Radio frequency magnetic field enhancing device for magnetic resonance imaging and manufacturing method

Abstract

The invention provides a radio frequency magnetic field enhancing device for magnetic resonance imaging and a manufacturing method. The corresponding radio frequency magnetic field enhancing device comprises a substrate, at least one metamaterial layer arranged on the substrate, at least one control ring and at least one capacitance adjusting assembly, the metamaterial layer comprises at least one array unit, the array unit is formed by a strip-shaped non-magnetic material, and the array unit is in a spiral line shape; when the number of the array units is multiple, the multiple array units are arranged on the same plane in a mutual rotating and nesting mode; the control ring surrounds the non-magnetic materials on the outermost sides of the array units in the same metamaterial layer and is provided with at least one opening, and the capacitance adjusting assemblies are connected between the openings. The technical problem that the signal-to-noise ratio enhancement capability of magnetic resonance imaging is insufficient is solved, and nonlinear control over the radio frequency magnetic field in the receiving stage of magnetic resonance imaging and the radio frequency magnetic field in the transmitting stage of magnetic resonance imaging without typical circuit feature structures is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear magnetic resonance imaging, in particular to a radio frequency magnetic field enhancement device for magnetic resonance imaging and a manufacturing method. BACKGROUND

[0002] MRI (Magnetic Resonance Imaging) is a non-invasive detection method, and is an important basic diagnostic technique in the fields of medicine, biology and neuroscience. The signal strength transmitted by the existing MRI equipment mainly depends on the strength of the static magnetic field B0. Using a high magnetic field or even a super-high magnetic field system can improve the signal-to-noise ratio, resolution and shorten the scanning time of the image. However, the increase of the static magnetic field strength will bring the following three problems:

[0003] 1) The RF (Radio Frequency) field non-uniformity increases, and the tuning difficulty increases;

[0004] 2) The heat generated by the human body increases, which brings safety hazards, and the patient is also prone to dizziness, vomiting and other adverse reactions;

[0005] 3) The purchase cost increases substantially, which is a burden for most small-scale hospitals. Therefore, how to use the smallest static magnetic field strength while obtaining high imaging quality has become a crucial problem in MRI technology.

[0006] To solve the above problems, researchers have proposed a variety of solutions. The first is the RF coil optimization method, which greatly promotes the improvement of the detector resolution and scanning speed in MRI. Studies have shown that using parallel imaging can reduce the scanning time, and using multi-channel coils can achieve better imaging quality and larger detection area. However, this scheme has been relatively mature so far, and considering that optimizing the coil requires redesigning the MRI system, it brings many inconveniences for practical application. The second is to use special contrast agents to enhance the local magnetic field, such as rare earth magnetic atoms or magnetic nanoparticles. Since the contrast agent needs to be taken orally or injected into the human tissue or organ, there is a potential side effect or even a risk to life, so it is not the most ideal solution.

[0007] Firstly, the above-mentioned various methods use a larger lumped capacitor, which leads to a decrease in the equivalent inductance, a decrease in the ability of the device to store magnetic energy, and a decrease in the image signal-to-noise ratio enhancement factor of the structure.

[0008] On the other hand, existing radio frequency magnetic field enhancement devices mainly rely on lumped capacitors and pin diodes to control the radio frequency magnetic field in the receiving and transmitting stages of magnetic resonance imaging (MRI), making it difficult to achieve nonlinear control of the radio frequency magnetic field in the receiving and transmitting stages of MRI without typical circuit feature structures. Summary of the Invention

[0009] This invention provides a submagnetic surface plasmonic metamaterial with a special configuration, which effectively solves the technical problem of nonlinear control of existing radio frequency magnetic field enhancement devices that lack typical circuit feature structures.

[0010] In order to solve at least one of the above-mentioned problems in the prior art, embodiments of this application provide a radio frequency magnetic field enhancement device for magnetic resonance imaging and a method for manufacturing the same.

[0011] According to a first aspect of the embodiments of this application, this application provides a radio frequency magnetic field enhancement device for magnetic resonance imaging, comprising:

[0012] A substrate, at least one metamaterial layer disposed on the substrate, at least one control ring, and at least one capacitance adjustment component;

[0013] The metamaterial layer includes at least one array unit, which is formed of strip-shaped non-magnetic material and is helical in shape.

[0014] When there are multiple array units, the multiple array units are arranged on the same plane by mutual rotation and nesting; and

[0015] The control ring surrounds the outermost non-magnetic material of multiple array units within the same metamaterial layer and has at least one opening, with the capacitance adjustment component connected between each opening; the capacitance of the capacitance adjustment component is adjustable to perform nonlinear control of the radio frequency magnetic field during the receiving phase and the radio frequency magnetic field during the transmitting phase of magnetic resonance imaging.

