CN110109035B

CN110109035B - Birdcage coil decoupling device, birdcage coil decoupling system and magnetic resonance system

Info

Publication number: CN110109035B
Application number: CN201910323537.4A
Authority: CN
Inventors: 吴敏; 方福衣
Original assignee: Shanghai United Imaging Healthcare Co Ltd
Current assignee: Shanghai United Imaging Healthcare Co Ltd
Priority date: 2019-04-22
Filing date: 2019-04-22
Publication date: 2021-05-18
Anticipated expiration: 2039-04-22
Also published as: CN110109035A

Abstract

The application relates to a birdcage coil decoupling device, a birdcage coil decoupling system and a magnetic resonance system. The birdcage coil decoupling device is formed by connecting a plurality of combiners in series end to end, and decoupling of the multi-coil port birdcage coil is realized. In addition, each coil port can independently control the phase and amplitude of the signal, so that the uniformity of the radio frequency excitation magnetic field generated by the birdcage coil is higher.

Description

Birdcage coil decoupling device, birdcage coil decoupling system and magnetic resonance system

Technical Field

The application relates to the technical field of magnetic resonance medical treatment, in particular to a birdcage coil decoupling device, a birdcage coil decoupling system and a magnetic resonance system.

Background

Birdcage radio frequency coils, also known as birdcage coils, use the principle of standing LC wave resonance to generate a uniform radio frequency excitation magnetic field for magnetic resonance excitation. In the using process of the birdcage coil, power signals are fed in through two feed ports of the birdcage coil, and radio frequency signals with the phase difference of 90 degrees are input, so that a circularly polarized magnetic field is generated. The feed locations are typically located on capacitors located at two orthogonal positions of the birdcage coil end-rings, so that the birdcage coils of the two feed ports are decoupled naturally, and power signal isolation between the two feed ports can be achieved without additional decoupling means.

However, a birdcage coil with more than two feed ports, such as a four-port birdcage coil, has a strong coupling of signals between the feed ports. If the birdcage coil is not decoupled, the power signal in the input feed port is coupled from one power amplifier to another, so that the operating efficiency of the birdcage coil is reduced, and even other power sources are damaged.

In the traditional scheme, a decoupling method and a decoupling device which are formed and aim at a multi-port birdcage coil are not provided.

Disclosure of Invention

Therefore, it is necessary to provide a birdcage coil decoupling device, a birdcage coil decoupling system, and a magnetic resonance system, in order to solve the problem that a decoupling method and a decoupling device for a multi-port birdcage coil are not formed in the conventional scheme.

The application provides a birdcage coil decoupling zero device uses with the cooperation of birdcage coil, birdcage coil decoupling zero device respectively with birdcage coil and power supply electricity are connected. In one embodiment, the birdcage coil decoupling apparatus includes:

the combiner unit comprises a plurality of combiners which are connected in series end to form the combiner unit;

the input end of the combining unit is electrically connected with the power supply and is used for receiving a power signal generated by the power supply;

the output end of the combining unit is electrically connected with the birdcage coil and used for transmitting and distributing the power signals to a plurality of coil ports of the birdcage coil so as to realize the decoupling of the birdcage coil.

In this embodiment, through setting up the birdcage coil decoupling zero device that a plurality of combiners end to end series constitute, realized the decoupling zero of many coil ports birdcage coil. In addition, each coil port can independently control the phase and amplitude of the signal, so that the uniformity of the radio frequency magnetic field generated by the birdcage coil is higher.

The application also provides a birdcage coil decoupling system. In one embodiment, the birdcage coil decoupling system includes:

a power supply for generating a power signal;

a birdcage coil decoupling device as mentioned in the foregoing, an input terminal of the birdcage coil decoupling device being electrically connected to the power supply for receiving a power signal generated by the power supply;

the birdcage coil is provided with a plurality of coil ports and is electrically connected with the output end of the birdcage coil decoupling device through the coil ports;

the birdcage coil decoupling device is further configured to transmit and distribute the power signal to a plurality of coil ports of the birdcage coil to achieve decoupling of the birdcage coil.

In this embodiment, through setting up the birdcage coil structural system who comprises power supply, birdcage coil and birdcage coil decoupling zero device, realized the decoupling zero to many coil ports birdcage coil. In addition, each coil port can independently control the phase and amplitude of the signal, so that the uniformity of the radio frequency magnetic field generated by the birdcage coil is higher.

