Magnetic resonance device and its control method

Abstract

The present invention relates to a magnetic resonance device, comprising: a superconducting magnet having a magnet bore, a main coil in the superconducting magnet, the main coil being capable of generating a uniform region with at least two scan fields of view within the magnet bore; at least two gradient coils arranged in the magnet bore along the axial direction; and at least two radio frequency coils arranged in the magnet bore along the axial direction and corresponding to at least two of the radio frequency coils respectively. By generating a uniform region with at least two scan fields of view by the superconducting magnet in cooperation with at least two radio frequency coils, at least two scan fields of view can respectively correspond to multiple imaging sites, so as to realize simultaneous scanning of multiple imaging sites, or realize one-time scanning of a larger imaging site, improve the scanning speed and efficiency, and facilitate use.

Description

Technical Field

[0001] The present invention relates to the technical field of medical imaging devices, and particularly to a magnetic resonance device and a control method thereof. Background Art

[0002] Conventional nuclear magnetic resonance medical devices usually use superconducting magnets to generate a stable background magnetic field in a certain space. For example, superconducting magnets with a field strength of 0.35T to 7.0T can usually generate a stable magnetic field region with a considerable volume near the geometric center of the superconducting magnet, that is, the region of interest for scanning and imaging. The magnetic field in the Z direction (i.e., the axial direction of the cylindrical magnet) in this region is very uniform. In this stable magnetic field region, a gradient field is generated by cooperating with gradient coils, and a radio frequency field is generated by corresponding radio frequency coils (including transmitting coils and receiving coils). Under the control of a magnetic resonance controller, these components can scan and image the corresponding tissue parts of the scanned object located in this region.

[0003] In order to meet the requirements of magnetic resonance device scanning and imaging, the magnetic field uniformity in the Z direction in the space of the magnet center uniform region, that is, the stable magnetic field region, is very good. Usually, in a spherical uniform region, its peak non-uniformity (the ratio of the difference between the highest and lowest magnetic fields in the region to the central field value), that is, pk-pk (magnetic field peak uniformity in the Z-axis direction) does not exceed the level of 10 ppm (one in a million). And the spatial size of the magnet center uniform region is the key to the design of the superconducting magnet. The larger the central uniform region, the larger the scanning field of view, the larger the tissue range that can be scanned at one time, and the faster the imaging speed.

[0004] However, currently, a magnetic resonance device usually has a single scanning field of view in the stable magnetic field region. The scanning range of a single scanning field of view is limited, and it can only image one imaging part or a smaller imaging part. When the number of imaging parts is at least two, or the volume of the imaging part is large, a single scanning field of view cannot meet the scanning requirements, and it is necessary to reciprocally move the examination bed to drive the scanned object to move, so that the imaging parts of the scanned object are respectively aligned with the scanning field of view for imaging. This will reduce the scanning speed and efficiency and is not convenient to use. Summary of the Invention

[0005] Based on this, in view of the problem of low scanning speed caused by a single scanning field of view currently, it is necessary to provide a magnetic resonance device and a control method thereof that can improve the scanning speed.

[0006] A magnetic resonance device includes:

[0007] A superconducting magnet having a main coil therein, the main coil forming a magnet bore, and the main coil being capable of generating one or more uniform regions in the magnet bore;

[0008] At least one set of gradient coils, disposed axially in the magnet bore; and

[0009] At least one set of radio frequency coils, disposed axially in the magnet bore and cooperating with at least one set of the gradient coils, and at least one set of the radio frequency coils is capable of forming at least two radio frequency fields;

[0010] The homogeneous region cooperates with at least two of the radio frequency fields, such that the magnetic resonance device has at least two scanning fields of view.

[0011] In one embodiment, the number of the homogeneous regions is one, and the range of the homogeneous region is greater than or equal to the range of the at least two scanning fields of view.

[0012] In one embodiment, two sets of the gradient coils and two sets of the radio frequency coils are respectively disposed at intervals in the magnet bore;

[0013] Alternatively, two sets of the radio frequency coils and one set of the gradient coils are disposed at intervals in the magnet bore.

[0014] In one embodiment, a plurality of the homogeneous regions are disposed at intervals along the axial direction of the magnet bore, and the distance between two adjacent homogeneous regions is 0.1 to 5 times the axial length of the homogeneous region.

[0015] In one embodiment, the homogeneous regions are symmetrically distributed about the center of the superconducting magnet; or, the homogeneous regions are asymmetrically distributed about the center of the superconducting magnet.

[0016] In one embodiment, the main coils of the superconducting magnet form two of the homogeneous regions, each homogeneous region corresponding to one of the scanning fields of view, and one set of gradient coils and one set of radio frequency coils are respectively disposed in each homogeneous region.

[0017] In one embodiment, two of the gradient coils corresponding to different homogeneous regions are of an integral structure, or two of the gradient coils corresponding to different homogeneous regions are disposed at intervals.

[0018] In one embodiment, the main coils include a first main coil and a second main coil, the first main coil is located at an end of the magnet bore, the second main coil is located in a central region of the magnet bore, and the dimension of the first main coil along the radial direction of the magnet bore is greater than the dimension of the second main coil along the radial direction of the magnet bore.

[0019] A control method for a magnetic resonance device, the magnetic resonance device including a superconducting magnet, gradient coils, and radio frequency coils, the superconducting magnet including a plurality of sets of main coils disposed axially, the plurality of sets of main coils forming a magnet bore, and the gradient coils and the radio frequency coils being disposed in the magnet bore;

[0020] The control method includes:

[0021] Exciting multiple groups of the main coils to generate a uniform magnetic field region in the magnet bore, and the uniform magnetic field region covers a first region and a second region;

[0022] Driving the RF coil to generate a first RF field in the first region and a second RF field in the second region simultaneously; driving the gradient coil to generate a first gradient field in the first region and a second gradient field in the second region simultaneously;

[0023] Alternatively, driving the RF coil to generate a first RF field in the first region during a first time period and a second RF field in the second region during a second time period; driving the gradient coil to generate a first gradient field in the first region during the first time period and a second gradient field in the second region during the second time period.

