A radiation therapy system

Abstract

The present application relates to a radiotherapy system, comprising: a magnetic resonance imaging device, configured to acquire magnetic resonance imaging data related to a region of interest of an object, the magnetic resonance imaging device comprising a magnet; and a radiotherapy device, configured to apply a radiation beam to at least a portion of the region of interest, the radiotherapy device comprising: a linear accelerator, configured to accelerate electrons to generate the radiation beam, the linear accelerator being located in a chamber formed by the inner surface of the magnet, and the length direction of the linear accelerator being parallel to the axis of the magnet; the magnetic resonance imaging device further comprising one or more gradient coils arranged in the chamber, the one or more gradient coils being split gradient coils; the linear accelerator being located in a gap between two adjacent split gradient coils.

Description

Description of the case

[0001] This application is a divisional application filed for a Chinese application with a filing date of June 17, 2020, application number 202080101205.2, and invention name “System and method for magnetic resonance imaging”. Technical Field

[0002] The present application relates to a radiotherapy system, and more particularly, to an image-guided radiotherapy system combining radiotherapy and magnetic resonance imaging technology. Background Art

[0003] Currently, radiation therapy for an object (such as a tumor) is affected by the difficulty in tracking changes (such as movement) in the object during different treatment stages. Today, various imaging technologies can be used to provide real-time images of the object before or during each treatment. For example, a magnetic resonance imaging (MRI) device can be used in conjunction with a radiotherapy device to provide a magnetic resonance image of the object. The magnetic resonance imaging device and the radiotherapy device are combined to form a magnetic resonance imaging image-guided treatment device. It may be difficult to arrange the components of the magnetic resonance imaging device (for example, at least two main magnetic coils, at least two shielding magnetic coils, one or more gradient coils, etc.) and the components of the radiotherapy device (for example, a linear accelerator) in a relatively compact space without causing interference. Therefore, it is desirable to provide a treatment device that provides high treatment quality and has a compact structure. Summary of the invention

[0004] According to one aspect of the present application, a radiotherapy system is provided. The radiotherapy system may include a magnetic resonance imaging (MRI) device configured to acquire magnetic resonance imaging data related to a region of interest (ROI) of an object, the magnetic resonance imaging device including a magnet; and a radiotherapy device configured to apply a radiation beam to at least a portion of the region of interest. The radiotherapy device includes a linear accelerator configured to accelerate electrons to generate the radiation beam, the linear accelerator is located in a chamber formed by the inner surface of the magnet, and the length direction of the linear accelerator is parallel to the axis of the magnet.

[0005] In some embodiments, the magnetic resonance imaging apparatus further comprises: one or more gradient coils disposed in the chamber, the one or more gradient coils surrounding the axis of the magnet.

[0006] In some embodiments, the one or more gradient coils are split gradient coils.

[0007] In some embodiments, the linear accelerator is disposed within an opening formed by an inner surface of the one or more gradient coils.

[0008] In some embodiments, the linear accelerator is disposed at or near an end of the chamber.

[0009] In some embodiments, the radiotherapy apparatus further comprises an annular radiation shielding assembly surrounding the linear accelerator.

[0010] In some embodiments, the linear accelerator is located in a gap between two adjacent split gradient coils.

[0011] In some embodiments, the linear accelerator is disposed at or near a midpoint of the chamber in a length direction of the chamber.

[0012] In some embodiments, the radiotherapy apparatus further comprises a radiation shielding assembly surrounding a portion of the linear accelerator, wherein the surrounding portion of the linear accelerator is closer to the axis of the magnet.

[0013] In some embodiments, the radiotherapy apparatus further comprises at least one deflection magnet configured to deflect the electrons toward a target, and the radiation beam is generated when the electrons collide with the target.

[0014] In some embodiments, a distance between the target and the axis of the magnet is greater than a distance between the linear accelerator and the axis of the magnet.

[0015] In some embodiments, the linear accelerator is located away from a path of the radiation beam from the target to at least a portion of the region of interest.

[0016] In some embodiments, the linear accelerator is located at a first position corresponding to a first circumferential angle of the chamber, and the target is located at a second position corresponding to a second circumferential angle of the chamber, and the first circumferential angle is not equal to the second circumferential angle.

[0017] In some embodiments, the at least one deflection magnet comprises a permanent magnet.

[0018] In some embodiments, the radiotherapy apparatus includes a microwave assembly configured to accelerate electrons, the microwave assembly being operably coupled to the linear accelerator via a waveguide.

[0019] In some embodiments, the magnet includes at least two main magnetic coils; at least two shielding coils, which surround the axis of the magnet and are arranged along the circumference or a portion thereof, and the radius of the at least two shielding magnetic coils from the axis of the magnet is larger than that of the at least two main magnetic coils; and an annular cryostat, in which the at least two main magnetic coils and the at least two shielding coils are arranged.

[0020] Some additional features of the present application may be described in the following description. Some additional features of the present application will be apparent to those skilled in the art through study of the following description and the corresponding drawings or understanding of the production or operation of the embodiments. The features of the present application may be realized and achieved through practice or use of the methods, means and combinations of various aspects of the specific embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present application will be further described by exemplary embodiments. These exemplary embodiments will be described in detail by the accompanying drawings. These embodiments are non-limiting exemplary embodiments, in which the same numbers in each figure represent similar structures, wherein:

[0022] Figure 1 is a block diagram of an exemplary radiation therapy system according to some embodiments of the present application;

[0023] Figure 2A is a schematic diagram of components of an exemplary magnetic resonance imaging device according to some embodiments of the present application;

[0024] Figure 2B is a schematic diagram of components of an exemplary radiotherapy device according to some embodiments of the present application;

[0025] Figure 3 is a schematic diagram of hardware and / or software components of an exemplary computing device according to some embodiments of the present application;

[0026] Figure 4 is a schematic diagram of exemplary hardware and / or software components according to some embodiments of the present application;

[0027] Figure 5 is a flowchart of an exemplary process of applying therapeutic radiation in a radiation therapy system according to some embodiments of the present application;

[0028] Figures 6A to 6F are various views of an exemplary treatment device and trajectories of radiation beams generated by the exemplary treatment device according to some embodiments of the present application; and

[0029] Figures 7A to 7D are various views of exemplary therapeutic devices shown according to some embodiments of the present application. DETAILED DESCRIPTION

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. However, it should be understood by those skilled in the art that the present application can be implemented without these details. In other cases, in order to avoid unnecessarily obscuring the various aspects of the present application, well-known methods, processes, systems, components and / or circuits have been described at a higher level. For those of ordinary skill in the art, it is obvious that various changes can be made to the disclosed embodiments, and without departing from the principles and scope of the present application, the general principles defined in the present application can be applied to other embodiments and application scenarios. Therefore, the present application is not limited to the embodiments shown, but conforms to the broadest scope consistent with the scope of the application.

[0031] The terms used in this application are only for the purpose of describing specific example embodiments and are not restrictive. The singular forms "one", "an" and "the" used in this application may also include plural forms unless the context clearly indicates an exception. It should also be understood that the terms "including" and "comprising" used in this application specification only indicate the presence of the features, integers, steps, operations, components and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, components, parts and / or combinations thereof.

[0032] It is to be understood that the terms "system", "engine", "unit", "module" and / or "block" used in this application are methods for distinguishing different components, elements, parts, portions or assemblies of different levels in ascending order. However, these terms may also be replaced by other expressions if the same purpose can be achieved.

[0033] Generally, the words "module", "unit" or "block" used herein refer to logic embodied in hardware or firmware, or a collection of software instructions. The modules, units or blocks described herein may be implemented as software and / or hardware, and may be stored in any type of non-temporary computer-readable medium or other storage device. In some embodiments, software modules / units / blocks may be compiled and linked to an executable program. It should be understood that software modules may be called from other modules / units / blocks or from themselves, and / or may be called in response to detected events or interruptions. Software modules / units / blocks configured for execution on a computing device may be provided on a computer-readable medium, such as a compact disc, a digital video disc, a flash drive, a disk, or any other tangible medium, or as a digital download (and may be initially stored in a compressed or installable format, requiring installation, decompression or decryption prior to execution). The software code here may be partially or completely stored in a storage device of a computing device performing the operation, and applied in the operation of the computing device. Software instructions may be embedded in firmware, such as an erasable programmable read-only memory. It should also be understood that hardware modules / units / blocks may be included in connected logical components, such as gates and triggers, and / or may include programmable units, such as programmable gate arrays or processors. The modules / units / blocks or computing device functions described herein may be implemented as software modules / units / blocks, but may be represented by hardware or firmware. Typically, the modules / units / blocks described herein refer to logical modules / units / blocks, which may be combined with other modules / units / blocks or divided into sub-modules / sub-units / sub-blocks, although they are physical organizations or storage devices. This description may apply to a system, an engine, or a portion thereof.

[0034] It is understood that, unless the context clearly indicates otherwise, when a unit, engine, module, or block is referred to as being "on," "connected," or "coupled" to another unit, engine, module, or block, it may be directly on, connected, coupled, or in communication with the other unit, engine, module, or block, or there may be intermediate units, engines, modules, or blocks. In this application, the term "and / or" may include any one or more of the relevant listed items or combinations thereof.

[0035] It should be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, the various elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the exemplary embodiments of the present application.

[0036] These and other features, characteristics and functions and methods of operation of the related structural elements of the present application, as well as the combination of components and manufacturing economy, may become more apparent from the following description of the accompanying drawings, which constitute a part of the specification of this application. However, it should be understood that the drawings are for illustration and description purposes only and are not intended to limit the scope of the present application. It should be understood that the drawings are not drawn to scale.

[0037] The present application provides devices for medical applications, such as devices for disease treatment and / or diagnostic purposes. The devices disclosed in the present application are mainly described with respect to magnetic resonance imaging radiotherapy (MRI-RT) systems. It should be understood that this is for illustrative purposes only. In some embodiments, the imaging system may include a positron emission tomography radiotherapy (PET-RT) system, an emission computed tomography radiotherapy (ECT-RT) system, a computed tomography radiotherapy (CT-RT) system, and the like.

