WO2021097940A1 - Multi-channel radio frequency coil device and magnetic resonance imaging system - Google Patents

Abstract

A multi-channel radio frequency coil device (300) and a magnetic resonance imaging (MRI) system. The multi-channel radio frequency coil device (300) comprises: at least two adjacent radio frequency coils (110, 210, 310), the at least two radio frequency coils (110, 210, 310) being used for generating a magnetic resonance (MR) signal and/or receiving the MR signal; and a decoupling circuit (120, 220, 320) provided between the two adjacent radio frequency coils (110, 210, 310) and used for regulating an induced current of the at least two radio frequency coils (110, 210, 310). The decoupling circuit (120, 220, 320) is provided between the two adjacent radio frequency coils (110, 210, 310), so that the effect of improving imaging integrity while ensuring decoupling performance is achieved.

Description

Multi-channel radio frequency coil device and nuclear magnetic resonance imaging system

This disclosure claims the priority of a Chinese patent application filed with the Chinese Patent Office with an application number of 201911140417.7 on November 20, 2019, and the entire content of the above application is incorporated into this disclosure by reference.

Technical field

The embodiment of the present invention relates to the field of magnetic resonance technology, for example, to a multi-channel radio frequency coil device and a nuclear magnetic resonance imaging system.

Background technique

Aproton MRI plays an important role in the process of cell growth and can obtain important morphological and metabolic information.

When using multi-channel radio frequency coils for imaging, it is necessary to decouple the coils between adjacent channels. The decoupling performance is critical to the efficiency of the coil array and the parallel imaging performance. In the related art, the coils between adjacent channels mainly solve the problem of electromagnetic coupling between the coil channels through geometric overlap technology (operating magnetic fields to overlap to make the mutual inductance of the two coils zero).

However, in the related art, in the manner of decoupling, the overlapping part between the coils of adjacent channels cannot be used for imaging, which will result in incomplete imaging.

Summary of the invention

The embodiment of the present invention provides a multi-channel radio frequency coil device and a nuclear magnetic resonance imaging system to achieve the effect of improving the integrity of imaging on the premise of ensuring the decoupling performance.

In the first aspect, an embodiment of the present invention provides a multi-channel radio frequency coil device, including:

At least two radio frequency coils arranged adjacently, the at least two radio frequency coils are used for generating and/or receiving nuclear magnetic resonance MR signals;

The decoupling loop is arranged between two adjacent radio frequency coils and is configured to adjust the induced current of at least two radio frequency coils.

Optionally, the decoupling loop includes at least one first capacitor, and the first capacitor is configured to adjust the induced current of the at least two radio frequency coils.

Optionally, the decoupling loop includes a plurality of first capacitors connected in series, and the plurality of first capacitors are evenly distributed in the decoupling loop.

Optionally, the capacitance values of the plurality of first capacitors are equal.

Optionally, the radio frequency coil is a dual-tuned radio frequency coil.

Optionally, the dual-tuned radio frequency coil includes:

Basic coil and a resonant circuit;

The basic coil includes a plurality of second capacitors connected in series;

The resonance circuit is connected in parallel to both ends of a second capacitor among the plurality of second capacitors.

Optionally, the length of the decoupling loop and the base coil in the first direction are the same.

Optionally, the at least two radio frequency coils are distributed on a cylindrical surface.

Optionally, the at least two radio frequency coils are distributed on a plane.

In the second aspect, an embodiment of the present invention provides a nuclear magnetic resonance imaging system, including the multi-channel radio frequency coil device described in any embodiment of the present application.

The multi-channel radio frequency coil device of the embodiment of the present invention includes a radio frequency coil group and a decoupling circuit; the radio frequency coil group includes at least two radio frequency coils arranged adjacently, and the at least two radio frequency coils are used to generate nuclear magnetic resonance MR signals, And/or receive the nuclear magnetic resonance MR signal; the decoupling loop is arranged between two adjacent radio frequency coils, and is used to adjust the induced current of at least two radio frequency coils, which solves the overlap between the coils of adjacent channels and cannot Used for imaging, it will cause the problem of incomplete imaging, and the effect of improving the integrity of imaging under the premise of ensuring decoupling performance is realized.