[0016] When there are multiple metamaterial layers, the multiple metamaterial layers are stacked on the substrate, and the metamaterial layers and the control ring have a one-to-one correspondence.

[0017] In some embodiments of this application, during the receiving phase of the magnetic resonance imaging, the capacitance of the capacitance adjustment component is increased so that the resonant frequency of the radio frequency magnetic field enhancement device is the same as the Larmor frequency of the magnetic resonance imaging.

[0018] In some embodiments of this application, during the transmission phase of the magnetic resonance imaging, the capacitance of the capacitance adjustment component is reduced so that the resonant frequency of the radio frequency magnetic field enhancement device is different from the Larmor frequency of the magnetic resonance imaging.

[0019] In some embodiments of this application, the distance between adjacent non-magnetic materials in the metamaterial layer is adjustable to adjust the enhancement factor of the radio frequency magnetic field of the radio frequency magnetic field enhancement device.

[0020] In some embodiments of this application, the number of turns formed by the non-magnetic material in the metamaterial layer is adjustable to adjust the enhancement factor of the radio frequency magnetic field of the radio frequency magnetic field enhancement device.

[0021] In some embodiments of this application, the linewidth of the non-magnetic material is adjustable to adjust the enhancement factor of the radio frequency magnetic field of the radio frequency magnetic field enhancement device.

[0022] In some embodiments of this application, the array unit is an axisymmetric structure.

[0023] In some embodiments of this application, the spiral centers of the plurality of array units coincide with each other.

[0024] In some embodiments of this application, the angles formed by the adjacent line segments connecting the outer endpoints of each of the at least two array units to the spiral center are equal; the angles are formed by the adjacent line segments and the spiral center.

[0025] In some embodiments of this application, the spiral shape includes: a circular spiral, a rectangular spiral, and an involute.

[0026] According to a second aspect of the embodiments of this application, this application provides a method for manufacturing a radio frequency magnetic field enhancement device for magnetic resonance imaging as described in the first aspect, the method comprising:

[0027] The resonant frequency of the radio frequency magnetic field is determined based on the pre-set enhancement factor of the radio frequency magnetic field of the radio frequency magnetic field enhancement device.

[0028] The equivalent capacitance and equivalent inductance of the radio frequency magnetic field enhancement device are determined based on the resonant frequency.

[0029] The radio frequency magnetic field enhancement device is manufactured based on the equivalent capacitance and equivalent inductance.

[0030] In some embodiments of this application, the radio frequency magnetic field enhancement device is manufactured based on the equivalent capacitance and equivalent inductance, including:

[0031] The configuration parameters of the radio frequency magnetic field enhancement device are determined based on the equivalent capacitance and the equivalent inductance.

[0032] The radio frequency magnetic field enhancement device is manufactured according to the configuration parameters.

[0033] In some embodiments of this application, the configuration parameters include: the distance between adjacent non-magnetic materials of the radio frequency magnetic field enhancement device, the number of turns formed by the non-magnetic material, the number of openings in the control ring, and the linewidth of the non-magnetic material.

[0034] As described above, embodiments of the present invention provide a radio frequency magnetic field enhancement device and manufacturing method for magnetic resonance imaging. The corresponding radio frequency magnetic field enhancement device for magnetic resonance imaging includes: a substrate, at least one metamaterial layer disposed on the substrate, at least one control ring, and at least one capacitor adjustment component. The metamaterial layer includes at least one array unit, which is formed of strip-shaped non-magnetic material and is helical. When there are multiple array units, the multiple array units are disposed on the same plane by mutual rotation and nesting. The control ring surrounds the outermost non-magnetic material of the multiple array units within the same metamaterial layer and is provided with at least one opening, with the capacitor adjustment component connected between each opening. The capacitance of the capacitor adjustment component is adjustable to perform nonlinear control of the radio frequency magnetic field during the receiving phase and the transmitting phase of magnetic resonance imaging. When there are multiple metamaterial layers, the multiple metamaterial layers are stacked on the substrate, and the metamaterial layers and the control ring are in a one-to-one correspondence.

[0035] A method for manufacturing a radio frequency magnetic field enhancement device for magnetic resonance imaging includes: determining the resonant frequency of the radio frequency magnetic field based on a pre-set enhancement factor of the radio frequency magnetic field of the enhancement device; determining the equivalent capacitance and equivalent inductance of the radio frequency magnetic field enhancement device based on the resonant frequency; and manufacturing the radio frequency magnetic field enhancement device based on the equivalent capacitance and equivalent inductance.