[0038] One aspect of the present application relates to a radiotherapy system. The radiotherapy system may include a magnetic resonance imaging device and a radiotherapy device. The magnetic resonance imaging device may include a magnet. The radiotherapy device may include a linear accelerator configured to accelerate electrons to generate a radiation beam. In a conventional magnetic resonance imaging-radiotherapy system, the linear accelerator may be located in a chamber formed by the inner surface of the magnet, rather than outside the chamber. In this case, the source-axis distance (SAD) from the radiation source of the radiotherapy device to the rotation axis of the gantry may be less than the source-axis distance of a conventional magnetic resonance imaging-radiotherapy system. In addition, the length direction of the linear accelerator may be parallel to the axis of the magnet. The length direction of the linear accelerator may be parallel to the main magnetic field direction generated by the magnet. Therefore, the influence of the main magnetic field on the acceleration of electrons in the linear accelerator can be eliminated or reduced, and the magnetic shielding of the linear accelerator can be omitted.

[0039] Figure 1 1 is a block diagram of an exemplary radiotherapy system according to some embodiments of the present application. In some embodiments, the radiotherapy system 100 may be a multimodal imaging system, including, for example, a magnetic resonance imaging-radiotherapy (MRI-RT) system, a positron emission tomography-radiotherapy (PET-RT) system, etc. In order to better understand the present application, the magnetic resonance imaging-radiotherapy system may be described as an example of the radiotherapy system 100, and is not intended to limit the scope of the present application.

[0040] like Figure 1As shown, the radiation therapy system 100 may include a treatment device 110, one or more processing devices 120, a network 130, a storage device 140, and one or more terminal devices 150. In some embodiments, the treatment device 110, the one or more processing devices 120, the storage device 140, and / or the terminal device 150 may be connected and / or communicate with each other via a wireless connection (e.g., a wireless connection provided by the network 130), a wired connection (e.g., a wired connection provided by the network 130), or any combination thereof.

[0041] The treatment device 110 may include a magnetic resonance imaging device. The magnetic resonance imaging device may generate image data associated with a magnetic resonance signal generated by scanning an object or a portion thereof. In some embodiments, the object may include a body, a substance, an object, etc., or any combination thereof. In some embodiments, the object may include a specific part of the body, a specific organ, or a specific tissue, etc. For example, the object may include the patient's head, brain, neck, body, shoulder, arm, chest, heart, stomach, blood vessel, soft tissue, knee, foot, etc. According to the type of magnet of the magnetic resonance imaging device, the magnetic resonance imaging device may include a permanent magnet magnetic resonance imaging scanner, a superconducting magnet magnetic resonance imaging scanner, or a resistive electromagnet magnetic resonance imaging scanner, etc. In some embodiments, according to the magnetic field strength generated by the magnetic resonance imaging device, the magnetic resonance imaging device may include a high field magnetic resonance imaging scanner, a mid-field magnetic resonance imaging scanner, and a low field magnetic resonance imaging scanner, etc. In some embodiments, the magnetic resonance imaging device may be a closed-cell (cylindrical) type, an open-cell type, etc. In some embodiments, the treatment device 110 may send the image data to one or more processing devices 120, a storage device 140, and / or a terminal device 150 via a network 130 for further processing. For example, the image data may be sent to one or more processing devices 120 to generate magnetic resonance images, or may be stored in a storage device 140 .

[0042] For illustration purposes, Figure 1 A coordinate system 160 including an X-axis, a Y-axis, and a Z-axis (referred to as an X direction, a Y direction, and a Z direction, respectively) is provided. Figure 1 The X-axis and Z-axis shown may be horizontal, and the Y-axis may be vertical. As shown in the figure, from the direction facing the front side of the treatment device 110, the positive X-direction along the X-axis may be the direction from the right side to the left side of the treatment device 110; Figure 1 As shown, the positive Y direction of the Y axis can be the direction from the lower part to the upper part of the treatment device 110; Figure 1 As shown, the positive Z direction along the Z axis may refer to a direction from the back side to the front side of the treatment device 110 , in which direction the object is moved out of the imaging or treatment channel (or referred to as an imaging or treatment chamber) of the treatment device 110 .

[0043] In some embodiments, the magnetic resonance imaging device of the treatment device 110 can be guided to select an anatomical slice of the object along a slice selection direction, and scan the anatomical slice to obtain at least two echo signals from the slice. During scanning, spatial encoding within the slice can be achieved by spatial encoding coils (e.g., X coils and Y coils) along phase encoding directions and frequency encoding directions. The echo signals can be sampled, and the corresponding sampled data can be stored in a K-space matrix for generating image data of the object or a portion thereof. For illustrative purposes, the slice selection direction herein may correspond to the Z direction defined by the coordinate system 160 and the Kz direction in the K-space; the phase encoding direction may correspond to the Y direction defined by the coordinate system 160 and the Ky direction in the K-space; and the frequency encoding direction may correspond to the X direction defined by the coordinate system 160 and the Kx direction in the K-space. It should be noted that the slice selection direction, the phase encoding direction, and the frequency encoding direction may be modified according to actual needs, and the modification may not depart from the scope of the present application. More description of the magnetic resonance imaging device can be found elsewhere in the present application. For example, see Figure 2A and its description.

[0044] The treatment device 110 may also include a radiotherapy device. The radiotherapy device may apply a radiation beam to a target area of ​​the object. The radiation beam may include a particle beam, a photon beam, etc. Exemplary particle rays may include neutrons, protons, electrons, muons, heavy ions, alpha rays, etc., or any combination thereof. Exemplary photon rays may include X-rays, gamma rays, ultraviolet rays, lasers, etc., or any combination thereof. For the purpose of illustration, a radiotherapy device that provides an X-ray beam may be described as an example.

[0045] In some embodiments, the radiotherapy device can be operably connected to the magnetic resonance imaging device. In some embodiments, one or more components of the radiotherapy device can be disposed in the magnetic resonance imaging device. For example, a linear accelerator of the radiotherapy device can be disposed in a scanning channel for placing an object (also referred to as a chamber) of the magnetic resonance imaging device. As another example, at least one deflection magnet of the radiotherapy device can also be disposed in the chamber of the magnetic resonance imaging device.

[0046] In some embodiments, a magnetic resonance imaging device can acquire image data of an object before, during, and / or after at least a portion of radiotherapy is performed on the object. The radiotherapy device can apply a radiation beam to a target area of ​​the object based at least in part on the image data provided by the magnetic resonance imaging device. Because the radiotherapy of the target area may be affected by the difficulty of tracking changes (e.g., movement) in the target area during different treatment phases. The image data provided by the magnetic resonance imaging device can provide a basic real-time image of the target area before or within a treatment course. For example, the image data can be reconstructed to generate an image of the object in order to locate the target area of ​​the object and / or determine the dose of the X-ray beam. As another example, magnetic resonance imaging image data that has not been reconstructed into a magnetic resonance imaging image can be used to identify the movement of the object, which can be used to guide the radiation beam to be delivered to the target area of ​​the object.

[0047] The subject may be placed on the treatment table. The treatment table may support the subject for imaging using a magnetic resonance imaging device and / or for radiation therapy using a radiation therapy device. The treatment table may be rotatable along the longitudinal direction (i.e., Figure 1 The treatment table can be moved forward and backward in the Z direction (in the Z direction). The longitudinal direction of the treatment table can be parallel to the axial direction of the chamber of the magnetic resonance imaging device. If the object needs to be treated, the treatment table carrying the object can be moved to the treatment position. If the object needs to be imaged, the treatment table carrying the object can be moved to the imaging position.

[0048] One or more processing devices 120 can process data and / or information obtained from the treatment device 110, the storage device 140 and / or the terminal device 150. For example, one or more processing devices 120 can process image data and reconstruct at least one magnetic resonance image based on the image data. As another example, one or more processing devices 120 can determine the location of the treatment area and the radiation dose to be added to the treatment area based on at least one magnetic resonance image. Magnetic resonance images can have advantages, such as superior soft tissue contrast, high resolution and geometric accuracy, which can allow accurate positioning of the treatment area. Magnetic resonance images can be used to detect changes in the treatment area during radiation therapy (e.g., changes in the chest due to the subject's breathing), so that the treatment plan of the radiation therapy can be adjusted accordingly.

[0049] In treatment planning, the radiation dose may be determined based on, for example, the synthetic electron density information. In some embodiments, the synthetic electron density information may be generated based on magnetic resonance images.

[0050] In some embodiments, the one or more processing devices 120 may be a single processing engine that communicates with the magnetic resonance imaging device and the radiotherapy device of the treatment device 110 and processes data from them. In some embodiments, the one or more processing devices 120 may include at least two processing devices. One of the at least two processing devices may communicate with the magnetic resonance imaging device of the treatment device 110 and process data from the device, and another of the at least two processing devices may communicate with the radiotherapy device of the treatment device 110 and process data from the device. The at least two processing devices may communicate with each other.

[0051] In some embodiments, one or more processing devices 120 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, one or more processing devices 120 may be local or remote relative to the therapeutic device 110. For example, one or more processing devices 120 may access information and / or data from the therapeutic device 110, storage device 140, and / or terminal device 150 via network 130. As another example, one or more processing devices 120 may be directly connected to the therapeutic device 110, terminal device 150, and / or storage device 140 to access information and / or data. In some embodiments, one or more processing devices 120 may be implemented on a cloud platform. The cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, a cloud-to-cloud cloud, a multi-cloud, etc., or any combination thereof.

[0052] The network 130 may include any suitable network that can facilitate information and / or data exchange for the radiation therapy system 100. In some embodiments, one or more components of the radiation therapy system 100 (e.g., the treatment device 110, one or more processing devices 120, the storage device 140, or the terminal device 150) may communicate information and / or data with one or more other components of the radiation therapy system 100 via the network 130. For example, the one or more processing devices 120 may obtain image data from the treatment device 110 via the network 130. As another example, the one or more processing devices 120 may obtain user instructions from the terminal device 150 via the network 130. The network 130 may include a public network (e.g., the Internet), a private network (e.g., a local area network (LAN), a wide area network (WAN)), a wired network (e.g., Ethernet), a wireless network (e.g., an 802.11 network, a Wi-Fi network), a cellular network (e.g., a Long Term Evolution (LTE) network), a frame relay network, a virtual private network (“VPN”), a satellite network, a telephone network, a router, a hub, a switch, a server computer, etc., or any combination thereof. In some embodiments, the network 130 may include one or more network access points. For example, the network 130 may include wired and / or wireless network access points, such as base stations and / or Internet exchange points, through which one or more components of the radiation therapy system 100 may connect to the network 130 to exchange data and / or information.

