Magnetic Resonance Guided Radiotherapy System and Magnetic Resonance Equipment

Abstract

The present invention provides a magnetic resonance-guided radiotherapy system and a magnetic resonance device. The magnetic resonance-guided radiotherapy system includes a magnetic resonance component and a radiotherapy component. The superconducting magnet has a through hole extending axially. The gradient coil and the radio frequency coil are sequentially arranged in the through hole from outside to inside. The inner wall of the through hole of the superconducting magnet is provided with a first groove extending circumferentially. Since the radiotherapy component is arranged in the first groove, the rays emitted by the treatment head only need to pass through the gradient coil and the radio frequency coil to reach the patient, and there are fewer obstacles on the ray path, so that less metal material is penetrated, the attenuation of the rays is smaller, and the treatment efficiency is high. The superconducting magnet is an integral type, not a split type, and its coil design, cooling system and control system can adopt conventional methods, so as to effectively control the system cost and ensure the uniformity and stability of the main magnetic field.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a magnetic resonance-guided radiotherapy system and a magnetic resonance device. Background Art

[0002] Radiotherapy (RT) is an important local treatment method for malignant tumors. A medical linear accelerator is a large medical device used for cancer radiotherapy. It generates X-rays and electron beams to directly irradiate tumors in a patient's body, thereby achieving the purpose of eliminating or reducing tumors.

[0003] Conventional radiotherapy usually requires two or more localizations on other imaging devices (such as B-ultrasound, CT, or magnetic resonance MR) to determine the tumor location, and then the patient can enter the radiotherapy device for treatment. This localization method takes a long time and cannot perform real-time imaging during the treatment process, resulting in low treatment accuracy and inability to accurately treat the disease.

[0004] An integrated image-guided radiotherapy device is an important means to achieve accurate treatment, such as a magnetic resonance-guided radiotherapy system, which is an integrated device of a magnetic resonance device (MR) and a linear accelerator (LINAC). Compared with a CT-guided radiotherapy device, the MR-LINAC device has a small radiation dose and high imaging resolution for soft tissue structures.

[0005] In the prior art, magnetic resonance-guided radiotherapy systems are generally divided into two categories. One is an open magnetic resonance-guided linear accelerator system, and the other is a traditional superconducting magnetic resonance-guided linear accelerator system.

[0006] As Figure 1 shown, an open magnetic resonance-guided linear accelerator system usually adopts a split magnet 1. The magnet 1 is disconnected along the axial direction and is divided into two parts, left and right or up and down, with a gap 2 formed in the middle. The gap 2 is used to accommodate the rotating gantry 3 and the radiotherapy treatment head 4, so that the rays of the linear accelerator system can pass through the gap 2 and irradiate the patient. This split magnet structure is expensive, has a complex manufacturing process, and the two separated parts of the magnet need to be controlled separately, resulting in low uniformity and stability of the main magnetic field.

[0007] As Figure 2As shown in the figure, in a traditional superconducting magnetic resonance-guided linear accelerator system, a rotating gantry 3 and a radiotherapy treatment head 4 of the linear accelerator are arranged outside the magnet 1. Then, the radiotherapy rays need to pass through many components such as the cryostat, superconducting coils, and coil skeletons of the magnet 1 before irradiating the patient. As a result, the ray attenuation is serious and the treatment efficiency is low. Moreover, the size of this system is large, and the treatment head is far from the patient, further resulting in a smaller effective dose reaching the patient, thus affecting its treatment accuracy and treatment effect. In addition, the direct irradiation of the radiotherapy rays on the superconducting coils may also cause the superconducting coils to quench and thus unable to work properly. Summary of the Invention

[0008] Based on this, in view of the problems of low main magnetic field uniformity and stability and low treatment efficiency existing in the traditional magnetic resonance-guided radiotherapy system, it is necessary to provide a magnetic resonance-guided radiotherapy system and a magnetic resonance device with higher main magnetic field uniformity and stability, less ray attenuation, and high treatment efficiency.

[0009] An embodiment of the present application provides a magnetic resonance-guided radiotherapy system, including:

[0010] A magnetic resonance component, including: a superconducting magnet, gradient coils, and radio frequency coils. The superconducting magnet is axially provided with a through hole. The gradient coils and the radio frequency coils are sequentially arranged inside the through hole from outside to inside. The inner wall surrounding the through hole is provided with a first groove extending in the circumferential direction; and

[0011] A radiotherapy component, arranged in the first groove; the radiotherapy component includes a gantry and a treatment head. The gantry extends along the same circumferential direction as the first groove, and the treatment head is installed on the gantry and can rotate circumferentially along the gantry.

[0012] The above magnetic resonance-guided radiotherapy system includes a magnetic resonance component and a radiotherapy component. The superconducting magnet is axially provided with a through hole. The gradient coils and the radio frequency coils are sequentially arranged inside the through hole from outside to inside. The inner wall surrounding the through hole is provided with a first groove extending in the circumferential direction. Since the radiotherapy component is arranged in the first groove, the rays emitted by the treatment head only need to pass through the gradient coils and the radio frequency coils to reach the patient. There are fewer obstacles on the ray path, so less metal material is penetrated, the ray attenuation is smaller, and the treatment efficiency is high. The superconducting magnet is integrated, not a split type, and its coil design, cooling system, and control system can adopt conventional methods, so as to effectively control the system cost and ensure the uniformity and stability of the main magnetic field.