[0024] In one embodiment, the magnetic resonance device further includes a scanning bed, and the control method further includes:

[0025] During a first time period, driving the scanning bed to the first region to perform imaging of a first field of view;

[0026] During a second time period, driving the scanning bed to the second region to perform imaging of a second field of view;

[0027] Alternatively, driving the scanning bed into the first region and the second region and performing imaging of the first field of view and the second field of view.

[0028] After adopting the above technical solution, the present invention has at least the following technical effects:

[0029] In the magnetic resonance device of the present invention, the main coil of the superconducting magnet can generate a uniform region of a constant magnetic field in the magnet bore, and this uniform region can be used for at least two fields of view and for imaging. Moreover, the RF coil arranged in the magnet bore generates at least two (groups) of RF fields in different regions, and each RF coil corresponds to one field of view. At least two groups of RF fields can be matched with the above uniform region, so that the parts in at least two fields of view can be scanned and imaged. By using the uniform region with at least two fields of view generated by the superconducting magnet in cooperation with at least two groups of RF fields, the problem that the single field of view currently affects the scanning speed is effectively solved, such that at least two fields of view can respectively correspond to multiple imaging parts, enabling simultaneous scanning of multiple imaging parts, or enabling one-time scanning of a larger imaging part, improving the scanning speed and efficiency, and being convenient to use. Description of the Drawings

[0030] Figure 1 It is a schematic diagram of the magnetic resonance device according to the first embodiment of the present invention;

[0031] Figure 2 Schematic diagram of a superconducting magnet generating two uniform regions in the magnetic resonance device shown; Figure 1 Schematic diagram of the magnetic resonance device according to the second embodiment of the present invention;

[0032] Figure 3 Schematic diagram of the magnetic resonance device according to the third embodiment of the present invention;

[0033] Figure 4 Schematic diagram of an embodiment of the main coil in the magnetic resonance device shown;

[0034] Figure 5 Schematic diagram of an embodiment of the main coil in the magnetic resonance device shown; Figure 1 Schematic diagram of an embodiment of the main coil in the magnetic resonance device shown.

[0035] Wherein: 100, magnetic resonance device; 110, superconducting magnet; 111, main coil; 112, uniform region; 120, gradient coil; 130, radio frequency coil; 131, transmitting coil; 132, receiving coil; 200, scanned object. Detailed implementation manners

[0036] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following will describe the detailed implementation manners of the present invention with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0037] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, 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 thus should not be construed as limiting the present invention.

[0038] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0039] In the present invention, unless otherwise clearly specified or limited, terms such as "installed", "connected", "linked", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0041] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0042] See Figures 1 to 4 , the present invention provides a magnetic resonance device 100. The magnetic resonance device 100 is used to scan an imaging part to obtain a magnetic resonance signal of the imaging part, and medical staff can diagnose a scanned object 200 based on the image information reconstructed from the magnetic resonance signal. Optionally, the imaging part here mainly refers to the area to be imaged or the area of interest of the doctor of the scanned object 200. The imaging part may be tissue parts such as the head, brain, limbs, abdomen, spine, neck, chest, etc. of the scanned object 200, or may also be human organs such as the heart, kidneys, lower limbs, bladder, etc.

[0043] It can be understood that currently, magnetic resonance equipment usually has a scanning field of view in the constant magnetic field region. The scanning range of a single scanning field of view is limited, and it can only image one imaging part or a relatively small imaging part. When the number of imaging parts is at least two, or when the volume of the imaging part is relatively large, a single scanning field of view cannot meet the scanning requirements, and it is necessary to reciprocally move the examination bed to drive the scanning object to move, so that the imaging parts of the scanning object are respectively aligned with the scanning field of view for imaging. This will reduce the scanning speed and efficiency and is not convenient for use.

[0044] For this reason, the present invention provides a new type of magnetic resonance equipment 100. This magnetic resonance equipment 100 can simultaneously scan and image at least two imaging parts, or simultaneously scan two different regions of a relatively large imaging part in a period of time, without multiple scans, improving the scanning speed and efficiency and being convenient for use. The specific structure of the magnetic resonance equipment 100 will be introduced in detail below.

[0045] See Figures 1 to 4 , in an embodiment, the magnetic resonance equipment 100 includes a superconducting magnet 110, at least one set of gradient coils 120, and at least one set of radio frequency coils 130. The superconducting magnet 110 has a main coil 111 and a shielding coil located outside the main coil 111. The main coil 111 can form one or more magnet holes, and after excitation, the main coil 111 generates a uniform magnetic field region 112 in the magnet holes. At least one set of gradient coils 120 is arranged in the magnet holes along the axial direction, and at least one set of radio frequency coils 130 is arranged in the magnet holes along the axial direction and cooperates with at least one set of gradient coils 120. At least one set of radio frequency coils 130 forms at least two radio frequency fields. The uniform region 112 cooperates with at least two radio frequency fields, so that the magnetic resonance equipment 110 forms at least two scanning fields of view.

[0046] The superconducting magnet 110 is arranged in a hollow cylindrical shape, and the hollow part of the superconducting magnet 110 is a magnet hole extending along the axial direction. The superconducting magnet 110 has a main coil 111 and a shielding coil inside. The main coil 111 can generate a uniform region 112 of a constant magnetic field in the magnet hole, and the shielding coil can be used to suppress the interference of external electromagnetic waves on the uniform region 112. When the magnetic resonance equipment 100 is in use, the scanning bed can drive the scanning object 200 to move in the magnet hole, so that the imaging part of the scanning object 200 is located in the uniform region 112 of the magnet hole to scan and image the imaging part.