Description of the drawings

FIG. 1 is a schematic structural diagram of a multi-channel radio frequency coil device according to Embodiment 1 of the present invention;

2 is a schematic structural diagram of the arrangement of three radio frequency coils and decoupling loops according to Embodiment 1 of the present invention;

3 is a schematic diagram of at least two radio frequency coils distributed on a cylindrical surface according to Embodiment 1 of the present invention;

4 is a schematic structural diagram of a multi-channel radio frequency coil device according to Embodiment 2 of the present invention;

FIG. 5 is a schematic structural diagram of a nuclear magnetic resonance imaging system according to Embodiment 3 of the present invention.

Detailed ways

The application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described here are only used to explain the application, but not to limit the application. In addition, it should be noted that, for ease of description, the drawings only show a part of the structure related to the present application instead of all of the structure.

In addition, the terms "first", "second", etc. may be used herein to describe various directions, actions, steps or elements, etc., but these directions, actions, steps or elements are not limited by these terms. These terms are only used to distinguish a first direction, action, step or element from another direction, action, step or element. For example, without departing from the scope of the present application, the first capacitor may be referred to as the second capacitor, and similarly, the second capacitor may be referred to as the first capacitor. Both the first capacitor and the second capacitor are capacitors, but they are not the same capacitor. The terms "first", "second", etc. cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present application, "a plurality of" means at least two, such as two, three, etc., unless specifically defined otherwise.

Example one

FIG. 1 is a schematic structural diagram of a multi-channel radio frequency coil device provided by Embodiment 1 of the present invention. As shown in FIG. 1, an embodiment of the present invention provides a multi-channel radio frequency coil device, which includes at least two radio frequency coils 110 and a decoupling circuit 120. The multi-channel radio frequency coil device of this embodiment is used to generate nuclear magnetic resonance MR signals and/or receive nuclear magnetic resonance MR signals. among them:

The at least two radio frequency coils 110 are used to generate nuclear magnetic resonance MR signals and/or receive nuclear magnetic resonance MR signals;

The decoupling loop 120 is arranged between two adjacent radio frequency coils 110 for adjusting the induced current of at least two radio frequency coils 110.

In this embodiment, the greater the number of radio frequency coils 110, the more accurate the imaging, and the number can be set as required. In some embodiments, when MRI (Magnetic Resonance Imaging) is used for imaging, MRI applies radio frequency pulses of a certain frequency to the human body in a static magnetic field, so that the hydrogen protons in the human body are excited to generate magnetic resonance. Resonance phenomenon. After the pulse is stopped, the proton generates an MR (Magnetic Resonance) signal during the relaxation process. Through the processing of MR signal reception, spatial coding and image reconstruction. The at least two radio frequency coils 110 of this embodiment are used to simultaneously generate and/or receive nuclear magnetic resonance MR signals. That is, the radio frequency coil 110 can be an element that separately applies radio frequency pulses of a specific frequency to generate MR signals; it can also be an element that receives MR signals alone; it can also be an element that generates MR signals and also serves as an element that receives MR signals. . Optionally, the radio frequency coil 110 is a metal piece. Optionally, the radio frequency coil 110 is copper. Optionally, the at least two radio frequency coils 110 may be distributed on a cylindrical surface or on a plane.

In this embodiment, optionally, the radio frequency coil 110 may be a single tuned radio frequency coil 110 or a double tuned radio frequency coil 110. The single-tuned radio frequency coil 110 refers to an element for generating MR signals at a single frequency, or an element for receiving MR signals generated at a single frequency. The dual-tuned radio frequency coil 110 refers to an element that can generate or receive MR signals of two frequencies. Optionally, the dual-tuned radio frequency coil 110 may be ^{a dual-tuned radio frequency coil 110 of any two nuclides of 1} H, ¹⁹ F, ³¹ P, ²³ Na, ¹³ C, and ¹⁹ K, for example, the dual-tuned radio frequency coil 110 of the nuclides ¹ H and ¹⁹ F. Tuning the radio frequency coil 110.

