An imaging system

Abstract

Embodiments of the present application disclose an imaging system. The imaging system comprises a support assembly comprising a detection region for accommodating a subject to be detected; a detector assembly disposed around the detection region for detecting radiation emitted by the subject to be detected when in the detection region; and a processing engine for initializing the detector assembly to activate a portion of the detectors such that the remaining detectors are deactivated.

Description

[0001] Case Analysis

[0002] This application is a divisional application of Chinese application filed on September 26, 2017, with application number 201710883073.3 and entitled "An Imaging Device and a Multimodal Imaging System".

[0003] Priority information

[0004] This application claims priority to the international patent application filed on June 30, 2017, with application number PCT / CN2017 / 091118, entitled "SYSTEM AND METHOD FOR PET IMAGING", the entire contents of which are incorporated herein by reference. Technical Field

[0005] This invention relates to medical imaging technology, and more particularly to a system and method for PET imaging. Background Technology

[0006] Generally, positron emission tomography (PET) detector units are incorporated into various medical devices that utilize PET technology, such as PET scanners, PET-CT scanners, and PET-MRI scanners. The PET detector unit receives radiation (e.g., gamma rays) indirectly generated from the patient's body via tracer molecules and provides information about the location of these tracer molecules, which in turn reflects the patient's functional information. The PET detector unit can generate electrical signals based on the radiation, which can then be detected and used to reconstruct images.

[0007] A PET detector assembly in a PET imaging system may include multiple detector units arranged in an approximately cylindrical configuration. Generally, the more detector units a PET detector assembly includes, the more radiation it can receive, and the higher the sensitivity of the PET imaging system. In some embodiments, a whole-body scan can be performed using a PET imaging system. A detector assembly with a large axial field-of-view (AFOV) can image most of a target (e.g., a patient's entire body) in a single scan, increasing sensitivity and reducing scan time. Furthermore, a large AFOV facilitates dynamic whole-body scanning, offering benefits such as low radiation dose and high speed. Therefore, this application proposes a PET imaging system including a detector assembly with a large AFOV. Summary of the Invention

[0008] The present invention provides an imaging device and a multimodal imaging system, which can increase system sensitivity and shorten scanning time.

[0009] To achieve the above-mentioned objectives, the technical solution provided by this invention is as follows:

[0010] An imaging device includes a support assembly including a detection area for accommodating an object to be detected; and a detector assembly disposed around the detection area for detecting radiation emitted by the object to be detected within the detection area. The detector assembly includes a plurality of detector rings, each detector ring including a scintillator array and a plurality of photoelectric sensors. The plurality of detector rings are mounted on the support assembly along the axial direction to form an axial field of view with a length of not less than 0.75 meters.

[0011] In this invention, the detector assembly includes N detector modules, each detector module including a portion of the plurality of detector rings, and the support assembly includes N support modules. The N detector modules and the N support modules are configured as N imaging units, and each imaging unit includes at least one detector module from the N detector modules and at least one support module from the N support modules, where N is an integer greater than 1.

[0012] In this invention, at least one of the N imaging units is separable.

[0013] In this invention, the support assembly further includes support rails distributed along the axial direction for guiding the assembly of the N imaging units.

[0014] In this invention, a position adjustment component is further included for aligning the N imaging units along the axial direction.

[0015] In this invention, each of the N imaging units has a center, and the deviation between the center of the first imaging unit and the center of the second imaging unit is less than or equal to 1 mm.

[0016] In this invention, the length of the axial field of view of one of the N imaging units is between 0.1 meters and 0.5 meters.

[0017] In this invention, the first imaging unit among the N imaging units has a first lateral diameter, and the second imaging unit among the N imaging units has a second lateral diameter, wherein the first lateral diameter is different from the second lateral diameter.

[0018] In this invention, there is a first spacing between two imaging units in the N imaging units along the axial direction, and the first spacing is less than the width of one scintillator in the scintillator array along the axial direction.

[0019] A multimodal imaging system, characterized in that it comprises: a first imaging device and a second imaging device; the first imaging device comprises one or a combination of several of a computed tomography scanner, an X-ray scanner and an MRI scanner; the second imaging device comprises any of the imaging devices described above.

[0020] The beneficial effects of this invention are as follows:

[0021] It can provide a larger axial field of view, reduce radiation dose, increase system sensitivity and shorten scan time while performing whole-body scans.

[0022] Some of the additional features of this application will be described in the following description. These additional features will be apparent to those skilled in the art upon examination of the following description and the accompanying drawings, or upon understanding the production or operation of the embodiments. The features disclosed herein can be implemented and achieved through the practice or use of various methods, means, and combinations of the specific embodiments described below. Attached Figure Description

[0023] This application can be further described according to exemplary embodiments. The exemplary embodiments can be described in detail with reference to the accompanying drawings. The embodiments described are not limiting exemplary embodiments, wherein the same reference numerals represent similar structures in several views of the drawings, and wherein:

[0024] Figure 1 This is a schematic diagram of an imaging system according to some embodiments of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of a scanner according to some embodiments of the present invention;

[0026] Figure 3 This is a side view of a scanner according to some embodiments of the present invention;

[0027] Figures 4A-4C This is a schematic diagram of the structure of a detector block according to some embodiments of the present invention;

[0028] Figures 5A-5D This is a schematic diagram of the structure of a detection ring according to some embodiments of the present invention;

[0029] Figure 6A This is a schematic diagram of the structure of a scanner according to some embodiments of the present invention;

[0030] Figure 6B This is shown in some embodiments according to the present invention. Figure 6A A schematic diagram of the detector assembly in a two-dimensional plane;

[0031] Figure 6C This is a schematic diagram of the structure of another scanner according to some embodiments of the present invention;

[0032] Figure 6D This is shown in some embodiments according to the present invention. Figure 6C A schematic diagram of the detector assembly in a two-dimensional plane;

[0033] Figure 6E This is a schematic diagram of the structure of a multimodal scanner according to some embodiments of the present invention;

[0034] Figure 7A This is a schematic diagram of a lateral field of view according to some embodiments of the present invention;

[0035] Figure 7B This is a schematic diagram of an axial view according to some embodiments of the present invention;

[0036] Figure 7C This is a schematic diagram illustrating the relationship between the sensitivity of the detector assembly and the imaging system according to some embodiments of the present invention;

[0037] Figure 8A This is a schematic diagram of a cooling assembly according to some embodiments of the present invention;

[0038] Figure 8B This is a schematic diagram of an air-cooled assembly and multiple detector modules according to some embodiments of the present invention;

[0039] Figure 9A This is a schematic diagram of another cooling assembly according to some embodiments of the present invention;

[0040] Figure 9B This is a schematic diagram of a water-cooling assembly and multiple detector modules according to some embodiments of the present invention;

[0041] Figure 9C This is a schematic diagram of another water-cooling assembly and multiple detector modules according to some embodiments of the present invention;

[0042] Figure 10 This is a schematic diagram of a processing engine according to some embodiments of the present invention; and

[0043] Figure 11 This is an exemplary flowchart of a PET imaging process according to some embodiments of the present invention. Detailed Implementation

[0044] In the following detailed description, numerous specific details are set forth by way of example in order to provide a thorough understanding of the related invention. However, it will be apparent to those skilled in the art that the invention can be practiced without such details. To avoid unnecessarily obscuring aspects of the invention, well-known methods, procedures, systems, components, and / or circuits have been described at a higher level (without detail). Various modifications to embodiments of the invention will be apparent to those skilled in the art, and the general principles defined in the invention can be applied to other embodiments and applications without departing from the spirit and scope of the invention. Therefore, the invention is not limited to the embodiments shown, but is accorded the broadest scope consistent with the claims.

[0045] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “described” may also be used to include the plural forms unless the context clearly indicates otherwise. It should be further understood that, as used in this specification, the terms “comprising” and / or “including” mean the presence of the stated integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0046] It should be understood that the terms “system,” “engine,” “unit,” “module,” and / or “block” used in this application are a method of distinguishing different parts, elements, components, sections, or assemblies at different levels in an ascending order. However, these terms may be replaced by other expressions if they achieve the same purpose.

[0047] Generally, as used herein, "module," "unit," or "block" refers to logic embodied in a set of hardware or firmware or software instructions. The modules, units, or blocks described herein can be executed on software and / or hardware and can be stored on any type of non-transitory computer-readable medium or other storage device. In some embodiments, software modules, units, or blocks can be compiled and linked into an executable program. It should be understood that a software module can be invoked from other modules, units, blocks, or itself and / or can be invoked in response to a detected event or interrupt. The software modules / units / blocks configured for execution on a computing device (e.g., such as...) Figure 1The processing engine 120 shown may be provided on a computer-readable medium, such as an optical disc, digital video disc, flash drive, magnetic disk, or any other tangible medium, or as a digital download (and may be stored raw in a compressed or installable format, requiring installation, decompression, or decryption before execution). Software code may be stored, in part or in whole, on a storage device executing the computing device. Software instructions may be embedded in firmware, such as an EPROM. It should be understood that hardware modules, units, or blocks may be included in connected logical components, such as gates and flip-flops, and / or may be included in programmable units such as programmable gate arrays or processors. The modules, units, blocks, or computing device functions described herein may be implemented as software modules / units / blocks, but may be represented in hardware or firmware. Generally, the modules, units, and blocks described herein refer to logical modules, units, and blocks that can be combined with other modules, units, and blocks or divided into sub-modules, sub-units, and sub-blocks, despite their physical organization or storage. The description may apply to a system, engine, or part thereof.

[0048] It should be understood that when a unit, engine, module, or block is referred to as being "on," "connected to," or "coupled to" another unit, engine, module, or block, it may communicate directly with or be present in the other unit, engine, module, or block, unless the context explicitly indicates otherwise. As used in this application, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0049] These and other features of this application, as well as related structural elements and methods of operation and function in combination with manufactured components, will become more apparent from the accompanying drawings and in consideration of the following description, and all of these constitute a part of this application. However, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of this application. It should be understood that the drawings are not to scale.

[0050] For descriptive purposes, the following description is intended to provide a better understanding of PET imaging systems. It should be understood that this is not intended to limit the scope of the invention. Those skilled in the art will be able to make various variations, changes, and / or modifications following the guidance of this invention. These variations, changes, and / or modifications will not depart from the scope of the invention.

[0051] Figure 1This is a schematic diagram of an imaging system 100 according to some embodiments of the present invention. As shown, the imaging system 100 may include a scanner 110, a network 120, one or more terminals 130, a processing engine 140, and a memory 150. In some embodiments, the scanner 110, processing engine 140, memory 150, and / or terminal 130 may be interconnected and / or communicate with each other via wireless connections (e.g., network 120), wired connections, or combinations thereof. The connections between components in the imaging system 100 may vary. For example, as... Figure 1 As shown, scanner 110 can be connected to processing engine 140 via network 120. Alternatively, scanner 110 can be directly connected to processing engine 140. Further, as... Figure 1 As shown, the memory 150 can be connected to the processing engine 140 via the network 120, or directly to the processing engine 140.

[0052] Scanner 110 can scan a target and / or generate multiple data points about the target. In some embodiments, scanner 110 can be a medical imaging device, such as a PET scanner, PET-CT scanner, PET-MRI scanner, etc. Scanner 110 may include a support assembly 111 (e.g., a gantry), a detector assembly 112, a detection area 113, a scan bed 114, an electronics module 115, and a cooling assembly 116. The object to be scanned can be placed on the scan bed 114 for scanning. In this invention, "target" and "object to be scanned" are used interchangeably. Detector assembly 112 can detect radiation events (e.g., gamma photons) emitted from detection area 113. In some embodiments, detector assembly 112 may include one or more detectors. The detectors can be implemented in any suitable manner, such as one or a combination of several of the following: annular, arc-shaped, rectangular, array, etc. See also Figures 5A-5D And its description. In some embodiments, a detector may include one or more crystal elements and / or one or more photomultipliers (e.g., silicon photomultipliers, photomultiplier tubes). See also Figures 4A-4C The scanning bed 114 can position the object to be detected within the detection area 113. The electronics module 115 can acquire electrical signals generated based on radiation events detected by the detector assembly 112. The cooling assembly 116 can cool the detector assembly 112. Further description of the support assembly 111, detector assembly 112, scanning bed 114, electronics module 115, and cooling assembly 116 can be found in related descriptions elsewhere in the invention. For example, see... Figure 2 And its description.

