain coil includes a single-channel high-impedance coil, which is connected in parallel with a resonant circuit and a detuning circuit. When the passive high-impedance gain coil receives a magnetic resonance signal, the resonant circuit and the detuning circuit operate simultaneously to put the passive high-impedance gain coil in a detuned state. When the passive high-impedance coil receives an electromagnetic signal, only the resonant circuit operates to put the passive high-impedance gain coil in a resonant state.

[0032] The transmitting coil emits a magnetic resonance signal to the target area, while the picking coil receives the electromagnetic signal returned from the target area. A passive high-impedance gain coil is located at the target location. This single-channel high-impedance coil is connected in parallel with both the resonant and detuned circuits, limiting the flow of internal current. When a magnetic resonance signal is received, both the resonant and detuned circuits operate simultaneously. Due to the detuned circuit, the passive high-impedance gain coil does not affect the magnetic resonance signal. However, when an electromagnetic signal is received, only the resonant circuit operates. Because of the resonant circuit, the passive high-impedance gain coil is in a resonant state, thus amplifying the electromagnetic signal.

[0033] It is important to note that due to the unique structure of this passive high-impedance gain coil, it can operate independently of other components in a passive high-impedance magnetic resonance imaging gain system. It does not require connection to other components and is not limited by them, thus broadening its application scenarios. Furthermore, because the passive high-impedance gain coil has a high-impedance structure, its sensitivity to coupling and bending changes is not significant. Therefore, the passive high-impedance magnetic resonance imaging gain system can significantly enhance electromagnetic signal reception while overcoming the limitations of traditional MRI systems in adapting to complex curves of the human body, such as joints. It not only improves signal reception efficiency but also ensures stable operation in highly curved anatomical regions. Compared to existing technologies, the passive high-impedance magnetic resonance imaging gain system disclosed in this application can achieve the goal of improving imaging quality.

[0034] Traditional phased array coils in MRI systems are typically made of copper strips. These coils operate based on the principle of electromagnetic induction; when an alternating magnetic field passes through the coil, an induced electromotive force (EMF) is generated, thus detecting the MRI signal. In multi-channel phased array coils, due to the close proximity of the coils, when current flows through one coil, a magnetic field is generated. This magnetic field may induce an EMF in adjacent coils; this phenomenon is called inductive coupling. If left uncontrolled, the magnetic field generated by a change in current in one coil may interfere with the normal detection of MRI signals by adjacent coils, leading to signal distortion. To avoid the impact of this inductive coupling on image quality, the electromagnetic characteristics of each coil need to be precisely adjusted to minimize their mutual influence, i.e., to achieve precise electromagnetic balance. This typically requires a complex design and debugging process. Moreover, in practical use, the influence on phased array coils is not limited to the interaction between adjacent coils; the transmitting coil, the picking coil, and even the electrical wiring harnesses can all exert inductive effects. This necessitates extremely complex algorithm design and equipment placement planning for imaging.

[0035] Furthermore, phased array coils made of copper strips are relatively rigid and difficult to fully conform to complex, curved areas, such as the knee joint. The irregular shape of the joint changes during movement, and traditional copper strip coils cannot adaptively adjust to the joint's shape and movement, resulting in insufficient contact between the coil and the body surface. Moreover, because the coil cannot conform well to the complex curves of the body, the distance between the coil and different locations is inconsistent when receiving MRI signals, leading to uneven signal reception. That is, at the bend of the joint, the distance from the coil may be greater, resulting in a weaker signal, while other locations with better contact with the coil may receive a stronger signal, affecting the quality and accuracy of the imaging.

