CN116953580A - Gradient coil and magnetic resonance imaging apparatus - Google Patents

Abstract

The present application relates to a gradient coil and a magnetic resonance imaging apparatus. The gradient coil includes: the shielding coil comprises at least a first coil path and a second coil path, the first coil path and the second coil path are respectively arranged side by conductors according to a set track, and the tracks corresponding to the first coil path and the tracks corresponding to the second coil path are different. By adopting the gradient coil, the coil path of the shielding coil is divided into at least two paths under the condition that the intensity of the scattered gradient magnetic field is unchanged, and the current on the shielding coil is divided into multiple paths, so that the distribution of the current in the shielding coil can be increased, the intensity of the scattered gradient magnetic field outside the gradient coil is reduced, and the stability and the working time length of the magnetic resonance imaging equipment are ensured.

Description

Gradient coil and magnetic resonance imaging apparatus

Technical Field

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

Background

A magnetic resonance imaging apparatus is an imaging apparatus for medical examination made according to the magnetic resonance principle, which generates magnetic resonance images by scanning different parts of a subject. The gradient coil is one of the core components of the magnetic resonance imaging apparatus, and therefore the design structure of the gradient coil directly affects the quality of the magnetic resonance image.

In the prior art, the gradient coil is generally formed by winding a plurality of conductors, only one winding path of the plurality of conductors is adopted, the winding mode leads to sparse wire distribution of the shielding coil, and concentrated current distribution, so that a larger stray field can be formed on the periphery of the gradient coil. In structural design, the gradient coil is located in a scanning cavity formed by the main magnet, when the magnetic resonance imaging device is driven to perform scanning imaging, an eddy current is generated in metal in the main magnet by an escape field of the gradient coil, when the escape field (gradient magnetic field changing at the periphery of the gradient coil) is large enough, the escape field acts on the magnet coil of the main magnet to heat the magnet coil, so that the magnet pressure rises, the magnetic resonance imaging device cannot work for a long time, the use of a magnetic resonance system is affected, and the main magnet may be quenched in severe cases.

In view of this, there is a need for improvements in the design of existing gradient coils to enable reduced stray fields outside the gradient coils.

Disclosure of Invention

In view of the foregoing, it is desirable to provide a gradient coil and a magnetic resonance imaging apparatus.

The gradient coil comprises a main coil and a shielding coil, the shielding coil is arranged on the periphery of the main coil, the shielding coil comprises at least a first coil path and a second coil path, the first coil path and the second coil path are respectively arranged side by conductors according to a set track, and the tracks corresponding to the first coil path and the tracks corresponding to the second coil path are different.

In one embodiment, the shield coil includes a first coil layer and a second coil layer adjacent to each other, the first end of the conductor in the first coil layer being connected to the first end of the conductor in the second coil layer; the first end of the conductor in the first coil layer is located at the center of the first coil layer and the first end of the conductor in the second coil layer is located at the center of the second coil layer.

In one embodiment, the first coil layer includes a first conductor that forms an outer coil and a second conductor that forms an inner coil, the second coil layer includes a third conductor that forms an outer coil and a fourth conductor that forms an inner coil;

the first end of the first conductor is connected to the first end of the fourth conductor, and the first end of the second conductor is connected to the first end of the third conductor.

In one embodiment, the first coil layer includes a first coil including a fifth conductor that constitutes the outer coil and a sixth conductor that constitutes the inner coil, and a second coil including a seventh conductor that constitutes the outer coil and an eighth conductor that constitutes the inner coil;

the tail end of the fifth conductor is connected with the tail end of the eighth conductor, and the tail end of the sixth conductor is connected with the tail end of the seventh conductor.

In one embodiment, the second end of each conductor in the first coil layer is encapsulated as a port; the second end of each conductor in the second coil layer is encapsulated as a port.

In one embodiment, the first coil layer and the second coil layer are disposed opposite each other or are disposed offset from each other in a vertical direction.

In one embodiment, the coil layer is a saddle coil or a maxwell coil.

