Medical imaging system and medical imaging method

Abstract

The application relates to a medical imaging system, a medical imaging method and a computer readable storage medium. The method comprises the following steps: obtaining first projection data by detecting radioactive rays passing through a first scanning field of view, and simultaneously detecting a part of radioactive rays in radioactive rays not passing through the first scanning field of view but passing through a second scanning field of view to obtain second projection data, wherein the second scanning field of view is larger than the first scanning field of view, and the first scanning field of view is located in the second scanning field of view; obtaining third projection data corresponding to the second scanning field of view based on the first projection data and the second projection data; and reconstructing a tomographic image in the second scanning field of view based on the third projection data. Through the application, the problem that the signal in the extended scanning field of view obtained by speculation is greatly different from the real signal in the related art is solved, and the reconstruction quality of the computer tomographic image is improved.

Description

Technical Field

[0001] This application relates to the field of computed tomography, and in particular to medical imaging systems, medical imaging methods, and computer-readable storage media. Background Technology

[0002] Figure 1 This is a schematic diagram of the field of view (FOV) in a computed tomography (CT) scan based on related technologies, such as... Figure 1 As shown, in some special scenarios of CT scanning (such as obese patients or interventional scans), the scanned object may exceed the standard field of view (FOV) of CT. In such cases, CT may require extended FOV reconstruction. However, for extended FOV imaging, some projection angles may have insufficient data (this is determined by the CT system geometry design, which only ensures sufficient data for standard FOV reconstruction). Direct reconstruction will result in severe image artifacts.

[0003] In such cases, the extended FOV method is typically used for reconstruction. This involves inferring data outside the FOV based on existing data and then using this data to reconstruct an image with an extended FOV. However, current extended FOV methods infer data outside the FOV from data within the FOV without any other reference information, leading to a significant discrepancy between the inferred signal and the actual signal. Summary of the Invention

[0004] This embodiment provides a medical imaging system, a medical imaging method, and a computer-readable storage medium to address the problem in related technologies where the predicted signal within the extended scanning field of view differs significantly from the actual signal.

[0005] In a first aspect, this embodiment provides a medical imaging system including a scanning component and a processing device. The scanning component includes a radiation source and a first detector, wherein the radiation source is used to generate radioactive rays, and the first detector is used to detect radioactive rays passing through a first scanning field of view.

[0006] The scanning assembly further includes at least one set of second detectors, which are used to detect a portion of the radioactive rays that do not pass through the first scanning field of view but pass through the second scanning field of view, wherein the second scanning field of view is larger than the first scanning field of view, and the first scanning field of view is located within the second scanning field of view;

[0007] The processing device is used to acquire third projection data corresponding to the second scanning field of view based on first projection data and second projection data, and to reconstruct a tomographic image within the second scanning field of view based on the third projection data, wherein the first projection data is detected by the first detector and the second projection data is detected by the second detector.

[0008] In some embodiments, the second detectors are in multiple groups, and the detectors in each group are disposed on an extension line of the first detectors and are spaced apart from the adjacent first detectors or other second detectors.

[0009] In some embodiments, the second detectors include multiple detector units, and the detector units are symmetrically disposed on an extension line of the first detectors and are spaced apart from the first detectors.

[0010] In some embodiments, the processing device includes a fitting unit, a combining unit and a reconstruction unit, wherein,

[0011] The fitting unit is configured to fit the first projection data and the second projection data to obtain fourth projection data corresponding to a residual scanning field of view, wherein the residual scanning field of view is located outside the first scanning field of view but inside the second scanning field of view.

[0012] The combining unit is configured to combine the first projection data and the fourth projection data to obtain the third projection data.

[0013] The reconstruction unit is configured to reconstruct a tomographic image inside the second scanning field of view based on the third projection data.

[0014] In some embodiments, the fitting unit includes:

[0015] An extrapolation subunit is configured to extrapolate based on the first projection data to obtain fifth projection data.

[0016] A weight curve fitting subunit is configured to fit a weight curve based on a ratio of the second projection data to projection data in the fifth projection data corresponding to a position of the second detector as a constraint condition.

[0017] A data generation subunit is configured to perform weighted calculation on the second projection data based on the weight curve to obtain the fourth projection data.

[0018] In a second aspect, a medical imaging method is provided in the embodiments, including:

[0019] Detecting radioactive rays passing through a first scanning field of view to obtain first projection data, and detecting a part of radioactive rays not passing through the first scanning field of view but passing through a second scanning field of view to obtain second projection data, wherein the second scanning field of view is larger than the first scanning field of view, and the first scanning field of view is located inside the second scanning field of view.

[0020] acquire third projection data corresponding to the second scan field of view based on the first projection data and the second projection data;

[0021] reconstruct a tomographic image within the second scan field of view based on the third projection data.

[0022] In some embodiments, the first projection data is detected by a first detector, and the second projection data is detected by a second detector, the second detector is a plurality of groups, and each group of the second detector is arranged apart from the adjacent first detector or other second detector.

[0023] In some embodiments, acquiring third projection data based on the first projection data and the second projection data comprises:

[0024] fitting fourth projection data corresponding to a residual scan field of view based on the first projection data and the second projection data, wherein the residual scan field of view is located outside the first scan field of view but within the second scan field of view;

[0025] combining the first projection data and the fourth projection data to obtain the third projection data.