[0036] The radio frequency magnetic field enhancement device for magnetic resonance imaging proposed in this invention solves the technical problem of insufficient signal-to-noise ratio enhancement capability in magnetic resonance imaging, and realizes nonlinear control of the radio frequency magnetic field in the receiving stage and the transmitting stage of magnetic resonance imaging without typical circuit feature structures. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0038] Figure 1 This is a schematic diagram of a radio frequency magnetic field enhancement device for magnetic resonance imaging according to an embodiment of this application.

[0039] Figure 2 This is another schematic diagram of a radio frequency magnetic field enhancement device for magnetic resonance imaging according to an embodiment of this application.

[0040] Figure 3 This is a schematic diagram of a method for manufacturing a radio frequency magnetic field enhancement device for magnetic resonance imaging according to an embodiment of this application.

[0041] Figure 4 This is a flowchart illustrating step 300 of a method for manufacturing a radio frequency magnetic field enhancement device for magnetic resonance imaging according to an embodiment of this application.

[0042] Figure 5 This is a schematic diagram illustrating an application scenario of a radio frequency magnetic field enhancement device for magnetic resonance imaging according to an embodiment of this application.

[0043] Figure 6 This is a schematic diagram illustrating the principle of the radio frequency magnetic field enhancement device for magnetic resonance imaging before its application, according to an embodiment of this application.

[0044] Figure 7 This is a schematic diagram illustrating the principle of the radio frequency magnetic field enhancement device for magnetic resonance imaging according to an embodiment of this application.

[0045] Figure 8 This is a schematic diagram of the structure of an electronic device in an embodiment of the present invention.

[0046] Figure label:

[0047] 1: Base;

[0048] 2: Metamaterial layer;

[0049] 3: Control loop;

[0050] 4: Capacitor adjustment component;

[0051] 5: Opening;

[0052] 6, 7: Coils;

[0053] 8: Radio frequency magnetic field enhancement devices;

[0054] 9: Mobile hospital beds;

[0055] 10: Radio frequency transmitting coil (body coil);

[0056] 11: Gradient coil;

[0057] 12: Main magnet coil. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0060] It should be noted that the terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or apparatuses. Without conflict, the embodiments and features in the embodiments of this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0061] In order to solve at least one of the above-mentioned problems in the prior art, in a first aspect, embodiments of this application provide a radio frequency magnetic field enhancement device for magnetic resonance imaging. Figure 1 This is a schematic diagram of a radio frequency magnetic field enhancement device for magnetic resonance imaging according to an embodiment of this application. Figure 1 As shown, the radio frequency magnetic field enhancement device for magnetic resonance imaging includes:

[0062] The substrate 1, at least one metamaterial layer 2 disposed on the substrate, at least one control ring 3, and at least one capacitor adjustment component 4;

[0063] The metamaterial layer includes at least one array unit ( Figure 1 The array has four array units, which are formed of strip-shaped non-magnetic material and are spiral-shaped.

[0064] When there are multiple array units, the multiple array units are arranged on the same plane by mutual rotation and nesting; and

[0065] The control ring 3 (metal ring) surrounds the outermost non-magnetic material of multiple array units within the same metamaterial layer 2, and is provided with at least one opening 5. The capacitor adjustment component 4 is connected between each opening 5 (between two breaks). The capacitor adjustment component 4 is adjustable to perform nonlinear control of the radio frequency magnetic field during the receiving phase and the radio frequency magnetic field during the transmitting phase of magnetic resonance imaging. A capacitor adjustment component is connected between each opening 5.

[0066] When there are multiple metamaterial layers 2, the multiple metamaterial layers 2 are stacked on the substrate 1, that is, the multiple metamaterial layers 2 are stacked together along a direction perpendicular to the aforementioned plane. Furthermore, there is a one-to-one correspondence between the metamaterial layers and the control rings, that is, one metamaterial layer corresponds to one control ring.

[0067] It is understandable that, firstly, the radio frequency magnetic field enhancement device with the above configuration provided in this application solves the technical problem of insufficient signal-to-noise ratio enhancement capability of magnetic resonance imaging, and realizes nonlinear control of the radio frequency magnetic field in the receiving stage and the transmitting stage of magnetic resonance imaging without typical circuit feature structure.