[0047] Moreover, after the superconducting magnet 110 forms a uniform region 112 in the magnet bore through the main coil 111, the uniform region 112 can provide a scanning space for at least two scanning fields of view. It should be noted that one scanning field of view can image one imaging part, and at least two scanning fields of view can scan and image at least two parts to be imaged. In this way, the magnetic resonance device 100 can simultaneously image at least two imaging parts of the scanning object 200 through the uniform region 112 of the superconducting magnet 110, improving the scanning efficiency and speed.

[0048] The gradient coil 120 is disposed on one side of the superconducting magnet 110 facing the magnet bore, that is, the gradient coil 120 is located in the magnet bore of the superconducting magnet 110 and on the inner wall of the magnet bore of the superconducting magnet 110. The gradient coil 120 is used to generate a gradient field in the magnet bore. The radio frequency coil 130 is disposed on one side of the superconducting magnet 110 facing the magnet bore, that is, the radio frequency coil 130 is located in the magnet bore of the superconducting magnet 110, and moreover, the radio frequency coil 130 is located on the inner wall on the side of the gradient coil 120 away from the magnet bore. The radio frequency coil 130 is used to generate a radio frequency field in the magnet bore. Moreover, the superconducting magnet 110, the gradient coil 120, and the radio frequency coil 130 are fixedly assembled coaxially.

[0049] At least one set of gradient coils 120 is disposed along the axial direction of the magnet bore. In this way, the gradient coil 120 can correspond to the uniform region 112 generated by the main coil 111 in the magnet bore, so that the gradient field can cover the entire uniform region 112. It can be understood that the number of gradient coils 120 is not limited in principle, as long as the generated gradient field can cover the uniform region. At least one set of radio frequency coils 130 is disposed along the axial direction of the magnet bore and generates at least two radio frequency fields along the axial direction of the magnet bore. In this way, the radio frequency coil can correspond to the uniform region 112 generated by the main coil 111 in the magnet bore, so that the radio frequency field can cover the entire uniform region 112. It can be understood that the number of radio frequency coils 130 is not limited in principle, as long as the generated radio frequency field can cover the uniform region.

[0050] Moreover, the radio frequency coils 130 are distributed corresponding to the gradient coils 120. That is to say, at least two radio frequency fields of the radio frequency coils 130 are in a corresponding relationship with the gradient coils 120. In this way, the radio frequency fields generated by the radio frequency coils 130 can act together with the gradient fields generated by the gradient coils 120 in the uniform region 112 generated by the main coil 111 to image the imaging parts of the scanning object 200. In the uniform region 112, each radio frequency field corresponds to one scanning field of view. By increasing the number of scanning fields of view through the radio frequency coils 130, the purpose of increasing the scanning fields of view is achieved, so as to simultaneously scan and image at least two imaging parts, realizing parallel scanning and improving the scanning speed and efficiency.

[0051] The magnetic resonance device 100 of the above embodiment generates a uniform region 112 with at least two scanning fields of view through the superconducting magnet 110, in cooperation with at least two radio frequency fields, effectively solving the problem that the single scanning field of view currently affects the scanning speed, enabling at least two scanning fields of view to respectively correspond to multiple imaging parts, realizing simultaneous scanning of multiple imaging parts, or realizing one-time scanning of a larger imaging part, improving the scanning speed and efficiency, and being convenient to use.

[0052] In one embodiment, the number of gradient coils 120 is at least two, and the at least two gradient coils 120 are arranged along the axial direction of the magnet bore. In this way, the at least two gradient coils 120 can correspond to the uniform region 112 generated by the main coil 111 in the magnet bore, so that the gradient field can cover the entire uniform region 112. The number of radio frequency coils 130 is also two, and the at least two radio frequency coils 130 are arranged along the axial direction of the magnet bore. In this way, the at least two radio frequency coils 130 can correspond to the uniform region 112 generated by the main coil 111 in the magnet bore, so that the radio frequency field can cover the entire uniform region 112.

[0053] Moreover, the at least two radio frequency coils 130 are distributed corresponding to the at least two gradient coils 120. That is to say, the radio frequency coils 130 and the gradient coils 120 are in a corresponding relationship. In this way, the radio frequency field generated by the radio frequency coils 130 can be superimposed with the gradient field generated by the gradient coils 120 in the uniform region 112 generated by the main coil 111 to realize imaging of the imaging part of the scanning object 200. In the uniform region 112, each radio frequency coil 130 corresponds to a scanning field of view. By increasing the number of radio frequency coils 130, the purpose of increasing the scanning field of view is achieved, so as to simultaneously scan and image at least two imaging parts, realizing parallel scanning and improving the scanning speed and efficiency.

[0054] In one embodiment, two sets of gradient coils 120 and two sets of radio frequency coils 130 are arranged at intervals in the magnet bore. That is to say, the two sets of radio frequency coils 130 generate two radio frequency fields, and respectively correspond to the two gradient fields generated by the two sets of gradient coils 120 to form two scanning fields of view in the uniform region 112.

[0055] In one embodiment, two sets of radio frequency coils 130 and one set of gradient coils 120 are arranged at intervals in the magnet bore. That is to say, the two sets of radio frequency coils 130 generate two radio frequency fields, and the gradient field generated by the gradient coils 120 can completely cover the two radio frequency fields, so that the two radio frequency fields form two scanning fields of view in the uniform region.

[0056] In one embodiment, the gradient field of the gradient coils 120 and the radio frequency field of the radio frequency coils 130 cooperate with the main magnetic field of the uniform region 112 in each scanning field of view and can be used for imaging.

[0057] SeeFigures 1 to 4 , in one embodiment, the superconducting magnet 110 includes a cryostat and a main coil 111 disposed in the cryostat. The cryostat is a multi-layer container structure, including an outer container, an inner container, and a shielding layer. The outer container has a through hole formed along the cavity and surrounding to extend axially, and this through hole is the magnet hole. The inner container is disposed in the cavity, and the shielding layer is disposed between the inner container and the outer container.