[0053] The storage device 140 may store data, instructions, and / or any other information. In some embodiments, the storage device 140 may store data obtained from one or more processing devices 120 and / or terminal devices 150. In some embodiments, the storage device 140 may store data and / or instructions that one or more processing devices 120 may execute or use to execute the exemplary methods described in this specification. In some embodiments, the storage device 140 may include a mass storage device, a removable storage device, a cloud-based storage device, a volatile read-write memory, a read-only memory (ROM), etc., or any combination thereof. Exemplary mass storage may include a disk, an optical disk, a solid-state drive, etc. Exemplary removable storage may include a flash drive, a floppy disk, an optical disk, a memory card, a compressed disk, a tape, etc. Exemplary volatile read-write memory may include a random access memory (RAM). Exemplary random access memory may include a dynamic random access memory (DRAM), a double data rate synchronous dynamic random access memory (DDR-SDRAM), a static random access memory (SRAM), a thyristor random access memory (T-RAM), a zero capacitance random access memory (Z-RAM), etc. Exemplary read-only memories may include mask read-only memories (MROMs), programmable read-only memories (PROMs), erasable programmable read-only memories (EPROMs), electrically erasable programmable read-only memories (EEPROMs), compact disk read-only memories (CD-ROMs), digital versatile disk read-only memories, etc. In some embodiments, storage device 140 may be implemented on a cloud platform, as described elsewhere in this specification.

[0054] In some embodiments, the storage device 140 may be connected to the network 130 to communicate with one or more other components of the radiation therapy system 100 (e.g., one or more processing devices 120 or terminal device 150). One or more components of the radiation therapy system 100 may access data or instructions stored in the storage device 140 via the network 130. In some embodiments, the storage device 140 may be part of one or more processing devices 120.

[0055] The terminal device 150 can be connected to and / or communicate with the treatment device 110, one or more processing devices 120 and / or storage device 140. For example, one or more processing devices 120 can obtain a treatment plan from the terminal device 150. As another example, the terminal device 150 can obtain image data from the treatment device 110 and / or storage device 140. In some embodiments, the terminal device 150 may include a mobile device 151, a tablet computer 152, a laptop computer 153, etc., or any combination thereof. For example, the mobile device 151 may include a mobile phone, a personal digital assistant (PDA), a laptop computer, a tablet computer, a desktop computer, etc., or any combination thereof. In some embodiments, the terminal device 150 may include an input device, an output device, etc. The input device may include alphanumeric keys and other keys input by a keyboard, a touch screen (e.g., with tactile or haptic feedback), voice input, eye tracking input, a brain monitoring system, or any other similar input mechanism. The input information received by the input device can be transmitted to one or more processing devices 120 via, for example, a bus for further processing. Other types of input devices may include cursor control devices, such as a mouse, trackball, or cursor direction keys, etc. Output devices may include displays, speakers, printers, etc., or any combination thereof. In some embodiments, terminal device 150 may be part of one or more processing devices 120.

[0056] This description is intended to be illustrative, not limiting, of the scope of the present application. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other features of the exemplary embodiments described herein may be combined in various ways to obtain additional and / or alternative exemplary embodiments. For example, the storage device 140 may be a data storage device including a cloud computing platform, such as a public cloud, a private cloud, a community, a hybrid cloud, and the like. In some embodiments, one or more processing devices 120 may be integrated into the treatment device 110. As another example, the radiotherapy system 100 may also include a control device configured to determine one or more parameters of the treatment device 110 in order to optimize the imaging and / or radiotherapy of the object. In some embodiments, the control device may be a part of the processing device 120 and / or the terminal 150. However, these changes and modifications do not depart from the scope of the present application.

[0057] Figure 2A is a schematic diagram of components of an exemplary magnetic resonance imaging device according to some embodiments of the present application. Figure 2AOne or more components of a magnetic resonance imaging device 200 are shown in the figure. As shown, the main magnet 201 can generate a first magnetic field (or referred to as a main magnetic field), which can be applied to an object (also referred to as an object) exposed to the magnetic field. The main magnet 201 can include a resistive magnet or a superconducting magnet, both of which require a power supply (not shown) to operate. Alternatively, the main magnet 201 can include a permanent magnet. The main magnet 201 may include a chamber in which the object is placed. The main magnet 201 can also control the uniformity of the generated main magnetic field. One or more shim coils can be located in the main magnet 201. The shim coils placed in the gap of the main magnet 201 can compensate for the inhomogeneity of the magnetic field of the main magnet 201. The shim coils can be energized by a shim power supply.

[0058] The gradient coil 202 may be located within the main magnet 201. The gradient coil 202 may generate a second magnetic field (or referred to as a gradient field, including gradient fields Gx, Gy, and Gz). The second magnetic field may be superimposed on the main magnetic field generated by the main magnet 201 and distort the main magnetic field so that the magnetic orientation of the protons of the object may vary with their position in the gradient field, thereby encoding spatial information into an echo signal generated by a region of the imaged object. The gradient coil 202 may include an X coil (e.g., configured to generate a gradient field Gx corresponding to an X direction), a Y coil (e.g., configured to generate a gradient field Gy corresponding to a Y direction), and / or a Z coil (e.g., configured to generate a gradient field Gz corresponding to a Z direction) ( Figure 2A ). In some embodiments, the Z coil can be based on a circular (Maxwell) coil design, while the X coil and the Y coil can be based on a saddle (Golay) coil configuration design. The three sets of coils can generate three different magnetic fields for position encoding. The gradient coil 202 can allow the echo signal to be spatially encoded for image construction. The gradient coil 202 can be connected to one or more of the X gradient amplifier 204, the Y gradient amplifier 205, or the Z gradient amplifier 206. One or more of the three amplifiers can be connected to the waveform generator 216. The waveform generator 216 can generate a gradient waveform applied to the X gradient amplifier 204, the Y gradient amplifier 205, and / or the Z gradient amplifier 206. The amplifier can amplify the waveform. The amplified waveform can be applied to one of the coils in the gradient coil 202 to generate a magnetic field on the X axis, the Y axis, or the Z axis, respectively. The gradient coil 202 can be designed for a closed-bore magnetic resonance scanner or an open-bore magnetic resonance scanner. In some cases, all three sets of coils of the gradient coil 202 can be energized, thereby generating three gradient fields. In some embodiments of the present application, the X coil and the Y coil can be energized to generate a gradient field in the X direction and the Y direction. As used herein, Figure 2A The X-axis, Y-axis, Z-axis, X-direction, Y-direction and Z-direction in the description are the same as Figure 1 Same or similar to that described in .

[0059] In some embodiments, a radio frequency (RF) coil 203 may be located within the main magnet 201 and used as a transmitter, a receiver, or both. The RF coil 203 may be connected to RF electronics 209, which may be configured or used as one or more integrated circuits (ICs) used as waveform transmitters and / or waveform receivers. The RF electronics 209 may be connected to a radio frequency power amplifier (RFPA) 207 and an analog-to-digital converter (ADC) 208.

[0060] When used as a transmitter, the RF coil 203 can generate an RF signal that provides a third magnetic field for generating echo signals associated with the imaged object region. The third magnetic field can be perpendicular to the main magnetic field. The waveform generator 216 can generate RF pulses. The RF pulses can be amplified by the RF power amplifier 207, processed by the RF electronics 209, and applied to the RF coil 203 to generate an RF signal in response to the strong current generated by the RF electronics 209 based on the amplified RF pulses.

[0061] When used as a receiver, the radio frequency coil may be responsible for detecting the echo signal. After excitation, the echo signal generated by the object may be sensed by the radio frequency coil 203. The receiving amplifier may then receive the sensed echo signal from the radio frequency coil 203, amplify the sensed echo signal, and provide the amplified echo signal to the analog-to-digital converter 208. The analog-to-digital converter 208 may convert the echo signal from an analog signal to a digital signal. The digital echo signal may then be sent to the processing device 120 for sampling.

[0062] In some embodiments, the gradient coil 202 and the RF coil 203 may be positioned circumferentially relative to the object. One skilled in the art will appreciate that the main magnet 201 , the gradient coil 202 , and the RF coil 203 may be positioned in various configurations around the object.

[0063] In some embodiments, the RF power amplifier 207 can amplify the RF pulse (e.g., the power of the RF pulse, the voltage of the RF pulse), thereby generating an amplified RF pulse to drive the RF coil 203. The RF power amplifier 207 may include a transistor-based RF power amplifier, a vacuum tube-based RF power amplifier, etc., or any combination thereof. A transistor-based RF power amplifier may include one or more transistors. A vacuum tube-based RF power amplifier may include a triode, a tetrode, a klystron, etc., or any combination thereof. In some embodiments, the RF power amplifier 207 may include a linear RF power amplifier or a nonlinear RF power amplifier. In some embodiments, the RF power amplifier 207 may include one or more RF power amplifiers.

[0064] In some embodiments, the magnetic resonance imaging device 200 may further include an object positioning system (not shown). The object positioning system may include an object support and a transport device. The object may be placed on the object support and positioned in the chamber of the main magnet 201 by the transport device.

