System and method for imaging moving objects

Abstract

The present application provides a system and method for imaging a moving object. The method may include determining an axial extent of a region of interest (ROI) of the object; determining at least two axial positions of a radiation source relative to the object; and causing the radiation source to emit a radiation beam toward the ROI at each of the at least two axial positions relative to the object to generate an image frame of the ROI. The radiation beams corresponding to the at least two axial positions may collectively cover the axial extent of the ROI. The method may further include determining an axial position of the ROI to receive radiation therapy based on the image frame of the ROI.

Description

[0001] Priority and divisional declarations

[0002] This application is a divisional application of the Chinese application with application date of September 23, 2020, application number 202011009214.7, and invention name “System and method for imaging moving objects”, which is based on and claims priority of U.S. application No. 16 / 708,568 filed on December 10, 2019, and all contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates generally to systems and methods for imaging, and more particularly to systems and methods for imaging moving objects. Background Art

[0004] Imaging techniques (e.g., CT imaging) have been widely used in the medical field. In applications involving moving objects (e.g., radiation therapy (RT)), imaging can be used to determine the range of motion of the treatment target and / or organs at risk (OARs) for radiation damage before treatment. Typically, treatment is planned so that the treatment beam is applied only during a portion of the motion cycle (e.g., 80% to 100% of a complete exhalation in the respiratory cycle). It is very important that before treatment is performed on a particular day, the portion of the motion cycle should be set up that corresponds to the motion state in which the treatment target is in the planned position. Therefore, it is desirable to provide a method and system for imaging a moving object in a more optimal manner so that the full range of motion information is included in the image. Summary of the Invention

[0005] According to one aspect of the present application, a method is provided. The method may be implemented on a computing device having at least one storage device storing a set of instructions and at least one processor in communication with the at least one storage device. The method may include determining an axial range of motion of a region of interest (ROI) of a subject. The ROI may move due to physiological motion of the subject. The method may further include dividing the physiological motion into at least two time bins. The method may further include, in at least one of the at least two time bins, determining at least two axial positions of a radiation source relative to the subject, and causing the radiation source to emit a radiation beam toward the ROI at each of the at least two axial positions relative to the subject to generate an image frame of the ROI. The radiation beams corresponding to the at least two axial positions may collectively cover the axial range of motion of the ROI. The method may further include, for each of the at least two time bins, determining the axial position of the ROI based on the image frame of the ROI generated in the corresponding time bin. The method may also include determining, based on the axial position of the ROI, at least one time bin in the at least two time bins in which a treatment beam is to be emitted toward the ROI.

[0006] According to one aspect of the present application, a system is provided. The system may include at least one storage medium and at least one processor. The storage medium may include a set of instructions. The processor may communicate with the at least one storage medium. When executing the instructions, the at least one processor is configured to cause the system to perform operations. The operations may include determining an axial range of motion of a region of interest (ROI) of an object. The ROI may move due to physiological motion of the object. The operations may further include dividing the physiological motion into at least two time bins. The operations may further include, in at least one of the at least two time bins, determining at least two axial positions of a radiation source relative to the object, and causing the radiation source to emit a radiation beam toward the ROI at each of the at least two axial positions relative to the object to generate an image frame of the ROI. The radiation beams corresponding to the at least two axial positions may collectively cover the axial range of motion of the ROI. The operations may further include, for each of the at least two time bins, determining the axial position of the ROI based on the image frame of the ROI generated in the corresponding time bin. And the operation may further include determining at least one time bin in which a treatment beam is to be emitted to the region of interest, among the at least two time bins, based on the position of the region of interest in the axial direction.

[0007] In some embodiments, determining the axial movement range of the region of interest of the object may include acquiring an image of the object based on scanning of the object, identifying the region of interest in the image of the object; and determining the movement range of the region of interest based on the identified region of interest.

[0008] In some embodiments, the physiological motion of the subject may include at least one of respiratory motion or cardiac motion of the subject.

[0009] In some embodiments, the radiation source can generate X-rays having at least two different energy spectra.

[0010] In some embodiments, dividing the physiological movement into at least two time bins may include acquiring a time-varying motion signal representing the physiological movement through a sensor connected to the object; and dividing the time-varying motion signal into at least two segments, each of the at least two segments corresponding to one of the at least two time bins.

[0011] In some embodiments, determining at least two axial positions of the radiation source relative to the object may include determining the axial coverage of the radiation beam of the radiation source; and determining the at least two axial positions of the radiation source so that the range of motion of the region of interest in the axial direction is within a combination of the axial coverage of the radiation source at the at least two axial positions relative to the object.

[0012] In some embodiments, the object may be supported by a table movable in the axial direction. The causing the radiation source to emit a radiation beam toward the region of interest at each of the at least two axial positions relative to the object to generate an image frame of the region of interest may include moving the table to a table position so that the radiation source is located at one of the at least two axial positions relative to the object; and causing the radiation source to emit the radiation beam toward the region of interest when the table is located at the table position.

[0013] In some embodiments, the radiation source may be mounted on a gantry movable along the axial direction. The step of causing the radiation source to emit a radiation beam toward the region of interest at each of the at least two axial positions relative to the object to generate an image frame of the region of interest may include moving the gantry to a gantry position such that the radiation source is located at one of the at least two axial positions relative to the object; and causing the radiation source to emit the radiation beam toward the region of interest when the gantry is in the gantry position.

[0014] In some embodiments, determining at least one time bin in which a treatment beam is to be emitted to the region of interest among the at least two time bins based on the position of the region of interest in the axial direction may include obtaining a planned position of the region of interest at which the treatment beam is to be emitted; determining at least one position of the region of interest among the positions of the region of interest in the axial direction, the position matching the planned position of the region of interest at which the treatment beam is to be emitted; and determining the at least one time bin based on the at least one matching position of the region of interest.

[0015] In some embodiments, the method may further comprise tracking the motion of the region of interest.Determining at least two axial positions of the radiation source relative to the object may comprise determining the at least two axial positions relative to the object based on the tracked motion of the region of interest.

[0016] In some embodiments, causing the radiation source to emit a radiation beam to the region of interest at each of the at least two axial positions relative to the object to generate an image frame of the region of interest may include causing the radiation source to emit the radiation beam to the region of interest from one or more angles at each of the at least two axial positions relative to the object, the one or more angles being the angles at which the treatment beam is to be emitted to the region of interest.

[0017] Some additional features of the present application may be explained 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 accompanying drawings, or through understanding 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

[0018] The present application will be further described by way of exemplary embodiments. These exemplary embodiments will be described in detail with reference to the accompanying drawings. The drawings are not drawn to scale. These embodiments are non-limiting exemplary embodiments, in which like numbers in the various figures represent similar structures, wherein:

[0019] Figure 1 is a schematic diagram of an exemplary imaging system according to some embodiments of the present application;

[0020] Figure 2 is a schematic diagram of an exemplary computing device according to some embodiments of the present application, on which at least a portion of the imaging system 100 may be implemented;

[0021] Figure 3 is a schematic diagram of hardware and / or software components of an exemplary mobile device according to some embodiments of the present application;

[0022] Figure 4 is a block diagram of an exemplary processing device according to some embodiments of the present application;

[0023] Figure 5 is a flow chart of an exemplary process for determining at least one time bin in which a treatment beam is to be transmitted to a region of interest (ROI) according to some embodiments of the present application;

[0024] Figure 6 is a flowchart of an exemplary process for determining a motion range of a region of interest according to some embodiments of the present application;

[0025] Figure 7is a flowchart of an exemplary process for dividing a time-varying motion signal according to some embodiments of the present application;

[0026] Figure 8 is a flow chart of an exemplary process for determining at least two axial positions of a radiation source according to some embodiments of the present application;

[0027] Figure 9 is a flowchart of an exemplary process for causing a radiation source to emit a radiation beam according to some embodiments of the present application;

[0028] Figure 10 is a flowchart of another exemplary process for causing a radiation source to emit a radiation beam according to some embodiments of the present application; and

[0029] Figure 11 is a flowchart of an exemplary process for determining at least one time bin 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, a brief introduction to the drawings required for use in the description of the embodiments will be given 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 various aspects of the present application, well-known methods, processes, systems, components and / or circuits have been described at a higher level. It is obvious to those skilled in the art that various changes can be made to the disclosed embodiments, and the general principles defined in the present application can be applied to other embodiments and application scenarios without departing from the principles and scope of the present application. Therefore, the present application is not limited to the embodiments shown, but conforms to the broadest scope consistent with the scope of the patent application.

[0031] It will be understood that the terms "system," "engine," "unit," "module," and / or "block" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels in ascending order. However, these terms may be replaced by other expressions if they achieve the same purpose.

[0032] Generally, the words "module," "unit," or "block" as used herein refer to a collection of logic or software instructions embodied in hardware or firmware. The modules, units, or blocks described herein may be implemented as software and / or hardware and may be stored in any type of non-transitory computer-readable medium or another storage device. In some embodiments, software modules / units / blocks may be compiled and linked into an executable program. It will be appreciated that a software module may be callable from other modules / units / blocks or from itself, and / or may be called in response to a detected event or interrupt. A software module / unit / block configured to execute on a computing device (e.g., such as Figure 2 The processor 210 shown) can be provided on a computer-readable medium, such as an optical disc, a digital video disc, a flash drive, a magnetic disk, or any other tangible medium, or as a digital download (and can be initially stored in a compressed or installable format that requires installation, decompression, or decryption before execution). Such software code can be stored in part or in whole on a storage device of the executing computing device and applied in the operation of the computing device. The software instructions can be embedded in firmware, such as an EPROM. It will also be appreciated that hardware modules / units / blocks can be included in connected logical components, such as gates and triggers, and / or can be included in programmable units, such as programmable gate arrays or processors. The modules / units / blocks or computing device functions described herein can be implemented as software modules / units / blocks, and can also be represented in hardware or firmware. In general, the modules / units / blocks described herein can be combined with other modules / units / blocks, or although they are physically organized or stored, they can also be divided into sub-modules / sub-units / sub-blocks. This description can apply to a system, an engine, or a portion thereof.