In one embodiment, the coil layer includes at least one of an X-axis coil, a Y-axis coil, and a Z-axis coil.

A magnetic resonance imaging apparatus, the magnetic resonance imaging apparatus comprising: the gradient coil, the radio frequency coil and the main magnet of any one of the embodiments above, wherein the gradient coil and the radio frequency coil are arranged in the main magnet;

a main magnet for generating a main magnetic field;

gradient coils for generating a gradient magnetic field and providing a magnetic field environment with the main magnet;

the radio frequency coil is used for transmitting radio frequency pulses to the diagnosis and treatment part of the diagnosis and treatment object in the magnetic field environment so as to excite protons in the diagnosis and treatment object to resonate and acquire magnetic resonance signals of the diagnosis and treatment object.

In one embodiment, the magnetic resonance imaging apparatus further comprises: and the computer imaging system is used for processing the magnetic resonance signals and generating a magnetic resonance image.

The gradient coil comprises a main coil and a shielding coil, wherein the shielding coil is arranged on the periphery of the main coil, the shielding coil comprises at least a first coil path and a second coil path, the first coil path and the second coil path are respectively arranged side by conductors according to a set track, and the track corresponding to the first coil path is different from the track corresponding to the second coil path; the gradient coil can divide the coil path of the shielding coil into at least two paths under the condition that the intensity of the stray gradient magnetic field is unchanged, and the current on the shielding coil is divided into multiple paths, so that the distribution of the current in the shielding coil can be increased, the intensity of the stray gradient magnetic field outside the gradient coil is reduced, and the stability and the working time length of the magnetic resonance imaging equipment are ensured.

Drawings

FIG. 1 is a plan view of a gradient coil in one embodiment;

FIG. 2 is a perspective view of a gradient coil in one embodiment;

FIG. 3 is a schematic diagram of a set-up trajectory corresponding to a coil path included in a main coil or a shield coil in a gradient coil according to an embodiment;

FIG. 4 is a schematic diagram of a set track corresponding to two coil paths included in a coil in an embodiment;

FIG. 5 is a schematic diagram of two coil paths included in a coil according to another embodiment;

FIG. 6 is a schematic diagram of setting tracks corresponding to four coil paths included in a coil in an embodiment;

FIG. 7 is a schematic diagram of a coil path structure including four coils according to another embodiment;

FIG. 8 is a schematic diagram of a connection structure between conductors in different coil layers according to another embodiment;

FIG. 9 is a partial exploded view of a gradient coil in a different axial direction in another embodiment;

FIG. 10 is an expanded schematic diagram of a saddle coil current source for four coil paths in a gradient coil in another embodiment;

FIG. 11 is an internal block diagram of a computer device in one embodiment.

Reference numerals illustrate:

11: a main coil; 12: a shield coil; 121: a first conductor; 122: a second conductor; 123: a third conductor; 124: a fourth conductor; 125: a fifth conductor; 126: a sixth conductor; 127: a seventh conductor; 128: and an eighth conductor.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

The numbering of the components itself, e.g. "first", "second", etc., is used herein merely to distinguish between the described objects and does not have any sequential or technical meaning. The term "coupled" as used herein includes both direct and indirect coupling (coupling), unless otherwise indicated. In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element in question must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

In the present application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

The present embodiment provides a gradient coil including: the main coil 11 and the shielding coil 12, the shielding coil 12 is disposed at the periphery of the main coil 11, the shielding coil 12 includes at least a first coil path and a second coil path, the first coil path and the second coil path are disposed side by conductors according to a set track, and the track corresponding to the first coil path is different from the track corresponding to the second coil path.