[0013] In one embodiment, the superconducting magnet includes a superconducting coil assembly and a cryostat. The cryostat is used to accommodate the superconducting coil assembly. The housing of the cryostat has a first sidewall, and the first sidewall surrounds and forms the through hole; the superconducting coil assembly is wound around the first sidewall.

[0014] In one embodiment, the superconducting coil assembly includes a main coil skeleton and a main coil wound around the main coil skeleton. The main coil skeleton is wound around the first sidewall. The main coil skeleton is provided with a second groove corresponding to the first groove, and the second groove is used to avoid the structure of the first sidewall at the first groove.

[0015] In one embodiment, the main coil includes a first main coil portion, a second main coil portion, and a third main coil portion arranged in sequence along the axis. The position of the second main coil portion corresponds to the position of the second groove along the axis, and the position where the second main coil portion emits rays is axially offset from the position of the treatment head.

[0016] In one embodiment, the main coil includes a first main coil portion and a third main coil portion arranged in sequence along the axis. The first main coil portion and the third main coil portion are axially distributed on both sides of the second groove, and no coil is wound at the position on the main coil skeleton corresponding to the second groove.

[0017] In one embodiment, the superconducting coil assembly includes:

[0018] A main coil skeleton that surrounds the first sidewall. The main coil skeleton is axially separated into two parts, and the two parts are axially located on different sides of the first groove;

[0019] A main coil wound around the main coil skeleton;

[0020] A shielding coil skeleton located outside the main coil skeleton and fixedly connected to the main coil skeleton. The shielding coil skeleton is axially continuous; and

[0021] A shielding coil wound around the shielding coil skeleton.

[0022] In one embodiment, the radiotherapy assembly includes a shielding assembly that at least covers the treatment head.

[0023] The embodiments of the present application further provide a magnetic resonance device, including:

[0024] A cryostat provided with a through hole along the axis. At different positions along the axis of the through hole, the through hole has a first inner diameter and a second inner diameter, and the second inner diameter is greater than the first inner diameter;

[0025] The main coil structure is disposed inside the cryogenic vessel;

[0026] The main coil structure includes a main coil skeleton and a main coil wound around the main coil skeleton. The main coil skeleton includes a first main coil skeleton portion and a second main coil skeleton portion that are coaxially arranged along the axis of the cryogenic vessel. The inner diameter of the second main coil skeleton portion is greater than the inner diameter of the first main coil skeleton portion;

[0027] Along the axial direction of the cryogenic vessel, the position of the second main coil skeleton portion corresponds to the position of the through hole having the second inner diameter, and the position of the first main coil skeleton portion corresponds to the position of the through hole having the first inner diameter.

[0028] The through hole of the above-mentioned cryogenic vessel has a first inner diameter and a second inner diameter, and the second inner diameter is greater than the first inner diameter. The inner wall of the through hole forms a first groove extending circumferentially, which is beneficial for placing the radiotherapy component; the main coil skeleton of the main coil structure conforms to the inner diameter of the through hole and is set to have a first main coil skeleton portion and a second main coil skeleton portion with two different inner diameters. In this way, a special-shaped magnet architecture suitable for a magnetic resonance-guided radiotherapy system is formed, and the uniformity and stability of the main magnetic field can be ensured.

[0029] In one embodiment, the cryogenic vessel includes a first end and a second end that are oppositely arranged along the axial direction;

[0030] One of the two first main coil skeleton portions is disposed at a position adjacent to the first end, and the other is disposed at a position adjacent to the second end;

[0031] The second main coil skeleton portion is disposed between the two first main coil skeleton portions.

[0032] In one embodiment, it further includes: a radiotherapy component, which is accommodated in the through hole, and the radiotherapy component is located at the position where the through hole has the second inner diameter. Description of the Drawings

[0033] Figure 1 It is a schematic structural diagram of a magnetic resonance-guided radiotherapy system in the prior art;

[0034] Figure 2 It is a schematic structural diagram of another magnetic resonance-guided radiotherapy system in the prior art;

[0035] Figure 3 It is a schematic structural diagram of the magnetic resonance-guided radiotherapy system in the first embodiment of the present application;

[0036] Figure 4 For Figure 3 The longitudinal sectional view of the magnetic resonance-guided radiotherapy system in

[0037] Figure 5 A longitudinal sectional schematic view of a magnetic resonance-guided radiotherapy system of another embodiment;

[0038] Figure 6 is Figure 4 a partial structural schematic view of;

[0039] Figure 7 A partial longitudinal sectional schematic view of a magnetic resonance-guided radiotherapy system of yet another embodiment;

[0040] Figure 8 A structural schematic view of the magnetic resonance-guided radiotherapy system in the second embodiment of the present application. Detailed implementation manners

[0041] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following describes the detailed implementation manners of the present invention in conjunction with the accompanying drawings. Many specific details are set forth in the following description 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.