[0033] It will be understood that when a unit, engine, module, or block is referred to as being "on," "connected," or "coupled to" another unit, engine, module, or block, it can be directly on, connected, coupled, or in communication with the other unit, engine, module, or block, or there can be intervening units, engines, modules, or blocks, unless the context clearly indicates otherwise. In this application, the term "and / or" may include any one or more of the relevant listed items or any combination thereof.

[0034] The terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. As used herein, the singular forms "a", "an", and "the" may also include the plural forms unless the context clearly indicates an exception. It should also be understood that the terms "comprises" and "includes" used in this application only indicate the presence of the features, wholes, steps, operations, components and / or parts, but do not exclude the presence or addition of at least one other feature, whole, step, operation, component, part and / or combination thereof.

[0035] Provided herein are systems and methods for imaging, such as for disease diagnosis, physical examination, or disease treatment. For example, the imaging system and method provided in this application can be used for internal inspection (e.g., non-invasive internal inspection), including, internal inspection of the anatomical structure of one or more tissues or organs, the metabolism of one or more tissues or organs, the function of one or more tissues or organs. The imaging system can be applied in different fields except the medical field. For example, the imaging system can be used for internal inspection (e.g., non-invasive internal inspection) of one or more components. For example, the imaging system and method provided in this application can be used for defect detection of components of a machine, security scanning of luggage, fault analysis, metrology, component analysis, gap detection, wall thickness assessment, etc., or any combination thereof.

[0036] Some embodiments of the present application provide systems and methods for imaging a moving region of interest in a subject. In some embodiments, the moving region of interest may move due to physiological motion of the subject. The method may include determining the range of motion of the axially moving region of interest. The method may further include dividing the physiological motion of the subject into at least two time bins. In at least one of the at least two time bins, a radiation source may emit a radiation beam toward the region of interest at at least two axial positions relative to the subject to generate image frames of the region of interest. In this case, regardless of the movement of the region of interest, the radiation beams emitted from the radiation source at the at least two axial positions may collectively cover the axial extent of the region of interest. To this end, in some embodiments, the method may include causing the radiation source to exhaustively scan the region of interest so that, in each time bin, the radiation beam consistently covers the range of motion of the axially moving region of interest. In some alternative embodiments, the method may include causing the radiation source to actively track the axial extent of the region of interest in real time, and in each time bin, the radiation beam may cover the tracked axial extent of the region of interest. The method may then include determining, for each of the at least two time bins, the axial position of the region of interest based on the image frames of the region of interest generated in the corresponding time bin. The method may further include determining, based on the position of the region of interest in the axial direction, at least one time bin in which the treatment beam is to be emitted to the region of interest among the at least two time bins.

[0037] The following description is intended to facilitate a better understanding of the method and / or system for imaging a region of interest in motion. The term "image" as used in this application may refer to a two-dimensional image, a three-dimensional image, a four-dimensional image, and / or any related image data (e.g., projection data and / or corresponding image data). The image data may correspond to a distribution of the degree of absorption of a radiation beam by different anatomical structures of an object (e.g., a patient). The projection data corresponding to the image data may refer to the sum or line integral of linear attenuation coefficients along at least two radiation beam directions.

[0038] The following description of the CT imaging system is provided for illustrative purposes. It should be understood that it is not intended to limit the scope of this application. Those skilled in the art may make certain variations, modifications, and / or alterations under the guidance of the present invention. Such variations, modifications, and / or alterations do not depart from the scope of this application.

[0039] Figure 1 FIG2 is a schematic diagram of an exemplary imaging system 100 according to some embodiments of the present application. The imaging system 100 may include an imaging device 110 , a network 120 , one or more terminals 130 , a processing device 140 , and a storage device 150 .

[0040] The imaging device 110 may be a computed tomography (CT) imaging device. The imaging device 110 may include a gantry 113, a detector 112, a table 114, and a scan source 115. The gantry 113 may support the detector 112 and the scan source 115. An object may be placed on the table 114 for scanning. The scan source 115 may emit X-rays toward the object. The detector 112 may detect attenuated X-rays. The attenuated X-rays may be further processed and converted into image data for image reconstruction. By way of example only, referring to the imaging system 100, the X-rays may be generated by the scan source 115 based on the Bremsstrahlung principle. The detector 112 may include a semiconductor detector, a gas detector, or a scintillation detector. In some embodiments, the detector 112 may include at least two detector units, which may be arranged in any suitable manner. For example, the at least two detector units may be arranged on a flat surface, and the detector 112 may be a flat panel detector. For another example, the at least two detector units may be arranged on a curved surface, and the detector 112 may be a curved detector.

[0041] In some embodiments, a therapeutic device (not shown) can be added to the imaging system 100. The therapeutic device may include a therapeutic radiation source, a gantry, a collimator, etc., or a combination thereof. The therapeutic radiation source may be a linear accelerator (LINAC). The collimator can control the shape of the radiation generated by the therapeutic radiation source. In some embodiments, the imaging device 110 and the therapeutic device can share a gantry. For example, the therapeutic radiation source can be mounted on the gantry 113. The object can be placed on the workbench 114 for treatment and / or scanning. By way of example only, the imaging system 100 can be an RT-CT system. The imaging device 110 described herein can be applied to object positioning and / or authentication in image-guided radiation therapy (IGRT). Based on image data processed / converted from the attenuated X-rays detected by the detector 112 of the imaging device 110, an image for guiding the treatment beam can be generated.

[0042] The network 120 may include any suitable network that can facilitate the exchange of information and / or data for the imaging system 100. In some embodiments, one or more components of the imaging system 100 (e.g., the imaging device 110, the terminal 130, the processing device 140, the storage device 150, etc.) can exchange information and / or data with one or more other components of the imaging system 100 or an external device (e.g., an external storage device) via the network 120. For example, the processing device 140 can obtain projection data from the imaging device 110 via the network 120. For another example, the processing device 140 can obtain user instructions from the terminal 130 via the network 120. The network 120 may be and / or 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., a wireless LAN), Ethernet, a wireless network (e.g., a 702.11 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, and / or any combination thereof. By way of example only, the network 120 may include a cable network, a wired network, a fiber optic network, a telecommunications network, an intranet, a wireless local area network (WLAN), a metropolitan area network (MAN), a public switched telephone network (PSTN), a Bluetooth TM Network, ZigBee TM In some embodiments, the network 120 may include a wireless network, a near field communication (NFC) network, or any combination thereof. In some embodiments, the network 120 may include one or more network access points. For example, the network 120 may include a wired and / or wireless network access point such as a base station and / or an Internet exchange point, through which one or more components of the imaging system 100 may be connected to the network 120 to exchange data and / or information.

[0043] The terminal 130 may include a mobile device 131, a tablet computer 132, a laptop computer 133, etc., or any combination thereof. In some embodiments, the mobile device 131 may include a smart home device, a wearable device, a smart mobile device, a virtual reality device, an augmented reality device, etc., or any combination thereof. For example only, the terminal 130 may include Figure 3 The mobile device shown. In some embodiments, smart home devices may include smart lighting devices, smart appliance control devices, smart monitoring devices, smart TVs, smart cameras, intercoms, etc., or any combination thereof. In some embodiments, wearable devices may include bracelets, shoes, glasses, helmets, watches, clothes, backpacks, smart accessories, etc., or any combination thereof. In some embodiments, mobile devices may include mobile phones, personal digital assistants (PDAs), gaming devices, navigation devices, POS machines, laptops, tablet computers, desktops, etc., or any combination thereof. In some embodiments, virtual reality devices and / or augmented reality devices may include virtual reality helmets, virtual reality glasses, virtual reality goggles, augmented reality helmets, augmented reality glasses, augmented reality goggles, etc., or any combination thereof. For example, virtual reality devices and / or augmented reality devices may include Google Glass TM 、Oculus Rift TM 、Hololens TM 、Gear VR TM In some embodiments, the terminal 130 may be part of the processing device 140 .

[0044] The processing device 140 can process data, images and / or information obtained from the imaging device 110, the terminal 130, the storage device 150, the external device, etc. In some embodiments, the processing device 140 can be a single server or a server group. The server group can be centralized or distributed. In some embodiments, the processing device 140 can be local or remote to other components of the imaging system 100 (e.g., the imaging device 110). For example, the processing device 140 can access data, images and / or information stored in the imaging device 110, the terminal 130, the storage device 150, the external device, etc. via the network 120. For another example, the processing device 140 can be directly connected to the imaging device 110, the terminal 130 and / or the storage device 150 to access the stored data, images and / or information. In some embodiments, the processing device 140 can be implemented on a cloud platform. By way of example only, the cloud platform can include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-layer cloud, etc., or any combination thereof. In some embodiments, the processing device 140 can be provided by a system having a plurality of computer systems such as: Figure 2 The computing device 200 implements one or more of the components shown.

[0045] The storage device 150 can store data, instructions, and / or any other information. In some embodiments, the storage device 150 can store data obtained from the terminal 130 and / or the processing device 140. In some embodiments, the storage device 150 can store data and / or instructions that the processing device 140 can execute or use to execute the exemplary methods described in this application. In some embodiments, the storage device 150 can include a mass storage device, a removable storage device, a volatile read-write memory, a read-only memory (ROM), or the like, or any combination thereof. Exemplary mass storage devices can include magnetic disks, optical disks, solid-state drives, or the like. Exemplary removable storage devices can include flash drives, floppy disks, optical disks, memory cards, compact disks, magnetic tapes, or the like. Exemplary volatile read-write memory devices can include random access memory (RAM). Exemplary RAM devices can include dynamic random access memory (DRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), static random access memory (SRAM), thyristor random access memory (T-RAM), and zero-capacitance random access memory (Z-RAM). Exemplary ROMs may include mask ROM (MROM), programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), compact disc ROM (CD-ROM), and digital versatile disk ROM. In some embodiments, the storage device 150 may be implemented on a cloud platform. By way of example only, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-layer cloud, or any combination thereof.