[0068] Secondly, the radio frequency magnetic field enhancement device with the above-mentioned configuration provided in this application overcomes the technical problem in the prior art where the radio frequency magnetic field enhancement device has a large lumped capacitance, which leads to a decrease in equivalent inductance, a decrease in the device's ability to store magnetic energy, and consequently a decrease in the image signal-to-noise ratio enhancement factor of the structure. The radio frequency magnetic field enhancement device is made of metamaterials and has a special configuration, which can reduce capacitance and increase the inductance of the structure, thereby improving the magnetic field enhancement performance of the structure.

[0069] Finally, the radio frequency magnetic field enhancement device with the above configuration provided in this application does not contain lumped capacitance, but rather small structural capacitance is formed between units. Therefore, the radio frequency magnetic field enhancer with this configuration has a large equivalent inductance and a strong ability to store magnetic energy and enhance the magnetic field, so the image signal-to-noise ratio enhancement factor of the structure will not decrease.

[0070] In some embodiments of this application, during the receiving phase of the magnetic resonance imaging, the capacitance of the capacitance adjustment component is increased so that the resonant frequency of the radio frequency magnetic field enhancement device is the same as the Larmor frequency of the magnetic resonance imaging.

[0071] In some embodiments of this application, during the transmission phase of the magnetic resonance imaging, the capacitance of the capacitance adjustment component is reduced so that the resonant frequency of the radio frequency magnetic field enhancement device is different from the Larmor frequency of the magnetic resonance imaging.

[0072] In some embodiments of this application, the capacitance adjustment component is a varactor diode capacitor. It is understood that the capacitance value of a varactor diode decreases as the voltage across it increases. Therefore, in the receiving phase of magnetic resonance imaging (MRI), the voltage across the varactor diode is low, the capacitance value is large, and the operating frequency is low, which coincides with the Larmor frequency of MRI, thus resonating and enhancing the signal field and improving the image signal-to-noise ratio. However, in the transmitting phase of MRI, the voltage across the varactor diode is high, the capacitance value is small, and the operating frequency is higher, deviating from the Larmor frequency and not affecting the RF transmitting field.

[0073] A varactor diode is a special type of diode whose capacitance can be adjusted by applying a reverse bias voltage across its terminals.

[0074] The working principle of a varactor diode is based on the capacitance effect of a PN junction. When a reverse bias voltage is applied to a varactor diode, the depletion layer width of the PN junction region increases, resulting in a decrease in the diode's capacitance. Conversely, reducing the reverse bias voltage decreases the depletion layer width, thereby increasing the capacitance. The capacitance value of a varactor diode typically ranges from a few picofarads (pF) to several hundred picofarads (pF), depending on the diode model and design. The relationship between capacitance and bias voltage is non-linear and can be described by specific formulas or graphs.

[0075] Larmor frequency refers to the spin precession frequency of a spin system (such as an atomic nucleus or an electron) in an external magnetic field. Specifically, when a charged particle (such as an electron or an atomic nucleus) is in a constant external magnetic field, its spin state will rotate at the Larmor frequency.

[0076] In MRI, the Larmor frequency determines the frequency of the radiofrequency pulse, which is crucial for exciting the NMR signal. Only when the frequency of the radiofrequency pulse matches the Larmor frequency of a specific nucleus in the sample can an NMR signal be effectively excited. This matching is fundamental to NMR spectral analysis and MRI techniques because it provides a method for precisely controlling and measuring the behavior of atomic nuclei in a magnetic field. Different nucleus types (such as hydrogen and carbon nuclei) have different gyromagnetic ratios, and therefore their Larmor frequencies will differ even in the same magnetic field. The Larmor frequency depends on the strength of the external magnetic field and the gyromagnetic ratio of the nuclide. Different nuclides have different gyromagnetic ratios, and therefore their Larmor frequencies also differ.

[0077] In some embodiments of this application, the distance between adjacent non-magnetic materials in the metamaterial layer 2 is adjustable (e.g., Figure 1 The distance between coil 6 and coil 7 (which are made of non-magnetic materials) is adjusted to increase the enhancement factor of the radio frequency magnetic field of the radio frequency magnetic field enhancement device.

[0078] In some embodiments of this application, the number of turns formed by the non-magnetic material in the metamaterial layer 2 (e.g.) Figure 1The total number of turns of the intermediate coil 6, coil 7 and other coils is adjustable to adjust the enhancement factor of the radio frequency magnetic field of the radio frequency magnetic field enhancement device.

[0079] In some embodiments of this application, the linewidth of the non-magnetic material is adjustable (e.g., Figure 1 The widths of coil 6, coil 7, and other coils corresponding to the non-magnetic material in the device are adjusted to increase the enhancement factor of the radio frequency magnetic field of the radio frequency magnetic field enhancement device.