[0058] The inner container is surrounded by the shielding layer and is a hollow and closed cylindrical structure. Liquid helium is contained in the inner container, and a superconducting magnetic coil is also placed in the inner container. The main coil 111 is immersed in liquid helium to cool the main coil 111, reduce the temperature of the main coil 111, and ensure that the superconducting magnet 110 can work reliably. Of course, in other embodiments of the present invention, cooling pipes may also be provided on the outer periphery of the superconducting magnet 110, and a coolant is introduced into the cooling pipes to cool the superconducting magnet 110. The shielding layer can shield the heat radiated to the inner container, reduce the heat leakage of the inner container, so as to achieve the purpose of reducing the evaporation and loss of liquid helium.

[0059] The interlayer space between the outer wall of the inner container and the inner wall of the outer container is set as a vacuum environment to reduce the heat convection from the outside to the inner container. At the same time, a shielding layer is provided in this installation space to reduce the heat radiation to the inner container, thereby reducing the heat conduction from the external environment to the inner container.

[0060] The outer container is a hollow and closed cylindrical structure, and the shielding layer is disposed in the outer container. Moreover, the outer container, the inner container, and the shielding layer are coaxially arranged. The outer container protects the inner container and the shielding layer, reduces the heat conduction from the external environment to the inner container, reduces the evaporation amount of the liquid helium in the inner container, and ensures that the liquid helium can reliably cool the main coil 111.

[0061] See Figure 1 and Figure 4 , in one embodiment, the number and / or size of the uniform regions 112 of the superconducting magnet 110 are adjusted by optimizing the number and / or position of the main coil 111 in the superconducting magnet 110. That is to say, the number and size of the uniform regions 112 of the superconducting magnet 110 can be realized by optimizing the main coil 111, so that the uniform regions 112 can accommodate at least two scan fields of view.

[0062] The superconducting magnet 110 may include multiple sets of main coils, and each set of main coils has main coil units with different sizes along the radial direction of the magnet bore. In one embodiment, the main coils of the superconducting magnet 110 include a plurality of main coil units, which surround to form the magnet bore, and two sets of coaxially arranged main coils are formed by the plurality of main coil units with respect to the center of the magnet bore. Each set of main coils may include two or more main coil units with different sizes along the radial direction of the magnet bore, and the plurality of main coil units belonging to the same set of main coils are arranged in a stepped manner. In order to prevent the main magnetic field generated by the main coil units from being interfered by external electromagnetic waves, shield coil units may be inserted at adjacent positions of the plurality of main coil units.

[0063] To facilitate the description of the influence of the positions of the coils in the main coil 111 on the number and size of the uniform regions 112, an example is added here for description. However, the number and size of the uniform regions 112 are not limited to the positions of the coils in this example, and may also be other coil positions.

[0064] As Figure 5 shown, Figure 5 It is a schematic diagram of a set of main coils according to an embodiment of the present application. The horizontal axis represents the coordinate along the axial direction of the magnet bore, and the vertical axis represents the coordinate along the radial direction of the magnet bore. This set of main coils forms a magnet bore with a central aperture of 0.9 m. Another set of main coils is also distributed symmetrically with respect to this set of main coils, and the two cooperate to form a superconducting magnet 110 with an axial length of 2 m. This set of main coils includes six main coil units such as C2, C4 - C8, and C1 and C3 are shield coil units. Among them, the six main coil units C2, C4 - C8 are respectively arranged at different positions along the radial direction of the magnet bore and are arranged in a stepped manner. C3 is arranged at the middle position of the main coil units, and C1 is arranged outside each main coil unit.

[0065] During the excitation process, the current directions of the six main coil units C2, C4 - C8 are the same, and the current directions of the two shield coil units C1 and C3 are the same and opposite to the current directions of C2, C4 - C8. The six main coil units C2, C4 - C8 have different coordinates along the radial direction of the magnet bore, and the main coil unit C2 (the first main coil unit) at the end of the magnet bore has a larger size along the radial direction of the magnet bore relative to the main coil units C7, C8 (the second main coil unit) in the central region of the magnet bore. In this embodiment, the eight coil units C1 - C8 are coaxially arranged along the axial direction of the magnet bore.

[0066] In the embodiment of the present application, two symmetric uniform regions are generated on both sides with a relative central distance of 0.35 m. In the sphere region of 0.4 m in this uniform region, the pk - pk uniformity is 19 ppm; in the sphere region of 0.3 m, the pk - pk uniformity is 6 ppm, and this uniform region can be used to form an imaging field of view.

[0067] In this embodiment, the spacing L along the axial direction of the magnet hole between C5 and C6 56 is less than the spacing L along the axial direction of the magnet hole between C2 and C4 24 , that is, the adjacent main coil units located in the uniform region have a smaller spacing relative to the adjacent main coil units located in the non-uniform region.

[0068] Figure 5 For the coordinate relationships of the positions of the respective coil units of the superconducting magnet in , see the following table. In the table, a is the ordinate and z is the abscissa. The difference between two abscissas is the width of the coil, and the difference between two ordinates is the height of the coil.

[0069] C a1 a2 z1 z2 C 1 0.850196 0.864544 0.5834794 0.822623 C 2 0.482491 0.59606 0.9451404 0.990568 C 3 0.49714 0.52162 0.8407204 0.92208 C 4 0.517215 0.53905 0.6752086 0.76255 C 5 0.519606 0.54135 0.499499 0.553858 C 6 0.511569 0.523671 0.3233218 0.403998 C 7 0.50401 0.51375 0.1400974 0.237504 C 8 0.495555 0.508005 0.00847 0.045246

[0070] Compared with the current superconducting magnet, the number of main coils 111 in the superconducting magnet 110 of the present invention increases, the size of the magnet increases, and correspondingly, the cost of the magnet also increases.