The application also provides a magnetic resonance system based on the birdcage coil structure. In one embodiment, the magnetic resonance system based on a birdcage coil structure includes:

a radio frequency module comprising a birdcage coil; the birdcage coil is used for generating a radio frequency magnetic field;

a gradient module comprising gradient coils; the gradient coil is sleeved outside the birdcage coil and is used for generating a gradient magnetic field;

the magnet module is sleeved outside the gradient coil and used for generating a main magnetic field;

a birdcage coil decoupling device as mentioned in the foregoing, electrically connected to the birdcage coil, for performing a decoupling operation on the birdcage coil;

the power supply is electrically connected with the birdcage coil decoupling device and used for generating a power signal and sending the power signal to the birdcage coil decoupling device;

the controller is electrically connected with the birdcage coil decoupling device and/or the gradient module and is used for controlling the radio frequency module to generate the radio frequency magnetic field and/or the gradient module to generate the gradient magnetic field;

and the upper computer is in communication connection with the controller and is used for transmitting scanning sequence instructions to the controller so as to control the magnetic resonance system to operate and generate magnetic resonance images.

In this embodiment, through the setting magnetic resonance system that has birdcage coil decoupling assembly, realized the decoupling zero of many coil ports birdcage coil for whole magnetic resonance system normal operating. In addition, the number of the feed ports of the birdcage coil is increased, and the number of the power amplifiers in the power supply is correspondingly increased, so that the maximum output power of every other power amplifier is reduced, and the load pressure of the power amplifiers is relieved.

Drawings

Fig. 1 is a schematic structural diagram of a birdcage coil decoupling apparatus provided in an embodiment of the present application;

fig. 2 is a diagram illustrating a usage state of a birdcage coil decoupling apparatus provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of a birdcage coil decoupling apparatus provided in an embodiment of the present application;

FIG. 4 is a schematic diagram illustrating an end ring distribution of a plurality of coil ports on a birdcage coil upper end ring in the birdcage coil decoupling apparatus provided in an embodiment of the present application;

fig. 5 is a schematic structural diagram of a birdcage coil decoupling apparatus applied to a four-port birdcage coil according to an embodiment of the present application;

fig. 6 is a diagram illustrating a usage state of a birdcage coil decoupling apparatus applied to a four-port birdcage coil according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a same-frequency combiner in the birdcage coil decoupling device according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a birdcage coil decoupling apparatus applied to a three-port birdcage coil according to an embodiment of the present application;

FIG. 9 is a schematic structural diagram of a birdcage coil decoupling system provided in an embodiment of the present application;

FIG. 10 is a schematic signal transmission diagram of a birdcage coil decoupling system provided in an embodiment of the present application;

fig. 11 is a schematic structural diagram of a magnetic resonance system based on a birdcage coil structure according to an embodiment of the present application.

Reference numerals:

10 birdcage coil decoupling system

Magnetic resonance system based on birdcage coil structure

100 birdcage coil decoupling device

110 combining unit

111 combiner

111a combiner input port

111b combiner output port

112 input end of combiner unit

Output terminal of 113 combining unit

114 first combiner

114a first input port

114b second input port

114c first output port

114d second output port

115 second combiner

115a third input port

115b fourth input port

115c third output port

115d fourth output port

116 third combiner

116a fifth input port

116b sixth input port

116c fifth output port

116d sixth output port

117 fourth combiner

117a seventh input port

117b eighth input port

117c seventh output port

117d eighth output port

118 the fifth circuit combiner

118a ninth input port

118b tenth input port

118c ninth output port

118d tenth output port

119 sixth combiner

119a eleventh input port

119b eleventh input port

119c twelfth output port

119d twelfth output port

200 birdcage coil

210 coil port

300 power supply

500 gradient module

600 magnet module

700 controller

800 upper computer

910 radio frequency circuit

920 radio frequency power amplifier

930A/D converter

Detailed Description

For the purpose of the present application, technical solutions and advantages thereof will be more clearly understood from the following detailed description of the birdcage coil decoupling apparatus 100, the birdcage coil decoupling system 10 and the magnetic resonance system 20 provided in the present application with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The present application provides a birdcage coil decoupling apparatus 100. The birdcage coil decoupling assembly 100 is used in conjunction with the birdcage coil 200. The birdcage coil decoupling device 100 is electrically connected to the birdcage coil 200 and the power supply 300, respectively. The birdcage coil 200 is not limited in its kind. The birdcage coil 200 can be one of a high-pass birdcage coil, a low-pass birdcage coil, and a band-pass birdcage coil. The birdcage coil 200 is used to transmit radio frequency pulses to generate a radio frequency magnetic field (i.e., the B1 field). The power supply 300 is used for supplying power to the birdcage coil decoupling device 100. In other words, the power supply 300 is configured to generate a power signal and transmit the power signal to the birdcage coil decoupling apparatus 100.