[0046] In some embodiments, the storage device 150 can be connected to the network 120 to communicate with one or more other components of the imaging system 100 (e.g., the processing device 140, the terminal 130). One or more components of the imaging system 100 can access data or instructions stored in the storage device 150 via the network 120. In some embodiments, the storage device 150 can be directly connected to or communicate with one or more other components of the imaging system 100 (e.g., the processing device 140, the terminal 130). In some embodiments, the storage device 150 can be part of the processing device 140.

[0047] Figure 2 FIG. 2 is a schematic diagram of an exemplary computing device 200 according to some embodiments of the present application, on which at least a portion of the imaging system 100 may be implemented. Figure 2 As shown, computing device 200 may include processor 210 , memory 220 , input / output (I / O) 230 , and communication port 240 .

[0048] The processor 210 can execute computer instructions (e.g., program code) and perform the functions of the processing device 140 according to the techniques described herein. Computer instructions may include, for example, routines, programs, objects, components, data structures, processes, modules, and functions that perform the specific functions described herein. For example, the processor 210 can process motion data acquired from the imaging device 110, the terminal 130, the storage device 150, and / or any other component of the imaging system 100. For another example, the processor 210 can process images acquired from the terminal 130, the storage device 150, and / or any other component of the imaging system 100. In some embodiments, the processor 210 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 of the above functions, or a combination thereof.

[0049] For illustrative purposes only, only one processor is described in computing device 200. However, it should be noted that computing device 200 in the present application may also include multiple processors. Therefore, operations and / or method steps performed by one processor as described in the present application may also be performed jointly or separately by multiple processors. For example, if in the present application, a processor of computing device 200 performs operation A and operation B simultaneously, it should be understood that operation A and operation B may also be performed jointly or separately by two or more different processors in computing device 200 (e.g., a first processor performs operation A, a second processor performs operation B, or the first processor and the second processor perform operations A and B together).

[0050] The memory 220 can store data / information acquired from the imaging device 110, the terminal 130, the storage device 150, and / or any other components of the imaging system 100, external devices, and the like. In some embodiments, the memory 220 may include a mass storage device, a removable storage device, volatile read-write memory, read-only memory (ROM), or a combination thereof. For example, the mass storage device may include a magnetic disk, an optical disk, a solid-state drive, or the like. The removable storage device may include a flash drive, a floppy disk, an optical disk, a memory card, a compact disk, a magnetic tape, or the like. The volatile read-write memory may include random access memory (RAM). The RAM may include dynamic RAM (DRAM), double data rate synchronous dynamic RAM (DDR SDRAM), static RAM (SRAM), thyristor RAM (T-RAM), and zero-capacitor RAM (Z-RAM). ROM may include mask ROM (MROM), programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), compact disk ROM (CD-ROM), and digital versatile disk ROM. In some embodiments, the memory 220 may store one or more programs and / or instructions for executing the exemplary methods described herein. For example, the memory 220 may store a program for the processing device 140 for imaging and / or determining at least one time bin in which to transmit a treatment beam to a region of interest.

[0051] The I / O 230 may input and / or output signals, data, information, and the like. In some embodiments, the I / O 230 may enable a user to interact with the processing device 140. In some embodiments, the I / O 230 may include input devices and output devices. Examples of input devices may include a keyboard, a mouse, a touch screen, a microphone, or the like, or a combination thereof. Examples of output devices may include a display device, a speaker, a printer, a projector, or the like, or a combination thereof. Examples of display devices may include a liquid crystal display (LCD), a light emitting diode (LED)-based display, a flat panel display, a curved screen, a television device, a cathode ray tube (CRT), a touch screen screen, or the like, or a combination thereof.

[0052] The communication port 240 can be connected to a network (e.g., network 120) to facilitate data communication. The communication port 240 can establish a connection between the processing device 140 and the imaging device 110, the terminal 130, and / or the storage device 150. The connection can be a wired connection, a wireless connection, any other communication connection that can enable data transmission and / or reception, and / or a combination of these connections. The wired connection can include, for example, an electrical cable, an optical cable, a telephone line, etc., or a combination thereof. The wireless connection can include, for example, a Bluetooth® wireless connection. TM Link, Wi-Fi TM Link, WiMax TMIn some embodiments, the communication port 240 may be a wireless communication port, a WLAN link, a ZigBee link, a mobile network link (e.g., 3G, 4G, 5G, etc.), or a combination thereof. In some embodiments, the communication port 240 may be and / or include a standardized communication port, such as RS232, RS485, etc. In some embodiments, the communication port 240 may be a specially designed communication port. For example, the communication port 240 may be designed according to the Digital Imaging and Communications in Medicine (DICOM) protocol.

[0053] Figure 3 FIG. 1 is a diagram illustrating exemplary hardware and / or software components of an exemplary mobile device 300 according to some embodiments of the present application, on which the terminal 130 may be implemented. Figure 3 As shown, mobile device 300 may include a communication platform 310, a display 320, a graphics processing unit (GPU) 330, a central processing unit (CPU) 340, an I / O 350, a memory 360, and a storage 390. In some embodiments, any other suitable components, including but not limited to a system bus or controller (not shown), may also be included in mobile device 300. In some embodiments, a mobile operating system 370 (e.g., iOS 11) may be used. TM 、Android TM 、Windows Phone TM ) and one or more applications 380 are loaded from storage 390 into memory 360 for execution by CPU 340. Applications 380 may include a browser or any other suitable mobile application for receiving and rendering information related to image processing or other information from processing device 140. User interaction with the information stream may be enabled via I / O 350, and may be provided to processing device 140 and / or other components of imaging system 100 via network 120.

[0054] To implement the various modules, units, and functions described herein, a computer hardware platform may be used as the hardware platform for one or more of the components described herein. A computer with a user interface device may be used to implement a personal computer (PC) or any other type of workstation or terminal device. If the computer is appropriately programmed, the computer may also be used as a server.

[0055] Figure 4 FIG1 is a block diagram of an exemplary processing device 140 according to some embodiments of the present application. The processing device 140 may include a motion range determination module 410, a physiological motion classification module 420, an axial position determination module 430, a radiation beam emission module 440, a region of interest position determination module 450, and a time bin determination module 460.

[0056] The processing device 140 may be implemented on various components (e.g., Figure 2 The computing device 200 shown, Figure 3 The mobile device 300 shown is implemented.

[0057] The motion range determination module 410 can be configured to determine the motion range of a region of interest (ROI) of the object in the axial direction. In some embodiments, the region of interest may refer to a body part of the object that is assumed to be irradiated and / or treated by the treatment beam during treatment. In some embodiments, the region of interest may move due to the physiological movement of the object. The motion range of the region of interest in the axial direction may refer to the entire motion range of the region of interest in the axial direction during the entire cycle of the physiological movement. In some embodiments, the motion range of the region of interest in the axial direction may be expressed in a coordinate system. In some embodiments, in order to determine the motion range of the region of interest of the object in the axial direction, the motion range determination module 410 can be configured to acquire an image of the object based on a scan of the object, identify the region of interest in the image of the object, and determine the motion range of the region of interest based on the identified region of interest.

[0058] The physiological motion segmentation module 420 can be configured to segment the physiological motion into at least two time bins. In some embodiments, each of the at least two time bins can be short enough so that the region of interest of the subject can be considered static or approximately static in each of the at least two time bins. For each of the at least two time bins, data acquired therein can be used to reconstruct an image, which can be used to provide information about the region of interest in the corresponding time bin. In some embodiments, to segment the physiological motion into at least two time bins, the physiological motion segmentation module 420 can be configured to acquire a time-varying motion signal representing the physiological motion through a sensor connected to the subject, and segment the time-varying motion signal into at least two segments.

[0059] The axial position determination module 430 can be configured to determine at least two axial positions of the radiation source relative to the object. In some embodiments, the radiation source can generate X-rays having at least two different energy spectra. In some embodiments, to determine the at least two axial positions relative to the object, the axial position determination module 430 can be configured to determine the axial coverage of the radiation beam of the radiation source, and to determine the at least two axial positions of the radiation source. Therefore, the axial motion range of the region of interest is within the combination of the axial coverage of the radiation source at the at least two axial positions relative to the object. In some embodiments, to determine the at least two axial positions relative to the object, the axial position determination module 430 can also be configured to track the motion of the region of interest in real time, and to determine the at least two axial positions relative to the object based on the real-time axial range of the region of interest.

[0060] The radiation beam emission module 440 can be configured to cause the radiation source to emit a radiation beam toward the region of interest at each of at least two axial positions relative to the subject to generate an image frame of the region of interest. In some embodiments, the subject can be supported by an axially movable table. The radiation beam emission module 440 can be configured to move the table to a table position such that the radiation source is at one of the at least two axial positions relative to the subject, and when the table is in the table position, cause the radiation source to emit the radiation beam toward the region of interest. In some embodiments, the radiation source can be mounted on an axially movable gantry. The radiation beam emission module 440 can be configured to move the gantry to a gantry position such that the radiation source is at one of the at least two axial positions relative to the subject, and when the gantry is in the gantry position, cause the radiation source to emit the radiation beam toward the region of interest. In some embodiments, the radiation beam emission module 440 can be configured to cause the radiation source to emit a radiation beam toward the region of interest at each of the at least two axial positions relative to the subject at one or more angles, wherein the one or more angles are angles at which the treatment beam is to be emitted toward the region of interest. In this way, the motion trajectory of the region of interest can be most relevantly determined from viewpoints corresponding to one or more angles of planned treatment beam entry.

[0061] The region of interest position determination module 450 may be configured to determine, for each of the at least two time bins, the axial position of the region of interest based on the image frames of the region of interest generated in the corresponding time bin. In some embodiments, for each of the at least two time bins, the region of interest position determination module 450 may be configured to identify the region of interest in each image frame of the region of interest generated in the corresponding time bin. Optionally, the region of interest position determination module 450 may be configured to synthesize at least two image frames generated in the same time bin to obtain a composite image representing the entire region of interest, and then identify the entire region of interest in the composite image. In some embodiments, the region of interest position determination module 450 may be further configured to determine the position of the region of interest based on the region of interest identified in each image frame.

