Imaging methods corresponding to detector components and imaging systems

Abstract

Embodiments of this specification provide a detector assembly and an imaging method corresponding to an imaging system. The detector assembly includes at least two first crystal modules, at least one second crystal module, and at least one non-detection module. The at least two first crystal modules can be configured to detect a first portion of photons and generate a first scintillation. Each of the at least two first crystal modules has a first detection capability. The at least one second crystal module can be configured to detect a second portion of the photons and generate a second scintillation. Each of the at least one second crystal module has a second detection capability. The second detection capability is less than the first detection capability. The at least two first crystal modules can be separated by at least one of the at least one second crystal module and the at least one non-detection module.

Description

Technical Field

[0001] The embodiments of this specification relate to the field of radiation detection, and more particularly to a detector assembly and an imaging method corresponding to the imaging system. Background Art

[0002] Detector assemblies in imaging devices, such as positron emission tomography (PET) devices, typically include scintillation crystals and sensors connected thereto. The scintillation crystals can be used to detect photons emitted by a subject (e.g., a patient) and produce scintillation, and the sensors can be used to detect this scintillation. Imaging data can be generated based on the detected scintillation. Detector assemblies in imaging devices typically contain a large number of scintillation crystals, which are expensive. Therefore, there is an urgent need to design lower-cost detector assemblies. Summary of the Invention

[0003] In one aspect, the present disclosure provides a detector assembly. The detector assembly includes at least two first crystal modules, at least one second crystal module, and at least one non-detection module. The at least two first crystal modules can be configured to detect a first portion of photons and generate a first scintillation. Each of the at least two first crystal modules has a first detection capability. The at least one second crystal module can be configured to detect a second portion of the photons and generate a second scintillation. Each of the at least one second crystal module has a second detection capability, wherein the second detection capability is less than the first detection capability. The at least two first crystal modules can be separated by at least one of the at least one second crystal module and the at least one non-detection module.

[0004] In some embodiments, each of the at least two first crystal modules or the at least one second crystal module may include at least two crystal units.

[0005] In some embodiments, each of the at least two crystal units may be composed of one or a combination of cerium-doped yttrium lutetium silicate, cerium-doped lutetium silicate, bismuth germanate, sodium iodide, cesium iodide, gadolinium silicate, calcium fluoride, cesium fluoride, and barium fluoride.

[0006] In some embodiments, the detector assembly may further include a sensor. The sensor may be configured to detect the first scintillation and the second scintillation. The sensor may include: at least one first sensing module configured to detect a first portion of the first scintillation and the second scintillation; and at least one second sensing module configured to detect a second portion of the first scintillation and the second scintillation. Each of the at least one first sensing module has a third detection capability. Each of the at least one second sensing module has a fourth detection capability. The fourth detection capability is less than the third detection capability.

[0007] In some embodiments, the sensor may further include at least one second non-detection module. The at least one first sensing module may be separated from at least one of the at least one second sensing module and the at least one second non-detection module.

[0008] In some embodiments, each of the at least one first sensing module or the at least one second sensing module includes at least two sensing units.

[0009] In some embodiments, each of the at least two sensing units may be composed of a silicon photomultiplier, a photomultiplier tube, or a combination thereof.

[0010] In some embodiments, each of the at least one non-detection module or the at least one second non-detection module can be composed of one of glass, air, or a combination thereof.

[0011] In some embodiments, the at least two first crystal modules may include at least two first crystal units. The at least one second crystal module may include at least two second crystal units. The at least one non-detection module may include at least two non-detection units. The number of the at least two first crystal units accounts for 30% to 99% of the total number of the at least two first crystal units, the at least two second crystal units, and the at least two non-detection units.

[0012] Another aspect of the present specification provides an imaging method corresponding to an imaging system. The imaging system may include a detector assembly. The detector assembly may include: at least two first crystal modules configured to detect a first portion of photons and generate a first scintillation, each of the at least two first crystal modules having a first detection capability; at least one second crystal module configured to detect a second portion of the photons and generate a second scintillation, and configured to randomly space the at least two first crystal modules, each of the at least one second crystal module having a second detection capability, and the second detection capability being less than the first detection capability; and a sensor connected to the at least two first crystal modules and / or the at least one second crystal module, the sensor configured to detect the first scintillation and / or the second scintillation. The method may include: generating first imaging data based on the detected first scintillation; generating second imaging data based on the detected second scintillation; correcting the second imaging data based on the first imaging data; and generating an image based on at least a portion of the first imaging data and the corrected second imaging data.

[0013] The beneficial effects that may be brought about by the embodiments of this specification include but are not limited to: (1) using a second crystal module and / or a non-detection module made of cheaper materials to replace part of the first crystal module in the detector module can reduce the construction cost of the detector assembly compared to using only the first crystal module to construct the detector module. At the same time, by controlling the proportion of the first crystal module, the reconstructed image can be guaranteed to have a relatively high quality; (2) compared to using only the first crystal module to construct the detector module, when the same number of first crystal modules is used to construct a sparse detector module, the detection area corresponding to the detector module is larger, which can shorten the imaging time; (3) using a second sensor module and / or a second non-detection module made of cheaper materials to replace part of the first sensor module in the sensor can reduce the construction cost of the detector assembly compared to using only the first sensor module to construct the sensor; (4) correcting the imaging data corresponding to the second crystal module based on the first imaging data corresponding to the first crystal module can improve the quality of the reconstructed image. It should be noted that different embodiments may have different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other possible beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0015] Figure 1 is a schematic diagram of an exemplary imaging system according to some embodiments of the present specification;

[0016] Figure 2 is a schematic diagram of the arrangement of some modules in an exemplary detector assembly according to some embodiments of this specification;

[0017] Figure 3 is a schematic diagram of the arrangement of some modules in an exemplary detector assembly according to some embodiments of this specification;

[0018] Figure 4 is a schematic diagram of a lookup table corresponding to some modules in an exemplary detector assembly according to some embodiments of this specification;

[0019] Figure 5 is a block diagram of an exemplary imaging system according to some embodiments of the present specification;

[0020] Figure 6 is a flowchart of an imaging method corresponding to an exemplary imaging system according to some embodiments of this specification. DETAILED DESCRIPTION

[0021] To more clearly illustrate the technical solutions of the embodiments of this specification, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this specification. Those skilled in the art can apply this specification to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0022] It should be understood that the terms "system," "device," "unit," and / or "module" used in this specification are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0023] As used in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not refer to the singular but also include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0024] Flowcharts are used throughout this specification to illustrate the operations performed by systems according to embodiments of this specification. It should be understood that preceding or following operations do not necessarily need to be performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0025] Figure 1 is a schematic diagram of an exemplary imaging system according to some embodiments of the present specification.