[0053] Network 120 may include any suitable network that enables information and / or data exchange between imaging system 100. In some embodiments, one or more components of imaging system 100 (e.g., scanner 110, terminal 130, processing engine 140, memory 150, etc.) may communicate information and / or data with one or more other components of imaging system 100 via network 120. For example, processing engine 140 may obtain image data from scanner 110 via network 120. As another example, processing engine 140 may obtain user instructions from terminal 130 via network 120. Network 120 may be and / or include public networks (e.g., the Internet), private networks (e.g., local area networks, wide area networks, etc.), wired networks (e.g., Ethernet), wireless networks (e.g., 802.11 networks, Wi-Fi networks, etc.), cellular networks (e.g., LTE networks), Frame Relay networks, virtual private networks (“VPNs”), satellite networks, telephone networks, routers, hubs, converters, server computers, and / or any combination thereof. For example, network 120 may include cable networks, wired networks, fiber optic networks, telecommunications networks, intranets, wireless LANs, metropolitan area networks, public telephone exchanges, and Bluetooth. TM Network, ZigBee TM This includes one or more of the following: a network, a near-field communication network, etc. In some embodiments, network 120 may include one or more network access points. For example, network 120 may include wired and / or wireless network access points, such as base stations and / or internet switching points. Through the aforementioned network access points, one or more components of the imaging system 100 may connect to network 120 to exchange data and / or information.

[0054] Terminal 130 may include one or more of the following: mobile device 130-1, tablet computer 130-2, laptop computer 130-3, etc. In some embodiments, mobile device 130-1 may include one or more of the following: smart home device, wearable device, mobile device, virtual reality device, augmented reality device, etc. In some embodiments, smart home device may include one or more of the following: smart lighting device, smart electrical device control device, smart monitoring device, smart TV, smart camera, walkie-talkie, etc. In some embodiments, wearable device may include one or more of the following: bracelet, shoes and socks, glasses, helmet, watch, clothing, backpack, smart accessory, etc. In some embodiments, mobile device may include one or more of the following: mobile phone, personal digital assistant, gaming device, navigation device, point-of-sale device, laptop computer, tablet computer, desktop computer, etc. In some embodiments, virtual reality device and / or augmented reality device may include one or more of the following: virtual reality helmet, virtual reality glasses, virtual reality patch, augmented reality helmet, augmented reality glasses, augmented reality patch, etc. For example, virtual reality device and / or augmented reality device may include Google Glass. TM Oculus Rift TM HoloLens TM Gear VR TM In some embodiments, terminal 130 may be part of processing engine 140.

[0055] Processing engine 140 can process data and / or information from scanner 110, terminal 130, and / or memory 150. For example, processing engine 140 can process image data and reconstruct images based on the image data. In some embodiments, processing engine 140 can be a single server or a group of servers. The server group can be centralized or distributed. In some embodiments, processing engine 140 can be local or remote. For example, processing engine 140 can read information and / or data stored in scanner 110, terminal 130, and / or memory 150 via network 120. As another example, processing engine 140 can be directly connected to scanner 110, terminal 130, and / or memory 150 to read stored information and / or data. In some embodiments, processing engine 140 can be implemented on a cloud platform. By way of example only, a cloud platform can include one or more of the following: private cloud, public cloud, hybrid cloud, community cloud, distributed cloud, inter-cloud, multi-cloud, etc. In some embodiments, processing engine 140 can be implemented by a computing device. In some embodiments, processing engine 140 or a portion thereof can be integrated into scanner 110.

[0056] In some embodiments, the computing device may include a processor, a memory, an input / output (I / O) port, and a communication port. The processor may execute computer instructions (e.g., program code) and perform the functions of the processing engine 140 according to the techniques described herein. The computer instructions may include, for example, routines, programs, objects, components, data structures, steps, modules, and functions that can perform the specific functions described herein. In some embodiments, the processor may include one or more hardware processors, such as a microcontroller, microprocessor, reduced instruction set computer, application-specific integrated circuit, application-specific instruction set processor, central processing unit, graphics processing unit, physical processor, microcontroller unit, digital signal processor, field-programmable gate array, advanced reduced instruction set computer, programmable logic device, any circuit or processor capable of performing one or more functions, or a combination thereof.

[0057] The memory can store data / information acquired from scanner 110, terminal 130, memory 150, and / or any other component of imaging system 100. In some embodiments, the memory may include one or a combination of several of the following: mass storage, removable memory, volatile read-write memory, and read-only memory (ROM). Mass storage may include disks, optical disks, solid-state drives, and portable storage devices. Volatile read-write memory may include random access memory (RAM). RAM may include dynamic random access memory (DRAM), dual data rate synchronous dynamic random access memory (DDRSDRAM), static random access memory (SRAM), silicon controlled retrieval memory (T-RAM), zero-capacitance random access memory (Z-RAM), etc. ROM may include mask read-only memory (MROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), optical disc read-only memory (CD-ROM), and optical discs such as digital multifunction optical discs. In some embodiments, the memory may store one or more programs and / or instructions to perform the exemplary methods described in this invention.

[0058] The I / O can input and / or output signals, data, information, etc. In some embodiments, the I / O can enable user interaction with the processing engine 140. In some embodiments, the I / O may include an input device and an output device. The input device may include one or a combination of several of the following: keyboard, mouse, touch screen, microphone, etc. Examples of the output device may include one or a combination of several of the following: display device, speaker, printer, projector, etc. The display device may include one or a combination of several of the following: liquid crystal display (LCD), light-emitting diode (LED) based display, flat panel display, curved screen, television equipment, cathode ray tube (CRT), touch screen, etc.

[0059] The communication port can be connected to a network (e.g., network 120) to facilitate data communication. The communication port can establish a connection between the processing engine 140 and the scanner 110, terminal 130, and / or memory 150. The connection can be a wired connection, a wireless connection, any other communication connection that enables data transmission and / or reception, and / or any combination of these connections. Wired connections can include, for example, one or more of the following: electrical cables, optical fibers, telephone lines, etc. Wireless connections can include, for example, Bluetooth. TM Connectivity, Wi-Fi TM Connectivity, WiMax TM The communication port can be one or a combination of several of the following: connectivity, WLAN connectivity, ZigBee connectivity, and mobile network connectivity (e.g., 3G, 4G, 5G, etc.). In some embodiments, the communication port can be and / or include a standardized communication port, such as RS232, RS485, etc. In some embodiments, the communication port can be a specially designed communication port. For example, the communication port can be designed according to the Medical Digital Imaging and Communication (DICOM) protocol.

[0060] Memory 150 may store data, instructions, and / or any other information. In some embodiments, memory 150 may store data obtained from terminal 130 and / or processing engine 140. In some embodiments, memory 150 may store data and / or instructions that processing engine 140 may execute or use to execute the exemplary methods described in this invention. In some embodiments, memory 150 may include one or a combination of mass storage, removable memory, volatile read-write memory, read-only memory (ROM), etc. Mass storage may include disks, optical disks, solid-state drives, mobile storage, etc. Removable memory may include flash drives, floppy disks, optical disks, memory cards, ZIP disks, magnetic tape, etc. Volatile read-write memory may include random access memory (RAM). RAM may include dynamic random access memory (DRAM), dual data rate synchronous dynamic random access memory (DDR SDRAM), static random access memory (SRAM), silicon controlled retrieval memory (T-RAM), zero capacitance random access memory (Z-RAM), etc. The ROM may include a mask read-only memory (MROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), an optical disc read-only memory (CD-ROM), an optical disc of digital multifunction, etc. In some embodiments, the storage device 130 may be implemented using the cloud platform described in this application. For example, the cloud platform may include one or a combination of private cloud, public cloud, hybrid cloud, community cloud, distributed cloud, inter-cloud, multi-cloud, etc.

[0061] In some embodiments, the memory 150 may be connected to the network 120 to communicate with one or more components in the imaging system 100 (e.g., processing engine 140, terminal 130, etc.). One or more components in the imaging system 100 may read data or instructions stored in the memory 150 via the network 120. In some embodiments, the memory 150 may be directly connected to or communicate with one or more components in the imaging system 100 (e.g., processing engine 140, terminal 130, etc.). In some embodiments, the memory 150 may be part of the processing engine 140.

[0062] Figure 2 This is a schematic diagram of the structure of a scanner 110 according to some embodiments of the present invention. Figure 2 As shown, the scanner 110 may include a support assembly 111, a detector assembly 112, a scanning bed 114, an electronic module 115, and a cooling assembly 116.

[0063] Support assembly 111 can support one or more components of scanner 110, such as detector assembly 112, electronic module 115, cooling assembly 116, etc. In some embodiments, support assembly 111 may include a main frame, a frame base, a front cover, and a rear cover (not shown). The front cover may be connected to the frame base. The front cover may be perpendicular to the frame base. The main frame may be mounted on the side of the front cover. The main frame may include one or more support frames to accommodate detector assembly 112 and / or electronic module 115. The main frame may include a circular opening (e.g., detection area 113) to accommodate a scanned target. In some embodiments, the opening of the main frame may be other shapes, including, for example, elliptical. Unless otherwise stated, the terms "object being detected" and "target" are used interchangeably in this invention. The rear cover may be mounted on the side of the main frame opposite the front cover. The frame base may support the front cover, the main frame, and / or the rear cover. In some embodiments, scanner 110 may include a housing (e.g., Figure 3 The housing 302 shown is used to cover and protect the main frame.

[0064] Detector assembly 112 can detect radiation events (e.g., gamma photons) emitted from detection region 113. In some embodiments, detector assembly 112 can receive radiation (e.g., gamma rays) and generate electrical signals. Detector assembly 112 may include one or more detector elements. One or more detector elements may be packaged to form a detector block. Further description of the detector can be found elsewhere in the invention. See, for example... Figures 4A-4C And its description. One or more detector blocks can be packaged to form a detector box. One or more detector boxes can be mounted to form a detector ring. One or more detector rings can be mounted to form a detector module. Further description of the detector ring can be found elsewhere in the description of this invention. See, for example Figures 5A-5D And its description.

[0065] The scanning bed 114 can support the object being inspected and position it at a desired location within the inspection area 113. In some embodiments, the object being inspected can lie on the scanning bed 114. The scanning bed 114 can move under the control of the control module 1004 and reach the desired location within the inspection area 113. In some embodiments, the scanner 110 can have a relatively long axial field of view (see...). Figure 7B For example, an axial field of view of 2 meters. Accordingly, the scanning bed 114 can move along the axis over a wider range (e.g., >2 meters).

[0066] Electronic module 115 can acquire and / or process electrical signals generated by detector assembly 112. Electronic module 115 may include one or more of the following: adder, multiplier, subtractor, amplifier, driver circuit, differential circuit, integrator circuit, counter, filter, analog-to-digital converter, lower limit detection circuit, constant coefficient discriminator circuit, time-to-digital converter, coincidence circuit, etc. Electronic module 115 can convert analog signals related to the energy of radiation received by detector assembly 112 into digital signals. Electronic module 115 can compare multiple digital signals, analyze the multiple digital signals, and determine the interaction position and / or interaction time of radiation received in detector assembly 112. Electronic module 115 can determine one or more coincidence events based on the multiple digital signals. Electronic module 115 can determine image data based on coincidence events and the energy of radiation determined to be coincidence events. In some embodiments, if detector assembly 112 has a large axial field of view (e.g., 0.75 m to 2 m), electronic module 115 can have a high data input rate from multiple detector channels. For example, electronic module 115 can process tens of billions of events per second (e.g., coincidence events, single events, etc.). In some embodiments, the data input rate may be related to the number of detector elements in detector assembly 112.

