Magnetic resonance passive high-impedance imaging gain system

Abstract

The invention relates to a magnetic resonance passive high-impedance imaging gain system, a transmitting coil is used for transmitting a magnetic resonance signal to a to-be-imaged target part, and a pickup coil is used for receiving an electromagnetic signal returned by the to-be-imaged target part. A passive high-impedance gain coil is arranged at the position of a target to be imaged, the single-channel high-impedance coil is connected with the resonance circuit and the detuning circuit in parallel, and the single-channel high-impedance coil is used for limiting flowing of internal current. When a magnetic resonance signal is received, the resonance circuit and the detuning circuit operate at the same time, and under the action of the detuning circuit, the passive high-impedance gain coil does not affect the magnetic resonance signal at the moment; when the electromagnetic signal is received, only the resonance circuit operates in the circuit, and due to the effect of the resonance circuit, the passive high-impedance gain coil is in a resonance state at the moment, so that the effect of enhancing the electromagnetic signal is achieved. According to the magnetic resonance passive high-impedance imaging gain system disclosed by the invention, the purpose of improving the imaging quality requirement can be achieved.

Description

Technical Field

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

[0002] Magnetic resonance imaging (MRI), as an advanced medical imaging technology, is widely used in clinical diagnosis and biomedical research because it can provide high-resolution soft tissue images. MRI technology relies on strong magnetic fields and radio frequency (RF) pulses to excite hydrogen nuclei in the body and then detect the signals generated during their relaxation process. With the development of medical technology, MRI has significantly improved in imaging speed, resolution and contrast.

[0003] However, existing MRI technology, despite its important position in the field of medical imaging, still has some significant limitations. The copper tape phased array coils used in traditional MRI systems often have difficulty achieving an ideal fit when adapting to complex and curved areas of human anatomy, especially in joints, resulting in reduced signal reception efficiency. In addition, these coils require precise electromagnetic balance to minimize inductive coupling, which not only increases the complexity of design and debugging, but also limits the versatility of the coils. During dynamic imaging, slight movements of the patient may cause image artifacts and affect imaging quality, and the performance of existing coils in handling this type of dynamic imaging is still insufficient. With the increasing requirements for imaging quality, especially in dynamic imaging and imaging of highly curved anatomical structures, existing technologies can no longer meet the growing clinical needs. Summary of the invention

[0004] In order to solve the defects of MRI technology in imaging highly curved anatomical structures, the present invention proposes a magnetic resonance passive high impedance imaging gain system.

[0005] The technical solution adopted by the present invention is a magnetic resonance passive high impedance imaging gain system, comprising a transmitting coil for transmitting magnetic resonance signals to a target part to be imaged and a pickup coil for receiving electromagnetic signals, wherein a passive high impedance gain coil is provided at the target part to be imaged;

[0006] The passive high-impedance gain coil includes a single-channel high-impedance coil, and the single-channel high-impedance coil 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 detuning circuit is a bidirectional diode.

[0008] Preferably, the detuning circuit comprises 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 part to be imaged in a manner of covering a 360° range.

[0011] Preferably, any two adjacent passive high-impedance gain coils may be placed overlappingly or non-overlappingly.

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

[0013] Preferably, the single-channel high-impedance coil has a deformation capability to fit the target part to be imaged and deform synchronously with the dynamics of the target part 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 resistance coil is a coaxial cable.

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

[0017] The present application discloses a magnetic resonance passive high impedance imaging gain system, wherein the transmitting coil is used to transmit a magnetic resonance signal to the target part to be imaged, and the pickup coil is used to receive the electromagnetic signal returned by the target part to be imaged. A passive high impedance gain coil is provided at the target position to be imaged, wherein the single-channel high impedance coil is connected in parallel with the resonant circuit and the detuned circuit, and the single-channel high impedance coil is used to limit the flow of internal current. When the 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; and when the 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 at this time, thereby enhancing the electromagnetic signal. Due to the special structure of the passive high impedance gain coil, it can be independent of other components in the magnetic resonance passive high impedance imaging gain system, does not need to be connected to other components and is not restricted by other components, and has a wider range of usage scenarios. In addition, since the passive high impedance gain coil is a high impedance structure, the changes in coupling and bending itself are not obvious. Therefore, the passive high-impedance magnetic resonance imaging gain system can significantly enhance the reception of electromagnetic signals, while solving the limitations of traditional MRI systems in adapting to 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 the present application can achieve the purpose of improving the imaging quality requirements. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0020] Figure 1 A physical diagram and a circuit diagram of an embodiment of a passive high-impedance gain coil in a magnetic resonance passive high-impedance imaging gain system provided by an embodiment of the present invention are shown;

