WO2023082038A1

WO2023082038A1 - Magnetic resonance coil

Info

Publication number: WO2023082038A1
Application number: PCT/CN2021/129477
Authority: WO
Inventors: 李烨; 莫智广; 李楠; 罗超; 杜凤; 陈巧燕; 刘新; 郑海荣
Original assignee: 深圳先进技术研究院
Priority date: 2021-11-09
Filing date: 2021-11-09
Publication date: 2023-05-19

Abstract

A magnetic resonance coil. The magnetic resonance coil comprises a receiving coil (1), a supporting member (2), and a tuning and matching circuit (3); the receiving coil (1) comprises at least two circuit loops (11, 12, 13), and the at least two circuit loops (11, 12, 13) are separately distributed on the supporting member (2); the tuning and matching circuit (3) is provided at one end of the supporting member (2) and is electrically connected to the receiving coil (1). A multi-channel design mode is used for the magnetic resonance coil, and the plurality of channels overlap in pairs, thereby reducing mutual interference between the channels. Compared with a single-channel endorectal coil, the magnetic resonance coil has higher resolution and higher contrast, the signal-to-noise ratio of an endorectal coil is improved, and the imaging quality of the magnetic resonance system is improved; moreover, the magnetic resonance coil has a wider imaging coverage, and thus, the imaging area of the coil better covers the whole part to be examined.

Description

A magnetic resonance coil

technical field

The present application belongs to the technical field of magnetic resonance imaging, and in particular relates to a magnetic resonance coil.

Background technique

Magnetic resonance imaging has become an important imaging method for clinical diagnosis due to its advantages of non-invasive, non-radiation, high resolution, high contrast, and cross-sectional imaging in any orientation.

When performing magnetic resonance imaging, the magnetic resonance system sends magnetic resonance signals to the human body through the transmitting coil, and the human tissue is excited by the signal, and the feedback electromagnetic signal is fed back to the magnetic resonance system through the receiving coil. Among them, the signal strength received by the receiving coil determines the quality of the magnetic resonance imaging to a certain extent. However, since the signal will rapidly attenuate as the distance from the coil increases, it is difficult for the surface coil to obtain high imaging quality for imaging of organs located deep inside the body. Taking prostate imaging as an example, the rectal coil needs to be inserted into the patient's rectum to bring it closer to the prostate, so as to obtain a stronger signal and better image quality than surface coils.

The signal-to-noise ratio is the core parameter of coil design, and a high signal-to-noise ratio means higher resolution and higher contrast, which means better image quality. The coils in the prior art usually only include one channel, and the signal-to-noise ratio is small, so it is difficult to meet the high-resolution imaging requirements. In addition, the single-channel coil has a relatively high signal-to-noise ratio only in the direction perpendicular to it, while the signal-to-noise ratio in other directions is low. The image is blurry.

Contents of the invention

The present application provides a magnetic resonance coil, aiming to solve one of the above-mentioned technical problems in the prior art at least to a certain extent.

In order to solve the above problems, the application provides the following technical solutions:

A magnetic resonance coil, including a receiving coil, a support and a tuning and matching circuit;

The receiving coil includes at least two circuit loops, the at least two circuit loops are respectively distributed on the support, and the at least two circuit loops overlap each other; the tuning and matching circuit is arranged at one end of the support , and is electrically connected to the receiving coil.

The technical solution adopted in the embodiment of the present application further includes: further comprising a coaxial cable and an amplifier, the tuning and matching circuit is connected to the amplifier through the coaxial cable, and the amplifier is connected to the magnetic resonance system.

The technical solution adopted in the embodiment of the present application further includes: the at least two circuit loops are mutually independent in circuit.

The technical solution adopted in the embodiment of the present application further includes: the at least two circuit loops respectively correspond to a port, and the tuning and matching circuit tunes, matches and decouples the corresponding circuit loop through the port.

The technical solution adopted in the embodiment of the present application further includes: the tuning and matching circuit includes the tuning and matching circuit including a first capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a diode, a first inductor, and a first capacitor. Two inductors; the fourth capacitor, the fifth capacitor, the third capacitor and the first capacitor are connected in series, and the at least two circuit loops are decoupled through the first capacitor; the sixth capacitor, the fifth capacitor, the diode and The first inductor is connected in series, and the third capacitor, the second inductor, and the diode are connected in series to form a parallel resonant circuit; when the diode is turned on, the parallel resonant circuit starts to work, so that the corresponding circuit loop It is in an off state; when the diode is off, the second inductor does not work, and the third capacitor works, so that the corresponding circuit loop is in the state of receiving signals.