In this embodiment, the decoupling circuit 120 is arranged between two adjacent radio frequency coils 110, and is used to adjust the induced current generated by at least two coils during operation, so as to prevent the radio frequency coils 110 adjacent to each other from interfering with each other, thereby improving The efficiency and parallel imaging performance of the radio frequency coil 110 group. Optionally, the distance between the decoupling loop 120 and two adjacent radio frequency coils 110 is equal. As an independent component, the decoupling loop 120 can compensate or eliminate the induced current generated by the mutual coupling between adjacent radio frequency coils 110. In some embodiments, the decoupling loop 120 generates a uniform current distribution in the decoupling loop 120 when decoupling two adjacent radio frequency coils 110. The decoupling circuit 120 is arranged between two adjacent radio frequency coils 110, and there is no contact between the decoupling circuit 120 and the radio frequency coil 110. A decoupling circuit 120 is provided between two adjacent radio frequency coils 110. Referring to FIG. 2, FIG. 2 is a schematic structural diagram of the arrangement of three radio frequency coils and a decoupling loop provided by this embodiment. It can be seen from FIG. 2 that there are three radio frequency coils 110 A, B, and C, where A and B are adjacent, and B and C are adjacent, so a decoupling circuit 120 is provided between A and B, and a decoupling circuit 120 is provided between B and C. There is a decoupling circuit 120.

In an embodiment, optionally, at least two radio frequency coils 110 are distributed on a cylindrical surface, and then at least two radio frequency coils 110 are adjacent to each other. In some embodiments, the symmetry axes of two adjacent radio frequency coils 110 are parallel to the central axis of the cylindrical surface where they are located. Referring to Fig. 3, Fig. 3 is a schematic diagram of at least two radio frequency coils distributed on a cylindrical surface. It can be seen from FIG. 3 that the symmetry axes of two adjacent radio frequency coils 120 are parallel to the central axis of the cylindrical surface where they are located. Optionally, at least two radio frequency coils 110 are evenly distributed on the cylindrical surface. Exemplarily, there are three radio frequency coils 110, A, B, and C, where A and B are adjacent, B and C are adjacent, and C and A are adjacent, then a decoupling circuit 120 is provided between A and B at this time. , A decoupling circuit 120 is also provided between B and C, and a decoupling circuit 120 is also provided between A and C.

According to the technical solution of the embodiment of the present invention, the multi-channel radio frequency coil device includes at least two radio frequency coils arranged adjacently, and the at least two radio frequency coils are used for generating and/or receiving nuclear magnetic resonance MR signals; decoupling A loop, the decoupling loop is arranged between two adjacent radio frequency coils, and is used to adjust the induced current of at least two radio frequency coils. Since the decoupling loop is independently arranged between two adjacent radio frequency coils, there is no geometric overlap between two adjacent radio frequency coils, and the decoupling loop can compensate or eliminate the induced current caused by coupling between two adjacent coils. To achieve the technical effect of improving the integrity of imaging under the premise of ensuring decoupling performance. In addition, there is no physical structure connection between the decoupling loop and the radio frequency coil, which greatly improves the convenience of layout of the radio frequency coil.

Example two

FIG. 4 is a schematic structural diagram of a multi-channel radio frequency coil device according to Embodiment 2 of the present invention. This embodiment is a modification of the above technical solution. The multi-channel radio frequency coil device of this embodiment is used to generate and/or receive nuclear magnetic resonance MR signals. As shown in FIG. 4, an embodiment of the present invention provides a multi-channel radio frequency coil device, which includes at least two radio frequency coils 210 and a decoupling circuit 220. among them:

The at least two radio frequency coils 210 are used to generate nuclear magnetic resonance MR signals and/or receive nuclear magnetic resonance MR signals;

The decoupling loop 220 is arranged between two adjacent radio frequency coils 210 and is used to adjust the induced current of at least two radio frequency coils 210. The decoupling loop 220 includes at least one first capacitor 221, and the first capacitor 221 It is used to adjust the induced current of at least two radio frequency coils 210.

