A radio frequency coil, a magnetic resonance probe and a single-sided magnetic resonance imaging system

Abstract

The present application belongs to the technical field of magnetic resonance imaging, and aims to provide a radio frequency coil, a magnetic resonance probe and a single-sided magnetic resonance imaging system. The present application discloses a radio frequency coil for single-sided magnetic resonance imaging, which comprises a radio frequency coil body and a radio frequency coil support, the radio frequency coil body is arranged on the radio frequency coil support, the shape of the radio frequency coil body is a polygon, and any internal angle of the polygon is not 90 degrees. A magnetic resonance probe comprises the radio frequency coil. A single-sided magnetic resonance imaging system comprises the magnetic resonance probe. The present application can improve the accuracy of single-sided magnetic resonance detection.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of magnetic resonance imaging, and particularly relates to a radio frequency coil, a magnetic resonance probe and a single-sided magnetic resonance imaging system. BACKGROUND

[0002] The magnetic resonance imaging technology has advantages of non-invasion, non-radiation and multi-parameter measurement, and from the perspective of safety, accuracy and stability, the magnetic resonance imaging detection technology is the optimal non-invasive detection technology for fatty liver at present. In order to reduce the volume of the magnetic resonance imaging equipment and realize the mobile function of the magnetic resonance imaging equipment, so that the magnetic resonance imaging equipment can complete the bedside detection, a single-sided magnetic resonance imaging system based on a single-sided magnet (a non-uniform field magnet) can be selected to realize the magnetic resonance imaging in the process of the nuclear magnetic resonance examination for fatty liver.

[0003] However, in the process of using the prior art, the inventors found that at least the following problems exist in the prior art:

[0004] The single-sided magnet is often accompanied by an undesirable situation of a single-sided magnetic resonance imaging system excitation region, resulting in low accuracy of liver detection using the single-sided magnetic resonance imaging system. Specifically, in the process of liver detection using the single-sided magnetic resonance imaging system, a radio frequency coil is used to generate a radio frequency magnetic field (referred to as "B1 field") in the target region (human liver), which is used to excite the atomic nucleus in the target region, and the closer the direction of the B1 field to 90 degrees with the direction of the B0 field (i.e. the main magnetic field), the greater the excitation strength; however, since the B0 field generated by the single-sided magnet for liver detection has a small uniform region, the equipotential line distribution range of the same magnetic field strength is large, so that the B1 field cannot be selected to excite the target liver region, and a large amount of tissues outside the liver will also be excited, resulting in a decline in the quality of magnetic resonance imaging and inaccurate liver detection results. SUMMARY

[0005] The present application aims to at least partially solve the above technical problems, and provides a radio frequency coil, a magnetic resonance probe and a single-sided magnetic resonance imaging system.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a radio frequency coil for single-sided magnetic resonance imaging, the radio frequency coil comprising a radio frequency coil body and a radio frequency coil support, the radio frequency coil body being arranged on the radio frequency coil support, the shape of the radio frequency coil body being a polygon, and any internal angle of the polygon being not 90 degrees.

[0008] In one possible design, the shape of the radio frequency coil body is a rhombus.

[0009] In a possible design, the radio frequency coil body is hexagonal in shape.

[0010] In a possible design, the radio frequency coil body is wound by a flexible Litz wire and fixed on the radio frequency coil support.

[0011] In a possible design, the radio frequency coil body further comprises a first capacitor, a second capacitor and a third capacitor, one end of the first capacitor is used as an input / output common terminal of the radio frequency coil body, the other end of the first capacitor is electrically connected with one end of the third capacitor, the other end of the third capacitor is used as a ground terminal of the radio frequency coil body, one end of the second capacitor is connected with the other end of the first capacitor, and the other end of the second capacitor is connected with one end of the third capacitor.

[0012] In a possible design, the radio frequency coil support is an arc-shaped plate, the radio frequency coil body is laid on the inner concave side of the radio frequency coil support, and the longest diagonal of the radio frequency coil body is arranged in parallel with the central axis of the radio frequency coil support.

[0013] In a second aspect, the present application discloses a magnetic resonance probe comprising the radio frequency coil according to any one of the above.

[0014] In a possible design, the magnetic resonance probe further comprises a single-sided magnet, and the radio frequency coil support is laid in the middle of one side of the single-sided magnet.

[0015] In a third aspect, the present application discloses a single-sided magnetic resonance imaging system comprising the magnetic resonance probe according to any one of the above.