[0026] like Figure 1 As shown, the imaging system 100 may include an imaging device 110, a processing device 120, a storage device 130, one or more terminals 140, and a network 150. The components of the imaging system 100 may be connected in various ways. For example, the imaging device 110 may be connected to the processing device 120 via the network 150. For another example, the imaging device 110 may be directly connected to the processing device 120, such as Figure 1 1 and 120. For another example, the storage device 130 can be connected to the processing device 120 directly or through the network 150. For another example, the terminal 140 can be connected directly (eg, Figure 1The terminal 140 and the processing device 120 are connected to each other via a dotted double-headed arrow (shown in FIG. 1 ) or are connected to the processing device 120 via a network 150 .

[0027] In some embodiments, the imaging device 110 may be configured to detect radiation and generate data related to the detected radiation. The radiation may include particle beams (e.g., neutrons, protons, muons, heavy ions), photon beams (e.g., X-rays, gamma rays, alpha rays, beta rays, ultraviolet rays, lasers), or the like, or any combination thereof. In some embodiments, the imaging device 110 may be configured to acquire imaging data related to at least a portion of an object. For example, the imaging device 110 may scan an object or portion thereof within its detection area and generate imaging data related to the object or portion thereof. The imaging data may include images, projection data, or the like, or any combination thereof. In some embodiments, the imaging data may include two-dimensional imaging data, three-dimensional imaging data, four-dimensional imaging data, or the like, or any combination thereof. The object may be a biological object or a non-biological object. For example, the object may include a patient, an animal, or an artificial object (e.g., a phantom). In another example, the object may include a patient portion, organ, or tissue, such as the head, neck, chest, heart, stomach, blood vessels, soft tissue, tumor, nodule, or the like, or any combination thereof. In some embodiments, the imaging device 110 may include a single-modality imaging device. For example, the imaging device 110 may include a positron emission tomography (PET) device, a single photon emission computed tomography (SPECT) device, a photon counting computed tomography (PCCT) device, etc. In some embodiments, the imaging device 110 may include a multimodal imaging device, such as a PET-CT device, a PET-MR device, a SPECT-CT device, a SPECT-MR device, a SPECT-PET device, etc., or any combination thereof.

[0028] In some embodiments, the processing device 120 can process data obtained from the imaging device 110, the terminal 140 or the storage device 130. The processing device 120 can be a central processing unit (CPU), a digital signal processor (DSP), a system on a chip (SoC), a microcontroller unit (MCU), etc. or any combination thereof. In some embodiments, the processing device 120 can be a single server or a server group. The server group can be centralized or distributed. In some embodiments, the processing device 120 can be local or remote. For example, the processing device 120 can access information and / or data stored in the imaging device 110, the terminal 140 and / or the storage device 130 via the network 150. For another example, the processing device 120 can be directly connected to the imaging device 110 (such as Figure 1 ), a dotted double-headed arrow connecting the imaging device 110 and the processing device 120 as shown in FIG), a terminal 140 (as shown in FIG Figure 11 and 120) and / or storage device 130 to access information and / or data. In some embodiments, processing device 120 may be implemented on a cloud platform. By way of example only, a cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an inter-cloud cloud, a multi-cloud, or any combination thereof.

[0029] The storage device 130 can store data and / or instructions. In some embodiments, the storage device 130 can store data obtained from the terminal 140 and / or the processing device 120. In some embodiments, the storage device 130 can store data and / or instructions used by the processing device 120 to perform the exemplary operations described in this specification. In some embodiments, the storage device 130 can include a mass storage device, a removable storage device, a volatile read-write memory, a read-only memory (ROM), or the like, or any combination thereof. Exemplary mass storage devices can include magnetic disks, optical disks, solid-state drives, or the like. Exemplary removable storage devices can include flash drives, floppy disks, optical disks, memory cards, compact disks, magnetic tapes, or the like. Exemplary volatile read-write memory can include random access memory (RAM). Exemplary RAM can include dynamic random access memory (DRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), static random access memory (SRAM), thyristor random access memory (T-RAM), and zero-capacitance random access memory (Z-RAM). Exemplary ROMs may include mask ROM (MROM), programmable ROM (PROM), erasable programmable ROM (PEROM), electrically erasable programmable ROM (eePROM), compact disc ROM (CD-ROM), and digital versatile disk ROM, among others. In some embodiments, storage device 130 may be implemented on a cloud platform. By way of example only, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an inter-cloud cloud, a multi-cloud, or any combination thereof.

[0030] In some embodiments, the storage device 130 can be connected to the network 150 to communicate with one or more components of the imaging system 100 (e.g., the terminal 140, the processing device 120). One or more components of the imaging system can access data or instructions stored in the storage device 130 through the network 150. In some embodiments, the storage device 130 can be directly connected to or communicate with one or more components of the imaging system 100 (e.g., the terminal 140, the processing device 120). In some embodiments, the storage device 130 can be part of the processing device 120.

[0031] Terminal 140 may include a mobile device 140-1, a tablet computer 140-2, a laptop computer 140-3, or the like, or any combination thereof. In some embodiments, mobile device 140-1 may include a smart home device, a wearable device, a smart mobile device, a virtual reality device, an augmented reality device, or the like, or any combination thereof. In some embodiments, smart home devices may include smart lighting devices, smart appliance control devices, smart monitoring devices, smart televisions, smart cameras, intercoms, or the like, or any combination thereof. In some embodiments, wearable devices may include bracelets, foot covers, glasses, helmets, watches, clothing, backpacks, or the like, or any combination thereof. In some embodiments, smart mobile devices may include smartphones, personal digital assistants (PDAs), gaming devices, navigation devices, point-of-sale (POS), or the like, or any combination thereof. In some embodiments, virtual reality devices and / or augmented reality devices may include virtual reality helmets, virtual reality glasses, virtual reality goggles, augmented reality helmets, augmented reality glasses, augmented reality goggles, or the like, or any combination thereof. In some embodiments, terminal 140 may remotely operate imaging device 110. In some embodiments, terminal 140 may operate imaging device 110 via a wireless connection. In some embodiments, terminal 140 may receive information and / or instructions input by a user and transmit the received information and / or instructions to imaging device 110 or processing device 120 via network 150. In some embodiments, terminal 140 may receive data and / or information from processing device 120. In some embodiments, terminal 140 may be part of processing device 120. In some embodiments, terminal 140 may be omitted.