[0042] In the description of the present invention, it should be understood that 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. indicate the orientation or positional relationship 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 a limitation of the present invention.

[0043] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity 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" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0044] In the present invention, unless otherwise clearly defined or limited, terms such as "installed", "connected", "joined", "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 defined. 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.

[0045] In the present invention, unless otherwise clearly defined 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.

[0046] It should be noted that when an element is referred to as being "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.

[0047] Please refer to Figure 3 and Figure 4 According to the first embodiment of the present application, a magnetic resonance-guided radiotherapy system 100 is provided. The magnetic resonance-guided radiotherapy system 100 includes: a magnetic resonance component and a radiotherapy component 130. The magnetic resonance component includes a superconducting magnet, a gradient coil 110, and a radio frequency coil 120. The superconducting magnet forms a through hole 133 extending axially. The gradient coil 110 and the radio frequency coil 120 are sequentially arranged from the outside to the inside in the through hole, so as to form a nested structure with the superconducting magnet in the outermost layer, the gradient coil 110 in the middle layer, and the radio frequency coil 120 in the innermost layer. The inner wall surrounding the through hole 133 is provided with a first groove (not shown) extending circumferentially. The radiotherapy component 130 is disposed in the first groove. The radiotherapy component 130 includes a gantry 131 and a treatment head 132. The gantry 131 extends along the same circumference as the first groove. The treatment head 132 is mounted on the gantry 131 and can rotate circumferentially around the axis of the gantry 131.

[0048] Specifically, the coil hole of the radio frequency coil 120 forms an inspection channel for accommodating a patient. A superconducting magnet generally includes a superconducting coil assembly. The superconducting coil assembly includes a main coil skeleton 141 and a main coil 142 wound around the main coil skeleton 141. The main coil 142 forms a main magnet for generating a uniform strong magnetic field to cause the hydrogen protons in the patient's body to precess and generate a macroscopic longitudinal magnetization vector; the radio frequency coil 120 is used to emit radio frequency pulses to excite the macroscopic longitudinal magnetization vector of tissue protons; the gradient coil 110 is used to generate various gradient fields to enable the user to achieve the central position, thickness, and spatial positioning encoding within the excited acquisition slice.

[0049] The superconducting coil assembly further includes a shielding coil skeleton 143 and a shielding coil 144 wound around the shielding coil skeleton 143. The shielding coil 144 is disposed outside the main coil 142 and is used to shield the magnetic field outside the main coil 142. The main coil 142 and the shielding coil 144 are preferably made of superconducting coils, so that the superconducting coil assembly generates a superconducting current at low temperature to form a main magnetic field.

[0050] The superconducting magnet further includes a cryostat 150. The cryostat 150 is used to accommodate the superconducting coil assembly and provide a cryogenic environment for the superconducting coil assembly. The cryostat 150 has a first side wall 151 surrounding the gradient coil 110. The first side wall 151 encloses a through hole 133, and the first side wall 151 is provided with the above-mentioned first groove. The superconducting coil assembly surrounds the first side wall 151.

[0051] Specifically, as Figure 4 shown, a first groove is formed by radially recessing at the axial center region of the first side wall 151 forming the through hole. In this embodiment, the cryostat 150 further includes a second side wall 152 and a head 153. The second side wall 152 surrounds the first side wall 151. The two ends of the first side wall 151 and the second side wall 152 are respectively connected to the head 153. The second side wall 152, the first side wall 151, and the head 153 together enclose a cooling cavity 102. The superconducting coil assembly is located in the cooling cavity 102 and between the first side wall 151 and the second side wall 152. A refrigeration system can be provided in the cooling cavity 102 to provide a cryogenic environment through the refrigeration system. The refrigeration system can adopt the refrigeration systems in the prior art and will not be elaborated here.

[0052] The frame 131 is disposed in the first groove and corresponds to the shape of the first groove. The first groove can be a groove extending along an arc or can form an annular groove. For example, when the first groove is an annular groove, the frame 131 is an annular frame. The first groove can also be semi-annular, and the frame 131 is a semi-annular frame. The axis of the frame 131 substantially coincides with the axis of the first groove or there may be a slight deviation caused by installation errors, etc.

[0053] Since the first groove is provided on the first side wall 151, the frame 131 can be fixedly connected to the first side wall 151, and thus the frame 131 can be installed in the first groove.

[0054] The treatment head 132, as a radiation source for radiotherapy, generally includes components such as a linear accelerator, a target, and a collimator. The linear accelerator is used to accelerate electrons to generate an electron beam. The target can receive the accelerated charged particles or ions to generate a radiation beam for radiotherapy. The collimator is used to control the shape of the photon beam for radiotherapy. The specific structure and connection structure of the treatment head 132 and the frame 131 can adopt the existing technology and will not be elaborated here.

