Gradient coil cooling and supporting device and permanent magnet type magnetic resonance system

Abstract

The invention discloses a gradient coil cooling and supporting device and a permanent magnet type magnetic resonance system, and relates to the technical field of magnetic resonance imaging, the gradient coil cooling and supporting device comprises a supporting heat dissipation layer, and a first cooling channel is arranged in the supporting heat dissipation layer; a gradient coil and a protruding structure are fixedly arranged on the inner wall or the outer wall of the supporting heat dissipation layer, the protruding structure is matched with a gap of the gradient coil in an embedded mode, and a second cooling channel communicated with the first cooling channel is formed in the protruding structure. The permanent magnet type magnetic resonance system comprises a main magnet, a cooling supporting device and a radio frequency coil which are sequentially arranged from outside to inside, and the radio frequency coil surrounds to form a detection space. According to the gradient coil, the inner wall or the outer wall of the supporting heat dissipation layer is provided with the protruding structure which is matched with the gap of the gradient coil in an embedded mode, the first cooling channel and the second cooling channel which are used for circulation of the cooling medium are arranged in the supporting heat dissipation layer and the protruding structure, a cooling structure and a supporting structure are combined into a whole, and the overall size of the coil is optimized.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic resonance imaging, and in particular to a gradient coil cooling support device and a permanent magnet type magnetic resonance system. Background Art

[0002] The permanent magnet type magnetic resonance system does not have the ultra-low constant temperature environment of superconducting materials. During operation, the components of the system will generate significant heat accumulation and conduction, resulting in uneven temperature. The magnetic resonance system relies on the stable main magnetic field generated by the permanent magnet, but the change of local temperature will seriously affect the uniformity of the magnetic field generated by the permanent magnet. The gradient coil is one of the main heat sources, and its heat is passively conducted to the permanent magnet, which is the main reason for the uneven temperature.

[0003] In addition, the aperture design of the magnetic resonance system detection space has a significant impact on the magnetic field performance. The aperture design of the magnetic resonance system refers to the effective inner diameter of the magnet in the magnetic resonance device, that is, the effective inner diameter of the cylindrical detection space after the shim coil, gradient coil, radio frequency coil and inner guard plate are installed. Under the condition of meeting the performance, optimizing the coil size to achieve a thinner structure becomes a key challenge. The support structure of traditional gradient coils is mostly glued or mechanically fixed, and the cooling system generally uses bulky cooling pipes, which not only leads to the thickening of the cooling layer and the increase of the overall weight of the system, but also has an adverse effect on the system performance due to the large area of ​​the magnetic resonance system aperture being occupied.

[0004] Therefore, there is an urgent need to develop a new cooling and supporting device for the gradient coil. Summary of the invention

[0005] The purpose of the present invention is to provide a gradient coil cooling support device and a permanent magnet type magnetic resonance system to solve the problems existing in the above-mentioned prior art. While satisfying the uniform cooling and effective support of the gradient coil, the coil size is optimized to achieve a thinner structure to reduce the occupied area of ​​the magnetic resonance system aperture.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A gradient coil cooling support device comprises a support heat dissipation layer, wherein a first cooling channel is arranged inside the support heat dissipation layer; a gradient coil and a protrusion structure are fixedly arranged on the inner wall or the outer wall of the support heat dissipation layer, wherein the protrusion structure is inlaid and matched with the gap of the gradient coil, and a second cooling channel connected to the first cooling channel is arranged inside the protrusion structure.

[0008] In an exemplary embodiment, the number of the first cooling channels inside the supporting heat dissipation layer is n, where n is an integer ≥ 1 or 2, and the plurality of first cooling channels are evenly arranged along the width direction or the length direction of the supporting heat dissipation layer.

[0009] In an exemplary embodiment, the second cooling channel is communicated with the adjacent first cooling channel.

[0010] In an exemplary embodiment, the thickness of the supporting heat dissipation layer is 0.3 mm to 1.5 mm.

[0011] In an exemplary embodiment, the material of the supporting heat dissipation layer is one or more of silicon, copper, carbon fiber, fiberglass, and non-magnetic steel.

[0012] In an exemplary embodiment, the supporting heat dissipation layer further includes a liquid supply channel and a liquid outlet channel, and one end of the first cooling channel is connected to the liquid supply channel, and the other end is connected to the liquid outlet channel.