[0071] In other embodiments of the present invention, by optimizing the number and positions of the main coils 111, a larger uniform region 112 is formed in the magnet hole, so that the uniform region 112 can also accommodate at least two fields of view.

[0072] See Figure 4 , in one embodiment, the number of the uniform regions 112 is one, and the range of the uniform region 112 is greater than or equal to the range of at least two fields of view. That is to say, the main coils 111 generate a single uniform region 112 near the geometric center of the superconducting magnet 110, but this uniform region 112 has a certain axial dimension and radial dimension, that is, the main coils 111 generate a larger uniform region 112 in the magnet hole. A larger uniform region 112 can simultaneously accommodate at least two fields of view, so as to realize parallel scanning of the imaging part and improve the scanning speed and resolution. It can be understood that in this embodiment, a larger uniform region 112 can cover at least two smaller uniform regions 112 in the following embodiments.

[0073] See Figures 1 to 3, in one embodiment, the number of the uniform regions 112 is at least two. The at least two uniform regions 112 are arranged at intervals along the axial direction of the magnet bore, and each uniform region 112 corresponds to the radio frequency field of a radio frequency coil 130. That is to say, by optimizing the number and position of the main coils 111 in the superconducting magnet 110, at least two axially arranged uniform regions 112 can be formed in the magnet bore. Each uniform region 112 accommodates at least one field of view. Moreover, each uniform region 112 corresponds to the radio frequency field of a radio frequency coil 130 and the gradient field of a gradient coil 120. In this way, the magnetic resonance device 100 can perform scanning imaging on at least two imaging parts of the scanning object 200 through the cooperation of the gradient coil 120 and the radio frequency coil 130 in the uniform region 112 of the magnet bore.

[0074] It can be understood that after the main coils 111 generate at least two uniform regions 112 in the magnet bore, the size of a single uniform region 112 is reduced compared with the current uniform region. However, the overall size of the at least two uniform regions 112 is much larger than the size of the current uniform region to accommodate at least two fields of view and realize simultaneous scanning imaging of at least two imaging parts.

[0075] Optionally, the uniform regions 112 can be arranged at intervals. That is to say, there is a certain distance between adjacent uniform regions 112. Of course, in other embodiments of the present invention, two adjacent uniform regions 112 can be arranged in a fitting manner. Further, the shape of the uniform region 112 is circular or elliptical.

[0076] In one embodiment, the distance between two adjacent uniform regions 112 is 0.1 to 5 times the axial length of the uniform region 112. It can be understood that the distance between two adjacent uniform regions 112 cannot be too large. If the distance between two adjacent uniform regions 112 is too large, the axial size of the superconducting magnet 110 will increase. Therefore, when the distance between two adjacent uniform regions 112 is 0.1 to 5 times the axial length of the uniform region 112, the imaging performance in the uniform region 112 can be guaranteed, and at the same time, the axial size of the superconducting magnet 110 can be reduced.

[0077] Further, the uniform region 112 is arranged in an elliptical shape. This can reduce the radial size of the magnet bore, and further reduce the radial size of the superconducting magnet 110, making the overall volume of the magnetic resonance device 100 small, which is beneficial to the miniaturization design of the magnetic resonance device 100 and can also reduce the cost.

[0078] In one embodiment, the uniform region 112 is symmetrically distributed about the center of the superconducting magnet 110; alternatively, the uniform region 112 is asymmetrically distributed about the center of the superconducting magnet 110. When the number of uniform regions 112 is one, the center of the uniform region 112 is located on the vertical axis of the superconducting magnet 110, that is, the uniform region 112 is symmetric about the vertical axis of the superconducting magnet 110, and the uniform region 112 is symmetrically distributed about the center of the superconducting magnet 110. Here, the vertical axis is the central axis of the superconducting magnet 110 in the vertical direction. Of course, the center of the uniform region 112 may also deviate from the vertical axis of the superconducting magnet 110, that is, the uniform region 112 is asymmetric about the vertical axis of the superconducting magnet 110, that is, the uniform region 112 is asymmetrically distributed about the center of the superconducting magnet 110.

[0079] When the number of uniform regions 112 is at least two, taking the number of uniform regions 112 being two as an example for illustration. The two uniform regions 112 are respectively located on both sides of the vertical axis of the superconducting magnet 110. The two uniform regions 112 may be symmetric about the vertical axis or asymmetric about the vertical axis. When the number of uniform regions 112 is three, one of the uniform regions 112 is located in the middle position, and the other two uniform regions 112 are located on both sides of the middle uniform region 112. The three uniform regions 112 may be symmetric on the vertical axis or asymmetric. When the number of uniform regions 112 is more, the principle is substantially the same as the above arrangement of the uniform regions 112, and will not be elaborated one by one here.

[0080] Optionally, the magnetic resonance device 100 further includes a controller, and the controller is electrically connected to the gradient coil 120, the radio frequency coil 130, etc. respectively. The controller can control at least two gradient coils 120 and at least two radio frequency coils 130 respectively, so as to perform scanning imaging on at least two imaging parts of the scanned object 200 located in the uniform region 112, that is, the magnetic resonance device 100 obtains at least two independent scan fields of view. In this way, within a unit time, the magnetic resonance device 100 can scan at least two imaging parts simultaneously, and the scanning speed is at least twice that of a conventional system.

[0081] See Figure 1 and Figure 3 In one embodiment, each radio frequency coil 130 includes a transmitting coil 131 and a receiving coil 132. The receiving coil 132 is arranged inside the gradient coil 120, and the transmitting coil 131 is located between the gradient coil 120 and the receiving coil 132. Each transmitting coil 131 forms a radio frequency field. The transmitting coil 131 is located inside the gradient coil 120, and the receiving coil 132 is located inside the transmitting coil 131. The transmitting coil 131 is used to transmit magnetic resonance signals, and the receiving coil 132 is used to receive the magnetic resonance signals passing through the scanned object 200 to achieve scanning imaging of the imaging part.