[0067] Cooling component 116 can generate, transfer, deliver, conduct, or circulate a cooling medium within scanner 110 to absorb heat generated by scanner 110 during imaging. In some embodiments, cooling component 116 can be fully integrated into and become part of scanner 110. In some embodiments, cooling component 116 can be partially integrated into and associated with scanner 110. Cooling component 116 can allow scanner 110 to maintain a suitable and stable operating temperature (e.g., 25°C, 30°C, 35°C, etc.). In some embodiments, cooling component 116 can control the temperature of one or more target components of scanner 110. Target components may include detector component 112, electronics module 115, and / or any other components that generate heat during operation. Cooling medium can be one or a combination of gaseous, liquid (e.g., water), etc. In some embodiments, the gaseous cooling medium may be air. Further description of cooling component 116 can be found in other parts of the invention. See, for example Figures 8A-9B And its description.

[0068] Figure 3 This is a side view of a scanner 110 according to some embodiments of the present invention. Figure 3As shown, multiple detector boxes 304 can be arranged in a ring configuration (also referred to as a detector ring) in cross-section. Detector box 304 may include one or more detector blocks 306. A typical detector block 306 can be found in [reference needed]. Figures 4A-4C The detector housing 304 may be covered and protected by a housing 302. In some embodiments, the housing 302 may be a hollow cylinder. The area surrounded by the detector housing 304 may be a detection area 113. The detection area 113 may accommodate the object to be scanned 308. The object to be scanned 308 may be supported by a scanning bed 114. In some embodiments, if the object to be scanned 308 is within the lateral field of view (FOV), the radiation emitted from the object to be scanned 308 may be detected by the detector housing 304. Further description of the lateral field of view (FOV) can be found in other parts of the invention. See, for example... Figure 7A And its description.

[0069] Figures 4A-4C This is a schematic diagram of the structure of a detector block according to some embodiments of the present invention. Detector block 306 may include one or more crystal elements (e.g., a scintillator crystal array 410) and one or more photoelectric sensor arrays 420.

[0070] like Figure 4A As shown, the crystal element can be configured as a scintillator crystal array 410 (also referred to as a scintillator array 410). The scintillator array 410 may include one or more scintillators (e.g., Figure 4BThe scintillators shown are 410-1, 410-2, 410-3, 410-4, etc. A scintillator can scintillate when a photon of radiation (e.g., gamma rays) strikes it. The scintillator can absorb the energy of the photon of radiation (e.g., gamma rays) and convert the absorbed energy into visible light. In some embodiments, the scintillators of the scintillator array 410 can be arranged in N rows and M columns. N can be an integer greater than 0. M can be an integer greater than 0. In some embodiments, N can be equal to M. In some embodiments, N can be different from M. In some embodiments, an N×M scintillator array can be obtained by locally cutting the crystal using a saw. In some embodiments, cuts of various depths can be made. In some embodiments, the deepest cut can be located at the edge of the detector block 306. In some embodiments, a barrier material (e.g., a reflective film, etc.) can be filled between two adjacent scintillators of the scintillator array 410. Scintillators can use one or more types of crystals, including, for example, one or a combination of several of NaI(TI), BGO, LSO, YSO, GSO, LYSO, LaBr3, LFS, LuAP, LuI3, BaF2, CeF, CsI(TI), CsI(Na), CaF2(Eu), CdWO4, and YAP. Typical physical properties of some scintillators are shown in Table 1.

[0071] Figure 4B The diagram shows a typical 4×4 scintillator array. The scintillator array 410 may have a first surface and a second surface, the second surface being opposite to the first surface. The first surface may be a common surface (e.g., a top surface) at one end of a plurality of scintillators in the scintillator array 410. The second surface may be a common surface (e.g., a bottom surface) at the other end of a plurality of scintillators in the scintillator array 410. In some embodiments, the first surface or the second surface may face the detection region 113.

[0072] The photoelectric sensor array 420 may include one or more photoelectric sensors (e.g., Figure 4CThe photoelectric sensors shown are 420-1, 420-2, 420-3, 420-4, etc. Photoelectric sensors can convert optical signals (e.g., light output from a scintillator) into electrical signals. In some embodiments, the photoelectric sensor can be a photomultiplier tube, a silicon photomultiplier, etc. In some embodiments, the photoelectric sensor can be a single-channel photoelectric sensor or a multi-channel photoelectric sensor. The photoelectric sensor array 420 can be connected to the scintillator array 410. In some embodiments, the photoelectric sensor array 420 can be mounted on a first surface or a second surface of the scintillator array 410. In some embodiments, two photoelectric sensor arrays can be mounted on the first surface and the second surface of the scintillator array 410, respectively. In some embodiments, the photoelectric sensors of the photoelectric sensor array 420 can be arranged in N' rows and M' columns. N' can be an integer greater than 0 but not greater than N. M' can be an integer greater than 0 but not greater than M. In some embodiments, one photoelectric sensor can be connected to one or more scintillators of the scintillator array 410 simultaneously.

[0073] Table 1. Typical physical properties of scintillators in PET (energy resolution and attenuation coefficient were measured at 511 keV).

[0074]

[0075] It should be noted that the above description of detector block 306 is for illustrative purposes only and is not intended to limit the scope of the invention. Those skilled in the art will be able to make various changes and modifications to detector module 200 under the guidance of this invention. However, these changes and modifications will not depart from the scope of the invention. For example, one or more light guides may be included between scintillator array 410 and photoelectric sensor array 420.

[0076] Figures 5A-5D This is a schematic diagram illustrating the structure of a detector ring according to some embodiments of the present invention. In some embodiments, multiple detector boxes (or detector blocks) may be arranged in a full-ring array or a partial-ring array. A detector ring may include detector blocks of one or more rings. For example, as... Figures 5A-5D As shown, a detector ring may include four detector blocks. A detector ring may have a diameter of 70 cm to 100 cm. In some embodiments, a detector ring with a full-ring configuration may be configured in a circular form (see...). Figure 5A ), hexagonal form (see) Figure 5D The detector ring can be in elliptical or other polygonal form. In some embodiments, the detector ring with a partial ring configuration can be implemented based on two or more detector blocks. The detector blocks can be curved or flat. Figure 5BThe partial ring configuration shown has two curved detector blocks with an angle variation of 15° between them. Figure 5C The illustrated partial-ring configuration detector ring has six uniformly spaced curved detector blocks. In some embodiments, depending on the partial-ring geometry, a partial-ring configuration detector ring can achieve a larger lateral field of view compared to a full-ring configuration detector ring, provided the total volume of crystal material is the same. In some embodiments, multiple detector rings can be axially continuous to form a detector assembly with a large axial length (e.g., 0.75 m to 2 m). In a detector assembly, at least one detector ring can have a full-ring configuration and / or at least one detector ring can have a partial-ring configuration. Detector assemblies with large axial lengths can have large axial field of view (AFOV) (e.g., 0.75 m to 2 m). In some embodiments, detector assemblies with large axial lengths can enable whole-body scanning.

[0077] Figure 6A This is a schematic diagram of the structure of a scanner 110 according to some embodiments of the present invention. Figure 6A As shown, the scanner 110 may include a support assembly 602, a detector assembly 604, and a scanning bed 606. The support assembly 602 may support other components in the scanner 110, including, for example, the detector assembly 604 and a cooling assembly (…). Figure 6A (Not shown in the image). For example, the support component 602 can support the detector component 604 and / or drive the detector component 604 to move, such as rotate, translate, or rock. In some embodiments, the support component 602 may include a hole (e.g., detection area 113). The hole may have a first lateral diameter (or hole lateral diameter) and a first axial length (or hole axial length). The hole axial length can be defined along a path such as... Figure 6A The arrow indicates the Z-axis direction (i.e., axial direction), which is the distance from one end of the hole to the opposite end. The axial length of the hole can also refer to the length of the support assembly 602 along the Z-axis direction. In some embodiments, the axial length of the hole in the support assembly 602 can range from 0.75 meters to 2 meters. In some embodiments, the axial length of the hole in the support assembly 602 can exceed 2 meters.

[0078] Detector assembly 604 may include one or more detector modules (e.g., such as...) Figure 6BThe detector modules shown are 604-1, 604-2, ..., 604-(N-1), 604-N. A detector module may include one or more detector blocks. In some embodiments, the detector blocks may be mounted on the inner wall of the support assembly 602 in a certain number of rings. In some embodiments, the detector assembly 604 may have a second lateral diameter (or lateral diameter of the detector assembly) and a second axial length (or axial length of the detector assembly). The axial length of the detector assembly may be defined as the distance along the Z-axis from one end of the detector assembly 604 to the opposite end of the detector assembly 604. The axial length of the detector assembly may also refer to the length of the detector assembly 604 in the Z-axis direction. The lateral diameter of the detector assembly may be defined as the diameter of the detection ring in a lateral plane perpendicular to the Z-axis direction.

[0079] In some embodiments, the axial length of the detector assembly is related to the axial field of view (AFOV) of the scanner 110. As used herein, the axial field of view (AFOV) can refer to the maximum length along the Z-axis of the detector assembly 604 that can effectively detect coincident events (see [link to documentation]). Figure 7B The greater the axial length of the detector assembly 604, the greater the axial field of view (AFOV) of the scanner 110. For example, the axial length of the detector assembly 604 can range from 0.75 meters to 2 meters. In some embodiments, the axial length of the detector assembly 604 can be greater than 0.75 meters, or greater than 1 meter, or greater than 1.5 meters, or greater than 2 meters. Accordingly, the axial length of the AFOV can be greater than 0.75 meters, or greater than 1 meter, or greater than 1.5 meters, or greater than 2 meters. Multiple organs of the subject (e.g., head, heart, lungs, liver, stomach, pancreas, bladder, knees, etc.) can be scanned in a single scan. Again, for example, the axial length of the detector assembly 604 can range from 0.75 meters to 1.25 meters. The area between the head and thigh of the subject (e.g., an adult patient) can be scanned in a single scan, or a whole-body scan of a subject with a smaller size (e.g., a child) can be achieved in a single scan. For example, the axial length of the detector assembly 604 can range from 1.25 meters to 2 meters, or exceed 2 meters. In some embodiments, the axial length of the hole in the support assembly 602 can be equal to or greater than the axial length of the detector assembly 604.

[0080] The lateral diameter of detector assembly 604 can be related to the lateral field of view (FOV) of scanner 110. The lateral field of view (FOV) can be related to the acceptance angle of coincidence events detected by the scintillator of detector assembly 604 in the lateral plane (see...). Figure 7A This relates to the lateral diameter of the detector assembly 604. The larger the lateral diameter of the detector assembly 604, the larger the lateral field of view (FOV) of the scanner 110. The lateral diameter of the detector assembly 604 can be smaller than the lateral diameter of the aperture.

[0081] Figure 6B This is shown in some embodiments according to the present invention. Figure 6A A schematic diagram of the detector assembly 604 in a two-dimensional plane. (See diagram below.) Figure 6B As shown, the support component 602 can be an integrated structure. The detector component 604 can include one or more detector modules (e.g., detector modules 604-1, 604-2, ..., 604-(N-1), 604-N, etc.). Multiple detector modules can be mounted on the support component 602. Two adjacent detector modules can have a first spacing (or module spacing) d1 in the Z-axis direction. In some embodiments, the first spacing d1 between two adjacent detector modules can be less than 20 mm (e.g., 1 mm, 2 mm, 5 mm, 10 mm, etc.). In some embodiments, the first spacing d1 between any two adjacent detector modules in the detector component 604 can be less than or equal to 20 mm, or less than or equal to 15 mm, or less than or equal to 10 mm, or less than or equal to 8 mm, or less than or equal to 5 mm, or less than or equal to 3 mm, or less than or equal to 2 mm, or less than or equal to 1 mm. In some embodiments, the first spacing d1 can be less than the width of the scintillator in the Z-axis direction. In some embodiments, the first spacing d1 between different detector modules can be the same or different. For example, two adjacent detector modules (e.g., the first detector module and the second detector module) can be 1 mm apart, while two adjacent detector modules (e.g., the third detector module and the fourth detector module) can be 5 mm apart. As another example, the detector modules in detector assembly 604 can be evenly spaced in the Z-axis direction.