[0036] The proposed solution employs a wireless connection, eliminating the direct electrical connection to the MRI system. This not only reduces the inconvenience and potential interference caused by the connection but also simplifies the coil integration process, potentially lowering costs. Firstly, without the constraints of cables, it can be placed more freely at the imaging site, whether it's a curved part of the body or a hard-to-reach area, allowing for easier operation. For example, when imaging joints, the wireless coil can flexibly adjust its position according to the joint's movement and shape changes, improving imaging convenience and accuracy. Secondly, the electrical connection of wired coils can introduce various interferences. For instance, cables may be affected by surrounding electromagnetic fields, generating induced currents. These induced currents can interfere with the coil's normal reception and detection of MRI signals, resulting in artifacts in the image. The wireless coil transmits signals wirelessly, avoiding this interference caused by electrical connections. During the imaging process, if the connecting cable of the wired coil moves, for example, due to the patient's unintentional movement causing the cable to shake, this movement of the cable will change the electromagnetic environment of the coil, thereby affecting signal reception and detection and producing artifacts in the image. Since the wireless coil has no cable, there will be no artifacts caused by cable movement, providing a more stable imaging environment and further improving image quality.

[0037] More importantly, by using high-impedance materials and designs, the mutual induction between adjacent elements is reduced. High impedance means a greater resistance to current flow, limiting the current flow between adjacent components, thereby reducing signal loss and distortion. This is especially important for multi-channel MRI systems, improving the accuracy and efficiency of signal reception. Because the high-impedance design reduces the mutual induction between adjacent elements, the requirements for precise electromagnetic balance are relatively lower. This simplifies the coil design and debugging process, improving the coil's versatility and ease of use. The "adjacent elements" here include the induced effects between adjacent coils, the induced effects of the transmitting and picking coils, and even the induced effects caused by other electrical wiring harnesses, thus greatly improving imaging accuracy. Conversely, it also reduces the requirements for equipment layout and algorithm design during imaging.

[0038] Figure 5 shows a comparison of the signal-to-noise ratio (SNR) when using the BC body coil to receive signals, when using the knee coil to receive signals, and when using a passive high-impedance gain coil. (a) and (c) show the relative placement positions. (b) and (d) show the significant signal improvement when the passive high-impedance gain coil is used in combination with other coils under different conditions. The comparison of the SNR values ​​is shown in the right figure.

[0039] This application demonstrates outstanding signal enhancement, particularly in ankle and knee joint imaging, showcasing its potential for improving image quality. The multi-channel configuration of the passive high-impedance gain coil supports more advanced imaging techniques, such as parallel imaging, further enhancing imaging speed and quality. Special attention was paid to the versatility and compatibility of the MRI passive high-impedance imaging gain system during the design process, ensuring easy integration into different MRI devices while guaranteeing its safety and biocompatibility to meet clinical requirements.

[0040] The magnetic resonance passive high impedance imaging gain system disclosed in this invention has the advantage that, due to the high impedance characteristics of the passive high impedance gain coil itself, there are no special requirements for bending or relative placement distance during use. Furthermore, since the passive high impedance gain coil itself is flexible, not only is there no need for special design of the relative placement of the passive high impedance gain coils when using the passive high impedance gain coil array, but it can also be bent at large angles during use. Under these conditions, the present invention can still perform magnetic resonance signal enhancement in a relatively stable state.

[0041] In the aforementioned techniques, impedance refers to the resistance to the flow of electric current. It is a complex number comprising two parts: resistance and reactance, usually represented by the symbol Z, and its unit is ohms (Ω).

[0042] Resistance: Resistance is the opposition to the flow of electric current. It is determined by factors such as the conductor's material, length, cross-sectional area, and temperature, and follows Ohm's law, which states that current equals voltage divided by resistance (I = V / R). In this technology, the properties of the coil material will affect its resistance value.

[0043] Reactance Section: Inductive Reactance (Inductive Reactance): When current flows through a coil, a self-induced electromotive force (EMF) is generated due to electromagnetic induction. This self-induced EMF opposes the change in current; this opposition is called inductive reactance. The magnitude of inductive reactance is related to the inductance (L) of the coil and the frequency (f) of the current, and its calculation formula is XL = 2πfL. In the aforementioned wearable wireless high-impedance array technology, the design of the coil's inductance affects its inductive reactance, and thus affects the overall impedance.

[0044] Capacitive reactance (capacitive reactance): In circuits containing capacitors, the capacitors impede the flow of alternating current, a phenomenon known as capacitive reactance. The magnitude of capacitive reactance depends on the capacitance (C) and the frequency (f) of the current, and is calculated using the formula XC = 1 / (2πfC). In the circuit design of this technology, the relevant parameters of the capacitor will affect the capacitive reactance, thereby affecting the overall impedance.