Optionally, the number and arrangement of the first capacitors 221 and the capacitance value of each first capacitor 221 can be determined according to the best effect of the simulation.

In an embodiment, optionally, the decoupling circuit 220 includes a plurality of first capacitors 221 connected in series, and the plurality of first capacitors 221 are evenly distributed in the decoupling circuit 220. The plurality of first capacitors 221 are evenly distributed in the decoupling loop 220, which is more uniform when supplementing or eliminating the induced current generated by the coupling between two adjacent coils, and the effect of achieving decoupling is better. Optionally, the capacitance values of the plurality of first capacitors 221 are equal. Exemplarily, the decoupling loop 220 is a rectangular loop with a size of 22X80mm. The decoupling loop 220 includes 6 first capacitors 221 evenly distributed. The capacitance value of each first capacitor 221 is 110PF, and the decoupling loop 220 phase The size of the two adjacent radio frequency coils 210 is 80×80 mm, and the distance between the decoupling circuit 220 and the adjacent two radio frequency coils 210 is 4 mm. At this time, the isolation of the adjacent radio frequency coils 210 is less than -20 dB.

It should be noted that the above is only a form that can be implemented, and other forms of construction can be realized. The number and capacitance value of the first capacitor 221 or the decoupling circuit 220 and adjacent radio frequency coils can be adjusted through the simulation results. 210 distance.

In this embodiment, the number of the first capacitor 221 in the decoupling loop 220 is at least one, and there may be more than one. In some embodiments, the induced current generated by the coupling between two adjacent radio frequency coils 210 during operation is absorbed by the first capacitor 221 in the decoupling loop 220, so as to compensate or eliminate the coupling between two adjacent coils. The induced current generated. Optionally, the number of the first capacitors 221 can be determined by simulation to determine an optimal number.

In this embodiment, the radio frequency coil 210 is a dual-tuned radio frequency coil 210. The dual-tuned radio frequency coil 210 refers to an element that can generate or receive MR signals of two frequencies. Optionally, the dual-tuned radio frequency coil 210 may be a dual-tuned radio-frequency coil 210 of ^{any two nuclides of 1} H, ¹⁹ F, ³¹ P, ²³ Na, ¹³ C, and ¹⁹ K, for example, the dual-tuned radio frequency coil 210 of the nuclides ¹ H and ¹⁹ F. Tuning the radio frequency coil 210. Exemplarily, in the 3T system, the ¹ H and ¹⁹ F resonance frequencies are 123.2 MHz and 115.9 MHz, respectively.

Among them, the dual-tuned radio frequency coil 210 includes a basic coil and a resonant circuit 211;

The basic coil includes a plurality of second capacitors connected in series;

The resonance circuit 211 is connected in parallel to both ends of a second capacitor among the plurality of second capacitors.

Optionally, a plurality of second capacitors are evenly distributed in the basic coil, and the resonance circuit 211 is connected in parallel to both ends of one of the plurality of second capacitors. In this embodiment, optionally, the shape of the basic coil may be a regular shape such as a rectangle or a circle. Optionally, the resonant circuit 211 includes an excitation port 2111, a first resonant capacitor C1, a second resonant capacitor C2, a third resonant capacitor C3, a fourth resonant capacitor C4, a fifth resonant capacitor C5, and an inductor L1. The first capacitor 221, the excitation port 2111, and the third capacitor are sequentially connected in series to form a first series branch, the inductor L1 is connected in parallel with the first series branch, the fifth capacitor is connected in parallel with the inductor L1, and the second capacitor is connected with the fourth capacitor and the fifth capacitor. Concatenated. The excitation port 2111 is used to connect with an excitation source or a receiving system. If the excitation port 2111 is connected to an excitation source, the dual-tuned radio frequency coil 210 is used to generate MR signals, and if the excitation port 2111 is connected to a receiving system, the dual-tuned radio frequency coil 210 is used to receive MR signals. In some embodiments, a switch component can be provided to switch between the functions of generating and receiving MR signals.