[0032] The network 150 can facilitate the exchange of information and / or data. In some embodiments, one or more components of the imaging system 100 (e.g., the imaging device 110, the terminal 140, the processing device 120, or the storage device 130) can send information and / or data to another component in the imaging system 100 via the network 150. In some embodiments, the network 150 can be any type of wired or wireless network, or a combination thereof. The network 150 can be and / or include a public network (e.g., the Internet), a private network (e.g., a local area network (LAN), a wide area network (WAN)), a wired network (e.g., Ethernet), a wireless network (e.g., an 802.11 network, a Wi-Fi network), a cellular network (e.g., a Long Term Evolution (LTE) network), a frame relay network, a virtual private network ("VPN"), a satellite network, a telephone network, a router, a hub, a switch, a server computer, and / or any combination thereof. By way of example only, the network 150 may include a cable network, a wired network, a fiber optic network, a telecommunications network, an intranet, the Internet, a local area network (LAN), a wide area network (WAN), a wireless local area network (WLAN), a metropolitan area network (MAN), a public switched telephone network (PSTN), a Bluetooth network, a ZigBee network, a near field communication (NFC) network, the like, or any combination thereof. In some embodiments, the network 150 may include one or more network access points. For example, the network 150 may include a wired or wireless network access point, such as a base station and / or an Internet exchange point, through which one or more components of the imaging system 100 may connect to the network 150 to exchange data and / or information.

[0033] In some embodiments, a radioactive tracer may be injected into a subject (e.g., a patient), and then imaging data may be acquired by scanning the subject using an imaging device 110 (e.g., a PET device). In some embodiments, the imaging device 110 may include a detector assembly. The detector assembly is configured to detect at least a portion of photons (e.g., gamma photons) emitted by the subject and / or generate an electronic signal (e.g., a scintillation pulse). The electronic signal may be further converted into a computer-readable signal (e.g., a digital signal) to generate imaging data. During the scanning process, the radioactive tracer in the subject decays and emits positrons. The positrons may annihilate with surrounding electrons in the subject, generating photon pairs. Each pair of photons travels in opposite directions. The detector assembly may be configured to detect at least a portion of the photon pairs. When a pair of photons is detected within a coincidence time window, a coincidence event may be considered to have occurred. The line of response (LOR) corresponding to the coincidence event may be a line connecting two components of the detection assembly (e.g., two crystal modules or two crystal units, as described below) that detected the pair of photons. The line of response may be used to indicate the emission path of the pair of photons. In some embodiments, the imaging data may include photon data (e.g., position, time, and number) detected by different parts of the detector assembly (e.g., the crystal module and crystal unit described below), scintillation data (e.g., position, time, and number), coincidence event data (e.g., position, time, and number), line of response (LOR) data (e.g., position, time, and number), etc., or any combination thereof. For more information about imaging data, see Figure 6 And its description, I will not go into details here.

[0034] In some embodiments of the present specification, the detector assembly may include a detector module. The detector module may be configured to detect photons and generate scintillation. The detector module may include at least two first crystal modules (e.g., Figure 2-Figure 3 ) and at least one spacing module (as shown in Figure 2-Figure 3 In some embodiments, at least one spacing module may be configured to randomly space the at least two first crystal modules. As used herein, "random" may mean that at least one spacing module or at least two first crystal modules are not arranged in a specific shape (such as an L shape, a T shape), nor are they arranged periodically. For example only, a portion of the at least two first crystal modules and at least one spacing module may be arranged in a random manner. Figure 2Any of the arrangements shown in al. In some embodiments, at least a portion of at least one spacing module may separate at least two first crystal modules according to a certain rule (such as a specific shape, a periodic arrangement). Compared to the at least two first crystal modules, at least one spacing module may be constructed of a lower-cost material. Therefore, compared to a detector assembly consisting only of first crystal modules, the cost of the detector assembly can be reduced by introducing a spacing module to replace part of the first crystal modules. In some embodiments of the present specification, a detector module comprising a spacing module may also be referred to as a sparse detector module.

[0035] In some embodiments, the at least one spacing module may include at least one second crystal module and / or at least one non-detection module. For example, the at least one spacing module may include at least one second crystal module. For another example, the at least one spacing module may include at least one non-detection module. For another example, the at least one spacing module may include a combination of at least one non-detection module and at least one second crystal module. In some embodiments, the at least two first crystal modules may be spaced apart (such as randomly or regularly) by at least one of the at least one second crystal module and / or the at least one non-spacer module. For example, the at least one second crystal module may space the at least two first crystal modules according to a certain rule, and the at least one non-detection module may randomly space the at least two first crystal modules. For another example, the at least one second crystal module and the at least one non-detection module may space the at least two first crystal modules randomly or according to a certain rule. Figure 2 For example, the at least two first crystal modules, the at least one second crystal module and a part of the at least one non-detection module may adopt any one of the arrangements shown in a1.

[0036] In some embodiments, at least two first crystal modules may be configured to detect a first portion of photons and generate a first scintillation. At least one second crystal module may be configured to detect a second portion of photons and generate a second scintillation. At least one non-detection module does not have the ability to detect photons, that is, the non-detection module cannot detect photons projected onto it. In some embodiments, each of the at least two first crystal modules has a first detection capability (that is, the ability to detect photons and / or generate scintillation). Each of the at least one second crystal module has a second detection capability (that is, the ability to detect photons and / or generate scintillation). The second detection capability may be less than the first detection capability, that is, for the same incident photons, a first crystal module can detect more photons or generate more scintillation than a second crystal module. For more description of the first detection capability or the second detection capability, see Figure 6It should be noted that, in some embodiments, the photon may include only the first and second parts described above. In some embodiments, in addition to the first and second parts described above, the photon may also include other parts, such as the photon part that is not detected by the detector.

[0037] In some embodiments, the detection capability of a crystal module may be related to the type of material it is composed of. In some embodiments, the first crystal module and / or the second crystal module may be composed of one or a combination of materials selected from the group consisting of cerium-doped yttrium lutetium silicate (LYSO), cerium-doped lutetium silicate (LSO), bismuth germanate (BGO), sodium iodide, cesium iodide, gadolinium silicate, calcium fluoride, cesium fluoride, and barium fluoride. For example, the first crystal module may be composed of LYSO, and the second crystal module may be composed of BGO (whose detection capability is lower than that of LYSO). In another example, the first crystal module may be composed of LSO, and the second crystal module may be composed of BGO (whose detection capability is lower than that of LSO). In another example, the first crystal module may be composed of cesium iodide, and the second crystal module may be composed of sodium iodide (whose detection capability is lower than that of cesium iodide). In some embodiments, materials with greater detection capability may also be more expensive. Therefore, by replacing part of the first crystal module with the second crystal module, the cost of the detector assembly can be reduced compared to a detector assembly composed solely of the first crystal module.

[0038] In some embodiments, the non-detection module may be composed of one or a combination of a light-transmitting material (such as glass), air (i.e., the non-detection module is vacant). For example, each of at least one non-detection module may be vacant. For another example, each of at least one non-detection module may be composed of a light-transmitting material. For another example, part of at least one non-detection module may be vacant, and another part of at least one non-detection module may be made of a light-transmitting material. In some embodiments, the selected light-transmitting material or vacant setting is cheaper than the material constituting the first crystal module or the material constituting the second crystal module. Therefore, compared with a detector assembly composed only of the first crystal module and / or the second crystal module, the cost of the detector assembly can be further reduced by introducing a non-detection module to replace part of the first crystal module and / or the second crystal module.