[0080] In some embodiments of this application, Figure 1 The spiral of the array unit shown is supported by metallic copper (or other non-magnetic material), with a line width of 2 mm, a total of 6 turns, a distance of 16 mm between adjacent turns, and a thickness (width) of 12 micrometers for the metallic copper.

[0081] In some embodiments of this application, when the structure is axially symmetric, the number of array units can be 2 to 10.

[0082] In some embodiments of this application, the array unit is generally an axisymmetric structure.

[0083] In some embodiments of this application, the helical centers of the plurality of array elements coincide with each other. See also Figure 1 It is a schematic diagram of a configuration with four array units, and the spiral centers of the four array units coincide at point A.

[0084] In some embodiments of this application, the angles formed by the adjacent line segments connecting the outer endpoints of each of the at least two array units to the spiral center are equal; the angles are formed by the adjacent line segments and the spiral center.

[0085] Figure 1 The configuration of the radio frequency magnetic field enhancement device shown has four array units. The four angles formed by connecting the outer endpoints B, C, D and E of the three array units to point A are equal, that is, each angle is 360° / 4 = 90°.

[0086] When the radio frequency magnetic field enhancement device has two array units, the two angles formed by connecting the outer endpoints of the two array units to point A are equal, that is, each angle is 360° / 2 = 180°.

[0087] When the radio frequency magnetic field enhancement device has three array units, the three angles formed by connecting the outer endpoints of the three array units to point A are equal, that is, each angle is 360° / 3 = 120°.

[0088] It should be noted that the varying number of rotation angles is primarily for achieving the desired target resonant frequency. Generally, as the number of these arrays increases, the equivalent inductance and equivalent capacitance also gradually increase, and the resonant frequency gradually decreases. While the resonant frequency decreases, the enhancement factor of the radio frequency magnetic field at that frequency also slowly increases.

[0089] In some embodiments of this application, the spiral shape includes: a circular spiral, a rectangular spiral, etc. Figure 2 This type of radio frequency magnetic field enhancement device and Figure 1 The difference between the circular spiral radio frequency magnetic field enhancement device and the involute is that the equivalent inductance and equivalent capacitance formed by the two will be different, the structural dimensions at the same resonant frequency will be different, and the distribution of the radio frequency magnetic field will be different.

[0090] As described above, embodiments of the present invention provide a radio frequency magnetic field enhancement device for magnetic resonance imaging, comprising: a substrate, at least one metamaterial layer disposed on the substrate, at least one control ring, and at least one capacitor adjustment component; the metamaterial layer includes at least one array unit, the array unit being formed of strip-shaped non-magnetic material, and the array unit being helical; when there are multiple array units, the multiple array units are disposed on the same plane by mutual rotation and nesting; and the control ring surrounds the outermost non-magnetic material of the multiple array units within the same metamaterial layer, and is provided with at least one opening, each opening being connected to the capacitor adjustment component; the capacitance of the capacitor adjustment component is adjustable to perform nonlinear control of the radio frequency magnetic field during the receiving phase and the radio frequency magnetic field during the transmitting phase of magnetic resonance imaging; when there are multiple metamaterial layers, the multiple metamaterial layers are stacked on the substrate, and the metamaterial layers and the control ring are in a one-to-one correspondence.

[0091] The radio frequency magnetic field enhancement device for magnetic resonance imaging proposed in this invention solves the technical problem of insufficient signal-to-noise ratio enhancement capability in magnetic resonance imaging, and realizes nonlinear control of the radio frequency magnetic field in the receiving stage and the transmitting stage of magnetic resonance imaging without typical circuit feature structures.

[0092] On the other hand, embodiments of the present invention also provide a method for manufacturing a radio frequency magnetic field enhancement device for magnetic resonance imaging.

[0093] The emergence of metamaterials offers a novel and more effective method for improving the quality and efficiency of MRI imaging. Metamaterials possess many unique properties not found in natural materials. By utilizing the interaction between electromagnetic waves and the metallic or dielectric components of metamaterials, as well as the coupling effect between these components, it is possible to control the propagation path of electromagnetic waves and the distribution of electromagnetic field strength. Its working principle involves using the electromagnetic resonance of its structural units to achieve anisotropic and gradient-distributed, even negative, electromagnetic parameters. Furthermore, by designing parameters such as the geometry, shape, and dielectric constant of the metamaterial, resonance enhancement at different frequencies can be achieved. Metamaterials have potential applications in the design and fabrication of devices and equipment that manipulate electromagnetic waves, and MRI is one important application area.