In particular, the gradient coils may comprise at least one main coil 11 and at least one shielding coil 12. The main coil 11 and the shield coil 12 in the gradient coil are connected to each other, and the main coil 11 is disposed inside the shield coil 12, that is, the shield coil 12 is disposed at the outer periphery of the main coil 11. The gradient coils described above may generate gradient magnetic fields. Wherein, the head end of the shielding coil 12 and the tail end of the main coil 11 may be connected, and the tail end of the shielding coil 12 and the head end of the main coil 11 may be connected. The main coil 11 and the shield coil 12 may be stacked or may be provided separately at intervals, as long as the main coil 11 and the shield coil 12 are connected to each other. The main coil 11 and the shield coil 12 may each include a plurality of coil layers, and each of the coil layers may be formed by conductor winding. The material of the conductor may be silver, copper, aluminum, iron, alloy, superconducting wire, etc., and the material of the conductor is not limited in this embodiment. In the present embodiment, the shape of the gradient coil may be a flat plate type or a cylindrical type, etc., and the present embodiment is not limited to this shape.

It should be noted that, the shielding coil 12 and the main coil 11 in the gradient coil may each include at least two coil paths, and it may be understood that each of the shielding coil 12 and the main coil 11 may include at least two coil paths, and each of the coil paths may be disposed side by side along a set track by one or more conductors. In this embodiment, the shielding coil 12 in the gradient coil may include at least two coil paths, and it may be further understood that each coil layer in the shielding coil 12 may include at least two coil paths, and each coil path may be disposed by a conductor in parallel according to a set track, which is equivalent to that a plurality of set tracks of each coil layer are disposed in parallel. The conductors can be one or more wires, and each coil path can be formed by winding one or more wires side by side according to corresponding set tracks; the set track may be a spiral pipe type of any track.

It is understood that the track corresponding to the first coil path and the track corresponding to the second coil path are different, and it is understood that the set track corresponding to the first coil path and the set track corresponding to the second coil path do not overlap. The first coil path corresponds to the first end position of the set track and the second coil path corresponds to the first end position of the set track, but the first end position and the second end position are close to each other and do not overlap; the tail end position of the first coil path corresponding to the set track is closer to the tail end position of the second coil path corresponding to the set track, but is not overlapped. The middle track of the first coil path corresponding to the set track and the middle track of the second coil path corresponding to the set track can be independently arranged, and the positions of the first coil path and the second coil path are not adjacent. The middle track of the set track may be a track between the front end back and the rear end front of the set track.

Alternatively, the driving power source corresponding to the first coil path and the driving power source corresponding to the second coil path may be different, i.e., the conductor of the first coil path may be connected to one driving power source and the conductor of the second coil path may be connected to the other driving power source.

Fig. 1 shows a planar development of a gradient coil, which only shows that the gradient coil comprises two main coils 11 and two shielding coils 12, and that the gradient coil comprises two coil paths. However, the gradient coils are not particularly limited to the configuration shown in fig. 1, and the number of the specific main coils 11 and the shield coils 12 included may be arbitrarily set, and the coil paths included may also be arbitrarily set.

Wherein the corresponding perspective view of the gradient coil of fig. 1 can be seen in fig. 2.

For example, fig. 3 is a schematic diagram of a set track corresponding to a coil path included in the main coil 11 or the shielding coil 12 in one coil layer, and the coil layer in fig. 3 is a saddle-shaped coil, but is not limited to this type of coil, and may be other types of coils. According to the coil design mode, the coil can be arranged according to two coil paths, and two corresponding set track schematic diagrams are shown in fig. 4. The plurality of conductors are wound along two set tracks to form an inner coil and an outer coil, and fig. 5 is a schematic structural diagram of the inner coil and the outer coil formed by winding the plurality of conductors.