[0045] Figure 8 is a flowchart of an imaging method for a passive high-impedance imaging gain system based on the present invention. The imaging method includes the following steps:

[0046] Step S1: Determine the target area to be imaged. First, cover the target area to be imaged with a passive high-impedance gain coil, and then select the receiving (transmitting and picking up) coil to be used with the target area to be imaged.

[0047] Step S2, then place the target part to be imaged, which has been attached to the passive high impedance gain coil, into the receiving (transmitting and picking up) coil that matches the selected target part to be imaged;

[0048] Step S3: The hospital bed is placed into the main magnet for scanning.

[0049] Step S4: End the inspection. Remove the receiver (transmitter / pickup integrated) coil and the passive wireless high-impedance coil in sequence, and put them back into the locker. The scan is now complete.

[0050] In general, when the passive high-impedance imaging gain system for magnetic resonance is working, the magnetic resonance signal is transmitted through the transmitting coil. At this time, the passive high-impedance gain coil will not affect the magnetic resonance signal. The tissue of the patient's imaging site is excited and emits an electromagnetic signal. This electromagnetic signal is amplified when it passes through the passive high-impedance gain coil. The amplified signal is transmitted to the universal pickup coil 4 through magnetic coupling to complete the signal acquisition.

[0051] In some embodiments, as shown in part b of FIG1, the detuning circuit is a bidirectional diode.

[0052] The detuning circuit is a bidirectional diode unit composed of two reverse-biased diodes connected in parallel. Compared with other detuning circuits, the bidirectional diode unit has a simpler structure, lower cost, and more reliable performance. In other embodiments, the detuning circuit can also be achieved by introducing a new detuning loop or other detuning methods, thereby achieving a similar detuning effect to the bidirectional diode unit.

[0053] In some specific embodiments, the detuning circuit includes two bidirectional diode units, and the two bidirectional diode units are connected in series and then connected in parallel with the single-channel high-impedance coil and the resonant circuit.

[0054] Specifically, after two bidirectional diode units are connected in series, they are then connected in parallel with a single-channel high-impedance coil and a resonant circuit. By setting up two sets of bidirectional diode units, the passive high-impedance gain coil can have higher robustness. If one bidirectional diode unit fails to work, the other bidirectional diode unit can still continue to work.

[0055] In some embodiments, the resonant circuit is an LC parallel resonant circuit.

[0056] Specifically, the LC parallel resonant circuit has a simple structure and low cost. By selecting the capacitor and inductor, it can achieve a high resistance value at the excitation frequency and can select the resonant frequency to meet the requirements of enhancing electromagnetic signals.

[0057] The LC parallel resonant circuit is composed of a capacitor and an inductor connected in parallel. It is not limited to having only two electronic devices, capacitor and inductor. In other embodiments, if other electronic devices are added without changing the main function of the LC parallel resonant circuit, it should still be considered as the LC parallel resonant circuit described in this application.

[0058] In some embodiments, at least two passive high-impedance gain coils are provided, and a plurality of passive high-impedance gain coils surround the target area to be imaged in a manner covering a 360° range.

[0059] The magnetic resonance passive high-impedance imaging gain system has at least two passive high-impedance gain coils, enabling the magnetic resonance high-impedance coil array to enhance the detection site at multiple locations without inductive coupling during dynamic imaging, thus preventing image artifacts when the patient moves. This invention aims to maintain optimal performance during dynamic body movement, reduce motion artifacts, and improve image quality. By utilizing wireless technology and high-impedance design, signal transmission and reception efficiency are improved, thereby enhancing the overall performance of the MRI system. Simultaneously, innovative design reduces coil manufacturing and integration costs, simplifies integration with the MRI system, and improves economy and accessibility. Specifically, the magnetic resonance high-impedance coil array disclosed in this application has no requirements on placement or bending angle and can be used in conjunction with different types of commercially available receiving coils, such as knee coils or head coils, thereby improving the signal-to-noise ratio without introducing additional images into the final image.