[0065] A magnetic resonance imaging device (e.g., the magnetic resonance imaging device 200 disclosed in the present application) is generally used to obtain an internal image of a specific region of interest (ROI) from a patient, which region of interest can be used for diagnosis, treatment, etc., or a combination thereof. The magnetic resonance imaging device may include a main magnet (e.g., main magnet 201) assembly for providing a strong and uniform main magnetic field to align the individual magnetic moments of hydrogen atoms in the patient's body. In this process, the hydrogen atoms oscillate around their magnetic poles at their unique Larmor frequency. If the tissue is subjected to an additional magnetic field that is tuned to the Larmor frequency, the hydrogen atoms absorb additional energy, thereby rotating the net alignment moment of the hydrogen atoms. The additional magnetic field can be provided by a radio frequency excitation signal (e.g., a radio frequency signal generated by the radio frequency coil 203). When the additional magnetic field is removed, the magnetic moment of the hydrogen atoms rotates back to a position aligned with the main magnetic field, thereby emitting an echo signal. The echo signal is received and processed to form a radio frequency image. T1 relaxation can be a process in which the net magnetization grows / recovers to an initial maximum value parallel to the main magnetic field. T1 can be the time constant for the re-growth of longitudinal magnetization (e.g., along the main magnetic field). T2 relaxation can be the process by which the transverse component of magnetization decays or dephases. T2 can be the time constant for the decay / dephasing of the transverse magnetization.

[0066] If the main magnetic field is uniformly distributed throughout the patient's body, the RF excitation signal can non-selectively excite all hydrogen atoms in the sample. Therefore, in order to image a specific part of the patient's body, the magnetic field gradients Gx, Gy and Gz (e.g., generated by the gradient coil 202) in the x, y and z directions, with specific timing, frequency and phase, can be superimposed on the uniform magnetic field so that the RF excitation signal excites the hydrogen atoms in the desired slice of the patient's body, and unique phase and frequency information is encoded in the echo signal according to the position of the hydrogen atoms in the "image slice".

[0067] Typically, the portion of the patient's body to be imaged is scanned by a series of measurement cycles, wherein the radio frequency excitation signal and the magnetic field gradients Gx, Gy and Gz vary according to the magnetic resonance imaging protocol being used. The protocol can be designed for one or more tissues to be imaged, diseases and / or clinical scenarios. The protocol can include a specific number of pulse sequences in different planes and / or with different parameters. The pulse sequence may include a spin echo sequence, a gradient echo sequence, a diffusion sequence, an inversion recovery sequence, or the like, or any combination thereof. For example, the spin echo sequence may include a fast spin echo (FSE) pulse sequence, a turbo spin echo (TSE) pulse sequence, a rapid capture with relaxation enhancement (RARE) pulse sequence, a half Fourier capture single excitation turbo spin echo (HASTE) pulse sequence, a turbo gradient spin echo (TGSE) pulse sequence, or the like, or any combination thereof. As another example, the gradient echo sequence may include a balanced steady-state free precession (bSSFP) pulse sequence, a spoiled gradient echo (GRE) pulse sequence, an echo planar imaging (EPI) pulse sequence, a steady-state free precession (SSFP), or the like, or any combination thereof. The protocol may also include information regarding image contrast and / or ratio, region of interest, slice thickness, imaging type (e.g., T1-weighted imaging, T2-weighted imaging, proton density weighted imaging, etc.), T1, T2, echo type (spin echo, fast spin echo (FSE), fast recovery FSE, single shot FSE, gradient echo, fast imaging with steady-state processing, etc.), flip angle value, acquisition time (TA), echo time (TE), repetition time (TR), echo train length (ETL), number of phases, number of excitations (NEX), inversion time, bandwidth (e.g., RF receiver bandwidth, RF transmitter bandwidth, etc.), etc., or any combination thereof. For each MRI scan, the resulting echo signals may be digitized and processed to reconstruct an image according to the MRI imaging protocol used.

[0068] Figure 2B is a schematic diagram of components of an exemplary radiotherapy device according to some embodiments of the present application. Figure 2B As shown, the radiotherapy device 250 may include a radiation beam generator 252, a beam control device 254, a target 256 and a treatment head 258. The radiation beam generator 252 may be configured to generate a radiation particle beam. For example, the radiation particle beam may include neutrons, electrons, hadrons (e.g., protons, ions) or other types of radiation particles. The description in the following figure provides a radiation particle beam of an electron. It will be appreciated that this is for illustrative purposes only and is not intended to limit the scope of the present application.

[0069] In some embodiments, the radiation beam generator 252 may include a linear accelerator (also referred to as a "linear accelerator"). The linear accelerator may be configured to accelerate electrons in a linear accelerator accelerating tube to form an electron beam having a specific energy level. For example, electrons may be accelerated to form a high-energy level electron beam in the accelerating tube. A high-energy level electron beam refers to an electron beam having an energy greater than a threshold energy. For example, the threshold energy may be 5Mev, 10Mev, 20Mev, 30mev, 40mev, 50mev, 100mev, 200mev, etc. Accordingly, an electron beam having an energy lower than the threshold energy may be referred to as a low-energy level electron beam.

[0070] The beam control device 254 can be configured to control the radiation particle beam generated by the radiation beam generator 252. For example, the radiation particle beam generated by the radiation beam generator 252 can be deflected, defocused and / or focused by the beam control device 254. In some embodiments, the beam control device 254 can control the radiation particle beam to achieve a desired position, direction, spatial distribution, energy distribution, beam shape, etc. As used in this application, the position can refer to the point or area on the target (e.g., tungsten plate, molybdenum plate, etc.) with which the electrons in the radiation particle beam collide. The direction can refer to the direction in which the electrons in the radiation particle beam are emitted. The spatial distribution can refer to the distribution of electrons in the radiation particle beam in three-dimensional space. The energy distribution can refer to the distribution of electron energy in the radiation particle beam. The beam shape can refer to the cross-sectional shape of the radiation particle beam.

[0071] In some embodiments, the beam control device 254 may include a deflection device and a beam profile modulator. The deflection device may be configured to deflect the radiation particle beam. By way of example only, the radiation beam generator 252 may emit an electron beam in a direction that may pass through a deflection device before reaching an object. When the electron beam passes through the deflection device, the deflection device may change the trajectory (e.g., position and direction) of the electron beam. Exemplary deflection devices may include a microwave cavity, a magnet (e.g., a permanent magnet, an electromagnet, etc.), a magnetic lens, etc., or any combination thereof. The beam profile modulator may be configured to control the beam shape of the radiation particle beam. By way of example only, the beam profile modulator may include one or more beam limiting devices, such as a blocker, which may block a specific portion of the radiation particle beam.

[0072] When the accelerated electron beam collides with the target 256, the target 256 can generate a radiation beam for radiation therapy of an object (e.g., a target area of ​​the object). For example, the electron beam emitted from the radiation beam generator 252 can be deflected onto the target 256 to generate high-energy level X-rays according to the bremsstrahlung effect. In some embodiments, the target 256 can be made of a material including aluminum, copper, silver, tungsten, etc., or an alloy thereof, or any combination thereof.

[0073] Treatment head 258 can be positioned at a specific location and use a radiation beam to treat a subject from a specific angle. In some embodiments, one or more components of beam control device 254 can be mounted on or integrated into treatment head 258. For example, a beam profile modulator (e.g., a collimator) can be integrated into treatment head 258. During radiation therapy, a gantry supporting one or more components of the radiation therapy device can rotate along an axis, and treatment head 258 and beam control device 254 can rotate with the gantry. For example, the gantry can be rotated according to the following example: Figure 1 Coordinate system 160 is shown as being rotated about the Z axis in the XY plane defined by the coordinate system 160 .

[0074] In some embodiments, the radiation therapy device may include at least two treatment heads, each of which may be equipped with a beam control device 254. The beam control device 254 (e.g., a multi-leaf collimator (MLC)) may be mounted on or integrated into the corresponding treatment head. In some embodiments, the radiation beam generator 252 and the beam control device 254 may be an integrated component.

[0075] Figure 3 is a schematic diagram of hardware and / or software components of an exemplary computing device 300 according to some embodiments of the present application. The computing device 300 can be used to implement any component of the radiation therapy system 100 described herein. For example, the processing device 120 and / or the terminal 150 can be implemented on the computing device 300 through its hardware, software program, firmware, or a combination thereof. Although only one such computing device is shown, for convenience, the computer functions related to the radiation therapy system 100 described herein can be implemented in a distributed manner on multiple similar platforms to distribute the processing load. Figure 3 As shown, computing device 300 may include processor 310 , memory 320 , input / output (I / O) 330 , and communication port 340 .

[0076] The processor 310 can execute computer instructions (e.g., program code) and perform the functions of the processing device 120 according to the technical means described herein. The computer instructions may include, for example, routines, programs, objects, components, data structures, processes, modules, and functions, which perform specific functions described herein. For example, the processor 310 can process data obtained from the magnetic resonance imaging device 200, the terminal 150, the storage device 140, and / or any other component of the radiotherapy system 100. In some embodiments, the processor 310 may include one or more hardware processors, such as a microcontroller, a microprocessor, a reduced instruction set computer (RISC), an application specific integrated circuit (ASIC), an application specific instruction set processor (ASIP), a central processing unit (CPU), a graphics processing unit (GPU), a physical processing unit (PPU), a microcontroller unit, a digital signal processor (DSP), a field programmable gate array (FPGA), an advanced RISC machine (ARM), a programmable logic device (PLD), any circuit or processor capable of performing one or more functions, etc., or any combination thereof.

[0077] For illustration only, only one processor is described in the computing device 300. However, it should be noted that the computing device 300 in the present application may also include multiple processors, and therefore, the operations and / or method operations performed by one processor as described in the present application may also be performed by multiple processors jointly or individually. For example, if in the present application, the processor of the computing device 300 performs operation A and operation B at the same time, it should be understood that operation A and operation B may also be performed jointly or individually by two or more different processors in the computing device 300 (for example, the first processor performs operation A, the second processor performs operation B, or the first and second processors perform operations A and B together).

[0078] The memory 320 may store data / information obtained from the magnetic resonance imaging device 200, the storage device 140, the terminal 150, and / or any other component of the radiotherapy system 100. In some embodiments, the memory 320 may include a mass storage device, a removable storage device, a volatile read-write memory, a read-only memory (ROM), etc., or any combination thereof. In some embodiments, the memory 320 may store one or more programs and / or instructions to perform the exemplary methods described in the present application. For example, the memory 320 may store a program executed by the processing device 120 to generate an image of a region of interest (ROI) of an object.