[0021] Figure 2 Shown according to Figure 1 Smith chart of the provided embodiments;

[0022] Figure 3 Shown according to Figure 1 Schematic diagram of the resonance frequency of the provided embodiment in the bending angle state and the normal state, wherein (a) is the relative placement position and (b) is the change of two resonance frequencies compared with each other;

[0023] Figure 4 Shown according to Figure 1 The measured resonant frequency changes of two adjacent passive high impedance gain coils of the provided embodiment at different distances;

[0024] Figure 5 Shown according to Figure 1 The signal-to-noise ratio comparison diagrams of the embodiments provided when using the BC body coil to receive signals and the knee coil to receive signals and when using a passive high-impedance gain coil in combination are shown in the figure on the right. (a) (c) Relative placement positions. (b) (d) When the passive high-impedance gain coil and other coils are used in combination in different situations, the signal is significantly improved. The comparison diagrams of the signal-to-noise ratio size in the positions shown in the figure on the right are shown in the figure on the right.

[0025] Figure 6 Shown according to Figure 1 A comparison diagram of a magnetic resonance high impedance coil array provided at the ankle position using a four-channel passive high impedance gain coil and a knee coil in combination and using only the knee coil for imaging, (a) relative placement, (b)(d) images of imaging using only the knee coil, (c)(e) images of the imaging effect of the knee coil combined with the passive high impedance gain coil array;

[0026] Figure 7 Shown according to Figure 1 A comparison diagram of a magnetic resonance high impedance coil array provided at the knee position using a 4-channel passive high impedance gain coil and a knee coil in combination and using only the knee coil for imaging, (a) relative placement, (b)(d) images of imaging using only the knee coil, (c)(e) images of the imaging effect of the knee coil combined with the passive high impedance gain coil array;

[0027] Figure 8 A flowchart of using a magnetic resonance passive high impedance imaging gain system provided by an embodiment of the present invention is shown;

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

[0029] In order to make the purpose, technical scheme and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Examples of embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar components or components with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0030] The present invention discloses a magnetic resonance passive high impedance imaging gain system, please refer to Figures 1 to 5 , comprising a transmitting coil for transmitting magnetic resonance signals to a target part to be imaged and a pickup coil for receiving electromagnetic signals, wherein a passive high impedance gain coil is provided at the target part to be imaged;

[0031] The passive high-impedance gain coil includes a single-channel high-impedance coil, and the single-channel high-impedance coil 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 is used to transmit magnetic resonance signals to the target part to be imaged, and the pickup coil is used to receive electromagnetic signals returned by the target part to be imaged. A passive high-impedance gain coil is provided at the target position to be imaged, wherein a single-channel high-impedance coil is connected in parallel with the resonant circuit and the detuned circuit, and the single-channel high-impedance coil is used to limit the flow of internal current. When the 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; while when the 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 at this time, thereby enhancing the electromagnetic signal.

[0033] It should be emphasized that due to the special structure of the passive high-impedance gain coil, it can be independent of other components in the magnetic resonance passive high-impedance imaging gain system, does not need to be connected to other components and is not restricted by other components, and has a wider range of usage scenarios. Because the passive high-impedance gain coil is a high-impedance structure, the changes in coupling and bending are not obvious. Therefore, the magnetic resonance passive high-impedance imaging gain system can significantly enhance the reception of electromagnetic signals, while solving the limitations of traditional MRI systems in adapting to 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. Compared with the prior art, a magnetic resonance passive high-impedance imaging gain system disclosed in the present application can achieve the purpose of improving imaging quality requirements.

[0034] The phased array coils in traditional MRI systems are usually made of copper strips. This type of coil works based on the principle of electromagnetic induction. When an alternating magnetic field passes through the coil, an induced electromotive force is generated in the coil, thereby detecting the MRI signal. In a multi-channel phased array coil, since the distance between the coils is close, when a current passes through one of the coils, a magnetic field is generated. This magnetic field may generate an induced electromotive force in the adjacent coil. This phenomenon is called inductive coupling. If not controlled, the magnetic field generated by the current change in one coil may interfere with the normal detection of MRI signals by the adjacent coil, resulting in signal distortion. In order to avoid the impact of this inductive coupling on the imaging quality, it is necessary to accurately adjust the electromagnetic characteristics of each coil to minimize the mutual influence between them, that is, to achieve precise electromagnetic balance. This usually requires a complex design and debugging process. Moreover, in actual use, the phased array coil is affected not only by the adjacent coils, but also by the transmitting coil, the pickup coil, and even the wiring harness of the electrical connection. This requires extremely complex algorithm design and equipment location planning for imaging.