In the gradient coil, the gradient coil comprises a main coil and a shielding coil, a first accommodating cavity can be formed in a surrounding mode, and the shielding coil is arranged on the periphery of the main coil; the shielding coil can encircle to form a second accommodating cavity, the second accommodating cavity is sleeved on the periphery of the first accommodating cavity, the shielding coil comprises at least a first coil path and a second coil path, the first coil path and the second coil path are respectively arranged side by conductors according to a set track, and the track corresponding to the first coil path is different from the track corresponding to the second coil path; the gradient coil can divide the coil path of the shielding coil into at least two paths under the condition that the intensity of the stray gradient magnetic field is unchanged, and the current on the shielding coil is divided into multiple paths for transmission, so that the distribution of the current in the shielding coil can be increased, the intensity of the stray gradient magnetic field outside the gradient coil is reduced, and the stability and the working time length of the magnetic resonance imaging equipment are ensured; meanwhile, when the magnetic resonance imaging equipment works for a long time, the gradient coil can reduce the intensity of the dissipated gradient magnetic field through a plurality of coil paths so as to avoid the magnet quench in the magnetic resonance imaging equipment and influence the use of the magnetic resonance imaging equipment, and in addition, the gradient coil can also reduce the heating problem caused by overlarge driving current due to the arrangement of the shielding coil and the main coil through multipath arrangement, thereby reducing the damage speed of the gradient coil and prolonging the service life of the gradient coil.

As one example, the shield coil 12 includes a first coil layer and a second coil layer, the first coil layer and the second coil layer being adjacent, a first end of a conductor in the first coil layer being connected to a first end of a conductor in the second coil layer; the first end of the conductor in the first coil layer is located at the center of the first coil layer and the first end of the conductor in the second coil layer is located at the center of the second coil layer.

In this embodiment, the shielding coil 12 in the gradient coil may include two adjacent coil layers, a first coil layer and a second coil layer, respectively. The first coil layer and the second coil layer may each include a plurality of conductors. The leading or trailing ends of the plurality of conductors in the first coil layer may be referred to as the first ends of the conductors in the first coil layer; the leading or trailing ends of the plurality of conductors in the second coil layer may be referred to as first ends of the conductors in the second coil layer, and the first ends of the conductors in the first coil layer may be connected with the first ends of the conductors in the second coil layer. Wherein the first ends of the plurality of conductors in the first coil layer may be located at the center of the first coil layer and the first ends of the plurality of conductors in the second coil layer may be located at the center of the second coil layer.

It should be noted that, the connection manner between the first end of the conductor in the first coil layer and the first end of the conductor in the second coil layer may be determined according to the type of the conductor, and may be a twisted connection, a pressed connection, a welding connection, or the like. The gradient coils may have a cylindrical structure, and each coil layer may have a coaxial cylindrical configuration.

The shielding coil in the gradient coil comprises two adjacent coil layers, and the first ends of the conductors in the two coil layers are connected with each other, so that the gradient coil can reduce the volume of the coil through a layered design structure, and meanwhile, the inductance of the coil can be increased.

As one example, with continued reference to fig. 1, the shield coil and the main coil of fig. 1 each include two coil layers. In fig. 1, one shield coil 12 has a partial structure in a solid frame, and a first coil layer and a second coil layer in the shield coil 12 are separated by a dotted line, so that the first coil layer is located above the second coil layer and the second coil layer is located below the first coil layer. The first coil layer in the shield coil 12 includes a first conductor 121 constituting an outer coil and a second conductor 122 constituting an inner coil, and the second coil layer in the shield coil 12 includes a third conductor 123 constituting an outer coil and a fourth conductor 124 constituting an inner coil; the first end of the first conductor 121 is connected to the first end of the fourth conductor 124, and the first end of the second conductor 122 is connected to the first end of the third conductor 123.

Specifically, the shield coil 12 in the gradient coil includes two coil layers, a first coil layer and a second coil layer, respectively. Each coil layer may include an even number of coil paths, such as two coil paths, four coil paths, etc., with the plurality of coil paths being disposed side-by-side. Fig. 6 is a schematic structural diagram of four set tracks corresponding to four coil paths included in one coil layer, and a corresponding structure of four coil paths formed by winding a plurality of conductors along the four set tracks is shown in fig. 7. Alternatively, the coil layers formed by the multiple coil paths may be referred to as an outer coil, and the coils other than the outermost coil may be referred to as inner coils.