[0079] Input / output 330 may input and / or output signals, data, information, and the like. In some embodiments, input / output 330 may be used by a user to interact with processing device 120. In some embodiments, input / output 330 may include input devices and output devices. Input devices may include alphanumeric keys and other keys input via a keyboard, a touch screen (e.g., with tactile or haptic feedback), voice input, eye tracking input, a brain monitoring system, or any other similar input mechanism. Input information received by an input device may be transmitted to another component (e.g., processing device 120) via, for example, a bus for further processing. Other types of input devices may include cursor control devices, such as a mouse, a trackball, or cursor direction keys, and the like. Output devices may include displays (e.g., liquid crystal displays (LCDs), displays based on light emitting diodes (LEDs), flat panel displays, curved screens, television devices, cathode ray tubes (CRTs), touch screens), speakers, printers, and the like, or combinations thereof.

[0080] The communication port 340 can be connected to a network (e.g., network 130) to facilitate data communication. The communication port 340 can establish a connection between the processing device 120 and the magnetic resonance imaging device 200, the terminal 150 and / or the storage device 140. The connection can be a wired connection, a wireless connection, any other communication connection that can realize data transmission and / or reception, and / or any combination of these connections. The wired connection can include, for example, a cable, an optical cable, a telephone line, etc., or any combination thereof. The wireless connection can include, for example, a Bluetooth connection, a Wi-Fi connection, a WiMax connection, a WLAN connection, a ZigBee connection, a mobile network connection (e.g., 3G, 4G, 5G), etc., or a combination thereof. In some embodiments, the communication port 340 can be and / or include a standardized communication port, such as RS232, RS485, etc. In some embodiments, the communication port 340 can be a specially designed communication port. For example, the communication port 340 can be designed according to the digital imaging and medical communication (DICOM) protocol.

[0081] Figure 4 4 is a schematic diagram of exemplary hardware and / or software components according to some embodiments of the present application. In some embodiments, one or more components of the radiotherapy system 100 (eg, the terminal 150 and / or the processing device 120 ) may be implemented on the mobile device 400 .

[0082] like Figure 4As shown, the mobile device 400 may include a communication platform 410, a display 420, a graphics processing unit (GPU) 430, a central processing unit (CPU) 440, an input / output 450, a memory 460, and a storage 490. In some embodiments, any other suitable components, including but not limited to a system bus or a controller (not shown), may also be included in the mobile device 400. In some embodiments, a mobile operating system 470 (e.g., iOS, Android, Windows Phone) and one or more applications 480 may be loaded from the storage 490 to the memory 460 for execution by the CPU 440. The application 480 may include a browser or any other suitable mobile application for receiving and presenting information related to the radiation therapy system 100. User interaction with the information stream may be implemented through the input / output 450 and provided to the processing device 120 and / or other components of the radiation therapy system 100 through the network 150.

[0083] In order to implement the various modules, units and their functions described in this application, a computer hardware platform can be used as a hardware platform for one or more components described herein. A computer with user interface elements can be used to implement a personal computer (PC) or any other type of workstation or terminal device. If the computer is properly programmed, the computer can also be used as a server.

[0084] Figure 5 is a flow chart of an exemplary process for applying therapeutic radiation in a radiation therapy system according to some embodiments of the present application. In some embodiments, Figure 5 One or more operations of the process 500 may be performed at Figure 1 The radiation therapy system 100 shown is implemented in FIG. Figure 5 The process 500 shown may be stored in the form of instructions in the storage device 140 and executed by Figure 1 The one or more processing devices 120 shown call and / or execute. For the purpose of illustration, the present application takes the implementation of the process 500 in one or more processing devices 120 as an example for description. It should be noted that the process 500 can also be similarly implemented in the terminal device 150.

[0085] In 502, one or more processing devices 120 may acquire magnetic resonance (MR) data about a region of interest (ROI) through a magnetic resonance imaging device. The magnetic resonance data may be magnetic resonance signals received from a subject by a radio frequency coil of a magnetic resonance imaging device (eg, the magnetic resonance imaging device 200).

[0086] In some embodiments, the region of interest may refer to an area in the subject, such as a lesion area. For example, the region of interest may be an area associated with a tumor of the subject. In some embodiments, the region of interest may be a specific part of the body, a specific organ, or a specific tissue, such as the head, brain, neck, body, shoulder, arm, chest, heart, stomach, blood vessel, soft tissue, knee, foot, etc. of the subject.

[0087] In 504, one or more processing devices 120 may reconstruct a magnetic resonance image of the region of interest based on the magnetic resonance data. Based on the magnetic resonance data, the magnetic resonance image may reflect the distribution of atomic nuclei in the subject. Various types of image reconstruction techniques may be used to reconstruct the magnetic resonance image. Exemplary image reconstruction techniques may include Fourier reconstruction, constrained image reconstruction, regularized image reconstruction in parallel magnetic resonance imaging, etc., or variations thereof, or any combination thereof.

[0088] In some embodiments, the magnetic resonance image can be used to determine the radiation beam to be applied to the target area (e.g., at least a portion of the region of interest). For example, one or more processing devices 120 can determine the location of at least a portion of the region of interest and / or the radiation dose to be added based on the magnetic resonance image.

[0089] In some embodiments, it may take a long time (eg, several minutes) to reconstruct a magnetic resonance image of the region of interest. If the size of the region of interest is large, it may be difficult to reconstruct a magnetic resonance image of the region of interest in real time during radiation therapy.

[0090] In some embodiments, in order to generate a magnetic resonance image of a region of interest within a relatively short period of time (e.g., a few seconds), one or more processing devices 120 may reconstruct a magnetic resonance image of at least a portion of the region of interest. The magnetic resonance image of the entire region of interest (also referred to as a main magnetic resonance image) may be reconstructed in advance (e.g., one day, two hours, half an hour, etc. before radiotherapy). The processing device 120 may obtain magnetic resonance data of at least a portion of the region of interest acquired by a magnetic resonance imaging device, and reconstruct a magnetic resonance image of at least a portion of the region of interest during radiotherapy (e.g., before a radiation beam is applied to at least a portion of the region of interest). The processing device 120 may combine a magnetic resonance image of at least a portion of the region of interest with the main magnetic resonance image. For example, one or more processing devices 120 may replace a corresponding portion in the main magnetic resonance image with a magnetic resonance image of at least a portion of the region of interest. In this way, during radiotherapy, the main magnetic resonance image may be updated in a relatively short time.

[0091] In 506, one or more processing devices 120 may determine a parameter associated with at least a portion of the region of interest based on the magnetic resonance image. In some embodiments, the parameter associated with at least a portion of the region of interest may include a size of a cross-section of a lesion (e.g., a tumor) corresponding to at least a portion of the region of interest. In some embodiments, the parameter associated with at least a portion of the region of interest may indicate a shape of the cross-section of the lesion.

[0092] In 508, one or more processing devices 120 may generate a control signal based on parameters associated with at least a portion of the region of interest. The control signal may be dynamically adjusted based on a plurality of magnetic resonance images acquired at different time points during the radiotherapy. In some embodiments, the control signal may include parameters associated with the radiation beam applied to the tumor. For example, the control signal may include a dose of an X-ray beam, a duration of the radiation beam applied to at least a portion of the region of interest, and the like. As another example, the control signal may include parameters of a multi-leaf collimator that shapes the radiation beam projected onto at least a portion of the region of interest. In some embodiments, the control signal may include parameters associated with the movement of one or more components of a radiotherapy device (e.g., a radiotherapy device 250). For example, the control signal may include parameters associated with one or more positions of a radiation source of a radiotherapy device (e.g., a target 256 of a radiotherapy device 250). As another example, the control signal may include parameters associated with the height and / or position of a treatment table of a radiotherapy device for properly positioning a patient so that a target region (e.g., a region corresponding to a lesion) in the patient may properly receive a radiation beam from the radiotherapy device.

[0093] In 510, one or more processing devices 120 may send a control signal to the radiotherapy device to cause the radiotherapy device to deliver a radiation beam to at least a portion of the region of interest. During therapeutic radiation, the transmission source of the radiotherapy device may rotate about the rotation axis. The dose of the X-ray beam, the duration of the radiation beam applied to at least a portion of the region of interest, the shape of the multi-leaf collimator, and / or the position of the treatment table may be adjusted according to the control signal.

[0094] In some embodiments, as described above, a target region (e.g., at least a portion of a region of interest) can be determined based on image data acquired from a magnetic resonance imaging device during radiation therapy. A radiation beam can then be generated by the radiation therapy device and delivered to the target region. The dose of the radiation beam and / or the location of the target region can be determined in near real time with the help of the magnetic resonance imaging device.

[0095] It should be noted that the above description is provided for illustrative purposes only and is not intended to limit the scope of the present application. For those skilled in the art, various changes and modifications may be made based on the description of the present application. For example, the main magnetic resonance image may be obtained from a storage device (e.g., storage device 140) in the radiotherapy system 100. As another example, the parameters associated with at least a portion of the region of interest determined based on the magnetic resonance image may also include at least a portion of the region of interest in a coordinate system (e.g., such as Figure 1 However, these changes and modifications do not depart from the scope of the present application.

[0096] Figures 6A to 6F 6 is a diagram of various views of an exemplary treatment device and a trajectory of a radiation beam generated by the exemplary treatment device according to some embodiments of the present application. Treatment device 600 may include a magnetic resonance imaging device and a radiotherapy device. The magnetic resonance imaging device may be configured to generate magnetic resonance data of a region of interest of an object. The radiotherapy device may be configured to apply a radiation beam to at least a portion of the region of interest based on a magnetic resonance image reconstructed from the magnetic resonance data.

[0097] Fig. 6A and 6B It is half of the cross-section of the treatment device shown in some embodiments of the present application. Figure 6C is a three-dimensional (3D) structure of a therapeutic device according to some embodiments of the present application. In some embodiments, Figure 6C The 3D structure shown in FIG. 1 can be visualized by using a cut plane (e.g., Figure 6C The cross section is formed by cutting the treatment device 600 along the YZ plane (as shown in FIG. 1 ) or a plane parallel to the YZ plane and viewing the treatment device 600 along the negative direction of the X axis. In some embodiments, the cross section is formed by cutting the treatment device 600 along the YZ plane (as shown in FIG. 1 ) and viewing the treatment device 600 along the negative direction of the X axis. Fig. 6A and 6B As shown, it can be seen in the cross section (such as Fig. 6A and 6B is formed in the YZ plane shown. Fig. 6A is a front view of a half cross section of the therapeutic device 600 . Figure 6B is an oblique view of a half cross section of the treatment device 600 .