[0035] In addition, the phased array coil made of copper tape is relatively hard and difficult to fully fit these complex curved parts. For example, at the knee joint, the shape of the joint is irregular and changes during movement. The traditional copper tape coil cannot be adaptively adjusted according to the shape and movement of the joint, resulting in the coil not being in close contact with the human body surface. Moreover, because the coil cannot fit the complex curved parts of the human body well, when receiving MRI signals at these parts, the distances between different positions and the coil are inconsistent, resulting in uneven signal reception. That is, the bend of the joint may be far away from the coil, and the received signal strength will be weaker, while the received signal strength may be stronger at other parts that fit the coil better, which affects the quality and accuracy of the imaging.

[0036] The solution of the present application adopts a wireless connection method to eliminate the direct electrical connection with the MRI system. This not only reduces the inconvenience and possible interference caused by the connection, but also simplifies the integration process of the coil, which may reduce costs. On the one hand, without the constraints of cables, it can be placed more freely in the part that needs to be imaged, whether it is a curved part of the human body or a hard-to-reach area, it can be operated more conveniently. For example, when imaging the joint part, the wireless coil can flexibly adjust the position as the joint moves and changes in shape, improving the convenience and accuracy of imaging. On the other hand, the electrical connection of the wired coil may introduce various interferences. For example, the cable may be affected by the surrounding electromagnetic field and generate induced currents. These induced currents will interfere with the normal reception and detection of the MRI signal by the coil, thereby generating artifacts on the image. The wireless coil transmits the signal through wireless communication, avoiding this interference caused by the electrical connection. During the imaging process, if the connecting cable of the wired coil moves, for example, the patient's inadvertent movement causes the cable to shake, the movement of the cable will change the electromagnetic environment of the coil, thereby affecting the reception and detection of the signal and causing artifacts on the image. Wireless coils have no cables, so there will be no problem of artifacts caused by cable movement. They can provide a more stable imaging environment and further improve imaging quality.

[0037] More importantly, by using high-impedance materials and designs, the mutual induction between adjacent elements is reduced. High impedance means greater resistance to current, limiting the flow of current between adjacent elements, thereby reducing signal loss and distortion. This is especially important for multi-channel MRI systems, which can improve the accuracy and efficiency of signal reception. Since the high-impedance design reduces the mutual induction between adjacent elements, the requirements for precise electromagnetic balance are relatively reduced. This makes the design and debugging process of the coil simpler and improves the versatility and ease of use of the coil. The adjacent elements here include the induction effects generated between adjacent coils, the induction effects generated by the transmitting coil and the pickup coil, and even the induction effects caused by other electrical harnesses, which can greatly improve the accuracy of imaging. On the other hand, it also reduces the requirements for equipment arrangement, algorithm design, and other aspects during imaging.

[0038] in, Figure 5 Comparison of signal-to-noise ratio when using BC body coil to receive signals, knee coil to receive signals, and passive high impedance gain coil. (a) (c) Relative placement. (b) (d) The signal is significantly improved when using passive high impedance gain coil and other coils in different situations. Comparison of signal-to-noise ratio size at the position shown in the right figure.

[0039] This application excels in signal enhancement effects in ankle and knee imaging, demonstrating its potential in improving imaging quality. The multi-channel configuration of the passive high-impedance gain coil supports more advanced imaging techniques, such as parallel imaging, further improving imaging speed and quality. During the design process, special attention was paid to the versatility and compatibility of the magnetic resonance passive high-impedance imaging gain system to ensure that it can be easily integrated into different MRI devices, while ensuring its safety and biocompatibility to meet the requirements of clinical use.

[0040] The magnetic resonance passive high-impedance imaging gain system disclosed by the present invention has the advantages that, due to the high impedance characteristics of the passive high-impedance gain coil itself, there are no special requirements for bending and relative placement distance during use, and the passive high-impedance gain coil itself is flexible. In the process of using the passive high-impedance gain coil array, not only does it not need to be specially designed for the relative placement position of the passive high-impedance gain coil, but it can also be bent at a large angle during use. Under such conditions, the present invention can still perform magnetic resonance signal enhancement in a relatively stable state.

[0041] In the above technology, impedance refers to the resistance to current flow. It is a complex number consisting of two parts: resistance and reactance. It is usually represented by the symbol Z and the unit is ohm (Ω).