As shown in fig. 1 and 2, in an embodiment of the present application, the birdcage coil decoupling device 100 includes a combining unit 110. The combining unit 110 includes a plurality of combiners 111. The plurality of combiners 111 are connected in series end to form the combining unit 110. The input end 112 of the combining unit 110 is electrically connected to the power supply 300. The input end 112 of the combining unit 110 is configured to receive a power signal generated by the power supply 300. The output terminal 113 of the combining unit 110 is electrically connected to the birdcage coil 200. The output 113 of the combining unit 110 is configured to transmit and distribute the power signal to the plurality of coil ports 210 of the birdcage coil 200, so as to decouple the birdcage coil 200.

Specifically, the birdcage coil 200 is a multi-port birdcage coil. That is, the number of coil ports 210 of the birdcage coil 200 is greater than 2. A plurality of coil ports 210 are provided on the birdcage coil 200, the coil ports 210 also being referred to as feed ports. The plurality of coil ports 210 are disposed on a capacitor of the birdcage coil 200. Each of the capacitors is provided with one of the coil ports 210. By inputting power signals with phase differences to the coil ports 210, the birdcage coil 200 generates a circularly polarized rf magnetic field.

During the use of the birdcage coil decoupling device 100, the power supply 300 generates a power signal and inputs the power signal to the input end 112 of the combining unit 110. The power signals are subjected to phase shift and/or amplitude change by the plurality of combiners 111, and the power signals with phase difference and/or amplitude difference are output to different coil ports 210. By arranging the combining unit 110, the power signals between the plurality of coil ports 210 are prevented from being coupled during the whole transmission process of the power signals. In other words, the birdcage coil decoupling apparatus 100 achieves decoupling of the multi-port birdcage coil signal transmission process.

In this embodiment, the decoupling of the birdcage coil with the multiple coil ports 210 is realized by arranging the birdcage coil decoupling device 100 formed by connecting the plurality of combiners 111 in series end to end. In addition, each coil port 210 can independently control the phase and amplitude of the signal, resulting in a higher uniformity of the radio frequency magnetic field generated by the birdcage coil 200.

As shown in fig. 3, in an embodiment of the present application, each of the combiners 111 includes at least one combiner input port 111a and at least one combiner output port 111 b. A part of the at least one combiner input port 111a and the at least one combiner output port 111b is used for realizing connection between different combiners 111. Another part of the at least one combiner input port 111a and the at least one combiner output port 111b is configured to serve as the input end 112 of the combining unit 110 and the output end 113 of the combining unit 110.

Specifically, the number of the combiner input ports 111a of each of the combiners 111 may be plural. The combiner output port 111b may be plural. To avoid port waste, some of the plurality of combiner input ports 111a and the plurality of combiner output ports 111b are used for series connection between different ones of the combiners 111. Another part of the plurality of combiner input ports 111a and the plurality of combiner output ports 111b serves as an input terminal 112 of the combining unit 110 and an output terminal 113 of the combining unit 110, i.e., is used to be electrically connected to the birdcage coil 200 and the power supply 300, respectively.

In this embodiment, by reasonably allocating the purposes of the combiner input port 111a and the combiner output port 111b, while avoiding port waste, the connection between the combiners 111 is realized, and the connection between the combiners 111 and the birdcage coil 200 and the power supply 300 is also realized.

With continued reference to fig. 3, in an embodiment of the present application, each of the combiners 111 includes two combiner input ports 111a and two combiner output ports 111 b.

Specifically, two combiner input ports 111a may be provided at one end of the combiner 111. Two combiner output ports 111b may be disposed at the other end of the combiner 111.

In this embodiment, each combiner 111 includes two combiner input ports 111a and two combiner output ports 111b, so that the number of ports can be maximally utilized. The number of the ports is not excessive to cause waste, and the normal connection requirement of the components can be ensured.

Referring to fig. 3, in an embodiment of the present application, the number of the power supplies 300 is multiple. The sum of the number of the combiner input ports 111a of the plurality of combiners 111 is equal to twice the number of the power supply sources 300. The sum of the number of combiner output ports 111b of the plurality of combiners 111 is equal to twice the number of coil ports 210.