[0039] In some embodiments, each of the at least two first crystal modules or the at least one second crystal module may include at least two crystal units. The number of the at least two crystal units may be greater than a threshold, such as 100, 225, 400, etc. In some embodiments, the at least two crystal units may be arranged in a matrix, such as 10*10, 15*15, 20*20, etc. Each crystal unit may be composed of one or a combination of cerium-doped yttrium lutetium silicate, cerium-doped lutetium silicate, bismuth germanate, sodium iodide, cesium iodide, gadolinium silicate, calcium fluoride, cesium fluoride, barium fluoride, etc. In some embodiments, the at least two first crystal modules may include at least two first crystal units. The at least two second crystal modules may include at least two second crystal units. When manufacturing the crystal modules, the crystals may be directly cut to the size of the first crystal module or the second crystal module. Compared to cutting to the size of the first crystal unit or the second crystal unit, the manufacturing process is simpler and the cost of manufacturing the detector assembly can be reduced.

[0040] In some embodiments, the dimensions (e.g., volume, length, width, height) of a second crystal module or the dimensions (e.g., volume, length, width, height) of a non-detection module can be the same as or different from the dimensions (e.g., volume, length, width, height) of the first crystal module. In some embodiments, at least one non-detection module can include at least two non-detection units. The dimensions (e.g., volume, length, width, height) of a second crystal unit or the dimensions (e.g., volume, length, width, height) of a non-detection unit can be the same as or different from the dimensions (e.g., volume, length, width, height) of the first crystal unit. In some embodiments, to simultaneously ensure image quality and reduce the manufacturing cost of the detector assembly, the number of first crystal units in the detector module can account for 10%-99%, 30%-99%, 50%-80%, etc., of the sum of the number of first crystal units, the number of second crystal units, and the number of non-detection units in the detector module. The number of second crystal units in the detector module can account for 10%-99%, 30%-99%, 50%-80%, etc., of the sum of the number of second crystal units and the number of non-detection units in the detector module. For example, if the first crystal unit is made of LYSO and the second crystal unit is made of BGO, and each accounts for 50%, the cost of the detector assembly can be 2 / 3 of that of a detector assembly composed solely of LYSO. For another example, if the first crystal unit is made of LYSO and the second crystal unit is made of BGO, with the non-detection module left vacant, and each accounts for 1 / 3, the cost of the detector assembly is 4 / 9 of that of a detector assembly composed solely of LYSO.

[0041] The above description of the detector module structure is for illustrative purposes only and is not restrictive. In some embodiments, each of the first crystal module, the second crystal module and the non-detection module may include at least one unit. In some embodiments, each of the first crystal module, the second crystal module and the non-detection module may include only one unit, that is, the first crystal unit in the detector module may be spaced apart by the second crystal unit and / or the non-detection unit (such as randomly or regularly). In some embodiments, the number of first crystal units included in each first crystal module, the number of second crystal units included in each second crystal module and / or the number of non-detection units included in each non-detection module may be the same or different. For example, the number of first crystal units included in each first crystal module is at least two. The number of second crystal units included in each second crystal module is at least one. The number of non-detection units included in each non-detection module is at least one.

[0042] In some embodiments, first imaging data can be generated based on a first portion of detected photons or a first scintillation. The first imaging data can include first imaging sub-data corresponding to the portion of photons or scintillation detected by each first crystal module. Second imaging data can be generated based on a second portion of detected photons or a second scintillation. The second imaging data can include second imaging sub-data corresponding to the portion of photons or scintillation detected by each second crystal module. At least a portion of the first imaging data and the second imaging data can be used to generate an image. In some embodiments, an image can be generated using only the first imaging data. In this case, to reduce the cost of the detector assembly, the spacing module can include a non-detection module and / or a second crystal module made of a less expensive material. In some embodiments, an image can be generated using the first imaging data and the second imaging data. In some embodiments, the image can be generated based on a reconstruction algorithm. Exemplary reconstruction algorithms can include a maximum likelihood-maximum expectation (MLEM) algorithm, an ordered subset expectation maximization (OSEM) algorithm, a filtered back projection (FBP) algorithm, or the like, or any combination thereof.

[0043] Since the detection capability of the second crystal module is less than that of the first crystal module, during the detection process, assuming that the incident photon intensity is the same, the number of scintillation (or photon) detected by the second crystal module may be less than the number of scintillation (or photon) detected by the first crystal module, resulting in the second imaging data having a quality worse than the first imaging data. In order to ensure or improve the quality of the image, the first imaging data may be used to correct the second imaging data, and an image may be generated using at least a portion of the first imaging data and the corrected second imaging data. In some embodiments, a specific second crystal module (such as Figure 3 For example, the first crystal module adjacent to the middle block 310 can be used. Figure 3The first imaging sub-data corresponding to the first crystal module (blocks 312 and 314) is corrected by the second imaging sub-data corresponding to the second crystal module. "Adjacent" as used herein may mean that the number of modules between the first crystal module and the second crystal module is less than a number threshold (such as 1, 2, 3) or the distance is less than a distance threshold. In some embodiments, the number threshold or the distance threshold may be determined based on parameters of the detector assembly (such as the size of the first crystal module, the size of the second crystal module, the detection capability of the first crystal module, and the detection capability of the second crystal module). For more description of correcting the second imaging data and / or generating an image, see below Figure 6 The description is not repeated here.

[0044] In some embodiments, as described above, the non-detection module does not have the ability to detect photons, that is, it cannot detect the photons incident on it, which reduces the sensitivity of the detector assembly and may affect the quality of the image. In order to ensure or improve the quality of the image, at least a portion of the first imaging data or the second imaging data (or the corrected second imaging data) can be used to estimate the third imaging data corresponding to at least one non-detection module, and the first imaging data, the corrected second imaging data or at least a portion of the third imaging data can be used to generate an image. In some embodiments, a specific non-detection module (such as Figure 3 For example, the first crystal module adjacent to it (e.g. Figure 3 The third imaging sub-data corresponding to the non-detection module is estimated based on at least a portion of the first imaging sub-data corresponding to the non-detection module or the corrected second imaging sub-data corresponding to the adjacent second crystal module (blocks 322, 324, and 326). "Adjacent" as used herein may refer to the number of modules between the first crystal module or the second crystal module and the non-detection module being less than a number threshold (such as 1, 2, 3) or the distance being less than a distance threshold. In some embodiments, the number threshold or the distance threshold may be determined based on parameters of the detector assembly (such as the size of the non-detection module, the size of the first crystal module, the size of the second crystal module, the detection capability of the first crystal module, and the detection capability of the second crystal module). For more description on estimating the third imaging data and / or generating an image, see below Figure 6 The description is not repeated here.