[0026] In some embodiments, fitting fourth projection data corresponding to a residual scan field of view based on the first projection data and the second projection data comprises:

[0027] extrapolating fifth projection data based on the first projection data;

[0028] fitting a weight curve based on a ratio of projection data corresponding to the position of the second detector in the second projection data and the fifth projection data as a constraint condition;

[0029] weighting and calculating the second projection data based on the weight curve to obtain the fourth projection data.

[0030] In a third aspect, a computer readable storage medium is provided in the present embodiment, and the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the medical imaging method in the second aspect.

[0031] Compared with the related art, the medical imaging system, the medical imaging method and the computer readable storage medium provided in the embodiment obtain first projection data by detecting radioactive rays passing through a first scanning field of view, and obtain second projection data by detecting a part of radioactive rays not passing through the first scanning field of view but passing through a second scanning field of view, wherein the second scanning field of view is larger than the first scanning field of view, and the first scanning field of view is located in the second scanning field of view; third projection data corresponding to the second scanning field of view is acquired based on the first projection data and the second projection data; and a tomographic image in the second scanning field of view is reconstructed based on the third projection data, so that the problem that a signal in an extended scanning field of view obtained by speculation in the related art is greatly different from a real signal is solved, and the reconstruction quality of a computer tomographic image is improved.

[0032] The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the application will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF DRAWINGS

[0033] These and other features, aspects, and advantages of the present application can become better understood with reference to the following description and accompanying drawings, wherein:

[0034] In the drawings:

[0035] Figure 1 is a schematic diagram of a scanning field of view (FOV) of a computed tomography (CT) scan according to the related art.

[0036] Figure 2 is a schematic diagram of a medical imaging system according to an embodiment of the application.

[0037] Figure 3 is a schematic diagram of exemplary hardware and / or software components of a computer device 200 according to some embodiments of the application.

[0038] Figure 4 is a schematic diagram of a scanning assembly of a medical imaging system according to an embodiment of the application.

[0039] Figure 5 is a schematic diagram of a scanning assembly of a medical imaging system according to an embodiment of the application.

[0040] Figure 6 is a schematic diagram of a scanning assembly of a medical imaging system according to a preferred embodiment of the application.

[0041] Figure 7 is a structural block diagram of a medical scanning system according to a preferred embodiment of the present application.

[0042] Figure 8 is a schematic diagram of extrapolating projection data of a residual FOV based on projection data of a standard FOV according to an embodiment of the present application.

[0043] Figure 9 is a flowchart of a medical imaging method according to an embodiment of the present application.

[0044] Figure 10 is a schematic diagram of a generation process of fourth projection data according to a preferred embodiment of the present application.

[0045] Figure 11 is a flowchart of a generation process of fourth projection data according to a preferred embodiment of the present application. DETAILED DESCRIPTION

[0046] For more clearly understanding of the purpose, technical scheme and advantages of the present application, the present application is described and explained in the following with reference to the drawings and embodiments. However, it should be understood by those skilled in the art that the present application can be implemented without these details. In some cases, in order to avoid unnecessary description to make aspects of the present application obscure, well-known methods, processes, systems, components and / or circuits which have been described at a higher level will not be described in more detail. It is obvious for those skilled in the art that various changes can be made to the embodiments disclosed in the present application, 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 shown embodiments, but conforms to the broadest scope claimed by the present application.

[0047] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the general meaning understood by those skilled in the art to which the present application belongs. The terms used in the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. As used in the present application, "one", "a", "an", "the", "these", and similar words do not represent quantitative limitation, but can be singular or plural. In the present application, the terms "include", "contain", "have" and any variants thereof are intended to cover non-exclusive inclusion; for example, a process, method and system, product or device containing a series of steps or modules (units) are not limited to the listed steps or modules (units), but can include steps or modules (units) not listed, or can include other steps or modules (units) inherent to the process, method, product or device.

[0048] The term "plurality" as used herein means two or more. Generally, the character " / " means that the objects before and after it are in an "or" relationship. The terms "first", "second", "third", etc. as used herein are only used to distinguish similar objects, and do not represent a specific order for the objects.

[0049] The terms "system", "engine", "unit", "module" and / or "block" as used herein are a method for distinguishing different components, elements, parts, members, assemblies, or functions at different levels. These terms can be replaced by other expressions capable of achieving the same purpose. Generally, the "module", "unit" or "block" referred to in the present application refers to a set of logic or software instructions embodied in hardware or firmware. The "module", "unit" or "block" described in the present application can be implemented as software and / or hardware, and in the case of software implementation, they can be stored in any type of non-volatile computer readable storage medium or storage device.

[0050] In some embodiments, software modules / units / blocks can be compiled and linked into executable programs. It will be appreciated that software modules can be callable from other modules / units / blocks or from themselves, and / or can be invoked in response to detected events or interrupts. Software modules / units / blocks configured for execution on the computing device can be stored in computer-readable storage media such as optical, digital, video or any other tangible media, or as a digital download (and can initially be stored in a compressed or installable format that requires installation, decompression or decryption before execution). Such software code can be stored partially or entirely in the memory device of the computing device executing the code, and applied in the operation of the computing device. Software instructions can be embedded in firmware, such as EPROM. It will also be appreciated that hardware modules / units / blocks can be included in connected logic components, such as gates and flip-flops, and / or can be included in programmable logic components, 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. Generally, the modules / units / blocks described herein, which can be combined with other modules / units / blocks, or although they are physically organized or stored, can be divided into sub-modules / sub-units / sub-blocks. The description can be applicable to the system, engine or part thereof.