Specifically, in the present embodiment, there are a plurality of power supplies 300, and a plurality of coil ports 210. The sum of the number of the combiner input ports 111a is equal to twice the number of the power supplies 300, which can satisfy both the connection requirement of the power supplies 300 and the connection requirement between the combiners 111. Similarly, the sum of the number of the output ports 111b of the combiner is equal to twice the number of the coil ports 210, which can satisfy the connection requirement of the birdcage coil 200 and the connection requirement among the combiners 111.

In this embodiment, by setting the number sum of the combiner input ports 111a of the plurality of combiners 111 and the specific number of the number sum of the combiner input ports 111a of the plurality of combiners 111, the connection requirement between the birdcage coil 200 and the power supply 300 and the connection requirement between the plurality of combiners 111 can be satisfied.

Referring to fig. 3, in an embodiment of the present application, the number of the power supplies 300 is four. The number of the coil ports 210 is four. The combining unit 110 includes four of the combiners 111. Each of the combiners 111 includes two of the combiner input ports 111a and two of the combiner output ports 111 b.

Specifically, the birdcage coil decoupling device 100 in the present embodiment is applied to decoupling of a four-port birdcage coil. The four-port birdcage coil is provided with four coil ports 210. The four-port birdcage coil includes an upper end ring, a lower end ring, and metal legs connected between the upper end ring and the lower end ring. The arrangement of the four coil ports 210 in the four-port birdcage coil is not limited. Alternatively, as shown in fig. 4, four coil ports 210 may be disposed at equal intervals in the upper end ring of the four-port birdcage coil.

The number of combiners, the number of coil ports 210, and the number of power supplies 300 in this embodiment are equal to each other, and are four. Each of the combiners 111 includes two of the combiner input ports 111a and two of the combiner output ports 111 b. It is understood that the total number of the combiner input ports 111a is eight. The total number of the combiner output ports 111b is eight. The four combiner input ports 111a are used to connect to four power supplies 300, respectively. The four combiner output ports 111b are used for respectively connecting four coil ports 210 in the four-port birdcage coil. The remaining four of the combiner input ports 111a and four of the combiner output ports 111b are used for connection between four combiners 111. The number of the combiner input ports 111a and the combiner output ports 111b in this embodiment is reasonable, and the connection requirement between the four-port birdcage coil and the power supply 300 and the connection requirement between the plurality of combiners 111 can be met.

In this embodiment, the number of combiners, the number of coil ports 210, and the number of power supplies 300 are equal to each other, and are four, so that matching with the four-port birdcage coil is realized. The connection requirements of the four-port birdcage coil and the power supply 300 are met, and the connection requirements of the plurality of combiners 111 are also met. This embodiment birdcage line formula coil includes four input ports, and has 90 degrees, 180 degrees phase offsets between these four input ports, adopts the decoupling zero device 100 of birdcage coil to realize the decoupling zero between each coil port 210 among the four-port birdcage coil, avoids power signal's mutual interference.

As shown in fig. 5 and 6, in an embodiment of the present application, the combining unit 110 includes a first combiner 114, a second combiner 115, a third combiner 116, and a fourth combiner 117. The first combiner 114 includes a first input port 114a, a second input port 114b, a first output port 114c, and a second output port 114 d. The second combiner 115 includes a third input port 115a, a fourth input port 115b, a third output port 115c, and a fourth output port 115 d. The third combiner 116 includes a fifth input port 116a, a sixth input port 116b, a fifth output port 116c, and a sixth output port 116 d. The fourth combiner 117 includes a seventh input port 117a, an eighth input port 117b, a seventh output port 117c, and an eighth output port 117 d.

The first input port 114a, the second input port 114b, the fifth input port 116a, and the sixth input port 116b are electrically connected to one of the power supplies 300, respectively, and serve as the input end 112 of the combining unit 110.

The third output port 115c, the fourth output port 115d, the seventh output port 117c, and the eighth output port 117d are electrically connected to one coil port 210, respectively, and serve as the output terminal 113 of the combining unit 110.

The first output port 114c is electrically connected to the third input port 115a, the fourth input port 115b is electrically connected to the fifth output port 116c, the sixth output port 116d is electrically connected to the eighth input port 117b, and the seventh input port 117a is electrically connected to the second output port 114 d.

The above description is a specific connection relationship of the birdcage coil decoupling device 100 applied to the four-port birdcage coil. Theoretical analysis is performed below on the decoupling feasibility of the birdcage coil decoupling apparatus 100 applied to the four-port birdcage coil.