[0045] In some embodiments, the detector assembly may further include a sensor configured to detect the first scintillation and / or the second scintillation and / or generate corresponding computer-readable signals. The imaging data (e.g., the first imaging data and the second imaging data) may be generated based on the detected first scintillation and / or the second scintillation and / or the generated computer-readable signals.

[0046] In some embodiments, the sensor can be directly connected to the detector module or indirectly connected through a light-conducting element (such as an optical fiber). In some embodiments, the modules included in the detector module (such as the first crystal module, the second crystal module, and the non-detection module) and the modules included in the sensor can be connected one-to-one. In this case, the number of modules included in the sensor and the number of modules included in the detector module are the same. In some embodiments, the modules included in the detector module (such as the first crystal module, the second crystal module, and the non-detection module) and the modules included in the sensor can be connected many-to-one. In this case, the number of modules included in the detector module is greater than the number of modules included in the sensor. In some embodiments, the modules included in the sensor are only connected to at least two first crystal modules and at least a portion of at least one second crystal module, and are not connected to at least one non-detection module.

[0047] In some embodiments, each module in the sensor may be constructed using the same components, such as a silicon photomultiplier (SiPM) (such as a digital silicon photomultiplier), a photomultiplier tube (PMT), a photodiode (such as an avalanche photodiode), an active pixel sensor, a charge-coupled device, a photoresistor, a phototransistor, etc. In some embodiments, the sensor may include at least one first sensing module and at least one second spacing module. Similar to the at least two first crystal modules and the at least one first spacing module, the at least one second spacing module is configured to (such as randomly or regularly) space the at least one first sensing module apart. Compared to the at least one first sensing module, the at least one second spacing module may be constructed using lower-cost components or materials. Therefore, compared to a detector assembly composed only of first sensing modules, the cost of the detector assembly may be reduced by introducing a second spacing module to replace part of the first sensing modules. In some embodiments of the present specification, a sensor including a second spacing module may also be referred to as a sparse sensor.

[0048] In some embodiments, the first crystal module can be connected to the first sensor module, and the second crystal module can be connected to the second sensor module. In some embodiments, the first crystal module and the second crystal module can be connected to the first sensor module respectively. In some embodiments, a barrier material can be placed between the non-detection module and the sensor to prevent radiation (such as photons) from damaging the sensor.

[0049] In some embodiments, the at least one second spacing module may include at least one second sensing module and / or at least one second non-detection module. For example, the at least one second spacing module may include at least one second sensing module. For another example, the at least one second spacing module may include at least one second non-detection module. For another example, the at least one second spacing module may include a combination of at least one second detection module and at least one second sensing module. In some embodiments, the at least one first sensing module may be spaced apart by at least one of the at least one second sensing module or the at least one second non-detection module (such as randomly or regularly). For example, the at least one second sensing module may be spaced apart from the at least one first sensing module according to a certain rule, and the at least one second non-detection module may be randomly spaced apart from the at least one first sensing module. For another example, the at least one second sensing module and the at least one second non-detection module may be spaced apart from the at least one first sensing module randomly or according to a certain rule.

[0050] In some embodiments, at least one first sensing module may be configured to detect a first portion of a first scintillation and a second scintillation; that is, at least one first sensing module may detect at least a portion of the first scintillation and / or at least a portion of the second scintillation. At least one second sensing module may be configured to detect a second portion of the first scintillation and the second scintillation; that is, at least one second sensing module may detect at least a portion of the first scintillation and / or at least a portion of the second scintillation. At least one second non-detection module does not have the ability to detect photons, that is, the second non-detection module cannot detect scintillation projected thereon. In some embodiments, each of the at least one first sensing module has a third detection capability (i.e., the ability to detect scintillation). Each of the at least one second sensing module has a fourth detection capability (i.e., the ability to detect scintillation). The fourth detection capability may be less than the second detection capability.

[0051] In some embodiments, the detection capability of a sensing module may be related to the type of components that constitute it. In some embodiments, the first sensing module and / or the second sensing module may be composed of one or a combination of a silicon photomultiplier (SiPM) (such as a digital silicon photomultiplier SiPM), a photomultiplier tube (PMT), a photodiode (such as an avalanche photodiode), an active pixel sensor, a coupled device, a photoresistor, a phototransistor, etc. For example, the first sensing module may be composed of a SiPM, and the second sensing module may be composed of a PMT. In some embodiments, the stronger the detection capability of an element, the more expensive it may be. Therefore, compared to a detector assembly composed only of the first sensing module, the cost of the detector assembly can be reduced by introducing the second sensing module to replace part of the first sensing module.

[0052] In some embodiments, the second non-detection module may be composed of one or a combination of a light-transmitting material (such as glass), air (i.e., the second non-detection module is empty). For example, each of the at least one second non-detection module may be empty. For another example, each of the at least one second non-detection module may be composed of a light-transmitting material. For another example, part of the at least one second non-detection module may be empty, and another part of the at least one second non-detection module may be made of a light-transmitting material. In some embodiments, the selected light-transmitting material or the empty setting is cheaper than the material constituting the first sensing module or the material constituting the second sensing module. Therefore, compared with the detector assembly composed of only the first sensing module and / or the second sensing module, the cost of the detector assembly can be further reduced by introducing the second non-detection module to replace part of the first sensing module and / or the second sensing module.

[0053] In some embodiments, each of the at least one first sensing module or the at least one second sensing module may include at least one sensing unit (e.g., at least two sensing units). In some embodiments, the size (e.g., volume, length, width, height) of a second sensing module or the size (e.g., volume, length, width, height) of a second non-detection module may be the same as or different from the size (e.g., volume, length, width, height) of the first sensing module. In some embodiments, the at least one second non-detection module may include at least two second non-detection units. The size (e.g., volume, length, width, height) of a second sensing unit or the size (e.g., volume, length, width, height) of a second non-detection unit may be the same as or different from the size (e.g., volume, length, width, height) of the first sensing unit.

[0054] It should be noted that the above description is provided for illustrative purposes only and is not intended to limit the scope of this specification. In addition to its application in the field of medical imaging, the above detector assembly can also be used in security inspection, scientific experiments, energy detection, nuclear cameras, gas detection and other fields.

[0055] Figure 5 FIG. 5 is an exemplary module diagram of an imaging system according to some embodiments of the present disclosure. The imaging system 500 may include a first determination module 510 , a second determination module 520 , a correction module 530 , and a generation module 540 .