[0051] It will be understood that where a unit, engine, module, or block is referred to above as being "on", "connected to", or "coupled to" another unit, engine, module, or block, that other unit, engine, module, or block can be directly on, connected to, or coupled to the unit, engine, module, or block, or there can be intervening units, engines, modules, or blocks between the two, unless the context clearly indicates otherwise. In this application, the term "and / or" can include any one or more of the associated listed items, or combination thereof.

[0052] The term "image" in this application is used to collectively refer to image data (e.g., scan data, projection data) and / or various forms of images, including two-dimensional (2D) images, three-dimensional (3D) images, etc. The terms "pixel" and "voxel" in this application are used interchangeably to refer to an element of an image. In this application, the terms "region", "location", and "zone" can refer to a location of an anatomical structure shown in an image, or to an actual location of an anatomical structure present in or on a target subject. Thus, an image can indicate an actual location of certain anatomical structures present in or on a target subject.

[0053] In this embodiment, a subject is a target subject to be scanned, simply referred to as a target subject. The part in this embodiment refers to a part of a human body that is usually scanned as a whole in medical imaging, such as a head, a heart, an abdomen, a limb, etc.

[0054] This embodiment provides a medical imaging system implemented on a computer device. According to the medical imaging system provided in this embodiment, a computed tomography scanning process can be performed automatically or semi-automatically, and in particular, an extrapolated signal closer to a true signal can be obtained based on a signal and reference information obtained by a traditional scanning field of view (FOV) scanning, so as to improve the signal quality of an extended scanning field of view (FOV), reduce or eliminate artifacts of a scanning image reconstructed by a medical imaging system, and improve imaging quality.

[0055] Figure 2 is a schematic diagram of a medical imaging system according to an embodiment of the present application. As shown in Figure 2 The medical imaging system 100 can include a medical imaging apparatus 110 and a processing device 120. In some embodiments, a storage device 130, and one or more terminals 140 and / or a network 150 can also be included.

[0056] In some embodiments, the medical imaging apparatus 110, the processing device 120, the storage device 130, and / or the terminal 140 can be connected to each other and / or communicate through wireless connection, wired connection, or a combination thereof. For example, the medical imaging apparatus 110 can be connected to the processing device 120 through the network 150 or directly. For another example, the storage device 130 can be connected to the processing device 120 through the network 150 or directly.

[0057] The medical imaging apparatus 110 can generate or provide image data related to a target object by scanning the target object. The medical imaging apparatus 110 can include a single modality scanner and / or a multi-modality scanner. The single modality scanner can include, for example, a computed tomography (CT) scanner. The multi-modality scanner can include, for example, a single photon emission computed tomography-magnetic resonance imaging (SPECT-MRI) scanner, a positron emission tomography-computed tomography (PET-CT) scanner, etc.

[0058] In some embodiments, the medical imaging apparatus 110 can include a gantry 111 formed with a detection region 113, a scanning assembly, and a scanning bed 114. The scanning assembly can include a first detector 112, a radiation source 115, and a second detector 160. The gantry 111 can support the detector 112, the second detector 160, and the radiation source 115. The target object can be placed on the scanning bed 114 and then moved into the detection region 113 for scanning. In some embodiments, the scanning bed 114 can be configured to rotate and / or translate in different directions to move the target object to a desired position. For example, the scanning bed 114 can be configured to rotate and / or translate along or around one or more of the X-axis, the Y-axis, and the Z-axis of the coordinate system 170 shown. The radiation source 115 can emit radioactive rays to the target object. The radioactive rays can include particle rays, photon rays, etc., or a combination thereof. In some embodiments, the radioactive rays can include at least two radioactive particles (e.g., neutrons, protons, electrons, muons, heavy ions), at least two radioactive photons (e.g., X-rays, gamma rays, ultraviolet rays, laser light), etc., or a combination thereof. Figure 2 The radiation source 115 can emit radioactive rays to the target object. The radioactive rays can include particle rays, photon rays, etc., or a combination thereof. In some embodiments, the radioactive rays can include at least two radioactive particles (e.g., neutrons, protons, electrons, muons, heavy ions), at least two radioactive photons (e.g., X-rays, gamma rays, ultraviolet rays, laser light), etc., or a combination thereof.

[0059] The first detector 112 can detect radiation and / or radiation events (e.g., gamma photons) emitted from the detection region 113. In some embodiments, the first detector 112 can include at least two detector units. The detector units can include scintillation detectors (e.g., cesium iodide detectors) or gas detectors. The detector units can be single-row detectors or multi-row detectors. The first detector 112 and the radiation source 115 form a first scanning field of view, which is also referred to as a standard FOV; radioactive rays passing through the standard FOV can be detected by the first detector 112.