The technical solution adopted in the embodiment of the present application also includes: the tuning and matching process of the tuning and matching circuit is specifically: after connecting the port to a vector network analyzer through a coaxial cable for calibration, testing the S11 parameter of the port , displayed as the Smith chart mode; add the adjustment mark point as the operating frequency point of the magnetic resonance system, and adjust the size of the third capacitor, the fourth capacitor, and the fifth capacitor by replacing or adjusting the capacitor, so that the mark point moves to Smith The central position of the circular diagram completes the tuning and matching of the tuning and matching circuit.

The technical solution adopted in the embodiment of the present application further includes: the support member is a cylinder with a set diameter.

Compared with the prior art, the beneficial effect of the embodiment of the present application lies in that the magnetic resonance coil of the embodiment of the present application adopts a multi-channel design mode, and multiple channels overlap each other, which reduces the mutual interference between channels. Compared with the single-channel rectal coil, the embodiment of the present application has higher resolution and higher contrast, improves the signal-to-noise ratio of the rectal coil, improves the imaging quality of the magnetic resonance system, and has a wider imaging coverage , so that the imaging area of the coil better covers the entire site to be measured.

Description of drawings

Fig. 1 is a schematic structural diagram of a magnetic resonance coil according to an embodiment of the present application;

Fig. 2 is a circuit connection diagram of the receiving coil 1 of the embodiment of the present application;

Fig. 3 is a flowchart of a magnetic resonance coil imaging method according to an embodiment of the present application.

Detailed ways

In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, not to limit the present application.

Please refer to FIG. 1 , which is a schematic structural diagram of a magnetic resonance coil according to an embodiment of the present application. The magnetic resonance coil of the embodiment of the present application includes a receiving coil 1 , a support 2 , a tuning and matching circuit 3 , a coaxial cable 4 and an amplifier 5 . The receiving coil 1 includes at least two circuit loops. In the embodiment of the present application, three circuit loops are taken as an example, which are respectively the first circuit loop 11, the second circuit loop 12 and the third circuit loop 13. The first circuit loop 11, the second circuit loop The second circuit loop 12 and the third circuit loop 13 are respectively distributed on the support member 2 . The support member 2 is a cylinder with a set diameter (the set diameter is 25 mm in the embodiment of the present application, which can be set according to actual application), and is used to provide support for the receiving coil 1 . The tuning and matching circuit 3 is arranged at one end of the support member 2 and is electrically connected to the receiving coil 1 for performing, tuning, matching and decoupling processing on the receiving coil 1 . The tuning and matching circuit 3 is connected to the amplifier 5 through the coaxial cable 4, and the amplifier 5 is connected to the magnetic resonance system (not shown) through the cable.

Please refer to FIG. 2 , which is a circuit connection diagram of the receiving coil 1 according to the embodiment of the present application. The first circuit loop 11, the second circuit loop 12 and the third circuit loop 13 are independent of each other on the circuit, and the first circuit loop 11 and the second circuit loop 12, the second circuit loop 12 and the third circuit loop 13 alternate in pairs overlap to achieve the purpose of overlap decoupling. The first capacitor C41 is used for decoupling between the first circuit loop 11 and the third circuit loop 13 , and the second capacitor C21 and the tuning and matching circuit of the second circuit loop 12 play a tuning role together. As shown in the figure, the first circuit loop 11, the second circuit loop 12 and the third circuit loop 13 correspond to the first port, the second port and the third port respectively, and the tuning and matching circuit 3 passes through the first port, the second port and the third port respectively. The third port adjusts the first circuit loop 11 , the second circuit loop 12 and the third circuit loop 13 to achieve the effects of tuning, matching and preamplifier decoupling. The tuning and matching circuit structures of the first circuit loop 11, the second circuit loop 12 and the third circuit loop 13 are the same. Taking the first circuit loop 11 as an example, the circuit structure of the tuning and matching circuit 3 includes: the third capacitor C12, the fourth capacitor Cf1, the fifth capacitor Cp1, the sixth capacitor Cs1, the diode D1, the first inductor L11 and the second inductor L12; the fourth capacitor Cf1, the fifth capacitor Cp1, the third capacitor C12 and the first capacitor C41 are connected in series. The six capacitors Cs1, the fifth capacitor Cp1, the diode D1 and the first inductor L11 are connected in series, and the third capacitor C12, the second inductor L12 and the diode D1 are connected in series to form a parallel resonant circuit; the diode D1 functions as a direct current, AC isolation; the fourth capacitor Cf1, the fifth capacitor Cp1 and the sixth capacitor Cs1 jointly determine the tuning and matching of the circuit. When the diode D1 is turned on, the parallel resonant circuit composed of the third capacitor C12 and the second inductance L12 starts to work, and the first circuit loop 11 is in a disconnected state at this time, so as to avoid the excitation signal of the magnetic resonance system from damaging the circuit; when the diode D1 When disconnected, the second inductor L12 does not work, the third capacitor C12 works, and the first circuit loop 11 is in a normal state of receiving signals.