[0062] The time bin determination module 460 may be configured to determine, based on the position of the region of interest, at least one time bin in which the treatment beam is to be transmitted to the region of interest from among the at least two time bins. In some embodiments, to determine the at least one time bin, the time bin determination module 460 may be configured to obtain a planned position of the region of interest at which the treatment beam is to be transmitted; determine at least one position of the region of interest from among the positions of the region of interest that matches the planned position of the region of interest at which the treatment beam is to be transmitted; and determine at least one time bin based on the at least one matched position of the region of interest.

[0063] It should be noted that the description of the processing device 140 provided above is for illustrative purposes and is not intended to limit the scope of the present application. For those of ordinary skill in the art, various modifications and changes can be made to the application form and details of the above-mentioned method and system without departing from the principles of the present application. As an example only, the processing device 140 may include one or more other modules. However, those changes and modifications also fall within the scope of the present application.

[0064] Figure 5 FIG. 5 is a flow chart of an exemplary process 500 for determining at least one time bin in which a treatment beam is to be transmitted to a region of interest according to some embodiments of the present application. In some embodiments, at least a portion of the process 500 may be performed by the processing device 140 (e.g., in FIG. 5 ). Figure 2 For example, process 500 may be stored in a storage device (e.g., storage device 150, memory 220, memory 390) in the form of instructions (e.g., an application program) and executed by processing device 140 (e.g., Figure 2 The processor 210 shown, Figure 3 The CPU 340 or Figure 4 The operations of the process shown below are for illustration purposes only. In some embodiments, process 500 may be accomplished using one or more additional operations not described and / or one or more operations not discussed. Figure 5 The order in which the operations of process 500 are illustrated and described below is not intended to be limiting.

[0065] In 502 , the processing device 140 (eg, the motion range determination module 410 ) may determine a motion range of a region of interest (ROI) of an object in an axial direction.

[0066] In some embodiments, the object can be biological or non-biological. By way of example only, the object can include a patient, an artificial object, etc. For another example, the object can include a specific part, organ, and / or tissue of a patient. Specifically, the object can include the patient's head, brain, neck, body, shoulder, arm, chest, heart, stomach, blood vessels, soft tissue, knee, foot, etc., or any combination thereof. In some embodiments, a region of interest (ROI) can refer to a body part (e.g., a tissue, an organ, a portion of a tissue, a portion of an organ, etc.) of the object that is assumed to be irradiated and / or treated by the treatment beam during treatment. For illustrative purposes, assuming that the object is a patient, the region of interest can be a tumor on a specific organ of the patient that will be irradiated and / or treated by the treatment beam.

[0067] In some embodiments, the region of interest may move due to physiological motion of the subject. Exemplary physiological motion of the subject may include respiratory motion or cardiac motion of the subject. As just one example, due to cardiac motion, the region of interest on the heart or an organ near the heart (e.g., the left lung) may move with the beating of the heart. For another example, due to respiratory motion, the region of interest on the lung may be located at different positions at different stages of the respiratory state (e.g., expiratory state, inspiratory state).

[0068] The axial range of motion of the region of interest can refer to the entire axial range of motion of the region of interest during the entire cycle of physiological motion. Axial can refer to the direction of relative motion between the scan source 115 and the patient during scanning, which is the same as the direction from the head to the feet when the patient is lying on the workbench 114 for scanning. The range of motion of the region of interest can be determined so that at any point in time during the entire cycle of physiological motion, any part of the region of interest is within the range of motion of the region of interest. In some embodiments, the processing device 140 (e.g., the range of motion determination module 410) can determine a coordinate system for representing the axial range of motion of the region of interest. The coordinate system can have any number of dimensions, and the dimensions can be in any direction. Exemplary coordinate systems can include a three-dimensional world coordinate system, an image coordinate system, etc., or any combination thereof. The coordinate origin of the coordinate system can be located at any suitable location. For example, the coordinate origin of the world coordinate system can be located at the isocenter of the imaging device 110.

[0069] In some embodiments, the processing device 140 can determine the axial range of motion of the region of interest using one or more images representing the region of interest. One or more images representing the region of interest can be acquired by scanning the object using the imaging device 110 during at least one complete cycle of physiological motion. For example, the scanning source 115 can emit X-rays to scan an object (e.g., a patient's head, breast, etc.) positioned on the workbench 114. The detector 112 can detect one or more X-rays emitted from the scanning source 115 or scattered by the object to obtain projection values. Furthermore, the processing device 140 can reconstruct one or more images representing the region of interest using a reconstruction algorithm based on the projection values. Exemplary reconstruction algorithms may include iterative reconstruction algorithms (e.g., statistical reconstruction algorithms), Fourier slice theorem algorithms, fan beam reconstruction algorithms, analytical reconstruction algorithms, algebraic reconstruction techniques (ART), combined algebraic reconstruction techniques (SART), filtered back projection (FBP) techniques, Feldkamp-Davis-Kress (FDK) reconstruction techniques, or any combination thereof.

[0070] In some embodiments, the one or more images may include a three-dimensional CT image, a four-dimensional CT image, a movie image, or the like, or any combination thereof. The processing device 140 (e.g., the motion range determination module 410) may identify a region of interest in the one or more images, and further determine the motion range of the region of interest based on the identified region of interest. For example, movie imaging (or a four-dimensional CT scan) may be performed by a radiation source over at least one complete cycle of physiological motion, and the motion range of the corresponding region of interest may be identified from the movie image (or four-dimensional CT image). More description of determining the motion range of a region of interest may be found elsewhere in this application. See, for example, Figure 6 and its description.

[0071] In 504 , the processing device 140 (eg, the physiological motion segmentation module 420 ) may segment the physiological motion into at least two time bins.

[0072] In some embodiments, each of the at least two time bins can be short enough so that in each of the at least two time bins, the region of interest of the object can be considered to be static or approximately static. For each of the at least two time bins, the data (e.g., projection values) acquired therein can be used to reconstruct an image, which can be used to provide information about the region of interest in the corresponding time bin. Exemplary region of interest information can include the position of the region of interest, the outline of the region of interest, the size of the region of interest, etc., or any combination thereof. In a specific embodiment, the entire cycle of respiratory motion can typically last 2 to 6 seconds. The entire cycle of respiratory motion can be divided into, for example, 10 time bins, so each time bin can span 200 to 600 milliseconds. In each time bin, the region of interest of the object can be considered to be static or approximately static, so artifacts or blur in the image reconstructed from the data generated in the time bin can be eliminated.

[0073] In some embodiments, in order to divide the physiological motion into at least two time bins, the processing device 140 (e.g., the physiological motion division module 420) can obtain a time-varying motion signal representing the physiological motion through a sensor connected to the object, and divide the time-varying motion signal into a plurality of segments. In some alternative embodiments, the processing device 140 (e.g., the physiological motion division module 420) can extract a motion signal from a movie image or a four-dimensional CT image of the object to represent the physiological motion of the object, and divide the extracted motion signal. Each of the at least two segments can correspond to one of the at least two time bins. More description of dividing physiological motion can be found elsewhere in this application. See, for example, Figure 7 and its description.

[0074] In some embodiments, the physiological motion can be divided into at least two time bins evenly or unevenly. For example, in one cycle of respiratory motion, the respiratory motion can be evenly divided so that all time bins have the same time span (e.g., 300 milliseconds). For another example, in one cycle of respiratory motion, the respiratory motion can be unevenly divided so that the time bin corresponding to the exhalation state (e.g., 80% to 100% of full exhalation) has a larger time span than the time bin corresponding to another respiratory state (e.g., the inhalation state).

[0075] At 506 , the processing device 140 (eg, the axial position determination module 430 ) may determine at least two axial positions of the radiation source relative to the object in at least one of the at least two time bins.

[0076] In some embodiments, a radiation source (e.g., the scanning source 115 of the imaging device 110) can generate X-rays having at least two different energy spectra. Specifically, the imaging device 110 may include multi-energy CT, multi-spectral CT, etc. Multi-energy imaging can be achieved using a multi-slice detector. Multi-energy CT may include dual-energy CT that uses rapid switching of two energy spectra. Multi-spectral CT may include spectrally sensitive CT. In some embodiments, the contrast in the acquired image can be improved by scanning using a radiation source that generates X-rays having at least two different energy spectra. For example, the upper ribs can be removed (or distinguished) from a lung image acquired in dual-energy CT to better display the region of interest (e.g., a tumor) in the lung region.

[0077] In some embodiments, the axial coverage (also referred to as the axial field of view (FOV)) of the radiation beam emitted by the radiation source is not wide enough to cover the axial extent of the region of interest. In such cases, the processing device 140 may cause the radiation source to perform multiple scans at different axial positions relative to the subject, such that the axial extent of the region of interest is fully encompassed by the combined axial coverage of the radiation beam. To this end, in some embodiments, the processing device 140 (e.g., the axial position determination module 430) may determine at least two axial positions of the radiation source such that the entire axial range of motion of the region of interest is within the combination of the axial coverage of the radiation source at the at least two axial positions relative to the subject. For simplicity, a scan of the radiation source in a time bin to fully cover the entire axial range of motion of the region of interest may be referred to as an "exhaustive scan." In alternative embodiments, the processing device 140 (e.g., the axial position determination module 430) may actively track the region of interest and determine at least two axial positions of the radiation source such that the real-time axial extent of the region of interest is within the combination of the axial coverage of the radiation source at the at least two axial positions relative to the subject, where the real-time axial extent may be a portion of the entire range of motion. For simplicity, the scanning of the radiation source in one time bin to actively track and cover the real-time axial extent of the region of interest may be referred to as a "predictive scan."

[0078] In some embodiments, the at least two axial positions of the radiation source relative to the object can be changed stepwise or continuously. For example, when the radiation source emits a radiation beam in each time bin, the at least two axial positions relative to the object can be changed continuously. For another example, the at least two axial positions relative to the object can be discrete positions, and the radiation source can only emit the radiation beam when the radiation source reaches the specified position. More description of determining the axial position of the radiation source can be found elsewhere in this application. See, for example, Figure 8 and its description.