[0055] When the treatment head 132 rotates around the axis of the frame 131, it simultaneously rotates independently relative to the superconducting magnet. Since the gradient coil 110 and the radio frequency coil 120 are both arranged in the through hole 133, and the radiotherapy assembly 130 is arranged in the first groove on the inner wall surrounding the through hole 133, the rays emitted by the treatment head 132 can pass through the gradient coil 110 and the radio frequency coil 120 to reach the patient. Since the patient is located in the examination channel formed by the coil hole of the radio frequency coil 120 during radiotherapy, the patient is not only within the radiation field of the treatment head 132 but also within the imaging area of the magnetic resonance assembly. Thus, real-time imaging of the treatment site can be performed using the magnetic resonance assembly while radiotherapy is being carried out, achieving more accurate lesion localization. Especially for parts that move with breathing, accurate treatment can be achieved, and the treatment situation of the lesion site can be observed in real time, so as to judge whether it is necessary to change the treatment plan according to the treatment situation.

[0056] The above-mentioned magnetic resonance-guided radiotherapy system 100 includes a magnetic resonance assembly and a radiotherapy assembly 130. The superconducting magnet is provided with a through hole 133 extending axially. The gradient coil 110 and the radio frequency coil 120 are sequentially arranged from outside to inside in the through hole 133. The inner wall surrounding the through hole is provided with a first groove extending circumferentially. Since the radiotherapy assembly 130 is arranged in the first groove, the rays emitted by the treatment head 132 only need to pass through the gradient coil 110 and the radio frequency coil 120 to reach the patient.

[0057] Compared with the traditional magnetic resonance-guided radiotherapy system 100 in the prior art, the magnetic resonance-guided radiotherapy system 100 of the present application does not need to pass through the cryostat 150, there are fewer obstacles on the ray path, so less metal material is penetrated, the attenuation of the rays is smaller, and the treatment efficiency is high.

[0058] Compared with the open magnetic resonance-guided radiotherapy system 100 in the prior art, the superconducting magnet of the magnetic resonance-guided radiotherapy system 100 of the present application is an integrated one, not a separated one. Its coil design, cooling system and control system can adopt conventional methods, thereby effectively controlling the system cost and ensuring the uniformity and stability of the main magnetic field.

[0059] In addition, since the first groove is provided on the inner wall surrounding the through hole 133, the treatment head 132 is located in the first groove, and the patient is located in the inspection channel formed by the through hole 133. Therefore, the technical solution of the present application shortens the distance between the treatment head 132 and the patient and the lesion, and reduces the overall size of the radiotherapy system.

[0060] It can be understood that in this embodiment, since the gantry 131 is arranged in the first groove, when the first groove is an annular groove and the gantry 131 is an annular gantry, the maximum range of the rotation angle of the treatment head 132 can be designed to be 360°, that is, the treatment head 132 can rotate relative to the superconducting magnet by a maximum of 360°. Compared with the traditional radiotherapy system, the magnetic resonance-guided radiotherapy system 100 of the present application can perform 360° all-round radiotherapy on the lesion site of the patient through the rotation of the treatment head 132 without the need to rotate the superconducting magnet and the gantry 131, and the rotation method is simple and easy to implement.

[0061] Optionally, the gantry 131 is a segmented structure divided into multiple segments along the circumferential direction, so that each segment of the gantry 131 can be assembled into the first groove separately, which is convenient for assembly.

[0062] Generally, the inner diameter of the through hole 133 of the superconducting magnet is generally 60 cm to 100 cm. The treatment head 132 can be flush with the inner wall of the through hole along the radial direction, which can shorten the distance between the treatment head 132 and the patient and the lesion, thereby shortening the overall size of the radiotherapy system and making the structure compact.

[0063] Specifically, the distance between the treatment head 132 and the axis of the superconducting magnet can be designed to be 30 to 60 cm. The ring width of the annular contour corresponding to the first groove is not less than 30 cm.

[0064] Please refer to Figure 4 , in an embodiment, the main coil skeleton 141 surrounds the first side wall 151. The main coil skeleton 141 is provided with a second groove 103 corresponding to the first groove, and the second groove 103 is used to avoid the structure of the first side wall 151 at the first groove.

[0065] Specifically, the second groove 103 corresponds to the first groove in the axial direction. The structure of the first side wall 151 at the first groove is located in the second groove 103, so that the main coil skeleton 141 can avoid the structure of the first side wall 151 at the first groove through the second groove 103.

[0066] The main coil 142 includes a first main coil portion 1421, a second main coil portion 1422, and a third main coil portion 1423 that are arranged axially in sequence. The position of the second main coil portion 1422 corresponds axially to the position of the second groove 103. As Figure 4 shown, the inner diameter of the second main coil portion 1422 is respectively larger than the inner diameters of the first main coil portion 1421 and the third main coil portion 1423. To improve the uniformity of the magnetic field formed by the main coil 142, the number of turns, the energizing current, etc. of the second main coil portion 1422 can be adjusted.