[0060] Please refer to Figures 6, 7 and 9. Figure 6 is a comparison of imaging using a magnetic resonance high impedance coil array at the ankle position with a combination of four-channel passive high impedance gain coils and knee coils and imaging using only the knee coils. (a) Relative placement positions, (b)(d) Imaging using only the knee coils, (c)(e) Imaging effect of using the passive high impedance gain coil array with knee coils.

[0061] Figure 7 is a comparison of imaging at the knee position using a magnetic resonance high impedance coil array with a combination of 4-channel passive high impedance gain coils and knee coils and imaging using only the knee coils. (a) Relative placement positions, (b)(d) Imaging using only the knee coils, (c)(e) Imaging effect of using the passive high impedance gain coil array with knee coils.

[0062] Figure 8 is a comparison of the signal-to-noise ratio of a magnetic resonance high-impedance coil array in water film imaging. (a) Relative placement positions, (b) Imaging using only the knee coil, and (c) Imaging effect of using the knee coil in combination with a passive high-impedance gain coil array.

[0063] The feasibility of this application has been verified by experiments. During the water model test, a nearly 100% improvement in signal-to-noise ratio on the surface can be clearly seen. In human body imaging, we can see that the signal-to-noise ratio on the surface is improved by up to 50% when imaging the ankle joint, and the signal-to-noise ratio is improved by nearly 20% when imaging the knee.

[0064] In some specific embodiments, any two adjacent passive high-impedance gain coils can be placed overlappingly or not overlappingly. That is, this solution does not have high requirements for the placement of two adjacent passive high-impedance gain coils, and the spacing can be set relatively arbitrarily. Even if they overlap, the impact on imaging is very weak.

[0065] In some specific embodiments, any two adjacent passive high-impedance gain coils are spaced at the same angle around the target location. For example, in a four-channel or six-channel design, four or six passive high-impedance gain coils are evenly distributed circumferentially at the body part to be imaged.

[0066] In some embodiments, the single-channel high-impedance coil has a deformation capability to conform to the target area to be imaged and to generate deformation synchronously with the dynamic changes of the target area to be imaged.

[0067] It should be noted that the single-channel high-impedance coil has deformation capability, allowing the passive high-impedance gain coil to maintain a certain shape without the need for external fixing structures. It can also adapt to external motion changes, undergoing bending and other deformations to maintain consistent imaging of the target. This deformation capability allows the coil to better adapt to dynamic changes in the human body, achieving more uniform signal reception and improving image quality in both static and dynamic imaging processes.

[0068] In some embodiments, the resistance of the single-channel high-impedance coil is not less than 300 ohms.

[0069] It should be noted that the impedance of a single-channel high-impedance coil is not less than 300 ohms, which is the high impedance described in this application. Specifically, a single-channel high-impedance coil refers to an inductor coil in which current can only flow along a single path and presents a high impedance to AC signals.

[0070] In some embodiments, the single-channel resistor coil is a coaxial cable.

[0071] Coaxial cable is a type of cable used to transmit electrical signals, its structure resembling a concentric cylinder. A typical coaxial cable consists of four main parts: **Center Conductor:** A single metal wire, usually copper or aluminum, responsible for transmitting the signal. The signal current flows through the center conductor. **Insulation Layer:** An insulating material surrounding the center conductor, typically made of polyethylene (PE) or polytetrafluoroethylene (PTFE), used to isolate the center conductor from the outer conductor, preventing signal leakage or interference. **Outer Conductor:** A metal conductor surrounding the insulation layer, usually an aluminum foil layer or copper mesh, which acts as a shield during signal transmission, reducing the impact of external interference on the signal. **Outer Sheath:** An external protective layer surrounding the outer conductor, typically made of polyvinyl chloride (PVC) or polyethylene chloride (PE), providing waterproofing, insulation, and protection.

[0072] In some embodiments, the pickup coil surrounds the passive high-impedance gain coil in a manner covering a 360° range.

[0073] In some embodiments, a covering unit is provided between the passive high-impedance gain coil and the target area to be imaged.