[0098] Fig.6D 600 according to some embodiments of the present application. In some embodiments, the side view of the therapeutic device 600 can be formed by viewing the therapeutic device 600 along the negative direction of the Z axis by the reference coordinate system 630. Fig. 6E is an enlarged view of a portion of a treatment device, including a trajectory of an electron beam generated by a treatment device 600 according to some embodiments of the present application. Fig. 6Fis a schematic diagram of the trajectory of the electron beam generated by the treatment device 600 according to some embodiments of the present application. Figures 6A to 6F The therapeutic device 600 is described in detail.

[0099] In some embodiments, the magnetic resonance imaging device may be or include a permanent magnet magnetic resonance imaging scanner, a superconducting magnet magnetic resonance imaging scanner, or a resistive electromagnet magnetic resonance imaging scanner, etc., depending on the type of magnet of the magnetic resonance imaging device. In some embodiments, the magnetic resonance imaging device may be or include a high-field magnetic resonance imaging scanner, a medium-field magnetic resonance imaging scanner, and a low-field magnetic resonance imaging scanner, etc., depending on the magnetic field strength generated by the magnet of the magnetic resonance imaging device. In some embodiments, the magnetic resonance imaging device may be a closed-hole (cylindrical) type, or an open-hole type, etc. The magnetic resonance imaging device may include a magnet 601.

[0100] like Figures 6A to 6C As shown, the magnet 601 may have an annular shape around an axis 610, which is represented by a lightly dotted line. The axis 610 may be parallel to the Z direction of the coordinate system 630. Fig. 6A and 6B As shown, the inner surface of magnet 601 can form chamber 620, which is represented by a rectangular frame, and the rectangular frame is composed of thick double dotted lines. Magnet 601 can generate a magnetic field. Magnet 601 can be of various types, including, for example, permanent magnets, superconducting electromagnets, resistive electromagnets, etc. The following description is provided, and magnet 601 can be a superconducting electromagnet. It should be understood that it is only for illustrative purposes and is not intended to limit the scope of the present application.

[0101] like Figures 6A to 6C As shown, the magnet 601 may include at least two main magnetic coils 602 , at least two shielding coils 604 , and a cryostat 606 .

[0102] In some embodiments, at least two main magnetic coils 602 and at least two shielding coils 604 may be housed in a cryostat 606. The cryostat 606 may contain a coolant. The coolant may include, for example, liquid helium. The at least two main magnetic coils 602 and at least two shielding coils 604 may be at least partially immersed in the coolant in the cryostat 606. The coolant may maintain the at least two main magnetic coils 602 and at least two shielding coils 604 at a low temperature (e.g., 4.2K) such that the at least two main magnetic coils 602 and at least two shielding coils 604 may maintain a superconducting state.

[0103] The cryostat 606 may have the shape of an annular space with an axis 610. In some embodiments, the contour of the cryostat 606 may at least partially coincide with the contour of the magnet 601. At least two main magnetic coils 602 may be disposed around the axis 610 in the cryostat 606. When the at least two main magnetic coils 602 carry current (e.g., the current flows in the positive direction of the Z axis), the at least two main magnetic coils 602 may generate a uniform main magnetic field (e.g., a static magnetic field B) in a specific area (e.g., the hole 620). 0 ). The direction of the main magnetic field can be parallel to the axis 610 in the chamber 620.

[0104] The at least two shielding coils 604 can shield the magnetic field generated by the at least two main magnetic coils 602 in the area outside the magnetic resonance imaging device. In some embodiments, the at least two shielding coils 604 can carry current in a direction opposite to the current direction on the at least two main magnetic coils 602 (for example, the negative direction of the Z axis). The magnetic field generated by the at least two shielding coils 604 can reduce or eliminate the magnetic field generated by the at least two main magnetic coils 602 in the area outside the magnetic resonance imaging device. In some embodiments, the at least two shielding coils 604 can be an annular coil disposed along the axis 610, coaxial with the at least two main magnetic coils 602. In some embodiments, the at least two shielding magnetic coils 604 have a larger radius from the axis 610 than the at least two main magnetic coils 602.

[0105] The magnetic resonance imaging apparatus may further include one or more gradient coils 608. The one or more gradient coils 608 may generate magnetic fields to be superimposed on the main magnetic field B in the X, Y and / or Z directions. 0 In some embodiments, the one or more gradient coils 608 may include at least one X-coil, at least one Y-coil, and / or at least one Z-coil, etc. The X-coil may be energized to generate a gradient field in the X direction. The Y-coil may be energized to generate a gradient field in the Y direction. The Z-coil may be energized to generate a gradient field in the Z direction. By way of example only, at least one Z-coil may be based on a circular (Maxwell) coil design, and at least one X-coil and at least one Y-coil may be based on a saddle (Golais) coil design.

[0106] In some embodiments, the gradient magnetic field may include a slice selection gradient field corresponding to the Z direction, a phase encoding (PE) gradient field corresponding to the Y direction, a readout (RO) gradient field corresponding to the X direction, etc. The gradient magnetic fields in different directions can be used to encode the spatial information of the magnetic resonance signal. In some embodiments, the gradient magnetic field can also be used to perform at least one function of flow encoding, flow compensation, flow dephasing, etc., or any combination thereof.

[0107] One or more gradient coils 608 may be located in the chamber 620. In some embodiments, one or more gradient coils 608 may be disposed on or near the inner surface of the magnet 601. In some embodiments, one or more gradient coils 608 may be configured as at least one gradient coil group. Each gradient coil group may include at least one gradient coil (e.g., an X coil, a Y coil, and / or a Z coil). In some embodiments, the gradient coil group may have an annular structure around the axis 610. At least one gradient coil group may be disposed on or near the inner surface of the magnet 601 along its circumferential direction. At least one gradient coil group or a portion thereof may be continuously or spaced apart from each other in its longitudinal direction (i.e., in the Z direction). When at least one gradient coil group is spaced apart from each other, the distances between at least two pairs of adjacent gradient coil groups may be the same or different. One or more gradient coils 608 may be energized at room temperature rather than at low temperatures (e.g., 4.2K).

[0108] The radiation therapy device may include a linear accelerator 612 , a radiation shielding assembly 614 , a deflection device 615 , a target 616 , and a treatment head 618 .

[0109] The linear accelerator 612 can accelerate electrons to form an electron beam of a specific energy level. In some embodiments, the linear accelerator 612 can accelerate electrons using microwave technology. In some embodiments, the linear accelerator 612 is operably coupled to a microwave device (not shown). The microwave device can be configured to accelerate electrons in the linear accelerator 612. In some embodiments, the linear accelerator 612 can be operably coupled to the microwave device via a rotating waveguide. When the linear accelerator 612 rotates around the axis 610 during the radiation treatment of the object, the rotating waveguide can keep the microwave device stationary relative to the magnetic resonance imaging device. In some embodiments, during the radiation treatment of the object, the microwave device can also rotate around the axis 610 along the linear accelerator 612.

[0110] The linear accelerator 612 may be located in a chamber 620 formed by the inner surface of the magnet 601. In some embodiments, the length direction of the linear accelerator 612 may be parallel to the axis 610. Specifically, the linear accelerator 612 may include an accelerating tube. The accelerating tube may provide a linear path for accelerating electrons. The axis of the accelerating tube may be parallel to the axis 610 (or the Z direction). In these embodiments, the moving direction of the electrons in the linear accelerator 612 may be parallel to the main magnetic field B. 0 The acceleration of electrons in the linear accelerator 612 can be (substantially) protected from the main magnetic field B. 0 Therefore, when the length direction of the linear accelerator 612 is parallel to the axis 610, the linear accelerator 612 may not require magnetic shielding.

[0111] In some embodiments, the linear accelerator 612 can be disposed within one or more gradient coils 608 (ie, within an opening formed by the inner surface of one or more gradient coils 608). Figures 6A to 6C As shown in the half cross-section of the treatment device 600, the linear accelerator 612 can be closer to the axis 610 than the one or more gradient coils 608. In some embodiments, the linear accelerator 612 can be disposed at any suitable position within the opening formed by the inner surface of the one or more gradient coils 608. For example, the linear accelerator 612 can be connected to or close to (e.g., a distance of 1 cm, 2 cm, 5 cm, etc.) the inner surface of the opening. As another example, the linear accelerator 612 can be disposed on the axis 610 (i.e., the centerline of the linear accelerator 612 can coincide with the axis 610).

[0112] In some embodiments, the linear accelerator 612 may be disposed at or near the end of the chamber 620 in the Z direction. The linear accelerator 612 may include a first end at which electrons in the electron beam begin to be accelerated and a second end at which the electron beam is emitted outwardly in the Z direction. The chamber 620 may include a first end at the rear side and a second end at the front side of the treatment device 600. Figure 1 When viewed along the negative direction of the Z axis, the front side and the back side can be two sides of the treatment device. Figure 1 The back side is visible in Figure 1 Not visible in.

[0113] In some embodiments, the first end of the linear accelerator 612 can be aligned with the first end or the second end of the chamber 620. In some embodiments, the first end of the linear accelerator 612 can be close to the first end or the second end of the chamber 620. For illustrative purposes only, the distance between the first end of the linear accelerator 612 and the first end or the second end of the chamber 620 can be 0 cm, 5 cm, 10 cm, 20 cm, 50 cm, etc. In some embodiments, the distance between the first end of the linear accelerator 612 and the first end or the second end of the chamber 620 can be adjusted. For example, the linear accelerator 612 can be fixed on a mobile platform (not shown in the figure). The mobile platform can move in the Z direction. The distance between the first end of the linear accelerator 612 and the first end or the second end of the chamber 620 can be adjusted by controlling the movement of the mobile platform. In some embodiments, the movement of the mobile platform can be achieved by a sliding structure, such as a slide rail.