[0067] Corresponding to the first main coil portion 1421, the second main coil portion 1422, and the third main coil portion 1423 respectively, the main coil skeleton 141 can also be divided into three parts axially. When machining the main coil skeleton 141, these three parts of the main coil skeleton 141 can be machined separately by casting or machining, and then these three parts are welded, which is convenient for machining the main coil skeleton 141 to form an axially continuous main coil skeleton 141. In this embodiment, the first main coil portion 1421 and the third main coil portion 1423 are respectively located at both ends of the superconducting magnet, corresponding to both ends of the through hole 133; the second main coil portion 1422 is located in the central region or the middle region of the superconducting magnet, corresponding to the middle position of the through hole 133.

[0068] In one embodiment, the position where the second main coil portion 1422 emits rays is axially offset from the position where the treatment head 132 emits rays, so that the rays emitted by the treatment head 132 can be reduced or avoided from irradiating the second main coil portion 1422 on the opposite side as much as possible, thereby avoiding affecting the normal operation of the second main coil portion 1422 as much as possible.

[0069] Specifically, as Figure 4 shown, in this embodiment, the second main coil portion 1422 is axially divided into a first part 1422a and a second part 1422b. Along the axis of the superconducting magnet, the position where the treatment head 132 emits rays is located between the position of the first part 1422a and the position of the second part 1422b.

[0070] Please refer to Figure 5 , in another embodiment, the main coil 142 may also not be arranged at the position corresponding to the first groove, that is, the second main coil portion 1422 is not arranged, and only the first main coil portion 1421 and the third main coil portion 1423 are left, so that the irradiation of the rays on the main coil 142 can be further avoided and the stability of the magnetic field can be improved.

[0071] In addition, in some superconducting magnet structures, the main coil 142 can also be directly wound on the cryostat 150 without the main coil skeleton 141.

[0072] Please refer to Figure 4 , in one embodiment, the cryogenic container 150 includes an inner cooling layer 150a, an intermediate thermal shielding layer 150b, and an outer vacuum layer 150c that surround the superconducting coil assembly layer by layer from the inside out. The first groove is provided in the outer vacuum layer 150c. The intermediate thermal shielding layer 150b is provided with a third groove 104 corresponding to the first groove, and the third groove 104 is used to avoid the structure of the outer vacuum layer 150c at the first groove. The inner cooling layer 150a is provided with a fourth groove 105 corresponding to the third groove 104, and the fourth groove 105 is used to avoid the structure of the inner cooling layer 150a at the third groove 104.

[0073] Specifically, as Figure 4 shown, the first side wall 151 is divided into three layers corresponding to the inner cooling layer 150a, the intermediate thermal shielding layer 150b, and the outer vacuum layer 150c respectively. Similarly, the second side wall 152 and the head 153 are each divided into three layers. The first groove, the third groove 104, and the fourth groove 105 correspond to each other in the axial direction.

[0074] When processing the outer vacuum layer 150c, the structure corresponding to the first groove of the outer vacuum layer 150c and the structures corresponding to both sides of the first groove in the axial direction of the outer vacuum layer 150c can be formed by stamping or welding, etc., and then the various parts of the structure are connected by welding to form the overall structure of the outer vacuum layer 150c, which is convenient for processing and can make the structure corresponding to the first groove of the outer vacuum layer 150c continuous and sealable. Similarly, the inner cooling layer 150a and the intermediate thermal shielding layer 150b can be processed in the same way as the outer vacuum layer 150c, which will not be elaborated here.

[0075] Please refer to Figure 6 , in one embodiment, the gradient coil 110 includes: a first gradient coil portion 111 and a second gradient coil portion 112 arranged in sequence along the axial direction. The first gradient coil portion 111 and the second gradient coil portion 112 are located on different sides of the first groove along the axial direction. The gradient coil 110 further includes a first intermediate connection portion 113, and the first intermediate connection portion 113 is located between the first gradient coil portion 111 and the second gradient coil portion 112 and is respectively connected to the first gradient coil portion 111 and the second gradient coil portion 112. The first intermediate connection portion 113 is made of a non-metallic material with a decay rate lower than that of the first gradient coil portion 111 and the second gradient coil portion 112.

[0076] The radio frequency coil 120 includes a first radio frequency coil portion 121 and a second radio frequency coil portion 122 arranged axially in sequence. The first radio frequency coil portion 121 and the second radio frequency coil portion 122 are located on different sides of the first groove axially. The radio frequency coil 120 further includes a second intermediate connection portion 123. The second intermediate connection portion 123 is located between the first radio frequency coil portion 121 and the second radio frequency coil portion 122 and is connected to the first radio frequency coil portion 121 and the second radio frequency coil portion 122 respectively. The second intermediate connection portion 123 is made of a non-metallic material such as a material with an attenuation rate lower than that of the first radio frequency coil portion 121 and the second radio frequency coil portion 122.