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

[0043] Reactance: Inductive reactance (inductive reactance): When current passes through a coil, the electromagnetic induction phenomenon will generate a self-induced electromotive force, which will hinder the change of current. This hindering effect is called inductive reactance. The size of the inductive reactance is related to the inductance of the coil (L) and the frequency of the current (f), and its calculation formula is XL = 2πfL. In the above-mentioned wearable wireless high-impedance array technology, the inductance design of the coil will affect its inductive reactance, and then affect the overall impedance.

[0044] Capacitive reactance (capacitive reactance): In a circuit containing a capacitor, the capacitor also has an obstructive effect on the AC current, which is called capacitive reactance. The size of the capacitive reactance is related to the capacitance of the capacitor (C) and the frequency of the current (f), and the calculation formula is 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 8The present invention provides a flowchart of an imaging method for a magnetic resonance passive high impedance imaging gain system, wherein the imaging method comprises the following steps:

[0046] Step S1, determining the target part to be imaged, first covering the target part to be imaged with a passive high impedance gain coil, and then selecting a receiving (transmitting and picking up integrated) coil used with the target part to be imaged;

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

[0048] Step S3, sending the bed into the main magnet to perform a scanning process;

[0049] Step S4, end the inspection, remove the receiving (transmitting and picking up integrated) coil and the passive wireless high-resistance coil in turn, put them back into the locker, and the scanning is completed.

[0050] In general, when the magnetic resonance passive high-impedance gain system 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 stimulated to emit an electromagnetic signal, which is amplified when passing 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, Figure 1 As shown in part b, the detuning circuit is a bidirectional diode.

[0052] The detuning circuit is a bidirectional diode unit composed of two diodes connected in opposite directions and in parallel. Compared with other detuning circuits, the bidirectional diode unit has a simple structure, low cost, and reliable performance and structure. In other embodiments, the detuning circuit can also be a detuning circuit such as introducing a new detuning circuit, so as to achieve a detuning effect similar to that of 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, two bidirectional diode units are connected in series and then connected in parallel with a single-channel high-impedance coil and a resonant circuit. The setting of two sets of bidirectional diode units can make the passive high-impedance gain coil more robust. When one of the bidirectional diode units 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, and through the selection of capacitors and inductors, it can achieve a high resistance state at the excitation frequency, and the resonant frequency can be selected to meet the requirements for enhancing the electromagnetic signal.

[0057] Among them, the LC parallel resonant circuit is formed by a capacitor and an inductor in parallel, and the LC resonant circuit is not limited to having only two electronic components, a capacitor and an inductor. In other embodiments, other electronic components are added without changing the main functions achieved by the LC parallel resonant circuit, which should still be considered to belong to the LC parallel resonant circuit mentioned in this application.

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

[0059] Among them, the magnetic resonance passive high-impedance imaging gain system has at least two passive high-impedance gain coils, so that the magnetic resonance high-impedance coil array can enhance the detection point at multiple positions, and does not require inductive coupling during dynamic imaging, and does not cause image artifacts when the patient moves. The present invention seeks to maintain optimal performance in dynamic body movements, reduce motion artifacts, and improve imaging quality. By utilizing wireless technology and high-impedance design, the transmission and reception efficiency of signals is improved, thereby improving the overall performance of the MRI system. At the same time, the manufacturing and integration costs of the coil are reduced through innovative design, the integration process with the MRI system is simplified, and the economy and accessibility are improved. Specifically, a magnetic resonance high-impedance coil array disclosed in the present application has no requirements for placement position and bending angle, and can be used in conjunction with different types of commercial receiving coils, such as knee coils or head coils, thereby improving the signal-to-noise ratio, and no other images will appear for the imaged image.

[0060] Please refer to Figure 6 , Figure 7 and Fig. 9 ,in, Figure 6 This is a comparison diagram of a magnetic resonance high impedance coil array using a four-channel passive high impedance gain coil and a knee coil in combination at the ankle position and using only the knee coil for imaging, (a) relative placement, (b)(d) images of imaging using only the knee coil, (c)(e) images of the imaging effect of the knee coil combined with the passive high impedance gain coil array;

[0061] Figure 7This is a comparison diagram of a magnetic resonance high impedance coil array at the knee position using a 4-channel passive high impedance gain coil and a knee coil in combination with imaging using only the knee coil, (a) relative placement, (b)(d) images of imaging using only the knee coil, (c)(e) imaging effects of the knee coil combined with the passive high impedance gain coil array;

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

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

[0064] In some specific embodiments, any two adjacent passive high-impedance gain coils may be placed overlappingly or not overlappingly, that is, the present solution does not have high requirements on the placement of two adjacent passive high-impedance gain coils, and the spacing may be set relatively arbitrarily. Even if overlap occurs, the impact on imaging is very slight.