[0082] When the number of radio frequency coils 130 is at least two, the number of transmitting coils 131 is at least two, and the number of receiving coils 132 is also at least two. Moreover, at least two transmitting coils 131 are arranged along the axial direction of the magnet bore, and at least two receiving coils 132 are arranged along the axial direction of the magnet bore. In addition, the receiving coils 132, the transmitting coils 131, the gradient coils 120, and the superconducting magnet 110 are sleeved layer by layer in the radial direction, with the receiving coils 132 located in the innermost layer and the superconducting magnet 110 located in the outermost layer.

[0083] See Figure 1 and Figure 3 , in one embodiment, among two adjacent radio frequency coils 130, the two transmitting coils 131 are of an integral structure, or the two transmitting coils 131 are arranged at intervals. Optionally, two adjacent transmitting coils 131 are of an integral structure, that is, two adjacent transmitting coils 131 form a whole, and the axial length of two adjacent transmitting coils 131 corresponds to at least two gradient coils 120 and at least two receiving coils 132. Of course, in other embodiments of the present invention, at least two transmitting coils 131 may also be arranged at intervals. That is to say, two adjacent transmitting coils 131 are independent components, and there is a certain distance between them in the axial direction.

[0084] It should be noted that both of these layout methods of the transmitting coils 131 can correspond to the uniform region 112 generated by the main coil 111, match at least two scanning fields of view, realize simultaneous scanning and imaging of at least two imaging parts, and improve the scanning speed and efficiency.

[0085] See Figure 1 and Figure 3 , in one embodiment, among two adjacent radio frequency coils 130, the two receiving coils 132 are of an integral structure, or the two receiving coils 132 are arranged at intervals. Optionally, two adjacent receiving coils 132 are of an integral structure, that is, two adjacent receiving coils 132 form a whole, and the axial length of two adjacent receiving coils 132 corresponds to at least two gradient coils 120 and at least two transmitting coils 131. Of course, in other embodiments of the present invention, at least two receiving coils 132 may also be arranged at intervals. That is to say, two adjacent receiving coils 132 are independent components, and there is a certain distance between them in the axial direction.

[0086] It should be noted that both of these layout methods of the transmitting coils 131 can correspond to the uniform region 112 generated by the main coil 111, match at least two scanning fields of view, realize simultaneous scanning and imaging of at least two imaging parts, and improve the scanning speed and efficiency.

[0087] See Figure 1 and Figure 3, in one embodiment, in each radio frequency coil 130, the receiving coil 132 and the transmitting coil 131 are of an integral structure, or the receiving coil 132 and the transmitting coil 131 are separately arranged. Optionally, the receiving coil 132 and the transmitting coil 131 of the same radio frequency coil 130 are of an integral structure. That is to say, the transmitting coil 131 and the receiving coil 132 of the same radio frequency coil 130 are integrated into one body. Of course, in other embodiments of the present invention, the receiving coil 132 and the transmitting coil 131 of the same radio frequency coil 130 may also be separately arranged, and the two are two independent components.

[0088] It can be understood that whether the transmitting coils 131 and the receiving coils 132 of at least two radio frequency coils 130 are integrally arranged or separately arranged, they can both correspond to the uniform region 112 generated by the main coil 111, match at least two scanning fields of view, and realize simultaneous scanning and imaging of at least two imaging parts, thereby improving the scanning speed and efficiency.

[0089] See Figure 1 and Figure 3 , in one embodiment, two adjacent gradient coils 120 are of an integral structure, or two adjacent gradient coils 120 are spaced apart. Optionally, at least two gradient coils 120 may also be spaced apart. That is to say, two adjacent gradient coils 120 are independent components, and there is a certain distance between the two in the axial direction. In this way, different scanning parameters and sequences can be selected for at least two imaging parts according to the different tissue characteristics of the imaging parts, thus providing more possibilities for the application of magnetic resonance.

[0090] Of course, in other embodiments of the present invention, two adjacent gradient coils 120 are of an integral structure. That is to say, two adjacent gradient coils 120 form a whole, and the axial lengths of two adjacent gradient coils 120 correspond to at least two receiving coils 132 and at least two transmitting coils 131. When the linearly uniform part of the gradient coil 120 is large enough, a single gradient coil 120 can also be used in cooperation with the uniform region 112. However, in this way, it is impossible to separately select the tissues of the imaging parts, but it is also possible to realize simultaneous scanning and imaging of at least two parts without moving the scanning bed, which can also improve the scanning speed and efficiency.

[0091] It should be noted that both of these layout methods of the transmitting coil 131 can correspond to the uniform region 112 generated by the main coil 111, match at least two scanning fields of view, realize simultaneous scanning and imaging of at least two imaging parts, and improve the scanning speed and efficiency.

[0092] See Figures 1 to 4, in a specific embodiment, the uniform region 112 of the main coil 111 of the superconducting magnet 110 corresponds to two fields of view. The number of radio frequency coils 130 is two, and the number of gradient coils 120 is also two. Each radio frequency coil 130 corresponds to one gradient coil 120, and each radio frequency coil 130 matches one field of view. That is to say, the magnetic resonance device 100 can simultaneously scan and image two imaging parts of the scanning object 200. Compared with the current single field of view, the scanning speed is increased by at least two times.

[0093] In this specific embodiment, the number of both the radio frequency coils 130 and the gradient coils 120 is two to match two fields of view. Of course, in other embodiments of the present invention, the number of the radio frequency coils 130 and the gradient coils 120 can also be three or more. The present invention only takes the number of the radio frequency coils 130 and the gradient coils 120 being two as an example for illustration. The principle when the number of the radio frequency coils 130 and the gradient coils 120 is more is substantially the same as that when the number is two, but only the overall size and cost will increase, which will not be elaborated one by one here.