[0077] Specifically, as Figure 6 shown, the first gradient coil portion 111, the first intermediate connection portion 113, and the second gradient coil portion 112 are arranged axially in sequence. The position of the first intermediate connection portion 113 corresponds to the first groove. Then, when radiotherapy is performed, the rays emitted by the treatment head 132 pass through the first intermediate connection portion 113 and irradiate the patient. Since the material used for the first intermediate connection portion 113 is a material with a lower attenuation rate, the rays emitted by the treatment head 132 can be attenuated less, and thus the treatment efficiency is higher. Similarly, since the material used for the second intermediate connection portion 123 is a material with a lower attenuation rate, the rays emitted by the treatment head 132 can be attenuated less, and thus the treatment efficiency is higher.

[0078] Preferably, the materials used for the first intermediate connection portion 113 and the second intermediate connection portion 123 can be resin. Specifically, when manufacturing the gradient coil 110, the first gradient coil portion 111 and the second gradient coil portion 112 can be wound on the skeleton of the gradient coil 110, and a position corresponding to the first intermediate connection portion 113 is reserved. Then, resin is poured at the position corresponding to the first intermediate connection portion 113 through a mold, and the first intermediate connection portion 113 can be formed. Similarly, the radio frequency coil 120 can be manufactured in the same way.

[0079] Furthermore, the thickness of the first intermediate connection portion 113 in the radial direction can be reduced so that the thickness of the first intermediate connection portion 113 in the radial direction is less than the thickness of the first gradient coil portion 111 in the radial direction and the thickness of the second gradient coil portion 112 in the radial direction, which can further reduce the attenuation of the rays. Similarly, the thickness of the second intermediate connection portion 123 in the radial direction can be made less than the thickness of the first radio frequency coil portion 121 in the radial direction and the thickness of the second radio frequency coil portion 122 in the radial direction, which can further reduce the attenuation of the rays.

[0080] In other embodiments, the first intermediate connection portion 113 may not be provided, that is, the first gradient coil portion 111 and the second gradient coil portion 112 are axially separated structures, and they are respectively located on different sides of the first groove in the axial direction. Then, the rays emitted by the treatment head 132 will not be attenuated by the gradient coil 110. Further, the second intermediate connection portion 123 may not be provided, so that there are no obstacles in the ray path and the attenuation is basically not present, and the rays can be directly emitted to the patient, greatly improving the treatment effect.

[0081] Preferably, the first gradient coil portion 111 and the second gradient coil portion 112 are axially symmetrically distributed. The first radio frequency coil portion 121 and the second radio frequency coil portion 122 are axially symmetrically distributed.

[0082] In one embodiment, the first intermediate connection portion 113 is provided with a first through hole (not shown) in the radial direction, and the first through hole is used for the rays emitted by the treatment head 132 to pass through. The second intermediate connection portion 123 is provided with a second through hole (not shown) in the radial direction, and the second through hole is used for the rays emitted by the treatment head 132 to pass through.

[0083] Specifically, the first intermediate connection portion 113 may also adopt a hollow structure, that is, a first through hole is provided in the radial direction. The position of the first through hole corresponds to the ray path, so that the rays can pass through the first through hole and be emitted to the patient without being attenuated by the resin material of the first intermediate connection portion 113, and the attenuation of the rays can be further reduced.

[0084] Similarly, the position of the second through hole corresponds to the ray path, so that the rays can pass through the first through hole and the second through hole in sequence and be emitted to the patient, and there are no obstacles in the ray path, further reducing the attenuation of the rays.

[0085] Please refer to Figure 6 , in one embodiment, the radiotherapy component 130 includes a shielding component 133. The shielding component 133 at least covers the treatment head 132.

[0086] In this embodiment, the shielding component 133 includes a first shielding layer covering the treatment head 132 and a second shielding layer covering the rack 131. Specifically, both the first shielding layer and the second shielding layer can adopt ferromagnetic materials or a combination of ferromagnetic materials and electrical shielding materials. Through the shielding of the first shielding layer and the second shielding layer, the interference of the main magnetic field generated by the coil assembly on the treatment head 132 and the rack 131 can be minimized, and at the same time, the influence of the alternating field generated by the treatment head 132 rotating and cutting the main magnetic field on the main magnetic field can be shielded.

[0087] The treatment head 132, the rack 131 and their components can also be modified, and non-ferromagnetic materials are preferably used for manufacturing to reduce the influence of the main magnetic field.

[0088] Please refer toFigure 7 In yet another embodiment, the first groove has a first inclined sidewall 101a and a second inclined sidewall 101b opposite to the first inclined sidewall 101a. The first inclined sidewall 101a inclines away from the second inclined sidewall 101b, and the second inclined sidewall 101b inclines away from the first inclined sidewall 101a.

[0089] Specifically, in this embodiment, the first groove is an annular groove. It can be understood that the bottom wall (not shown), the first inclined sidewall 101a, and the second inclined sidewall 101b of the first groove all extend annularly. As shown in the figure, in this embodiment, the first inclined sidewall 101a inclines away from the second inclined sidewall 101b, and the second inclined sidewall 101b inclines away from the first inclined sidewall 101a, so that the cross-section of the first groove forms a trapezoidal or approximately trapezoidal profile. Correspondingly, by modifying the shapes of the cryogenic vessel 150 and the main coil skeleton 141, the cross-sections of the second groove 103, the third groove 104, and the fourth groove 105 can be formed into trapezoidal cross-sections respectively to adapt to the trapezoidal cross-section shape of the first groove, specifically as Figure 7 shown. Through such a shape design, the stress states of the main coil skeleton 141 and the cryogenic vessel 150 can be improved, not only the stress distribution can be improved, but also the manufacturing process can be optimized.