[0079] In 508 , the processing device 140 (eg, the radiation beam emission module 440 ) may cause the radiation source to emit a radiation beam toward the region of interest at each of at least two axial positions relative to the subject to generate an image frame of the region of interest.

[0080] A radiation source (e.g., scanning source 115) may include an X-ray tube that can generate X-rays using power provided by a voltage generator. Specifically, the X-ray tube may include at least an anode and a cathode. The cathode may include one or more filaments (e.g., tungsten, iridium, nickel, or molybdenum) configured to emit free electrons. The free electrons may be accelerated in an electric field between the cathode and the anode to form an electron beam that strikes the anode, thereby further generating radioactive radiation such as X-rays. The anode may be made of a conductive material that has high mechanical strength at high temperatures and a high melting point. Exemplary materials may include titanium zirconium molybdenum (TZM), iron, copper, tungsten, graphite, or alloys thereof, or any combination thereof. In a dual-energy CT system having a single radiation source (e.g., scanning source 115), the X-ray tube included in the single radiation source may generate X-rays using power provided by a voltage generator. The power provided by the voltage generator can rapidly switch between a low X-ray tube voltage and a high X-ray tube voltage, thereby generating X-rays with two different energy spectra to scan a region of interest.

[0081] In some embodiments, when the radiation source emits a radiation beam to the region of interest at each of at least two axial positions relative to the object, the detector can detect one or more X-rays emitted from the scanned source or scattered by the region of interest to obtain projection values. The projection values ​​can be sent to the processing device 140 to generate an image frame. In some embodiments, the processing device 140 can use a reconstruction algorithm based on the projection values ​​to reconstruct the image frame. Exemplary reconstruction algorithms may include iterative reconstruction algorithms (e.g., statistical reconstruction algorithms), Fourier slice theorem algorithms, fan beam reconstruction algorithms, analytical reconstruction algorithms, algebraic reconstruction techniques (ART), joint algebraic reconstruction techniques (SART), filtered back projection (FBP) techniques, Feldkamp-Davis-Kress (FDK) reconstruction techniques, etc., or any combination thereof.

[0082] In some embodiments, a radiation beam emitted by a radiation source at a specific axial position relative to the subject may cover a portion of the region of interest in the axial direction. Accordingly, an image frame corresponding to the radiation source at the specific axial position may include information about a portion of the region of interest. Radiation beams emitted by the radiation source at at least two axial positions may collectively cover the axial range of motion or the real-time axial range of the region of interest. Accordingly, image frames corresponding to the radiation source at at least two axial positions relative to the subject may collectively include all axial information about the region of interest.

[0083] In some embodiments, the subject may be supported by an axially movable table (e.g., table 114 of imaging device 110). The processing device 140 (e.g., radiation beam emission module 440) may move the table to a table position such that the radiation source is positioned at one of at least two axial positions relative to the subject. Furthermore, when the table is in the table position, the processing device 140 (e.g., radiation beam emission module 440) may further cause the radiation source to emit a radiation beam toward a region of interest. In some alternative embodiments, the radiation source may be mounted on an axially movable gantry (e.g., gantry 113 of imaging device 110). The processing device 140 (e.g., radiation beam emission module 440) may move the gantry to a gantry position such that the radiation source is positioned at one of at least two axial positions relative to the subject. Furthermore, when the gantry is in the gantry position, the processing device 140 (e.g., radiation beam emission module 440) may further cause the radiation source to emit a radiation beam toward the region of interest.

[0084] In some embodiments, the processing device 140 can cause the radiation source to emit a radiation beam to the region of interest at each of at least two axial positions relative to the object from one or more angles, wherein the one or more angles are angles at which the treatment beam is to be emitted to the region of interest. The treatment beam may include an X-ray beam, a charged particle beam, a neutron beam, an ultrasound beam, or the like, or any combination thereof. The treatment beam can be used to treat the region of interest. In some embodiments, one or more angles can be obtained from a treatment plan, in which the entry of the planned treatment beam can be predetermined. Each of the one or more angles can correspond to a discrete angle value or an angle range. In this way, the motion trajectory of the region of interest can be most relevantly determined from the field of view (beam direction view imaging) corresponding to the one or more angles of planned treatment beam entry.

[0085] In 510 , the processing device 140 (eg, the ROI position determination module 450 ) may determine, for each of the at least two time bins, a position of the ROI in the axial direction based on image frames of the ROI generated in the corresponding time bin.

[0086] In some embodiments, as shown in operation 504, each of the at least two time bins may be sufficiently short so that the region of interest of the object in each time bin may be considered static or approximately static. For each of the at least two time bins, the processing device 140 (e.g., the region of interest location determination module 450) may identify the region of interest in each image frame of the region of interest generated in the corresponding time bin. Alternatively, the processing device 140 (e.g., the region of interest location determination module 450) may synthesize at least two image frames generated in the same time bin to obtain a composite image representing the entire region of interest, and then identify the entire region of interest in the composite image. Exemplary techniques for identifying the region of interest in each image frame or in the composite image may include image segmentation techniques, manual annotation techniques, machine learning techniques, etc., or any combination thereof. In addition, based on the region of interest identified in each image frame, the processing device 140 (e.g., the region of interest location determination module 450) may determine the location of the region of interest. In some embodiments, the axial position of the region of interest can include the position of the region of interest relative to other organs / tissues in the subject, the position of the region of interest relative to a radiation source emitting a treatment beam, the position of the region of interest relative to other components of the imaging device 110 (e.g., the gantry 113), etc., or a combination thereof. The position of the region of interest can be represented using at least one set of coordinates. For example, the position of the region of interest can be represented using a world coordinate system or an image coordinate system.

[0087] In 512 , the processing device 140 (eg, the time bin determination module 460 ) may determine, based on the location of the region of interest, at least one time bin in which to transmit a treatment beam to the region of interest among the at least two time bins.

[0088] In some embodiments, the processing device 140 (e.g., the time bin determination module 460) may determine at least one time bin corresponding to a region of interest in a planned position at which a treatment beam is to be emitted. Thus, when the region of interest is moved to the planned position (e.g., a position specified in the treatment plan), the treatment beam may be emitted to the region of interest, allowing the treatment beam to be precisely emitted to the region of interest and the treatment to be precisely delivered to the region of interest. This may reduce the X-ray dose exposed to other parts of the subject (e.g., organs at risk).

[0089] Specifically, the processing device 140 (e.g., the time bin determination module 460) can obtain a planned position of the region of interest at which the treatment beam is to be emitted. The processing device 140 (e.g., the time bin determination module 460) can then determine at least one position of the region of interest among the positions of the region of interest that matches the planned position of the region of interest at which the treatment beam is to be emitted. In addition, the processing device 140 (e.g., the time bin determination module 460) can determine at least one time bin based on the at least one matching position of the region of interest. More description of determining at least one time bin can be found elsewhere in this application. See, e.g., Figure 11 and its description.

[0090] It should be noted that the description of process 500 provided above is for illustrative purposes and is not intended to limit the scope of the present application. Those skilled in the art will appreciate that various modifications and variations may be made to the application and details of the above-described methods and systems without departing from the principles of the present application. In some embodiments, process 500 may include one or more additional operations. However, such variations and modifications are also within the scope of the present application. For example, as shown in operation 502, the axial range of motion of a region of interest of an object may be determined. Those skilled in the art will appreciate that the range of motion of the region of interest may also be represented in two dimensions (e.g., axial and transverse) and / or three dimensions (axial, transverse, and vertical). For example, the processing device 140 may determine the range of motion of the region of interest in the transverse and / or vertical directions. The processing device 140 may then further determine at least two positions of the radiation source relative to the object in the transverse and / or vertical directions, such that the range of motion of the region of interest in the transverse and / or vertical directions is also fully covered by the radiation beam in each time bin. In some embodiments, by adjusting the position of the radiation source in the lateral and / or vertical directions while the radiation source is emitting a radiation beam, it may be advantageous to be able to image regions of interest near the edge of the transaxial field of view of the radiation beam.

[0091] In some embodiments, to perform a predictive scan, the processing device 140 may actively track the region of interest and determine at least two axial positions of the radiation source according to various techniques. For example, the processing device 140 may detect a motion vector between cine images of the region of interest. The processing device 140 may further input the detected motion vector into a predictor to predict the motion of the region of interest. The predicted motion may include, for example, a predicted axial position of the region of interest during a period of physiological motion. Then, in each time bin, the processing device 140 (e.g., the radiation beam emission module 440) may cause the radiation source to emit a radiation beam at at least two axial positions relative to the subject to completely cover the region of interest at the corresponding predicted axial positions to generate an image frame of the region of interest. In some embodiments, if the subject is instructed to hold their breath to a certain extent during inspiration or expiration during imaging of the region of interest, the operation of actively tracking the region of interest may be omitted because the motion of the region of interest associated with the subject holding their breath may be ignored.

[0092] For another example, surgically implanted radio frequency (RF) beacons (e.g., as used in the Calypso system) can be used to track the region of interest. For another example, an integrated magnetic resonance (MR) system can be used to provide real-time visualization of the region of interest. For another example, a radiotherapy system with an attached kilovoltage (kV) imaging system and / or megavoltage (MV) imaging system can be used to perform pre-treatment cine imaging of the region of interest to provide location information of the region of interest.

[0093] Figure 6 FIG. 6 is a flow chart of an exemplary process 600 for determining a range of motion of a region of interest according to some embodiments of the present application. In some embodiments, at least a portion of the process 600 may be performed by the processing device 140 (e.g., Figure 2 For example, process 600 may be stored in a storage device (e.g., storage device 150, memory 220, memory 390) in the form of instructions (e.g., an application program) and executed by processing device 140 (e.g., Figure 2 The processor 210 shown, Figure 3 The CPU 340 or Figure 4 The operations of the process shown below are for illustration purposes only. In some embodiments, process 600 may be accomplished using one or more additional operations not described and / or one or more operations not discussed. Figure 6 The order in which the operations of process 600 are shown and described below is not intended to be limiting. In some embodiments, operation 502 may be implemented according to process 600.