[0094] In this specific embodiment, the number of the uniform regions 112 formed by the main coil 111 can be one or two. Moreover, the layout forms of the gradient coils 120, the transmitting coil 131 and the receiving coil 132 in the radio frequency coils 130 can also be adjusted accordingly. The following will elaborate on various different situations in detail.

[0095] In the first embodiment of the present invention, as Figure 1 shown, the main coil 111 of the superconducting magnet 110 forms two uniform regions 112. Each uniform region 112 corresponds to one field of view. The number of radio frequency coils 130 is two, and the number of gradient coils 120 is two. Each radio frequency coil 130 is arranged corresponding to one uniform region 112. And, in this embodiment, the transmitting coils 131 in two adjacent radio frequency coils 130 are arranged at intervals, corresponding to the two uniform regions 112 respectively. The two receiving coils 132 are arranged at intervals, corresponding to the two uniform regions 112 respectively. The two gradient coils 120 are arranged at intervals, corresponding to the two uniform regions 112 respectively.

[0096] To better illustrate the size of the uniform region 112, the difference in the uniform region of the magnetic resonance device 100 of the present invention compared to the current magnetic resonance device is now described using a magnet bore with a 90 cm aperture. In the current magnetic resonance device, on a 1.5 T superconducting magnet with a 90 cm aperture, the uniform region is usually a sphere with a diameter of 50 cm. After adopting the above solution, while maintaining the 90 cm aperture, the main coil 111 is optimized, and two uniform regions 112 in the shape of spheres with a diameter of 40 cm can be obtained. Generally, the central axial gap between the two uniform regions 112 is not less than 40 cm, and the sum of the axial lengths of the two uniform regions 112 is 80 cm. Obviously, the spatial size of a single uniform region 112 is reduced, but the number and total size of the uniform regions 112 are much larger than those of the uniform region of the current superconducting magnet.

[0097] The controller of the magnetic resonance device 100 can separately control the two gradient coils 120, the two radio frequency coils 130, etc., to achieve separate scanning and imaging of the imaging parts of the scanned object 200 located in the two uniform regions 112, that is, the magnetic resonance device 100 obtains two independent scanning fields of view. In this way, within a unit time, the magnetic resonance device 100 can simultaneously scan two imaging parts, and the scanning speed is at least twice that of a conventional system. In addition, different scanning parameters and sequences can be selected for the two imaging parts according to the different tissue characteristics of the imaging parts, thus providing more possibilities for the application of magnetic resonance.

[0098] In the third embodiment of the present invention, as Figure 4 shown, the main coil 111 of the superconducting magnet 110 forms a uniform region 112. The size of this uniform region 112 is relatively large, and it can respectively correspond to the two gradient coils 120 and the two radio frequency coils 130. Moreover, this uniform region 112 can match two scanning fields of view. And in this embodiment, the transmitting coils 131 in two adjacent radio frequency coils 130 are arranged at intervals, corresponding to the two uniform regions 112 respectively, the two receiving coils 132 are arranged at intervals, corresponding to the two uniform regions 112 respectively, and the two gradient coils 120 are arranged at intervals, corresponding to the two uniform regions 112 respectively.

[0099] The magnetic resonance device 100 of the present invention generates a uniform region 112 capable of matching at least two scanning fields of view through the main coil 111 in the superconducting magnet 110, simultaneously scans and images at least two parts of the scanned object 200, obtains image information of at least two imaging parts, improves the scanning speed and efficiency, and is convenient to use.

[0100] The present invention also provides a control method for a magnetic resonance device 100. The magnetic resonance device 100 includes a superconducting magnet 110, gradient coils 120, and a radio frequency coil 130. The superconducting magnet 110 includes multiple groups of main coils 111 arranged coaxially. The multiple groups of main coils 111 form a magnet bore, and each group of main coils 111 includes two main coils 111 having different sizes along the radial direction of the magnet bore. The gradient coils 120 and the radio frequency coil 130 are disposed in the magnet bore;

[0101] The control method includes:

[0102] Exciting multiple groups of the main coils 111 to generate a uniform magnetic field region in the magnet bore, and the uniform magnetic field region covers a first region and a second region;

[0103] Driving the radio frequency coil 130 to generate a first radio frequency field in the first region and a second radio frequency field in the second region at the same time; driving the gradient coils 120 to generate a first gradient field in the first region and a second gradient field in the second region at the same time;

[0104] Alternatively, driving the radio frequency coil 130 to generate a first radio frequency field in the first region during a first time period and a second radio frequency field in the second region during a second time period; driving the gradient coils 120 to generate a first gradient field in the first region during the first time period and a second gradient field in the second region during the second time period.

[0105] When the magnetic resonance device 100 simultaneously images multiple imaging parts, the magnetic resonance device 100 excites multiple groups of main coils 111 and generates a uniform magnetic field region in the magnet bore, so that the uniform magnetic field region covers the first region and the second region. Then, driving the radio frequency coil 130 to generate a first radio frequency field in the first region and a second radio frequency field in the second region at the same time; then driving the gradient coils 120 to generate a first gradient field in the first region and a second gradient field in the second region at the same time. At this time, two scan fields of view are formed in the first region and the second region of the magnet bore, and two imaging parts can be imaged simultaneously.

[0106] Of course, after the magnetic resonance device 100 excites the main coils 111, the radio frequency coil 130 can also be driven to generate a first radio frequency field in the first region during a first time period and a second radio frequency field in the second region during a second time period; driving the gradient coils 120 to generate a first gradient field in the first region during the first time period and a second gradient field in the second region during the second time period. At this time, two scan fields of view are formed in the first region and the second region of the magnet bore, and two imaging parts can be imaged simultaneously.

[0107] In an embodiment, the magnetic resonance device 100 further includes a scanning bed, and the control method further includes:

[0108] In a first time period, drive the scanning bed to the first area to perform imaging of a first scanning field of view;

[0109] In a second time period, drive the scanning bed to the second area to perform imaging of a second scanning field of view.