[0114] The linear accelerator 612 (e.g., an accelerating tube of the linear accelerator 612) may be at least partially surrounded by a radiation shielding assembly 614. The radiation shielding assembly 614 may protect an object and / or one or more components of the magnetic resonance imaging device from the radiation generated by the linear accelerator 612. In some embodiments, the radiation shielding assembly 614 may provide a cavity coaxial with the longitudinal direction of the linear accelerator 612, at least one end of which is open to allow the electron beam emitted by the linear accelerator 612 to pass through. In some embodiments, the radiation shielding assembly 614 may have an annular structure surrounding the linear accelerator 612. The length of the radiation shielding assembly 614 in the Z direction may be equal to or greater than the length of the linear accelerator 612.

[0115] The radiation shielding assembly 614 can be made of a material capable of absorbing radiation generated by the radiation beam of the linear accelerator 612 to provide radiation shielding for the object and / or one or more components of the magnetic resonance imaging device. Exemplary materials that absorb radiation may include materials for absorbing photon rays and / or materials for absorbing particle rays (e.g., neutron rays). Materials for absorbing photon rays may include steel, aluminum, lead, tungsten, etc., or alloys thereof, or combinations thereof. Materials for absorbing neutron rays may include boron, graphite, etc., or alloys thereof, or combinations thereof.

[0116] When the accelerated electron beam collides with the target 616, the target 616 can generate a radiation beam for radiotherapy of an object (e.g., a region of interest of at least a portion of the object). For example, the electron beam emitted from the linear accelerator 612 can be deflected onto the target 616 to generate high-energy X-rays based on the bremsstrahlung effect. In some embodiments, the target 616 can be made of a material including aluminum, copper, silver, tungsten, etc., or an alloy thereof, or any combination thereof. Alternatively, the target 616 can be made of a composite material including tungsten and copper, tungsten and silver, tungsten and aluminum, etc., or an alloy thereof, or any combination thereof. In some embodiments, the target 616 can be a circular plate with a relatively small thickness (e.g., a few microns to tens of microns).

[0117] In some embodiments, one or more of the gradient coils 608 may be split gradient coils. Each split gradient coil may include at least one gradient coil. In some embodiments, the split gradient coils may have an annular structure surrounding the axis 610. In some embodiments, the split gradient coils may be spaced apart from each other along the Z direction. For illustration purposes only, Figures 6A to 6CAs shown, one or more gradient coils 608 can be configured as two split gradient coils around an axis 610. The two split gradient coils can be spaced apart to form an annular gap 624. The depth of the annular gap 624 can be equal to the thickness of the gradient coils. In some embodiments, the target 616 can be located in the annular gap 624 between the two split gradient coils. In some embodiments, the target 616 can be located at the center of the gap 624.

[0118] It should be noted that the location of the target 616 is for illustrative purposes only and is not intended to limit the scope of the present application. In some alternative embodiments, the target 616 may be located at any suitable location in the chamber 620. For example, the target 616 may be located within an opening formed by the inner surface of one or more gradient coils 608. In some embodiments, an annular groove may be provided on the inner surface of the cryostat 606. The target 616 may be disposed in an annular groove of the cryostat 606.

[0119] The deflection device 615 can be configured to deflect the electron beam emitted by the linear accelerator 612 toward the target 616 along the trajectory 622. Exemplary deflection devices may include a microwave cavity, a deflection magnet (e.g., a permanent magnet, an electromagnet, etc.), a magnetic lens, etc., or any combination thereof. In some embodiments, the deflection device 615 may include at least one deflection magnet. The at least one deflection magnet may be a permanent magnet, an electromagnet, etc. In some embodiments, if the energy of the electron beam emitted from the linear accelerator 612 is fixed, the deflection device 615 may be implemented by a permanent magnet.

[0120] Figures 6D to 6F The trajectory of the electron beam is described in detail 622. Figures 6D to 6F , the electron beam emitted from the linear accelerator 612 may be deflected along the curved trajectory 622 to the outer surface of the target 616. The outer surface of the target 616 may refer to a surface of the target 616 that is at a greater distance from the axis 610.

[0121] Since the electrons emitted from the exit of the linear accelerator 612 are located in the main magnetic field B generated by at least two main magnetic coils 602, 0 The deflection device 615 can be properly designed to make the electron beam move in the main magnetic field B generated by at least two main magnetic coils 602. 0 After traveling along the trajectory 622 under the combined effect of the deflection magnetic field generated by the deflection device 615, the electron beam may (substantially) vertically (or referred to as substantially vertically) collide with the target 616. In some embodiments, the radiotherapy device may further include one or more correction coils along the electron beam trajectory 622. The one or more correction coils may be configured to correct the trajectory 622 of the electron beam so that the electron beam collide with the target 616 substantially vertically.

[0122] In some embodiments, the deflection device 615 may include at least one arc-shaped deflection channel. The arc-shaped deflection channel may be (substantially) shielded from the main magnetic field B. 0 The electron beam can be deflected to the target 616 in at least one arc-shaped deflection channel within the deflection magnetic field generated by the deflection device 615 .

[0123] The radiation beam from the target 616 can pass through the treatment head 618. The treatment head 618 can be configured to transmit the radiation beam to the target area of ​​the object from a specific angle. The treatment head 618 may include a collimator (not shown in the figure) for reshaping the radiation beam. For example, the collimator can adjust the radiation shape, radiation area, etc. of the radiation beam by blocking a specific part of the radiation beam. In some embodiments, the collimator may include a primary collimator, a flat filter, and at least one secondary collimator. In some embodiments, the collimator may be a multi-leaf collimator. The multi-leaf collimator may include at least two independent leaves that move in and out of the radiation beam path independently to block a specific part of the radiation beam. When at least two independent leaves move in and out, the shape of the radiation beam can change to form different grooves that approximate a cross-sectional view of the target area (e.g., at least a portion of the region of interest) viewed along the radiation beam. In some embodiments, the multi-leaf collimator may include one or more leaves. For example, the multi-leaf collimator may have only one layer of leaves, and the height of the multi-leaf collimator along the axis of the radiation beam may be between 7 and 10 centimeters. As another example, the multi-leaf collimator may include two layers, and the height of the multi-leaf collimator may be at least 15 cm.The leaves of the multi-leaf collimator may be made of at least one material with a higher atomic number, such as tungsten.

[0124] Treatment head 618 can be placed anywhere on radiation beam path 623. For example, treatment head 618 can be placed close to target 616. As another example, treatment head 618 can be placed relatively far from target 616.

[0125] In some embodiments, one or more of the deflection device 615, the target 616, and the treatment head 618 can be fixed relative to the linear accelerator 612, so as to rotate with the linear accelerator 612 around the axis 610 during the radiation treatment of the object. In some embodiments, the linear accelerator 612, the deflection device 615, the target 616, and the treatment head 618 can be contained in a housing of the radiation treatment device. In some embodiments, the linear accelerator 612, the deflection device 615, the target 616, and the treatment head 618 can be relatively fixed by a physical structure (e.g., a mechanical structure: one or more rods, one or more plates, not shown), glue, etc., or a combination thereof. The cross-section of the housing can be any suitable shape, such as a ring, an arc, etc. In some embodiments, one or more gradient coils 608 can also be contained in the housing. The housing can be connected to the gantry. For example, the housing can be connected to the gantry by a mechanical joint. The gantry can rotate around the axis 610. Then, during radiation treatment of the subject, components of the radiation treatment device in the housing can be rotated along the gantry about axis 610 so that radiation beams can be emitted to a target area of ​​the subject from any of the circumferential positions along the circumference of treatment device 600 or defined by treatment device 600.

[0126] In these embodiments, many components of the radiotherapy apparatus (e.g., linear accelerator 612, deflection device 615, target 616, and treatment head 618) may be disposed in chamber 620. The source-axis distance (SAD) from the target 616 of the radiotherapy apparatus to the rotation axis of the gantry (i.e., axis 610) may be smaller than that of a conventional magnetic resonance imaging-radiotherapy system, thereby increasing the dose rate of the radiation beam and enhancing the therapeutic effect of the target area of ​​the subject.

[0127] Figures 7A to 7D 700 are various views of an exemplary therapeutic device according to some embodiments of the present application. The therapeutic device 700 may include a device similar to Figures 6A-6F The magnetic resonance imaging equipment and radiotherapy equipment. Fig. 7A and 7B It is half of the cross-section of the treatment device 700 shown according to some embodiments of the present application. Fig. 7A is a front view of a half cross section of the therapeutic device 700 . Figure 7B is an oblique view of a half cross section of the treatment device 700 . Figure 7C 700 according to some embodiments of the present application. In some embodiments, the side view of the therapeutic device 700 can be formed by viewing the therapeutic device 700 along the negative direction of the Z axis by the reference coordinate system 730. Fig.7D is an enlarged view of a portion of a treatment device 700, including a diagram of the trajectory of an electron beam generated by the treatment device according to some embodiments of the present application. Fig. 7A and Figure 7B To describe the therapeutic device 700.

[0128] The magnetic resonance imaging device may include a magnet 701 and one or more gradient coils 708. The magnet 701 may include at least two main magnetic coils 702, at least two shielding coils 704, and a cryostat 706. In some embodiments, the at least two main magnetic coils 702, at least two shielding coils 704, the cryostat 706, and one or more gradient coils 708 may be coaxially or concentrically arranged around an axis 710. The radiotherapy device may include a linear accelerator 712, a radiation shielding assembly 714, a deflection device (not shown), a target 716, and a treatment head 718.

[0129] Compared to one or more components of treatment device 600, Fig. 7A and 7B The position of the linear accelerator 712 shown may be different from Fig. 6A and 6B The position of the linear accelerator 612 is shown. In some embodiments, the linear accelerator 712 can be disposed between two adjacent split gradient coils. Each split gradient coil can include at least one gradient coil. In some embodiments, the split gradient coil can have an annular structure surrounding the axis 710. In some embodiments, the linear accelerator 712 can be disposed at or near the midpoint of the chamber 720 formed by the magnet 701 (or the cryostat 706 has an annular shape) along the length direction of the chamber 720. Fig. 7A and 7B As shown, one or more gradient coils 708 can be configured as two split gradient coils. The two split gradient coils can be spaced apart from each other to form a gap 724. In some embodiments, the gap 724 between the two split gradient coils can be greater than the length of the linear accelerator 712. The linear accelerator 712 can be located in the gap 724 between the two split gradient coils. The length direction of the linear accelerator 712 can be parallel to the axis 710. By arranging the linear accelerator 712 in the gap 724 between the two split gradient coils, the thickness of the housing that accommodates the linear accelerator 712, the radiation shielding assembly 714, the deflection device 715, the target 716, and the treatment head 718, which is substantially equal to the distance from the target 716 to the outer surface of the radiation shielding assembly 714 in the Y direction, can be greatly reduced. If the space for placing the object in the chamber 720 remains constant, the circumferential size of the treatment device 700 can be reduced relative to the treatment device 600.