[0082] The detector module may include, for example Figure 4A , 4B And / or one or more detector blocks (or detector units, detector boxes) as described in 4C. A detector block (or detector unit, detector box) can be configured as one or more detector rings in a detector module (e.g., detector rings with a full-ring configuration and / or detector rings with a partial-ring configuration). In a detector module, two adjacent detector rings may have a second spacing (or ring spacing) d2 in the Z-axis direction. In some embodiments, the second spacing d2 may be less than 1 mm (e.g., 0.1 mm, 0.2 mm, 0.5 mm, etc.). In some embodiments, the second spacing d2 between two adjacent detector rings may be less than 5 mm. In some embodiments, the second spacing d2 between two adjacent detector rings may be less than 2 mm, or less than 10 mm, or less than 20 mm. In some embodiments, the first spacing d1 between two adjacent detector modules may be the same as or different from the second spacing d2 between two adjacent detector rings.

[0083] In some embodiments, the number of detector blocks (or detector units, detector boxes) in different detector modules may be the same or different. For example, detector module 604-1 and detector module 604-2 may include the same number of detector blocks. As another example, detector module 604-(N-1) and detector module 604–N may have different numbers of detector blocks. In some embodiments, the size of detector blocks (or detector units, detector boxes) in different detector modules may be the same or different. In some embodiments, the dimensions of detector blocks (or detector units, detector boxes) in the same detector module may be the same or different. In some embodiments, the lateral diameter of the detection ring in different detector modules may be the same or different. In some embodiments, the lateral diameter of the detection ring in the same detector module may be the same or different.

[0084] Figure 6C This is a schematic diagram of the structure of a scanner 110 according to some embodiments of the present invention. Figure 6C As shown, the scanner 110 may include a support assembly 602, a detector assembly 604, and a scanning bed 606. In some embodiments, the support assembly 602 may be an integrated structure. The support assembly 602 may include one or more support modules, such as support module 602-1, support module 602-2, ..., support module 602-(N-1), support module 602-N, etc. The detector assembly 604 may include one or more detector modules, such as... Figure 6A The detector modules 604-1, 604-2, ..., 604-(N-1), 604-N, etc. are mentioned. Figure 6CAs shown, multiple detector modules can be mounted on multiple support modules respectively. For example, detector module 604-1 can be mounted on support module 602-1, detector module 604-2 can be mounted on support module 602-2, detector module 604-(N-1) can be mounted on support module 602-(N-1), and detector module 604-N can be mounted on support module 602-N. In some embodiments, two adjacent support modules can be connected to each other by means of welding, riveting, bolting, etc. In some embodiments, a detector module can be assembled onto a support module to form an imaging unit (e.g., a PET unit). In some embodiments, different imaging units can be used to scan different parts of the object being detected. In some embodiments, the length of the axial field of view (AFOV) of an imaging unit can range from 0.16 meters to 0.3 meters. In some embodiments, the length of the axial field of view (AFOV) of an imaging unit can range from 0.1 meters to 0.5 meters. In some embodiments, the length of the axial field of view (AFOV) of an imaging unit can be equal to or greater than the axial width of a detector block. In some embodiments, one or more imaging units may be assembled in the scanner 110 along the Z-axis to obtain a large axial field of view (AFOV) (e.g., 0.75 m to 2 m) for whole-body scanning (see...). Figure 6E In some embodiments, the axial length of the axial field of view (AFOV) may be greater than 0.75 meters, or greater than 1 meter, or greater than 1.5 meters, or greater than 2 meters.

[0085] In some embodiments, each imaging unit may have a center (e.g., a center in the lateral plane). In some embodiments, the deviation between the center of the first imaging unit (i.e., the imaging unit formed by assembling the support module 602-1 and the detector module 604-1) and the center of the second imaging unit (i.e., an imaging unit other than the first imaging unit, such as the imaging unit formed by assembling the support module 602-N and the detector module 604-N) may be less than or equal to x millimeters. In some embodiments, x may be less than 1 millimeter. In some embodiments, x may range from 0.2 millimeters to 1 millimeter. In some embodiments, x may be less than 0.2 millimeters. In some embodiments, the deviation between the center of the first imaging unit and the center of the second imaging unit adjacent to the first imaging unit is less than or equal to 1 millimeter, or less than or equal to 0.5 millimeters, or less than or equal to 0.2 millimeters. In some embodiments, the lateral plane of one or more imaging units may be adjusted such that the lateral plane of the imaging unit is substantially parallel to the lateral plane of the scanner 110.

[0086] Figure 6D This is shown in some embodiments according to the present invention. Figure 6CA schematic diagram of the detector assembly 604 in a two-dimensional plane. (See diagram below.) Figure 6D As shown, a first spacing d1 may exist between two adjacent detector modules. In some embodiments, the first spacing d1 may be smaller than the width of the scintillator in the Z-axis direction. The second spacing d2 between adjacent detector rings may be similar to... Figure 6B As described, a third spacing d3 may exist between two adjacent support modules. In some embodiments, the third spacing d3 may be smaller than the first spacing d1. In some embodiments, the third spacing d3 between two adjacent support modules may be less than 20 mm. In some embodiments, the third spacing d3 between two adjacent support modules may be less than 5 mm. In some embodiments, the third spacing d3 between two adjacent support modules may be less than 2 mm. In some embodiments, the first spacing d1, the second spacing d2, and / or the third spacing d3 may be the same or different. For example, the first spacing d1 and the second spacing d2 may be equal. As another example, the third spacing d3 may be greater than the second spacing d2.

[0087] Figure 6E This is a schematic diagram of the structure of a multimodal scanner 110 according to some embodiments of the present invention. Figure 6E As shown, the multimodal scanner 110 may include a first scanner 610, a PET scanner 620, a position adjustment assembly 630, a track 640, and a detection area (not shown).

[0088] In some embodiments, the first scanner 610 may include one or a combination of several of a computed tomography (CT) scanner, an X-ray scanner, an MRI scanner, etc. The first scanner 610 may be positioned in front of the PET scanner 620 in the Z-axis direction. In some embodiments, the first scanner 610 may include an X-ray emitting device and a first detector assembly. The first detector assembly may form a first portion of the detection area. The first detector assembly may be used to detect at least a portion of the X-ray beam emitted by the X-ray emitting device and passing through the object being detected within the first portion of the detection area.

[0089] The PET scanner 620 may include one or more PET units (e.g., PET unit 621, PET unit 622, PET unit 623, PET unit 624, PET unit 625, PET unit 626, PET unit 627, PET unit 628, etc.). In some embodiments, the PET unit may include a detector module (e.g., such as...). Figure 6C and 6D The detector modules 604-1, 604-2, ..., 604-N shown, and the support modules (e.g., such as...) Figure 6C and 6DThe support modules 602-1, 602-2, ..., 602-N are shown. In some embodiments, one or more detector modules of the PET scanner 620 may form a second portion of the detection area. Two adjacent PET units may be connected by one or a combination of methods such as bolts, riveting, screws, welding, etc. In some embodiments, two adjacent PET units may have a spacing 650, which may range from 1 mm to 20 mm. In some embodiments, the spacing 650 between two adjacent PET units may range from 2 mm to 10 mm. In some embodiments, the spacing 650 between two adjacent PET units may range from 2 mm to 5 mm. In some embodiments, the spacing 650 may be less than the width of the scintillator in the Z-axis direction. In some embodiments, the length of the axial field of view (AFOV) of a PET unit may range from 0.16 m to 0.3 m. In some embodiments, the length of the axial field of view (AFOV) of a PET unit may range from 0.1 m to 0.5 m. In some embodiments, the length of the axial field of view (AFOV) of an imaging unit may be equal to or greater than the axial width of a detector block.

[0090] The position adjustment component 630 can be used to adjust the position of the PET scanner 620 (e.g., multiple PET cells) and / or the first scanner 610 so that the PET scanner 620 (e.g., multiple PET cells) and / or the first scanner 610 are aligned in the Z-axis direction and / or the lateral plane. In some embodiments, the position adjustment component 630 may include one or more position adjustment modules. A position adjustment module may be associated with one of the multiple PET cells. The position adjustment module can be used to move the PET cell associated with the position adjustment module.

[0091] In some embodiments, each PET unit may have a center (e.g., a center in a transverse plane). In some embodiments, the deviation between the center of the first PET unit (e.g., PET unit 621) and the center of the second imaging unit (i.e., PET units other than the first PET unit, such as PET units 622, 623, 624, 625, 626, 627, 628, etc.) may be less than or equal to y millimeters. In some embodiments, y may be less than 1 millimeter. In some embodiments, y may range from 0.2 millimeters to 1 millimeter. In some embodiments, y may be less than 0.2 millimeters. In some embodiments, the deviation between the center of the first PET unit (e.g., PET unit 621) and the center of the second PET unit (e.g., PET unit 622) located near the first PET unit may be less than or equal to 1 millimeter, or less than or equal to 0.5 millimeters, or less than or equal to 0.2 millimeters. In some embodiments, the deviation of the centers of different PET units may be adjusted by a position adjustment component 630. In some embodiments, the center deviation between the first scanner 610 and the PET scanner 620 may be adjusted by another position adjustment component (not shown). In some embodiments, the lateral planes of one or more PET cells can be adjusted such that the lateral planes of the PET cells are substantially parallel to the lateral plane of the multimodal scanner 110. In some embodiments, the lateral planes of the first scanner 610 and / or the PET scanner 620 can be adjusted such that the lateral planes of the first scanner 610 and / or the PET scanner 620 are substantially parallel to the lateral plane of the multimodal scanner 110.

[0092] Rail 640 may include support rail 641 and service rail 642. In some embodiments, support rail 641 may be used to support position adjustment assembly 630. Support rail 641 may guide the assembly or disassembly of PET cells. In some embodiments, support rail 641 may include one or more sliders. Position adjustment assembly 630 may move along said one or more sliders. In some embodiments, one or more PET cells may be separable. PET cells may be assembled to or disassembled from PET scanner 620 via said sliders. Service rail 642 may be used to support multimodal scanner 110. In some embodiments, service rail 642 may include a plurality of wheels. Multimodal scanner 110 may move with said wheels. In some embodiments, service rail 642 may be detachable from multimodal scanner 110. Regarding the multimodal scanner 110, references can be made to, for example, U.S. Patent Application No. 15 / 609,251, filed March 31, 2017, entitled “SYSTEM AND METHOD FORMEDICAL IMAGING” and Chinese Patent Application No. 201710075120.1, filed February 13, 2017, entitled “PET Imaging Apparatus and PET-CT Imaging Apparatus”, the contents of which are incorporated herein by reference.

[0093] like Figures 6A-6E As shown, PET scanners with a large axial field of view (AFOV) (e.g., 0.75 m to 2 m) can perform whole-body scans. This enables low-dose, rapid, and dynamic whole-body scans. For scans using a conventional PET scanner, the injection dose of fluorodeoxyglucose can be 10 mCi, corresponding to a radiation dose of 7 mSv. For PET scanners with a large axial field of view (AFOV) (e.g., 0.75 m to 2 m), the radiation dose per scan can be less than 1 mSv or less than 5 mSv, approximately one-tenth of the current level. PET scanners with a large axial field of view (AFOV) (e.g., 0.75 m to 2 m) can be used for physical examinations, pediatric scans, etc. For PET-CT scanners, the radiation dose for whole-body CT scans can be 2 mSv to 15 mSv (120 kV, 20-150 mAs / slice), for example, the radiation dose can be less than 5 mSv. The radiation dose of CT scans can be reduced through dose adjustment, iterative reconstruction, and using PET localization images instead of CT localization images.