[0090] Please refer to Figure 3 and Figure 4 . In yet another embodiment of the present application, a superconducting magnet applicable to a magnetic resonance device is further provided. The superconducting magnet includes a cryogenic vessel 150, a main coil structure and a shielding coil structure disposed inside the cryogenic vessel 150. The cryogenic vessel 150 is provided with an axial through hole 133. At different positions along the axis of the through hole 133, the through hole 133 has a first inner diameter and a second inner diameter, and the second inner diameter is greater than the first inner diameter. The shielding coil structure is located outside the main coil structure. The main coil structure includes a main coil skeleton 141 and a main coil 142 wound around the main coil skeleton 141. The main coil skeleton 141 includes two first main coil skeleton parts and a second main coil skeleton part coaxially disposed along the axis of the cryogenic vessel 150. The inner diameter of the second main coil skeleton part is greater than the inner diameter of the first main coil skeleton part. Along the axis of the cryogenic vessel 150, the position of the second main coil skeleton part corresponds to the position where the through hole 133 has the second inner diameter, and the position of the first main coil skeleton part corresponds to the position where the through hole has the first inner diameter.

[0091] Specifically, the cryogenic container 150 has a first sidewall 151. The first sidewall 151 encloses a through-hole 133. Since the second inner diameter is greater than the first inner diameter, the position of the through-hole 133 having the second inner diameter forms the first groove in any of the above embodiments. Since the position of the second main coil skeleton part corresponds to the position of the through-hole 133 having the second inner diameter along the axial direction of the cryogenic container 151, the axial position of the second main coil skeleton part corresponds to the position of the first groove. The two first main coil skeleton parts are respectively located on both sides of the second main coil skeleton part in the axial direction.

[0092] A second main coil part 1422 may be wound around the second main coil skeleton part, or no coil may be wound. One of the two first main coil skeleton parts may wind a first main coil part 1421, and the other may wind a third main coil part 1423.

[0093] Optionally, the cryogenic container 150 includes a first end and a second end that are axially opposite. One of the two first main coil skeleton parts is disposed at a position adjacent to the first end, and the other is disposed at a position adjacent to the second end. The second main coil skeleton part is disposed between the two first main coil skeleton parts.

[0094] Specifically, as Figure 4 shown, in this embodiment, the first end and the second end of the cryogenic container 150 are respectively two end caps 153 that are axially opposite.

[0095] Optionally, a radiotherapy component 130 may be disposed at the position of the through-hole 133 having the second inner diameter.

[0096] The position of the through-hole 133 having the second inner diameter is the position of the first groove. The first groove is formed by the central region / middle region of the first sidewall 151 being recessed radially toward the second main coil skeleton part. The radiotherapy component 130 may be disposed in the first groove.

[0097] In one embodiment, the treatment head 132 of the radiotherapy component 130 may rotate circumferentially in the first groove.

[0098] The first groove may surround the cryogenic container 150 in a circumferential circle, or only surround an arc for a certain distance. Optionally, the cross-sectional shape of the first groove may be square, triangular, trapezoidal, etc., that is, the shape of the first groove is not specifically limited in this embodiment.

[0099] The second embodiment of the present application also provides a magnetic resonance-guided radiotherapy system. The basic structure of the magnetic resonance-guided radiotherapy system in the second embodiment is the same as that of the magnetic resonance-guided radiotherapy system 100 in the first embodiment, which will not be described in detail here. The following focuses on the differences between the magnetic resonance-guided radiotherapy system in the second embodiment and the magnetic resonance-guided radiotherapy system 100.

[0100] Please refer to Figure 8 In the second embodiment, the main coil frame 241 is axially separated into two parts, and the two parts are axially located at different sides of the first groove. The shielding coil frame 242 surrounds the main coil frame 241 and is fixedly connected to the main coil frame 241. The shielding coil frame 242 is axially continuous.

[0101] Specifically, Figure 8 As shown, the main coil skeleton 241 is separated into a first skeleton part 2411 and a second skeleton part 2412 along the axial direction. The first skeleton part 2411 and the second skeleton part 2412 are respectively located on different sides of the first groove along the axial direction. The spacing space between the first skeleton part 2411 and the second skeleton part 2412 forms an annular through groove 203. In this embodiment, the second groove in the first embodiment is replaced by the annular through groove 203, so that the structure of the low-temperature container at the first groove can be avoided.