The tuning and matching circuit structures of the second circuit loop 12 and the third circuit loop 13 are the same as those of the first circuit loop 11 , and will not be repeated in this application.

In the embodiment of the present application, taking the first circuit loop 11 as an example, the tuning and matching process of the tuning and matching circuit is specifically: after connecting the first port to a vector network analyzer through a coaxial cable for calibration, then testing the first port S11 parameter, displayed as Smith chart mode, add the adjustment mark point marker as the working frequency point of the magnetic resonance system, adjust the size of Cf1, Cp1 and Cs1 by replacing the capacitor or adjusting the adjustable capacitor, so that the marker point marker moves to Smith The center position of the circular diagram completes the tuning and matching of the tuning matching circuit. The tuning and matching processes of the second circuit loop 12 and the third circuit loop 13 are the same as those of the first circuit loop 11 , which will not be repeated in this application.

Please refer to FIG. 3 , which is a flow chart of the magnetic resonance coil imaging method according to the embodiment of the present application. The magnetic resonance coil imaging method of the embodiment of the present application includes the following steps:

S1: Place the receiving coil on the part of the subject to be tested;

Among them, taking the detection of the prostate as an example, the coil is inserted into the rectum of the subject to be tested.

S2: Detect whether the tuning, matching and cross-coupling of the receiving coil are normal, if not, go to S3; otherwise, go to S4;

S3: Adjust the capacitance of the tuning and matching circuit, and re-execute S2;

S4: Connect the receiving coil to the magnetic resonance system, and perform magnetic resonance scanning imaging of the part to be measured through the magnetic resonance system.

Based on the above, the magnetic resonance coil of the embodiment of the present application adopts a multi-channel design mode, and multiple channels are overlapped in pairs to reduce mutual interference between channels. Compared with the single-channel rectal coil, the embodiment of the present application has higher resolution and higher contrast, improves the signal-to-noise ratio of the rectal coil, improves the imaging quality of the magnetic resonance system, and has a wider imaging coverage , so that the imaging area of the coil better covers the entire site to be measured.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined in this application may be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the present application will not be limited to the embodiments shown in the present application, but is to be accorded the widest scope consistent with the principles and novel features disclosed in the present application.

Claims

A magnetic resonance coil, characterized in that it includes a receiving coil, a support and a tuning and matching circuit;

The receiving coil includes at least two circuit loops, the at least two circuit loops are respectively distributed on the support, and the at least two circuit loops overlap each other; the tuning and matching circuit is arranged at one end of the support , and is electrically connected to the receiving coil.
The magnetic resonance coil according to claim 1, further comprising a coaxial cable and an amplifier, the tuning and matching circuit is connected to the amplifier through the coaxial cable, and the amplifier is connected to the magnetic resonance system.
The magnetic resonance coil according to claim 1, wherein the at least two circuit loops are electrically independent from each other.
The magnetic resonance coil according to any one of claims 1 to 3, wherein the at least two circuit loops correspond to one port respectively, and the tuning and matching circuit tunes, matches and removes the corresponding circuit loops through the ports. couple.
The magnetic resonance coil according to claim 4, wherein the tuning and matching circuit comprises a first capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a diode, a first inductor and a second inductor The fourth capacitor, the fifth capacitor, the third capacitor and the first capacitor are connected in series, and the at least two circuit loops are decoupled through the first capacitor; the sixth capacitor, the fifth capacitor, the diode and the first The inductor is connected in series, and the third capacitor, the second inductor and the diode are connected in series to form a parallel resonant circuit; when the diode is turned on, the parallel resonant circuit starts to work, so that the corresponding circuit loop is in an off state. On state; when the diode is disconnected, the second inductor does not work, and the third capacitor works, so that the corresponding circuit loop is in the state of receiving signals.
The magnetic resonance coil according to claim 5, wherein the tuning and matching process of the tuning and matching circuit is specifically: after connecting the port to a vector network analyzer through a coaxial cable for calibration, testing the The S11 parameter of the port is displayed in the Smith chart mode; add the adjustment mark point as the working frequency point of the magnetic resonance system, and adjust the size of the third capacitor, the fourth capacitor, and the fifth capacitor by replacing or adjusting the capacitor, so that the mark The point is moved to the center of the Smith chart to complete the tuning and matching of the tuning and matching circuit.
The magnetic resonance coil according to claim 1, wherein the support member is a cylinder with a set diameter.