Optionally, the length of the decoupling loop 220 and the base coil in the first direction are the same. In some embodiments, the length of the first direction is the direction of the side connected to the resonance.

According to the technical solution of the embodiment of the present invention, the multi-channel radio frequency coil device includes at least two radio frequency coils arranged adjacently, and the at least two radio frequency coils are used for generating and/or receiving nuclear magnetic resonance MR signals; decoupling A loop, the decoupling loop is arranged between two adjacent radio frequency coils, and is used to adjust the induced current of at least two radio frequency coils. Since the decoupling loop is independently arranged between two adjacent radio frequency coils, there is no geometric overlap between two adjacent radio frequency coils, and the decoupling loop can compensate or eliminate the induced current caused by coupling between two adjacent coils. To achieve the technical effect of improving the integrity of imaging under the premise of ensuring decoupling performance. In addition, the radio frequency coil in this embodiment is a double-tuned radio frequency coil, which also overcomes the coupling problem between different nuclides and improves the accuracy of imaging.

Example three

FIG. 5 is a schematic structural diagram of the nuclear magnetic resonance imaging system provided by the third embodiment of the present invention. As shown in FIG. 5, an embodiment of the present invention provides a nuclear magnetic resonance imaging system 30 including a multi-channel radio frequency coil device 300. among them:

The multi-channel radio frequency coil device 300 includes at least two radio frequency coils 310 and a decoupling circuit 320;

The at least two radio frequency coils 310 are used to generate nuclear magnetic resonance MR signals and/or receive nuclear magnetic resonance MR signals;

The decoupling loop 320 is arranged between two adjacent radio frequency coils 310 to adjust the induced current of at least two radio frequency coils 310.

In this embodiment, the greater the number of radio frequency coils 310, the more accurate the imaging, and the number can be set as required. In some embodiments, when MRI (Magnetic Resonance Imaging) is used for imaging, MRI applies radio frequency pulses of a certain frequency to the human body in a static magnetic field, so that the hydrogen protons in the human body are excited to generate magnetic resonance. Resonance phenomenon. After the pulse is stopped, the proton generates an MR (Magnetic Resonance) signal during the relaxation process. Through the processing of MR signal reception, spatial coding and image reconstruction. The at least two radio frequency coils 310 of this embodiment are used to simultaneously generate and/or receive nuclear magnetic resonance MR signals. That is, the radio frequency coil 310 can be an element that separately applies radio frequency pulses of a specific frequency to generate MR signals; it can also be an element that receives MR signals separately; it can also be an element that generates MR signals and also serves as an element that receives MR signals. . Optionally, the radio frequency coil 310 is a metal piece. Optionally, the radio frequency coil 310 is made of copper. Optionally, the at least two radio frequency coils 310 may be distributed on a cylindrical surface, or may be distributed on a plane.

In this embodiment, optionally, the radio frequency coil 310 may be a single tuned radio frequency coil 310 or a double tuned radio frequency coil 310. The single-tuned radio frequency coil 310 refers to an element for generating MR signals at a single frequency, or an element for receiving MR signals generated at a single frequency. The dual-tuned radio frequency coil 310 refers to an element that can generate or receive MR signals of two frequencies. Optionally, the dual-tuned radio frequency coil 310 can be a dual-tuned radio-frequency coil 310 of ^{any two nuclides of 1} H, ¹⁹ F, ³¹ P, ²³ Na, ¹³ C, and ¹⁹ K, for example, the dual-tuned radio frequency coil 310 of the nuclides ¹ H and ¹⁹ F. Tuning the radio frequency coil 310.

