CN108241134A - A Gradient Coil Using Composite Cooling Water Tubes - Google Patents

Abstract

The invention discloses a kind of gradient coils using composite material cooling water pipe, including gradient coil main body, the coil main body is from inside to outside successively by radio shielding layer, primary coil portion, water main, shimming space, shield water pipe and shielded coil part composition, the primary coil portion is from inside to outside respectively by x-ray circle, Y coils, Z-line ring layer is stacked, the shielded coil part is from inside to outside respectively by Z shielded coils, composition is laminated in X shielded coils and Y shielded coils, this structure has taken into account X, Y, the balancing performance of Z-line circle, composite material water pipe is used, improve the capacity of heat transmission of cooling system, wherein shimming is spatially located among water-cooling system, it ensure that the stability of shimming material temperature, so as to ensure that magnetic field's regularity.

Description

A Gradient Coil Using Composite Cooling Water Tubes

Technical field:

The invention belongs to the technical field of MRI gradient coils, in particular to a gradient coil using composite cooling water pipes.

Background technique:

The gradient coil is one of the core components of the MRI (Magnetic Resonance Imaging, English full name: Magnetic Resonance Imaging) system, which mainly realizes frequency encoding, phase encoding and layer selection during the MRI scanning process.

The existing traditional gradient coil structure uses the hollow Z main coil and Z shielding coil as the cooling channel. In order to reduce the influence of eddy current, the diameter of the coil should not be too large, which will affect the heat dissipation effect. If different connection methods are used to meet the heat dissipation requirements , will form too many joints, increasing the probability of water leakage. At the same time, the biggest problem of this coil is that it cannot realize the separation of water and electricity. To ensure the safety of patients, deionized water must be used, which increases the difficulty and cost of maintenance. The patent is ZL201420289868.3 "An Active Shielding Gradient Coil Structure". The structure proposed in this patent improves the heat dissipation capability of the gradient coil by sacrificing the performance of a part of the Z coil. However, this design does not consider many technological difficulties in the manufacturing process. Consider the user's requirements for radio frequency shielding and shimming space, as well as the impact of the coil based on this structure on the uniformity of the magnetic field.

Invention content:

In view of the above problems, the technical problem to be solved by the present invention is to provide a gradient coil using a composite cooling water pipe.

A gradient coil using a composite material cooling water pipe according to the present invention includes a gradient coil main body, and the coil main body is sequentially composed of a radio frequency shielding layer, a main coil part, a main water pipe, a shimming space, a shielding water pipe and a shielding coil part from inside to outside , the main coil part is composed of X coils, Y coils, and Z coils from the inside to the outside, and the shielding coils are respectively composed of Z shielding coils, X shielding coils and Y shielding coils from the inside to the outside. It includes a first X coil, a first corresponding X shielding coil, a second X coil and a second corresponding X shielding coil, the first X coil is connected to the first corresponding X shielding coil through a first joint, and the second X coil It is connected with the second corresponding X shielding coil through the second joint, the first corresponding X shielding coil and the second corresponding X shielding coil are connected through the third joint, and the Y coil is assembled in the direction orthogonal to the X coil , the Y coil includes a first Y coil, a first corresponding Y shielding coil, a second Y coil and a second corresponding Y shielding coil, the connection mode of the Y coil is the same as that of the X coil, one end of the Z coil and one end of the shielding coil part The fourth joint is connected, and the currents of the corresponding parts of the Z coil and the shielding coil are opposite. The innermost layer of the main body of the gradient coil is also provided with a layer of stainless steel mesh.

Preferably, both the main water pipe and the shielded water pipe are cooling water pipes made of composite materials.

Preferably, the main water pipe and the shielded water pipe may be composed of multiple parallel composite cooling water pipes.