[0130] like Fig. 7A and 7BAs shown, with respect to the cross-section of the treatment device 700 , the target 716 can be placed above the linear accelerator 712 (ie, the distance between the target 716 and the axis 710 can be greater than the distance between the linear accelerator 712 and the axis 710 ).

[0131] The trajectory 722 of the electron beam is as follows Figure 7C and 7D As shown. Figure 7C and 7D As shown, the electron beam emitted from the linear accelerator 712 can be deflected to the outer surface of the target 716 along the curved trajectory 722. The outer surface of the target 716 can refer to the surface of the target 716, which is at a greater distance from the axis 710. The linear accelerator 712 and the target 716 can correspond to different circular angles. As used in this application, the circular angle is an angle in the XY plane relative to the coordinate system 730. In some embodiments, the circular angle can be defined with reference to the axis 710 in the chamber 720 and the negative direction of the X axis. For example, the linear accelerator 712 can correspond to a circular angle of 90 degrees. For illustration only, the linear accelerator 712 can be located at a first position corresponding to a first circular angle of the chamber 720. The target 716 can be located at a second position corresponding to a second circular angle of the chamber 720. The first circular angle is different from the second circular angle.

[0132] The deflection device 715 is designed to enable the electron beam emitted from the linear accelerator 712 to be deflected in the main magnetic field B generated by at least two main magnetic coils 702. 0 After traveling along the trajectory 722 under the combined effect of the deflection magnetic field generated by the deflection device, it can (substantially) collide with the target 716 vertically. In some embodiments, the deflection device 715 may include at least one arc-shaped deflection channel. The arc-shaped deflection channel may be covered or surrounded by a magnetic shielding material, which (substantially) shields the main magnetic field B generated by the at least two main magnetic coils 702. 0 The electron beam can be deflected in at least one arc-shaped deflection channel within the deflection magnetic field generated by the deflection device to the target 716. After the electron beam collides with the target 716, a radiation beam can be generated. The radiation beam from the target 716 can pass through the treatment head 618 and be transmitted to the target area of ​​the subject from a specific angle.

[0133] The linear accelerator 712 can be spaced away from a radiation beam path 723 from the target 716 to the target region of the subject. In some embodiments, a line connecting the target region of the subject and the target 716 can be at an angle to another line connecting the target region of the subject and the center of the linear accelerator 712. The angle can be greater than a threshold value, for example, 5 degrees, 10 degrees, 15 degrees, 20 degrees, 30 degrees, etc.

[0134] Thus, the radiation shielding assembly 714 that shields the linear accelerator 712 (e.g., the accelerating tube of the linear accelerator 612) from radiation can vary. The radiation shielding assembly 714 can protect the subject and / or one or more components of the magnetic resonance imaging device from the radiation generated by the linear accelerator 712. In some embodiments, the radiation shielding assembly 714 can surround a portion of the linear accelerator 712. The surrounding portion of the linear accelerator 712 can be closer to the axis 710. In some embodiments, such as Fig. 7A and 7B As shown, the radiation shielding assembly 614 can have a semi-annular structure, surrounding the lower portion of the linear accelerator 612 of the cross section of the treatment device 700 (i.e., the semi-annular portion of the linear accelerator 712 is closer to the axis 710). The length of the radiation shielding assembly 714 in the Z direction can be equal to or greater than the length of the linear accelerator 712.

[0135] It should be noted that the above description is provided for illustrative purposes only and is not intended to limit the scope of the present application. For those of ordinary skill in the art, various changes and modifications can be made according to the description of the present application. For example, an annular groove can be provided on the inner surface of the cryostat 606. The linear accelerator 712 and the target 716 can be provided in a circular or annular groove of the cryostat 706. However, these changes and modifications do not depart from the scope of the present application.

[0136] The basic concepts have been described above. Obviously, for those of ordinary skill in the art who have read this application, the above invention disclosure is only for example and does not constitute a limitation of this application. Although not explicitly stated here, those of ordinary skill in the art may make various modifications, improvements and amendments to this application. Such modifications, improvements and amendments are suggested in this application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of this application.

[0137] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0138] In addition, it will be appreciated by those skilled in the art that various aspects of the present application may be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product, or combination of substances, or any new and useful improvements thereto. Accordingly, various aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may all be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". In addition, various aspects of the present application may be represented as a computer product located in one or more computer-readable media, the product including computer-readable program code.

[0139] In addition, unless explicitly stated in the claims, the order of the processing elements and sequences described in this application, the use of alphanumeric characters, or the use of other names are not intended to limit the order of the processes and methods of this application. Although the above disclosure discusses some invention embodiments that are currently considered useful through various examples, it should be understood that such details are only for illustrative purposes, and the attached claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this application. For example, although the implementation of the various components described above can be embodied in a hardware device, it can also be implemented as a pure software solution, for example, installation on an existing server or mobile device.

[0140] Similarly, it should be noted that in order to simplify the description disclosed in this application and thus facilitate the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of the present application, multiple features are sometimes grouped into one embodiment, figure, or description thereof. However, this method of the present application should not be interpreted as reflecting the intention that the claimed object material to be scanned requires more features than those expressly stated in each claim. On the contrary, the subject matter of the invention should have fewer features than the single embodiment described above.

[0141] In some embodiments, numbers representing quantities or characteristics used to describe and claim certain embodiments of the present application should be understood to be modified by the terms "approximately", "approximately" or "substantially" in some cases. For example, "approximately", "approximately" or "substantially" may represent a ±20% variation of the value it describes, unless otherwise stated. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the desired characteristics of individual embodiments. In some embodiments, numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, such numerical values ​​are set as accurately as possible within the feasible range.

[0142] All patents, patent applications, patent application publications, and other materials (such as papers, books, specifications, publications, records, things, and / or the like) referred to herein are hereby incorporated by reference in their entirety for all purposes, except any prosecution record related to such documents, any such documents that are inconsistent or conflicting with this document, or any such documents that have the effect of limiting the broad scope of the claims that may or may not be related to this document. For example, if there is any inconsistency or conflict between the description, definition, and / or use of terms associated with any incorporated material and the terminology associated with this document, the description, definition, and / or terminology used in this document shall control.

[0143] Finally, it should be understood that the embodiments described in this application are only used to illustrate the principles of the embodiments of the present application. Other variations may also fall within the scope of the present application. Therefore, as an example and not a limitation, the alternative configurations of the embodiments of the present application may be considered to be consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly introduced and described in the present application.

Claims

1. A radiotherapy system, comprising: a magnetic resonance imaging device configured to acquire magnetic resonance imaging data relating to a region of interest of a subject, the magnetic resonance imaging device comprising a magnet; as well as A radiotherapy device configured to apply a radiation beam to at least a portion of the region of interest, the radiotherapy device comprising: A linear accelerator configured to accelerate electrons to generate the radiation beam, the linear accelerator being located in a chamber formed by the inner surface of the magnet, and the length direction of the linear accelerator being parallel to the axis of the magnet; The magnetic resonance imaging apparatus further comprises one or more gradient coils disposed in the chamber, wherein the one or more gradient coils are split gradient coils; The linear accelerator is located in a gap between two adjacent split gradient coils.

2. The radiotherapy system according to claim 1, characterized in that The one or more gradient coils surround the axis of the magnet.

3. The radiation therapy system according to claim 1, characterized in that The linear accelerator is disposed in an opening formed by the inner surface of the one or more gradient coils.

4. The radiation therapy system according to claim 3, characterized in that The linear accelerator is disposed at or near an end of the chamber.

5. The radiation therapy system according to claim 3, characterized in that The radiotherapy apparatus also includes an annular radiation shielding assembly surrounding the linear accelerator.

6. The radiation therapy system according to claim 1, characterized in that The linear accelerator is disposed at or near a midpoint of the chamber in a length direction of the chamber.

7. The radiation therapy system according to claim 1, characterized in that The radiotherapy apparatus further includes a radiation shielding assembly surrounding a portion of the linear accelerator, wherein the surrounding portion of the linear accelerator is closer to the axis of the magnet.

8. The radiation therapy system according to claim 1, characterized in that The radiotherapy device also includes: At least one deflection magnet is configured to deflect the electrons toward a target, generating the radiation beam when the electrons collide with the target.

9. The radiation therapy system according to claim 8, characterized in that A distance between the target and the axis of the magnet is greater than a distance between the linear accelerator and the axis of the magnet.

10. The radiation therapy system according to claim 9, characterized in that The linear accelerator is located away from a path of the radiation beam from the target to at least a portion of the region of interest.

11. The radiation therapy system according to claim 9, characterized in that The linear accelerator is located at a first position corresponding to a first circumferential angle of the chamber, and the target is located at a second position corresponding to a second circumferential angle of the chamber, wherein the first circumferential angle is not equal to the second circumferential angle.

12. The radiation therapy system according to claim 8, characterized in that The at least one deflection magnet comprises a permanent magnet.

13. The radiation therapy system according to claim 1, characterized in that The radiotherapy apparatus includes a microwave assembly configured to accelerate electrons, the microwave assembly being operably coupled to the linear accelerator via a waveguide.

14. The radiotherapy system according to any one of claims 1 to 13, characterized in that: The magnet comprises: at least two main magnetic coils; at least two shielding coils, the at least two shielding magnetic coils surrounding the axis of the magnet and arranged along a circumference or a portion thereof, and the at least two shielding magnetic coils are at a larger radius from the axis of the magnet than the at least two main magnetic coils; and An annular cryostat is provided, wherein the at least two main magnetic coils and the at least two shielding coils are arranged.

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