[0094] There are three main metrics for evaluating MRI image quality: resolution, signal-to-noise ratio (SNR), and contrast ratio. Higher image resolution allows for more detailed images to be displayed; a higher SNR results in a clearer image, and a high SNR can also support higher resolution or shorten scan time; contrast ratio is crucial for distinguishing normal tissue from diseased tissue. Metamaterials can improve the image SNR by altering the magnetic field distribution within the MRI system. Metamaterial-inspired magnetic surface plasmons can enhance the local field, thereby improving the image SNR.

[0095] See Figure 3 A method for manufacturing a radio frequency magnetic field enhancement device for magnetic resonance imaging, comprising:

[0096] Step 100: Determine the resonant frequency of the radio frequency magnetic field based on the pre-set enhancement factor of the radio frequency magnetic field of the radio frequency magnetic field enhancement device;

[0097] Specifically, first determine the model of the magnetic resonance system, and then determine the resonant frequency of the radio frequency magnetic field based on the required enhancement factor of the radio frequency magnetic field. See [link to relevant documentation]. Figure 7 The magnetic field strength of the original radio frequency magnetic field of the magnetic resonance system is B. After passing through the radio frequency magnetic field enhancement device, the magnetic field strength is enhanced to αB, that is, the enhancement factor is α.

[0098] Step 200: Determine the equivalent capacitance and equivalent inductance of the radio frequency magnetic field enhancement device based on the resonant frequency;

[0099] Step 300: Fabricate the radio frequency magnetic field enhancement device based on the equivalent capacitance and equivalent inductance.

[0100] In some embodiments of this application, see Figure 4 Step 300 includes:

[0101] Step 301: Determine the configuration parameters of the radio frequency magnetic field enhancement device based on the equivalent capacitance and the equivalent inductance;

[0102] Step 302: Fabricate the radio frequency magnetic field enhancement device according to the configuration parameters.

[0103] In some embodiments of this application, the configuration parameters include: the distance between adjacent non-magnetic materials of the radio frequency magnetic field enhancement device, the number of turns formed by the non-magnetic material, the number of openings in the control ring, and the linewidth of the non-magnetic material.

[0104] The parametric equations for the helix of the radio frequency magnetic field enhancement device are as follows:

[0105]

[0106] Where x and y are the abscissa and ordinate of the helix, θ is the polar angle, and A is the amplitude of the helix, which is numerically equal to the distance between adjacent non-magnetic materials of the RF magnetic field enhancement device (the distance between adjacent solenoids); the number of coils is related to θ. The equivalent capacitance and equivalent inductance of the metamaterial can be adjusted by the number of coils θ, the distance A between adjacent solenoids, and the width of the solenoids.

[0107] This invention also provides an application scenario for a radio frequency magnetic field enhancement device for magnetic resonance imaging, see [link to relevant documentation]. Figure 5 The radio frequency magnetic field enhancer 8 is positioned at the human body part where the radio frequency magnetic field needs to be enhanced (when used for magnetic resonance signal-to-noise ratio enhancement, simply attach the radio frequency magnetic field enhancer to the part to be tested (abdomen, head, etc.) and use a suitable receiving coil to receive it (including but not limited to spinal coil, head coil, and body coil, etc.)). Figure 4 In the diagram, 9 is a mobile hospital bed, which can move the human body to the optimal position according to the testing needs; 10 is a radio frequency transmitting coil (body coil); 11 is a gradient coil; and 12 is the main magnet coil.

[0108] Based on the above application scenarios of radio frequency magnetic field enhancement devices for magnetic resonance imaging, see [link to relevant documentation]. Figure 6 as well as Figure 7 This invention also provides a method for using a radio frequency magnetic field enhancement device for magnetic resonance imaging (MRI). The method is as follows: the capacitance of a varactor diode decreases as the voltage across it increases. Therefore, during the receiving phase of MRI, the varactor diode operates at a low voltage and high capacitance, with a low operating frequency, which coincides with the Larmor frequency of MRI, thus enhancing the resonant signal field. to This improves the image signal-to-noise ratio. During the emission phase of magnetic resonance imaging, the varactor diode has a high voltage across its terminals, a small capacitance, and an increased operating frequency, deviating from the Larmor frequency, but without affecting the radio frequency transmission field.

[0109] The structure following the RF magnetic field enhancement device array can be attached to substrates of different shapes, thus making it suitable for imaging in different scenarios. Furthermore, the RF magnetic field enhancement devices can be combined (e.g., two halves snapped together). (In this case, when RF magnetic field enhancement devices are stacked vertically together, the response to the RF magnetic field will be perpendicular to both directions, which is relatively low. When the aforementioned single RF magnetic field enhancement device is placed in parallel, it will only respond to the RF magnetic field in the direction perpendicular to the plane.)