[0060] The second detector 160 can also detect radiation and / or radiation events (e.g., gamma photons) emitted from the detection region 113. In some embodiments, the second detector 160 can include at least one detector unit. The detector unit can include a scintillation detector (e.g., cesium iodide detector) or a gas detector. The detector unit can be a single row detector or a multi-row detector. The second detector 160 and the radiation source 115 form a second scan field of view, which is also referred to as an extended FOV; the extended FOV is larger than the standard FOV, and the standard FOV is located within the extended FOV. A portion of the radioactive rays that do not pass through the standard FOV but pass through the extended FOV can be detected by the second detector 160.

[0061] The processing device 120 can process data and / or information acquired from the medical imaging apparatus 110, the storage device 130, and / or the terminal 140, and implement control of the medical imaging apparatus 110, the storage device 130, and / or the terminal 140. For example, the processing device 120 can implement control of the medical imaging system to implement the medical imaging method provided in the present application.

[0062] In some embodiments, the processing device 120 can be a single server or a group of servers. The group of servers can be centralized or distributed. In some embodiments, the processing device 120 can be local or remote to the imaging system 100. In some embodiments, the processing device 120 can be implemented by a computer device 200 having one or more components as described. Figure 2

[0063] In some embodiments, the processing device 120 can include one or more processors (e.g., single-chip processors or multi-chip processors). For example only, the processing device 120 can include a central processing unit (CPU), an application-specific integrated circuit (ASIC), an application-specific instruction-set processor (ASIP), a graphics processing unit (GPU), a physics processing unit (PPU), a digital signal processor (DSP), a field-programmable gate array (FPGA), a programmable logic device (PLD), a controller, a microcontroller unit, a reduced instruction set computer (RISC), a microprocessor, and / or the like, or any combination thereof.

[0064] The storage device 130 can store data, instructions, and / or any other information. In some embodiments, the storage device 130 can store data acquired from the processing device 120, the terminal 140, and / or the medical imaging apparatus 110. In some embodiments, the storage device 130 can store data and / or instructions that can be executed by the processing device 120 to perform the example methods described in the present application.

[0065] ​In some embodiments, the storage device 130 can be connected to the network 150 to communicate with one or more other components of the imaging system 100 (e.g., the processing device 120, the terminal 140). One or more components of the imaging system 100 can access data or instructions stored in the storage device 130 via the network 150. In some embodiments, the storage device 130 can be part of the processing device 120.

[0066] The terminal 140 can enable interaction between a user and the imaging system 100. For example, the terminal 140 can display a target image of a target object with at least two annotations of at least two regions of the target object. For another example, the terminal 140 can display a virtual scan performed using a virtual imaging system. In some embodiments, the terminal 140 can include a mobile device, a tablet computer, a laptop computer, etc., or any combination thereof. For example, the mobile device can include a mobile phone, a personal digital assistant (PDA), a gaming device, a navigation device, a point-of-sale (POS) device, a laptop computer, a tablet computer, a desktop computer, etc., or any combination thereof. In some embodiments, the terminal 140 can include an input device, an output device, etc. In some embodiments, the terminal 140 can be part of the processing device 120.

[0067] The network 150 can include any suitable network that can facilitate the exchange of information and / or data of the imaging system 100. In some embodiments, one or more components of the imaging system 100 (e.g., the medical imaging apparatus 110, the processing device 120, the storage device 130, the terminal 140) can communicate information and / or data with other components of the imaging system 100 via the network 150. For example, the processing device 120 can acquire medical image data from the medical imaging apparatus 110 over the network 150. For another example, the processing device 120 can acquire user instructions from the terminal 140 via the network 150.

[0068] The network 150 can be or include a public network (e.g., the Internet), a private network (e.g., a local area network (LAN)), a wired network, a wireless network (e.g., an 802.11 network, a Wi-Fi network), a frame relay connection, a virtual private network (VPN), a satellite network, a telephone network, routers, hubs, switches, server computers, and / or any combination thereof. For example, the network 150 can include a cable network, a wired network, a fiber-optic network, a telecommunication network, an intranet, a wireless local area network (WLAN), a metropolitan area network (MAN), a public switched telephone network (PSTN), a Bluetooth network, a ZigBee network, a near-field communication (NFC) network, and / or the like, or any combination thereof. In some embodiments, the network 150 can include one or more network access points. For example, the network 150 can include wired and / or wireless network access points, such as base stations and / or Internet exchange points, through which one or more components of the imaging system 100 can connect to the network 150 to exchange data and / or information.

[0069] In some embodiments, a coordinate system can be provided for the imaging system 100 to define positions (e.g., absolute positions, positions relative to another component) of components and / or motions of components. For purposes of illustration, the coordinate system 170 can include an X-axis, a Y-axis, and a Z-axis. Figure 2 The illustrated X-axis and Y-axis can be horizontal, and the Z-axis can be vertical. As shown, a positive X-direction along the X-axis can be from a left side to a right side of the scan bed 114 as viewed from a direction facing a front of the medical imaging device 110, a positive Y-direction along the Y-axis can be a direction in which the scan bed 114 moves outward from the imaging system 100 as viewed from a direction facing the front of the medical imaging device 110, and a positive Z-direction along the Z-axis can be from a lower portion of the gantry 111 (or from a floor on which the imaging system 100 is located) to an upper portion of the gantry 111.