For a four-port birdcage coil without decoupling, a scattering parameter matrix is set to be S^a，S^aIs a four element array. The birdcage coil decoupling device 100 applied to the four-port birdcage coil (hereinafter, referred to as the birdcage coil decoupling device 100 in this embodiment and the four-port birdcage coil for short)The four coil ports 210 are connected respectively. The birdcage coil decoupling apparatus 100 in this embodiment can be considered to be coupled to the quad array. S^aThe matrix form of (a) is shown in equation 1.

The S parameter of the birdcage coil decoupling apparatus 100 in this embodiment can be expressed as formula 2.

[S]_8×8Equation 2

The scattering parameter of the birdcage coil decoupling apparatus 100 in this embodiment can be expressed as formula 3.

The scattering parameter of the birdcage coil decoupling apparatus 100 in this embodiment can also be expressed as formula 4.

Through the above formula, the scattering parameter matrix S of the birdcage coil decoupling device 100 and the array in the embodiment can be obtained^cAs shown in equation 5.

S^c＝S_mm+S_mn[(S^a)^-1-S_nn]^-1S_nm(m-1, 2,3,4. n-5, 6,7,8) formula 5

Suppose that

The mixed scattering parameter matrix S^cCan be expressed as equation 6.

Wherein λ isS^aThe eigenvalues of (a). Due to the structural symmetry of the birdcage coil 200, the contents of equation 7 can be obtained.

Further, λ is calculated by equation 8₁、λ₂、λ₃And λ₄。

Obtaining a matrix S by the formula^aThe conclusion of diagonalization is that the four input ports of the birdcage coil decoupling device 100 in the present embodiment, which are connected to the power supply 300, can be decoupled. In other words, it is concluded that decoupling can be achieved between the first input port 114a, the second input port 114b, the fifth input port 116a and the sixth input port 116 b.

Further, S_mn＝[e₁ e₂ e₃ e₄]Where e is the scattering parameter matrix S^aOrthogonal to the principal vector. Setting the orthogonal evidence vector as:

to sum up, if the first input port 114a, the second input port 114b, the fifth input port 116a and the sixth input port 116b are decoupled, the scattering parameter matrix needs to satisfy the condition of formula 10.

Thus, equation 11 is obtained.

In summary, it is proved that four-port birdcage coil decoupling is feasible, and the first combiner 114, the second combiner 115, the third combiner 116, and the fourth combiner 117 need to satisfy equation 11 after combination.

According to the embodiment, decoupling between the coil ports 210 in the four-port birdcage coil is realized, and mutual interference of power signals is avoided.

In an embodiment of the present application, the combiner 111 is a same-frequency combiner.

Specifically, the combiner 111 may be a same-frequency combiner. The same-frequency combiner is also called a 3dB bridge, and the structure of the same-frequency combiner is shown in FIG. 7. As shown in fig. 7, the on-frequency combiner includes an a port, a b port, a c port, and a d port. The a port and the d port are input ports. The b port and the c port are output ports. The power signal inputted from the a port is equally distributed to the b port and the c port. b port c port has a 90 degree phase offset between them. And the power signal input from the a-port is not coupled to the d-port. Similarly, the power signal inputted from the d port is equally distributed to the b port and the c port. And the power signal input from the d-port is not coupled to the a-port. The port a and the port d can transmit power signals simultaneously, and the power signals obtained from the port b and the port c are the superposition of two sections of power signals.

Based on the embodiment of the birdcage decoupling device of the four-port birdcage coil, the S matrix of the same-frequency combiner just meets the decoupling requirement of the four-port birdcage coil as formula 12.

In this embodiment, through setting up combiner 111 is the same frequency combiner, through the combination of a plurality of same frequency combiners, can satisfy the demand of multiport birdcage coil decoupling.

Except four port birdcage coils, this application provides birdcage coil decoupling zero device can also be applied to the multiport birdcage coil of arbitrary coil port quantity.

In an optional embodiment, a matching circuit may be further disposed between the first combiner 114, the second combiner 115, the third combiner 116, and the fourth combiner 117 and the power supply 300. The matching circuit enables the power signal generated by the power supply 300 to flow in one direction. Namely: the matching circuit prevents the power signal generated by the power supply 300 from being reused. In this embodiment, a first matching circuit may be disposed between the first combiner 114 and the power supply 300. A second matching circuit may be disposed between the second combiner 115 and the power supply 300. A third matching circuit may be provided between the third combiner 116 and the power supply 300. A fourth matching circuit may be disposed between the fourth combiner 117 and the power supply 300. Of course, in other embodiments, the power supplies corresponding to the first combiner 114, the second combiner 115, the third combiner 116, and the fourth combiner 117 may be independent from each other.