[0056] Imaging system 500 (such as imaging system 100) may include an imaging device (such as imaging device 110). The imaging device may include a detector assembly. The detector assembly may include at least two first crystal modules and at least one second crystal module. The at least two first crystal modules may be configured to detect a first portion of photons and generate a first scintillation. The at least one second crystal module may be configured to detect a second portion of photons and generate a second scintillation, and may be spaced (e.g., randomly or regularly) apart from the at least two first crystal modules. In some embodiments, each of the at least two first crystal modules may have a first detection capability (i.e., the ability to detect photons and / or generate scintillation), and each of the at least one second crystal module may have a second detection capability (i.e., the ability to detect photons and / or generate scintillation). The second detection capability is less than the first detection capability, that is, for the same incident photons, a first crystal module may be able to detect more photons or generate more scintillation than a second crystal module. In some embodiments, the detector assembly may include at least one non-detection module that does not have a detection capability. At least two first crystal modules may be separated by at least one of at least one second crystal module or at least one non-detection module. For more information about the imaging system 500, imaging device, or detector assembly, see Figure 1-Figure 3 , I will not go into details here.

[0057] The first determination module 510 can be configured to generate first imaging data based on the first portion of the detected photons and / or the first scintillation. In some embodiments, the first imaging data may include first imaging sub-data corresponding to the photon portion or scintillation portion detected by each first crystal module. Exemplary first imaging data may include photon data (e.g., position, time, and number), scintillation data (e.g., position, time, and number), coincidence event data (e.g., position, time, and number), line of response (LOR) data (e.g., position, time, and number), etc. detected by each first crystal module, or any combination thereof.

[0058] The second determination module 520 can be configured to generate second imaging data based on the second portion of the detected photons and / or the second scintillation. Similar to the first imaging data, exemplary second imaging data may include photon data (e.g., position, time, and number), scintillation data (e.g., position, time, and number), coincidence event data (e.g., position, time, and number), line of response (LOR) data (e.g., position, time, and number), etc. detected by each second crystal module, or any combination thereof.

[0059] The correction module 530 may be configured to correct the second imaging data based on the first imaging data. Figure 1As described in , since the detection capability of the second crystal module is worse than that of the first crystal module, during the detection process, assuming that the incident photon intensity is the same, the number of scintillation (or photon) detected by the second crystal module may be less than the number of scintillation (or photon) detected by the first crystal module, resulting in the quality of the second imaging data being worse than the quality of the first imaging data. In some embodiments, the second imaging data can be corrected based on the first detection capability of the first crystal module, the second detection capability of the second crystal module, and the first imaging data. For more description on correcting the second imaging data based on the first imaging data, see Figure 6 and its related descriptions.

[0060] The generation module 540 may be configured to generate an image based on at least a portion of the first imaging data and the corrected second imaging data. In some embodiments, a reconstruction algorithm may be used to generate the image. Exemplary reconstruction algorithms may include a maximum likelihood-maximum expectation (MLEM) algorithm, an ordered subset expectation maximization (OSEM) algorithm, a filtered back projection (FBP) algorithm, or any combination thereof.

[0061] It should be understood that the system and its modules shown can be implemented in various ways. For example, in some embodiments, the system and its modules can be implemented by hardware, software, or a combination of software and hardware. Among them, the hardware portion can be implemented using dedicated logic; the software portion can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated hardware. Those skilled in the art will understand that the above-mentioned methods and systems can be implemented using computer-executable instructions and / or contained in processor control code, for example, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The system and its modules of this specification can be implemented not only by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., but can also be implemented by software executed by various types of processors, or by a combination of the above-mentioned hardware circuits and software (for example, firmware).

[0062] It should be noted that the above description of imaging system 500 and its modules is for convenience only and does not limit this specification to the illustrated embodiments. It is understood that, after understanding the principles of the system, those skilled in the art may arbitrarily combine the modules or form subsystems connected to other modules without departing from these principles. For example, first determination module 510, second determination module 520, correction module 530, and generation module 540 may share a single storage module, or each module may have its own storage module. Such variations are within the scope of this specification.

[0063] Figure 6 is a flow chart of an imaging method corresponding to an exemplary imaging system according to some embodiments of the present disclosure.

[0064] An imaging system (such as imaging system 100) may include an imaging device (such as imaging device 110). The imaging device may include a detector assembly. The detector assembly may include at least two first crystal modules and at least one second crystal module. The at least two first crystal modules may be configured to detect a first portion of photons and generate a first scintillation. The at least one second crystal module may be configured to detect a second portion of photons and generate a second scintillation, and may be spaced apart (such as randomly or regularly) from the at least two first crystal modules. In some embodiments, each of the at least two first crystal modules may have a first detection capability (i.e., the capability to detect photons and / or generate scintillation), and each of the at least one second crystal module may have a second detection capability (i.e., the capability to detect photons and / or generate scintillation). The second detection capability is less than the first detection capability, that is, for the same incident photons, a first crystal module may be able to detect more photons or generate more scintillation than a second crystal module. In some embodiments, the detector assembly may include at least one non-detection module that does not have a detection capability. The at least two first crystal modules may be spaced apart by at least one of the at least one second crystal module or the at least one non-detection module. For more description of the imaging system, imaging device, or detector assembly, see Figure 1-Figure 3 , I will not go into details here.

[0065] At 610, first imaging data is generated based on the first portion of the detected photons and / or the first scintillation. In some embodiments, the first imaging data may include first imaging sub-data corresponding to the photon portion or scintillation portion detected by each first crystal module. Exemplary first imaging data may include photon data (e.g., position, time, number), scintillation data (e.g., position, time, number), coincidence event data (e.g., position, time, number), line of response (LOR) data (e.g., position, time, number), etc., or any combination thereof, detected by each first crystal module. Coincidence event data and / or LOR data detected by the crystal module may be determined based on the photon data or scintillation data detected by the crystal module. In some embodiments, the location information of the coincidence event may include the locations of the two crystal modules that detected a pair of photons corresponding to the coincidence event, the location where the coincidence event occurred, etc. In some embodiments, coincidence events on the line of response may be evenly distributed between the two crystal modules and the crystal modules located between them on the line of response. In some embodiments, if the time information of the coincident event includes the flight time of the coincident event, which includes the time when a pair of photons corresponding to the coincident event are detected by two crystal modules respectively, the location of the coincident event can be determined based on the time difference between the two (such as on which crystal module annihilation occurs, it can be considered that the coincident event is detected by the crystal module).

[0066] At 620, second imaging data is generated based on the second portion of the detected photons and / or the second scintillation. Similar to the first imaging data, exemplary second imaging data may include photon data (e.g., position, time, and number), scintillation data (e.g., position, time, and number), coincidence event data (e.g., position, time, and number), line of response (LOR) data (e.g., position, time, and number), and the like, or any combination thereof, detected by each second crystal module. For further description, see operation 610 and are not further elaborated here.