[0070] It should be noted that the above description of the imaging system 100 is intended to be illustrative, and not limiting, of the scope of the present application. Numerous alternatives, modifications, and variations will be apparent to those skilled in the art. Features, structures, methods, and other characteristics of the exemplary embodiments described herein can be combined in various ways to achieve yet further exemplary embodiments. For example, the imaging system 100 can include one or more additional components. Additionally or alternatively, one or more components of the imaging system 100, such as the medical imaging device 110 described above, can be omitted. As another example, two or more components of the imaging system 100 can be integrated into a single component. In some embodiments, the imaging system 100 can further include a therapy device, such as a radiation therapy device.

[0071] Figure 3is a schematic diagram of exemplary hardware and / or software components of a computer device 200 according to some embodiments of the present application. As described herein, the computer device 200 can be used to implement any component of the imaging system 100. For example, the processing device 120 and / or the terminal 140 can be implemented on the computer device 200 by its hardware, software programs, firmware, or a combination thereof, respectively. Although only one such computer device is shown, for convenience, the computer functions related to the imaging system 100 described herein can be implemented in a distributed manner on multiple similar platforms to distribute the processing load. As shown, the computer device 200 can include a processor 210, a storage device 220, an input / output (I / O) 230, and a communication port 240. Figure 3

[0072] The processor 210 can execute computer instructions (e.g., program code) and perform the functions of the processing device 120 according to the techniques described herein. The computer instructions can include, for example, routines, programs, objects, components, data structures, procedures, modules, and functions that perform particular functions described herein. For example, the processor 210 can process image data acquired from the medical imaging apparatus 110, the terminal 140, the storage device 130, and / or any other component of the imaging system 100. In some embodiments, the processor 210 can 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 physics 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), and any circuit or processor capable of executing the functions described herein, or any combination of the above, and the like.

[0073] For illustration only, only one processor is described in the computer device 200. However, it should be noted that the computer device 200 in the present application can also include multiple processors, and thus the operations and / or method steps performed by one processor described in the present application can also be performed by multiple processors jointly or individually. For example, if a processor of the computer device 200 performs operation A and operation B in the present application, it should be understood that operation A and operation B can also be performed by two or more different processors in the computer device 200 jointly or individually (e.g., a first processor performs operation A, a second processor performs operation B, or the first processor and the second processor jointly perform operations A and B).

[0074] ​The storage device 220 can store data / information acquired from the medical imaging apparatus 110, the terminal 140, the storage device 130, and / or any other component of the imaging system 100. In some embodiments, the storage device 220 can include a mass storage device, a removable storage device, a volatile read / write memory, a read-only memory (ROM), etc., or any combination thereof. In some embodiments, the storage device 220 can store one or more programs and / or instructions to perform the example methods described in the present application. For example, the storage device 220 can store a program for the processing device 120 to execute to perform automatic scan preparation for a scan to be performed on a target object. For another example, the storage device 220 can store a program for the processing device 120 to execute during a scan of a target object to perform real-time monitoring and / or adjustment operations.

[0075] The I / O 230 can input and / or output signals, data, information, etc. In some embodiments, the I / O 230 can enable user interaction with the processing device 120. In some embodiments, the I / O 230 can include input devices and output devices. The input devices can include alphabetic and other keys entered through a keyboard, a touch screen (e.g., with tactile input or tactile feedback), voice input, eye tracking input, brain monitoring systems, or any other similar input mechanisms. The input information received through the input devices can be transmitted to another component (e.g., the processing device 120) through, for example, a bus, for further processing. Other types of input devices can include a cursor control device, such as a mouse, a trackball, or cursor direction keys, among others. The output devices can include a display (e.g., a liquid crystal display (LCD), a light-emitting diode (LED)-based display, a flat backplane display, a curved screen, a television device, a cathode ray tube (CRT), a touch screen), a speaker, a printer, etc., or a combination thereof.

[0076] The communication port 240 can be connected to a network (e.g., the network 150) to facilitate data communication. The communication port 240 can establish a connection between the processing device 120 and the medical imaging apparatus 110, the terminal 140, and / or the storage device 130. 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, a cable, an optical cable, a telephone line, etc., or any combination thereof. The wireless connection can include, for example, a Bluetooth connection, a Wi-Fi connection, a WiMax connection, a WLAN connection, a ZigBee connection, a mobile network connection (e.g., 3G, 4G, 5G), etc., or a combination thereof. In some embodiments, the communication port 240 can be and / or include a standardized communication port, such as RS232, RS485, etc. In some embodiments, the communication port 240 can be a specially designed communication port.

[0077] For example, the communication port 240 can be designed according to a Digital Imaging and Communications in Medicine (DICOM) protocol.

[0078] To implement the various modules, units and their functions described in the present application, a computer hardware platform can be used as the hardware platform of one or more components described herein. The computer with user interface components can be used to implement a personal computer (PC) or any other type of workstation or terminal device. If the computer is properly programmed, the computer can also be used as a server.