[0094] In some embodiments, the sensitivity of a PET scanner with a large axial field of view (AFOV) (e.g., 0.75 m to 2 m) may be not less than 400 cps / kBq or not less than 300 cps / kBq. In some embodiments, the scanning time for scanning may be less than 30 seconds. In some embodiments, the scanning time for whole-body scanning may be within 8 seconds to 20 seconds. A whole-body scan can be completed in one breath-hold. In some embodiments, rapid scanning can reduce motion artifacts. In some embodiments, the spatial resolution of a PET scanner with a large axial field of view (AFOV) (e.g., 0.75 m to 2 m) may be not less than 5 mm, or not less than 4 mm, or not less than 3 mm, or not less than 2 mm, or not less than 1 mm. For example, the spatial resolution of a PET scanner with a large axial field of view (AFOV) (e.g., 0.75 m to 2 m) may be 2.8 mm, or 2.5 mm, or 2 mm, or less than 2 mm.

[0095] It should be noted that the above regarding Figures 6A-6E The description is for illustrative purposes only and is not intended to limit the scope of the invention. Those skilled in the art will recognize that various changes or modifications can be made to the invention. However, these changes and modifications will not depart from the scope of the invention. For example, Figures 6A-6D The scanner 110 may further include one or more components, such as one or more electronic modules. For example, Figure 6E The number of PET cells can be any integer greater than 0 (e.g., 8). For example, Figure 6C and 6D The number of imaging units can be any integer greater than 0 (e.g., 8 or an integer between 2 and 20).

[0096] Figure 7AThis is a schematic diagram of the lateral field of view (FOV) according to some embodiments of the present invention. In some embodiments, a detector unit (e.g., detector unit 701) of the detector ring 700 can be connected to a plurality of opposing detector units in its lateral plane via a coincidence circuit (not shown) of an electronic module 115 having a time window. In some embodiments, the time window can be set from 1 nanosecond to 20 nanoseconds depending on the type of detector. In some embodiments, the detector ring 700 can have P detector units. In some embodiments, detector unit 701 can detect coincidence events with Q detector units on opposite sides via a coincidence circuit. In some embodiments, Q can be a fraction of P, such as Q = P / 3, Q = P / 2, Q = 2P / 3, etc. Therefore, Q projections can be used for detector unit 701. The Q projections used for detector unit 701 can form a receiving angle 707 in the lateral plane. In some embodiments, similar to detector unit 701, each detector unit can form a receiving angle in the lateral plane, and the receiving angles of all detector units in the detector ring 700 can form the lateral field of view (FOV). In some embodiments, the lateral field of view (FOV) can be the overlapping area formed by the projections of all detector elements in the detector ring 700. The more layers of overlap between detector elements, the larger the acceptance angle, and therefore the larger the lateral field of view (FOV) of the imaging system 100. In some embodiments, the lateral field of view (FOV) can be determined by user input or by the default settings of the imaging system 100. In some embodiments, the lateral field of view (FOV) can be determined based on the performance of the imaging system 100, such as sensitivity, spatial resolution, temporal resolution, response time, etc. In some embodiments, the lateral field of view (FOV) can be determined based on the configuration of the detector ring 700, such as the size of the detector elements, the thickness of the detector elements, the diameter of the detector ring 700, the spacing between two adjacent detector elements of the detector ring 700, etc. In some embodiments, the lateral field of view (FOV) can be related to the diameter of the detector ring 700 and / or the lateral acceptance angle. In some embodiments, the diameter of the lateral field of view (FOV) can range from 60 cm to 90 cm.

[0097] Figure 7BThis is a schematic diagram of an axial field of view (FOV) according to some embodiments of the present invention. In some embodiments, a detector unit (e.g., detector unit A) of detector assembly 112 can be connected to a plurality of opposing detector units in an axial plane via a coincidence circuit (not shown) of an electronic module 115 having a time window, the axial plane referring to the axial plane containing the center point of the detection ring and an axial plane parallel to the axial plane containing the center point. In some embodiments, the time window can be set from 1 nanosecond to 20 nanoseconds depending on the type of detector. In some embodiments, detector assembly 112 may have E rings of detector units. In some embodiments, detector unit A can detect coincidence events with F detector units opposite to detector unit A in the axial plane. In some embodiments, F can be a fraction of E, such as F = E / 3, F = E / 2, F = 2E / 3, F = E, etc. Therefore, F projections can be used for detector unit A. Each of the F projections can form an angle relative to the transverse plane 702. The projection can refer to the line connecting two detectors that detected a coincidence event. The largest angle of the F projections (e.g., α) can constitute the axial acceptance angle. Detector unit A and detector unit B (or detector unit A' and detector unit B') can be positioned on opposite sides of the transverse plane 702. Detector unit A and detector unit B (or detector unit A' and detector unit B') can together form an axial acceptance angle (2α, as shown). The distance between detector unit A and detector unit B (or detector unit A' and detector unit B') can then form an axial field of view (AFOV). In some embodiments, the axial field of view (AFOV) can be determined based on user input or the default settings of the imaging system 100. In some embodiments, the axial field of view (AFOV) can be determined based on the performance of the imaging system 100, such as sensitivity, spatial resolution, temporal resolution, response time, etc. In some embodiments, the axial field of view (AFOV) can be determined based on the configuration of the detector assembly 112, such as the size of the detector unit, the axial thickness of the detector ring, the diameter of the detector ring, the spacing between two adjacent detector rings, the axial length of the detector assembly 112, etc. In some embodiments, the axial field of view (AFOV) can be less than 0.75 meters. In some embodiments, the axial field of view (AFOV) can be greater than 0.75 meters, for example, from 0.75 meters to 2 meters. In some embodiments, for a large axial field of view (AFOV) (e.g., from 0.75 meters to 2 meters), the time window of the coincidence circuit can be relatively large (e.g., 10 nanoseconds, 20 nanoseconds, 25 nanoseconds, etc.). In some embodiments, for a large axial field of view (AFOV) (e.g., from 0.75 meters to 2 meters), the coincidence circuits between different detector units can have different time windows.For example, detector units far from the lateral plane 702 (e.g., detector unit A and detector unit B') may have a time window of 20 nanoseconds, while detector units close to the lateral plane 702 (e.g., detector unit C and detector unit C') may have a time window of 1 nanosecond.

[0098] Figure 7C This is a schematic diagram illustrating the relationship between the detector assembly 112 and the sensitivity of the imaging system according to some embodiments of the present invention. Figure 7C As shown, the imaging system 100 may include eight PET units (e.g., such as...). Figure 6EThe PET cells 621, 622, 623, 624, 625, 626, 627, and 628 are shown. In some embodiments, the length of the axial field of view (AFOV) of each of the eight PET cells may be 0.25 meters. It should be noted that the AFOV of each of the eight PET cells is for illustrative purposes only and is not intended to limit the scope of the invention. Triangular regions (e.g., 0-0, 1-1, 2-2, 3-3, 4-4, 5-5, 6-6, and 7-7) may refer to the sensitivity of a PET cell to detect coincidence events. For example, the triangular region 0-0 may refer to the sensitivity of PET cell 621 to detect coincidence events. Diamond-shaped regions (e.g., 0-1, 1-2, 2-3, 3-4, 4-5, 5-6, 6-7, etc.) may indicate the sensitivity of different PET cells (e.g., two adjacent PET cells) to detect overlapping coincidence events. For example, the diamond-shaped region 0-1 (or 1-0) can refer to the sensitivity of cross coincidence events detected by PET units 621 and 622. The line of response (LOR) between the PET units can be set by the user via terminal 130. As described herein, the line of response (LOR) refers to the line connecting two scintillators capable of detecting a coincidence event. The tilt angle of the line of response (LOR) (i.e., the coincidence line) relative to the major axis (i.e., the axial direction) of the PET unit is related to the sensitivity of the imaging system 100. The larger the tilt angle of the line of response (LOR), the higher the sensitivity of the imaging system 100. In some embodiments, the tilt angle of the line of response (LOR) can be defined by the offset of the line of response. In some embodiments, if it is necessary to process coincidence events detected by two adjacent PET cells, the offset of the response line can be equal to 0, and the sensitivity of the imaging system 100 can be related to the cumulative sensitivity in the triangular regions (e.g., 0-0, 1-1, 2-2, 3-3, 4-4, 5-5, 6-6, and 7-7). The greater the offset, the higher the sensitivity of the imaging system 100.

[0099] Figure 8A This is a schematic diagram of a cooling assembly 116 according to some embodiments of the present invention. The cooling assembly 116 can use a cooling medium such as gas, liquid, or a combination of several of these. The description of the cooling assembly 116 herein is for illustrative purposes and does not limit the scope of the invention. Figure 8A and Figure 8BThe cooling component 116 may use a gaseous cooling medium, or simply cooling gas. The cooling component 116 may generate, transfer, deliver, conduct, or circulate cooling gas within the scanner 110 to absorb heat generated by the scanner 110 during imaging. In some embodiments, the cooling component 116 may be fully integrated into and become part of the scanner 110. In some embodiments, the cooling component 116 may be partially integrated into and associated with the scanner 110. For example, a portion of the cooling component 116 (e.g., cavity 820) may be integrated into the scanner 110, while another portion of the cooling component 116 (e.g., cooler 810) may be configured externally to the scanner 110. The cooling component 116 may control the scanner 110 to maintain a suitable and / or stable operating temperature. In some embodiments, the cooling component 116 may control the temperature at one or more target locations on the scanner 110. Target locations may include the detector assembly 112, the electronics module 115, and / or any other components that may generate heat. Figure 8A As shown, the cooling assembly 116 may include a cooler 810 and a cavity 820.

[0100] Cooler 810 can process or cool a cooling medium. The cooling medium can be introduced into cavity 820 to absorb heat from scanner 110 (e.g., detector assembly 112). Typical gaseous cooling media may include one or a combination of inert gases, nitrogen, carbon dioxide, air, etc. In some embodiments, cooler 810 can cool the cooling medium that has absorbed heat from scanner 110.

[0101] As shown in the figure, the cooler 810 may include a compressor 812 and a blower 814. The compressor 812 can increase the pressure of the coolant to cause it to condense, and the heat in the coolant can be dissipated through heat sinks. In some embodiments, the condensed coolant can be evaporated through an evaporator (not shown) and absorb heat from the cooling gas; the heated cooling gas can then be cooled for reuse. The cooling gas can be driven by the blower 814 and circulated within the cooling assembly 116. In some embodiments, the compressor 812 may include one or a combination of centrifugal compressors, axial compressors, reciprocating compressors, rotary compressors, etc. For example, an axial compressor may include a diagonal or mixed-flow compressor, an axial flow compressor, etc. A reciprocating compressor may include a double-acting compressor, a single-acting compressor, etc. A rotary compressor may include a rotary vane compressor, a scroll compressor, a screw compressor, an ionic liquid piston compressor, a vane compressor, a liquid ring compressor, etc. The blower 814 (also referred to as a fan) can drive the cooling gas to flow within the cavity 820. In some embodiments, the blower 814 may include a mechanical bearing blower, a magnetic levitation blower, a gas-bearing levitation blower, etc. In some embodiments, one or more parameters of the cooling process, such as the flow rate of the cooling gas, can be determined and / or adjusted by the blower 814. For example, the flow rate of the cooling gas can be adjusted by adjusting the rotational speed of the blower 814.

[0102] Cavity 820 can be used to deliver cooling gas to one or more target locations of scanner 110 (e.g., around detector assembly 112). Figure 8A As shown, cavity 820 may include one or more air cavities 822, compressor cavity 824, and one or more cooling cavities 826. Compressor cavity 824 may be configured to receive cooled gas processed by compressor 812. In some embodiments, compressor cavity 824 may house compressor 812. In some embodiments, compressor cavity 824 may be connected to compressor 812 via, for example, a pipe. Cooling cavity 826 may surround heat-generating components (e.g., detector assembly 112 of scanner 110, electronic module 115, etc.) to cool the heat-generating components.

[0103] Air chamber 822 can provide space for gas exchange between compressor chamber 824 and one or more cooling chambers 826. For example, air chamber 822 may include one or more inlet chambers connecting compressor chamber 824 and cooling chamber 826. Cooled gas leaving compressor 812 can be driven by blower 814 to flow from compressor chamber 824 to cooling chamber 826 through the inlet chamber. As another example, air chamber 822 may include one or more outlet chambers connecting compressor chamber 824 and cooling chamber 826. Gas that has absorbed heat from heat-generating components (e.g., detector assembly 112 of scanner 110, electronic module 115, etc.) can be driven to flow from cooling chamber 826 to compressor chamber 824 through the outlet chamber.