[0013] In an exemplary embodiment, the liquid supply channel and the liquid outlet channel are respectively disposed at two ends of the supporting heat dissipation layer.

[0014] The present invention also provides a permanent magnet type magnetic resonance system, comprising the above-mentioned gradient coil cooling support device.

[0015] In an exemplary embodiment, the main magnet, the cooling support device and the radio frequency coil are sequentially arranged from the outside to the inside, and the radio frequency coil surrounds to form a detection space.

[0016] In an exemplary embodiment, the gradient coil includes an X-direction gradient coil, a Y-direction gradient coil, and a Z-direction gradient coil. The number of the supporting heat dissipation layers is multiple layers, and an X-direction gradient coil, a Y-direction gradient coil, or a Z-direction gradient coil is fixedly arranged on the inner wall or outer wall of each supporting heat dissipation layer.

[0017] Compared with the prior art, the present invention has achieved the following technical effects:

[0018] By providing a protruding structure on the inner wall or outer wall of the support heat dissipation layer that is inlaid with the gap of the gradient coil, when the gradient coil is installed on the inner wall or outer wall of the support heat dissipation layer, the single-layer support heat dissipation layer wraps the gradient coil on three sides, and when multiple layers of support heat dissipation layers with gradient coils installed are installed together from the inside to the outside, the other side of the gradient coil that is not wrapped fits with the next layer of support heat dissipation layer, and the support heat dissipation layer and the protruding structure are provided with a first cooling channel and a second cooling channel for circulating cooling medium, which can form effective and uniform heat dissipation and cooling for the gradient coil from all directions. In this way, the support heat dissipation layer realizes the supporting function for the gradient coil, and a cooling channel is provided inside it for heat dissipation and cooling of the gradient coil, combining the cooling structure and the support structure into one, optimizing the overall size of the coil, greatly reducing the space occupied by the magnet in the magnetic resonance system, and increasing the effective inner diameter of the magnetic resonance system.

[0019] Compared with the prior art, other technical solutions disclosed in the present invention also achieve the following technical effects:

[0020] By using silicon, XX, YY or ZZ as the material for the support heat dissipation layer, the thickness of the support heat dissipation layer can be reduced to 1.5 mm. When the entire magnetic resonance imaging system is used with more leeway, the negative impact of uneven permanent magnet temperature can be fully reduced, and the performance and stability of the system can be improved. In addition, silicon, XX, YY and ZZ have extremely low eddy current effects and have excellent performance in heat dissipation performance and structural hardness. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a cross-sectional schematic diagram of a permanent magnet type magnetic resonance imaging system involved in the present invention and a position schematic diagram of a gradient coil cooling support device disclosed in an embodiment of the present invention;

[0023] Figure 2 It is a structural schematic diagram of a gradient coil cooling support device disclosed in one embodiment of the present invention;

[0024] Figure 3 for Figure 2 The main view;

[0025] Figure 4 for Figure 2 Enlarged view of part A in the middle;

[0026] Figure 5 for Figure 3 Middle BB section view;

[0027] Figure 6 for Figure 5 Enlarged view of the middle C part;

[0028] Figure 7 It is a structural schematic diagram of a liquid supply ring / liquid outlet ring disclosed in an embodiment of the present invention;

[0029] Figure 8 for Figure 7 Enlarged view of the middle D part;

[0030] Fig. 9 for Figure 7 A magnified view of the middle D section from another angle;

[0031] Among them, 1. support heat dissipation layer; 2. gradient coil; 3. first cooling channel; 4. circular hole; 5. gap; 6. protrusion structure; 7. second cooling channel; 8. liquid supply ring; 9. liquid supply port; 10. liquid supply tank; 11. main magnet; 12. support heat dissipation layer z; 13. gradient coil A; 14. support heat dissipation layer a; 15. gradient coil B; 16. support heat dissipation layer b; 17. gradient coil C; 18. support heat dissipation layer c; 19. insulation layer; 20. radio frequency coil; 21. detection space. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. People familiar with the technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that the structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions that the present invention can be implemented, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present invention. In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. Therefore, the features defined as "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0034] It should also be noted that in the embodiments of the present application, the same figure mark is used to represent the same component or the same part.