[0079] Figure 4 is a schematic diagram of a scanning assembly of a medical imaging system according to an embodiment of the present application, Figure 5 is a schematic diagram of a scanning assembly and a processing device of a medical imaging system according to an embodiment of the present application. As Figure 4 and Figure 5 shown, the medical imaging system includes a scanning assembly and a processing device 120 Figure 4 (not shown), the scanning assembly includes a radiation source 115 and a first detector 112, wherein the radiation source 115 is configured to generate radioactive rays, and the first detector 112 is configured to detect the radioactive rays that pass through a first scan field of view 310 (i.e., a standard scan field of view, standard FOV), and the first detector 112 is also referred to as a main detector. The scanning assembly further includes at least one set of second detectors 160, and the second detectors 160 are configured to detect a portion of the radioactive rays that do not pass through the first scan field of view 310 but pass through a second scan field of view 320 (i.e., an extended scan field of view, extended FOV). The second detectors 160 are also referred to as auxiliary detectors. Wherein the second scan field of view 320 is larger than the first scan field of view 310, and the first scan field of view 310 is located within the second scan field of view 320.

[0080] The processing device 120 is electrically connected with the first detector 112 and the second detector 160 respectively, and the processing device 120 is configured to acquire third projection data corresponding to the second scan field of view based on first projection data and second projection data, and reconstruct a tomographic image within the second scan field of view based on the third projection data, wherein the first projection data is detected by the first detector 112, and the second projection data is detected by the second detector 160.

[0081] The processing device 120 can include a data acquisition control module. When data acquisition is performed, information obtained by the second detector 160 is also acquired and stored together with the data acquired by the first detector 112 according to the View.

[0082] The aforementioned medical imaging system employs a second detector 160 to detect a portion of the radioactive rays that pass through the second scanning field of view 320 but not through the first scanning field of view 310. Based on the projection data detected by the second detector 160, the projection data extrapolated from the first projection data is calibrated (or standardized), making the extrapolated projection data closer to the actual scan projection data. The computed tomography (CT) image reconstructed based on this extrapolated projection data, which is closer to the actual scan projection data, reduces artifacts compared to CT images reconstructed based on projection data extrapolated using conventional methods, thereby improving image reconstruction quality.

[0083] On the other hand, the second detector 160 only needs to detect radioactive rays in a region outside the standard scanning field of view. The second detector 160 and the first detector 112 are spatially discrete. Compared with the related art, which increases the standard scanning field of view by directly increasing the number of first detectors 112, the method of using the second detector 160 and the first detector 112 in this embodiment reduces the number of detector units, thereby reducing hardware costs and the weight of the scanning components.

[0084] The aforementioned second detector 160 can be one or more groups. Taking multiple groups of second detectors 160 as an example, to reduce the computational complexity of calibrating extrapolated projection data based on the projection data detected by the second detectors 160, multiple groups of second detectors 160 are all arranged on the extension line of the first detector 112. In the scanning component of a medical imaging system, the extension line of the first detector 112 typically extends along a circle or a straight line, and the first detector 112 and each group of second detectors 160 are arranged along this extension line, with each group of second detectors 160 spaced apart from adjacent first detectors 112 or adjacent second detectors 160. Figure 6 The diagram shows the spatial arrangement of the first detector 112 and multiple sets of second detectors 160 when the extension line of the first detector 112 extends along the circumference.

[0085] Furthermore, in some embodiments, multiple sets of second detectors 160 may be symmetrically arranged on both sides of the first detector 112. For example, the second detector 160 includes multiple detector units, which are symmetrically arranged on the extension line of the first detector and spaced apart from the first detector.

[0086] In some embodiments, the extension of the first detector 112 extends along a circumference centered on the radiation source. In this case, the detector elements of the first detector 112 and the second detector 160 are equally spaced from the radiation source.

[0087] In the above embodiments, placing the second detector 160 on the extension line of the first detector 112, symmetrically arranging multiple sets of second detectors 160 on both sides of the first detector 112, and ensuring that the intervals between each detection unit of the first detector 112 and the second detector 160 and the radiation source are equal, all reduce the computational complexity of calibrating extrapolated projection data based on the projection data detected by the second detector 160. However, it is understood that in other embodiments of this application, it is not limited to satisfying all of the above conditions simultaneously, but rather one or more of the above conditions can be selected.

[0088] Figure 7 This is a structural block diagram of a medical scanning system according to a preferred embodiment of this application, such as... Figure 7 As shown, in some embodiments, the processing device 120 includes a fitting unit 1201, a combining unit 1202, and a reconstruction unit 1203. The fitting unit 1201 is used to fit fourth projection data corresponding to the residual scanning field of view 330 based on first and second projection data, wherein the residual scanning field of view 330 is located outside the first scanning field of view but within the second scanning field of view. The combining unit 1202 is used to combine the first and fourth projection data to obtain third projection data. The reconstruction unit 1203 is used to reconstruct the tomographic image within the second scanning field of view based on the third projection data.

[0089] Figure 8 This is a schematic diagram illustrating the extrapolation of residual FOV projection data based on standard FOV projection data according to an embodiment of this application, as shown below. Figure 8 As shown, the value of the projection data at the edge of the extended FOV is 0, while the projection data at the edge of the standard FOV is obtained based on the detector units located at the edge of the first detector 112. The traditional projection data extrapolation method uses a preset curve fitting method to fit the projection data of the residual FOV based on the projection data at the edge of the extended FOV and the projection data obtained from the detector units located at the edge of the first detector 112, as shown below. Figure 8 As shown in curve 1. In this embodiment, the projection data detected by the second detector 160 is used as a constraint condition, and the same preset curve fitting method is used to obtain curve 2. Curve 2 is closer to the value of the real projection data represented by curve 3 than curve 1.