[0110] As can be seen from the above description, the present invention provides a method for manufacturing a radio frequency magnetic field enhancement device for magnetic resonance imaging, comprising: determining the resonant frequency of the radio frequency magnetic field according to a pre-set enhancement factor of the radio frequency magnetic field of the radio frequency magnetic field enhancement device; determining the equivalent capacitance and equivalent inductance of the radio frequency magnetic field enhancement device according to the resonant frequency; and manufacturing the radio frequency magnetic field enhancement device according to the equivalent capacitance and equivalent inductance.

[0111] The radio frequency magnetic field enhancement device manufactured using the manufacturing method of the radio frequency magnetic field enhancement device for magnetic resonance imaging proposed in the embodiments of the present invention solves the technical problem of insufficient signal-to-noise ratio enhancement capability of magnetic resonance imaging, and realizes nonlinear control of the radio frequency magnetic field in the receiving stage and the transmitting stage of magnetic resonance imaging without typical circuit feature structure.

[0112] Furthermore, the aforementioned radio frequency magnetic field enhancement device has the advantages of having no lumped capacitance, only a small structural capacitance, and a large equivalent inductance, resulting in a strong ability to store magnetic energy and enhance the magnetic field. This overcomes the technical problem in existing radio frequency magnetic field enhancement devices where a large lumped capacitance leads to a decrease in equivalent inductance, a reduction in the device's ability to store magnetic energy, and consequently a decrease in the image signal-to-noise ratio enhancement factor.

[0113] The embodiments of this application also provide a specific implementation of an electronic device capable of implementing all the steps in the manufacturing method of the radio frequency magnetic field enhancement device for magnetic resonance imaging described in the above embodiments. See [link to relevant documentation]. Figure 8 The electronic devices specifically include the following:

[0114] Processor 1201, memory 1202, communications interface 1203, and bus 1204;

[0115] The processor 1201, memory 1202, and communication interface 1203 communicate with each other via bus 1204; the communication interface 1203 is used to realize information transmission between server-side devices and client-side devices and other related devices.

[0116] The processor 1201 is used to call the computer program in the memory 1202. When the processor executes the computer program, it implements all the steps in the manufacturing method of the radio frequency magnetic field enhancement device for magnetic resonance imaging in the above embodiment. For example, when the processor executes the computer program, it implements the following steps:

[0117] Step 100: Determine the resonant frequency of the radio frequency magnetic field based on the pre-set enhancement factor of the radio frequency magnetic field of the radio frequency magnetic field enhancement device;

[0118] Step 200: Determine the equivalent capacitance and equivalent inductance of the radio frequency magnetic field enhancement device based on the resonant frequency;

[0119] Step 300: Fabricate the radio frequency magnetic field enhancement device based on the equivalent capacitance and equivalent inductance.

[0120] Embodiments of this application also provide a computer-readable storage medium capable of implementing all steps of the manufacturing method for the radio frequency magnetic field enhancement device for magnetic resonance imaging described in the above embodiments. The computer-readable storage medium stores a computer program that, when executed by a processor, implements all steps of the manufacturing method for the radio frequency magnetic field enhancement device for magnetic resonance imaging described in the above embodiments. For example, when the processor executes the computer program, it implements the following steps:

[0121] Step 100: Determine the resonant frequency of the radio frequency magnetic field based on the pre-set enhancement factor of the radio frequency magnetic field of the radio frequency magnetic field enhancement device;

[0122] Step 200: Determine the equivalent capacitance and equivalent inductance of the radio frequency magnetic field enhancement device based on the resonant frequency;

[0123] Step 300: Fabricate the radio frequency magnetic field enhancement device based on the equivalent capacitance and equivalent inductance.

[0124] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, hardware + program embodiments are relatively simple in description because they are fundamentally similar to method embodiments; relevant parts can be referred to the descriptions in the method embodiments.

[0125] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0126] While this application provides method operation steps as shown in the embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-inventive labor. The order of steps listed in the embodiments is merely one possible execution order among many and does not represent the only execution order. In actual device or client product execution, the method can be executed sequentially as shown in the embodiments or drawings, or in parallel (e.g., in a parallel processor or multi-threaded processing environment).

[0127] For ease of description, the above devices are described in terms of function, divided into various modules. Of course, in implementing the embodiments of this specification, the functions of each module can be implemented in one or more software and / or hardware components, or a module that performs the same function can be implemented by a combination of multiple sub-modules or sub-units. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between devices or units, and may be electrical, mechanical, or other forms.