Beneficial effects of the present invention: 1. A gradient coil using a composite material cooling water pipe according to the present invention, the coil uses a composite material cooling water pipe, which ensures the heat conduction capacity of the cooling system, wherein the main coil water pipe is twice as large as the shielding coil part, ensuring that the main water pipe has the same effect on the main coil part Sufficient heat dissipation capacity, the water pipe has no joints inside the gradient coil, reducing the risk of water leakage.

2. A gradient coil using a composite material cooling water pipe of the present invention, the coil structure is a radio frequency shielding layer, a main coil part, a main water pipe, a shimming part, a shielding water pipe and a shielding coil part from the inside to the outside, wherein the main coil part The sequence is X, Y, Z, and the order of the shielding coil is Z, X, Y. This structure takes into account the performance balance of the X, Y, and Z coils. At the same time, the cooling water pipes are located on both sides of the shimming part, ensuring Temperature stability, thus ensuring the uniformity of the magnetic field.

Description of drawings:

For ease of illustration, the present invention is described in detail by the following specific implementations and accompanying drawings.

Fig. 1 is a schematic structural diagram of a gradient coil cooled by a Z coil in traditional use.

Fig. 2 is a schematic diagram of the structure of the gradient coil most similar to the present application.

Fig. 3 is a schematic diagram of the structure of the gradient coil of the present invention.

Figure 4 is a schematic diagram of the connection of the X and Y coils.

Figure 5 is a schematic diagram of the connection of the Z coil.

Fig. 6 is a sectional view of the gradient coil along the longitudinal direction;

Fig. 7 is a design result diagram of two gradient coils based on the present invention.

In the figure: 1. RF shielding layer; 2. X coil; 21. First X coil; 22. Second X coil; 3. Y coil; 4. Z coil; 5. Main water pipe; 6. Shimming space; 7 , shielding water pipe; 8, Z shielding coil; 9, X shielding coil; 91, the first corresponding X shielding coil; 92, the second corresponding X shielding coil; 10, Y shielding coil; 11, imaging area; 12, the first connector ; 13, the second joint; 14, the third joint; 15, the fourth joint.

Detailed ways:

In order to make the object, technical solution and advantages of the present invention clearer, the present invention is described below through specific embodiments shown in the accompanying drawings. It should be understood, however, that these descriptions are exemplary only and are not intended to limit the scope of the present invention. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concept of the present invention.

As shown in Figures 1-7, a gradient coil using a composite material cooling water pipe in this embodiment includes a gradient coil body, the structure of the upper half of the axial section of the gradient coil body is shown in Figure 3, and the lower half and its axis Symmetrically, the coil main body is composed of radio frequency shielding layer 1, main coil part, main water pipe 5, shimming space 6, shielded water pipe 7 and shielding coil part from inside to outside, and the main coil part is composed of X Coil 2, Y coil 3, and Z coil 4 are stacked. The shielding coil part is composed of Z shielding coil 8, X shielding coil 9 and Y shielding coil 10 from inside to outside. Both X coil 2 and Y coil 3 are composed of two One main coil and two shielding coils, as shown in Figure 4, the X coil 2 includes a first X coil 21, a first corresponding X shielding coil 91, a second X coil 22 and a second corresponding X shielding coil 92, The first X coil 21 is connected to the first corresponding X shielding coil 91 through the first connector 12, the second X coil 22 is connected to the second corresponding X shielding coil 92 through the second connector 13, and the first corresponding X The shielding coil 21 and the second corresponding X shielding coil 22 are connected through the third joint 14 to form a complete X coil 2. Through this connection, the current direction of the main coil part and the corresponding shielding coil part are guaranteed to be opposite, and the magnetic field is realized. Shielding effect, reducing eddy current, the Y coil 3 is assembled in the direction orthogonal to the X coil 2, and the Y coil 3 includes a first Y coil, a first corresponding Y shielding coil, a second Y coil and a second corresponding Y Shielding coil, Y coil 3 is connected in the same way as X coil 2, and Z coil 4 and shielding coil part are wound, as shown in Figure 5, one end of the Z coil 4 and one end of the shielding coil part are connected through the fourth joint 15 connected, and the currents of the corresponding parts of the Z coil 4 and the shielding coil are opposite, and the innermost layer of the gradient coil body is also provided with a layer of stainless steel mesh to shield the radio frequency signal and prevent the gradient signal from interfering with radio frequency reception. Since the structure of the gradient coil involved in this invention fully considers the gradient performance, cooling capacity, stability of the magnetic field and user needs of the gradient coil, and the temperature of the gradient coil is controlled below 45 degrees Celsius when working at full power, which fully meets the system requirements. .