[0067] At 630, the second imaging data is corrected based on the first imaging data. Figure 1 As described in [ ], because the detection capability of the second crystal module is inferior to that of the first crystal module, during the detection process, assuming the incident photon intensity is the same, the number of scintillations (or photons) detected by the second crystal module may be less than the number of scintillations (or photons) detected by the first crystal module, resulting in the second imaging data having a lower quality than the first imaging data. In some embodiments, the second imaging data can be corrected based on the first detection capability of the first crystal module, the second detection capability of the second crystal module, and the first imaging data.

[0068] In some embodiments, an imaging device can be used to scan a uniform rod source to obtain rod source values ​​corresponding to the crystal modules. The tracer distribution at any location on the uniform rod source is (substantially) uniform, meaning that the photon intensity incident on each crystal module is (substantially) the same. The rod source values ​​corresponding to the crystal modules can be correlated with the data actually detected by the crystal modules (e.g., number of photons, number of scintillation events, number of coincidence events, number of LORs). For example, the greater the number of photons or coincidence events detected by a crystal module, the greater the rod source value corresponding to that crystal module, indicating greater detection capability of that crystal module. Therefore, the rod source values ​​corresponding to a crystal module can be used to characterize the detection capability of the crystal module. As used herein, "substantially the same" can mean that the deviation between two elements (e.g., tracer distribution at different locations on the rod source and incident light intensity on two crystal modules) is less than a certain threshold, such as 1%, 3%, or 5%.

[0069] In some embodiments, a lookup table corresponding to the detector module can be constructed based on the first detection capability, the second detection capability and the arrangement of the detector modules (eg Figure 4 The query table corresponding to the detector module portion is shown). The query table includes at least two grid blocks, which correspond one-to-one to the positions of the modules included in the detector module (such as at least two first crystal modules, at least one second crystal module, and at least one non-detection module). The grid block corresponding to a first crystal module can be filled with a numerical value (such as the number "1") used to characterize the first detection capability of the first crystal module, the grid block corresponding to a non-detection module can be filled with a numerical value (such as the number "0") used to characterize the detection capability of the non-detection module, and the grid block corresponding to a second crystal module can be filled with a numerical value (such as a number between 0 and 1, such as 0.3, 0.5, or 0.8) used to characterize the second detection capability of the second crystal module.

[0070] For each second imaging sub-data detected by at least one second crystal module, the second imaging sub-data may be corrected based on the first imaging sub-data corresponding to the adjacent first crystal module, the detection capability of the first crystal module, or at least a portion of the detection capability of the second crystal module. For example, the second imaging sub-data may be corrected using the following formula (1):

[0071]

[0072] Wherein, C1 represents the photon data (such as the number of photons) detected by the second crystal module, TC1 represents the rod source value of the second crystal module, TC2 and TC3 represent the rod source values ​​of the first crystal module adjacent to the second crystal module, and C new,1 represents the photon data after correction of the second crystal module.

[0073] In some embodiments, if the detector assembly includes at least one non-detection module as described above, the third data corresponding to the at least one non-detection module can be estimated based on at least a portion of the first imaging data and the second imaging data (or the corrected second imaging data). In some embodiments, for each corresponding third imaging sub-data of at least one non-detection module, the third imaging sub-data can be estimated based on the first imaging sub-data corresponding to the first crystal module adjacent to the non-detection module or the corrected second imaging sub-data corresponding to the adjacent second crystal module. In some embodiments, the statistical value (such as the average, median, interpolation) of at least a portion of the first imaging sub-data corresponding to the first crystal module adjacent to the non-detection module or the corrected second imaging sub-data corresponding to the adjacent second crystal module can be designated as the third imaging sub-data. For example, the third imaging sub-data can be estimated based on the following formula (2) or formula (3):

[0074] C1=mean(C2,C3,C4) (2)

[0075] LOR1=mean(LOR2,LOR3,LOR4) (3)

[0076] Among them, C2, C3, C4 represent the photon data (such as the number of photons) corresponding to the first crystal module adjacent to the non-detection module, and C1 represents the estimated photon data (such as the number of photons) corresponding to the non-detection module, LOR2, LOR3, LOR4 represent the LOR data corresponding to the first crystal module adjacent to the non-detection module, and LOR new,1 Represents the estimated LOR data corresponding to the non-detection module.

[0077] At 640, an image is generated based on at least a portion of the first imaging data and the corrected second imaging data. In some embodiments, the image may be generated based on at least a portion of the first imaging data, the corrected second imaging data, or the third imaging data. In some embodiments, the image may be generated using a reconstruction algorithm. Exemplary reconstruction algorithms may include a maximum likelihood-maximum expectation (MLEM) algorithm, an ordered subset expectation maximization (OSEM) algorithm, a filtered back projection (FBP) algorithm, the like, or any combination thereof.

[0078] It should be noted that the above description of the imaging method 600 is for convenience of description only and is not restrictive. Operations 620-630 may be omitted. After determining the first imaging data, the second imaging data corresponding to the second crystal module or the third imaging data corresponding to the third crystal module may be estimated based on the first imaging data. In 640, an image may be generated based on at least a portion of the first imaging data, the estimated second imaging data, or the estimated third imaging data. For each of the at least one second crystal modules, the second imaging sub-data corresponding to the second crystal module may be estimated based on the first imaging sub-data corresponding to its adjacent first crystal module. In some embodiments, the statistical value (such as the average, median, or interpolation) of the first imaging sub-data corresponding to the adjacent first crystal module may be designated as the estimated second imaging sub-data. For example, the second imaging sub-data may be estimated by the following formula (4):

[0079] LOR5=mean(LOR6,LOR7,LOR8) (4)

[0080] Among them, LOR6, LOR7, and LOR8 represent LOR data corresponding to the first crystal module adjacent to the second crystal module, and LOR5 represents estimated LOR data corresponding to the second crystal module.

[0081] It should be understood that the system and its modules shown can be implemented in various ways. For example, in some embodiments, the system and its modules can be implemented by hardware, software, or a combination of software and hardware. Among them, the hardware portion can be implemented using dedicated logic; the software portion can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated hardware. Those skilled in the art will understand that the above-mentioned methods and systems can be implemented using computer-executable instructions and / or contained in processor control code, for example, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The system and its modules of this specification can be implemented not only by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., but can also be implemented by software executed by various types of processors, or by a combination of the above-mentioned hardware circuits and software (for example, firmware).

[0082] It should be noted that the above description of imaging system 500 and its modules is for convenience only and does not limit this specification to the illustrated embodiments. It is understood that those skilled in the art, after understanding the principles of the system, may arbitrarily combine the modules or form subsystems connected to other modules without departing from these principles. For example, model determination module 210, convolution kernel determination module 220, and scatter information determination module 230 may share a storage module, or each module may have its own storage module. Such variations are within the scope of this specification.