[0104] In some embodiments, the configuration between the detector assembly 112 and the cooling chamber 826 can be varied. For example, one detector module of the detector assembly 112 may have one cooling chamber 826. As another example, multiple detector modules of the detector assembly 112 (e.g., all detector modules) may share one cooling chamber 826. In some embodiments, a first number of detector modules may share one cooling chamber 826. This first number may be greater than 2 but less than the number of detector modules in the detector assembly 112.

[0105] In some embodiments, the configuration between the air cavity 822 and the cooling cavity 826 can be varied. For example, one of the cooling cavities 826 may have one air cavity 822. As another example, multiple (e.g., all) cooling cavities 826 may share a single air cavity 822. In some embodiments, a second number of cooling cavities 826 may share a single air cavity 822. This second number may be greater than 2 but less than the number of cooling cavities 826.

[0106] Figure 8B This is a schematic diagram of an air-cooled assembly and multiple detector modules according to some embodiments of the present invention.

[0107] Cooler 810 can provide such Figure 8AThe described cooling gas. Controller 803 can control the cooler 810, cooling chamber 805, inlet chamber, and / or outlet chamber. In some embodiments, controller 803 can be integrated into control module 1004. In some embodiments, controller 803 can control parameters of the cooling gas in the cooler 810, cooling chamber 805, inlet chamber, and / or outlet chamber according to, for example, instructions set by a user via terminal 130. The parameters of the cooling gas may include one or a combination of pressure, temperature, cooling gas flow rate, heat generation rate, cooling load to remove generated heat, cooling rate, etc. For example, controller 803 can adjust the pressure (e.g., gas pressure) of the cooling gas in the inlet chamber (e.g., inlet chamber 1, inlet chamber 2, ..., inlet chamber N). As another example, controller 803 can control the flow rate of the cooling gas in one of a plurality of inlet chambers and / or outlet chambers. Furthermore, the parameters (e.g., pressure, temperature, flow rate, etc.) of the cooling gas in the intake chamber (e.g., intake chamber 1, intake chamber 2, ..., intake chamber N) and / or the exhaust chamber (e.g., exhaust chamber 1, exhaust chamber 2, ..., exhaust chamber N) may be different or the same.

[0108] In some embodiments, one of the plurality of air inlet chambers may be connected to one of the cooling chambers 805. A cooling chamber 805 may be configured with a detector module (e.g., detector module 1, detector module 2, ..., detector module N). A detector module may include one or more detector rings. For example, detector module 805-1 may include k detector rings. As another example, detector module 805-2 may include m detector rings. As yet another example, detector module 805-N may include j detector rings. One of the plurality of air outlet chambers may be connected to one of the cooling chambers 805. Cooling gas provided by the cooler 810 can flow through the plurality of air inlet chambers to the plurality of cooling chambers 805 respectively. The quantities k, m, j, and N are integers greater than 0. The quantities k, m, j, and N may be the same or different.

[0109] In some embodiments, the flow rate of cooling gas supplied to the detector module can be controlled based on the rate of heat generation in the detector module. For example, if the temperature of the detector module increases at a rate exceeding a threshold, or at a rate exceeding a threshold, the flow rate of cooling gas supplied to the detector module can be increased. In some embodiments, the supply of cooling gas to multiple heat-generating components can be controlled individually. For example, the flow rates of cooling gas supplied to multiple detector modules can be different. The flow rate of cooling gas supplied to the heat-generating components can be changed by altering the opening of one or more valves (not shown) configured in the cooling chamber 805 and / or the inlet chamber.

[0110] It should be noted that the above regarding Figure 8A and 8BThe description is for illustrative purposes only and is not intended to limit the scope of the invention. Various variations or modifications can be made by those skilled in the art under the guidance of this invention. For example, the cooling assembly 116 may further include one or more components, such as one or more thermal insulation layers. As another example, the cooling assembly 116 may further include one or more cavities configured as cooling gas passages. As yet another example, detector module 1 and detector module 2 may be configured with a single cooling cavity, also referred to as cooling cavity 805-1 and cooling cavity 805-2, which may be integrated into a single cooling cavity. As yet another example, cooling cavity 805-1 and cooling cavity 805-2 may be interconnected. In some embodiments, cooling cavity 805-1 and cooling cavity 805-2 may be configured with an inlet chamber and / or an outlet chamber. However, these variations and modifications do not depart from the scope of the invention. For further description of the air-cooling components, please refer to references such as U.S. Patent Application No. 15 / 175,785, filed June 7, 2016, entitled “SYSTEM AND METHOD FORCOOLING COMPONETS IN AN IMAGING SYSTEM”, the contents of which are incorporated herein by reference.

[0111] Figure 9B This is a schematic diagram of a water-cooled assembly and multiple detector modules according to some embodiments of the present invention. The cooling assembly 116 can use a cooling medium such as gas, liquid, or a combination of several of these. The description of the cooling assembly 116 herein is for illustrative purposes and does not limit the scope of the invention. Figure 9A and Figure 9B The cooling component 116 can use a liquid cooling medium, or simply coolant. For example... Figure 9A As shown, the cooling assembly 116 may include a coolant 902, a valve 904, a pump 906, an inlet / outlet 908, a heat exchanger 910, a liquid distributor 912, and a temperature controller 914. In some embodiments, the pump 906, the heat exchanger 910, and / or the liquid distributor 912 may be interconnected via one or more pipes. In some embodiments, the temperature controller 914 may be connected to the valve 904, the pump 906, the inlet / outlet 908, the heat exchanger 910, and / or the liquid distributor 912 via a wireless and / or wired connection.

[0112] Coolant 902 can cool heat-generating components (e.g., detector assembly 112 of scanner 110, electronic module 115, etc.) by absorbing and / or transferring heat generated by heat-generating components. In some embodiments, coolant 902 may include water, oil, polyalkylene glycol (PAG), cutting fluid, nanofluid (e.g., copper oxide, alumina, titanium, carbon nanotubes, etc.), liquefied gas (e.g., carbon dioxide), Freon, etc.

[0113] Valve 904 can control the open / closed state of the pipe and / or the flow rate of the coolant. In some embodiments, valve 904 can control the flow rate and / or flow speed of coolant 902 from or to pump 906, heat exchanger 910 and / or liquid distributor 912.

[0114] Pump 906 can drive coolant to flow within a liquid cooling assembly. In some embodiments, pump 906 may include one or a combination of several of the following: positive displacement pump, pulse pump, velocity pump, gravity pump, pneumatic pump, valveless pump, centrifugal pump, etc. For example, a positive displacement pump may include a rotary lobe pump, screw pump, rotary gear pump, piston pump, diaphragm pump, helical pump, gear pump, hydraulic pump, vane pump, peristaltic pump, rope pump, flexible impeller pump, etc. In some embodiments, pump 906 can exchange fluid with heat exchanger 910 through inlet / outlet 908.

[0115] Inlet / outlet 908 may be connected to heat exchanger 910. In some embodiments, the liquid cooling assembly may include an inlet and an outlet. In some embodiments, pump 906, heat exchanger 910, and / or liquid distributor 912 may share inlet / outlet 908. For example, coolant 902 may flow into or out of pump 906, heat exchanger 910, and / or liquid distributor 912 through inlet / outlet 908. In some embodiments, pump 906, heat exchanger 910, and / or liquid distributor 912 may have their own inlet / outlet 908.

[0116] Heat exchanger 910 enables heat transfer between coolant 902 and refrigerant (also referred to as coolant). Refrigerant includes one or more of the following: Freon, azeotropic mixtures, hydrocarbon refrigerants, etc. For example, coolant 902 can absorb heat from heat-generating components (e.g., detector assembly 112 of scanner 110, electronic module 115, etc.) and can flow to heat exchanger 910 driven by pump 906. Coolant 902 used in heat exchanger 910 can transfer the heat absorbed from the heat-generating components to the refrigerant. In some embodiments, the refrigerant can be separated from coolant 902 by a solid wall to prevent mixing. In some embodiments, heat exchanger 910 can include one or more of the following: shell-and-tube heat exchanger, plate heat exchanger, plate-and-shell heat exchanger, insulated wheel heat exchanger, plate-fin heat exchanger, pillow plate heat exchanger, fluid heat exchanger, dynamic scraped plate heat exchanger, phase change heat exchanger, direct contact heat exchanger, microchannel heat exchanger, etc.

[0117] The liquid distributor 912 can distribute coolant 902 into different channels. These channels can transport the coolant 902 to target locations (e.g., around the detector assembly 112, electronic module 115, etc. of scanner 110). In some embodiments, the liquid distributor 912 can control the amount of coolant 902 distributed into a single channel. For example, if a portion of the detector assembly 112 is at a high temperature, the liquid distributor 912 can increase the flow rate of coolant 902 in the channel corresponding to that portion of the detector assembly 112. As another example, the liquid distributor 912 can distribute the coolant 902 evenly into the different channels. In some embodiments, the liquid distributor 910 can include various types, including, for example, single-pass, weir, pressure-type, spray, and porous tube types.

[0118] Temperature controller 914 can control the temperature of heat-generating components (e.g., detector assembly 112 of scanner 110, electronic module 115, etc.) by controlling one or more modules in the water cooling assembly (e.g., valve 904, pump 906, inlet / outlet 908, heat exchanger 910, and / or liquid distributor 912). For example, temperature controller 914 can control liquid distributor 910 to increase the flow rate of coolant 902 to the channel corresponding to detector assembly 112, thereby reducing the temperature of detector assembly 112. As another example, temperature controller 914 can control pump 906 to increase the pressure and / or flow rate of coolant 902, thereby reducing the temperature of heat-generating components. As yet another example, temperature controller 914 can control heat exchanger 910 to reduce the temperature of coolant 902, thereby reducing the temperature of heat-generating components. In some embodiments, temperature controller 914 may include one or more temperature sensors connected to a target location (e.g., detector assembly 112 of scanner 110, electronic module 115, etc.) to monitor the temperature at the target location.

[0119] Figure 9B This diagram illustrates an exemplary water-cooling assembly and multiple detector modules according to some embodiments of the present invention. Figure 9B As shown, the liquid distributor 912 can distribute coolant 902 into multiple pipes. These multiple pipes allow fluid to flow at different target locations around multiple detector modules (e.g., first detector module 921, second detector module 922, third detector module 923, fourth detector module 924, fifth detector module 925, sixth detector module 926, seventh detector module 927, eighth detector module 928, etc.). One of the multiple pipes can be connected to a detector module. In some embodiments, a pipe can be attached to one or more surfaces of a detector module, so that the coolant 902 flowing in the pipe can absorb heat from the detector module.

[0120] Figure 9C This is a schematic diagram of a water-cooling assembly and multiple detector modules according to some embodiments of the present invention. Figure 9C As shown, the water cooling assembly may include a water cooling device 916 and at least two water distributors (e.g., water distributor 918-1 and water distributor 918-2). The water cooling device 916 may include, for example... Figure 9A The pump, inlet / outlet, heat exchanger, and / or temperature controller 914 are described. The water distributor 918-1 can distribute a lower-temperature coolant (e.g., water) to multiple target areas around multiple detector modules according to a specific flow rate. A detector module may include one or more detector rings. In some embodiments, a detector module may refer to... Figure 6E A PET unit is shown. (As shown) Figure 9C As shown, water distributor 918-1 can distribute coolant (e.g., water) to the first PET unit 920-1, the second PET unit 920-2, the third PET unit 920-3, the fourth PET unit 920-4, the fifth PET unit 920-5, the sixth PET unit 920-6, the seventh PET unit 920-7, the eighth PET unit 920-8, etc. It should be noted that the number of PET units mentioned here is for illustrative purposes only and is not intended to limit the scope of the invention. Water distributor 918-2 can aggregate the coolant that has absorbed heat from the target area surrounding the multiple detector modules and transfer the heated liquid to the water cooling device 916.