Fig. 8 is a schematic structural diagram of a birdcage coil decoupling apparatus 100 applied to a three-port birdcage coil according to an embodiment of the present application.

In an embodiment of the present application, as shown in fig. 8, the birdcage coil decoupling apparatus 100 applied to the three-port birdcage coil includes two combiners 111: a fifth hybrid 118 and a sixth hybrid 119. The fifth combiner 118 includes a ninth input port 118a, a tenth input port 118b, a ninth output port 118c, and a tenth output port 118 d. The sixth combiner 119 comprises an eleventh input port 119a, a twelfth input port 119b, an eleventh output port 119c and a twelfth output port 119 d.

The ninth input port 118a, the tenth input port 118b and the twelfth input port 119b are electrically connected to one of the power supplies 300, respectively, and serve as the input terminal 112 of the combining unit 110.

The ninth output port 118c, the eleventh output port 119c, and the twelfth output port 119d are electrically connected to one of the coil ports 210, respectively, and serve as the output end 113 of the combining unit 110.

The tenth output port 118d is electrically connected to the eleventh input port 119 a.

According to the embodiment, decoupling among the coil ports 210 in the three-port birdcage coil is realized, and mutual interference of power signals is avoided.

The present application further provides a birdcage coil decoupling system 10.

As shown in fig. 9 and 10, in an embodiment of the present application, the birdcage coil decoupling system 10 includes a power supply 300, a birdcage coil decoupling device 100, and a birdcage coil 200. The input end of the birdcage coil decoupling device 100 is electrically connected to the power supply 300. The output of the birdcage coil decoupling apparatus 100 is electrically connected to the plurality of coil ports 210 of the birdcage coil 200. The power supply 300 is configured to generate a power signal. The birdcage decoupling assembly is configured to receive a power signal generated by the power supply 300. The birdcage decoupling apparatus is further configured to transmit and distribute the power signal to a plurality of coil ports 210 of the birdcage coil 200 to enable decoupling of the birdcage coil 200.

Fig. 9 is a schematic structural diagram of the birdcage coil decoupling system 10. Fig. 10 is a signal transmission diagram of the birdcage coil decoupling system 10.

In this embodiment, the decoupling of the multi-coil port 210 birdcage coil is realized by providing the birdcage coil structure system composed of the power supply 300, the birdcage coil 200, and the birdcage coil decoupling device 100. In addition, each coil port 210 can independently control the phase and amplitude of the signal, resulting in a higher uniformity of the radio frequency magnetic field generated by the birdcage coil 200.

The present application also provides a magnetic resonance system 20 based on a birdcage coil structure.

As shown in fig. 11, in an embodiment of the present application, the magnetic resonance system 20 based on the birdcage coil structure includes a radio frequency module, a gradient module 500, a magnet module 600, the birdcage coil decoupling device 100 as mentioned in the foregoing, a power supply 300, a controller 700, and an upper computer 800.

The radio frequency module includes a birdcage coil 200. The birdcage coil 200 is used to generate radio frequency magnetic fields. The gradient module 500 includes gradient coils 510. The gradient coil 510 is sleeved outside the birdcage coil 200. The gradient coils 510 are used to generate gradient magnetic fields. The magnet module 600 is sleeved outside the gradient coil 510. The magnet module 600 is used to generate a main magnetic field. The birdcage coil decoupling apparatus 100 is electrically connected to the birdcage coil 200. The birdcage coil decoupling apparatus 100 is configured to perform a decoupling operation on the birdcage coil 200. The power supply 300 is electrically connected to the birdcage coil decoupling device 100. The power supply 300 is configured to generate a power signal and transmit the power signal to the birdcage coil decoupling apparatus 100. The controller 700 is electrically connected to the birdcage coil decoupling apparatus 100 and/or the gradient module 500. The controller 700 is configured to control the radio frequency module to generate the radio frequency magnetic field and/or the gradient module 500 to generate the gradient magnetic field. The upper computer 800 is in communication connection with the controller 700. The upper computer 800 is configured to transmit a scan sequence instruction to the controller 700 to control the operation of the magnetic resonance system and generate a magnetic resonance image.

With continuing reference to figure 11, in one embodiment of the present application, the birdcage coil configuration based magnetic resonance system 20 further includes auxiliary circuitry. The ancillary circuits include a radio frequency circuit 910, a radio frequency power amplifier 920, and an analog-to-digital converter 930. The radio frequency circuit 910 is electrically connected to the birdcage coil decoupling apparatus 100. One end of the rf power amplifier 920 is electrically connected to the rf circuit 910. The other end of the rf power amplifier 920 is electrically connected to the controller 700. One end of the analog-to-digital converter 930 is electrically connected to the birdcage coil decoupling device 100. The other end of the analog-to-digital converter 930 is electrically connected to the controller 700.