[0090] In the above embodiments, the preset curve fitting methods include, but are not limited to, least squares fitting or spline curve fitting.

[0091] In the above embodiments, the projection data is directly fitted. In other embodiments, the projection data of the residual FOV can be first extrapolated according to a conventional manner, and then the projection data of the residual FOV is calibrated according to a certain weight curve, so as to obtain fourth projection data closer to the real projection data.

[0092] For example, in some of the embodiments, the fitting unit 1201 includes: an extrapolation subunit configured to extrapolate, based on the first projection data, to obtain fifth projection data. A weight curve fitting subunit configured to fit, based on a ratio of the second projection data to projection data of the fifth projection data corresponding to a position of the second detector as a constraint condition, to obtain a weight curve. A data generation subunit configured to weight, based on the weight curve, the second projection data to obtain fourth projection data.

[0093] The weight curve is fitted based on the projection data detected by the second detector 160. When fitting the weight curve, the weight value of the projection data of the extended FOV edge is 0, the weight value of the projection data of the standard FOV edge is 1, and the weight value of the projection data detected by the second detector 160 can be set as a ratio of the projection data detected by the second detector 160 (i.e., the second projection data) to the projection data of the residual FOV (i.e., the fifth projection data) corresponding to the position of the second detector 160.

[0094] Figure 9 is a flowchart of a medical imaging method according to an embodiment of the present application, as shown in Figure 9 The flowchart includes the following steps:

[0095] In step S901, radioactive rays passing through a first scan field are detected to obtain first projection data, and a part of radioactive rays not passing through the first scan field but passing through a second scan field are detected to obtain second projection data, wherein the second scan field is larger than the first scan field, and the first scan field is located in the second scan field.

[0096] In step S902, third projection data corresponding to the second scan field is obtained based on the first projection data and the second projection data.

[0097] In step S903, a tomographic image in the second scan field is reconstructed based on the third projection data.

[0098] In some of the embodiments, the first projection data is detected by a first detector, and the second projection data is detected by a second detector. The second detector is a plurality of groups, and the plurality of groups of the second detector are arranged on an extension line of the first detector, and each group of the second detector is arranged at intervals with adjacent first detectors or other second detectors.

[0099] In some embodiments, the second detector comprises a plurality of detector units, the plurality of detector units are symmetrically arranged on an extension line of the first detector, and the plurality of detector units are arranged at intervals with the first detector.

[0100] In some embodiments, the obtaining the third projection data based on the first projection data and the second projection data comprises: fitting the first projection data and the second projection data to obtain fourth projection data corresponding to a residual scanning field, wherein the residual scanning field is located outside the first scanning field but inside the second scanning field; and combining the first projection data and the fourth projection data to obtain the third projection data.

[0101] In some embodiments, the fitting the first projection data and the second projection data to obtain the fourth projection data corresponding to the residual scanning field comprises: extrapolating the first projection data to obtain fifth projection data; fitting a weight curve based on a ratio of projection data corresponding to a position of the second detector in the second projection data to the fifth projection data as a constraint condition; and calculating the second projection data based on the weight curve to obtain the fourth projection data.

[0102] Figure 10 is a schematic diagram of a generation process of the fourth projection data according to the preferred embodiments of the present application, Figure 11 is a flowchart of the generation process of the fourth projection data according to the preferred embodiments of the present application. As shown in Figure 10 and Figure 11 the flowchart comprises the following steps:

[0103] Step S1101, detecting radioactive rays passing through a first scanning field to obtain first projection data, as shown by curve D0 in Figure 10 Meanwhile, a part of radioactive rays not passing through the first scanning field but passing through a second scanning field is detected to obtain second projection data, as shown by point F in Figure 10 The second scanning field is larger than the first scanning field, and the first scanning field is located within the second scanning field.

[0104] Step S1102, extrapolating the first projection data to obtain fifth projection data, as shown by curve D1 in Figure 10

[0105] Step S1103, determining a ratio of projection data corresponding to a position of the second detector in the second projection data to the fifth projection data.

[0106] For example, when the position corresponding to the second detector is k, the second projection data obtained by the second detector is RD k ​, the extrapolated projection data corresponding to position k in the fifth projection data is ED k , the ratio R k can be expressed as: R k = RD k / ED k .

[0107] In step S1104, the weight curve is fitted based on R k as a constraint condition. Figure 10 The curve W in the figure represents the weight curve.

[0108] In this step, the projection data corresponding to the standard FOV edge has a weight value W(0) = 1, the projection data corresponding to the extended FOV edge has a weight value W(N) = 0, and the projection data detected by the second detector at position k has a weight value W(k) = R k The fitting method of the weight curve can include but is not limited to least square method, spline curve, etc.

[0109] In step S1105, the second projection data is weighted based on the weight curve to obtain fourth projection data. For example, the fourth projection data D3 = D1 x W.

[0110] In step S1106, the first projection data and the fourth projection data are combined to obtain third projection data, which is the projection data of the entire extended FOV.

[0111] In step S1107, the tomographic image in the second scan field of view is reconstructed based on the third projection data.

[0112] In the above embodiment, the projection data is stored according to View, each View corresponds to a two-dimensional image of a section, and each View is obtained by the above steps S1101 to S1107 to obtain the third projection data of each View and reconstruct the corresponding tomographic image.