[0094] In 602 , the processing device 140 (eg, the motion range determination module 410 ) may acquire an image of an object based on a scan of the object.

[0095] In some embodiments, the processing device 140 (e.g., the motion range determination module 410) can acquire an image of the subject by performing a scout scan on the subject using the imaging device 110. For example, in any of a CT imaging system, a PET-CT imaging system, and a CT linear accelerator system, the processing device 140 can move the subject to a CT imaging position to perform the scout scan.

[0096] In some embodiments, the acquired image may be a single image frame. For example, the acquired image may include a three-dimensional CT image. A single image frame may indicate the motion state of the object at a specific point in time (e.g., the position of a region of interest in the object, the size of the region of interest in the object, or the shape of the region of interest in the object).

[0097] In some embodiments, the acquired image may include multiple image frames. For example, the acquired image may include a movie image, a four-dimensional CT image, etc., or any combination thereof. Specifically, the multiple image frames may indicate the changing motion state of the object in at least one complete cycle of the object's physiological motion (for example, the position of the region of interest in the object, the size of the region of interest in the object, the shape of the region of interest in the object). In some embodiments, the multiple image frames may be related to the physiological motion of the object. For example, the multiple image frames and the respiratory motion signal representing the physiological motion of the object can be referenced to a common time base for further processing. More description of the respiratory motion signal can be found elsewhere in this application. See, for example Figure 7 and its related descriptions.

[0098] At 604 , the processing device 140 (eg, the motion range determination module 410 ) may identify a region of interest in an image of the object.

[0099] In some embodiments, exemplary techniques for identifying regions of interest in each image frame may include image segmentation techniques, manual annotation techniques, machine learning techniques, or any combination thereof. In some embodiments, image segmentation techniques may include threshold-based segmentation techniques, region-based segmentation techniques, edge-based segmentation techniques, specific theory-based segmentation techniques, genetic algorithm-based segmentation techniques, wavelet transform-based segmentation techniques, cluster analysis-based segmentation techniques, mathematical morphology-based segmentation techniques, artificial neural network-based segmentation techniques, or any combination thereof. In some embodiments, manual annotation techniques may include manual annotation techniques and semi-manual annotation techniques. For example, in the manual annotation technique, an operator may annotate an image based on Digital Imaging and Communications in Medicine (DICOM). In some embodiments, in the machine learning technique, a trained machine learning model may be used to identify regions of interest in an image of an object. For example, an image with marked regions of interest may be used as a training sample for training a machine learning model. The trained machine learning model may then be used to identify one or more regions of interest in an input image of the object.

[0100] In some embodiments, when the acquired image includes multiple image frames, the processing device 140 may identify the region of interest in different image frames, thereby acquiring the motion states of the region of interest at different time points.

[0101] In 606 , the processing device 140 (eg, the motion range determination module 410 ) may determine a motion range of the region of interest based on the identified region of interest.

[0102] In some embodiments, the processing device 140 (e.g., the range of motion determination module 410) can determine the range of motion of the region of interest in a coordinate system. The range of motion of the region of interest can be represented using one or more coordinates in the coordinate system. For example, the range of motion of the region of interest in an axial direction can be defined by two axial coordinates. For simplicity, the two axial coordinates can be described as an upper axial coordinate and a lower axial coordinate.

[0103] In the case where the acquired image includes a plurality of image frames, the processing device 140 (e.g., the motion range determination module 410) can determine the axial position of the region of interest in each of the plurality of image frames. Then, based on the fact that all axial positions of the region of interest are always within the range defined by the upper axial coordinate and the lower axial coordinate, the processing device 140 (e.g., the motion range determination module 410) can determine the upper axial coordinate and the lower axial coordinate of the motion range of the region of interest.

[0104] In the case where the acquired image is a single image frame, the processing device 140 (e.g., the motion range determination module 410) can determine the axial position of the region of interest in the single image frame and estimate the motion range of the region of interest by, for example, expanding the range of the axial position of the region of interest in the single image frame.

[0105] It should be noted that the description of the process 600 provided above is for illustrative purposes, rather than intended to limit the scope of the application. For those of ordinary skill in the art, without departing from the principles of the application, various modifications and changes can be made to the application form and details of the above-mentioned method and system. In certain embodiments, the process 600 may include one or more other operations. However, those variations and modifications also fall within the scope of the application.

[0106] Figure 7 FIG. 7 is a flow chart of an exemplary process 700 for segmenting a time-varying motion signal according to some embodiments of the present application. In some embodiments, at least a portion of the process 700 may be performed by the processing device 140 (e.g., Figure 2 For example, process 700 may be stored in a storage device (e.g., storage device 150, memory 220, memory 390) in the form of instructions (e.g., an application program) and executed by processing device 140 (e.g., Figure 2 The processor 210 shown, Figure 3 The CPU 340 or Figure 4 The operations of the process shown below are for illustration purposes only. In some embodiments, process 700 may be accomplished using one or more additional operations not described and / or one or more operations not discussed. Figure 7 The order in which the operations of process 700 are shown and described below is not intended to be limiting. In some embodiments, operation 504 may be implemented according to process 700.

[0107] In 702 , the processing device 140 (eg, the physiological motion segmentation module 420 ) may acquire a time-varying motion signal representing physiological motion via a sensor connected to a subject.

[0108] The sensor may collect time-varying information. The time-varying signal may be related to, for example, the subject's respiratory motion, cardiac motion, etc. The processing device 140 may further analyze the time-varying information to obtain a time-varying motion signal, including, for example, a respiratory motion signal, a cardiac motion signal, etc.

[0109] In some embodiments, the sensor can be included in a motion monitoring system for monitoring the physiological motion of the subject. Exemplary motion monitoring systems may include a respiratory monitoring system, a cardiac monitoring system, or the like, or a combination thereof. Specifically, the sensor can include a motion monitoring device, such as a camera (e.g., an infrared camera), a chest strap secured around the subject's chest, or another pressure measurement technology or device to measure pressure changes during the subject's respiratory cycle.

[0110] In some embodiments, a sensor can detect motion of a subject throughout the imaging process described herein. The time-varying motion signal can be associated with one or more images of the subject. In some embodiments, the one or more images can include cine images or four-dimensional CT images of the subject. The one or more images of the subject can be associated with the time-varying motion signal such that each individual frame in the one or more images corresponds to a specific portion of the time-varying motion signal. In another embodiment, the processing device 140 can establish a relationship between the time-varying motion signal and the axial position of a region of interest in the one or more images.

[0111] In 704 , the processing device 140 (eg, the physiological motion segmentation module 420 ) may segment the time-varying motion signal into a plurality of segments.

[0112] For illustrative purposes, a time-varying motion signal represented by a time-varying motion waveform is used as an example. The processing device 140 (e.g., the physiological motion segmentation module 420) may divide the time-varying motion waveform into multiple segments. In some embodiments, the processing device 140 may divide the time-varying motion waveform based on instructions from an operator (e.g., a technician, a doctor). For example, based on the operator's instructions, the processing device 140 may evenly divide the time-varying motion waveform into multiple segments, such that the time bins corresponding to each segment have the same time span. For another example, based on the operator's instructions, the processing device 140 may unevenly divide the time-varying motion waveform into segments, such that at least two segments may have different time spans. In some embodiments, the processing device 140 may use a segmentation model to divide the time-varying motion waveform into at least two segments. By way of example only, the segmentation model may perform segmentation based on the distribution of the waveform. For example, segments with sharply varying portions of the waveform may be assigned a smaller time span, while segments with slowly varying portions of the waveform may be assigned a larger time span. In some embodiments, one or more time-varying motion signal samples having at least two labeled segments may be input into the segmentation model to train the initial segmentation model. When certain conditions are met (eg, a preset iteration count of the training process is met), the trained initial segmentation model can be used as the segmentation model as described above.

[0113] It should be noted that the description of process 700 provided above is for illustrative purposes and is not intended to limit the scope of the present application. For those of ordinary skill in the art, various modifications and changes can be made to the application form and details of the above-mentioned method and system without departing from the principles of the present application. In some embodiments, other technologies can be used without using sensors to obtain time-varying motion signals. For example, by scanning the object in at least one complete cycle of the object's physiological motion, a time-varying motion signal can be derived from one or more images (e.g., movie images) of the object. Based on the motion state of the object in one or more images, for example, the processing device 140 (e.g., the physiological motion segmentation module 420) can directly extract the time-varying motion signal from one or more images. In some embodiments, process 700 may include one or more other operations. However, those changes and modifications also fall within the scope of the present application.

[0114] Figure 8 FIG. 8 is a flow chart of an exemplary process 800 for determining at least two axial positions of a radiation source according to some embodiments of the present application. In some embodiments, at least a portion of the process 800 may be performed by the processing device 140 (e.g., Figure 2 For example, process 800 may be stored in a storage device (e.g., storage device 150, memory 220, memory 390) in the form of instructions (e.g., an application program) and executed by processing device 140 (e.g., Figure 2 The processor 210 shown, Figure 3 The CPU 340 or Figure 4 The operations of the process shown below are for illustration purposes only. In some embodiments, process 800 may be accomplished using one or more additional operations not described and / or one or more operations not discussed. Figure 8 The order in which the operations of process 800 are shown and described below is not intended to be limiting. In some embodiments, operation 506 may be implemented according to process 800.

[0115] At 802 , the processing device 140 (eg, the axial position determination module 430 ) may determine the axial coverage of a radiation beam emitted from a radiation source.

[0116] The axial coverage of the radiation beam may refer to the spatial extent of the radiation beam along an axis that extends axially and passes through the isocenter of the imaging device 110. In some embodiments, the axial coverage of the radiation beam may also be referred to as the axial field of view of the radiation beam.