In particular, the magnet module 600 is used to generate a main magnetic field. The gradient module 500 includes a gradient coil 510 and a gradient current amplifier 520 (AMP). The gradient coil 510 includes gradient coils in the x, y, and z directions. The rf module further includes an rf transmitting module and an rf receiving module (not shown). The controller 700 may be a spectrometer module. The spectrometer module includes one or more of a pulse sequencer, a gradient waveform generator, a transmitter and a receiver (not shown in the figures). The upper computer 800 may be a computer module. The computer module is used for controlling the operation of the magnetic resonance system and the final magnetic resonance imaging.

The magnetic resonance imaging process comprises the following steps:

s100, the computer module stores and sends a scan sequence instruction to be executed to the spectrometer module.

And S200, the pulse sequence generator in the spectrometer module controls the gradient waveform generator and the transmitter according to the scanning sequence instruction, and the gradient waveform generator outputs a gradient pulse signal with a preset time sequence and waveform.

S300, the gradient pulse signals pass through the gradient current amplifiers 520 in the Gx, Gy, and Gz directions, and then pass through three independent channels Gx, Gy, and Gz in the gradient module 500, each gradient current amplifier excites a corresponding one of the gradient coils 510 in the gradient coil set to generate a gradient magnetic field for generating a corresponding spatial encoding signal, so as to spatially localize the magnetic resonance signals.

S400, the pulse sequence generator in the spectrometer module further executes a scanning sequence and outputs data including timing, strength, shape and the like of radio frequency transmitted radio frequency pulses, timing of radio frequency reception and the length of a data acquisition window to the transmitter.

S500, the transmitter transmits the radio frequency pulse to the birdcage coil 200 in the radio frequency module to generate a B1 field (i.e., the radio frequency magnetic field).

S600, after the signals emitted by the excited atomic nuclei in the patient are decoupled by the birdcage coil decoupling device 100 under the action of the B1 field, the signals are sensed by the receiving coil in the radio frequency module and transmitted to the radio frequency power amplifier 920 through the transmitting/receiving switch for amplification.

S700, the amplified magnetic resonance signal is subjected to one or more of demodulation, filtering and AD conversion by the analog-to-digital converter 930, and then transmitted to the memory module of the computer module. And when the storage module acquires a group of original k-space data, finishing scanning.

In this embodiment, the decoupling of the birdcage coil with the multiple coil ports 210 is realized by providing the magnetic resonance system with the birdcage coil decoupling device 100, so that the whole magnetic resonance system operates normally. In addition, as the number of the feed ports of the birdcage coil 200 increases, the number of the power amplifiers in the power supply 300 also increases accordingly, thereby reducing the maximum output power of every other power amplifier and relieving the load stress on the power amplifiers.

In addition, the birdcage coil decoupling system 10 is not limited to be used in a magnetic resonance system, but can also be used in a medical device or medical system related to magnetic resonance, such as a large functional metabolic and molecular imaging diagnosis device (PET/MR system) formed by integrally combining two aspects of electron emission computed tomography (PET) and magnetic resonance imaging (MR), or a magnetic resonance radiotherapy system (MR/RT system).

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-described embodiments are intended to be merely illustrative of the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A birdcage coil decoupling assembly (100) for use with a birdcage coil (200), the birdcage coil decoupling assembly (100) being electrically connected to the birdcage coil (200) and a power supply (300), respectively, the birdcage coil decoupling assembly (100) comprising:

the combiner unit (110), the combiner unit (110) comprises a plurality of combiners (111), and the combiners (111) are connected in series end to form the combiner unit (110);

the input end (112) of the combining unit (110) is electrically connected with the power supply (300) and is used for receiving a power signal generated by the power supply (300);

an output terminal (113) of the combining unit (110) is electrically connected to the birdcage coil (200) and is configured to transmit and distribute the power signal to a plurality of coil ports (210) of the birdcage coil (200) to decouple the birdcage coil (200).

2. The birdcage coil decoupling device according to claim 1, wherein each of the combiners (111) includes at least one combiner input port (111a) and at least one combiner output port (111 b); a part of the at least one combiner input port (111a) and the at least one combiner output port (111b) is used for realizing connection between different combiners (111), and the other part of the ports is used as an input end (112) of the combining unit (110) and an output end (113) of the combining unit (110).