[0035] The principle of magnetic resonance imaging (MRI) is to use the resonance phenomenon of specific atomic nuclei in an external static magnetic field for imaging. When these atomic nuclei are excited by a radio frequency pulse magnetic field with the same frequency as their precession, resonance will occur and electromagnetic signals will be emitted. Different tissues and lesions have different relaxation times, and the reverse induced voltage of the radio frequency receiving coil captures the magnetic resonance signal. In order to distinguish the source of spatial signals to achieve magnetic resonance imaging, it is necessary to add additional linear gradient magnetic fields to reproduce the position and thus obtain images.

[0036] Please refer to Figure 1 The permanent magnet type magnetic resonance imaging device relies on a permanent magnet (also called the main magnet 11) to form a permanent magnetic field. The permanent magnet is usually an annular cylindrical structure. Similar to this structure, the RF coil 20 and the gradient coil 2 are both annular cylindrical structures, and each part is basically coaxial. In terms of spatial distribution, the RF coil 20 is in the innermost layer, the gradient coil 2 is in the outer layer of the RF coil 20, and the main magnet 11 is in the outer layer of the gradient coil 2. The hollow inner cavity inside the RF coil 20 is the detection space 21.

[0037] The purpose of the present invention is to provide a gradient coil cooling support device and a permanent magnet type magnetic resonance system to solve the problems existing in the prior art. While satisfying the uniform cooling and effective support of the gradient coil, the coil size is optimized to achieve a thinner structure to reduce the occupied area of ​​the magnetic resonance system aperture.

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] Please refer to Figures 1 to 9 An embodiment of the present invention provides a gradient coil cooling support device, including a support heat dissipation layer 1, wherein a first cooling channel 3 is arranged inside the support heat dissipation layer 1. A gradient coil 2 and a protruding structure 6 are fixedly arranged on the inner wall or outer wall of the support heat dissipation layer 1. The gradient coil 2 and the inner wall or outer wall of the support heat dissipation layer 1 can be fixed in a variety of ways, such as using threaded connection, glue bonding, etc. at key positions to ensure a stable connection between the support heat dissipation layer 1 and the gradient coil 2. Figure 2 , Figure 3 and Figure 4The position is shown by the circular hole 4 in the figure. The raised structure 6 is inlaid with the gap 5 of the gradient coil 2 to achieve a tighter fit and fixation between the gradient coil 2 and the supporting heat dissipation layer 1. A second cooling channel 7 connected to the first cooling channel 3 is arranged in the raised structure 6. The gradient coil 2 is inlaid with the raised structure 6 on the inner wall or outer wall of the supporting heat dissipation layer 1, so that the single-layer supporting heat dissipation layer 1 wraps the gradient coil 2 on three sides. When the multiple layers of supporting heat dissipation layers 1 with the gradient coil 2 are installed together from the inside to the outside, the other side of the gradient coil 2 that is not wrapped fits with the next layer of supporting heat dissipation layer 1, and the supporting heat dissipation layer 1 and the raised structure 6 are provided with the first cooling channel 3 and the second cooling channel 7 for circulating the cooling medium, which can form an effective and uniform heat dissipation and cooling of the gradient coil 2 from all directions. In this way, the supporting heat dissipation layer 1 realizes the supporting function for the gradient coil 2, and at the same time, a cooling channel is arranged inside it for dissipating heat and cooling the gradient coil 2, so that the cooling structure and the supporting structure are combined into one, the overall size of the coil is optimized, the space occupied by the magnet in the magnetic resonance system is greatly reduced, and the effective inner diameter of the magnetic resonance system is increased.

[0040] Specifically, the thickness of the support heat dissipation layer 1 is 0.3 mm to 1.5 mm, the thickness of the first cooling channel 3 can be set to only 0.5 mm, and the material used for the support heat dissipation layer is one or more of silicon, copper, carbon fiber, fiberglass, and non-magnetic steel, which can meet the strength requirements on the basis of extremely small size. It is preferred to use non-metallic materials such as silicon, carbon fiber, and fiberglass, which can also avoid the influence of the eddy current effect of metal materials on the magnetic field.

[0041] Furthermore, the number of the first cooling channels 3 inside the supporting heat dissipation layer 1 is n, where n is an integer ≥1 or 2, and the n first cooling channels 3 are evenly arranged along the width direction or the length direction of the supporting heat dissipation layer 1 .