[0113] It should be noted that the steps shown in the above flow or the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0114] In addition, in combination with the medical imaging method provided in the above embodiment, a storage medium can also be provided in this embodiment to realize. The storage medium has a computer program stored thereon; the computer program is executed by a processor to realize any one of the medical imaging methods in the above embodiments.

[0115] In summary, by the above-mentioned embodiments or preferred embodiments, the second detector discrete from the first detector is used to acquire real projection data beyond the standard FOV, and based on the real projection data, the extrapolated data is constrained by data fitting technique or using the information, so that the data of the extrapolated part is more accurate, thus reducing artifacts and improving the accuracy of the extended FOV reconstruction. At the same time, the added second detector module is an isolated one or several units, which greatly reduces the hardware cost of the system compared with the complete detector supporting large FOV, so that good large FOV (i.e. extended FOV) imaging quality can be obtained at a lower cost.

[0116] It should be understood that the specific embodiments described herein are merely exemplary and not intended to limit the application. According to the embodiments provided in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0117] Obviously, the drawings are only some examples or embodiments of the present application, and those skilled in the art can also apply the present application to other similar situations without creative labor according to the drawings. In addition, it can be understood that although the work done in the development process may be complex and long, but for those skilled in the art, some design, manufacture or production changes according to the technical content disclosed in the present application are only routine technical means, and should not be regarded as insufficient disclosure of the present application.

[0118] The above-mentioned embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of patent protection. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A medical imaging system comprising a scan assembly and a processing device, the scan assembly comprising a radiation source and a first detector, wherein, The radiation source is configured to generate radioactive rays, and the first detector is configured to detect the radioactive rays passing through a first scanning field of view; and The scanning assembly further comprises at least one set of second detectors, the second detectors being configured to detect a part of the radioactive rays not passing through the first scanning field of view but passing through a second scanning field of view, wherein the second scanning field of view is larger than the first scanning field of view, and the first scanning field of view is located in the second scanning field of view; wherein the first detector extends along a circumferential line; the second detectors are at least two sets, and the at least two sets of second detectors are symmetrically arranged on the circumferential line of the first detector; The processing device is configured to obtain third projection data corresponding to the second scanning field of view based on the first projection data and the second projection data, and reconstruct a tomographic image in the second scanning field of view based on the third projection data, wherein the first projection data is detected by the first detector, and the second projection data is detected by the second detector; The processing device specifically comprises a fitting unit, a combination unit and a reconstruction unit, wherein the fitting unit is configured to fit fourth projection data corresponding to a residual scanning field of view based on the first projection data and the second projection data, wherein the residual scanning field of view is located outside the first scanning field of view but inside the second scanning field of view; the combination unit is configured to combine the first projection data and the fourth projection data to obtain the third projection data; The fitting unit comprises: an extrapolation subunit configured to extrapolate based on the first projection data to obtain fifth projection data; a weight curve fitting subunit configured to fit a weight curve based on a ratio of the second projection data to projection data corresponding to a position of the second detector in the fifth projection data as a constraint condition; a data generation subunit configured to perform weighted calculation on the second projection data based on the weight curve to obtain the fourth projection data.

2. The medical imaging system of claim 1, wherein, Each set of the second detectors is arranged at intervals with the adjacent first detectors or other second detectors.

3. The medical imaging system of claim 1, wherein, The second detectors comprise a plurality of detector units, and the plurality of detector units are symmetrically arranged on the circumferential line of the first detector and are arranged at intervals with the first detector.

4. The medical imaging system of claim 1, wherein the reconstruction unit is configured to reconstruct a tomographic image in the second scanning field of view based on the third projection data.

5. A medical imaging method characterized by comprises: detecting radioactive rays passing through a first scanning field of view by using a first detector to obtain first projection data, and detecting a part of the radioactive rays not passing through the first scanning field of view but passing through a second scanning field of view by using a second detector to obtain second projection data, wherein the second scanning field of view is larger than the first scanning field of view, and the first scanning field of view is located in the second scanning field of view; wherein the first detector extends along a circumferential line; the second detectors are at least two sets, and the at least two sets of second detectors are symmetrically arranged on the circumferential line of the first detector; acquiring third projection data corresponding to the second scanning field of view based on the first projection data and the second projection data; reconstructing a tomographic image within the second scanning field of view based on the third projection data; the acquiring third projection data based on the first projection data and the second projection data comprises: fitting fourth projection data corresponding to a residual scanning field of view based on the first projection data and the second projection data, wherein the residual scanning field of view is located outside the first scanning field of view but within the second scanning field of view; combining the first projection data and the fourth projection data to obtain the third projection data; the fitting fourth projection data corresponding to a residual scanning field of view based on the first projection data and the second projection data comprises: extrapolating fifth projection data based on the first projection data; fitting a weight curve based on a ratio of projection data of the second projection data to projection data of positions of corresponding second detectors in the fifth projection data as a constraint condition; weighting the second projection data based on the weight curve to obtain the fourth projection data.

6. The medical imaging method of claim 5, characterized in that, Each group of the second detectors is arranged with intervals from adjacent first detectors or other second detectors.

7. A computer-readable storage medium having stored thereon a computer program, characterized in that The computer program, when executed by a processor, implements the steps of the medical imaging method of any one of claims 5 to 6.

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