[0117] In 804, the processing device 140 (e.g., the axial position determination module 430) can determine at least two axial positions of the radiation source such that the axial motion range of the region of interest is within a combination of the axial coverage ranges of the radiation source at the at least two axial positions relative to the object.

[0118] In some embodiments, the processing device 140 (e.g., the axial position determination module 430) may determine at least two axial positions of the radiation source based on the axial range of motion of the region of interest and the axial coverage of the radiation beam emitted from the radiation source. For example, the processing device 140 (e.g., the axial position determination module 430) may determine at least two simulated axial positions and determine a simulated combination of the axial coverage of the radiation beam emitted by the radiation source at the at least two simulated axial positions relative to the object. The processing device 140 (e.g., the axial position determination module 430) may then compare the simulated combination of the axial coverage with the axial range of motion of the region of interest. Furthermore, based on the comparison result, the processing device 140 (e.g., the axial position determination module 430) may adjust the at least two simulated axial positions to determine the at least two axial positions of the radiation source.

[0119] In some embodiments, the at least two axial positions of the radiation source relative to the subject can be varied stepwise or continuously. For example, as the radiation source emits a radiation beam within each time bin, the at least two axial positions relative to the subject can be varied continuously. In another example, the at least two axial positions relative to the subject can be discrete positions, and the radiation source can only emit the radiation beam when the radiation source reaches the designated position.

[0120] It should be noted that the description of process 800 provided above is for illustrative purposes and is not intended to limit the scope of the present application. For those of ordinary skill in the art, various modifications and changes can be made to the application form and details of the above-mentioned method and system without departing from the principles of the present application. For example, the range of motion of the region of interest in the axial direction can be replaced by the real-time axial range of the region of interest in the axial direction. With physiological movement, the real-time axial range of the region of interest can change over time. The processing device 140 (e.g., the axial position determination module 430) can track the movement of the region of interest in real time and determine at least two axial positions relative to the object based on the real-time axial range of the region of interest. That is, the combination of the axial coverage of the radiation source at at least two axial positions relative to the object can change over time. In some embodiments, one or more operations described in process 800 can be omitted.

[0121] Figure 9is a flow chart of an exemplary process 900 for causing a radiation source to emit a radiation beam according to some embodiments of the present application. In some embodiments, at least a portion of the process 900 may be performed by the processing device 140 (e.g., Figure 2 For example, process 900 may be stored in a storage device (e.g., storage device 150, memory 220, memory 390) in the form of instructions (e.g., an application program) and executed by processing device 140 (e.g., Figure 2 The processor 210 shown, Figure 3 The CPU 340 or Figure 4 The operations of the process shown below are for illustration purposes only. In some embodiments, process 900 may be accomplished using one or more additional operations not described and / or one or more operations not discussed. Figure 9 The order in which the operations of process 900 are shown and described below is not intended to be limiting. In some embodiments, operation 508 may be implemented according to process 900.

[0122] In some embodiments, the object may be supported by a table that is movable in the axial direction (e.g., the table 114 of the imaging device 110). For example, in any of CT imaging systems, PET-CT imaging systems, and CT linear accelerator systems, the table supporting the object may be movable in the axial direction.

[0123] In 902 , the processing device 140 (eg, the radiation beam emission module 440 ) may move a table to a table position such that a radiation source is located at one of at least two axial positions relative to an object.

[0124] In some embodiments, at least two axial positions may be represented using one or more sets of coordinates. For example, the processing device 140 (e.g., the axial position determination module 430) may establish a coordinate system whose origin is, for example, at the isocenter of the imaging device 110, the location of the radiation source (or the location of the gantry 113 of the imaging device 110). And, based on the at least two axial positions represented using one or more sets of coordinates, the processing device 140 (e.g., the radiation beam emission module 440) may move the table to a table position. In some embodiments, within each time bin as described herein, the processing device 140 may move the table to different table positions such that the radiation beam may fully cover the range of motion (or real-time axial range) of the region of interest in the time bin.

[0125] In 904 , when the table is in the table position, the processing device 140 (eg, the radiation beam emission module 440 ) may cause the radiation source to emit a radiation beam toward the region of interest.

[0126] In some embodiments, the radiation source can generate X-rays with at least two different energy spectra. In a dual-energy CT system with a single radiation source (e.g., scanning source 115), the X-ray tube included in the single radiation source can generate X-rays using a power supply provided by a voltage generator. The power supply provided by the voltage generator can quickly switch between a low X-ray tube voltage and a high X-ray tube voltage, and then generate X-rays with two different energy spectra to scan the region of interest. Alternatively, or in addition, the single radiation source can have two or more focal spots on the anode, so that the single radiation source can emit radiation beams at different viewing angles. Alternatively, the single radiation source can be replaced by multiple radiation sources. Each of the multiple radiation sources can emit X-rays with the same or different energy spectra at different viewing angles. Alternatively, a multi-layer detector can be used to achieve additional energy spectrum-based contrast, where each detector layer exhibits a different energy response.

[0127] It should be noted that the description of the process 900 provided above is for illustrative purposes, rather than intended to limit the scope of the application. For those of ordinary skill in the art, without departing from the principles of the application, various modifications and changes can be made to the application form and details of the above-mentioned method and system. In certain embodiments, the process 900 may include one or more other operations. However, those variations and modifications also fall within the scope of the application.

[0128] Figure 10 is a flow chart of an exemplary process 1000 for causing a radiation source to emit a radiation beam according to some embodiments of the present application. In some embodiments, at least a portion of the process 1000 may be performed by the processing device 140 (e.g., Figure 2 For example, process 1000 may be stored in a storage device (e.g., storage device 150, memory 220, memory 390) in the form of instructions (e.g., an application program) and executed by processing device 140 (e.g., Figure 2 The processor 210 shown, Figure 3 The CPU 340 or Figure 4 The operations of the process shown below are for illustration purposes only. In some embodiments, process 1000 may be accomplished using one or more additional operations not described and / or one or more operations not discussed. Figure 10 The order in which the operations of process 1000 are shown and described below is not intended to be limiting. In some embodiments, operation 508 may be implemented according to process 1000.

[0129] In some embodiments, the radiation source may be mounted on a gantry that is movable in the axial direction (eg, the gantry 113 of the imaging device 110). For example, in a rail-mounted CT system, the gantry may be movable in the axial direction.

[0130] In 1002 , the processing device 140 (eg, the radiation beam emission module 440 ) may move a gantry to a gantry position such that a radiation source is located at one of at least two axial positions relative to a subject.

[0131] In some embodiments, at least two axial positions can be represented using one or more sets of coordinates. For example, the processing device 140 (e.g., the axial position determination module 430) can establish a coordinate system whose origin is, for example, at the isocenter of the imaging device 110, a position on the table (e.g., a position on the table 114 of the imaging device 110). And, based on the at least two axial positions represented using one or more sets of coordinates, the processing device 140 (e.g., the radiation beam emission module 440) can move the gantry to a gantry position. In some embodiments, within each time bin as described herein, the processing device 140 can move the gantry to different gantry positions so that the radiation beam can fully cover the motion range (or real-time axial range) of the region of interest in the time bin.

[0132] In 1004, when the gantry is in the gantry position, the processing device 140 (e.g., the radiation beam emission module 440) may cause the radiation source to emit a radiation beam to the region of interest. Further description of emitting a radiation beam may be found elsewhere in this application. See, e.g., Figure 9 and its description.

[0133] It should be noted that the description of process 1000 provided above is for illustrative purposes, rather than intended to limit the scope of the application. For those of ordinary skill in the art, various modifications and changes can be made to the application form and details of the above-mentioned method and system without departing from the principles of the application. In some embodiments, process 1000 may include one or more other operations. However, those variations and modifications also fall within the scope of the application.

[0134] Figure 11 FIG. 1 is a flow chart of an exemplary process 1100 for determining at least one time bin according to some embodiments of the present application. In some embodiments, at least a portion of the process 1100 may be performed by the processing device 140 (e.g., Figure 2 For example, process 1100 may be stored in a storage device (e.g., storage device 150, memory 220, memory 390) in the form of instructions (e.g., an application program) and executed by processing device 140 (e.g., Figure 2The processor 210 shown, Figure 3 The CPU 340 or Figure 4 The operations of the process shown below are for illustration purposes only. In some embodiments, process 1100 may be accomplished using one or more additional operations not described and / or one or more operations not discussed. Figure 11 The order in which the operations of process 1100 are shown and described below is not intended to be limiting. In some embodiments, operation 512 may be implemented according to process 1100.

[0135] In 1102 , the processing device 140 (eg, the time bin determination module 460 ) may obtain a planned location of a region of interest at which a treatment beam is to be transmitted.

[0136] In some embodiments, the planned position of the region of interest at which the treatment beam is to be emitted can be set in a predetermined treatment plan. For example, based on a previous CT scan, the operator can determine the planned position of the region of interest at which the treatment beam is to be emitted. In some embodiments, the planned position of the region of interest can include the position of the region of interest relative to other organs / tissues in the subject, the position of the region of interest relative to the radiation source emitting the treatment beam, the position of the region of interest relative to other components of the imaging device 110 (e.g., the gantry 113), etc., or a combination thereof. Information related to the planned position (e.g., a set of one or more coordinates) can be stored in a storage device (e.g., the storage device 150, the memory 220, the memory 390). The processing device 140 (e.g., the time bin determination module 460) can obtain the planned position of the region of interest from the storage device and emit the treatment beam at the planned position.

[0137] In 1104, the processing device 140 (eg, the time bin determination module 460) may determine a position of at least one region of interest among the axial positions of the regions of interest that matches a planned position of the region of interest at which the treatment beam is to be emitted.

[0138] In some embodiments, the axial position of the region of interest may be determined as described elsewhere herein (e.g., operation 510). For example, the processing device 140 may determine the axial position of the region of interest by identifying the region of interest in image frames generated by an "exhaustive scan" or a "predictive scan" in each time bin.