[0042] Since the main magnet 11 and the gradient coil 2 are generally annular cylindrical structures, the supporting heat dissipation layer 1 is also cylindrical or partially arc-shaped. Figure 4 On the supporting heat dissipation layer 1 in a cylindrical structure or a partial arc shape, the first cooling channels 3 are evenly distributed in each degree of the circumference or arc of the cylindrical structure.

[0043] The structure of the first cooling channel 3 in the support heat dissipation layer 1 is not limited to a simple straight line. When a protrusion structure 6 is provided at a position corresponding to the first cooling channel 3, a shunt branch is provided at a position corresponding to the end of one side of the protrusion structure 6 of the first cooling channel 3, which is connected to the second cooling channel 7. At a corresponding position at the end of the other side of the protrusion structure 6, the second cooling channel 7 merges with the same first cooling channel 3 through a reflux branch, or merges with other adjacent first cooling channels 3.

[0044] The supporting heat dissipation layer 1 also includes a liquid supply channel and a liquid outlet channel. The first cooling channel 3 runs through the entire supporting heat dissipation layer 1. The length of the supporting heat dissipation layer 1 matches the design of the gradient coil 2. Both ends of the supporting heat dissipation layer 1 extend from the edge of the gradient coil 2 by about 10 mm, respectively, for connecting the liquid supply channel and the liquid outlet channel. One end of the first cooling channel 3 is connected to the liquid supply channel, and the other end is connected to the liquid outlet channel.

[0045] In one embodiment, please refer to Figure 7 , the liquid supply channel and the liquid outlet channel are respectively arranged in the liquid supply ring 8 and the liquid outlet ring. A liquid supply port 9 is arranged on the outer side of the liquid supply ring 8, and a liquid supply groove 10 as a liquid supply channel is arranged on the inner side of the liquid supply ring 8. The liquid supply port 9 is connected to the liquid supply groove 10. The two side walls of the liquid supply groove 10 extend inwardly for a certain distance, which is used to connect with the support heat dissipation layer 1. A connecting structure for connecting with the support heat dissipation layer 1 is arranged on the extended side wall connected with the support heat dissipation layer 1. The connecting structure can adopt a sealed threaded structure or a rubber strip. The structure of the liquid outlet ring is the same as that of the liquid supply ring 8. A liquid outlet is arranged on the outer side of the liquid outlet ring, and a liquid outlet groove as a liquid outlet channel is arranged on the inner side of the liquid outlet ring. The liquid outlet is connected to the liquid outlet groove. The two side walls of the liquid outlet groove extend inwardly for a certain distance, which is used to connect with the support heat dissipation layer 1. A connecting structure for connecting with the support heat dissipation layer 1 is arranged on the extended side wall connected with the support heat dissipation layer 1. The connecting structure can adopt a sealed threaded structure or a rubber strip.

[0046] The present invention also provides a permanent magnet type magnetic resonance system, comprising the above-mentioned gradient coil cooling support device.

[0047] Specifically, in one embodiment, the permanent magnet type magnetic resonance system includes a main magnet 11 , a cooling support device and a radio frequency coil 20 which are arranged in sequence from the outside to the inside, and the radio frequency coil 20 surrounds to form a detection space 21 .

[0048] The gradient coil 2 includes an X-direction gradient coil, a Y-direction gradient coil, and a Z-direction gradient coil, which are used to accurately locate and image the position and direction of the imaged object or tissue. The number of the supporting heat dissipation layer 1 is multiple layers, and an X-direction gradient coil, a Y-direction gradient coil, or a Z-direction gradient coil is fixedly arranged on the inner wall or outer wall of each supporting heat dissipation layer 1.

[0049] It should be noted that the main magnet 11 is located outside the gradient coil 2 and the radio frequency coil 20 is located inside. The current of the gradient coil 2 can reach tens of amperes and the power can reach thousands of watts, which is the main heat source of the entire system. In order to isolate the heat from being transferred to the main magnet 11 or the radio frequency coil 20 and provide better support strength, an additional support heat dissipation layer 1 can be set between the gradient coil 2 and the main magnet 11, or between the gradient coil 2 and the radio frequency coil 20.

[0050] When the gradient coil 2 is arranged on the outer wall of the support heat dissipation layer 1, although there is no need to dissipate heat for the coil between the gradient coil 2 and the main magnet 11, a support heat dissipation layer 1 without the gradient coil 2 installed can still be arranged. The support heat dissipation layer 1 serves to isolate the heat of the gradient coil 2 from being passively transmitted to the main magnet 11.