[0016] In a possible design, the single-sided magnetic resonance imaging system further comprises a spectrometer, a first radio frequency power amplifier, a transceiver and a second radio frequency power amplifier, the input end of the first radio frequency power amplifier and the output end of the second radio frequency power amplifier are electrically connected with the spectrometer, the output end of the first radio frequency power amplifier is electrically connected with the first input end of the transceiver, the first output end of the transceiver is electrically connected with the radio frequency input end of the radio frequency coil body, the second input end of the transceiver is electrically connected with the radio frequency output end of the radio frequency coil body, and the second output end of the transceiver is electrically connected with the input end of the second radio frequency power amplifier.

[0017] The present application has the following beneficial effects:

[0018] The application discloses a radio frequency coil, a magnetic resonance probe and a single-sided magnetic resonance imaging system, and is beneficial to improving the accuracy of single-sided magnetic resonance detection.

[0019] Other advantages of the application will be further described in the specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a structural schematic diagram of an embodiment of the radio frequency coil body;

[0021] Figure 2 is a structural schematic diagram of another embodiment of the radio frequency coil body;

[0022] Figure 3 is a structural schematic diagram of the magnetic resonance probe;

[0023] Figure 4 is a magnetic field distribution schematic diagram of the radio frequency coil body and the single-sided magnet;

[0024] Figure 5 is a module block diagram of the single-sided magnetic resonance imaging system. DETAILED DESCRIPTION

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the application will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the drawings is only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor. It should be noted that the description of these embodiments is used to help understand the application, but does not constitute a limitation on the application.

[0026] Embodiment 1:

[0027] As shown in Figures 1 to 4 The embodiment discloses a radio frequency coil for single-sided magnetic resonance imaging, which comprises a radio frequency coil body 1 and a radio frequency coil support 2, the radio frequency coil body 1 is arranged on the radio frequency coil support 2, and the shape of the radio frequency coil body 1 is a polygon, and any internal angle of the polygon is not 90 degrees. In the embodiment, the radio frequency coil support 2 is used to fix the radio frequency coil body 1.

[0028] It should be noted that the radio frequency coil body 1 is used to transmit and receive radio frequency signals to the liver and other measured tissues of the human body. In the implementation process, the radio frequency pulse transmitted by the radio frequency coil body 1 is used to excite the nuclear spin in the measured human tissue, and then the echo signal returned by the nuclear spin is received.

[0029] In this embodiment, by adjusting the shape of the radio frequency coil body 1, the shape of the radio frequency coil body 1 is polygonal, and any internal angle of the polygon is not 90 degrees. The angle between the B1 field generated by the radio frequency coil body 1 and the B0 field outside the target area is small, and only a low component of the B1 field is orthogonal to the B0 field, and the excitation strength of the atomic nucleus is greatly reduced. At the same time, it can be ensured that the B0 field and the B1 field in the target area are orthogonal, and the B1 field strength is not reduced. In this case, the proportion of the signal in the total signal in the target test area can be greatly improved, and the accuracy of the detection result when the human body is detected by magnetic resonance imaging can be improved.

[0030] Specifically, referring to Figure 4 , according to the figure (a) in Figure 4 , the half height a of the radio frequency coil body 1 is set to 22.5cm, and the half width b is 56.25cm. At this time, the angle between the B0 field and the B1 field is 22°, and the B1 field component B1' orthogonal to the B0 field is B1'=Sin(22°)*B1≈0.374*B1; according to the figure (b) in Figure 4 , the half height a of the radio frequency coil body 1 is set to 25cm, and the half width b is 50.63cm. At this time, the angle between the B0 field and the B1 field is 26°, and the B1 field component B1' orthogonal to the B0 field is B1'=Sin(26°)*B1≈0.438*B1. Based on the above cases, it can be known that based on the shape setting of the radio frequency coil body 1 in this embodiment, only a low component of the B1 field is orthogonal to the B0 field.

[0031] In the implementation process, the ratio of the width and height of the radio frequency coil body 1 can be controlled to reduce the angle between the direction of the coil magnetic field B1 field and the direction of the single-sided magnet magnetic field B0 field, and then the excitation strength of the radio frequency coil in the non-target area is reduced.

[0032] Specifically, in one embodiment, as shown in Figure 1 , the shape of the radio frequency coil body 1 is a rhombus.

[0033] In another embodiment, as shown in Figure 2 , the shape of the radio frequency coil body 1 is a hexagon.