[0128] Those skilled in the art will also know that, besides implementing the controller using purely computer-readable program code, the same functions can be achieved by logically programming the method steps, making the controller function as logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers (PLCs), and embedded microcontrollers. Therefore, such a controller can be considered a hardware component, and the devices within it used to implement various functions can also be considered structures within that hardware component. Alternatively, the devices used to implement various functions can be considered as both software modules implementing the method and structures within a hardware component.

[0129] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0130] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0131] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, system embodiments are basically similar to method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. In the description of this specification, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments in this specification. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0132] The above description is merely an embodiment of the present specification and is not intended to limit the embodiments of the present specification. For those skilled in the art, various modifications and variations can be made to the embodiments of the present specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the embodiments of the present specification should be included within the scope of the claims of the embodiments of the present specification.

Claims

1. A radio frequency magnetic field enhancement device for magnetic resonance imaging, characterized in that, The application relates to a radio frequency magnetic field enhancement device, comprising: a substrate, at least one metamaterial layer arranged on the substrate, at least one control ring, and at least one capacitance adjusting component; the metamaterial layer comprises at least one array unit formed by strip-shaped non-magnetic material, and the array unit is in the shape of a spiral line; when the number of array units is multiple, the multiple array units are arranged on the same plane in a mutually rotating and nested manner; and the control ring surrounds the outermost non-magnetic material of the multiple array units in the same metamaterial layer, and is provided with at least one opening, and each opening is connected with the capacitance adjusting component; the capacitance of the capacitance adjusting component is adjustable to nonlinearly control the radio frequency magnetic field in the receiving stage of magnetic resonance imaging and the radio frequency magnetic field in the transmitting stage of magnetic resonance imaging; when the metamaterial layer is multiple, the multiple metamaterial layers are stacked on the substrate, and the metamaterial layer and the control ring are in one-to-one correspondence.

2. The radio frequency magnetic field enhancement device of claim 1, wherein, In the receiving stage of magnetic resonance imaging, the capacitance of the capacitance adjusting component is increased to make the resonant frequency of the radio frequency magnetic field enhancement device the same as the Larmor frequency of the magnetic resonance imaging.

3. The radio frequency magnetic field enhancement device of claim 1, wherein, In the transmitting stage of magnetic resonance imaging, the capacitance of the capacitance adjusting component is reduced to make the resonant frequency of the radio frequency magnetic field enhancement device different from the Larmor frequency of the magnetic resonance imaging.

4. The radio frequency magnetic field enhancement device of claim 1, wherein, The distance between the adjacent non-magnetic materials in the metamaterial layer is adjustable to adjust the enhancement multiple of the radio frequency magnetic field of the radio frequency magnetic field enhancement device.

5. The radio frequency magnetic field enhancement device of claim 1, wherein, The number of turns formed by the non-magnetic material in the metamaterial layer is adjustable to adjust the enhancement multiple of the radio frequency magnetic field of the radio frequency magnetic field enhancement device.

6. The radio frequency magnetic field enhancement device of claim 1, wherein, The line width of the non-magnetic material is adjustable to adjust the enhancement multiple of the radio frequency magnetic field of the radio frequency magnetic field enhancement device.

7. The radio frequency magnetic field enhancement device of claim 1, wherein, The spiral centers of the multiple array units are coincident with each other.

8. The radio frequency magnetic field enhancement device of claim 7, wherein, The angles formed by the adjacent line segments connected with the spiral center of each of the at least two array units are equal; the angles are formed by the adjacent line segments and the spiral center.

9. A method of manufacturing a radio frequency magnetic field enhancement device for magnetic resonance imaging as claimed in any one of claims 1 to 8, characterized in that, The method comprises: determining the resonant frequency of the radio frequency magnetic field according to the preset enhancement multiple of the radio frequency magnetic field of the radio frequency magnetic field enhancement device; determining the equivalent capacitance and the equivalent inductance of the radio frequency magnetic field enhancement device according to the resonant frequency; manufacturing the radio frequency magnetic field enhancement device according to the equivalent capacitance and the equivalent inductance.

10. The manufacturing method according to claim 9, wherein Manufacturing the radio frequency magnetic field enhancement device according to the equivalent capacitance and the equivalent inductance comprises: determining the configuration parameters of the radio frequency magnetic field enhancement device according to the equivalent capacitance and the equivalent inductance; manufacturing the radio frequency magnetic field enhancement device according to the configuration parameters; the configuration parameters comprise the distance between the adjacent non-magnetic materials of the radio frequency magnetic field enhancement device, the number of turns formed by the non-magnetic material, the number of openings of the control ring, and the line width of the non-magnetic material.

Images