[0102] The shielding coil skeleton 242 forms a continuous integral structure along the axial direction. The two parts of the main coil skeleton 241 are connected to the shielding coil skeleton 242 through a connecting bracket. The connecting bracket may include a plurality of sub-brackets 243 arranged at intervals along the axial direction, and the two parts of the main coil skeleton 241 are reliably connected to the shielding coil skeleton 242 through the plurality of sub-brackets 243. A wire groove for placing the shielding coil may be provided at each end of the shielding coil skeleton 242.

[0103] In a traditional solenoid superconducting magnet, the main coil is usually larger than the shielding coil in both quantity and size. Generally, several pairs of spaced main coils are arranged along the axial direction, and a pair of spaced shielding coils are arranged around the main coil. The diameter of the shielding coil is significantly larger than the main coil. When the magnet is working normally, a large current, usually hundreds of amperes, flows in the coil, which will generate an axial electromagnetic force of up to tens or even hundreds of tons on the coil. In order to maintain the position and structural stability of the coil, a coil skeleton with extremely strong load-bearing capacity needs to be designed to support the main coil and the shielding coil. Accordingly, the coil skeleton includes a main coil skeleton and a shielding coil skeleton. In the prior art, the shielding coil skeleton is installed on the main coil skeleton. The main coil skeleton is generally an integral structure that is continuous along the axial direction, while the shielding coil skeleton is generally divided into two spaced parts along the axial direction, and a shielding coil is wound around each of the two parts.

[0104] As described above, the difference between the second embodiment of the present application and the coil bobbin in the prior art is that the main coil bobbin 241 is axially separated into a first bobbin part 2411 and a second bobbin part 2412 to form a separated structure, the shielding coil bobbin 242 forms a continuous integral structure axially, and the first bobbin part 2411 and the second bobbin part 2412 are then connected to the continuous shielding coil bobbin 242 through a connecting bracket. This structure can maintain the overall strength and stability of the coil bobbin.

[0105] 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 described in this specification.

[0106] The above-described embodiments only 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 deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A magnetic resonance-guided radiotherapy system, characterized in that, Comprising: A magnetic resonance component, comprising: a superconducting magnet, gradient coils and radio frequency coils. The superconducting magnet is provided with a through hole along the axial direction. The gradient coils and the radio frequency coils are sequentially arranged from outside to inside in the through hole. The inner wall surrounding the through hole is provided with a first groove extending circumferentially; and A radiotherapy component arranged in the first groove; the radiotherapy component includes a gantry and a treatment head. The gantry extends along the same circumferential direction as the first groove. The treatment head is mounted on the gantry and can rotate circumferentially along the gantry; The superconducting magnet includes a superconducting coil assembly and a cryostat. The cryostat is used to accommodate the superconducting coil assembly. The shell of the cryostat has a first side wall, and the first side wall surrounds and forms the through hole; the superconducting coil assembly surrounds the first side wall; The superconducting coil assembly includes a main coil skeleton and a main coil wound around the main coil skeleton. The main coil skeleton surrounds the first side wall; The main coil skeleton continuously extends axially from one end of the superconducting magnet to the other end of the superconducting magnet; The main coil skeleton is provided with a second groove corresponding to the first groove. The second groove is used to avoid the structure of the first side wall at the first groove; The main coil includes a first main coil part, a second main coil part and a third main coil part arranged axially in sequence. The position of the second main coil part corresponds to the position of the second groove axially.

2. The magnetic resonance-guided radiotherapy system according to claim 1, wherein, The position of the second main coil part is axially offset from the position where the treatment head emits rays.

3. The magnetic resonance-guided radiotherapy system according to claim 1, wherein, The radiotherapy component includes a shielding component, and the shielding component at least covers the treatment head.

4. A magnetic resonance device, characterized in that, Comprising: A cryostat provided with a through hole along the axial direction. At different positions along the axial direction of the through hole, the through hole has a first inner diameter and a second inner diameter, and the second inner diameter is greater than the first inner diameter; A main coil structure arranged inside the cryostat; The main coil structure includes a main coil skeleton and a main coil wound around the main coil skeleton; The main coil includes a first main coil part, a second main coil part and a third main coil part arranged axially in sequence; The main coil skeleton includes a first main coil skeleton part and a second main coil skeleton part coaxially arranged along the axis of the cryostat. The inner diameter of the second main coil skeleton part is greater than the inner diameter of the first main coil skeleton part; Along the axial direction of the cryostat, the position of the second main coil skeleton part corresponds to the position where the through hole has the second inner diameter, and the position of the first main coil skeleton part corresponds to the position where the through hole has the first inner diameter; The cryostat includes a first end and a second end arranged axially opposite to each other; One of the two first main coil skeleton parts is arranged at a position adjacent to the first end, and the other is arranged at a position adjacent to the second end; the second main coil skeleton part is arranged between the two first main coil skeleton parts; The second main coil part is wound on the second main coil skeleton part; one of the two first main coil skeleton parts winds the first main coil part, and the other winds the third main coil part.

5. The magnetic resonance device according to claim 4, characterized in that, Further comprising: A radiotherapy component, which is accommodated in the through hole, and the radiotherapy component is located at a position where the through hole has the second inner diameter.

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