[0034] In this embodiment, the radio frequency coil body 1 is wound by a flexible Litz wire and fixed on the radio frequency coil support 2. It should be noted that the flexible Litz wire is composed of a plurality of thin wires, and winding the radio frequency coil body 1 by the flexible Litz wire can effectively reduce the skin effect in the radio frequency signal, help to improve the efficiency of the radio frequency coil, and reduce energy loss. In addition, the flexible Litz wire has better flexibility than the traditional single wire, which facilitates shape adjustment of the radio frequency coil body 1. After the radio frequency coil body 1 is fixed on the radio frequency coil support 2, the flexible Litz wire can reduce the damage to the structure of the radio frequency coil body 1 caused by external force or vibration, increase the durability and stability of the radio frequency coil body 1, and thus ensure the stability of the imaging performance.

[0035] In this embodiment, the radio frequency coil body 1 further includes a first capacitor C1, a second capacitor C2 and a third capacitor C3. One end of the first capacitor C1 serves as an input and output common terminal of the radio frequency coil body 1, the other end of the first capacitor C1 is electrically connected with one end of the third capacitor C3, the other end of the third capacitor C3 serves as a ground terminal of the radio frequency coil body 1, one end of the second capacitor C2 is connected with the other end of the first capacitor C1, and the other end of the second capacitor C2 is connected with one end of the third capacitor C3. It should be noted that the radio frequency coil body 1 itself can be regarded as an inductor, which has inductive characteristics. In this embodiment, the third capacitor C3 can form a parallel resonant circuit with the radio frequency coil body 1. The parallel resonant circuit can resonate at a specific frequency and amplify the electrical signal at the specific frequency. The third capacitor C3 is used to adjust the resonant frequency to meet the specific circuit requirements. The first capacitor C1 and the second capacitor C2 are in parallel resonant circuit for impedance matching, that is, the first capacitor C1 and the second capacitor C2 can be used to adjust the impedance in the parallel resonant circuit to ensure better transmission of the electrical signal.

[0036] Further, in this embodiment, the radio frequency coil support 2 adopts an arc-shaped plate, the radio frequency coil body 1 is laid on the inner concave side of the radio frequency coil support 2, and the longest diagonal line of the radio frequency coil body 1 is arranged in parallel with the central axis of the radio frequency coil support 2.

[0037] It should be noted that in this embodiment, the radio frequency coil support 2 adopts an arc-shaped plate, which can make the radio frequency coil more conformable to the human body.

[0038] Furthermore, in this embodiment, because the RF coil body 1 is polygonal and none of its internal angles is 90 degrees, the RF coil body 1 has a single, longest diagonal line. Furthermore, the RF coil support 2 is a curved plate, resulting in a central axis. During implementation, the longest diagonal line of the RF coil body 1 is parallel to the central axis of the RF coil support 2, thereby further reducing the component of the B1 field generated by the RF coil that is orthogonal to the B0 field.

[0039] The present invention discloses a radio frequency coil for a unilateral magnetic resonance imaging system. This coil can improve the problem of low detection accuracy of human tissue due to non-ideal excitation regions, thereby enhancing the accuracy of unilateral magnetic resonance imaging. Specifically, in this embodiment, because the radio frequency coil body 1 is polygonal in shape, and none of the internal angles of the polygon is 90 degrees, the radio frequency coil of this embodiment can address the problem of a large proportion of signal from the area outside the liver when performing MRI tests on the human liver using existing square coil magnetic resonance systems. This effectively improves the accuracy of liver MRI system detection without sacrificing signal-to-noise ratio, resulting in higher accuracy in unilateral magnetic resonance imaging.

[0040] Example 2:

[0041] This embodiment discloses a magnetic resonance probe, including the radio frequency coil described in any one of the embodiments 1. Figure 3 and Figure 4 As shown, the magnetic resonance probe further includes a unilateral magnet 3 , and the radio frequency coil support 2 is laid in the middle of one side of the unilateral magnet 3 .

[0042] It should be noted that the unilateral magnet 3 is used to generate a static magnetic field to polarize the nuclear spins in the human tissue being measured, thereby generating a magnetic resonance signal.

[0043] It should also be noted that the working process, working details and technical effects of the magnetic resonance probe provided in this embodiment 2 can be found in embodiment 1 and will not be described in detail here.

[0044] Example 3:

[0045] Based on Example 1 or 2, this embodiment discloses a unilateral magnetic resonance imaging system, including the magnetic resonance probe described in any one of Example 2. Figure 5As shown, the single-sided magnetic resonance imaging system further comprises a spectrometer, a first radio frequency power amplifier, a transceiver and a second radio frequency power amplifier, the input end of the first radio frequency power amplifier and the output end of the second radio frequency power amplifier are electrically connected with the spectrometer, the output end of the first radio frequency power amplifier is electrically connected with the main input end of the transceiver, the input / output common end of the transceiver is electrically connected with the input / output common end of the radio frequency coil body 1, and the main output end of the transceiver is electrically connected with the input end of the second radio frequency power amplifier.