[0083] The present specification also provides a computer-readable storage medium storing computer instructions. When a computer reads the computer instructions from the storage medium, the computer executes an imaging method corresponding to the aforementioned imaging system. The imaging system includes: a detector assembly, the detector assembly including: at least two first crystal modules configured to detect a first portion of photons and generate a first scintillation, each of the at least two first crystal modules having a first detection capability; at least one second crystal module configured to detect a second portion of the photons and generate a second scintillation, and the at least two first crystal modules are randomly spaced apart, each of the at least one second crystal module having a second detection capability, and the second detection capability is less than the first detection capability; and a sensor connected to the at least two first crystal modules and / or the at least one second crystal module, the sensor configured to detect the first scintillation and / or the second scintillation. The imaging method includes: generating first imaging data based on the detected first scintillation; generating second imaging data based on the detected second scintillation; correcting the second imaging data based on the first imaging data; and generating an image based on at least a portion of the first imaging data and the corrected second imaging data.

[0084] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, various modifications, improvements, and revisions to this specification may be made by those skilled in the art. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0085] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0086] In addition, it will be understood by those skilled in the art that various aspects of this specification may be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product or combination of substances, or any new and useful improvements thereto. Accordingly, various aspects of this specification may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". In addition, various aspects of this specification may be represented as a computer product located in one or more computer-readable media, which includes computer-readable program code.

[0087] A computer storage medium may include a propagated data signal embodying the computer program code, for example, in baseband or as part of a carrier wave. The propagated signal may be in a variety of forms, including electromagnetic, optical, or any suitable combination thereof. A computer storage medium may be any computer-readable medium other than a computer-readable storage medium that can be connected to an instruction execution system, apparatus, or device to communicate, propagate, or transfer the program for use. The program code on the computer storage medium may be transmitted via any suitable medium, including radio, cable, fiber optic cable, RF, or similar media, or any combination of these.

[0088] The computer program codes required for the operation of the various parts of this specification 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, Fortran2003, Perl, COBOL2002, PHP, ABAP, dynamic programming languages ​​such as Python, Ruby and Groovy, or other programming languages. The program code can be run entirely on the user's computer, or as a separate software package on the user's computer, or partly on the user's computer and partly on a remote computer, or entirely on a remote computer or processing device. In the latter case, the remote computer can be connected to the user's computer through any network form, such as a local area network (LAN) or a wide area network (WAN), or connected to an external computer (e.g., via the Internet), or in a cloud computing environment, or used as a service such as software as a service (SaaS).

[0089] In addition, unless expressly stated in the claims, the order of the processing elements and sequences, the use of alphanumeric characters, or the use of other names described in this specification are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some embodiments of the invention that are currently considered useful 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. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the spirit and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing processing device or mobile device.

[0090] Similarly, it should be noted that, in order to simplify the presentation of this specification and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0091] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0092] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this specification is hereby incorporated by reference in its entirety. This includes application history documents that are inconsistent with or conflict with the content of this specification, as well as documents (currently or subsequently attached to this specification) that limit the broadest scope of the claims of this specification. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent or conflicting with the content of this specification, the descriptions, definitions, and / or terminology used in this specification will control.

[0093] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. An imaging method corresponding to an imaging system, characterized in that: The imaging system includes a detector assembly, the detector assembly including: at least two first crystal modules configured to detect a first portion of photons and generate a first scintillation, each of the at least two first crystal modules having a first detection capability; at least one second crystal module configured to detect a second portion of the photons and generate a second scintillation, each of the at least one second crystal module having a second detection capability, and the second detection capability being less than the first detection capability; at least one non-detecting module, wherein the at least two first crystal modules are separated by at least one of the at least one second crystal module or the at least one non-detecting module; and a sensor connected to the at least two first crystal modules and / or the at least one second crystal module, the sensor being configured to detect the first scintillation and / or the second scintillation, and the method comprising: generating first imaging data based on the detected first scintillation; generating second imaging data based on the detected second scintillation; correcting the second imaging data based on the first detection capability of the first crystal module, the second detection capability of the second crystal module, and the first imaging data; and An image is generated based on at least a portion of the first imaging data and the corrected second imaging data.

2. The imaging method according to claim 1, wherein Each of the at least two first crystal modules or the at least one second crystal module includes at least two crystal units.

3. The imaging method according to claim 2, wherein: Each of the at least two crystal units is composed of one of cerium-doped yttrium lutetium silicate, cerium-doped lutetium silicate, bismuth germanate, sodium iodide, cesium iodide, gadolinium silicate, calcium fluoride, cesium fluoride, and barium fluoride, or a combination thereof.

4. The imaging method according to claim 1, wherein The sensor comprises: at least one first sensing module configured to detect a first portion of the first scintillation and the second scintillation, each of the at least one first sensing module having a third detection capability; and At least one second sensing module is configured to detect a second portion of the first scintillation and the second scintillation, each of the at least one second sensing module has a fourth detection capability, and the fourth detection capability is less than the third detection capability.

5. The imaging method according to claim 4, wherein: The sensor further comprises: At least one second non-detection module, the at least one first sensing module is separated by at least one of the at least one second sensing module or the at least one second non-detection module.

6. The imaging method according to claim 4, wherein: Each of the at least one first sensing module or the at least one second sensing module includes at least two sensing units.

7. The imaging method according to claim 6, wherein: Each of the at least two sensing units is composed of one or a combination of a silicon photomultiplier and a photomultiplier tube.

8. The imaging method according to claim 5, wherein: Each of the at least one non-detection module or the at least one second non-detection module is composed of one or a combination of glass and air.

9. The imaging method according to claim 1, wherein The at least two first crystal modules include at least two first crystal units, The at least one second crystal module includes at least two second crystal units, The at least one non-detection module includes at least two non-detection units, and The number of the at least two first crystal units accounts for 30%-99% of the total number of the at least two first crystal units, the at least two second crystal units, and the at least two non-detection units.

10. The imaging method according to claim 1, wherein The first detection capability is determined based on a rod source value corresponding to the first crystal module, and the second detection capability is determined based on a rod source value corresponding to the second crystal module.

11. The imaging method according to claim 1, wherein Correcting the second imaging data based on the first detection capability of the first crystal module, the second detection capability of the second crystal module, and the first imaging data includes: For each second imaging sub-data detected by the at least one second crystal module, The second imaging sub-data is corrected based on the first imaging sub-data corresponding to the adjacent first crystal module, the first detection capability of the first crystal module, or the second detection capability of the second crystal module.

12. The imaging method according to claim 1, wherein The method further comprises: determining third imaging data corresponding to the at least one non-detection module based on at least a portion of the first imaging data, the second imaging data, or the corrected second imaging data; The image is generated based on at least a portion of the first imaging data and the third imaging data.

Images