In this embodiment, the first coil layer may include a first conductor 121 constituting the outer coil and a second conductor 122 constituting the inner coil. The second coil layer may include a third conductor 123 constituting the outer coil and a fourth conductor 124 constituting the inner coil. The first conductor 121 and the fourth conductor 124 may be connected, and the second conductor 122 and the third conductor 123 may be connected, but in this embodiment, the first end of the first conductor 121 is connected to the first end of the fourth conductor 124, and the first end of the second conductor 122 is connected to the first end of the third conductor 123, that is, the conductor constituting the outer coil in one coil layer is connected to the conductor constituting the inner coil in the other coil layer, or the conductor constituting the inner coil in one coil layer is connected to the conductor constituting the outer coil in the other coil layer.

With continued reference to fig. 4, fig. 4 may be understood as a coil layer including two coil paths, and if the coil layer is set as a first coil layer, the first coil layer includes a first coil including a fifth conductor 125 forming an outer coil and a sixth conductor 126 forming an inner coil, and the second coil includes a seventh conductor 127 forming an outer coil and an eighth conductor 128 forming an inner coil; the tail end of the fifth conductor 125 is connected to the tail end of the eighth conductor 128, and the tail end of the sixth conductor 126 is connected to the tail end of the seventh conductor 127.

It should be noted that each coil layer may include a plurality of coils, and in this embodiment, each coil layer may include two coils. If the first coil layer includes a first coil and a second coil, the first coil may include a fifth conductor 125 that constitutes an outer coil and a sixth conductor 126 that constitutes an inner coil, and the second coil may include a seventh conductor 127 that constitutes an outer coil and an eighth conductor 128 that constitutes an inner coil. The first coil and the second coil in the first coil layer may be respectively provided as an inner coil or an outer coil, which is not limited; but in fig. 4 the first coil is arranged as an outer coil in the first coil layer and the second coil is arranged as an inner coil in the first coil layer. Wherein the first coil and the second coil may be two adjacent coils in the first coil layer. The first conductor 121 may include a fifth conductor 125 and a seventh conductor 127, and the first conductor 121 may include a sixth conductor 126 and an eighth conductor 128.

Further, in the present embodiment, the driving current flowing through the fifth conductor 125 forming the outer coil and the sixth conductor 126 forming the inner coil is the same, and the driving current flowing through the seventh conductor 127 forming the outer coil and the eighth conductor 128 forming the inner coil is the same, that is: the first coil path and the second coil path have different corresponding tracks, but have the same driving current, so that a uniform shielding magnetic field is formed. In the prior art, in order to improve the shielding effect, the winding density (winding turns) of the shielding coil is often increased, and the winding density of the main coil corresponding to the winding density is also required to be increased, however, the setting method reduces the intensity of the effective gradient field while improving the shielding effect (the shielding field generated by the shielding coil has obvious inhibition on the main gradient field generated by the main coil). In the embodiment of the application, the first coil path and the second coil path which are arranged side by side can ensure the intensity of the effective gradient field and improve the shielding effect. On the other hand, the existing design method requires a strong driving current, thereby causing the coil to generate heat significantly. The embodiment can obviously reduce the driving current on a single conductor, improve the working time length and the stability of the coil, and reduce the requirement on equipment cooling.

In the present embodiment, the tail end of the fifth conductor 125 is connected to the tail end of the eighth conductor 128, and the tail end of the sixth conductor 126 is connected to the tail end of the seventh conductor 127, where the tail ends of the fifth conductor 125 and the sixth conductor 126 may be located at the edge of the first coil layer, and the tail ends of the seventh conductor 127 and the eighth conductor 128 may be located at the edge of the first coil layer. That is, in two adjacent coils of each coil layer, the conductor constituting the outer coil in one coil is connected to the conductor constituting the inner coil in the other coil, or the conductor constituting the inner coil in one coil is connected to the conductor constituting the outer coil in the other coil.