[0121] In some embodiments, the water cooling device 916 can cool a specific amount of coolant to a lower temperature over a period of time via a heat exchanger (e.g., heat exchanger 910). A pump can drive the coolant through an inlet to a water distributor 918-1. The water distributor 918-1 can distribute the specific amount of coolant at the lower temperature into multiple portions and distribute the multiple portions of coolant to multiple target areas around multiple detector modules. The lower-temperature coolant can absorb heat generated by other heat-generating components (e.g., electronic components 115) around the detector modules or target areas. The used coolant can reach a higher temperature after absorbing heat. The used coolant at the higher temperature can then be transferred to a water distributor 918-2 and mixed there. The mixed used coolant can be transferred back to the heat exchanger in the water cooling device 916. Then, in the heat exchanger, the used coolant at the higher temperature can be cooled to provide a lower-temperature coolant for reuse. The water cooling assembly can cycle through the above operations to cool the scanner 110. For a more detailed description of the water cooling assembly in scanner 110, please refer to references such as Chinese Patent Application No. 201710075120, filed on February 13, 2017, entitled "PET Imaging Equipment and PET-CT Imaging Equipment", the contents of which are incorporated herein by reference.

[0122] It should be noted that the above regarding Figures 9A-9C The description is for illustrative purposes only and is not intended to limit the scope of the invention. Many variations or modifications can be made by those skilled in the art within the scope of this invention. For example, valve 904 and / or inlet / outlet 908 can be integrated into other modules in the cooling assembly 116, such as pump 906, heat exchanger 910, and / or liquid distributor 912. As another example, the cooling assembly 116 can include one or more conduits for transferring coolant 902 to one or more target locations. As yet another example, one or more detector modules (e.g., PET units) can be connected to the same conduit. As yet another example, the number of PET units can be any integer greater than 0. However, these variations and modifications do not depart from the scope of the invention.

[0123] Figure 10 This is a schematic diagram of a processing engine 140 according to some embodiments of the present invention. The processing engine 140 may include an acquisition module 1002, a control module 1004, a processing module 1006, and a storage module 1008. At least a portion of the processing engine 140 may be implemented on a computing device.

[0124] Acquisition module 1002 can acquire data or signals. In some embodiments, acquisition module 1002 can acquire data from scanner 110, memory 150, terminal 130, and / or external data source (not shown). In some embodiments, the data may include one or a combination of image data (e.g., projection data), instructions, etc. For example, image data may be generated based on radiation (e.g., gamma rays) emitted from an object being detected and placed in detection area 113. In some embodiments, image data may include information about the energy of the radiation (e.g., gamma rays), information related to the interaction position of the radiation (e.g., gamma rays) in detector assembly 112, and / or information related to the interaction time of the radiation (e.g., gamma rays) in detector assembly 112. Instructions may be executed by the processor of processing engine 140 to perform the methods described in this invention. In some embodiments, acquired data may be transferred to storage module 1008 for storage.

[0125] The control module 1004 can generate one or more control parameters to control one or more of the following components: acquisition module 1002, processing module 1006, storage module 1008, scanning bed 114, detector assembly 112, cooling assembly 116, and electronics module 115. For example, the control module 1004 can control whether the acquisition module 1002 acquires image data. As another example, the control module 1004 can control whether the electronics module 115 acquires electrical signals, the timing of acquiring electrical signals, or the frequency of acquiring electrical signals. As yet another example, the control module 1004 can control the operation of the scanner 110 (e.g., detector assembly 112, scanning bed 114, electronics module 115, cooling assembly 116, etc.). Furthermore, the control module 1004 can control the processing module 1006 to select different algorithms to process the data acquired by the acquisition module 1002 or the electrical signals acquired by the electronics module 115. In some embodiments, the control module 1004 may receive real-time instructions or predetermined instructions provided by a user (e.g., a doctor, technician, etc.) to control one or more operations of the scanner 110, the acquisition module 1002, and / or the processing module 1006. For example, the control module 1004 may adjust the acquisition module 1002 and / or the processing module 1006 to generate an image of the object being examined according to real-time or predetermined instructions. In some embodiments, the control module 1004 may communicate with other modules in the PET imaging system 100 for information and / or data exchange.

[0126] Processing module 1006 can process information provided by multiple modules of processing engine 140. Processing module 1006 can process data acquired by acquisition module 1002, signals acquired by electronic module 115, data retrieved from storage module 1008, etc. In some embodiments, processing module 1006 can reconstruct one or more images based on reconstruction techniques, data, or signals, generate a report including one or more images and / or other relevant information, and / or perform any other functions for image reconstruction. Reconstruction techniques may include one or more combinations of iterative reconstruction algorithms (e.g., maximum likelihood expectation maximization algorithm, ordered subset expectation maximization algorithm), filtered back projection algorithms, 3D reconstruction algorithms, analysis, etc. In some embodiments, processing module 1006 can correct the data or reconstructed image based on one or more correction techniques. Correction techniques may include one or more combinations of random correction, scattering correction, attenuation correction, dead time correction, normalization correction, etc. In some embodiments, processing module 1006 can perform one or more corrections in image reconstruction.

[0127] Storage module 1008 may store one or more of the following: data or signals, control parameters, processed data or signals, etc. In some embodiments, storage module 1008 may store one or more programs and / or instructions executable by the processor of processing engine 140 to perform the exemplary methods described in this invention. For example, storage module 1008 may store programs and / or instructions executable by the processor of processing engine 140 to acquire data or signals, reconstruct images based on the data or signals, and / or display any intermediate results or composite images.

[0128] In some embodiments, Figure 10 One or more modules shown can be used as follows Figure 1 This is implemented in at least a portion of the illustrated PET imaging system 100. For example, the acquisition module 1002, control module 1004, storage module 1008, and / or processing module 1006 may be integrated into a single console (not shown). Through this console, a user can set parameters for scanning the object being detected, acquire data or signals, etc. In some embodiments, the console may be implemented via a processing engine 140 and / or an external device (not shown).

[0129] Figure 11 This is an exemplary flowchart of a PET imaging process 1100 according to some embodiments of the present invention. In some embodiments, Figure 11 The process 1100 shown can be used for one or more operations in PET imaging. Figure 1 This is implemented in the PET imaging system 100 shown. For example, Figure 11The illustrated process 1100 can be stored in memory 150 as instructions and invoked and / or executed by processing engine 140 (e.g., the processor of a computing device). For example, a portion of process 1100 can be implemented in scanner 110.

[0130] In step 1101, the scan can be initialized. In some embodiments, operation 1101 can be performed by control module 1004. In some embodiments, initialization can be performed based on one or more of the following: a scan protocol, user input, default settings of imaging system 100, etc. The scan protocol may include one or more of the following: the scan area of ​​the target, the dose of the tracer isotope, the uptake cycle of the tracer isotope, etc.

[0131] In some embodiments, detector assembly 112 may be initialized in 1101. In some embodiments, scanner 110 may have a large axial field of view (AFOV) (e.g., between 0.75 m and 2 m), and detector assembly 112 may have an axial length greater than or equal to the axial field of view (AFOV). Since the number of detectors in scanner 110 with a large axial field of view (AFOV) can be greater than the number of detectors in scanners with a normal axial field of view (AFOV) (e.g., 0.16 m to 0.3 m, 0.16 m to 0.5 m, etc.), detector alignment and functionality are important for achieving excellent performance. In some embodiments, validity testing of detector assembly 112 may be performed in 1101. For example, the axial alignment of the detectors may be tested. As another example, the functionality of the detectors within the axial field of view (AFOV) range may be tested. A large axial field of view (AFOV) allows for the detection of more radiation and increases the complexity of identifying crystals with radiation interactions. Having more detectors enhances spatial distortion in crystal identification. In some embodiments, the position of the detector (or crystal) can be calibrated based on a position calibration algorithm, such as a position calibration algorithm based on a crystal position lookup table. The crystal position lookup table maps inaccurate interactive positions to precise interactive crystal positions. The crystal position lookup table can be generated based on one or more algorithms, including, for example, principal component analysis (PCA) based algorithms, hierarchical fusion algorithms, region segmentation based algorithms, and combinations thereof. In some embodiments, the crystal position lookup table can be generated or obtained in 1101. For example, the crystal position lookup table can be obtained from memory 150, storage module 1008, or an external data source (not shown). Further description of the crystal position lookup table can be found in, for example, U.S. Patent Application No. 20160321808A1, published November 3, 2016, entitled “METHOD AND SYSTEM FORCRYSTAL IDENTIFICATION,” the contents of which are incorporated herein by reference.

[0132] In some embodiments, detector assembly 112 can be initialized to "activate" some detectors while deactivating the remaining detectors. For example, if it is necessary to scan the head of a target, some detectors within a certain axial range (e.g., 20 cm) can be "activated" to detect radiation emitted from the head, while the remaining detectors may not detect radiation, even if the radiation may reach the remaining detectors. As another example, if it is necessary to scan the entire body of a target, multiple detectors surrounding the body (e.g., detectors along a 1.8-meter axial field of view (AFOV) length) can be selected to detect signals. In some embodiments, different detectors of detector assembly 112 can be selected to detect signals at different times. Detector selection and scan start time can be initialized in 1101 based on a scanning protocol. For example, a first portion of detectors can be "activated" to scan the head at time T1, while a second portion of detectors can be "activated" to scan the feet at time T2.

[0133] In some embodiments, the cooling assembly 116 may be initialized at 1101. In some embodiments, the flow rate (or flow rate) of cooling air or coolant may be initialized. In some embodiments, which air chamber (or which valve) needs to be opened may be initialized. Since the primary function of the cooling assembly 116 may be to cool the heat-generating detector, the cooling assembly 116 may be initialized based on the initialization of the detector assembly 112. For example, if it is necessary to "activate" the detector of the first part to make it work at time T1, the air chamber (or valve) that introduces cooling air (or coolant) to the surface of the detector of the first part may be opened at time T1 or earlier, or the flow rate (or flow rate) of cooling air or coolant through the detector of the first part may be increased at time T1.

[0134] In some embodiments, one or more parameters can be initialized in 1101. Parameters may include scan parameters, reconstruction parameters, etc. Scan parameters may include scan start time, scan duration, signal acquisition frequency, coincidence time window, offset (e.g., ... Figure 7C (as shown), energy threshold, etc. In some embodiments, the coincidence time window may be related to the offset. The larger the offset, the larger the coincidence time window. In some embodiments, a variable coincidence time window can be set based on the offset. For example, if the offset is 0, a relatively small coincidence time window can be set, while if the offset is greater than 0, a relatively large coincidence time window can be set. Reconstruction parameters may include one or more of the following: image resolution, filters, one or more parameters used for reconstruction techniques (e.g., the number of iterations in iterative reconstruction, coefficient thresholds, etc.). In some embodiments, parameters may be initialized based on one or more of the following: user input, system defaults, etc.

[0135] In some embodiments, the desired position of the scan bed 114 can be initialized in 1101. The desired position can be located within the scanning field of view (e.g., lateral and axial fields of view) of the detection area 113. In some embodiments, the desired position of the scan bed 114 can be initialized based on one or more of the following: scanning protocol, user input, system defaults, etc. For example, the desired position of the scan bed 114 can be determined based on the scanning area of ​​the object being detected. In some embodiments, the desired position of the scan bed 114 can be associated with an "active" detector. For example, the desired position of the scan bed 114 can be located within a dedicated area surrounded by the "active" detector. In some embodiments, the object being detected placed on the scan bed 114 can be moved to the desired position. The scan bed 114 can move in axial, vertical, and horizontal directions perpendicular to the axial and vertical positions.