[0139] In some embodiments, a match between the axial position of the region of interest and the planned position of the region of interest may indicate that the axial position of the region of interest relative to another organ / tissue in the subject may be the same as the planned axial position of the region of interest relative to the same organ / tissue in the subject. In some embodiments, the processing device 140 (e.g., the time bin determination module 460) may acquire an image of the region of interest at the planned position (e.g., the planning image) and compare it with image frames corresponding to different time bins and different axial positions of the region of interest. If the image of the region of interest at the planned position is consistent with a particular image frame (e.g., the positions of the region of interest in the two images are consistent with each other), the processing device 140 (e.g., the time bin determination module 460) may determine that the position of the region of interest in the particular image frame is one of the at least one positions of the region of interest that matches the planned position of the region of interest at which the treatment beam is to be emitted.

[0140] In 1106 , based on the at least one matching location of the region of interest, the processing device 140 (eg, the time bin determination module 460 ) may determine at least one time bin.

[0141] As described elsewhere in this application, for each of at least two time bins in the entire cycle of physiological motion, the axial position of the region of interest can be determined. In addition, a relationship between the axial position of the region of interest and the physiological motion (e.g., represented by a time-varying motion signal) can be established. Based on the relationship, the processing device 140 can determine at least one time bin corresponding to at least one matching position of the region of interest.

[0142] In some embodiments, after determining the at least one time bin, the processing device 140 may cause the imaging device 110 (e.g., the table 114) to move the subject to a treatment position, and may transmit a treatment beam to the planned position of the region of interest within a time interval corresponding to the at least one time bin. A time interval may be considered to correspond to the at least one time bin if the time interval and the at least one time bin correspond to the same phase of physiological motion (e.g., respiratory motion, cardiac motion).

[0143] It should be noted that the description of process 1100 provided above is for illustrative purposes and is not intended to limit the scope of the present application. For those of ordinary skill in the art, various modifications and changes can be made to the application form and details of the above-mentioned method and system without departing from the principles of the present application. In some embodiments, process 1100 may include one or more other operations. However, those changes and modifications also fall within the scope of the present application. For example, the operations shown in process 1100 can be applied to other applications, including, for example, surgical intervention and treatments such as high-intensity focused ultrasound (HIFU), hyperthermia, brachytherapy, cryotherapy, etc., or any combination thereof.

[0144] Within the scope of the above description of therapeutic applications to beams originating from outside the patient, it will be appreciated that the therapeutic beam can enter the patient from one or more angles, or from one or more continuous ranges of angles. Furthermore, it will be appreciated that by imaging the region of interest from the angle at which the external therapeutic beam will enter the patient, the trajectory of the region of interest having an axial component of motion can be most relevantly determined from the field of view (beam direction view) corresponding to the beam angle / range of beam angles at which the therapeutic beam is intended to enter the patient. Such therapeutic beams may include X-ray beams, charged particle beams, neutron beams, ultrasound beams, and the like.

[0145] The basic concepts have been described above. It will be apparent to those skilled in the art after reading this application that the above disclosures are merely illustrative and do not constitute limitations on this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to this application. Such modifications, improvements, and amendments are suggested in this application and remain within the spirit and scope of the exemplary embodiments of this application.

[0146] At the same time, this application uses specific terms to describe the embodiments of the 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 application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application may be appropriately combined.

[0147] In addition, it will be appreciated by those skilled in the art that the various aspects of the present application can be illustrated and described by a number of patentable categories or situations, including any new and useful combination of processes, machines, products or substances, or any new and useful improvements thereto. Correspondingly, the various aspects of the present application can 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 be referred to as a "unit," "component," or "system." In addition, the various aspects of the present application can take the form of a computer program product embodied in one or more computer-readable media, wherein the computer-readable program code is contained therein.

[0148] A computer-readable signal medium may include a propagated data signal embodying computer program code, for example, in baseband or as part of a carrier wave. Such propagated signals may take a variety of forms, including electromagnetic, optical, or any suitable combination. A computer-readable signal medium may be any computer-readable medium other than a computer-readable storage medium that can be connected to an instruction execution system, apparatus, or device to communicate, propagate, or transfer a program for use. Program code on a computer-readable signal medium may be propagated via any suitable medium, including radio, cable, fiber optic cable, RF, or any combination of the foregoing.

[0149] The computer program code required for the operation of each part of the present application can be written in any one or more programming languages, including object-oriented programming languages ​​such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.NET, Python, etc., conventional procedural programming languages ​​such as C programming language, Visual Basic, Fortran2003, Perl, COBOL 2002, PHP, ABAP, dynamic programming languages ​​such as Python, Ruby and Groovy, or other programming languages. The program code can be run entirely on the user's computer, or as an independent software package on the user's computer, or partly on the user's computer and partly on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer through any network form, such as a local area network (LAN) or a wide area network (WAN), or connected to an external computer (e.g., via the Internet), or in a cloud computing environment, or used as a service such as software as a service (SaaS).

[0150] In addition, unless expressly 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 of the invention embodiments 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 system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0151] Similarly, it should be noted that, in order to simplify the presentation of this disclosure and thereby facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this disclosure sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this approach should not be interpreted as reflecting an intention that the claimed object material to be scanned requires more features than those expressly recited in each claim. In practice, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0152] In some embodiments, the numbers representing quantities or properties used to describe and claim certain embodiments of the present application should be understood to be modified by the terms "about", "approximately" or "substantially" in some cases. For example, unless otherwise stated, "about", "approximately" or "substantially" can indicate a ±20% variation of the value it describes. 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, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical fields and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0153] 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 limit 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, definitions, and / or use of terms associated with any incorporated material and the terminology associated with this document, the description, definitions, and / or use of terminology in this document will control.

[0154] Finally, it should be understood that the embodiments described in this application are merely illustrative of the principles of the embodiments of this application. Other variations may also fall within the scope of this application. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this application may be considered consistent with the teachings of this application. Accordingly, the embodiments of this application are not limited to the embodiments explicitly introduced and described in this application.

Claims

1. A system comprising: at least one storage medium comprising a set of instructions; as well as at least one processor in communication with the at least one storage medium, wherein, when executing the instructions, the at least one processor is configured to cause the system to perform operations comprising: Determine the axial extent of a region of interest of the subject; Determining at least two axial positions of a radiation source relative to the object comprises: determining the axial coverage of the radiation beam of the radiation source; determining the at least two axial positions of the radiation source so that the extent of the region of interest in the axial direction is within a combination of the axial coverage of the radiation source at the at least two axial positions relative to the object; and tracking the motion of the region of interest; determining the at least two axial positions relative to the object based on the tracked motion of the region of interest; causing the radiation source to emit the radiation beam toward the region of interest at each of the at least two axial positions relative to the object to generate an image frame of the region of interest, wherein the radiation beams corresponding to the at least two axial positions together cover the range of the region of interest in the axial direction; and Based on the image frames of the region of interest, positions of the region of interest in the axial direction are determined, at least one of the positions matching a planned position of the region of interest at which a treatment beam is to be emitted.

2. The system according to claim 1, wherein: The determining of the axial range of the region of interest of the object includes: acquiring an image of the object based on the scan of the object; identifying the region of interest in the image of the object; and Based on the identified region of interest, the extent of the region of interest is determined.

3. The system according to claim 1, wherein: The radiation source generates X-rays having at least two different energy spectra.

4. The system according to claim 1, wherein: The object is supported by a table movable in the axial direction, wherein causing the radiation source to emit the radiation beam toward the region of interest at each of the at least two axial positions relative to the object to generate an image frame of the region of interest comprises: moving the table to a table position such that the radiation source is located at one of the at least two axial positions relative to the object; and When the table is at the table position, the radiation source is caused to emit the radiation beam toward the region of interest.

5. The system according to claim 1, wherein: The radiation source is mounted on a gantry movable along the axial direction, wherein causing the radiation source to emit the radiation beam toward the region of interest at each of the at least two axial positions relative to the object to generate an image frame of the region of interest comprises: moving the gantry to a gantry position such that the radiation source is located at one of the at least two axial positions relative to the subject; and When the gantry is in the gantry position, the radiation source is caused to emit the radiation beam toward the region of interest.

6. The system according to claim 1, wherein: The causing the radiation source to emit the radiation beam toward the region of interest at each of the at least two axial positions relative to the object to generate an image frame of the region of interest comprises: The radiation source is caused to emit the radiation beam toward the region of interest at each of the at least two axial positions relative to the subject from one or more angles at which the treatment beam is to be emitted toward the region of interest.

7. A method for imaging a moving object, comprising: Determine the axial extent of a region of interest of the subject; Determining at least two axial positions of a radiation source relative to the object comprises: determining the axial coverage of the radiation beam of the radiation source; determining the at least two axial positions of the radiation source so that the extent of the region of interest in the axial direction is within a combination of the axial coverage of the radiation source at the at least two axial positions relative to the object; and tracking the motion of the region of interest; determining the at least two axial positions relative to the object based on the tracked motion of the region of interest; causing the radiation source to emit the radiation beam toward the region of interest at each of the at least two axial positions relative to the object to generate an image frame of the region of interest, wherein the radiation beams corresponding to the at least two axial positions together cover the range of the region of interest in the axial direction; and Based on the image frames of the region of interest, positions of the region of interest in the axial direction are determined, at least one of the positions matching a planned position of the region of interest at which a treatment beam is to be emitted.

8. The method according to claim 7, characterized in that The determining of the axial range of the region of interest of the object includes: acquiring an image of the object based on the scan of the object; identifying the region of interest in the image of the object; and Based on the identified region of interest, the extent of the region of interest is determined.

9. The method according to claim 7, characterized in that The causing the radiation source to emit the radiation beam toward the region of interest at each of the at least two axial positions relative to the object to generate an image frame of the region of interest comprises: The radiation source is caused to emit the radiation beam toward the region of interest at each of the at least two axial positions relative to the subject from one or more angles at which the treatment beam is to be emitted toward the region of interest.

10. A computer-readable storage medium storing computer instructions, wherein when a computer reads the computer instructions in the storage medium, the computer executes the method according to any one of claims 7 to 9.

Images