For example, if the gradient coil comprises two coil layers, each coil layer comprises one coil; the conductor of one coil layer forming the outer coil is connected with the conductor of the other coil layer forming the inner coil, or the conductor of one coil layer forming the inner coil is connected with the conductor of the other coil layer forming the outer coil, and the specific connection structure is shown in fig. 8.

Fig. 9 is a partial exploded view of a gradient coil in different axial directions. The shielding coil 12 in the gradient coil comprises two adjacent coil layers, and the first ends of the conductors in the two coil layers are connected to each other, so that the gradient coil can reduce the coil volume by the layered design structure, while the inductance of the coil can also be increased.

As one example, the second end of each conductor in the first coil layer is encapsulated as a port; the second end of each conductor in the second coil layer is encapsulated as a port.

In particular, the second end of each conductor in the first coil layer in the gradient coil may be located at an edge of the first coil layer, and it is also understood that each conductor in the first coil layer includes two ends, one end of each conductor in the first coil layer is located at a center of the first coil layer, and the other end of each conductor not located at the center of the first coil layer may be referred to as the second end of each conductor in the first coil layer.

In this embodiment, each of the first coil layer and the second coil layer may include a plurality of coils, and the second ends of the conductors in each of the coils may be respectively encapsulated as one port. With continued reference to fig. 8, the second ends of the conductors in the first and second coil layers are labeled in fig. 8. The number of coils contained in the first coil layer may be equal to the number of coils contained in the second coil layer.

The first coil layer and the second coil layer are arranged opposite to each other or are arranged in a staggered manner in the vertical direction.

It will be appreciated that arranging the first coil layer and the second coil layer opposite in the vertical direction may allow for a simple construction of the gradient coil. The first coil layer and the second coil layer can be arranged in a staggered manner in the vertical direction, so that conductors in the two coil layers are distributed in a staggered manner, and gradient fields in different directions can be generated by the gradient coil, so that different gradient performance requirements of the gradient coil are met.

In addition, the coil layer is a saddle coil or a maxwell coil, and the coil layer includes at least one of an X-axis coil, a Y-axis coil, and a Z-axis coil.

The gradient coils may include an X-axis coil, a Y-axis coil, and a Z-axis coil, and a gradient magnetic field in a three-dimensional direction is generated by the X-axis coil, the Y-axis coil, and the Z-axis coil. The X-axis coil can generate a gradient magnetic field in the X direction, the Y-axis coil can generate a gradient magnetic field in the Y direction, and the Z-axis coil can generate a gradient magnetic field in the Z direction. In this embodiment, the X-axis coil, the Y-axis coil, and the Z-axis coil may each be of saddle coil design or maxwell coil design.

The saddle coil and/or maxwell coil in the gradient coil can be set according to the coil design mode so as to reduce the intensity of the gradient magnetic field dissipated by the gradient coil. And, the coil layers in the gradient coils may include at least one of an X-axis coil, a Y-axis coil, and a Z-axis coil, that is, at least one of the gradient coils is configured in the above-described coil design manner to reduce the intensity of the gradient magnetic field dissipated by the gradient coils.

With continued reference to fig. 1, an expanded schematic diagram of the gradient coil connection current source is shown. Alternatively, one current source is connected to each gradient coil, and one gradient coil is shown in fig. 1, and thus one gradient coil is also shown in fig. 1. Wherein fig. 1 shows an expanded schematic of saddle coil current-receiving sources for two coil paths in a gradient coil; fig. 10 is an expanded schematic diagram of saddle coil current-carrying sources for four coil paths in a gradient coil.

Meanwhile, the gradient coils can be formed by forming the coil layers in the main coil 11 and the shielding coil 12 into a whole structure. Wherein, each coil layer in the main coil 11 and the shielding coil 12 can be rolled into cylinder structures with different sizes through a plate rolling machine, and then each coil layer in the main coil 11 and the shielding coil 12 is coaxially assembled and then encapsulated through epoxy resin liquid to form a gradient coil, so as to isolate air and achieve the purposes of moisture resistance, water resistance, oil resistance, dust resistance, damp resistance and ageing resistance of the coil.