3. The birdcage coil decoupling device (100) according to claim 2,

each of the combiners (111) includes two of the combiner input ports (111a) and two of the combiner output ports (111 b).

4. The birdcage coil decoupling device (100) according to claim 3, wherein the power supply (300) is a plurality, a sum of a number of combiner input ports (111a) of the plurality of combiners (111) is equal to twice a number of the power supply (300), and a sum of a number of combiner output ports (111b) of the plurality of combiners (111) is equal to twice a number of the coil ports (210).

5. The birdcage coil decoupling device (100) according to claim 4, wherein the power supply (300) is four in number, the coil ports (210) are four in number, the combining unit (110) includes four of the combiners (111), and each of the combiners (111) includes two of the combiner input ports (111a) and two of the combiner output ports (111 b).

6. The birdcage coil decoupling device (100) according to claim 5, characterized in that the combining unit (110) includes:

a first combiner (114) comprising a first input port (114a), a second input port (114b), a first output port (114c), and a second output port (114 d);

a second combiner (115) comprising a third input port (115a), a fourth input port (115b), a third output port (115c), and a fourth output port (115 d);

a third combiner (116) comprising a fifth input port (116a), a sixth input port (116b), a fifth output port (116c) and a sixth output port (116 d); and

a fourth combiner (117) including a seventh input port (117a), an eighth input port (117b), a seventh output port (117c), and an eighth output port (117 d);

the first input port (114a), the second input port (114b), the fifth input port (116a) and the sixth input port (116b) are electrically connected with one power supply (300) respectively and used as input ends (112) of the combining unit (110);

the third output port (115c), the fourth output port (115d), the seventh output port (117c), and the eighth output port (117d) are electrically connected to one coil port (210), respectively, and serve as output ports (113) of the combining unit (110);

the first output port (114c) is electrically connected to the third input port (115a), the fourth input port (115b) is electrically connected to the fifth output port (116c), the sixth output port (116d) is electrically connected to the eighth input port (117b), and the seventh input port (117a) is electrically connected to the second output port (114 d).

7. The birdcage coil decoupling device (100) according to one of claims 1 to 6, characterized in that the combiner (111) is an intra-frequency combiner.

8. A birdcage coil decoupling system (10), comprising:

a power supply (300) for generating a power signal;

the birdcage coil decoupling device (100) of any one of claims 1 to 7, an input of the birdcage coil decoupling device (100) being electrically connected to the power supply (300) for receiving a power signal generated by the power supply (300);

a birdcage coil (200) having a plurality of coil ports (210), the birdcage coil (200) being electrically connected to the output of the birdcage coil decoupling device (100) through the plurality of coil ports (210);

the birdcage coil decoupling apparatus (100) is further configured to transmit and distribute the power signal to a plurality of coil ports (210) of the birdcage coil (200) to enable decoupling of the birdcage coil (200).

9. A birdcage coil structure-based magnetic resonance system (20), comprising:

a radio frequency module comprising a birdcage coil (200); the birdcage coil (200) is used for generating a radio frequency magnetic field;

a gradient module (500) comprising a gradient coil (510); the gradient coil (510) is sleeved outside the birdcage coil (200), and the gradient coil (510) is used for generating a gradient magnetic field;

a magnet module (600) sleeved outside the gradient coil (510) and used for generating a main magnetic field;

the birdcage coil decoupling device (100) of any one of claims 1 to 7, electrically connected with the birdcage coil (200) for performing a decoupling operation on the birdcage coil (200);

a power supply (300) electrically connected to the birdcage coil decoupling device (100) for generating a power signal and transmitting the power signal to the birdcage coil decoupling device (100);

a controller (700) electrically connected to the birdcage coil decoupling device (100) and/or the gradient module (500) for controlling the radio frequency module to generate the radio frequency magnetic field and/or the gradient module (500) to generate the gradient magnetic field; and

and the upper computer (800) is in communication connection with the controller (700) and is used for transmitting scanning sequence instructions to the controller (700) so as to control the magnetic resonance system to operate and generate magnetic resonance images.

10. The birdcage coil structure-based magnetic resonance system (20) according to claim 9, further comprising an auxiliary circuit;

the auxiliary circuit includes:

a radio frequency circuit (910) electrically connected to the birdcage coil decoupling device (100);

a radio frequency power amplifier (920), one end of which is electrically connected with the radio frequency circuit (910), and the other end of which is electrically connected with the controller (700); and

and one end of the analog-to-digital converter (930) is electrically connected with the birdcage coil decoupling device (100), and the other end of the analog-to-digital converter is electrically connected with the controller (700).