[0051] When the gradient coil 2 is arranged on the inner wall of the supporting heat dissipation layer 1, similarly, between the gradient coil 2 and the RF coil 20, although there is no need to dissipate heat from the coil, a supporting heat dissipation layer 1 without the gradient coil 2 can still be arranged, and the supporting heat dissipation layer 1 plays a role in isolating the heat of the gradient coil 2 from being passively transmitted to the RF coil 20.

[0052] In one embodiment, please refer to Figure 1 , the gradient coil 2 is located inside the main magnet 11, the gradient coil 2 is provided with three layers in total, and the support heat dissipation layer 1 is provided with four layers in total. The main magnet 11 is adjacent to the gradient coil A13, and the support heat dissipation layer z12 is in the middle to provide a heat insulation effect. Between the gradient coil A13 and the gradient coil B15, the support heat dissipation layer a14 is bonded to the inside of the gradient coil A13. Between the gradient coil B15 and the gradient coil C17, the support heat dissipation layer b16 is bonded to the inside of the gradient coil B15. Inside the gradient coil C17, the support heat dissipation layer c18 is bonded to the inside of the gradient coil C17 to isolate the heat from being transferred to the RF coil 20 further inside.

[0053] In one embodiment, an insulating layer 19 is disposed on the inner side and the outer side of the RF coil 20 to prevent RF energy leakage and protect the safety of the patient.

[0054] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0055] If the present invention discloses or involves components or structures that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by one-piece molding using a casting process) (except when it is obviously impossible to use an one-piece molding process).

[0056] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in the present invention include states or shapes that are approximate, similar, or close to them.

[0057] Any component provided by the present invention may be assembled from a plurality of separate components, or may be a separate component manufactured by an integral forming process.

[0058] Adaptive changes made according to actual needs are all within the protection scope of the present invention.

[0059] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference numerals in the claims should not be regarded as limiting the claims involved.

[0060] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A gradient coil cooling support device, characterized in that: It includes a supporting heat dissipation layer, wherein a first cooling channel is arranged inside the supporting heat dissipation layer; a gradient coil and a protruding structure are fixedly arranged on the inner wall or the outer wall of the supporting heat dissipation layer, wherein the protruding structure is inlaid and matched with the gap of the gradient coil, and a second cooling channel connected to the first cooling channel is arranged inside the protruding structure.

2. The gradient coil cooling support device according to claim 1, characterized in that: The number of the first cooling channels inside the supporting heat dissipation layer is n, where n is an integer ≥ 1 or 2, and the plurality of first cooling channels are evenly arranged along the width direction or the length direction of the supporting heat dissipation layer.

3. The gradient coil cooling support device according to claim 2, characterized in that: The second cooling channel is communicated with the adjacent first cooling channel.

4. The gradient coil cooling support device according to claim 1, characterized in that: The thickness of the supporting heat dissipation layer is 0.3 mm to 1.5 mm.

5. The gradient coil cooling support device according to claim 1, characterized in that: The material supporting the heat dissipation layer is one or more of silicon, copper, carbon fiber, glass fiber reinforced plastic, and non-magnetic steel.

6. The gradient coil cooling support device according to any one of claims 1 to 5, characterized in that: The supporting heat dissipation layer further includes a liquid supply channel and a liquid outlet channel. One end of the first cooling channel is connected to the liquid supply channel, and the other end is connected to the liquid outlet channel.

7. The gradient coil cooling support device according to claim 6, characterized in that: The liquid supply channel and the liquid outlet channel are respectively arranged at two ends of the supporting heat dissipation layer.

8. A permanent magnet type magnetic resonance system, characterized in that: The invention comprises the gradient coil cooling support device according to any one of claims 1 to 7.

9. The permanent magnet type magnetic resonance system according to claim 8, characterized in that: The invention comprises a main magnet, a cooling support device and a radio frequency coil which are arranged in sequence from the outside to the inside, and the radio frequency coil surrounds to form a detection space.

10. The permanent magnet type magnetic resonance system according to claim 9, characterized in that: The gradient coils include an X-direction gradient coil, a Y-direction gradient coil, and a Z-direction gradient coil. The number of the supporting heat dissipation layers is multiple layers, and an X-direction gradient coil, a Y-direction gradient coil, or a Z-direction gradient coil is fixedly arranged on the inner wall or the outer wall of each supporting heat dissipation layer.

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