The gradient coil can divide the coil path of the shielding coil into at least two paths and divide the current on the shielding coil into multiple paths, so that the distribution of the current in the shielding coil can be increased, the intensity of a stray gradient magnetic field outside the gradient coil is reduced, and the stability and the working time length of the magnetic resonance imaging equipment for forming the magnetic field are ensured; meanwhile, the gradient coil can also be arranged in a plurality of ways, so that the heating problem of the shielding coil and the main coil is reduced to a certain extent, the damage speed of the gradient coil is reduced, and the service life of the gradient coil is prolonged.

The present application provides a magnetic resonance imaging apparatus comprising: a gradient coil, a radio frequency coil, and a main magnet as provided in any one of the embodiments above;

wherein the gradient coil and the radio frequency coil are arranged in the main magnet; a main magnet for generating a main magnetic field; gradient coils for generating a gradient magnetic field and providing a magnetic field environment with the main magnet; the radio frequency coil is used for transmitting radio frequency pulses to the diagnosis and treatment part of the diagnosis and treatment object in the magnetic field environment so as to excite protons in the diagnosis and treatment object to resonate and acquire magnetic resonance signals of the diagnosis and treatment object.

In particular, a main magnet in a magnetic resonance imaging apparatus may generate a main magnetic field to align magnetic nuclear spins within a subject. The main magnet may be a superconducting magnet, a permanent magnet, and/or a resistive electromagnet, etc. Meanwhile, gradient coils in the magnetic resonance imaging device can generate gradient magnetic fields to form a mixed magnetic field environment of a main magnetic field and the gradient magnetic field, so that imaging and coding are facilitated. The above-described mixed magnetic field environment may be a static homogeneous magnetic field environment.

It should be noted that, since nuclei such as hydrogen nuclei, whose protons have spin movements, similar to a small magnet, exist in the subject, the spin axes of the small magnets are not necessarily regular, and if an external magnetic field is applied, the small magnets are rearranged according to the magnetic lines of the external magnetic field, specifically, are arranged in two directions parallel or antiparallel to the magnetic lines of the external magnetic field, the direction parallel to the magnetic lines of the external magnetic field is referred to as a positive longitudinal axis, and the direction antiparallel to the magnetic lines of the external magnetic field is referred to as a negative longitudinal axis. When nuclei in an external magnetic field are excited with a radio frequency pulse, the spin axes of the nuclei deviate from the positive or negative longitudinal axis, producing resonance.

Further, in the magnetic field environment, the radio frequency coil in the magnetic resonance imaging device can emit radio frequency pulse to the diagnosis and treatment part of the diagnosis and treatment object, after the radio frequency coil stops emitting the radio frequency pulse, the excited atomic nuclei emit magnetic resonance signals, the absorbed energy is gradually released in the form of electromagnetic waves, and the phase and the energy level of the magnetic resonance signals are the same as those of the radio frequency pulse before excitation.

Meanwhile, the magnetic resonance imaging apparatus further includes: and the computer imaging system is used for processing the magnetic resonance signals and generating a magnetic resonance image.

It will be appreciated that a computer imaging system in a magnetic resonance imaging apparatus may perform preprocessing, contrast processing, conversion processing, analysis processing and/or arithmetic processing, etc. on magnetic resonance signals received by the radio frequency coils to generate magnetic resonance images. The magnetic resonance image may be a two-dimensional image or a three-dimensional image.

The computer imaging system is specifically used for carrying out space coding on the magnetic resonance signals and generating magnetic resonance images.

The gradient coil in the magnetic resonance imaging device can divide the coil path of the shielding coil into at least two paths, and divide the current on the shielding coil into multiple paths for transmission, so that the distribution of the current in the shielding coil can be increased, the intensity of a stray gradient magnetic field outside the gradient coil can be reduced when the magnetic resonance imaging device works for a long time, the magnet quench in the magnetic resonance imaging device can be avoided, the use of the magnetic resonance imaging device is influenced, the damage speed of the magnetic resonance imaging device is further reduced, the service life of the gradient coil is prolonged, and the stability and the usability of the magnetic resonance imaging device are improved.