In this embodiment, the decoupling circuit 320 is arranged between two adjacent radio frequency coils 310, and is used to adjust the induced current generated by at least two coils during operation, so as to prevent the radio frequency coils 310 adjacent to each other from interfering with each other, thereby improving The efficiency and parallel imaging performance of the radio frequency coil 310 group. As an independent component, the decoupling loop 320 can compensate or eliminate the induced current generated by the mutual coupling between adjacent radio frequency coils 310. In some embodiments, the decoupling loop 320 generates a uniform current distribution in the decoupling loop 320 when decoupling two adjacent radio frequency coils 310. The decoupling circuit 320 is arranged between two adjacent radio frequency coils 310, and there is no contact between the decoupling circuit 320 and the radio frequency coil 310. A decoupling loop 320 is provided between two adjacent radio frequency coils 310. Exemplarily, there are three radio frequency coils 310, A, B, and C, where A and B are adjacent, and B and C are adjacent, then a decoupling circuit 320 is provided between A and B, and a decoupling circuit 320 is provided between B and C. Decoupling loop 320.

In an embodiment, optionally, at least two radio frequency coils 310 are distributed on the cylindrical surface, and then at least two radio frequency coils 310 are adjacent to each other. Exemplarily, there are three radio frequency coils 310, A, B, and C, where A and B are adjacent, B and C are adjacent, and C and A are adjacent, then a decoupling loop 320 is provided between A and B at this time. , A decoupling loop 320 is also provided between B and C, and a decoupling loop 320 is also provided between A and C.

According to the technical solution of the embodiment of the present invention, the nuclear magnetic resonance imaging system includes a multi-channel radio frequency coil device, and the multi-channel radio frequency coil device includes at least two radio frequency coils arranged adjacently, and the at least two radio frequency coils are used to generate nuclear magnetic resonance MR signals, And/or receiving a nuclear magnetic resonance MR signal; a decoupling loop, the decoupling loop is arranged between two adjacent radio frequency coils, and is used to adjust the induced current of at least two radio frequency coils. Since the decoupling loop is independently arranged between two adjacent radio frequency coils, there is no geometric overlap between two adjacent radio frequency coils, and the decoupling loop can compensate or eliminate the induced current caused by coupling between two adjacent coils. To achieve the technical effect of improving the integrity of imaging under the premise of ensuring decoupling performance. In addition, there is no physical structure connection between the decoupling loop and the radio frequency coil, which greatly improves the convenience of layout of the radio frequency coil.

Claims (10)

1. A multi-channel radio frequency coil device includes:

   At least two radio frequency coils arranged adjacently, the at least two radio frequency coils are used for generating and/or receiving nuclear magnetic resonance MR signals;

   The decoupling loop is arranged between two adjacent radio frequency coils and is configured to adjust the induced current of at least two radio frequency coils.
2. The multi-channel radio frequency coil device according to claim 1, wherein the decoupling circuit includes at least one first capacitor, and the first capacitor is configured to adjust the induced current of the at least two radio frequency coils.
3. 3. The multi-channel radio frequency coil device of claim 2, wherein the decoupling loop comprises a plurality of first capacitors connected in series, and the plurality of first capacitors are evenly distributed in the decoupling loop.
4. The multi-channel radio frequency coil device of claim 3, wherein the capacitance values of the plurality of first capacitors are equal.
5. The multi-channel radio frequency coil device of claim 1, wherein the radio frequency coil is a dual-tuned radio frequency coil.
6. The multi-channel radio frequency coil device of claim 5, wherein the dual-tuned radio frequency coil comprises:

   Basic coil and a resonant circuit;

   The basic coil includes a plurality of second capacitors connected in series;

   The resonance circuit is connected in parallel to both ends of a second capacitor among the plurality of second capacitors.
7. The multi-channel radio frequency coil device according to claim 6, wherein the length of the decoupling loop and the base coil in the first direction are the same.
8. The multi-channel radio frequency coil device according to any one of claims 1-7, wherein the at least two radio frequency coils are distributed on a cylindrical surface.
9. The multi-channel radio frequency coil device according to any one of claims 1-7, wherein the at least two radio frequency coils are distributed on a plane.
10. A nuclear magnetic resonance imaging system, comprising the multi-channel radio frequency coil device according to any one of claims 1-9.

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