[0046] Specifically, in the embodiment, the spectrometer can control the operation of the entire single-sided magnetic resonance imaging system. During the operation of the single-sided magnetic resonance imaging system, the spectrometer is configured to generate a radio frequency pulse signal and transmit the radio frequency pulse signal to the radio frequency coil body 1 through the first radio frequency power amplifier and the transceiver, and receive echo signals collected by the radio frequency coil body 1 through the second radio frequency power amplifier. In addition, the spectrometer can also realize processing and image reconstruction of the echo signals. The first radio frequency power amplifier is configured to amplify the radio frequency signal generated by the spectrometer to ensure that there is enough power to excite nuclear spins in the human body tissue to be measured. The second radio frequency power amplifier is configured to amplify the echo signals received from the radio frequency coil body 1. The transceiver is configured to realize switching between transmission and reception of the radio frequency signal. In the excitation stage, the transceiver allows the radio frequency signal to be transmitted to the radio frequency coil body 1. In the receiving stage, the transceiver amplifies the echo signals obtained from the human body tissue to be measured through the second radio frequency power amplifier and finally transmits the echo signals to the spectrometer.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A radio frequency coil for unilateral magnetic resonance imaging, characterized in that: The radio frequency coil comprises a radio frequency coil body (1) and a radio frequency coil support (2), wherein the radio frequency coil body (1) is arranged on the radio frequency coil support (2), and the radio frequency coil body (1) is in the shape of a polygon, and any inner angle of the polygon is not 90 degrees, so that the angle between the B1 field generated by the radio frequency coil body (1) and the B0 field outside the target area becomes smaller, thereby reducing the excitation intensity of the atomic nuclei in the target area, and at the same time ensuring that the B0 field and the B1 field in the target area are orthogonal and the B1 field intensity is not reduced, thereby increasing the proportion of the signal in the target test area in the total signal; The radio frequency coil body (1) further includes a first capacitor (C1), a second capacitor (C2) and a third capacitor (C3), one end of the first capacitor (C1) serving as an input and output common end of the radio frequency coil body (1), the other end of the first capacitor (C1) being electrically connected to one end of the third capacitor (C3), the other end of the third capacitor (C3) serving as a ground end of the radio frequency coil body (1), one end of the second capacitor (C2) being connected to the other end of the first capacitor (C1), and the other end of the second capacitor (C2) being connected to one end of the third capacitor (C3); The radio frequency coil body (1) is wound with a flexible Litz wire and is fixedly mounted on the radio frequency coil support (2); The radio frequency coil support (2) is a curved plate, the radio frequency coil body (1) is laid on the concave side of the radio frequency coil support (2), and the longest diagonal line of the radio frequency coil body (1) is arranged parallel to the central axis of the radio frequency coil support (2).

2. The radio frequency coil according to claim 1, characterized in that: The shape of the radio frequency coil body (1) is rhombus.

3. The radio frequency coil according to claim 1, wherein: The shape of the radio frequency coil body (1) is hexagonal.

4. A magnetic resonance probe, characterized in that: Comprising the radio frequency coil according to any one of claims 1 to 3.

5. The magnetic resonance probe according to claim 4, characterized in that: The magnetic resonance probe further comprises a unilateral magnet (3), and the radio frequency coil support (2) is laid in the middle of one side of the unilateral magnet (3).

6. A unilateral magnetic resonance imaging system, characterized in that: The method comprises the magnetic resonance probe according to any one of claims 4 to 5.

7. A unilateral magnetic resonance imaging system according to claim 6, characterized in that: The unilateral magnetic resonance imaging system further includes a spectrometer, a first radio frequency power amplifier, a transceiver converter, and a second radio frequency power amplifier, wherein the input end of the first radio frequency power amplifier and the output end of the second radio frequency power amplifier are both electrically connected to the spectrometer, the output end of the first radio frequency power amplifier is electrically connected to the first input end of the transceiver converter, the first output end of the transceiver converter is electrically connected to the radio frequency input end of the radio frequency coil body (1), the second input end of the transceiver converter is electrically connected to the radio frequency output end of the radio frequency coil body (1), and the second output end of the transceiver converter is electrically connected to the input end of the second radio frequency power amplifier.

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