[0074] Specifically, the covering unit, such as a compliant membrane, can prevent the single-channel high-impedance coil from directly contacting the skin, thereby affecting the normal use of the passive high-impedance gain coil. Preferably, the single-channel high-impedance coil is covered with a covering unit, which facilitates placement and operation by the operator and further protects the passive high-impedance gain coil.

[0075] In some embodiments, the resonant circuit and the detuning circuit are both located at the same position on the single-channel high-impedance coil, thereby facilitating replacement and repair in the event of damage to the resonant circuit and the detuning circuit.

[0076] In the description of this specification, the use of terms such as "Embodiment 1," "this embodiment," or "in one embodiment" indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example; moreover, the specific features, structures, materials, or characteristics described may be combined in any appropriate manner in one or more embodiments or examples.

[0077] In the description of this specification, the terms "connection," "installation," "fixing," "setting," and "having" are interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0078] In the description of this specification, relational terms such as “first” and “second” are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0079] The above description of the embodiments is intended to enable those skilled in the art to understand and apply the technology of this invention. Those skilled in the art can easily make various modifications to these examples and apply the general principles described herein to other embodiments without creative effort. Therefore, this invention is not limited to the above embodiments. Modifications in the following situations should be within the scope of protection of this invention: ① New technical solutions implemented based on the technical solution of this invention and combined with existing common knowledge, where the technical effects of the new technical solution do not exceed the technical effects of this invention; ② Equivalent substitutions of some features of the technical solution of this invention using known technology, resulting in the same technical effects as those of this invention; ③ Extendable technical solutions based on the technical solution of this invention, where the substantive content of the extended technical solution does not exceed the technical solution of this invention; ④ Equivalent transformations made using the content of this specification and drawings, directly or indirectly applied to other related technical fields.

Claims

1. A passive high-impedance magnetic resonance imaging gain system, comprising a transmitting coil for emitting magnetic resonance signals to a target region and a picking coil for receiving electromagnetic signals, characterized in that, A passive high-impedance gain coil is provided at the target location to be imaged; The passive high-impedance gain coil includes a single-channel high-impedance coil, which is connected in parallel with a resonant circuit and a detuning circuit. When the passive high-impedance gain coil receives a magnetic resonance signal, the resonant circuit and the detuning circuit operate simultaneously to put the passive high-impedance gain coil in a detuned state. When the passive high-impedance coil receives an electromagnetic signal, only the resonant circuit operates to put the passive high-impedance gain coil in a resonant state.

2. The magnetic resonance passive high-impedance imaging gain system according to claim 1, characterized in that, The detuned circuit is a bidirectional diode unit.

3. The magnetic resonance passive high-impedance imaging gain system according to claim 2, characterized in that, The detuned circuit includes two bidirectional diode units, and the two bidirectional diode units are connected in series and then connected in parallel with the single-channel high-impedance coil and the resonant circuit.

4. The magnetic resonance passive high-impedance imaging gain system according to claim 1, characterized in that, The resonant circuit is an LC parallel resonant circuit.

5. A passive high-impedance imaging gain system for magnetic resonance according to claim 1, characterized in that, At least two passive high-impedance gain coils are provided, and multiple passive high-impedance gain coils surround the target area to be imaged in a manner covering a 360° range.

6. A passive high-impedance imaging gain system for magnetic resonance according to claim 5, characterized in that, Any two adjacent passive high-impedance gain coils may be placed overlappingly or not overlappingly.

7. A passive high-impedance imaging gain system for magnetic resonance according to claim 5, characterized in that, Any two adjacent passive high-impedance gain coils are spaced at the same angle around the position of the target to be imaged.

8. A passive high-impedance imaging gain system for magnetic resonance according to claim 1, characterized in that, The single-channel high-impedance coil has deformation capability to conform to the target area to be imaged and to dynamically and synchronously deform in accordance with the target area to be imaged.

9. A passive high-impedance imaging gain system for magnetic resonance according to any one of claims 1 to 8, characterized in that, The resistance of the single-channel high-impedance coil is not less than 300 ohms.

10. A magnetic resonance passive high-impedance imaging gain system according to any one of claims 1 to 8, characterized in that, The single-channel resistor coil is a coaxial cable.

Images