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

[0066] In some embodiments, the single-channel high-impedance coil has a deformability to fit the target part to be imaged and deform synchronously with the dynamics of the target part to be imaged.

[0067] It should be noted that the single-channel high-impedance coil has the ability to deform, so that the passive high-impedance gain coil can maintain a certain shape without the need for an external fixed structure to fix it. At the same time, it can also bend and deform with the external movement changes, so as to always maintain the imaging effect of the target. The ability to deform can enable the coil to better adapt to the dynamic changes of human body parts, and can achieve more uniform signal reception and improve imaging 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 the single-channel high-impedance coil is not less than 300 ohms, which is the high impedance mentioned in this application. The single-channel high-impedance coil specifically refers to an inductor coil in which current can only flow along a single path and presents a higher impedance to AC signals.

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

[0071] A coaxial cable is a cable used to transmit electrical signals, and its structure is similar to a concentric cylinder. The typical construction of a coaxial cable includes four main parts: Center conductor: It is composed of a metal wire, usually copper or aluminum, and is responsible for transmitting signals. The signal current flows in the center conductor. Insulation layer: The insulating material located outside the center conductor, usually polyethylene (PE) or polytetrafluoroethylene (PTFE) and other materials, used to isolate the center conductor and the outer conductor to prevent signal leakage or interference. Outer conductor: The metal conductor surrounded by the insulation layer, usually an aluminum foil layer or a copper mesh, plays a shielding role during signal transmission and reduces the impact of external interference on the signal. Outer sheath: The outer protective layer located outside the outer conductor, usually composed of materials such as polyvinyl chloride (PVC) or polyvinyl chloride (PE), has waterproof, insulating and protective functions.

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

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

[0074] Specifically, the covering unit, such as a film that meets the requirements, 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 to facilitate the placement and operation of the operator and further protect the passive high-impedance gain coil.

[0075] In some embodiments, the resonant circuit and the detuning circuit are both disposed at the same position of the single-channel high-impedance coil, thereby facilitating replacement and repair of the resonant circuit and the detuning circuit when they are damaged.

[0076] In the description of this specification, if the terms "embodiment one", "this embodiment", "in an embodiment" and the like appear, it means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in the invention or at least one embodiment or example of the invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example; moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in an appropriate manner.

[0077] In the description of this specification, the terms "connect", "install", "fix", "set", "have", etc. are all understood in a broad sense. 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 it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0078] In the description of this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0079] The above description of the embodiments is to facilitate ordinary technicians in the technical field to understand and apply the technology of this case. People familiar with the technology in this field can obviously easily make various modifications to these examples and apply the general principles described here to other embodiments without creative work. Therefore, this case is not limited to the above embodiments. Modifications to the following situations should all be within the scope of protection of this case: ① A new technical solution implemented based on the technical solution of the present invention and combined with existing common knowledge, the technical effect produced by the new technical solution does not exceed the technical effect of the present invention; ② The equivalent replacement of some features of the technical solution of the present invention by using known technology, the technical effect produced is the same as the technical effect of the present invention; ③ The technical solution of the present invention can be expanded, and the substantive content of the expanded technical solution does not exceed the technical solution of the present invention; ④ The equivalent transformation made by using the contents of the description and drawings of the present invention is directly or indirectly applied to other related technical fields.

Claims

1. A magnetic resonance passive high impedance imaging gain system, comprising a transmitting coil for transmitting magnetic resonance signals to a target part to be imaged and a pickup coil for receiving electromagnetic signals, characterized in that: A passive high impedance gain coil is provided at the target part to be imaged; The passive high-impedance gain coil includes a single-channel high-impedance coil, and the single-channel high-impedance coil 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. A magnetic resonance passive high impedance imaging gain system according to claim 1, characterized in that: The detuning circuit is a bidirectional diode unit.

3. A magnetic resonance passive high impedance imaging gain system according to claim 2, characterized in that: 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.

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. The magnetic resonance passive high impedance imaging gain system according to claim 1, characterized in that: At least two passive high-impedance gain coils are provided, and the plurality of passive high-impedance gain coils surround the target part to be imaged in a manner of covering a 360° range.

6. The magnetic resonance passive high impedance imaging gain system according to claim 5, characterized in that: Any two adjacent passive high impedance gain coils may be placed overlappingly or non-overlappingly.

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

8. The magnetic resonance passive high impedance imaging gain system according to claim 1, characterized in that: The single-channel high-impedance coil has a deformation capability to fit the target part to be imaged and deform synchronously with the dynamic state of the target part to be imaged.

9. A magnetic resonance passive high impedance imaging gain system 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 resistance coil is a coaxial cable.

Images