Specifically, the main water pipe 5 and the shielded water pipe 7 are both composite material cooling water pipes, which provide sufficient heat conduction capacity for the gradient coil to dissipate heat. The main water pipe 5 and the shielded water pipe 7 can adopt multiple composite material water pipes, and use a parallel connection mechanism, so that the entire coil has only one water inlet and one water outlet, which is convenient for users to apply. The gradient coil of the present invention uses a composite material water pipe and improves the heat conduction capacity of the cooling system, wherein the shimming space 6 is located in the middle of the water cooling system, which ensures the stability of the temperature of the shimming material, thereby ensuring that the ellipsoidal imaging area 11 The homogeneity of the magnetic field. The use of composite materials meets the needs of gradient coils for heat conduction, and fully realizes the separation of water and electricity in gradient coils. Ordinary pure water or distilled water can be used as a refrigerant instead of deionized water, which reduces the dependence of end users on special materials. And reduce maintenance costs. The shimming space is located between the two water pipe layers, which ensures the stability of the temperature of the shimming iron sheet, thereby ensuring the uniformity of the magnetic field in the imaging area.

Figure 7 shows the design results of two gradient coils based on this structure. A is a high-field gradient coil, and B is a fast gradient coil. These two gradient coils have been verified by actual imaging in different system manufacturers. During the design process of the gradient coil, the required gradient performance and the influence of the realization process and gradient on the system should be fully considered. At the same time, special attention should be paid to the matching magnetic field environment and the structure and performance of the magnet.

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments. What are described in the above-mentioned embodiments and the description only illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have Variations and improvements are possible, which fall within the scope of the claimed invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (3)

1. a kind of gradient coil using composite material cooling water pipe, it is characterised in that：Including gradient coil main body, the coil Main body is from inside to outside successively by radio shielding layer, primary coil portion, water main, shimming space, shielding water pipe and shielded coil portion It is grouped as, the primary coil portion is stacked from inside to outside by x-ray circle, Y coils, Z-line ring layer respectively, the shielded coil part From inside to outside respectively by Z shielded coils, X shielded coils and Y shielded coils stacking form, the x-ray circle include the first x-ray circle, First corresponds to X shielded coils, the second x-ray circle and second corresponds to X shielded coils, the first x-ray circle X shielding lines corresponding with first Circle is connected by the first connector, and the second x-ray circle X shielded coils corresponding with second are connected by the second connector, and described first It is connected between corresponding X shielded coils and the second correspondence X shielded coils by third connector, the Y coils are assemblied in x-ray circle just On the direction of friendship, the Y coils include the first Y coils, the first correspondence Y shielded coils, the 2nd Y coils and second and correspond to Y shieldings Coil, Y coils connection mode is identical with x-ray circle, and one end of described Z-line circle one end and shielded coil part passes through the 4th connector phase Connection, and the electric current of Z-line circle and shielded coil part corresponding part is on the contrary, the gradient coil main body innermost layer is additionally provided with one layer Stainless (steel) wire.

2. a kind of gradient coil using composite material cooling water pipe according to claim 1, it is characterised in that：The master Water pipe and shielding water pipe are composite material cooling water pipe.

3. a kind of gradient coil using composite material cooling water pipe according to claim 1, it is characterised in that：The master Water pipe can be connected by more composite material cooling water pipes in parallel with shielding water pipe and be formed.