[0110] In one embodiment, the control method may include: driving the scanning bed into the first area and the second area, with a part of the scanning bed in the first area and another part of the scanning bed in the second area, and simultaneously performing imaging of the first scanning field of view and the second scanning field of view.

[0111] When imaging a scanning object 200, the scanning object 200 is located on the scanning bed, and the scanning bed is controlled to enter or exit the first area or the second area. When the scanning bed drives the scanning object 200 into the first area or the second area, a scanning operation can be performed through the scanning field of view of the corresponding area to achieve scanning imaging of the imaging part.

[0112] In one embodiment, the magnetic resonance device 100 includes a multi-core driver, which includes a multi-core pulse sequence generator, a transmitting coil, a radio frequency amplification system, etc., and is used to drive the radio frequency coil to generate radio frequency pulse signals with multiple different frequencies, so as to obtain magnetic resonance signals of the tissue under test under multiple types of atomic nuclei. Among them, the multi-core pulse sequence generator is used to generate the required radio frequency pulses, change the radio frequency phase and trigger sampling, and precisely control the working timing between the various components in the multi-core radio frequency generation system; the transmitting coil is used to generate radio frequency pulse signals in multiple different Larmor frequency bands, and the radio frequency pulse signals are amplified by the radio frequency amplifier to obtain high-energy radio frequency pulse signals, and act on the tissue organs of the detection object to obtain nuclear magnetic resonance signals. In this embodiment, a transmitting coil 131 for generating a first radio frequency pulse may be provided in the first area, and a transmitting coil 131 for generating a second radio frequency pulse may be provided in the second area, and the transmitting coils 131 in the two areas are simultaneously connected to the multi-core pulse sequence generator. Correspondingly, the control method includes: generating a first pulse with a frequency corresponding to the first type of atomic nucleus in the first area; generating a second pulse with a frequency corresponding to the second type of atomic nucleus in the second area; simultaneously receiving a first magnetic resonance signal excited by the first type of atomic nucleus and a second magnetic resonance signal excited by the second type of atomic nucleus; generating multi-type magnetic resonance images corresponding to multi-type atomic nuclei according to the first magnetic resonance signal and the second magnetic resonance signal. In the embodiment of the present application, multi-nuclear magnetic resonance imaging can be realized simultaneously.

[0113] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0114] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A magnetic resonance device, characterized in that, Comprising: A superconducting magnet having a main coil therein, the main coil forming a magnet bore, and the main coil being capable of generating at least two uniform regions within the magnet bore, the at least two uniform regions being spaced apart along the axial direction of the magnet bore; At least one set of gradient coils disposed in the magnet bore along the axial direction; And At least two radio frequency coils disposed in the magnet bore along the axial direction and cooperating with at least one set of the gradient coils, the at least two radio frequency coils being capable of forming at least two radio frequency fields; The at least two uniform regions cooperate with the at least two radio frequency fields such that the magnetic resonance device has at least two scan fields of view, wherein the at least two scan fields of view are spaced apart along the axial direction of the magnet bore to enable simultaneous imaging of at least two scan sites.

2. The magnetic resonance device according to claim 1, characterized in that, Two sets of the gradient coils and two sets of the radio frequency coils are respectively disposed in the magnet bore at intervals; Alternatively, two sets of the radio frequency coils and one set of the gradient coils are disposed in the magnet bore at intervals.

3. The magnetic resonance device according to claim 1, characterized in that, A plurality of the uniform regions are spaced apart along the axial direction of the magnet bore, and the distance between two adjacent uniform regions is 0.1 to 5 times the axial length of the uniform region.

4. The magnetic resonance device according to claim 3, characterized in that The uniform regions are symmetrically distributed about the center of the superconducting magnet; or, the uniform regions are asymmetrically distributed about the center of the superconducting magnet.

5. The magnetic resonance device according to claim 1, characterized in that, The main coil of the superconducting magnet forms two of the uniform regions, each uniform region corresponding to one of the scan fields of view, and one set of gradient coils and one set of radio frequency coils are respectively disposed in each uniform region.

6. The magnetic resonance device according to claim 5, characterized in that, Two of the gradient coils corresponding to different uniform field regions are of an integral structure, or two of the gradient coils corresponding to different uniform field regions are spaced apart.

7. The magnetic resonance device according to claim 5, characterized in that, The main coil includes a first main coil and a second main coil, the first main coil is located at an end of the magnet bore, the second main coil is located in a central region of the magnet bore, and the size of the first main coil along the radial direction of the magnet bore is greater than the size of the second main coil along the radial direction of the magnet bore.

8. A control method for a magnetic resonance device, characterized in that, The magnetic resonance device includes a superconducting magnet, gradient coils, and radio frequency coils, the superconducting magnet includes multiple sets of main coils disposed along the axial direction, the multiple sets of main coils form a magnet bore, and the gradient coils and the radio frequency coils are disposed in the magnet bore; The control method includes: Exciting multiple sets of the main coils to generate a uniform field region within the magnet bore, the uniform field region covering a first region and a second region; Driving the radio frequency coils to generate a first radio frequency field in the first region and a second radio frequency field in the second region simultaneously; driving the gradient coils to generate a first gradient field in the first region and a second gradient field in the second region simultaneously; Or, driving the radio frequency coils to generate a first radio frequency field in the first region during a first time period and a second radio frequency field in the second region during a second time period; driving the gradient coils to generate a first gradient field in the first region during a first time period and a second gradient field in the second region during a second time period.

9. The control method of the magnetic resonance device according to claim 8, characterized in that, The magnetic resonance device further includes a scan bed, and the control method further includes: During a first time period, driving the scan bed to the first region to perform imaging of a first scan field of view; In the second time period, drive the scanning bed to the second area to perform imaging of the second scanning field of view; Alternatively, drive the scanning bed into the first area and the second area, and perform imaging of the first scanning field of view and imaging of the second scanning field of view.

Images