In one embodiment, a computer imaging system is provided. The computer imaging system includes a computer device, which may be a server, and an internal structural diagram of the computer device may be as shown in fig. 11. The computer device includes a processor, a memory, and a network interface connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The database of the computer device is used for storing magnetic resonance signals. The network interface of the computer device is for communicating with an external endpoint via a network connection. The computer program is executed by the processor to perform processing of the magnetic resonance signals to generate a magnetic resonance image.

It will be appreciated by those skilled in the art that the structure shown in FIG. 11 is merely a block diagram of some of the structures associated with the present inventive arrangements and is not limiting of the computer device to which the present inventive arrangements may be applied, and that a particular computer device may include more or fewer components than shown, or may combine some of the components, or have a different arrangement of components.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims (10)

1. The gradient coil is characterized by comprising a main coil (11) and a shielding coil (12), wherein the shielding coil (12) is arranged on the periphery of the main coil (11), the shielding coil (12) comprises at least a first coil path and a second coil path, the first coil path and the second coil path are respectively arranged side by conductors according to a set track, and the tracks corresponding to the first coil path and the tracks corresponding to the second coil path are different.

2. Gradient coil according to claim 1, characterized in that the shielding coil (12) comprises a first coil layer and a second coil layer, which are adjacent, a first end of a conductor in the first coil layer being connected with a first end of a conductor in the second coil layer; the first end of the conductor in the first coil layer is located at the center of the first coil layer, and the first end of the conductor in the second coil layer is located at the center of the second coil layer.

3. Gradient coil according to claim 2, characterized in that the first coil layer comprises a first conductor (121) constituting an outer coil and a second conductor (122) constituting an inner coil, the second coil layer comprising a third conductor (123) constituting an outer coil and a fourth conductor (124) constituting an inner coil;

the first end of the first conductor (121) is connected with the first end of the fourth conductor (124), and the first end of the second conductor (122) is connected with the first end of the third conductor (123).

4. A gradient coil according to claim 2 or 3, wherein the first coil layer comprises a first coil comprising a fifth conductor (125) constituting an outer coil and a sixth conductor (126) constituting an inner coil, and a second coil comprising a seventh conductor (127) constituting an outer coil and an eighth conductor (128) constituting an inner coil;

the tail end of the fifth conductor (125) is connected with the tail end of the eighth conductor (128), and the tail end of the sixth conductor (126) is connected with the tail end of the seventh conductor (127).

5. A gradient coil according to claim 2 or 3, wherein the second end of each conductor in the first coil layer is encapsulated as a port; the second end of each conductor in the second coil layer is encapsulated as a port.

6. A gradient coil according to claim 2 or 3, wherein the first and second coil layers are arranged vertically opposite or offset.

7. A gradient coil according to any one of claims 1-3, wherein the coil layer is a saddle coil or a maxwell coil.

8. A gradient coil according to any one of claims 1-3, wherein the coil layer comprises at least one of an X-axis coil, a Y-axis coil and a Z-axis coil.

9. A magnetic resonance imaging apparatus, the apparatus comprising: gradient coil, radio frequency coil and main magnet according to any of the preceding claims 1-8, said gradient coil and said radio frequency coil being arranged within said main magnet;

the main magnet is used for generating a main magnetic field;

the gradient coil is used for generating a gradient magnetic field and providing a magnetic field environment together with the main magnet;

the radio frequency coil is used for transmitting radio frequency pulse to a diagnosis and treatment part of a diagnosis and treatment object in the magnetic field environment so as to excite protons in the diagnosis and treatment object to resonate and acquire magnetic resonance signals of the diagnosis and treatment object.

10. The magnetic resonance imaging apparatus according to claim 9, wherein the apparatus further comprises: and the computer imaging system is used for processing the magnetic resonance signals and generating a magnetic resonance image.