[0136] In 1103, an electrical signal generated by scanning can be acquired. In some embodiments, operation 1103 can be performed by an electronics module 115. A detector assembly 112 can be used to receive multiple radiation rays. The radiation rays can be gamma rays emitted from a target object placed in a detection region 113. Prior to scanning, a radioactive tracer isotope can be injected into the target object. One or more atoms of the tracer isotope can chemically bind to biologically active molecules in the target object. The active molecules can become concentrated in one or more tissues of interest within the target object. The tracer isotope can undergo positron emission decay and emit one or more positrons. The positrons can travel a short distance (e.g., about 1 mm) within the tissue of interest, lose kinetic energy, and interact with electrons in the target object. The positrons and electrons can annihilate and produce a pair of annihilation photons. The annihilation photons (or radiation rays) can move in generally opposite directions. Multiple radiation rays can reach the detector assembly 112 and be received by a scintillator (e.g., scintillator array 410) in the detector assembly 112. The scintillator can then absorb the energy of photons from radiation (e.g., gamma rays) and convert the absorbed energy into visible light. Multiple electrical signals can then be generated by a photoelectric sensor coupled to the scintillator based on the absorbed radiation.

[0137] In some embodiments, the interaction location and / or interaction time of the received radiation can be determined by electronic module 115. The interaction location can be used to identify which scintillator in detector assembly 112 has a radiation interaction with the received radiation, and / or the interaction depth of the received radiation in the identified scintillator. The interaction location can be determined based on the energy of the electrical signal and one or more algorithms, including, for example, centroid algorithm, Anger logic algorithm, maximum likelihood estimation algorithm, or localization algorithm based on an artificial neural network model, or a combination thereof. In some embodiments, the interaction time can be determined based on the energy of the electrical signal and / or the acquisition time. In some embodiments, the interaction time can be determined based on a lower limit detection circuit (or constant coefficient discriminator circuit) and a time-to-digital converter. In some embodiments, the interaction time can be corrected based on the interaction depth and time correction techniques. Time correction techniques can include dead time correction, time roaming correction, etc.

[0138] In 1105, image data can be obtained based on the electrical signals acquired in 1103. In some embodiments, operation 1105 can be performed by electronic module 115. In some embodiments, the image data can include data about one or more response lines (LORs). In some embodiments, one or more coincidence events can be determined based on the interaction positions and interaction times of multiple received radiation lines. If two radiation lines are received and interact with two scintillators within a certain time window (e.g., 1 nanosecond, 2 nanosecond, 5 nanosecond, 10 nanosecond, 20 nanosecond, etc.), the two radiation lines can be determined to originate from the same annihilation and designated as coincidence events. In some embodiments, coincidence events can be determined by the coincidence circuit of electronic module 115. Coincidence events can be assigned to the response lines of two related scintillators that detect coincidence events. Coincidence events assigned to the same response line (LOR) can be projected, and image data can be generated. In some embodiments, the image data can be stored as a sine wave in memory 150, storage module 1008, external data source, etc. In some embodiments, image data can be acquired from external data sources such as memory 150 and storage module 1008 by acquisition module 1002.

[0139] In 1107, an image can be generated based on the image data obtained in 1105. In some embodiments, operation 1107 can be performed by processing module 1006. In some embodiments, image data can be processed to generate an image. Image data can be processed based on one or more algorithms, including, for example, noise reduction algorithms, reconstruction algorithms, correction algorithms, etc. In some embodiments, the reconstruction algorithm can include one or more of iterative reconstruction algorithms (e.g., maximum likelihood expectation maximization algorithm, ordered subset expectation maximization algorithm), filtered back projection algorithm, 3D reconstruction algorithm, analysis, etc. In some embodiments, the correction algorithm can include one or more of random correction, scattering correction, attenuation correction, dead time correction, normalization correction, etc. The reconstructed image can show the tracer distribution within the detected object. In some embodiments, a whole-body image can be generated based on electrical signals generated by a large axial field of view (AFOV) scanner (e.g., scanner 110). In some embodiments, mechanical installation errors (e.g., Figure 6C The deviation between the centers of the two imaging units described.

[0140] In step 1109, the image generated in step 1107 can be output. In some embodiments, operation 1109 can be performed by control module 1004. In some embodiments, the image can be output to storage module 1008, memory 150, external data source, etc. for storage. In some embodiments, the image can be output to terminal 130 for display.

[0141] It should be noted that the above description of process 1100 is for illustrative purposes only and is not intended to limit the scope of the invention. Those skilled in the art will be able to make various variations and modifications to process 1100 under the guidance of this invention. However, these variations and modifications will not depart from the scope of the invention. For example, an image segmentation operation can be added after operation 1107.

[0142] The above outlines different aspects of imaging systems and / or methods for implementing other steps through programs. The program portion of the technology can be considered a "product" or "artifact" existing in the form of executable code and / or related data, and is engaged in or implemented through a computer-readable medium. Tangible, permanent storage media include memory or storage used by any computer, processor, or similar device or related module. Examples include various semiconductor memories, magnetic tape drives, disk drives, or any similar device capable of providing storage functionality for software at any time.

[0143] All software, or parts thereof, may sometimes communicate via networks, such as the Internet or other communication networks. Such communication enables the loading of software from one computer device or processor to another. For example, loading software from a management server or host computer of an on-demand service system to a hardware platform of a computer environment, or another computer environment that implements the system, or a system with similar functionality related to the information required to provide on-demand services. Therefore, another medium capable of transmitting software elements can also be used as a physical connection between local devices, such as light waves, radio waves, electromagnetic waves, etc., propagated through cables, fiber optic cables, or air. Physical media used for carrier waves, such as cables, wireless connections, or fiber optic cables, can also be considered as media carrying software. In this context, unless limited to tangible "storage" media, the term "readable medium" for a computer or machine refers to the medium involved in the execution of any instructions by the processor.

[0144] Therefore, a computer-readable medium can take many forms, including but not limited to tangible storage media, carrier media, or physical transmission media. Stable storage media include optical discs or hard disks, and other storage systems used in computers or similar devices that enable the system components described in the figure. Unstable storage media include dynamic memory, such as the main memory of a computer platform. Tangible transmission media include coaxial cables, copper cables, and optical fibers, including lines that form buses within a computer system. Carrier transmission media can transmit electrical signals, electromagnetic signals, acoustic signals, or optical signals, which can be generated by radio frequency or infrared data communication methods. Common computer-readable media include hard disks, floppy disks, magnetic tapes, and any other magnetic media; CD-ROMs, DVDs, DVD-ROMs, and any other optical media; punched cards and any other physical storage media containing punch patterns; RAM, PROMs, EPROMs, FLASH-EPROMs, and any other memory chips or magnetic tapes; carrier waves for transmitting data or instructions, cables, or connection devices for transmitting carrier waves; and any other program code and / or data that can be read by a computer. These forms of computer-readable media can occur in many ways during the process of a processor executing instructions and delivering one or more results.

[0145] The computer program code required for the operation of each part of this 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, Visual Basic, Fortran 2003, Perl, COBOL 2002, PHP, ABAP, dynamic programming languages ​​such as Python, Ruby, and Groovy, or other programming languages. This program code can run entirely on the user's computer, or as a standalone software package on the user's computer, or partially on the user's computer and partially 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, such as a local area network (LAN) or 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).

[0146] Those skilled in the art will understand that the content disclosed herein can be varied and modified in many ways. For example, the different system components described above are implemented using hardware devices, but they may also be implemented using only software solutions. For example, installing the system on an existing server. Furthermore, the provision of the location information disclosed herein may be achieved through firmware, a combination of firmware and software, a combination of firmware and hardware, or a combination of hardware / firmware / software.

[0147] The foregoing describes this application and / or some other examples. Based on the foregoing, this application can also be modified in various ways. The subject matter disclosed in this application can be implemented in different forms and examples, and this application can be applied to a wide range of applications. All applications, modifications, and alterations claimed in the following claims are within the scope of this application.

[0148] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0149] Furthermore, unless expressly stated in the claims, the order of processing elements and sequences, the use of numbers and letters, or other names described in this application are not intended to limit the order of the processes and methods of this application. Although the foregoing disclosure has discussed some currently considered useful embodiments of the invention through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments; rather, the claims are intended to cover all modifications and equivalent combinations that conform to the substance and scope of the embodiments of this application. For example, while the system components described above can be implemented using hardware devices, they can also be implemented solely through software solutions, such as installing the described system on existing servers or mobile devices.

[0150] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0151] In some embodiments, numbers describing attributes and quantities are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0152] For each patent, patent application, patent application publication, and other material such as articles, books, specifications, publications, documents, and objects referenced in this application, the entire contents of that patent are incorporated herein by reference. This excludes historical application documents that are inconsistent with or conflict with the content of this application, as well as documents that limit the broadest scope of the claims in this application (currently or subsequently appended to this application). It should be noted that if there are any inconsistencies or conflicts between the descriptions, definitions, and / or terminology used in the supplementary materials of this application and the content of this application, the descriptions, definitions, and / or terminology used in this application shall prevail.

[0153] 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 modifications may also fall within the scope of this application. Therefore, alternative configurations of the embodiments of this application are considered as examples and not limitations, and are regarded as consistent with the teachings of this application. Accordingly, the embodiments of this application are not limited to the embodiments explicitly described and illustrated in this application.

Claims

1. An imaging system, characterized in that, The imaging system includes: A support component, the support component including a detection area for accommodating the object to be detected; A detector assembly, disposed around the detection area, is used to detect radiation emitted by a detected object within the detection area. The detector assembly includes multiple detection rings, each ring comprising a scintillator array and multiple photoelectric sensors. The multiple detection rings are mounted on the support assembly along its axial direction to form an axial field of view with a length of not less than 0.75 meters. The support assembly includes N support modules, and two adjacent support modules are connected to each other by at least one of welding, riveting, and bolting. The detector assembly includes N detector modules, each detector module including a portion of the plurality of detector rings, where N is an integer greater than 1, and two adjacent detector modules have a first spacing in the axial direction, the first spacing being less than 20 mm; The N detector modules and the N support modules are configured into N imaging units, each imaging unit including at least one detector module from the N detector modules and at least one support module from the N support modules; and A scanning bed is used to support the object being inspected; A processing engine is configured to initialize the detector assembly to activate a portion of the detectors along the axial direction, deactivating the remaining detectors, and to initialize the desired position of the scanning bed, moving the scanning bed so that the object to be detected placed on the scanning bed is moved to the desired position, wherein... The required position is located within the scanning field of view of the detection area. The required location is associated with the activated portion of the detector.

2. The imaging system according to claim 1, characterized in that, The support assembly includes N support modules, wherein the N detector modules and the N support modules are configured as N imaging units, and each detector module is assembled to the corresponding support module to form an imaging unit; At least one of the N imaging units can be assembled along the axial direction and can be separated.

3. The imaging system according to claim 2, characterized in that, The processing engine is used to activate M detector modules in N imaging units, where M is a positive integer less than N.

4. The imaging system according to claim 1, characterized in that, The processing engine is also used to select different detectors in the detector assembly to detect signals at different times.

5. The imaging system according to claim 1, characterized in that, The processing engine is also used to initialize detector selection and start scan time based on the scanning protocol.

6. The imaging system according to claim 1, characterized in that, The imaging system also includes a cooling component, and the processing engine is further configured to initialize the cooling component based on the initialization of the detector component to cool the activated portion of the detector.

7. The imaging system according to claim 6, characterized in that, The processing engine is also used to initialize the flow rate of the cooling air in the cooling assembly; or Based on the activation of the first part of the detector, the processing engine is also used to increase the flow rate of cooling air passing through the first part of the detector during the first time.

8. The imaging system according to claim 6, characterized in that, Based on the activation of the first portion of the detector operating at a first time, the processing engine is also configured to activate the cooling assembly at or before the first time to introduce cooling air into the air cavity on the surface of the first portion of the detector.

9. The imaging system according to claim 6, characterized in that, The processing engine is also used to initialize the coolant flow rate of the cooling component; or Based on the activation of the first portion of the detector operating at a first moment, the processing engine is also used to increase the flow rate of coolant passing through the first portion of the detector at that first moment.

10. The imaging system according to claim 6, characterized in that, Based on the activation of the first portion of the detector operating at a first time, the processing engine is also used to open the cooling assembly at or before the first time to introduce coolant into the valves on the surface of the first portion of the detector.

Images